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FIELD OF THE INVENTION
The present invention relates to fuel injection, and in particular to a method for controlling an electrostatic fuel injection unit for use in combustion systems.
BACKGROUND OF THE INVENTION
Conventional air-fuel delivery systems can be broadly divided into two types: Carburetion and fuel injection. The carburetion system only permits the use of light fuel oil and is becoming increasingly complex in mechanism because of the need to meet the recent emission control requirements with the consequential increase in cost. Fuel injection for Diesel engines employs a fuel pump for compressing air and, at the point of maximum compression, fuel oil is injected into the combustion chamber and ignition takes place as a result of the high temperature which has been created. In electronic fuel injection, the fuel injectors are essentially solenoid actuated on/off poppet valves incorporating pintles designed for metering and atomization of light fuel oil, which requires precision in machining and becomes costly in mass production.
Fuel injection operating on the principle of electrostatic attraction and repulsion as described in copending U.S. patent application Ser. No. 778,944 filed on Mar. 10, 1977 and assigned to the same assignee of the present invention, is advantageous over the prior art fuel injection in that the disclosed fuel injection permits the use of both light and heavy fuel oils, is simple in construction and easy to regulate the amount of fuel to be injected.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for controlling an electrostatic fuel injection unit of the afore-said copending U.S. patent application.
Another object of the invention is to provide a method for controlling an electrostatic fuel injector having an accelerator electrode for accelerating ejected fuel and a control electrode in which the control electrode is biased with respect to the accelerator electrode to modulate the amount of ejected fuel in response to a detected engine operating parameter such as accelerator pedal depression.
A further object of the present invention is to provide a method for controlling a plurality of electrostatic fuel injection units in succession to achieve a wide range of variations of fuel quantity to be injected.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of an embodiment of the invention;
FIG. 2 is a cross-sectional view of an electrostatic fuel injector used in the embodiment of FIG. 1;
FIG. 3 is a cross-sectional view taken along the lines 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view taken along the lines 4--4 of FIG. 2;
FIG. 5 is a cross-sectional view of an air intake pipe of an internal combustion engine with a plurality of fuel injection units mounted therein;
FIG. 6 is a cross-sectional view taken along the lines 6--6 of FIG. 5; and
FIG. 7 is a circuit block diagram for operating the injection units of FIG. 5;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a fuel combustion system embodying the present invention is illustrated as comprising an air intake pipe 10, a fuel supply container 12 for holding fuel 13 and a fuel injection unit 14 disposed in the intake pipe 10 in communication with the fuel supply container 12 through conduit 32.
As clearly illustrated in FIGS. 2 to 4, the fuel injection unit or injector 14 comprises a housing 16, an apertured accelerator electrode 18 disposed at the forward end of the housing, an apertured control electrode 20 spaced downwardly from the accelerator electrode 18 and a plurality of parallel fuel delivery nozzles 22 embedded into an insulating body 24. The apertures 26 of accelerator electrode 18 are coaxially aligned with apertures 28 of control electrode 20. Each nozzle 22 is formed by a conductive threadlike tubular member and extends upwardly into the bore 28 and is coaxially aligned therewith. The upstream end of each nozzle is in communication with the fuel supply container 12 through a chamber 30 connected to the conduit 32.
The combustion system includes a first voltage control circuit 34 and a second voltage control circuit 36. The first voltage control circuit 34 comprises a voltage source 38 with a DC potential of the order of several hundreds volts, a variable resistor 40 with its opposite ends connected across the terminals of the voltage source 38, and an electromechanical transducer 42 of the type which translates an input signal applied thereto into a corresponding mechanical movement. The wiper terminal of the variable resistor 40 is operatively connected by a linkage indicated by broken lines 44 to the transducer 42. A point intermediate the ends of the variable resistor 40 is connected to the accelerator electrode 18 of the injector 14 through lead 46 and the wiper terminal of the resistor 40 is connected to the control electrode 20 through lead 48.
Similarly, the second voltage control circuit 36 comprises a voltage source 50 with a DC potential of the order of from several kilovolts to several tens of kilovolts, and a variable resistor 52 with its opposite ends connected across the terminals of the voltage source 50 and its wiper terminal connected through leads 56 and 57 to the tube 22 which are connected together. A charging electrode 54 is immersed in the fuel container 12 and connected if necessary to the wiper terminal 62 of resistor 52. The intermediate point of the resistor 52 is connected through lead 58 to the accelerator electrode 18 of the injector 14. An electromechanical transducer 60 is provided to translate an input signal applied thereto into a corresponding mechanical movement with which the wiper terminal of resistor 52 is made to move along the length of the resistor 52 through a mechanical linkage indicated by broken lines 62.
When the wiper terminal of each variable resistor is positioned at the intermediate point of the corresponding resistor, there is no potential developed across the accelerator and control electrodes 18 and 20 as well as across the accelerator electrode 18 and the charging electrode 54. With the wiper terminal of resistor 40 being positioned at the intermediate point, a shift of wiper terminal of resistor 52 to the right of its intermediate point will generate a bias potential across the charging electrode 54 and the accelerator electrode 18, so that fuel 13 is positively charged with respect to the accelerator electrode 18. The charged fuel is led through the conduit 32 and tubular members 22 of the injector 14 for subsequent ejection into the intake passage 10. At the delivery end of the threadlike tubes 22 the charged fuel tends to atomize by electrostatic repulsion between the charged particles and is attracted by the negative potential at the accelerator electrode 18 and accelerated at such high speeds as to pass through the apertures of the electrode 18. The ejected atomized fuel is then mixed with the inducted air and passed into a combustion chamber (not shown). Fuel will be negatively charged when the wiper terminal of resistor 52 is moved to the left of its intermediate point and the charged fuel is ejected in the same manner as when positively charged.
The amount of fuel ejected can be varied by controlling the accelerating potential between the accelerator electrode 18 and the charging electrode 54 in response to a signal derived from a detected operating parameter of the combustion system representing the throttle position.
The electromechanical transducer 60 receives the signals representing such operating parameters from sensors (not shown) and converts the signals into a corresponding mechanical movement which is transmitted by a mechanical linkage 62 to the wiper terminal of resistor 52.
Fuel control is also achieved by varying the potential across the accelerator and control electrodes 18 and 20. Assume that the accelerator electrode 18 is biased at a given negative potential with respect to the charging electrode 54, the application of negative potential of the order of several hundred volts to the control electrode will assist in ejecting the fuel particles. Conversely, the application of a reverse bias potential to the control electrode will retard the fuel particles and the amount of ejected fuel decreases in proportion to the reverse control bias until a cut-off level is reached.
The control potential at the control electrode 20 with respect to the accelerator electrode 18 may be modulated with detected engine operating parameters such as engine temperature, engine RPM and intake vacuum pressure. The sensed parameters are fed into the electromechanical transducer 42, where the signals are converted into a corresponding movement of the wiper terminal of resistor 40. When the wiper terminal is positioned to the right of the intermediate point, the control electrode 20 will be biased positive with respect to the accelerator electrode and biased negative when the wiper terminal is positioned to the left of the intermediate point.
It will be understood that at a given accelerating potential the delivered fuel quantity increases when the control electrode is biased opposite to the accelerator electrode and decreases when the polarity is reversed.
It will be appreciated that the accelerating and controlling potentials may be simultaneously controlled to provide more accurate fuel delivery control than is possible with the modulation of one of the potentials.
In FIGS. 5 to 7, the fuel injector 14 is shown as employed in a vehicle internal combustion engine. In FIG. 5, an air intake pipe 70 is formed to accommodate a plurality of injector units 14 of the type as described above. The injectors 14 are stacked one upon another and arranged radially as best seen in FIG. 6. Air is inducted through a flared end of the pipe 70 to pass through the fuel delivery ends of the injectors toward the throttle valve 72 mounted downstream of the injectors 14. Fuel is supplied from a source (not shown) into a chamber 74 formed between the rear end of the injectors and the adjacent wall of the pipe 70.
As illustrated in FIG. 7, the accelerator electrodes of the injector units 14-1 to 14-4 (injectors 14-5 to 14-8 are omitted for the sake of simplicity) are connected together to one terminal of the voltage control circuit 36 as previously described and to a control circuit 78 through lead 76. Similarly, the tubular members of the injectors are connected together to the other terminal of the voltage control circuit 36 through lead 80.
The voltage control circuit 78 includes a voltage source 82 of several hundreds volts and an electromechanical transducer 84 of the type as previously described. A variable resistor 86 is provided which includes four resistance circuit branches having four resistance elements A, B, C and D of equal resistance value and length. The resistance A is positioned at the leftmost position and connected to a strip of conductor element a having three times the length of the resistance A. The resistance B is displaced from the leftmost position by the length of each resistance or unit length and connected at one end to a conductive strip b1 and at the other end to a conductive strip b2. The conductive strip b1 has the unit length and the strip b2 twice that length. The resistance C is displaced by twice the unit length from the leftmost position and connected at one end to a conductive strip c1 having twice the unit length and at the other end to a conductive strip c2 of the unit length. The resistance D is positioned at the rightmost position and connected at one end to a strip of conductor d having three times the unit length. The leftmost ends of the resistance circuits are connected together to the positive terminal of the voltage source 82 and the rightmost ends are connected together to the negative terminal of the voltage source 82. These resistances have their intermediate points connected together to the accelerator electrodes of the injectors.
Wiper terminals 90A, 90B, 90C and 90D are provided for the resistance circuit branches and ganged together for joint movement along the length of the corresponding resistance circuits. The wiper terminals 90A to 90D are connected to the control electrodes of the injectors 14-1, 14-2, 14-3 and 14-4 through leads 91, 92, 93 and 94, respectively, and in turn operatively connected through a linkage 95 to the electromechanical transducer 84.
Engine operating parameters such as coolant temperature and intake vacuum are sensed by detectors (not shown) and supplied to the transducer 84, which in turn causes the wiper terminals 90A to 90D to be moved simultaneously by an amount proportional to the applied input signal in the direction as indicated by the arrows in FIG. 7.
Assume that the accelerator electrodes of all the injectors are biased at a given negative potential relative to the corresponding fuel charging tubular electrodes, and that all the wiper terminals are positioned at the leftmost position, the control electrodes are all equally biased at a positive potential with respect to the corresponding accelerator electrodes such that each injector is biased to the cut-off level. As a result, no fuel is ejected from the injectors. As the wiper terminals are shifted to the right slightly so that only wiper 90A is in contact with the resistance A, the control bias applied to injector 14-1 rises above the cut-off level and fuel starts at zero and increases with the rightward movement of the wiper 90A until it comes to the conductive strip a. When the wiper terminal 90B reaches the resistance B, the control bias applied to injector 14-2 will cause fuel to start at zero, the amount of which increases with the wiper movement until the conductive strip b2 is reached.
Therefore, while the wiper 90B is in contact with the resistance B, the injector 14-1 is operated at its maximum capacity and the injector 14-2 is operated in a range from minimum to maximum capacities, and the other injectors remain cut off. In like manner, a further movement of wipers to the right will cause the injector 14-3 and then injector 14-4 to successively start operating in a range from minimum to maximum capacities until the wipers reach the rightmost position.
It is understood that the fuel injectors 14-1 to 14-4 are successively brought into operation and the overall fuel quantity delivered to the combustion chamber increases continuously with the rightward movement of the wipers and decreases continuously with the leftward movement of the wipers.
The movement of the wiper terminals 90 is made to correspond to the detected engine operating parameters with the electromechanical transducer 84. The control circuit 78 thus operates to provide stepwise operation of the injectors as well as continuous operation of each injector.
When all the injectors are operating at their full capacities, a variation of the potential at the accelerator electrodes of all the injectors will produces a simultaneous variation of fuel quantity ejected from each injector. It is thus possible to provide a coarse fuel quantity control by means of the control circuit 36 in response to a detected throttle position and then a fine control is effected by controlling the individual injectors in response to detected various engine operating parameters such as engine temperature, intake vacuum and engine RPM.
The foregoing description shows only exemplary embodiments of the invention. Each of the afore-mentioned voltage control circuits may also be constructed of all electronic circuit elements. The voltage applied to the control electrodes may be in digital form using a pulse width modulator which functions to generate an output pulse of which the duration is proportional to the input signal. | An electrostatic fuel injector includes a plurality of threadlike tubes for ejecting charged fuel, an accelerator electrode for accelerating the fuel and a control electrode for modulating the amount of fuel ejected. A method for controlling the fuel injector includes applying a control bias to the control electrode with respect to the accelerator electrode in response to an engine operating parameter so as to modulate the amount of fuel in proportion to engine load. A plurality of such fuel injectors is stepwisely operated in response to the engine operating parameter to provide a wide range of variations in fuel quantity. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. patent application Ser. No. 13/913,927, filed on Jun. 10, 2013. U.S. patent application Ser. No. 13/913,927 is a continuation of U.S. patent application Ser. No. 12/780,050, filed on May 14, 2010. U.S. patent application Ser. No. 12/780,050 is a continuation of U.S. patent application Ser. No. 11/249,662, filed on Oct. 12, 2005. U.S. patent application Ser. No. 11/249,662 claims priority from U.S. Provisional Patent Application No. 60/617,988, filed on Oct. 12, 2004. U.S. patent application Ser. No. 13/913,927, U.S. patent application Ser. No. 12/780,050, U.S. patent application Ser. No. 11/249,662, and U.S. Provisional Patent Application No. 60/617,988 are incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention is directed to a video surveillance system, and in particular, by way of example and not limitation, to a video surveillance system adapted to be mounted in a law enforcement vehicle for producing a permanent digital evidentiary record, on a multi-media disc, of a traffic stop or other event and incidents occurring after a suspect's vehicle has been stopped.
In law enforcement, a reliable witness that is incapable of perjury is needed to substantiate actions taken by a law enforcement officer and to protect the officer against false allegations by persons involved in an incident. An excellent witness of this type is a video recording of the incident, now widely used in traffic stops and criminal investigations, which can be reviewed after the incident and archived. By recording the incident first-hand as it actually happens, video recordings serve to eliminate conflicting individual interpretations of the incident and facilitate effective and efficient law enforcement.
Vehicle-mounted video cameras to make video records of an incident or scene external to the law enforcement vehicle are well known in the art. For example, U.S. Pat. No. 4,949,186 to Peterson discloses a vehicle-mounted system in which a video-cassette recorder is housed in a vault located in the trunk of a patrol car. U.S. Pat. No. 5,677,979 to Squicciarini et al discloses a video surveillance system which integrates the outputs of a video camera, a radar unit, a remote control, and a wireless microphone to produce a comprehensive video recording of an incident from beginning to the end. This system also uses a video cassette recorder to capture the incident on videotape. However, VHS and digital video tapes are bulky, requiring considerable space for storage, are susceptible to damage, and degrade over time. Additionally, the data on tapes may only be accessed sequentially.
SUMMARY OF THE INVENTION
A video-data chapter segmentation method includes monitoring for at least one external start trigger, and responsive to detection of at least one of the at least one external start trigger, creating a chapter start point at a point in the video data corresponding to a specified time preceding the at least one detected external start trigger. The method further includes initiating recording of the video data beginning at the point in the video data and monitoring for at least one stop trigger. The method still further includes responsive to detection of at least one of the at least one stop trigger, creating a chapter stop point at a point in the data corresponding to a specified time preceding the at least one detected stop trigger.
A video-data chapter segmentation computer system includes a processor and a memory. The memory includes software instructions adapted to enable the computer system to perform the steps of monitoring for at least one external start trigger, and responsive to detection of at least one of the at least one external start trigger, creating a chapter start point at a point in the video data corresponding to a specified time preceding the at least one detected external start trigger. The software instructions are further adapted to enable the computer system to perform the steps of initiating recording of the video data beginning at the point in the video data, monitoring for at least one stop trigger, and responsive to detection of at least one of the at least one stop trigger, creating a chapter stop point at a point in the data corresponding to a specified time preceding the at least one detected stop trigger.
A data-encoding system includes a source of unencoded data, and a first encoder interoperably coupled to the source, wherein the first encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a first data rate. The data encoding system further includes a second encoder interoperably coupled to the source, wherein the second encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a second data rate in which the second data rate exceeds the first data rate.
A data-encoding method includes a fast encoder interoperably coupled to a source of unencoded data receiving the unencoded data, encoding the unencoded data, and outputting encoded data at a first data rate. The method further includes a second encoder interoperably coupled to the source receiving the unencoded data, encoding the unencoded data, and outputting encoded data at a second data rate, wherein the second data rate exceeds the first data rate.
A data-overflow-handling method includes storing at least one of captured audio data, video data, and metadata to a first directory of a non-removable data storage medium, and determining whether an event is being recorded. The method further includes responsive to a determination that an event is being recorded, storing an image of the stored at least one of captured audio data, video data, and metadata to a second directory of the non-removable data storage medium. The method still further includes determining whether a predefined capacity threshold relative to a removable data storage medium has been exceeded, and responsive to a determination that the predefined capacity threshold has been exceeded, creating a third directory of the non-removable data storage medium. The method still further includes determining whether data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium, and responsive to a determination that data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium, storing any unstored data in the second directory to the removable data storage medium. The method further includes determining whether the second directory contains finalization files, and responsive to a determination that the second directory contains finalization files, finalizing the removable storage medium and providing a prompt to insert another removable storage medium. The method still further includes responsive to a determination that the second directory contains no finalization files, returning to the step of determining whether data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium.
A data-overflow-handling computer system includes a processor and a memory. The memory includes software instructions adapted to enable the computer system to perform the steps of storing at least one of captured audio data, video data, and metadata to a first directory of a non-removable data storage medium, determining whether an event is being recorded, and responsive to a determination that an event is being recorded, storing an image of the stored at least one of captured audio data, video data, and metadata to a second directory of the non-removable data storage medium. The memory further includes software instructions adapted to enable the computer system to perform the steps of determining whether a predefined capacity threshold relative to a removable data storage medium has been exceeded, and responsive to a determination that the predefined capacity threshold has been exceeded, creating a third directory of the non-removable data storage medium. The memory further includes software instructions adapted to enable the computer system to perform the steps of determining whether data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium, and responsive to a determination that data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium, storing any unstored data in the second directory to the removable data storage medium. The memory further includes software instructions adapted to enable the computer system to perform the steps of determining whether the second directory contains finalization files, and responsive to a determination that the second directory contains finalization files, finalizing the removable storage medium and providing a prompt to insert another removable storage medium. The memory still further includes software instructions adapted to enable the computer system to perform the step of responsive to a determination that the second directory contains no finalization files, returning to the step of determining whether data in the second directory of the non-removable storage medium has not been stored to the removable data storage medium.
A method for archiving data includes receiving data, storing the data on a first data storage medium, and selecting a portion of the data. The method further includes determining if at least one environmental factor indicates that environmental conditions are acceptable for storing the selected portion of the data on a second data storage medium. The method still further includes responsive to a determination that the at least one environmental factor indicates that environmental conditions are acceptable, storing the selected portion of the data on the second data storage medium.
A computer system for archiving data includes a processor and a memory. The memory includes software instructions adapted to enable the computer system to perform the steps of receiving data, storing the data on a first data storage medium, and selecting a portion of the data. The memory further software instructions adapted to enable the computer system to perform the steps of determining if at least one environmental factor indicates that environmental conditions are acceptable for storing the selected portion of the data on a second data storage medium, and responsive to a determination that the at least one environmental factor indicates that environmental conditions are acceptable, storing the selected portion of the data on the second data storage medium.
A data security method includes performing a checksum on data contained on a removable data storage medium, and storing the checksum on the removable data storage medium in at least one of an encrypted and a hidden form. The method further includes storing a unique serial number pertaining to the removable storage medium to the removable storage medium, and storing a checksum and a corresponding unique serial number of a plurality of previous removable storage media to the removable storage medium.
A data security computer system includes a processor and a memory. The memory includes software instructions adapted to enable the computer system to perform the steps of performing a checksum on data contained on a removable data storage medium, and storing the checksum on the removable data storage medium in at least one of an encrypted and a hidden form. The memory further includes software instructions adapted to enable the computer system to perform the steps of storing a unique serial number pertaining to the removable storage medium to the removable storage medium, and storing a checksum and a corresponding unique serial number of a plurality of previous removable storage media to the removable storage medium.
The above summary of the invention is not intended to represent each embodiment or every aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the method and apparatus of the present invention may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings wherein:
FIG. 1 is a block diagram of an in-vehicle system for recording video, audio, and data in accordance with principles of the present invention;
FIG. 2 is a procedure for opportunistic archiving without error checking in accordance with principles of the present invention;
FIG. 3 is a procedure for opportunistic archiving with optional error checking in accordance with principles of the present invention;
FIG. 4 is a procedure for automatic DVD-video chapter segmentation by external triggers in accordance with principles of the present invention;
FIG. 5 is a procedure for parallel high and low bit-rate encoding with post even bit rate selection in accordance with principles of the present invention;
FIG. 6 is a perspective and side view of an embodiment of a drive suspension system in accordance with principles of the present invention; and
FIG. 7 is a procedure for automatic DVD-video disc record overflow handling in accordance with principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 , a block diagram of an in-vehicle system for recording video, audio, and data in accordance with an embodiment of the present invention is illustrated. In the system of FIG. 1 , a first video decoder 10 a and a second video decoder 10 b each include a plurality of respective video inputs 15 a , 15 b for receiving analog video signals from one or more video sources, such as, for example, a video camera. In the embodiment of the present invention illustrated in FIG. 1 , each of the video decoder 10 a and 10 b receives analog video signals from a front video camera, a rear video camera, and an in-vehicle camera, although it should be understood that, in some embodiments, more or fewer cameras may be used. Each of the video decoders 10 a , 10 b processes the received video signals and produces respective digital video signals 20 a and 20 b . The digital video signals 20 a and 20 b are then provided to a video processor 25 . The video processor 25 processes the digital video signals 20 a and 20 b and outputs the processed video signals to a video bus 35 as a video stream.
In an exemplary embodiment of the present invention, the video processor 25 includes a video picture-over-picture (POP) field programmable gate array (FPGA) chip that processes video from one or more sources to combine the video from the multiple sources to be combined into a single video stream. For example, two video camera feeds can be processed by the video processor 25 for simultaneous display on the same screen as a split screen image. The system of FIG. 1 can be further provided with a frame memory 30 associated with the video processor 25 to store video frames during processing by the video processor 25 . The video stream from the video bus 35 is provided to first and second audio/video encoder integrated circuits (ICs) 40 a , 40 b . In accordance with principles of the present invention, the first and second video encoder ICs 40 a , 40 b include circuitry adapted to encode video and audio in compliance with a Motion Picture Expert Group (MPEG) standard, such as the MPEG-2 standard. For example the first and second video encoders 40 a , 40 b can be MPEG codec ICs. However, other video-encoding standards may be used without departing from principles of the invention.
The system of FIG. 1 also includes an audio analog-to-digital converter 45 adapted to receive analog audio signals 50 from one or more audio sources, such as microphones, and process the analog audio signals 50 to produce a digital audio signal 55 . In accordance with the embodiment of the present invention illustrated in FIG. 1 , an analog audio signal from a wireless microphone is provided to a left channel input of the audio analog-to-digital converter 45 , an analog audio signal from a cabin microphone is provided to a right channel of the audio analog-to-digital converter 45 , and the audio analog-to-digital converter 45 outputs a combined digital audio signal 55 therefrom.
The digital audio signal 55 is then provided to each of the first and second audio/video encoder ICs 40 a , 40 b . Each of the first and second audio/video encoder ICs 40 a, 40 b encodes the video stream received from the video bus 35 and the digital audio signal 55 from the audio analog-to-digital converter 45 as respective encoded audio/video streams 60 a and 60 b , such as, for example, MPEG-2 streams. In various embodiments of the present invention, the first audio/video encoder IC 40 a and the second audio/video encoder IC 40 b output representations of the same video and audio streams that have been encoded at different data rates in parallel. For example, in accordance with principles of the present invention, the first audio/video encoder IC 40 a outputs a high-bit-rate encoded stream 60 a (e.g., 6.0 Mbps), while the second audio/video encoder IC 40 b outputs a low-bit-rate encoded stream 60 b (e.g., 1.0 Mbps) representation of the same audio and video signals. The low-bit-rate stream can be obtained, for example, by reducing at least one of the video resolution and the frame rate. The system of FIG. 1 can be further provided with first and second coded memory 65 a , 65 b associated with each of the first and second audio/video encoder ICs 40 a , 40 b , respectively, for use by the full and second audio/video encoder ICs 40 a , 40 b as memory storage during encoding operations.
The resolution, bit-rate, and frame rate of both the low-bit-rate stream and the high-bit-rate stream can be set based on a record length selection made in a setup menu. Some example combinations are shown in Table 1:
TABLE 1
Resolution
Var. Bit rate
Frame Rate
Record Length
720 × 480
5-6 Mbps
30 fps
2 hrs
480 × 480
2.0 Mbps
30 fps
4 hrs
352 × 480
1.5 Mbps
30 fps
6 hrs
352 × 480
1.1 Mbps
30 fps
8 hrs
Each of the first encoded stream 60 a and the second encoded stream 60 b are then provided to a system FPGA 70 . The system FPGA 70 provides the first encoded stream 60 a and the second encoded stream 60 b over an IDE bus 75 to a hard drive 80 . The system of FIG. 1 can further include a buffer memory 90 associated with the system FPGA 70 to buffer data before it is written to the hard drive 80 . The first encoded stream 60 a and the second encoded stream 60 b are each buffered and written to the hard drive 80 . As a result, two versions of the same video and audio source, for example, a high-bit-rate encoded and a low-bit-rate encoded version, are buffered and written to the hard drive 80 for subsequent processing. After a predetermined time period has elapsed and/or after a particular event has occurred, the encoded video and audio data may be sent over the IDE bus 75 from the hard drive 80 to a DVD read/write (RW) drive 85 for archiving to a DVD disc. In accordance with an embodiment of the present invention, the encoded video and audio data is written to the DVD disc so that the DVD disc is formatted as a standard DVD video disc playable in a standalone (i.e., non-PC based) DVD player. The hard drive 80 is described as an example of a non-removable data storage medium such as typically found in personal computers. A DVD disc is described as an example of a removable data storage medium. Other examples of removable data storage media include floppy discs, and flash memory drives.
The system of FIG. 1 further includes a microcontroller 90 that functions to control the various components as well as the overall operation of the system of FIG. 1 . Flash memory 100 and dynamic RAM 105 may further be connected to the microcontroller 90 via a system bus 95 . The flash memory 100 may function to store firmware for use by the microcontroller 90 , and the dynamic RAM 105 may be used by the microcontroller 90 as temporary storage. In accordance with principles of the present invention, the firmware within the flash memory 100 can be upgraded, for example, by inserting a disc including updated firmware into the DVD RW drive 85 .
The microcontroller 90 is further provided with a data input 110 for receiving metadata including externally-measured data. Examples of metadata that can be provided to the data input 110 include Global Positioning System (GPS) coordinates, GPS calculated patrol speed, vehicle speed sensor (VSS) calculated patrol speed, radar measured patrol speed, radar target speed, accelerometer X, Y, and Z values, braking status, emergency lights status, siren status, system board temperature, drive door opening and closing logging, power up and power down logging, and DVD disc ejection and insertion logging. The metadata is provided by the microcontroller 90 to the system FPGA 70 , which further transmits the metadata to the hard drive 80 , where it is written to a metadata log file in association with the encoded audio and video data. Accordingly, a particular item of metadata can directly linked to the audio and video segment obtained at the time that the metadata item was measured.
In addition, a subset of the metadata is included in the encoded audio and video data so that it is available for viewing in parallel with the audio and video during playback. In accordance with an embodiment of the present invention, the subset of the metadata is included in one or more closed-captioning fields of an MPEG-2 encoded DVD disc. An advantage provided by including the subset of the metadata in a closed-captioning field is that the visibility of the metadata information can be selectively toggled by a viewer of the audio and video. Another advantage provided by including the subset of the metadata in a closed-captioning field is that the information in the closed-captioning field is a text overlay that does not effect the encoding of the underlying video; thus, the underlying video is not degraded by the inclusion of the metadata. Examples of metadata that may be included in the closed-captioning field include time, date, frame counter, vehicle ID, GPS longitude and latitude, vehicle speed (from VSS signal), radar target speed, radar patrol car speed, remote microphone active indicator, emergency lights active indicator, siren active indicator, braking in progress indicator, and camera ID and zoom level. In still another embodiment of the present invention, the subset of metadata may by provided in a subtitle field.
The system of FIG. 1 further allows for playback of encoded audio and video stored on the hard drive 80 and a disc in the DVD RW drive 85 . To accomplish playback, the system of FIG. 1 further includes a DVD decoder 115 that receives encoded audio and video from either the hard drive 80 or the DVD RW drive 85 via a playback bus. The DVD decoder 115 decodes the video into a video output signal 120 and decodes the audio into a digital audio signal 125 . The digital audio signal 125 is provided to a digital-to-audio converter 130 that converts the digital audio signal to an analog audio signal 135 . A DVD/on-screen display (OSD) memory 140 may further be provided for use by the DVD decoder 115 as temporary storage during decoding.
The system of FIG. 1 may also be provided with an Ethernet interface 145 that allows for communication between either a wired or wireless Ethernet-connected device and the microcontroller 90 . The Ethernet interface 145 may be used, for example, for transmitting encoded audio and video, as well as associated metadata, to a central office. The Ethernet port can also be used for uploading new firmware files, and for populating user settings as configured on a laptop computer attached to the invention. Specific identifiers shown in FIG. 1 for various components illustrated therein are for illustrative purposes. These identifiers will be understood by those having skill in the art to be merely examples of components that could be employed in the system shown therein. Other commercially available components could be employed without departing from the principles of the invention.
Event Based Recording
In various embodiments of the present invention, recording of video, audio, and metadata is event-based. In these embodiments, the system only records when a triggering event has occurred, for example, when the user turns on the emergency lights, siren, the onboard accelerometers sense a vehicle crash, or when the user manually hits a record button. Upon occurrence of the event, the beginning of a recorded event is marked. Other examples of an event that initiates recording can be, for example, a traffic stop, a chase, a domestic call, or pulling into a driveway. The recording of the event continues until a stop point is determined. In at least one embodiment of the present invention, the stop point is determined when the user hits a stop button. The system may also include an automatic stop event that allows the system to automatically stop recording at a predetermined time after all start record triggers have been tuned off (e.g., the lights and siren are off and the wireless microphone is off), but the user has forgotten to hit the stop button. If the system detects that that condition has occurred based on user settings, it can decide to enter a stop flag and stop recording the event.
In at least one embodiment of the present invention, when the system is turned on, two data streams (i.e., a high bit-rate stream and a low bit-rate stream) as well as metadata are recorded to the hard drive 80 . The metadata may include, for example, the status of the brake lights, status of the emergency lights and siren, GPS coordinates, the vehicle's speed, data from an interface from the police radar system, etc. The metadata and the high and low bit-rate streams are time-stamped and synchronized. During recording to a DVD disc, the video and/or audio of events, as well as the metadata are recorded to the DVD disc.
The system may also use vehicle speed as a recording trigger where the system can initiate the recording of an event if the patrol car exceeds a preset speed. For example, a department supervisor can decide that if an officer ever goes in excess of 110 miles an hour, the system should begin recording an event to the hard drive 80 or the DVD drive 85 . A new event begins automatically and the officer has no control over the recording of the event. Likewise, organizations outside of law enforcement may utilize threshold criteria for initiating self-activating monitoring of persons or conditions.
Opportunistic Archiving
The automobile environment is subject to demanding environmental conditions for the operation of electronic equipment. Recording onto a rewriteable DVD in an automobile environment is particularly subject to these conditions. A system in accordance with principles the present invention has a drive suspension system in place. The system monitors shock and vibration in x, y, and z axes using accelerometers. The system may also monitor the vehicle speed by one or more of three methods. The system can monitor vehicle speed through the VSS signal. If an optional GPS subsystem is included in the system, the system can get speed coordinates from the GPS data. If the system is interfaced to a radar system and the radar is operating in moving mode, the system can get vehicle speed from the radar. In various embodiments of the present invention, an opportunistic archiving algorithm is used that provides parameters and steering as to when the system should burn to the DVD drive 85 . Using shock and vibration measurements, the opportunistic archiving algorithm is adapted to ensure that data is not written to the DVD disc until environmental conditions are acceptable for doing so.
Referring now to FIG. 2 , a procedure for opportunistic archiving without error checking in accordance with principles of the present invention is illustrated. In step 205 , background recording of data including, for example, video data, and metadata, is initiated. In background recording, an encoded stream, and optionally associated metadata, is continuously written to the hard drive 80 . Thus, referring again to FIGS. 1 and 2 , during background recording, the first encoded stream 60 a and the second encoded stream 60 b , and optionally associated metadata, are continuously written to the hard drive 80 . Background recording of audio, video, and metadata is typically performed in one minute segments, although it should be understood that other segment lengths may be used. After initiation of background recording (step 205 ), the data is buffered in RAM (step 210 ) and then written to the hard drive 80 (step 215 ). A determination is then made regarding whether any record triggers are active (step 217 ). If a determination is made that no record triggers exist (step 220 ), background recording is continued (step 225 ) and the procedure returns to step 205 .
If a determination is made that a record trigger is active (step 230 ), the data to be archived on the DVD is selected (step 235 ). The range of data to be archived includes selected time periods before and after event start and stop points. For example, the system can be configured to archive a range of data that extends from ten minutes prior to the start point and ten minutes after the stop point. At step 240 , a verification of environmental factors is performed to insure that environmental conditions are acceptable for recording data to the DVD disc. The environmental factors can include, for example, temperature, shock, and vibration measurements. If the environmental factors are determined to exceed DVD drive limits (step 245 ), better environmental conditions are waited for via use of, for example, a timer (step 250 ), and the procedure returns to step 240 . Steps 240 - 255 can be characterized collectively as opportunistic-archiving steps.
If the environmental factors are determined to be within predetermined limits (step 255 ), burning of a sector of data to the DVD disc is initiated (step 260 ). During the burn cycle, accelerometers are monitored to determine whether any G-spikes exceed tolerable limits (step 265 ). An example of a tolerable limit for burning of data to a DVD is less than 0.3 G. If it is determined that a G-spike occurred during the burn cycle that is above tolerable limits (step 270 ), a decision is made to rewrite the sector in question (step 275 ) and the procedure returns to step 260 . If it is determined that no G-spikes occurred during the burn cycle that are above the tolerable limits (step 280 ), the procedure continues to the next sector to be burned (step 285 ) and then returns to step 205 . Steps 260 - 285 can be characterized collectively as reactive correction steps.
Referring now to FIG. 3 , a procedure for opportunistic archiving with optional error checking in accordance with principles of the present invention is illustrated. In step 305 , background recording of data including, for example, audio data, video data, and metadata, is initiated. In background recording, an encoded stream, and optionally associated metadata, is continuously written to the hard drive 80 . Thus, referring again to FIGS. 1 and 3 , during background recording, the first encoded stream 60 a and the second encoded stream 60 b , and optionally associated metadata, are continuously written to the hard drive 80 . Background recording of audio data, video data, and metadata is typically performed in one minute segments, although it should be understood that other segment lengths may be used. After initiation of background recording (step 305 ), the data is buffered in RAM (step 310 ) and then written to the bard drive 80 (step 315 ). A determination is then made regarding whether any record triggers are active (step 317 ). If a determination is made that no active record triggers exist (step 320 ), background recording is continued (step 325 ) and the procedure returns to step 305 .
If a determination is made that a record trigger is active (step 330 ), the data to be archived on the DVD is selected (step 335 ). The range of data to be archived includes selected time periods before and after event start and stop point. For example, the system can be configured to archive a range of data that extends from ten minutes prior to the start point and ten minutes after the stop point. At step 340 , a verification of environmental factors is performed in order to insure that environmental conditions are acceptable for recording data to the DVD disc. The environmental factors can include, for example, temperature, shock, and vibration measurements. If the environmental factors are determined to exceed DVD drive limits (step 345 ), better environmental conditions are waited for via use of, for example, a timer (step 350 ), and the procedure returns to step 340 . Steps 340 - 355 can be characterized collectively as opportunistic archiving steps.
If the environmental factors are determined to be within predetermined limits (step 355 ), burning a sector of data to the DVD disc is initiated (step 360 ). At step 365 , a checksum is calculate for the sector from hard drive data. The burned sector is then read from the DVD disc (step 370 ), and a checksum is calculated from the sector read from the DVD (step 375 ). The checksum obtained from hard drive data and the checksum obtained from the burned DVD sector are compared and, if the checksums do not match, the sector is rewritten (step 380 ) and the procedure returns to step 360 . If the checksums match, the archiving procedure returns to step 305 . Steps 360 - 385 can be characterized collectively as DVD burn error correction steps.
In various embodiments, an opportunistic archiving algorithm may be used that also considers, in addition to environmental factors, how much data the system needs to archive to the DVD disc. For example, if the system starts off in the morning and there have been no events and no start flags, the system is operating with zero unburned events. However, if, for example, the user gets into a high-speed chase that lasts for three hours and the system has not detected a stop trigger, the system has recorded three hours of unburned data to the hard drive 80 . In this situation, the system could lower the environmental limits, at step 255 or 355 for example, in order to archive the large amount of accumulated data to the DVD disc. Environmental conditions, including a speed factor, may also be considered. The system may consider whether the vehicle is driving along at a high rate of speed (e.g., hundred miles an hour) or if it is stopped. The algorithm may also consider accumulated shock and vibration.
The algorithm processing starts with the calculation of how much data is present and comes up with a numerical value. And then the processor using the algorithm comes up with a numerical value for how conducive the environment is to DVD burning. The processor using the algorithm subtracts the environment number from the unburned data number and comes up with a value. If the value is positive, the need to burn data is greater than how bad the environmental conditions are. If the algorithm defines a negative number, the unburned data does not outweigh how bad the environmental conditions are.
If the environmental conditions are very poor, the system does not record anything. Instead, the system just waits and monitors for a while and checks the environmental conditions again. If the speed factor is zero (i.e., the car is stopped), that is preferably an automatic burn decision. Condition one is no speed, which is preferably an automatic decision to burn anything on the hard drive 80 that needs to be burned. Condition number two is unacceptable environmental conditions under which the system does not burn anything. Condition number three is somewhere in between, in which the system has some unburned event data, the car is moving, and determinations are made regarding how bad the conditions are, how much does the need to burn data outweigh the environmental conditions that the system detects.
The hard drive 80 of the system preferably has a accelerometer to detect physical shocks. When the hard drive 80 detects an unacceptable shock, the system goes back and recopies the last section. An error is assumed, so the last DVD section is overwritten. The hard drive 80 may be mounted on a vibration shock mount as well. In various embodiments, the DVD drive 85 can also include an accelerometer to detect physical shocks. Hard drives typically have a 200 g shock tolerance whereas DVD drives typically have a 0.5 g shock tolerance.
An illustrative opportunistic archiving algorithm could utilize the following equation:
(Buffer Amount)−[(Speed Factor)+(Shock Factor)+(Vibration Factor)]=Archive Threshold
where
Buffer Amount=Size of Data Buffer
Speed Factor=Accumulated Vehicle Speed From Recent History
Shock Factor=Peak Shock in Recent History
Vibration Factor=Accumulated Vibration From Recent History
If the Archive Threshold is exceeded, the need to burn data overrides the environmental conditions. If the Archive Threshold is not exceeded, the amount of unburned data does not override the environmental conditions.
Automatic Chapter Segmentation by Event Markers
In various embodiments of the present invention, the system may be adapted to automatically divide the video into separate navigable chapters to make location of a specific point or event easier during playback, such that each chapter of the DVD disc contains the data from one event. This process eliminates the need to fast forward or rewind the media to search for a specific traffic stop or event. The start of an event period is determined by monitoring metadata from various devices, such as external emergency lights, emergency siren, wireless microphone activation, extreme shock data from accelerometers indicating, for example, a collision or panic braking, an elapsed time period, etc. The start of an event period can also be determined by an operator pressing a RECORD key on a control panel.
The end of an event is determined by the operator pressing a STOP key on the control panel or by the passage of a predetermined period of time after any triggering device is turned off or is inactive. In various embodiments, when the system is turned on, all video data, audio data, and metadata is continuously written to the hard drive 80 , and only event data is written to the DVD disc. The system is able to automatically include video and audio data that occurred prior to the start of the event period or after the end of an event period by moving event start and end flags based on rules determined by user settings. For example, a setting in a user-interface menu can be used to determine how much data to include in the DVD chapter before and after the event markers.
Referring now to FIG. 4 , a procedure for automatic DVD-video chapter segmentation by external triggers is illustrated. In step 405 , background recording of data including audio, video, and metadata is initiated. In various embodiments of the present invention, background recording of audio, video, and metadata is performed in one-minute segments, although it should be understood that other segment lengths may be used. At step 410 , external record triggers are monitored for the occurrence of one or more triggering events. If a record trigger is not detected (step 415 ), the procedure returns to step 405 .
If a record trigger is detected (step 420 ), a new chapter start point is initiated (step 425 ) that includes a specified number of minutes of data from before the event start point to the beginning of the chapter. At step 430 , burning of the data from the event period to the DVD is started. At step 435 , monitoring of stop triggers is performed. The stop triggers may be either generated by a timer or user-initiated. If a stop trigger is not detected (step 440 ), event recording is continued (step 445 ), and the procedure returns to step 430 . If a stop trigger is detected (step 450 ), a chapter stop point is determined, which step includes a specified number of minutes of data from after the event stop point being added to the end of the chapter (step 455 ). Next, the DVD chapter menu is built (step 460 ), a video frame from the event is selected for use as a selectable chapter icon (step 465 ), and a time/date stamp from the chapter stop point is used as part of the chapter name/number (step 470 ). Next, the DVD chapter is closed out (step 475 ), and the procedure returns to step 405 .
Parallel High and Low Bit-Rate Encoding
In order to provide users with the ability to archive as many hours of video and audio data on to a single DVD disc, while still providing maximum video quality for important events, various embodiments of the present invention provide for encoding multiple versions of the same video and audio source in parallel. The system encodes both a high bit-rate stream and a lower bit-rate stream. Both streams are buffered and written to the hard drive 80 .
The rules for archiving event data to the DVD disc can be determined by user settings. During typical operation, the system will automatically transfer the lower bit-rate video stream to the DVD disc based on event markers. Should the system capture some video or audio footage that the user deems to be important, the user can transfer the high bit-rate version to the DVD disc from data on the hard drive 80 . This process allows users to make extended-length recordings without having to sacrifice audio and video quality of important events.
A user may choose high or low quality video after an event has occurred. The system by default archives events to the DVD that are low quality. After the recording has been made, if something that was important has occurred, the user can easily go back and set new start and stop flags. A section of video may be chosen, whether it was included in the original event or not, a new chapter added to the DVD, and a high resolution version of the video can be chosen to be burned to DVD. After the fact, a user can choose to grab any video from the hard drive 80 and make new chapters on the DVD. The new chapters can be based on the same event or on multiple events or non-events, and then a user could choose high or low resolution.
Referring now to FIG. 5 , a procedure for high and low bit-rate encoding with post-event bit-rate selection in accordance with principles of the present invention is illustrated. In various embodiments of the present invention, the high and low bit-rate encoding occurs in parallel. At step 505 , a raw video stream, such as a BT656 stream, is split into first and second streams that are identical to each other. The first stream is provided to a first video encoder 40 a , which encodes the stream at a low bit-rate to be used for normal recording (step 510 ). The low bit-rate stream can be optionally written to a temporary storage area, such as a hard drive 80 , Flash RAM, RAM, or other storage media (step 515 ). The second stream is provided to a second video encoder 40 b , which encodes the stream at a high bit rate to be used as a backup for important events (step 520 ). The data of the high bit-rate stream is then written to a circular buffer (step 525 ), which is a continuously-overwritten data buffer on a hard drive 80 , Flash RAM, RAM, or other storage media. If no important events occur while the high bit-rate data is in the circular buffer (step 530 ), new high bit-rate data overwrites old data in the circular buffer (step 535 ).
If an operator deems a time period from the data buffer to be important (step 540 ), the system takes the high-bit-rate data from the important time period (step 545 ) selected by the operator. At step 550 , the low-bit-rate data and the selected portion of the high-bit-rate data are written to storage media, such as a DVD disc, hard drive, flash memory, etc. (step 550 ). In various embodiments, the step 550 of writing the low-bit-rate data to the storage media can include opportunistic archiving such as that described with respect to FIG. 2 and FIG. 3 . In various embodiment of the present invention, step 515 of writing the low-bit-rate stream to a temporary storage can be omitted, and the low-bit-rate stream can be written directly to the storage media in step 550 . In other embodiments of the present invention, the temporary storage for the low-bit-rate data and the circular buffer for the high-bit-rate data are the same hard drive, and the storage media for the low-bit-rate data and the selected portion of the high-bit-rate data are a DVD disc.
Record After-The-Fact
Recording after-the-fact permits manual chapter event creation to be performed. If a user wants to go in after the fact and copy some video that wasn't marked as an event, the user can go back and manually put in a new start and stop point. The system will automatically grab that section of video and feed it to the DVD drive 85 and make a new chapter. The common use of that feature will be by, for example, internal affairs in order to investigate some alleged misconduct. Of course, embodiments of the system may be applied to areas outside of the area of law enforcement, and then the conduct referred to may be an officer or another party in an organization utilizing the methods and systems of the present invention.
Drive Suspension System
A drive suspension system in accordance with principles of the present invention permits isolation of the DVD drive from environmental conditions that could impair DVD burning. Different suspension systems may be used in different versions of the system. One version of the system as currently envisioned is entirely overhead-console mounted. Another version of the system is a multipiece unit (e.g., two) that may be used when there is not room to mount the overhead console-mounted version. In the second version, the user can, for example, put the recording unit underneath the seat and the display and control panel on a stalk near the radio console area. Although packaging for the drive suspension system is different on the two versions discussed, the underlying principles are analogous and other versions are possible without departing from principles of the present invention.
Referring now to FIG. 6 , a perspective and side elevational view of an embodiment of a drive suspension system in accordance with an embodiment of the present invention are illustrated. In FIG. 6 , a DVD recorder drive 605 slides into a drive chassis 610 . The drive suspension system includes a momentum mass in the form of a heavy steel chassis weight 615 . The assembly including the DVD recorder drive 605 , the drive chassis 610 , and the chassis weight 615 is suspended inside an assembly shield area 620 by expansion elements, such as, for example, assembly springs 625 . On the chassis 610 , four pins 635 insert into four vibrational-energy-absorption elements, such as, for example, silicon-oil-filled sack dampers 630 . A hole inside the particular damper shown in FIG. 6 is provided for the pins 635 from the chassis 610 to meet into. The four silicon-oil-filled sack dampers 630 serve to stabilize the floating mechanism, provide heavy damping characteristics, and reduce the resonance frequency. The chassis weight 615 provides momentum and also serves to help reduce the resonance frequency. In a typical embodiment, there is about one-half inch of suspension travel in every direction.
In the under-seat version of the system, a spring orientation pivot 640 is used to permit horizontal mounting or vertical mounting (e.g., on the side of a cage) or mounting on a stalk or on a center console. If the system is mounted flat, the springs are mounted in an upward orientation. However, if the user turns the orientation such that the drive is pointing upward and gravity is trying to pull the drive in a different direction, the spring may be pivoted so that the spring is able to handle the gravity load in that direction.
Automatic DVD-Video Disc Record Overflow Handling
Various embodiments of the invention provide a method to seamlessly allow a user to record data onto the DVD disc to the disc's capacity, yet continue to capture and prepare additional data intended to be burned onto another DVD disc. With previous in-vehicle recording systems, there was a risk of running out of media (e.g., DVD) space during the middle of a patrol officer's shift. Since the media is considered evidentiary in nature, many law enforcement agencies limit access to the media, and do not provide the officer with a second piece of media. Thus, when the media became full, it would necessitate a trip back to the police station to replace the media with blank media. Automatic DVD-Video disc record overflow handling in accordance with principles of the invention serves to eliminate the need for an officer to return to the police station to replace media during a shift. The officer may continue recording even after the DVD media is at capacity. In a typical case, the system finalizes a first DVD and automatically prepares unburned data for an additional DVD. When new media (e.g., DVD) is inserted into the drive, the unburned data is automatically transferred onto the new media.
Referring now to FIG. 7 , a procedure for automatic DVD-video disc record overflow handling is illustrated. At step 705 , video, audio, and data from vehicle mounted cameras, microphones, and sensors is captured. At step 710 , video, audio, and data is continuously written onto a hard drive 80 . Next, a determination is made regarding whether the system is in event-record mode (step 715 ). If the system is not in event-record mode, the procedure (step 720 ) returns to step 705 . Steps 705 - 720 can be characterized collectively as a data-capture process.
If it is determined that the system is in event-record mode (step 725 ), the procedure continues to step 730 , at which step data is written into a DVD image working directory on the hard drive 80 . At step 735 , a determination is made regarding whether the working directory is close to reaching the size limit of the DVD disc. If it is determined that the working directory is not close to reaching the size limit of the DVD disc (step 740 ), the procedure returns to step 715 . If it is determined that the working directory is close to reaching the size limit of the DVD disc, a DVD chapter-stop point is initiated and a DVD chapter menu is built (step 745 ). Next, all remaining files for the DVD-video image are closed out (step 750 ), the current working directory is saved (step 755 ), and a new working directory is created (step 760 ). The procedure then returns to step 715 . Steps 730 - 760 can be characterized collectively as DVD image preparation steps.
From step 730 , an execution proceeds also to step 765 . At step 765 , un-burned data in the working directory is looked for. Next, a determination is made regarding whether there is un-burned data in the working directory (step 770 ). If there is no un-burned data in the working directory (step 775 ), the process returns to step 765 . If there is unburned data in the working directory, DVD-video data from the working directory is transferred on to the DVD-video disc (step 780 ). At step 785 , a determination is made regarding whether the working directory contains finalized files. If the working directory does not contain finalized files (step 787 ), the procedure returns to step 765 . If the working directory contains finalized files, the DVD is finalized (step 790 ). At step 795 , the user is prompted to replace the current DVD with a blank DVD. At step 796 , a determination is made regarding if the user has loaded a blank DVD. If the user has not loaded a blank DVD (step 797 ), the procedure returns to step 795 . If the user has loaded a blank DVD, a check is made for a new DVD working directory (step 798 ). The procedure then returns to step 765 . Steps 765 - 798 can be characterized collectively as DVD burning process steps.
Automatic DVD Disc-Image Back-Up
In various embodiments, the system's hard drive 80 is formatted with a separate partition that is reserved for making mirror images of DVD discs. A typical DVD RW disc is 4.7 GB. As the system is creating a DVD disc, the system makes an exact duplicate of the entire disc on the hard drive 80 in a separate partition. An administrator or user can select how many back-up copies of DVDs the system retains.
As the user continues to create new DVDs, the oldest hard-drive backup will be overwritten; thus, if the user selected three back-up images, by the time the user creates the fourth DVD, the oldest one is being overwritten with a mirror image of the number four disc. Using this feature, if an original DVD is lost, unreadable, or intentionally destroyed, a supervisor can go back and create an exact copy of the same DVD disc.
Video Data Security
Since the system's video files are typically in MPEG-2 format, the files could conceivably be manipulated using video-editing tools. In litigation, attorneys could attempt bring into question the authenticity of the MPEG files, suggesting that they could be exported, manipulated, and then re-inserted onto the disc. The system thus uses checksums in some embodiments to ensure that the files have not been manipulated or edited.
First Level of Security—The Self-Verifying Checksum Result
When the system is ready to close a DVD disc (e.g., just prior to disc ejection), the system performs a checksum calculation on the disc contents and writes that result into a hidden and/or encrypted file saved on the DVD disc. By using a video utility, the DVD disc can be analyzed to see if a checksum result from the discs contents matches the result of the bidden (and/or encrypted) checksum result on that DVD disc. This process verifies that the disc content matches the checksum file.
Second Level of Security—System Verification of the Hidden (or Encrypted) Checksum Files
The system also provides a method to verify that the checksum file that is hidden on a DVD disc has not been recreated to match a manipulated disc. This is done by comparing subsequently-recorded DVD discs (e.g., discs recorded using the same system) to the DVD disc in question. The system automatically generates a unique disc serial number for each DVD disc it records. This serial number is written onto the DVD disc and is also saved into a log file in the systems non-volatile memory. When a DVD disc is closed, the checksum result of that DVD disc is also written to the log file in the system's non-volatile memory.
The log file preferably contains the serial number and checksum result of every DVD disc that that specific system has authored. The entire contents of the log files that are stored on the system's non-volatile memory may then be copied onto every DVD disc the system creates. Every DVD disc created by a specific system can be used to verify the validity of a checksum result contained on any other DVD disc previously recorded by the same system.
Covert Recording Mode
In various embodiments of the present invention, the system has the ability to be placed into a covert-recording mode. In this mode, the system has the appearance of being powered off. However, it is actually recording data, such as video and audio, on the hard drive 80 . The covert-recording mode permits events inside a patrol car to be recorded without a suspect being aware that he is being recorded. A record trigger is generated when the system is placed into covert-recording mode. However, the system will only archive to the DVD after the system has been taken out of covert recording mode to prevent the DVD drive noise from giving an indication that the system is not actually powered off.
In an illustrative example of placing the system into covert recording mode, a user presses and holds a power OFF key for more than 2 seconds. A sound indicates that the unit has been placed into covert recording mode and all lights, backlights, indicators, and displays are turned off. This gives the appearance to a back-seat occupant that the unit is turned off. The system automatically selects an interior camera input to be recorded. The covert mode is ended by pressing POWER ON or a STOP key. At that time, the system lights, backlights, indicators, and displays are turned on, and the video that has been marked for recording will be archived to the DVD disc.
Various embodiments of the invention may reside in a computer system. Here, the term “computer system” is to be understood to include at least a memory and a processor. In general, the memory will store, at one time or another, at least portions of an executable program code, and the processor will execute one or more of the instructions included in that executable program code. It will be appreciated that the term “executable program code” and the term “software” mean substantially the same thing for the purposes of this description. It is not necessary to the practice of this invention that the memory and the processor be physically located in the same place. That is to say, it is foreseen that the processor and the memory might be in different physical pieces of equipment or even in geographically distinct locations.
Various embodiments of the invention may also be embodied in a computer program product, as will now be explained. On a practical level, the software that enables the computer system to perform the operations described further below in detail, may be supplied on any one of a variety of media. Furthermore, the actual implementation of the approach and operations of the invention are actually statement written in a programming language. Such programming language statements, when executed by a computer, cause the computer to act in accordance with the particular content of the statements. Furthermore, the software that enables a computer system to act in accordance with the invention may be provided in any number of forms including, but not limited to, original source code, assembly code, object code, machine language, compressed or encrypted versions of the foregoing, and any and all equivalents.
One of skill in the art will appreciate that “media”, or “computer-readable media”, as used here, may include a diskette, a tape, a compact disc, an integrated circuit, a ROM, a CD, a cartridge, a remote transmission via a communications circuit, or any other similar medium usable by computers. For example, to supply software for enabling a computer system to operate in accordance with the invention, the supplier might provide a diskette or might transmit the software in some form via satellite transmission, via a direct telephone link, or via the Internet. Thus, the term, “computer readable medium” is intended to include all of the foregoing and any other medium by which software may be provided to a computer.
Although the enabling software might be “written on” a diskette, “stored in” an integrated circuit, or “carried over” a communications circuit, it will be appreciated that, for the purposes of this application, the computer usable medium will be referred to as “bearing” the software. Thus, the term “bearing” is intended to encompass the above and all equivalent ways in which software may be associated with a computer usable medium.
For the sake of simplicity, therefore, the term “program product” is thus used to refer to a computer usable medium, as defined above, which bears in any form of software to enable a computer system to operate according to the above-identified invention. Thus, the invention may also be embodied in a program product bearing software that enables a computer to perform management of information according to the invention.
In the foregoing Detailed Description, it can be seen that various features may be grouped together into a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiment(s) of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all the features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment of the invention. | A data-coding system includes a source of unencoded data, and a first encoder interoperably coupled to the source, wherein the first encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a first data rate. The data encoding system further includes a second encoder interoperably coupled to the source, wherein the second encoder is adapted to receive the unencoded data, encode the unencoded data, and output encoded data at a second data rate in which the second data rate exceeds the first data rate. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b). | 6 |
TECHNICAL FIELD
[0001] The field of this invention relates to trim molding for housing construction and a system for supporting a tight joint between trim members.
BACKGROUND OF THE DISCLOSURE
[0002] One important aspect for making new housing construction or a remodeling project appear well built and add value to a home, condo or other building is the trim molding. Trim molding may be placed about various places within a building including door and window frames as well as around upper edges between walls and ceilings. Other decorative trim moldings such as chair moldings also dress a building to be attractive.
[0003] Often trim molding is made from a plurality of separate trim members that are connected together at a tight joint to form a continuous looking unitary member. The trim can often be shellacked, or painted to further hide and conceal the joint. A poorly installed trim molding that forms a gap within the joint is detractive and undesirable.
[0004] A problem with many installed trim moldings is that while they are often assembled correctly with tight joints that is either invisible or barely noticeable, after the elapse of time, settling of the new underlying construction will often pull apart the joint and form a crack in the paint coating or otherwise make the make the joint noticeably visible with a large unsightly gap. Older settled buildings often have quite large and noticeably unsightly gaps between trim members. While extra nails and screws can secure a joint, the nails and screws are either undesirably exposed or require wood putty to conceal them. The extra wood putty is also undesirable because it does not take stain well or it dries up and pops out.
[0005] The settling and gapping of the trim joint is exacerbated by the common interposition of drywall between the trim member and a supporting stud member or the like. Drywall is not a structural support member. Thus, the spacing of the trim member from the supporting stud member due to the interposition of drywall reduces the lateral rigidity provided by the nail. In other words, the long extension of the nail from the trim member through the drywall and to the stud member reduces the lateral rigidity provided by the nail.
[0006] What is needed is a concealed trim molding system that retains tight trim joints together and resists separation of the trim members. What is also needed is a system that secures the trim members together on the exterior side of any drywall.
SUMMARY OF THE DISCLOSURE
[0007] In accordance with one aspect of the invention, a joint reinforcement system mounts two trim members together to a supporting substrate. The joint reinforcement system includes a substrate and a reinforcement member being mounted to the substrate. Two trim members are mounted to abut each other to form a joint with each trim member positioned over a portion of the reinforcement member. The trim members are preferably adheredly mounted to the reinforcement member. A respective fastener pierces the respective trim members and extends through the reinforcement member and engages the substrate.
[0008] Often a layer of drywall may be interposed between the substrate and the reinforcement member. The reinforcement member is at the exterior side of any drywall and is in close proximity of the trim member. Preferably, the reinforcement member is mesh like with a plurality of perforations therethrough.
[0009] The reinforcement member may be made from metal. Preferably, the reinforcement member can be made from an aluminum sheet. The reinforcement member may have a substantially planar section.
[0010] Alternatively, the reinforcement member is bent with two substantially transverse planar sections to have trim members positioned substantially at right angles with respect to each other and secured to the respective transverse planar sections. The trim members may be a side trim member and upper trim member for a door or window opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Reference now is made to the accompanying drawings in which:
[0012] FIG. 1 is a front plan fragmentary view of an assembled trim assembly according to one embodiment of the invention;
[0013] FIG. 2 is an exploded view of the trim assembly shown in FIG. 1 ;
[0014] FIG. 3 is a fragmentary view similar to FIG. 1 with a trim member partially broken away to expose a portion of the reinforcement member;
[0015] FIG. 4 is a cross section view taken along lines 4 - 4 shown in FIG. 1 ;
[0016] FIG. 5 is view of another embodiment of the invention showing an exploded view of installation of interior trim molding for example for covering a window jamb.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring now to FIGS. 1-4 , a trim molding assembly 10 has two trim members 12 and 14 connected to a reinforcement member 16 which are all connected to a substrate, for example drywall 18 and other structural underlying members such as a stud 20 or jamb 21 (as shown in FIG. 4 ). Each trim member 12 and 14 are appropriately cut to provide a tight joint 22 . The reinforcement member 16 is positioned or the exterior side of the drywall 18 to span under both trim members 12 and 14 . By “exterior side”, it is meant the side that is opposite from the one facing the interior hidden section of wall. The shape of the reinforcement member 16 can be varied depending on the configuration of the trim molding. A typical shape can be a planar L-shape for trim members 12 and 14 that are abutted to each other at the top and side of a typical door or window opening 19 .
[0018] The reinforcement member 16 is a thin member that has rigidity against stretching along its main plane. In one preferred embodiment, it is foreseen that the member 16 can be made from a sheet of perforated aluminum that may have a thickness ranging from 1/64 to 1/32 to provide the sufficient rigidity but still allow a nail to be hammered therethrough by manual force. The sheet can be perforated with a plurality of apertures 30 . The apertures 30 may have a size for example to receive a finishing nail 32 . As shown more clearly in FIGS. 2 and 4 , the reinforcement member 16 has two bent corner tabs 24 that are bent substantially perpendicular to the main planar section 25 for tacking into dry wall 18 .
[0019] Installation of the trim joint 22 begins with tacking the corner tabs 24 of the reinforcement member 16 into the exterior side of dry wall 18 at positions 26 indicated in FIG. 2 . The member 16 has its main planar section 25 abut against the dry wall 18 . A layer of glue 33 suitable for wood and aluminum is then applied to the backside of each trim member 12 and 14 and the trim members are then pressed onto the reinforcement member 16 . As the trim member is pressed onto the reinforcement member, the glue makes contact with the planar outer face 27 of the reinforcement member 16 as well as intruding into the apertures 30 . A finishing nail 28 is then driven through a respective trim member 12 , 14 , the reinforcement member 16 , the dry wall 18 , and the underlying stud 20 or jamb 21 as shown in FIG. 4 .
[0020] After the glue sets with the set glue in the apertures 30 and bonding the reinforcement member 16 to each trim member 12 and 14 , the set joint 22 becomes resistant against relative movement in any direction that may cause separation of the trim members 12 and 14 . Caulk may then be conventionally applied to the inner and outer edges 29 between the trim members 12 and 14 and the dry wall 18 to conceal any gap 31 as shown in FIG. 4 and conceal the reinforcement member 16 . By having many apertures, the surface available for adhesion is greatly increased.
[0021] Another embodiment is shown in FIG. 5 where the reinforcement member 116 has two planar sections 40 and 42 that are substantially perpendicular to each other. The planar sections 40 and 42 each have one bent corner tab 24 being substantially perpendicular thereto. The corner tabs 24 are used to tack onto the jambs 120 and 121 where planar section 40 substantially abuts side jamb 120 and planar section 42 abuts header jamb member 121 . Trim members 112 and 114 then have their back sides glued and pressed against the respective planar sections 40 and 42 . Finishing nails 28 are then hammered in place to pierce respective trim members 112 , 114 , planar section 40 and 42 and jambs 120 and 121 . The completed and formed joint 122 will remain tight and resistant to gapping after the glue is cured.
[0022] The substrate member may have other shapes for custom trim installations. It can also be used for base trim members to prevent pull down of the base relative to side trim members or between two base trim members for wide door entrances where two base trim members are used.
[0023] The reinforcement member 16 and 116 by being in close proximity to the trim members and being positioned on the exterior side of the drywall in proximity to the trim members adds lateral rigidity to the trim member. Furthermore, the large area of adhesion provided by the mark planar reinforcement member provides strong support against any direction perpendicular to lateral motion. Thus, an improved joint resistant against relative movement in any direction is provided. The retention of this tight joint is particularly advantageous if the joint is painted or shellacked. The paint or shellac after it is applied and dried has a greater chance of not cracking which is common at conventionally constructed joints.
[0024] Other variations and modifications are possible without departing from the scope and spirit of the present invention as defined by the appended claims. | A joint support system for trim members 12 and 14 has a reinforcement member 16 attached to the trim members 12 and 14. A fastener fastens the trim members 12 and 14 to the reinforcement. An adhering glue may be applied and set between the reinforcement member 16 and trim members 12 and 14 to form a tight joint. | 4 |
FIELD OF THE INVENTION
This invention relates to a card connector for use in electric and electronic appliances in instruments and for use in printers and card readers, and more particularly to a card connector adapted to accommodate a plurality of cards by means of the same contacts.
BACKGROUND OF THE INVENTION
There have been many different kinds of cards as media for a wide variety of information. It has been a common practice to acquire or store various information from or onto a card inserted into a card connector connected to an information appliance.
In prior art card connectors, contacts are arranged correspondingly to cards which are able to be inserted into the card connector, respectively, in one-to-one relationship, and the contacts each at least comprise a contact portion adapted to contact the card, a holding portion held in a housing, and a connection portion to be connected to a substrate. Such card connectors are disclosed in the following Patent Literature 1 (Japanese Patent Application Opened No. 2003-31,861) and Patent Literature 2 (Japanese Patent Application No. 2004-161,293).
Patent Literature 1
According to the Abstract of the Japanese Patent Application Opened No. 2003-31,861, this invention has an object to provide a card connector for integrated circuit (IC) cards having a push-in and push-out mechanism common to plural kinds of cards to achieve the miniaturization in overall shape of the connector. In a card connector for IC cards including a housing having an inserting opening common to plural kinds of IC cards, into which an IC card is inserted to bring the electrode of the IC card into connection with the contacts in the inserting opening, the housing includes therein a slider adapted to advance or retract in conjunction with push-in and push-out operations of the IC card in the housing, and a locking mechanism for locking the slider and the IC card when the push-in is effected and for releasing the locking when the push-out is effected, whereby a shape and a position are set in the slider depending upon the width, length and front shape of the IC card, positions of electrodes of the IC card, and positions of the contacts relative to the housing, thereby enabling the slider to engage the IC card in compliance with shapes of the plural kinds of IC cards. FIGS. 1 and 2 of the Patent Literature 1 illustrate contacts each corresponding to respective card in one-to-one relationship.
Patent Literature 2
According to the Abstract of the Japanese Patent Application No. 2004-161,293 filed by the applicant of the present case, the invention has an object to provide a card connector which, after one card has been inserted, is capable of preventing a further card from being inserted and easy to design its housing and easy to remove a card and achieves its miniaturization without any limitation in circuit design of substrates and without any obstruction to the high density of conductors. In a card connector including a required number of contacts adapted to contact connection portions of a plurality of memory cards and a housing having a plurality of inserting openings for receiving a plurality of memory cards, respectively, and arranging and holding the contacts therein, the card connector comprises at least one locking member located at a predetermined position on the housing and pivotable or movable when one kind of card is inserted, and at least one spring member displaceable when one kind of card is inserted, thereby permitting only one kind of card to be inserted with the aid of the locking member and the spring member. FIGS. 1, 2 and 3 of the Patent Literature 2 show contacts each correspond to respective card in one-to-one relationship.
In recent years, miniaturizations have proceeded in the information appliances as well as substrates or boards used therein so that areas occupied by the substrates have become narrower. Such a limitation of areas occupied by the substrates leads to the use of a plurality of substrates. Moreover, if a plurality of connectors is required for exchanging a plurality of memory cards, information appliances would become bulky which would be inconvenient for carrying them. Consequently, card connectors for receiving a plurality of cards have been proposed as in the Patent Literatures 1 and 2.
The card connectors disclosed in the Patent Literatures 1 and 2 suffer several disadvantages from plural kinds of contacts necessarily required correspondingly to a plurality of cards to be inserted, complicated arrangement of connection portions of the contacts, and difficulties in assembling operationality and mounting operation by a customer. Moreover, as the plural kinds of contacts are required corresponding to the number of cards, areas occupied by the substrates will increase, resulting in limitation of freedom for design of the substrate and connector.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a card connector which overcomes the disadvantages of the prior art described above and which has a high degree of freedom for design of substrate and connector without complicating the arrangement of connection portions of contacts and is easy to assemble and easy to mount connection portions onto a substrate by a customer or consumer.
The above object can be achieved by a card connector 10 into and from which a plurality of cards are inserted and removed, including a required number of contacts 14 each having a contact portion adapted to contact the card, and a housing 12 arranging and holding the contacts 14 and having one or plural fitting openings each into which the card is inserted, wherein according to the invention the contacts 14 each comprise contact portions 22 and 24 to contact at least two cards 50 and 60 so that the same contact 14 can be brought into contact with at least two cards 50 and 60 .
In the case that two cards 50 and 60 are inserted into upper and lower fitting openings arranged one above the other, the above object can be achieved by a card connector 10 into and from which two cards 50 and 60 are inserted and removed one above the other, including a required number of contacts 14 each having a contact portion adapted to contact the card 50 , 60 , and a housing 12 arranging and holding the contacts 14 and having two fitting openings 26 and 28 into which the cards 50 and 60 are inserted, respectively, wherein according to the invention the contacts 14 each comprise contact portions 22 and 24 to contact the two cards 50 and 60 , respectively, so that the same contact 14 can be brought into contact with the two cards 50 and 60 .
The housing 12 includes an upper wall 30 , a lower wall 32 , two side walls 34 for connecting the upper and lower walls 30 and 32 , and a rear wall 36 , and these upper 30 , lower 32 , two side 34 and rear 36 walls form the one or plural fitting openings 26 and 28 , and the two side walls 34 are each provided at the inside with guide means 38 for guiding the card to the contact portions 22 and 24 of the contacts when the card 50 , 60 is inserted.
The contacts 14 each comprise a connection portion 16 at one end adapted to be connected to a substrate or the like, a holding portion 18 provided contiguously to the connection portion 16 for fixing the contact to the housing 12 , and contact pieces 20 at the other end, which are formed by dividing the portion adjacent to and extending from the holding portion 18 toward the other end into a plurality of pieces each having a contact portion 22 , 24 adapted to contact the corresponding card.
The contact pieces 20 of the contacts 14 adapted to contact a card 60 to be inserted into the fitting opening 28 upper than the lowermost fitting opening 26 are bent such that the bent contact pieces 20 of the contacts 14 do not extend into the lower fitting opening 26 . Moreover, the contacts 14 are inserted into the housing 12 from the side of the fitting opening and held in the housing.
As can be seen from the above description, the card connector according to the invention can bring about the following significant function and effect. According to the invention, the connector 10 into and from which a plurality of cards are inserted and removed, including a required number of contacts 14 each having a contact portion adapted to contact the card, and a housing 12 arranging and holding the contacts 14 and having one or plural fitting openings each into which the card is inserted, wherein the contacts 14 each comprise contact portions 22 and 24 to contact at least two cards 50 and 60 so that the same contact 14 can be brought into contact with at least two cards 50 and 60 . Therefore, the card connector 10 according to the invention has a high degree of freedom for design of substrate and connector without complicating the arrangement of connection portions 16 of contacts 14 and without any limitation of areas occupied by substrates, and is easy to assemble and easy to mount connection portions onto a substrate by a customer or consumer.
According to the invention, the card connector 10 into and from which two cards 50 and 60 are inserted and removed one above the other, including a required number of contacts 14 each having a contact portion adapted to contact the card 50 , 60 , and a housing 12 arranging and holding the contacts 14 and having two fitting openings 26 and 28 into which the cards 50 and 60 are inserted, respectively, wherein the contacts 14 each comprise contact portions 22 and 24 to contact the two cards 50 and 60 , respectively, so that the same contact 14 can be brought into contact with the two cards 50 and 60 . Consequently, the card connector 10 according to the invention has a high degree of freedom for design of substrate and connector without complicating the arrangement of connection portions 16 of contacts 14 and without any limitation of areas occupied by substrates, and is easy to assemble and easy to mount connection portions onto a substrate by a customer or consumer.
According to the invention, the housing 12 includes an upper wall 30 , a lower wall 32 , two side walls 34 for connecting the upper and lower walls 30 and 32 , and a rear wall 36 , and these upper 30 , lower 32 , two side 34 and rear 36 walls form the one or plural fitting openings 26 and 28 , and the two side walls 34 are each provided at the inside with guide means 38 for guiding the card to the contact portions 22 and 24 of the contacts when the card 50 , 60 is inserted. Therefore, the cards 50 and 60 can be reliably conducted to the contact portions 22 and 24 of the contacts 14 .
According to the invention, the contacts 14 each comprise a connection portion 16 at one end adapted to be connected to a substrate or the like, a holding portion 18 provided contiguously to the connection portion 16 for fixing the contact to the housing 12 , and contact pieces 20 at the other end, which are formed by dividing the portion adjacent to and extending from the holding portion 18 toward the other end into a plurality of pieces each having a contact portion 22 , 24 adapted to contact the corresponding card. Accordingly, it is possible to provide a card connector 10 which is able to be connected to a plurality of cards 50 and 60 by the use of the same contacts 14 .
According to the invention, the contact pieces 20 of the contacts 14 adapted to contact a card 60 to be inserted into the fitting opening 28 upper than the lowermost fitting opening 26 are bent such that the bent contact pieces 20 of the contacts 14 do not extend into the lower fitting opening 26 . Therefore, the same contacts 14 can be securely brought into contact with a plurality of cards 50 and 60 and there is no card to which the contacts could not be connected.
According to the invention, the contacts 14 are inserted into the housing 12 from the side of the fitting opening and held in the housing. Therefore, the contacts 14 having a plurality of contact pieces 20 can be easily inserted into the housing 12 , and unintentional deformation of the contacts 14 is easy to confirm.
The invention will be more fully understood by referring to the following detailed specification and claims taken in connection with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a card connector viewed from the above on the fitting opening side;
FIG. 1B is a perspective view of the card connector similar to that shown in FIG. 1A , with the upper wall of the housing removed;
FIG. 2A is a perspective view of the card connector with a card inserted into the upper fitting opening;
FIG. 2B is a perspective view of the card connector with a card inserted into the lower fitting opening;
FIG. 3 is a perspective view of a contact used in the card connector; and
FIG. 4 is a front view of the card connector.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the invention will be explained with reference to FIGS. 1A to 4 . FIG. 1A is a perspective view of the card connector viewed from above on the side of its fitting opening, while FIG. 1B is a perspective view of the card connector similar to that shown in FIG. 1 with the upper wall of its housing removed. FIG. 2A is a perspective view of the card connector with a card inserted in the upper fitting opening, while FIG. 2B is a perspective view of the card connector with a card inserted in the lower fitting opening. FIG. 3 is a perspective view of a contact used in the card connector according to the invention. FIG. 4 is a front elevation of the card connector.
The card connector 10 according to the invention mainly comprises contacts 14 and a housing 12 .
Before explaining the components of the card connector, the cards will be explained. The cards are used for printers, card readers and the like. The cards each mainly comprise contact portions adapted to contact the contact portions 22 and 24 of the contacts 14 , patterns connecting from the contact portions of the card to circuits, and connection portions adapted to be connected to integrated circuits and central processing units mounted on the patterns. Cards to be used for the card connector 10 according to the invention include MULTIMEDIA card, SD card (SECURE DIGITAL memory card), MEMORY-STICK, SMARTMEDIA, COMPACTFLASH, XD card, MEMORY-STICK DUO, and the like, these being IC cards having built-in central processor unit (CPU) or integrated chips (ICs) used as memory devices for storing information.
With the card connector 10 in the illustrated embodiment, the Memory-Stick 60 is inserted into the upper fitting opening, and the Memory-Stick Duo 50 is inserted into the lower fitting opening.
First, the contact 14 will be explained which is a subject matter of the invention. The contacts 14 are made of a metal and formed by means of the press-working of the known technique. Preferred metals from which to form the contacts 14 include brass, beryllium copper, phosphor bronze and the like which comply with the requirements such as electric conductivity, springiness, workability, and the like.
The contact 14 comprises at least contact portions 22 and 24 adapted to contact the plurality of cards 50 and 60 , respectively, a holding portion 18 to be fixed to the housing 12 , and a connection portion 16 to be connected to a substrate.
An important aspect of the contact 14 according to the invention lies in the feature capable of contacting a plurality of cards. For example, the contact 14 can contact both the Memory-Stick 60 inserted in the upper fitting opening and the Memory-Stick Duo 50 inserted in the lower fitting opening of the card connector. While the contact can contact the two cards 50 and 60 as shown in FIG. 3 , it will be apparent that it is possible to design the contact to be able to contact more than two cards.
While the connection portion 16 of the contact 14 is of a surface mounting type (SMT) in the illustrated embodiment, it may be of a dip type. The connection portion 16 of the contact 14 may be suitably designed according to a specification of the substrate to which the connection portion 16 is connected. In the illustrated embodiment, the connection portion 16 extends onto the side of the insertion of the cards 50 and 60 (on the side of the fitting openings 26 and 28 for the cards), although the connection portion 16 may extend onto the opposite side of the fitting openings. The extending direction of the connection portion may be suitably designed in consideration of the specification of the substrate, positions of the contact portions of the cards 50 and 60 and positions of insertion of the cards into the upper and lower fitting openings. It is preferable to insert and hold the contact 14 into the housing from the side of the fitting opening (from the side of the insertion of the cards) in view of easier insertion of the contact and easier ascertainment of deformation of the contact.
The holding portion 18 of the contact 14 serves to fix the contact 14 to the housing 12 by press-fitting arrow-head members into the housing 12 , the arrow-head members being previously provided at the holding portion 18 to extend in width directions. Other than the press-fitting, it may be fixed to the housing 12 by hooking, welding, or the like. The size of the holding portion 18 may be suitably designed in consideration of the fact that the forwardly extending portion from the holding portion 18 is divided into a plurality of contact pieces 20 as described below, and the strength of the housing 12 , miniaturization of the card connector 10 and the like. In the illustrated embodiment, the holding portion 18 is approximately 25 mm in width.
As described above, in order to bring the contact 14 (a single contact) into a plurality of cards (two cards in the illustrated embodiment), the forwardly extending portion from the holding portion 18 is divided into two contact pieces 20 extending in the longitudinal direction in the illustrated embodiment. The contact pieces 20 are each provided at its tip with a contact portion 22 , 24 adapted to contact the respective card 50 , 60 . Positions of the contact portions 22 and 24 are suitably designed so that they extend into the respective fitting openings 26 and 28 to obtain predetermined contact pressures as shown in FIG. 1B , and further in consideration of positions of the contact portions of the cards 50 and 60 to be inserted and recognition of the cards to be inserted into the upper and lower fitting openings. As the Memory-Stick 60 is to be inserted into the upper fitting opening and the Memory-Stick Duo 50 is to be inserted into the lower fitting opening in the illustrated embodiment, the contact portion 24 to contact the Memory-Stick 60 in the upper fitting opening is longer and arranged at a higher position, and the contact portion 22 to contact the Memory-Stick Duo 50 in the lower fitting opening is shorter and arranged at a lower position. In order to locate the contact portion 24 for the Memory-Stick at the higher position to extend into the fitting opening 28 for the Memory-Stick, the contact piece 20 of the contact 14 is bent at its mid portion. The mid portion of the contact piece 20 at which it is bent is designed so as to avoid the bent portion of the contact piece 20 from extending into the lower fitting opening 26 for the Memory-Stick Duo 50 . In other words, the contact piece 20 of the contact 14 adapted to contact the card 60 to be inserted into the upper fitting opening 28 is bent so as not to extend into the lower fitting opening 26 below the upper fitting opening 28 . Widths of the contact pieces 20 are about one half of the width of the holding portion 18 .
The housing 12 will then be explained. The housing 12 is formed from an electrically insulating plastic material by means of the injection molding of the known technique. The materials suitable for the housing 12 include polybutylene terephthalate (PBT), polyamide (66PA or 46PA), liquid crystal polymer (LCP), polycarbonate (PC) and the like and combination thereof in consideration of dimensional stability, workability, manufacturing cost and the like. The housing 12 may be provided with a required number of fitting openings into which a plurality of cards is inserted, respectively. The housing 12 is provided with two fitting openings 26 and 28 arranged one above the other in the illustrated embodiment. Sizes of the fitting openings 26 and 28 are suitably designed so that the cards 50 and 60 can be inserted into the fitting openings, respectively, and on insertion of the cards 50 and 60 , they can be brought into contact with the contacts 14 .
The housing 12 comprises at least an upper wall 30 , a lower wall 32 , two side walls 34 and a rear wall 36 . A required number of intermediate walls may be provided depending upon the number of cards to be inserted, as the case may be. The upper wall 30 , the lower wall 32 , the two side walls 34 and the rear wall 36 form the upper fitting opening 28 for the Memory-Stick 60 and the lower fitting opening 26 for the Memory-Stick Duo 50 .
The side walls 34 are each provided on the inside with guides 38 for the purpose of facilitating conducting the inserted cards to the respective contact portions 22 and 24 of the contacts. Sizes of the guides 38 may be determined to enable the cards 50 and 60 to be guided to the respective contact portions 22 and 24 of the contacts and may be suitably designed in consideration of the sizes of the cards 50 and 60 and the strength of the housing 12 .
Although the card connector having two fitting openings for the cards 50 and 60 arranged one above the other is shown in the illustrated embodiment, it is to be understood that a card connector may be constructed to bring a plurality of cards into contact with the same contacts irrespective of the number of cards.
Examples of applications of the present invention are card connectors 10 for use in electric and electronic appliances in instruments and for use in printers and card readers and particularly card connectors capable of accommodating a plurality of cards with the same contacts 14 .
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details can be made therein without departing from the spirit and scope of the invention. | A card connector into and from which a plurality of cards are inserted and removed, includes a required number of contacts, and a housing arranging and holding the contacts and having one or plural fitting openings each into which the card is inserted. The contacts each includes contact portions to contact at least two cards so that the same contact can be brought into contact with at least two cards. The card connector has a high degree of freedom for design of substrate and connector without complicating the arrangement of connection portions of contacts and is easy to assemble and easy to mount connection portions onto a substrate by a customer or consumer. | 7 |
RELATED APPLICATION DATA
[0001] This application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. patent application Ser. No. 60/401,034, filed Aug. 6, 2002, entitled “The Bear Claw,” which is incorporated herein by reference in its entirety. This application is also a Divisional Application of U.S. application Ser. No. 10/634,760, filed Aug. 6, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to barrier devices. In particular, this invention relates to a portable, modular, vehicle barrier.
[0004] 2. Description of Related Art
[0005] Vehicle barriers come in a plurality of different sizes, shapes and materials. For example, the “Jersey Wall” is one of the most common and widely used barrier devices. Typically Jersey Walls are made of preformed concrete and are moved with a forklift or dedicated Jersey Wall mover.
[0006] An alternative type of barrier are those seen around military installations and heavily guarded facilities where a hydraulically operated steal plate is embedded in the roadway. To block incoming traffic, the steal plate is raised in a ramp-like configuration to a height suitable for stopping traffic. These types of devices are permanent in nature and are usually installed in a concrete road surface and have an associated control and power facility.
SUMMARY OF THE INVENTION
[0007] While existing systems tend to provide a certain level of protection, they are not always portable, scalability can be difficult to achieve and they tend to be more of a permanent type barrier.
[0008] An exemplary embodiment of the invention is directed toward a barrier, such as a vehicle barrier. The barrier can be used in, for example, high risk traffic stops, as a barrier around or partially around a protected facility, as a barricade for forward stationed basis, or, for example, by a security team around compounds, facilities and/or homes.
[0009] The exemplary barrier, due to its configuration, not only provides incredible vehicle stopping power but also disables vehicles that breach the barrier by, for example, causing significant damage to the undercarriage, motor components and tires.
[0010] Aspects of the present invention relate to a barrier. In particular, aspects of the invention relate to a vehicle barrier.
[0011] Aspects of the invention further relate to a modular vehicle barrier that is disassembleable.
[0012] Aspects of the invention further relate to a vehicle barrier whose components are scalable.
[0013] Furthermore, aspects of the present invention relate to a vehicle barrier that engages with a surface to facilitate stopping of an oncoming vehicle.
[0014] Additional aspects of the invention also relate to a barrier device adapted to support additional security features such as, for example, barbed wire, constantina wire, spikes, or the like.
[0015] These and other features and advantages of this invention are described in, or apparent from, the following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The embodiments of the invention will be described in detailed, with reference to the following figures, wherein:
[0017] FIG. 1 is a environmental view of an exemplary barrier according to this invention;
[0018] FIG. 2 is a side view of a first exemplary embodiment of a plate according to this invention;
[0019] FIG. 3 is a side view of a second exemplary embodiment of a plate according to this invention;
[0020] FIG. 4 is a side view of a third exemplary embodiment of a plate according to this invention;
[0021] FIG. 5 is a side view of a plate according to this invention;
[0022] FIG. 6 is a perspective view of an exemplary interconnected barrier system according to this invention;
[0023] FIG. 7 is a perspective view of a second exemplary embodiment of a barrier system according to this invention;
[0024] FIG. 8 is a partial cross-sectional view of a plate according to this invention;
[0025] FIG. 9 is a partial cross-sectional view of a plate according to this invention; and;
[0026] FIG. 10 is a partial cross-sectional view of a plate according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The exemplary systems of this invention will be described in relation to a barrier. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures and devices that may be shown in a summarized form. For the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It should be however appreciated that the present invention may be practiced in a variety of ways beyond the specific details set forth herein.
[0028] For example, while the present invention will be described in relation to a barrier having, in general, a hat-shaped structure, it is to be appreciated that the barrier can be combined with one or more other barriers using an interlocking mechanism as discussed herein to further expand the protection afforded by the unit. Furthermore, it should be appreciated that while the exemplary embodiment is illustrated as having substantially flat plates, other sizes, shapes and combinations of shaped plates could also be used without affecting the operability of the system. Additionally, while the panels are preferable constructed of a steal, such as AR500 or Birnell steal, it should be appreciated that other types of steals, compositions, composites, and combinations of materials can be used. For example, the plates could be a multi-layered material that could include carbon fiber, Kevlar® or the like.
[0029] FIG. 1 illustrates an exemplary embodiment of the barrier 1 . The barrier 1 comprises a plurality of plates 100 interconnected by interconnecting member 5 . As can be seen in FIG. 1 , and in accordance with this exemplary embodiment, the plates 100 have a witch-hat shaped design that, when combined with one or more other plates 100 provides a self-standing barrier 1 .
[0030] Thus, in operation, when the barrier 1 is approached by a vehicle generally in direction “A” the barrier is capable of stopping or substantially reducing the speed of the oncoming vehicle by pivoting on the corners opposite the side on which the vehicle engages the barrier.
[0031] While the exemplary barrier 1 illustrated in FIG. 1 comprises nine plates 100 and two interconnecting members 5 , it should be appreciated that any number of plates and interconnecting members can be used without effecting the operation of the invention. For example, to facilitate portability, the barrier 1 could be provided as a kit comprising four plates 100 and two interconnecting members 5 .
[0032] FIG. 2 is a side view of a exemplary plate 100 according to this invention. In particular, the plate 100 comprises a top portion 10 , feet 20 and 30 , sidewalls 40 and 50 and interconnecting members 5 . In accordance with this exemplary embodiment, the plate 100 has an witch-hat shaped configuration where the top portion 10 is substantially parallel to the base comprising the feet 20 and 30 . Similarly, the sidewalls 40 and 50 are provided at an orientation that the distance there between is greater where they intersect the feet than where they intersect the top portion 10 . While this configuration facilitates uprighting of the plate 100 upon contact by a vehicle, it should be appreciated that the exact dimensions and configuration can be varied in size and shape and the feet adjusted without affecting the operation of the invention. For example, the size and shape of the feet 20 can be varied based on the material the barrier is to be placed on. Specifically, and for example, in an asphalt type environment, it may be advantageous to have the feet 20 and 30 in a pointed type configuration. Alternatively, in a sandy environment, it may be advantageous to have the feet 20 and 30 in a flattened or partially-flattened configuration to aid in supporting the barrier 1 on top of the sand. Likewise, it may be advantageous to have foot 20 in a pointed configuration and foot 30 in flattened configuration or any other combination of feet structures as appropriate for the given conditions.
[0033] In accordance with this exemplary embodiment, the plate 100 is attached to adjacent plates via two interconnecting members 5 that are, for example, round and pipe-shaped that interconnect the plurality of plates 100 .
[0034] FIG. 3 is a side view of the second exemplary embodiment of a plate 200 . The plate 200 comprises a rounded top portion 210 , feet 200 and 230 , and interconnecting members 25 . In this particular exemplary embodiment, the interconnecting members 25 are bar-shaped and can be, for example, tubular or a solid member constructed out of any type of material. The rounded top portion 210 provides a less aggressive top portion that, while still maintaining the functionality of the barrier 1 , may be more appropriate around highly populated areas or areas where a large number of personnel may be in close proximity to the barrier 1 .
[0035] FIG. 4 illustrates a third exemplary plate 300 . The exemplary plate 300 comprises a top spiked portion 310 , feet 320 and 330 , and interconnecting members 35 and 45 . In accordance with this exemplary embodiment, the top portion 310 has two or more spike-shaped protrusions that provide a more aggressive barrier 1 and can, for example, provide additional stopping power as the barrier is rotated onto the top portion upon contact by a vehicle. Furthermore, the exemplary plate 300 is interconnected to adjacent plates by a bar 35 and/or T-shaped interconnecting member 45 . Additionally, the feet 320 and 330 are configured such that the plate 300 substantially has an inverted T-shaped configuration.
[0036] While the exemplary embodiments of the plates 100 , 200 and 300 in FIGS. 2, 3 and 4 show various combinations of feet, interconnecting members and top portions, it should be appreciated that these various features can be swapped and interchanged in any combination as appropriate. Also, the top portions and feet can also be different shapes such as semi-hexagonal, semi-octagonal, jagged, or the like. Furthermore, it should be appreciated that the interconnecting members can be in any number, size, shape or configuration, fixed or removable, provided they are capable of supporting a plurality of plates 100 in a substantially upright configuration.
[0037] In addition, it should be appreciated that the plates 100 , 200 and 300 can be fitted with, for example, reflective tape to facilitate visibility, painted in any color, provided with a facade to help facilitate, for example, blending into a particular environment, or provided with supports to carry additional barrier devices that are commonly seen around compounds, facilities and homes such as barbed wire, razor wire, electric fence, signs, a continuous or pseudo-continuous board above the top portion and substantially parallel to the uppermost interconnecting member, or the like.
[0038] FIG. 5 illustrates a side view of an exemplary embodiment of the plate 100 in an overturned position after, for example, contact by a vehicle. Thus, in operation, as a vehicle approaches from direction “A” as illustrated in FIG. 1 , and comes into contact with the barrier 1 , the barrier 1 overturns with foot 30 acting as a fulcrum forcing foot 20 into the undercarriage of the vehicle with the top portion 10 engaging the ground surface 3 to facilitate stopping of the vehicle. Given the symmetric nature of the plate 100 , regardless of the direction of impact, the barrier 1 is capable providing the same type of stopping and undercarriage damaging characteristics. In addition to foot 20 causing undercarriage damage to the vehicle, the foot 20 is also capable of lifting the vehicle that struck the barrier 1 off the ground to further facilitate stopping.
[0039] FIG. 6 illustrates a perspective view of an exemplary configuration of a plurality of interconnected barriers 1 . In particular, the barriers 1 are set up in a substantially parallel but offset pattern and interconnected by fastener 25 . Using this toe-to-toe configuration, the plurality of barriers can be established in a stair-shaped pattern, a zig-zag pattern, or any other pattern as appropriate. For example, while in the exemplary embodiment in FIG. 6 the two barriers 1 are connected by fastener 25 , it should be appreciated that the barriers need not be interconnected by fasteners but could also be placed end-to-end or substantially end-to-end as appropriate.
[0040] Specifically, FIG. 7 illustrates an exemplary embodiment where two barriers 1 are interconnected end-to-end with fasteners 75 . The fasteners 75 , as with the fastener 25 , can be any known or later developed fastener such as a nut and bolt, pin and cotter key, or any other known or later developed fastener. Likewise, while the illustrated embodiments in FIGS. 6 and 7 show the particular orientations of the barrier sections in relation to one another, it should be appreciated that the barriers can be arranged in any configuration and interconnected in any matter as appropriate.
[0041] FIG. 8 is a partial cross-sectional view of plate 100 . In this exemplary embodiment, the interconnecting members 5 pass through the plate 100 and the plate 100 is secured between two fasteners 15 . In accordance with this exemplary embodiment, the fasteners 15 are keys however it should be appreciated that any type of fastener can be used in conjunction with the barrier systems and plates discussed herein. Furthermore, while the exemplary embodiment illustrated in FIG. 8 shows the interconnecting members 5 being removable from and slideable through the plate 100 , it should be appreciated that the interconnecting members 5 could also be securely fastened to the plate 100 for example, by welding, or the like. In addition, it should be appreciated that the interconnecting members 5 could extend beyond an end plate and be adapted to be interconnect with an adjoining barrier. For example, the interconnecting members could have a male-female relationship where adjoining interconnecting members of the barriers would slide together thereby providing a substantially uniform interconnecting member between the plurality of barriers. In addition, it should be appreciated that the spacing between the plates 100 can be varied for example, by placing a plurality of holes 17 in the interconnecting member 5 as illustrated in FIG. 10 . This could provide, for example, additional rigidity by allowing an increased number of plates in the barrier 1 which may be appropriate for a particular application.
[0042] FIG. 9 is a partial cross sectional view of a plate 100 in accordance with another exemplary embodiment of this invention. In particular, in this embodiment, the interconnecting member 5 comprises a threaded male portion 21 and a threaded female portion 23 . The interconnecting member 5 has a greater diameter than the threaded male portion 21 and the threaded female portion 23 thereby securing the plate 100 there between.
[0043] It is, therefore, apparent that there has been provided, in accordance with the present invention, a barrier system. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications, variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, the disclosure is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention. | A portable and scaleable barrier uses a unique combination of feet, interconnecting members and top portions to provide a vehicle barrier that is capable of, for example, lifting the vehicle of the ground and providing substantial undercarriage damage. The interconnecting nature of the barrier allows the barrier to be configured or adapted based on, for example, a particular environmental condition or application. | 4 |
BACKGROUND OF THE INVENTION
This invention is concerned with a process for producing reinforced polymer sheet by paper-making technology, starting from an aqueous dispersion of a particulate thermoplastic polymer and reinforcing fibers having a minimum length of 2 mm.
It is known to produce fiber reinforced polymer articles of manufacture by various methods, e.g. melt-extrusion of a fiber-containing polymer composition to form sheet, film, slabs, tubes, piping, profiles etc., calendering of similar compositions to form sheet or film, injection-molding, blow-molding and compression-molding of similar compositions to form molded objects, particularly those having a reduced wall-thickness, e.g. cups, bottles and other containers. Such techniques present no particular problems provided staple fibers of relatively short length, i.e. having a length of less than 2 mm, are employed. With longer fibers very few of the above techniques are to date practiced on a truly commercial scale since there are very restricted possibilities for achieving the desired degree of homogeneity in the mixture of fiber and polymer at the moment the molding or shaping is about to be effected. Since the reinforcing effect is a function of fiber length, there exists a general incentive to employ longer fibers, e.g. having a length of at least 5 mm. The process as used by Azdel Inc., disclosed in U.S. Pat. Nos. 4,692,375 and 4,615,717, comprises impregnation of a mat of glass fiber strands with a hot molten thermoplastic resin from an extruder, and cooling the resin to form a finished fiber reinforced thermoplastic resin sheet. The product of this process is a flat composite sheet having good tensile strength in the longitudinal direction of the sheet.
It has been proposed to solve the problem related to the processing of long reinforcing fibers in thermoplastics by a completely different technology which is a paper-making process based upon using a thermoplastic polymer in particulate form e.g. a powder or granules, ground down to a very small particle size, as a binder for the fibers. Thus, a paper is produced when the fibers are cellulose fibers, or a paper-like material or synthetic paper can be produced from metal fibers, glass fibers, carbon fibers, nylon fibers, polyamid fibers, etc.
The commercial development of this different technology basically hinges around the use of olefin polymers, e.g. polyethylene, polypropylene or polybutene as the binding polymer. EP-A 6930, EP-A 100720, EP-A 180863 and FR-A 2530724). The binding performance of such polyolefins is however rather poor, most likely due to their hydrophobic properties. Typically, it is necessary to use various surfactants, detergents or flocculating agents in order to improve wettability performance of the polyolefins. These auxiliary agents may even have to be employed at different stages of the paper-making process, which significantly complicates the technology. There is thus a need to find a simplified process for making paper.
Unexpectedly, the Applicants have found that another thermoplastic polymer has a good wettability and that there is no strict need to employ the auxiliary agents referred to hereinabove. This polymer is an alternating copolymer of carbon monoxide and an olefinically unsaturated compound, with a molecular weight of at least 2000, and more preferably at least 6000, known as polyketone.
The present invention differs from the Azdel process in that it (A) comprises staple fibers instead of a mat of fiber strands, (B) dispenses an aqueous suspension of grinded polymer together with fibers onto a filter and thereafter removing the water and drying at elevated temperature the self-supporting sheet of reinforced polymer, and (C) compression molds the preform. The product of the present invention is a reinforced, optionally shaped, polymer article. Furthermore, the polymer of the present invention is an alternating copolymer of olefinically unsaturated compounds and carbon monoxide which are very suitable for this process.
SUMMARY OF THE INVENTION
The present invention is concerned with a process for producing a fiber reinforced polymer sheet by paper-making technology, starting from an aqueous dispersion of a particulate thermoplastic polymer and reinforcing fibers with a length of at least 2.0 mm, characterized in that the polymer is an alternating copolymer of carbon monoxide and an olefinically unsaturated compound with an average molecular weight of at least 6000, and more preferably at least 2000, with the fibers so employed, in an amount of from 5 to 450 pbw per 100 pbw of copolymer, preferably in an amount of from 20 to 200 pbw per 100 pbw of copolymer.
The particle size of the copolymer should be such that adequate handling of the product in the machinery is obtained. Both the presence of particles which are too small or too large for this purpose is to be avoided. Preferred particle sizes are of from 0.01 to 0.75 mm, best of all selected in the range of from 0.05 to 0.30 mm. Preferred fiber lengths are at least 4.5 mm.
DETAILED DESCRIPTION
Alternating copolymers of olefinically unsaturated compounds and carbon monoxide are known per se. They can be produced with a catalytic copolymerization process disclosed for example in EP-A 121965, and EP-A 181014.
The term "copolymer" as used in this specification includes terpolymers of an olefinically unsaturated compound, e.g. ethylene, carbon monoxide and another olefinically unsaturated compound such as styrene, norbornene, propylene, butene-1, decene, and vinylacetate. If terpolymers are used herein, terpolymers with melting points of 215° C. to 240° C. are preferred.
The term "alternating" as used herein defines those copolymers having the general formula [A--CO] n , and wherein each --CO-unit in the macromolecular chains is bound left and right to a monomer unit --A--, which is --CH 2 --CH 2 -- in a copolymer of ethylene and cabon monoxide. In a terpolymer some of the --CH 2 --CH 2 -- units in that formula can be replaced by a unit of another olefinically unsaturated compound. Such substitution effects a lowering of the melting point of the ethylene/carbon monoxide copolymer, preferred terpolymers are those of ethylene, propylene and carbon monoxide having a melting point in the range of from 215° to 240° C.
The implementation of the process of this invention presents no problems to those skilled in the art. The process of this invention is a wet-laid aqueous technique. Similar processes are disclosed in U.S. Pat. Nos. 4,426,470 and 4,431,696, U.K. Pat. No. 1,263,812, French Patent Publication No. 2,507,123, and European Patent Publication No. 0,039,292. A homogeneous dispersion in water of reinforcing fibers and the novel thermoplastic polymer particles is brought on the filtering equipment of a paper-making machine, the water is drained-off, thus yielding after drying at elevated temperature a self-supporting sheet of reinforced polymer. Suitable paper-making machine can be Beloit Continuous Pulp Machine, a Fourdrinier Machine or a Cylinder Machine. For further processing, several of these sheets can be stacked together and compression molded at a temperature around or above the melting point of the polymer.
Compression-molding can also be carried out with stacked sheets that have been united to form one coherent sheet of increased thickness in a previous forming operation, e.g. calendering, in which use may be made of adhesive films or coatings on the various layers of sheets.
The reinforced copolymer compositions of this invention may further comprise various additives such as fillers, colorants, plasticizers, thermostabilizers or antioxidants. Other polymeric constituents may be incorporated as well, for example polyethylene or polypropylene and it is also possible to use hybrids for the reinforcing fibers.
The invention is illustrated herein with Examples which are not intended to restrict the scope of the working conditions for practicing the process of the invention.
EXAMPLES
A powder of an ethylene/propylene/carbon monoxide terpolymer, with a crystalline melting point of 221° C. and an intrinsic viscosity of 1.01 dl.g -1 , was stirred to a dense suspension in demineralized water not containing any surfactant or flocculant. Then various fibers were added as indicated in the Table below, all fibers had a length of 6 mm. the fibers were defibrillated by continuous, vigorous stirring of the suspension having a solids content of 1 g.l -1 . The suspension was poured onto a filter, water was drained off and the resulting, selfsupporting sheet was positioned between two layers of filter paper forming an assembly. The assembly was rolled with a heavy roller to absorb most of the water in the wet sheet. Final drying was effected by drying overnight at ambient temperature and in a vacuum under N 2 at 50° C. for 3 hours.
Each single sheet was compression-molded in a hot press using 1 mm thick metal supports. The molding conditions used herein are detailed on the following Table I.
TABLE I__________________________________________________________________________Compression Molding Conditions POLYKETONE POLYKETONE POLYKETONE POLYKETONE ARAMID CARBON (REFERENCE) GLASSFIBER FIBER FIBER__________________________________________________________________________Single SheetPreheatingTime (Min.) 0.5 1 0.5 lTemp (°C.) 235 235 235 Z35Press. (Tons) 1.5.sup.1 1.5 1.4 1.5CompressionMoldingTime (Min.) 0.5 0.5 0.5 0.5Temp (°C.) 235 235 235 235Press. (Tons) 4 15 7.2 15CoolingTemp. R.T. R.T. R.T. R.T.Press. (Tons) 4 15 7.2 15Preheating inan Oven10 Min, 110° C. No Yes Yes YesTest SheetPreheatingTime (Min.) 0.5 1 0.5 1Temp (°C.) 235 235 235 235Press. (Tons) 1.5.sup.2 1.5 1.4 3CompressionMoldingTime (Min.) 0.75 0.5 0.5 0.5Temp (°C.) 235 235 235 235Press (Tons) 4 15 7.2 30CoolingTemp. R.T. R.T. R.T. R.T.Press (Tons) 4 15 7.2 30__________________________________________________________________________ .sup.1 Initial surface area ca. 100 CM2. .sup. 2 Surface area after first time compression molding. Four compressionmolded sheets were stacked, preheated in an oven at 110° C. and once more compressionmolded at 235° C. to obtai a testsheet with a thickness of 0.7 to 1.0 mm.
For reference purpose, single sheets of terpolymer were produced by compression-molding terpolymer powder at the same temperature indicated above. Four sheets so obtained were then stacked and compression-molded at 235° C. to obtain a test-sheet with a thickness of 0.7 to 1.0 mm. In table II which follows, the reported amounts of fiber are pbw per 100 pbw of terpolymer.
TABLE 11______________________________________Fibers None Glass Polyaramid Carbon______________________________________Amount 0 33 18.5 24.5Tensile strength, MPa 50 120 125 150E-modulus, Gpa 1.7 5.1 4.6 10.1______________________________________
All molded samples of reinforced polymer showed a homogeneous distribution of fibrillated fibers in the polymer matrix. | A process for producing a fiber reinforced polymer sheet by paper-making technology starting from an aqueous dispersion of thermoplastic polymer particles and fibers having a minimum length of 2.0 mm, characterized in that the polymer is an alternating copolymer of ethylene and carbon monoxide with an average weight molecular weight of at least 6000 and the fibers are used in an amount of from 5 to 450 pbw per 100 pbw of polymer. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fastening and securing devices in industrial, clothing, and other applications, and, more specifically, to belts and strap-type fastening devices.
2. Description of the Prior Art
There are many industrial, clothing, and other applications which require the use of fastening and securing devices, such as, straps, belts, and ties. The prior art discloses variations of these devices in many different configurations and designs. Often, these devices require the use of an independent closure or buckling mechanism, which may or may not be permanently attached to the device. A well known example is the clothing belt. This belt comprises a strap of fabric, leather, or other material with a separate buckle typically made from plastic, metal, or wood. Usually, the buckle is semi-permanently attached to the strap.
Leather belts are very popular in the prior art. Nevertheless, leather is a material that could have limited availability and does not offer the potential for large scale automated production. Furthermore, leather, as with most types of materials for clothing belts, has limited potential for decoration or novel visual colors, textures, and cosmetic details.
In addition, many of the prior art closure devices are produced using labor-intensive processes. Consequently, these processes may result in relatively expensive or, alternatively, low-quality final products.
Another limitation of the prior art regards the modular creation of large belts from smaller pieces. One may be able to join two or more small belts together to form a larger belt, but the procedure is very awkward and the resulting belt may be difficult to maneuver.
Overall, the prior art closure devices do not lend themselves to wide flexibility in the manufacturing process and require separate buckling mechanisms.
SUMMARY OF THE INVENTION
A primary object of this invention is a fastening device or belt that contains an integral buckling mechanism.
Another object of this invention is a fastening device or belt that is of modular design.
Another object of this invention is a fastening device or belt which is of adjustable length.
Another object of this invention is a fastening device or belt that is strong while lightweight.
Another object of this invention is a fastening device or belt that is economical to produce, while retaining high quality.
Another object of this invention is a fastening device or belt that may be produced in a variety of colors, shapes, embossed patterns, and textures.
In short, this invention comprises a strip of transparent or colored plastic molded in a desired shape. At one end of the strip are a plurality of hooks; at the other end of the strip are a plurality of receptors. Moreover, one embodiment has similar ends that can function as either hook or receptor, thereby simplifying mold design and reducing mold cost. Molding can be done by open mold or injection molding processes.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a fastening device or belt.
FIG. 2 is a mold for producing two of the fastening devices or belts shown in FIG. 1.
FIG. 3 is a cross-section of the mold shown in FIG. 2 taken at A--A.
FIG. 4 is the fastening device or belt shown in FIG. 1 with the flash not completely removed.
FIG. 5 is a cross-section of the fastening device or belt shown in FIG. 4 taken at B--B.
FIG. 6 is a fastening device being used with eyeglasses.
FIG. 7 is a section of the fastening device shown in FIG. 6 with its effective length reduced by use of a molded ring cut from an end loop of the fastening device.
FIG. 8 is a section of a fastening device being used with a key.
FIG. 9 is a fastening device being used with a key in a manner different than shown in FIG. 8.
FIG. 10 is a section of a fastening device being used with a whistle.
FIG. 11 is a double-stranded fastening device being used as a belt.
FIG. 12 is a section of the double-stranded fastening device shown in FIG. 11.
FIG. 13 is the area of interlocking of two separate fastening devices or belts to form a longer fastening device or belt.
DESCRIPTION OF PREFERRED EMBODIMENT
In its preferred embodiment, this invention is a fastening device or belt in the form of a strap 1 that can be produced by an automated molding process. The device 1 is fashioned from plastic molded in a desired shape. Because the plastic molding process is well known, widely available, and cost-effective, use of this process can produce a low-cost product having various designs and novel appearance details.
The strap 1 may be fabricated from many different plastics and elastomers. The preferred materials are polyurethane elastomers. Although these elastomers are available in many different formulations, the preferred formulation is a two-component urethane system that can be cured rapidly at moderate temperature (180° F. to 230° F.).
The strap 1 can also be made by use of a vinyl plastics. This is a single-component molding compound, which requires a cure temperature of about 350° F. for several minutes. Other plastics can also be used to produce this device.
At one end of the strap 1 are a plurality of hooking mechanisms 2. At the other end of the strap 1 are a plurality of receptor mechanisms 3. Preferably, the hooking mechanisms 2 and the receptor mechanisms 3 are identical to each other, both being a plurality of loops 10. Although the loops 10 may be of similar size, they are preferably of varying size. The shape of the loops 10 can be circles, ellipses, squares, rectangles, or similar configurations. The elastomer used to mold the strap 1 is preferably flexible enough that a loop 10 from one end can be bent or folded and then forced into a loop 10 on the other end. This action causes the loops 10 so engaged to interlock securely. The elastomer is also sufficiently rigid so that the interlocked loops 10 cannot readily be pulled apart. Thus, the preferred material for the strap 1 is a polyurethane elastomer with a Shore A2 durometer of approximately 90.
Two straps 4, 5 may also be linked together to form a larger strap 6, as shown in FIG. 13. Such linking is accomplished as follows: A loop 11 at one end of the first strap 4 is interlocked with a loop 12 at one end of the second strap 5. Thus, one now has a larger strap 6 which is ready for use. Additional straps may be linked onto the larger strap 6 to produce an even longer strap.
The strap 1, or belt, has ends 2, 3 which can be securely locked together so that significant force is required to open the interlocked connection. The force needed for separation of the ends 2, 3 can be increased or decreased by, respectively, increasing or decreasing the number of loops that are interlocked. This interlocking avoids the need for a separate and relatively expensive buckle.
The strap 1 can also be used as a connector between two different objects, or to secure a specific object such as eyeglasses 100 around the head, a key 101, 102, or a whistle 103.
This invention is preferably produced by any of a number of different molding procedures, such as casting or injection molding. For casting, the preferable manufacturing process is an open-mold casting process.
The casting process uses an open casting mold 20 that can be produced by end milling or preferably, by photo-etching a magnesium or aluminum plate. The mold has two (2) grooves. One groove 21 will be filled resin (liquid elastomer) to form the strap 1. The other groove 22 provides a defined line so that the flash 15 along the cured, molded strap 1 can be easily and quickly removed.
The fabrication procedure is as follows: The two liquid components of the preferred liquid polyurethane elastomer system are mixed to form a liquid resin. The resin is then poured onto the surface of one end of the mold 20. A straight edge, or knife, is used to draw the resin across the mold 20 so that all the grooves 21, 22 are filled with the resin. The knife also removes excess resin from the exposed top surface of the mold, scraping this top surface clean. Next, the liquid resin is cured. After curing, the resin is peeled out of the grooves 21, 22 to obtain the molded product. Finally, the flash 15 is trimmed off the molded product to produce the final strap 1. Because the mold is open, the internal and external forces acting on the liquid resin will form the resin's exposed top surface into a flat configuration. Thus, the cured strap 1 will have one flat surface 4.
For injection molding, the mold is preferably made from tool steel. The mold contains an opening having two segments. The first segment comprises a flat surface that corresponds to the desired flat surface 4 of the strap 1. The second segment comprises a shape complementary to the contour of the remaining cross-section of the strap 1.
The fabrication process for the injection molding embodiment follows the well-known procedures for injection molding, described in many reference books such as Rubin, Irvin I., Injection Molding: Theory and Practice (John Wiley & Sons, Inc. 1972). In this case, a thermoplastic elastomer, preferably polyurethane in the form of pellets, is used. The pellets are melted in the injection molder and then injected into the injection mold, which is set at room temperature or at a temperature no more than 150° F. After a brief cooling cycle, the mold opens and the molded part is ejected from the mold by use of well-known ejection pins, producing the final strap 1. Because the mold cavity has one flat surface, one surface of the cooled elastomer will have a flat configuration. Thus, the produced strap 1 will have one flat surface 4.
The strap 1 may be used as a belt, as shown in FIG. 11. In this use, the strap 1 is placed around the object to be secured, such as an article of clothing. Loops 10 at the ends 2, 3 are interlocked as discussed above. The strap 1 has now secured the object. The strap 1 is removed by reversing the loop interlocking process.
The strap 1 may also be used to grip objects, as noted above. Because the device preferably has varying size loops, it is versatile for gripping varying sizes and geometry of objects, such as eyeglasses 100, keys 101, 102, or whistles 103.
Finally, the effective length of the strap 1 may be reduced by cutting off one of the loops 10, doubling over the strap at its middle, and threading the doubled strap through the broken-off loop. An example of this ability is shown in FIG. 7, where the strap 1 is used with eyeglasses 100 to secure the eyeglasses 100 during activities such as playing tennis or riding a horse.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and scope of this invention. For example, the composition of the plastic may be chosen to allow for various industrial or household applications. Also, embossing or metallic pigments such as gold or silver may be used for an attractive cosmetic appearance. | A fastening device [or belt] comprising a strip of colored plastic molded in a desired shape with one surface being substantially flat. At both ends of the strip are a plurality of loops. The loops may be interlocked to surround and secure an object, or the loops may be directly attached to the object to be secured. Two strips may be interlocked with each other to create a larger strip. [Also claimed are methods for making this fastening device or belt by open mold or injection molding processes.] | 8 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to the field of hydrocarbon production, more particularly to methods for obtaining a wellbore schematic, and using same to monitor wellbore service operations.
2. Related Art
Due primarily to expense issues, the hydrocarbon production industry has come to accept taking surface measurements and making inferences of the downhole status. However, interpretation of real-time wellbore pressure data requires knowledge of the wellbore schematic, in particular the wellbore's variation of depth below the earth surface (“true vertical depth”, or TVD) versus its depth along the wellbore axis (measured depth, MD or just “depth”). In circumstances where the wellbore schematic is not known in advance by the interpreter, the wellbore schematic may be obtained directly by including a inclinometer in a downhole tool, but this option is not always available or economical.
In making wellbore pressure interpretations, the pressure read by a downhole meter inside a tubular such as coiled tubing will be the pressure in the tubing at the surface (the “circulating pressure”) less friction effects due to flow and plus the hydrostatic pressure, which is proportional to the TVD. For a uniform fluid, the hydrostatic pressure is given by the density of the fluid in ppg times 0.052 psi/ppg/ft. For a typical brine, this works out to approximately 0.5 psi/ft (11.3 kPa/m) of TVD. For a non-uniform fluid, integration along the length of the tubing is required. At zero flow, the TVD is thus given by subtracting the circulating pressure from the bottom-hole pressure and dividing by the constant of proportionality. It is uncommon (and sometimes inefficient) to run coiled tubing into the bottom of the wellbore without pumping fluid, however. When pumping fluid downhole through tubing, the bottom-hole pressure at the terminus of the tubing will be decreased by the friction of the fluid in the tubing. For laminar flow of Newtonian fluids, friction pressure equals a constant multiplied by the flow rate. For turbulent flow of Newtonian fluids, friction pressure equals a constant multiplied by the flow rate squared. In each case the constant of proportionality depends upon the tubing internal geometry as well as the local friction factor between the fluid and the inner tubing surface. For typical fluids pumped through coiled-tubing, there may be a different formula for computing friction loss for the component of the fluid flowing through the spooled coil at the surface, versus that fluid flowing in the tubing hanging in the wellbore. For non-Newtonian fluids, yet more complicated relationships exist between the circulating friction loss and the flow-rate.
In wellbore cleanout procedures and other procedures where liquids are pumped into the wellbore via tubing and out through the annulus, if hydrostatic head pressure may be removed, one has an accurate estimate of the wellbore pressure at the bottom of (entrance to) the annulus. However, the only way to remove the hydrostatic component from downhole data is to have a copy of the wellbore schematic in advance of the job. This schematic could have been obtained while drilling the well via measurement-while-drilling data, or after drilling by lowering a wireline inclinometer tool such as a gyroscope. However, no tool that is currently used for stimulating reservoirs is known to have an internal inclinometry platform, nor is there known any previously existing method to determine TVD strictly from pressure data and flow rate information.
In wellbore cleanout operations, various fill materials are carried by a fluid injected down the wellbore, typically through coiled tubing or other tubulars, and flowed out through the annulus. The cleanout fluid carrying solid particles along the annulus is a suspension whose density correlates with the concentration of solid particles. For an effective cleanout the suspended particles must be transported all the way out of the well. The hydrodynamic pressure in the annulus is directly proportional to the suspension density.
It would be an advance in the art if methods could be devised that provide information about the relationship between TVD vs. MD, in other words the wellbore schematic, while flowing fluids into the wellbore. It would further be an advance in the art to use the obtained wellbore schematic to monitor and/or control wellbore operations, such as wellbore cleanout procedures, via information about the annulus.
SUMMARY OF THE INVENTION
In accordance with the present invention, a wellbore schematic may be estimated from an interpretation of the pressure data itself. Despite the previously-mentioned complications, the designer of a wellbore treatment regime, such as a stimulation treatment, will usually be content to pump a fluid (for example brine) through the tubing for the initial pass into the wellbore. It is during this pass through the wellbore that information about the TVD versus depth may be obtained. Note that it is rather trivial to determine this relationship when not pumping, so one objective of the invention is to derive TVD versus MD relationship while pumping a fluid. Different fluid flow rates may be pumped when different lengths of coiled tubing have been entered into the wellbore. By combining surface measurements of pressure and flow of a known fluid with downhole measurements of pressure, the wellbore schematic may be obtained.
Thus, a first aspect of the invention is a method comprising:
(a) providing a coil of coiled tubing having a length able to reach a determined section of a wellbore; (b) running measured distances of the coiled tubing into a wellbore while pumping a fluid at varying flow rates through the coiled tubing; (c) measuring circulating pressure and pressure at bottom of the wellbore at various times during running and pumping; and (d) calculating wellbore parameters of the wellbore at the one or more measured distances using the pressure and flow rate data.
Methods within this aspect of the invention include methods wherein the wellbore parameters include true vertical depth of the wellbore along the length of the wellbore, and methods comprising cross-plotting the true vertical depth versus the measured distances as a function of time. As used herein “circulating pressure” means the pressure of the circulating fluid measured at the surface just before it enters the coiled tubing. One embodiment comprises pumping a sequence of fluid flow regimes into the wellbore at measured circulation pressures and flow rates, sending bottom-hole data to the surface, and fitting the data to find the wellbore geometry assuming a minimal radius of curvature for the wellbore. The true vertical depth may be cross-plotted versus measured distance as a function of time. Methods include those wherein the density of the pumped fluid is constant or varies, such as when a wellbore cleanout fluid picks up particles from the wellbore and transfers the particles with the fluid out through the annulus of the wellbore. When the density of the fluid changes, a second calculation using pressure measurements at the surface and in the wellbore may be used to calculate, and recalculate if necessary or desired, the fluid density. Alternatively, the density of the pumped fluid may simply be monitored for change of density.
Methods within this aspect of the invention include sending real-time pressure data to the surface during wellbore stimulation using one or more methods selected from wireless methods (such as mud-pulse electromagnetic telemetry), wire methods via a data-carrying wire (such as an eline cable), and fiber-optic lines. The wireless methods may be used particularly when running in joints of tubing. In other embodiments the tubing is brought to the well spooled onto a reel with a telemetry cable already inserted into the spool, but the invention is not so limited. The wireline may be inserted into the tubing at the well site. An advantage of fiber-optic telemetry is that the bottom-hole pressure may be measured without the need for downhole electronics. Indeed, if one has downhole electronics, then an inclinometer may be added to the electronics package for minimal additional cost, so one of the prime advantages of this invention is for bottom-hole assemblies without an electronics package. Fiber-optic techniques to measure pressure are well-known in the industry. One common device relies on interferometry to identify the size of a cavity, that cavity itself changing size based on the external pressure applied to the cavity. Such devices are made, for example, by FISO Technologies in Montreal, Canada and have been recently implemented in the bottom-hole assemblies. Certain methods of this aspect of the invention comprise repeating steps (b), (c), and (d) during repeated passes of the tubing through the wellbore. This may result in more certainty regarding the wellbore schematic.
Once the wellbore schematic is estimated then the same information on the wellbore and fluids may be used to analyze the annulus around the coil. Thus, another aspect of the invention is a method comprising:
(a) pumping a fluid at a wellhead down a wellbore through coiled tubing and measuring pressure and flow rate of the fluid at the wellhead and down the wellbore at a terminus of the coiled tubing, the fluid flowing out of the wellbore through an annulus; and (b) monitoring presence of particles in the fluid with or without detecting variations in their concentration.
One method according to this aspect of the invention comprises calculating the flowing fluid stream density in the annulus, or monitoring variations in fluid density in the annulus. Another method comprises quantifying the amount of fill material removed from the wellbore. In this respect, the methods are an alternative or complement to solids detection in annulus fluids at the wellhead.
Methods within this aspect of the invention include those wherein the wellbore is selected from substantially vertical wellbores, deviated wellbores, and combinations thereof. Other methods comprise determining the quantity f*k geo in the respective vertical and deviated instances, wherein f is the friction coefficient and k geo is a constant that depends on the geometry of the annulus. In certain methods if the quantity f*k geo is known, the density of the fluid in the annulus may be quantified, and therefore the concentration of particles in the fluid. This provides a method to monitor cleanout efficiency of a pumped cleanout fluid carrying the particles to the surface. The quantity f*k geo may be determined during a period of flow where no cleaning is taking place, in other words with no particles in suspension, so that density is known. Alternatively, a plot may be made of the difference between annulus pressure and wellhead pressure as a function of length of tubing in the wellbore, with a set of pre-defined constant density lines. Another alternative is to calculate fluid density at zero flow rate, which may be achieved using short pumping interruptions. As will be shown, this allows calculation of fluid density without the need of taking into account the friction. Such pumping interruptions may only be possible if the particle settling time is sufficiently long, for example with gel fluids.
The method may be a wellbore cleanout operation, and the methods may be monitored. In the context of wellbore cleanout operations, another aspect of the invention is a computation method comprising measuring wellhead pressure at surface, at the flow exit, measuring annulus bottom hole pressure, at the end of the CT string, and measuring the length of coiled tubing run in the wellbore, and determining the qualitative relationship between annulus fluid density and flow rate, without knowing the friction factor or k geo factor for the annulus. Knowing the latter two quantities allows a quantitative measure of annulus fluid density.
Methods of the invention may be used with one or more oilfield tool components. The term “oilfield tool component” includes oilfield tools, tool strings, deployment bars, coiled tubing, jointed tubing, wireline sections, slickline sections, combinations thereof, and the like adapted to be run through one or more oilfield pressure control components. The term “oilfield pressure control component” may include a BOP, a lubricator, a riser pipe, a wellhead, or combinations thereof.
Advantages of the methods of the invention include combining the operations of determining the wellbore schematic with one or more fluid flow regimes at a well site, thus saving time. Determination of a wellbore schematic during fluid injection also eliminates the need for an instrumented bottom hole assembly, possibly allowing more efficient wellbore operations, and provides the opportunity for obtaining more information on annular fluids without having to calculate friction coefficient of the annulus.
Methods of the invention may become more apparent upon review of the brief description of the drawings, the detailed description of the invention, and the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The manner in which the objectives of the invention and other desirable characteristics may be obtained is explained in the following description and attached drawings in which:
FIG. 1 . is a schematic cross-sectional view of a wellbore illustrating calculation parameters for one method of the invention; and
FIG. 2 is a schematic cross-sectional view of a partially vertical and partially deviated wellbore illustrating calculation parameters for another method of the invention.
FIG. 3 is an illustration useful for a method of derivation of well deviation and TVD; and
FIGS. 4A , 4 B, and 4 C illustrate an example of application of the method of FIG. 3 .
It is to be noted, however, that the appended drawings are not to scale and illustrate only typical embodiments of this invention, and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it may be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
All phrases, derivations, collocations and multiword expressions used herein, in particular in the claims that follow, are expressly not limited to nouns and verbs. It is apparent that meanings are not just expressed by nouns and verbs or single words. Languages use a variety of ways to express content. The existence of inventive concepts and the ways in which these are expressed varies in language-cultures. For example, many lexicalized compounds in Germanic languages are often expressed as adjective-noun combinations, noun-preposition-noun combinations or derivations in Romanic languages. The possibility to include phrases, derivations and collocations in the claims is essential for high-quality patents, making it possible to reduce expressions to their conceptual content, and all possible conceptual combinations of words that are compatible with such content (either within a language or across languages) are intended to be included in the used phrases.
The invention describes methods for obtaining a wellbore schematic, defined as the relationship between true vertical distance (TVD) and measured distance (MD) of a tubular in a wellbore. Currently, in wellbore cleanout procedures and other procedures where liquids are pumped into the wellbore via tubing and out through the annulus, if hydrostatic head pressure may be removed, one has an accurate estimate of the wellbore pressure at the bottom of (entrance to) the annulus. However, the only way to remove the hydrostatic component from downhole data is to have a copy of the wellbore schematic in advance of the job. This schematic could have been obtained while drilling the well via measurement-while-drilling data, or after drilling by lowering a wireline inclinometer tool such as a gyroscope. However, no tool that is currently used for stimulating reservoirs is known to have an internal inclinometry platform, nor is there known any previously existing method to determine TVD strictly from pressure data and flow rate information. Another challenge is in so-called wellbore cleanout operations, wherein various fill materials are carried by a fluid injected down the wellbore, typically through coiled tubing or other tubulars, and flowed out through the annulus. The cleanout fluid carrying solid particles along the annulus is a suspension whose density correlates with the concentration of solid particles. For an effective cleanout the suspended particles must be transported all the way out of the well. The hydrodynamic pressure in the annulus is directly proportional to the suspension density. It would be an advance in the art if methods could be devised that provide information about the relationship between TVD vs. MD, in other words the wellbore schematic, while flowing fluids into the wellbore. It would further be an advance in the art to use the obtained wellbore schematic to monitor and/or control wellbore operations, such as wellbore cleanout procedures, via information about the annulus. There is a continuing need for systems and methods that address one or more of these challenges.
As used herein “wellbore schematic” means the relationship between true vertical depth and measured depth, where measured depth is the depth measured at the wellhead of coiled tubing that has entered the wellbore. As used herein “annulus fluid” and “annular fluid” may be used interchangeably and refer to the fluid traversing past a coiled tubing back to the surface. As used herein “wellbore servicing” means any operation designed to increase hydrocarbon recovery from a reservoir, reduce non-hydrocarbon recovery (when non-hydrocarbons are present), or combinations thereof, involving the step of pumping a fluid into a wellbore, or into coiled tubing that is or will be placed into the wellbore. This includes pumping fluid into a reeled or spooled coil of coiled tubing. The fluid pumped may be a composition to increase the production of a hydrocarbon-bearing zone, a composition pumped into other zones to block their permeability or porosity, a composition designed to flush or cleanout a wellbore or portion thereof, and the like. Methods of the invention may include pumping fluids to stabilize sections of the wellbore to stop sand production, for example, or pumping a cementatious fluid down a wellbore, in which case the fluid being pumped may penetrate into the completion (e.g. down the innermost tubular and then up the exterior of the tubular in the annulus between that tubular and the rock) and provide mechanical integrity to the wellbore. As used here in the phrases “treatment” and “servicing” are thus broader than “stimulation”. In many applications, when the rock is largely composed of carbonates, one of the fluids may include an acid and the hydrocarbon increase comes from directly increasing the porosity and permeability of the rock matrix. In other applications, often sandstones, the stages may include proppant or additional materials added to the fluid, so that the pressure of the fluid fractures the rock hydraulically and the proppant is carried behind so as to keep the fractures from resealing. The details are covered in most standard well service texts and are known to those skilled in the well service art so are omitted here.
Methods within this aspect of the invention include sending real-time pressure data to the surface during wellbore servicing using one or methods selected from wireless methods (such as mud-pulse electromagnetic telemetry), wire methods via a data-carrying wire (such as an eline cable), and fiber-optic lines. The wireless methods may be used particularly when running in joints of tubing. In other embodiments the tubing is brought to the well spooled onto a reel with a telemetry cable already inserted into the spool, but the invention is not so limited. The wireline may be inserted into the tubing at the well site. An advantage of fiber-optic telemetry is that the bottom-hole pressure may be measured without the need for downhole electronics. Indeed, if one has downhole electronics, then an inclinometer may be added to the electronic package for minimal additional cost, so one of the prime advantages of this invention is for bottom-hole assemblies without an electronics package. Fiber-optic techniques to measure pressure are well-known in the industry. One common device relies on interferometry to identify the size of a cavity, that cavity itself changing size based on the external pressure applied to the cavity. Such devices are made, for example, by FISO Technologies in Montreal, Canada and have been implemented in the bottom-hole assemblies.
Exemplary methods of the invention rely on running tubing into the bottom of a wellbore while pumping a fluid therethrough at varying rates while running in. The fluid may be one in which the friction drop down tubing, such as coiled tubing, behaves according to a power-law relationship:
friction pressure= A* (flow rate) n ,
where n is an exponent (typically between 1 and 2) and A depends on (i.e., is a function of) viscosity of the fluid, local friction effects and tubular internal diameter. The pressure measured at the bottom of the tubing will be given by the circulating pressure (measured at the surface) less the friction pressure through the tubing plus the hydrostatic pressure. The friction pressure in the coiled tubing may be best modeled as two components:
friction pressure= A 1 *(flow rate) n1 +A 2 *(flow rate) n2
where the first term to the right of the equal sign represents the pressure drop along that part of the coil wound around a spool, and the second term to the right to the equal sign represents the pressure drop along the unspooled coil. This latter component may be taken to be proportional to the length of coil run into the wellbore, so surface measurement of this length will be needed. Apparatus for such measurements are commercially available and well-known in the industry. For example, small wheels may be pushed against the coil and the rotation of those wheels will give the length of the coil run in. One embodiment is that known under the trade designation UTLM, from Schlumberger. The first component of the friction pressure may be modeled either as a formula which takes into account the changing diameter of the spooled coil, or more simply may be taken as proportional to the length of coil wound around the spool. Thus if there is a total of L T feet brought to the rig and MD(t) has been run into the ground at time t, then the friction pressure may take the form:
friction pressure= a 1 *( L T −MD ( t ))*(flow rate( t )) n1 +a 2 *MD ( t )*(flow rate( t )) n2 .
In order to determine the unknown coefficients a 1 and a 2 , and the exponents n 1 and n 2 , the flow rate and MD as the coil is run in may be varied with time. The hydrostatic pressure will be proportional to the density of the fluid times its TVD. In many embodiments the density of the pumped fluid varies with depth and flow rate; however, in some embodiments the density may be assumed to be fixed, so the hydrostatic term becomes:
hydrostatic pressure= TVD ( t )*density*gravity.
One method of the invention is thus to find a best fit of the parameters (TVD(t) vs. MD(t)) which matches up the sum of the theoretical friction pressure and hydrostatic pressure against the difference of the measured circulating and bottomhole pressures. This best fit may be done with a number of techniques for non-linear optimization. Such programs are readily available in software packages, such as Matlab. The result is then a cross-plot of TVD(t) versus MD(t) at each time. This is precisely the wellbore schematic. The terminology Y(t) may be used to denote the difference between theoretical pressure drop in the coil against the measured pressure drop.
In the unlikely event that the density of the fluid is not known at the beginning of the job, it may be estimated if the wellbore schematic is at least known at the top of the wellbore, e.g., if the top of the wellbore is vertical. This estimate could then be used for the rest of the inversion.
The nature of nonlinear parameter estimation means that the plot of TVD(t) versus MD(t) will be quite noisy. This estimation may be made more robust by adding additional information such as the maximum dogleg angle of the wellbore. A second piece of information is that the borehole inclination may only change quite slowly with depth. A standard practice in the industry is to assume that the borehole schematic follows a so-called minimum radius of curvature. While drilling the well, periodic measurements of inclination are passed to the surface. The inclination between two such measurements is determined by fitting an arc of a circle of fixed radius such that the inclinations at the ends of the arc match the measured inclinations. In effect, the wellbore schematic is that combination of arcs that has a fixed radius between each measurement of inclination. We may use this methodology in the derivation of the wellbore schematic from pressure.
The unknown parameters become a 1 , a 2 , n 1 and n 2 and a series of inclinations, θ(MD), where θ is the inclination angle and MD is the length of coil run into the well. The nonlinear estimation will then minimize the sum of Y(t) 2 +Z(t) 2 where Z(t) is a weighting term constraining the rate of change of θ. There are well-known techniques to constrain rate of change. One standard formula is the sum of the absolute value:
rate of change=|θ( MD ( j +1))−θ( MD ( j ))|
for a predetermined selection of depths MD( 1 ), MD( 2 ), . . . . A typical selection of depths would be fixed interval of 10 m or 30 ft along the length of the wellbore. The result of this optimization is not just the wellbore schematic. The parametric values in the friction expression are in themselves useful because they may give indications of viscosity and the nature of the flow—for example, the exponent of the flow is indicative of the flow profile, whether it is laminar or turbulent. See for example, Bird, et al., “ Transport Phenomena ”, Chapter 6, pp. 180-190, John Wiley & Sons (1960).
Once the wellbore schematic is estimated then the same information on the wellbore schematic and pressure of fluids may be used to analyze the annulus fluid around the coil. The pressure drop between the bottomhole and the wellhead is the sum of the hydrostatic and friction pressures in the annulus, plus the effect of the reservoir (e.g. whether it is causing a net increase in pressure in the annulus or a decrease). Also the hydrostatic pressure at a given depth may be subtracted from the annular bottomhole pressure to get directly the effect of the formation pressure (and the changes in that formation pressure vs. time). For example, if the tool is stationary then the hydrostatic pressure may be subtracted from pressure measurements during a fall-off and formation parameters may be estimated using standard well-testing techniques. If the tool is not stationary, then to be able to use such techniques requires subtracting of the varying hydrostatic pressure versus depth. Interestingly, if there is a small error in the input fluid density then there will be a corresponding error in estimated TVD, but this would not then translate into an error in the estimated hydrostatic versus depth.
It is important that the flow-rate be varied during the run in the well. If a fixed flow-rate is used then deriving the parameters a 1 , a 2 , n 1 and n 2 will be very unstable.
Note that there is a significant advantage in transmitting the bottom-hole pressure in real-time because then the wellbore schematic may be determined without having to extract the coiled tubing.
Further, note that in a typical coiled tubing operation, there will be repeated passes through the wellbore, so that during the course of the operation, the uncertainty in the wellbore schematic will be removed. The surface operator (or his computer) will need to monitor which fluids are being pumped, which in turn would allow parameters a 1 , a 2 , n 1 , n 2 and density to vary from one fluid to the next.
Referring now to the drawing figures, FIG. 1 is a schematic cross-sectional view of a wellbore illustrating general configuration, measurements and parameters involved for one method of the invention.
Measurements (see FIG. 1 ):
Wellhead pressure: WHP, measured at surface at the flow exit.
Circulation pressure: P circ , measured at surface, inside the CT at the ‘in’ extremity.
Annulus bottom hole pressure: P an , measured in the wellbore, at the end of the CT string.
CT bottom bole pressure: P CT , measured inside the CT, at the bottom end.
Parameters:
Total CT string length: L T
CT length in hole: MD
Wellbore, CT radii (resp. diameters): r w , r CT (resp. d w , d CT ).
Friction coefficient: f
annulus fluid velocity: υ an .
The four measured pressures are linked by the following relationships:
P an =WHP+F an +H an (1)
P CT =P circ −F CT +H CT (2)
P CT =P an +DP nozzle (3)
DP nozzle is the differential pressure across the nozzle fitted at the end of the CT.
Notations: F for friction pressure, H for hydrostatic pressure. The subscripts ‘an’ and ‘CT’ stand respectively for ‘in the annulus or wellbore’ and ‘inside the coiled tubing’.
With the annulus friction pressure—in theory calculable—and the measured annulus and wellhead pressures, the quantity of interest, the annulus hydrostatic pressure, is inferred from (1):
H an =P an −WHP−F an (1a)
The hydrostatic pressure is also:
H an =ρ an ·g·TVD (4)
wherein TVD is the vertical depth, equal to MD as defined above in a vertical well. We therefore obtain the average annulus fluid density ρ an :
ρ
an
=
H
an
g
·
TVD
(
4
a
)
Obtaining the annulus friction pressure:
The friction in the wellbore is given by (with the usual assumptions):
F an = f · ρ an · v an 2 · MD r w - r CT ( 5 )
Note: The density may vary along the annulus, i.e., ρ=ρ(MD). ρ an in (5) is the average annulus fluid density given by:
ρ an = ∫ ρ ( MD ) · ⅆ MD ∫ ⅆ MD ( 6 )
and the friction pressure is:
F an = ∫ f · ρ ( MD ) · v an 2 r w - r CT · ⅆ MD ( 7 )
Combining the two relations above leads to equation (5).
The annulus friction pressure is a function of the annulus fluid density, i.e., the friction term in (1a) cannot be accessed without knowing the density. An estimate of the density can be used in (5) to get the friction loss, and then re-adjusted at each computation cycle after the set of equations (1a, 4a) has been solved. The friction term could be very inaccurate, one of the reasons being that it requires the friction coefficient f, which has large uncertainties.
The following scheme gives the variations of the annulus fluid density without having to calculate the friction pressure.
Case 1: Vertical well.
Equation (5) may be re-written:
F an =MD ρ an fk geo υ 2 an (8)
where k geo is a constant that depends on the geometry of the system. Note that equation (8) is not specific to the vertical case where, as noted previously TVD is equal to MD.
From equations (1, 4, 8) one obtains equations (9) and (9a):
P
an
-
WHP
=
MD
·
ρ
an
·
g
·
(
1
+
f
·
k
geo
g
·
v
an
2
)
(
9
)
P
an
-
WHP
MD
=
ρ
an
·
g
·
(
1
+
f
·
k
geo
g
·
v
an
2
)
(
9
a
)
The difference between the downhole annulus pressure and the wellhead pressure is proportional to the hydrodynamic pressure and density for any given flow rate. It follows that:
Even without knowing the friction in the annulus, the measured quantity (P an −WHP)/MD gives the variations of the density in the annulus. With f*k geo known the method is quantitative (both f and k geo are accessible, an experimental method for estimating the product f*k geo is described further).
Case 2: Deviated well.
In a deviated well we lose the proportionality between H an and MD. Assuming a constant deviation, if m is the cosine (deviation angle), and reviewing FIG. 2 herein:
H an ρ an ·g·[MD 0 +m ·( MD−MD 0 )] (10)
and from equations (1, 8, and 10), equations 11 and 11a may be obtained:
P
an
-
WHP
=
ρ
an
·
(
f
·
k
geo
·
v
an
2
+
g
·
m
)
·
MD
+
ρ
an
·
g
·
(
1
-
m
)
·
MD
0
(
11
)
P
an
-
WHP
MD
=
ρ
an
·
(
f
·
k
geo
·
v
an
2
+
g
·
m
)
+
ρ
an
·
g
·
(
1
-
m
)
·
MD
0
MD
(
11
a
)
Equation (11) may be solved for ρ an , given the well configuration. Another option is a chart of (P an −WHP) vs. MD with a set of pre-defined constant-density lines.
Friction test, an experimental method for estimating the product f*k geo :
While in hole, a friction test could be performed based on equations (9) or (11).
Before starting cleaning, i.e., no particles in suspension, equations (9 or 11) may be solved for the quantity f*k geo which characterizes the friction. This must be done before reaching the treatment zone so as to have a density well defined (density of the injected fluid).
Interrupted Flow Test
While flowing, short pump interruptions (v an =0) will allow solving equations (9, 11) for “ρ an ” without the need of taking into account friction. Such pumping interruptions may only be possible when the particles' settling times are long enough, i.e., with gel fluids and the like.
Derivation of well deviation and TVD (cf FIG. 3 ).
The well has a vertical section of length MD 0 , the wellbore deviation is a function of the measured depth MD. The friction pressure is still given by (7):
F an = ∫ f · ρ ( MD ) · v an 2 r w - r CT · ⅆ MD ( 7 )
The hydrostatic pressure is:
H an =∫ρ( MD )· g ·cos [θ( MD )]· dMD (12)
From (1, 7, 12):
P an −WHP =∫ρ( MD )· g cos [θ( MD )]· dMD +∫ρ( MD )· f·k geo ν an 2 ·dMD (13)
Differentiating equation (13) with respect to MD one gets equation (14):
ⅆ ( P an - WHP ) ⅆ MD = ρ ( MD ) · g · cos [ θ ( MD ) ] + ρ ( MD ) · f · k geo · v an 2 ( 14 )
The left hand side of (14) is measured. Equation (14) may be solved for ρ(MD) given the well trajectory (i.e. cos [θ(MD)] vs. MD) or for cos [θ(MD) given the density (i.e. ρ(MD) vs. MD). After equation (14) is solved the TVD may be obtained through:
TVD =∫cos [θ( MD )]· dMD (15)
FIGS. 4( a, b, c ) illustrate an example of application of the method. In this example, given the diameter of the wellbore and fluid flow rate, the friction term is negligible compared to the hydrostatic term. The density, which is constant, is determined while in the vertical portion of the well.
In many cases, it is advantageous to drain a reservoir with a multiplicity of wellbore branches connected together downhole to a main trunk wellbore, in the similar way that the roots of a plant retrieve water from the soil. Such wellbores are referred to as multilaterals, with each branch being referred to as a lateral. In such circumstances, it is important to know which branch of the reservoir has been penetrated by the coiled tubing. Using one or more embodiments of the invention described herein, a wellbore schematic can be determined from parameters measured on the coiled tubing. The derived wellbore schematic can be compared to a schematic of the multilateral well, and thereby identify which of the laterals has been penetrated. Note that only an approximate schematic is needed of the overall multilateral reservoir. As the coiled tubing penetrates a particular lateral, then a more accurate description of the multilateral reservoir can be obtained. With the help of an entry sub at the end of the coiled tubing, it is possible to enter many, or all, the laterals and so obtain a complete multilateral schematic.
Knowing which lateral has been penetrated is also important to optimize the reservoir stimulation. For example, if a water is being produced out of one lateral and hydrocarbon out of a second, then the operator will desire to pump a stimulating fluid, such as acid, into the hydrocarbon-containing lateral, and the operator will desire to pump a non-stimulating or viscous fluid, such as a gel, into the water-containing lateral. If these fluids were to be pumped into the wrong laterals, then overall hydrocarbon recovery would be ruined. Similarly, if many laterals are penetrating hydrocarbon, then it will be efficient to add stimulating fluids to each lateral. If the coiled tubing should accidentally re-enter an already stimulated lateral, then it is disadvantageous to pump more stimulating fluid into that lateral. In this way, it can be seen that increasing knowledge of the wellbore schematic penetrated by the coiled tubing is a means to increase overall hydrocarbon productivity. The ability to selectively choose fluids is only one such example of how to use wellbore information to increase overall hydrocarbon productivity and other applications will be immediately apparent to those skilled in the art.
In certain embodiments of the invention communication from the communication line to a surface data acquisition system may comprise wireless telemetry. The surface data acquisition system need not be at the well site, for example it may be a networked system including a computer at the well site and a second system at some remote location. The data transmitted may optionally be used to control the operation, whereby the pump rate or the composition of a treatment fluid is adjusted based purely upon the downhole data collected and transmitted by the communication line, or from a combination of downhole data and surface measurements.
As used herein, “pumping” means using a “pumping system”, which in turn means a surface apparatus of pumps, which may include an electrical or hydraulic power unit, commonly known as a powerpack. In the case of a multiplicity of pumps, the pumps may be fluidly connected together in series or parallel, and the energy conveying the pumped fluid may come from one pump or a multiplicity. The pumping system may also include mixing devices to combine different fluids or blend solids into the fluid, and the invention contemplates using downhole and surface data to change the parameters of the fluid being pumped, as well as controlling on-the-fly mixing.
By the phrase “surface acquisition system” is meant one or more computers at the well site, but also allows for the possibility of a networked series of computers, and a networked series of surface sensors. The computers and sensors may exchange information via a wireless network. Some of the computers do not need to be at the well site but may be communicating via a communication system such as that known under the trade designation InterACT™ or equivalent communication system. In certain embodiments a communication line may terminate at the wellhead at a wireless transmitter, and the downhole data may be transmitted wirelessly. The surface acquisition system may have a mechanism to merge the downhole data with the surface data and then display them on a user's console. The surface acquisition system may also include apparatus allowing communication to the downhole sensors.
Data transmitted from the communication line may be used to monitor subsequent stages of reservoir or wellbore treatment. The data transmitted may optionally be used to control some or all of the treatment operation, whereby for example a pump rate or composition of a fluid being injected is adjusted based purely on the downhole data obtained by the communication line, or from a combination of downhole data and surface measurements. The downhole data transmitted may be that from one or more sensors attached to the end of one or more communication lines, and may supplement or be supplemented by a variety of other measurements. The data may be from a distributed section of a communication line such as distributed temperature along an optical fiber. The data collected may be stored on the acquisition system and the information used to optimize and/or model subsequent stimulation runs.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art may readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, no clauses are intended to be in the means-plus-function format allowed by 35 U.S.C. §112, paragraph 6 unless “means for” is explicitly recited together with an associated function. “Means for” clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. | Methods are described for determining or estimating a wellbore schematic, one embodiment comprising running one or more measured distances of coiled tubing into a wellbore while pumping a fluid at varying flow rates through the coiled tubing, and calculating true vertical depth of the wellbore using pressure and flow rate data of the fluid. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It may not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b). | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to memory apparatus for use in a data processing system and particularly to the mounting of magnetic head arms in a rigid magnetic disc memory apparatus.
2. Description of the Prior Art
Magnetic disc drive memory apparatus usually have one or more rigid rotatable discs coated with a material which permits storage of data on and retrieval of data from the disc surface. To accomplish the read and write operations a recording head is positioned adjacent to the surface of each disc. During operation of the memory apparatus, the heads are moved parallel to the surfaces of the discs to position the read/write gaps of the heads adjacent to the appropriate location on the disc surface where a read or write transaction is to take place.
A common type of rigid magnetic disc unit is the "IBM 3350" style disc drive. This unit has a plurality of magnetic rigid discs co-mounted about a central, spinable shaft. Each disc has one or more magnetic heads associated with it. The heads are mounted on head arms, up to four heads per arm. The head arms are mounted in a channel of the magnetic head carriage such that the head arms move in unison across the surface of the discs as the carriage moves. A typical head arm for use in this type of unit is the "Model 335004" manufactured by Applied Magnetics.
In the prior art the carriage channel is difficult and costly to manufacture in that the prior art method of accommodating the head arms requires a substantial amount of machining to be performed on the channel. In addition, the prior art technique used for mounting the magnetic head arms in the channel requires slits to be made in one of the channel walls. The channel structure is weakened by the presence of the slits and unfavorable resonant frequencies can result, causing degraded head arm performance.
The present invention relates to a novel apparatus for mounting of magnetic head arms in a magnetic disc unit which is free of the above-mentioned disadvantages and problems.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to apparatus for mounting magnetic head arms in a magnetic disc memory. In a preferred construction of the invention, the head carriage has a head arm mounting channel, the channel having structure mounted therein for aligning and supporting each magnetic head arm in its proper location. Each magnetic head arm is clamped rigidly in place in the channel by a slug acting in concert with structure for applying force to the slug.
It is a further feature of this invention that the magnetic head arms are aligned and supported by ladder elements slidably mounted in grooves in the channel walls.
It is a further feature of this invention that each slug is movably mounted through an aperture in a wall of the channel.
It is a further feature of this invention that the structure for applying force to each slug is a bolt which is mounted through an aperture in the channel wall opposite from the slug and which engages a threaded hole in the slug.
It is a further feature of this invention that the channel wall opposite from the slug has an arcuate groove therein at the point of magnetic head arm contact whereby the forces resulting from clamping of the head arm against the wall are properly distributed.
It is a further feature of this invention that the aperture through which the bolt is mounted is counterbored.
It is an advantage of this invention that the head arm mounting channel of the carriage requires substantially less machining during manufacture than does the prior art channel.
It is a further advantage of this invention that this apparatus for mounting the head arms does not cause channel deformation.
Other features and advantages of the present invention will be understood after referring to the detailed description of the preferred embodiment and to the appended drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of several major elements of a magnetic disc unit;
FIG. 2 is a perspective view of an illustrative embodiment of the present invention including a segment of the magnetic head carriage showing head arm mounting elements in an exploded position;
FIG. 3 is a perspective view of a segment of the magnetic head carriage of FIG. 2 viewed from a different position to facilitate display of certain features;
FIG. 4 is a top view of the magnetic head carriage of FIG. 2 showing details of the apparatus after head arm mounting;
FIG. 5 is a cross sectional view of the head carriage showing details of the apparatus after head arm mounting;
FIG. 6 shows an alternate embodiment of the present invention; and,
FIG. 7 shows another alternate embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a side view of a magnetic disc unit is presented. Magnetic discs 10 are mounted on shaft 11. Magnetic head arms 20 are mounted in channel 12 of movable carriage 13 and are positioned in relation to discs 10 by motor 14 as required to accomplish read/write operations at various locations on a disc surface. Circuitry and wiring (not shown) for performing the read/write operations is attached to and extends from magnetic head arms 20.
Referring now to FIG. 2, the mounting channel and head arm mounting elements are shown. Each head arm 20 has an associated clamping slug 32, aperture 43, bolt 30, aperture 44, aperture 45a and aperture 46a. These elements operate in conjunction with features of mounting channel 12 (described below) to accomplish mounting of head arms 20 to carriage 13.
Referring to FIGS. 2 through 5 in concert, a preferred embodiment of the invention is shown. It can be seen that a cross-section of the head arm mounting channel is substantially U-shaped, having a back wall and two substantially parallel side walls. Substantially identical ladder elements 45 and 46 are slidably mounted in channel grooves 47. Protruding sections 45c and 46c rest upon carriage surface 48 when ladder elements 45 and 46 are mounted in the channel and hold ladder elements 45 and 46 in the proper vertical postion. Ladder elements 45 and 46 have a like number of aligning apertures 45a and 46a therein. Each magnetic head arm 20 is mounted through an aperture 45a and 46a and is supported and aligned in the channel by surfaces 45b and 46b. Clamping slug 32 is mounted through aperture 43 such that slug 32 protrudes into the channel. Bolt 30 is mounted through aperture 44 in the channel wall and mates with threaded hole 34 in slug 32. As bolt 30 is turned, slug 32 is drawn toward magnetic head arm 20 causing surface 33 of slug 32 to be pressed against angled surface 23 of magnetic head arm 20, thereby urging magnetic head arm 20 into contact with surfaces 45b and 46b of ladder elements 45 and 46 and with arcuate groove 41. Groove 41 is located such that only edge 50 (i.e. junction of surfaces 24 and 25) of head arm 20 comes into contact with the channel wall as slug 32 applies clamping force to the head arm. At the point of contact between the head arm and the wall, the curvature of groove 41 is such that head arm 20 is urged downward against surfaces 45b and 46b of ladder elements 45 and 46. It can therefore be seen that in addition to the horizontal components of clamping force, both slug 32 and groove 41 create vertical force components which hold the head arm in contact with ladder elements 45 and 46. Head arm 20 is thereby firmly attached to carriage 13 and undesired head arm movement is substantially precluded. Groove 40 in the channel wall accommodates electrical wiring 22 of magnetic head arm 20 so as to prevent abrasion of wiring 22 during carriage movement, and aperture 44 is counter bored such that head of bolt 30 does not protrude beyond the outer surface of the channel wall after the head arm is mounted.
Referring to FIG. 6, a perspective view of a segment of the head carriage similar to the view in FIG. 2 is presented. This is one alternate embodiment of the mounting means. The supporting and aligning function of ladder elements 45 and 46 is performed by pins 61 which are press fitted through apertures 62 in both channel walls such that pins 61 protrude into the channel and magnetic head arm 20 rests thereon.
Referring to FIG. 7, another perspective view of a segment of the head carriage similar to the view in FIG. 2 is presented. This is another alternate embodiment of the mounting means. Countersunk aperture 44 has been replaced by aperture 53, which is of substantially the same size as aperture 43. In this figure, bolt 30 passes through aperture 51 in slug 50 which mounts through aperture 53. Bolt 30 then mates with aperture 34 in slug 32. Slug 50 differs from slug 32 only in that aperture 51 is smooth while aperture 34 is threaded. The need for grooves 41 in one channel wall has been eliminated because head arm 20 is clamped between the two slugs, rather than being pressed against the wall. As bolt 30 is turned, slug 32 is drawn toward slug 50, thereby forcing head arm 20 into contact with slugs 32 and 50 and with pins 31.
The present invention may be embodied in yet other specific forms without departing from the spirit or essential characteristic thereof. Two possible alternative embodiments have been shown, therefore, the present embodiments are to be considered in all respects as illustrations and not restrictive. All changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. | An apparatus for mounting of magnetic head arms on a head carriage in a disc drive memory system. The magnetic head arms are held firmly in place by clamping slug and bolt assemblies which are mounted through the head arm channel walls. The apparatus includes elements mounted in the head arm channel of the carriage for aligning and supporting the magnetic head arms in the channel. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority from U.S. provisional patent application Ser. No. 60/162,131, filed Oct. 29, 1999. The disclosure of the above-referenced provisional patent application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a liquid oxygen storage and delivery system.
2. Description of the Background Art
Therapeutic oxygen is the delivery of relatively pure oxygen to a patient in order to ease pulmonary/respiratory problems. When a patient suffers from breathing problems, inhalation of oxygen may ensure that the patient is getting an adequate level of oxygen into his or her bloodstream.
Therapeutic oxygen may be warranted in cases where a patient suffers from a loss of lung capacity for some reason. Some medical conditions that may make oxygen necessary are chronic obstructive pulmonary disease (COPD) including asthma, emphysema, etc., as well as cystic fibrosis, lung cancer, lung injuries, and cardiovascular diseases, for example.
Related art practice has been to provide portable oxygen in two ways. In a first approach, compressed oxygen gas is provided in a pressure bottle, and the gas is output through a pressure regulator through a hose to the nostrils of the patient. The bottle is often wheeled so that the patient may be mobile. This is a fairly simple and portable arrangement.
The drawback of compressed, gaseous oxygen is that a full charge of a bottle that is portable does not last a desirable amount of time.
In order to get around this limitation, in a second approach a related art liquid oxygen (LOX) apparatus has been used wherein LOX is stored in a container and the gaseous oxygen formed from the LOX is inhaled by the patient.
The related art LOX apparatus enjoys a longer usable charge than the compressed gas apparatus for any given size and weight, but has its own drawbacks.
Related art LOX systems typically include a stationary storage container located in a patient's home and a portable unit that the patient uses outside the home. The stationary storage container must be periodically refilled with LOX by a distributor.
A significant percentage of the cost of having a LOX system is in the cost of frequent recharging trips by the LOX distributor. A distributor may have to make weekly recharge trips to a patient's home, or even more frequently, to recharge the patient's LOX system. There thus is a need in the art to cut deliveries or cut costs in other ways.
The main drawback of the related art is that considerable waste occurs. One source of waste is that prior art devices provide continuous flow. Also, in the related art, the portable unit may be filled with LOX and used for normal activities and movement. When the patient is done using the related art portable unit, remaining LOX left within the related art portable unit is vented, wasting any remaining oxygen. Because the LOX continues to convert to gaseous oxygen when not being withdrawn, venting is provided for in both the stationary and portable related art units. When the pressure in the related art stationary unit increases beyond a certain point (such as when the related art portable unit is being used), the related art stationary unit must be vented.
There remains a need in the art, therefore, for an improved LOX storage and delivery system, with less gas consumption and requiring fewer deliveries of LOX to the patients home.
SUMMARY OF THE INVENTION
A high-efficiency liquid oxygen (LOX) storage/delivery system is provided according to a first aspect of the invention. The high-efficiency liquid oxygen (LOX) storage/delivery system may include a primary reservoir LOX storage/delivery apparatus comprising a primary reservoir LOX container and a portable LOX/delivery apparatus including a portable LOX container. The primary reservoir LOX apparatus includes a main LOX transfer connector connected to the primary reservoir LOX container for inputting LOX into the primary reservoir LOX container and for outputting LOX from the primary reservoir LOX container to the portable LOX container, and a main-unit oxygen gas transfer connector for transferring oxygen gas from the primary reservoir LOX container. A primary reservoir indicator device may be connected to the primary reservoir LOX container for indicating the LOX contents of the primary reservoir LOX container. A main-unit primary relief valve is connected to the primary reservoir LOX container for venting oxygen gas out of the primary reservoir LOX container when pressure of oxygen gas in the primary reservoir LOX container reaches a predetermined level for the primary reservoir container. The portable LOX apparatus includes a portable-unit LOX transfer connector connected to the portable LOX container and connectable to the main LOX transfer connector for transferring LOX to the portable container from the primary reservoir container, a portable-unit oxygen gas transfer connector for transferring oxygen gas from the portable LOX container to an oxygen gas delivery device for delivering oxygen gas to a patient, an inter-unit oxygen gas transfer connector for connecting the portable apparatus to the main-unit oxygen gas transfer connector for transferring oxygen gas from the primary reservoir container to the portable apparatus, and a portable-unit primary relief valve connected to the portable LOX container for venting oxygen gas out of the portable LOX container when pressure in the portable LOX container reaches a predetermined level for the portable container. When the inter-unit oxygen gas transfer connector of the portable container is connected to the main-unit oxygen transfer connector of the primary reservoir container, oxygen gas can be transferred from the portable container to the oxygen gas delivery device while oxygen gas is transferred to the portable container from the primary reservoir LOX container.
A method for utilizing a high-efficiency liquid oxygen (LOX) storage/delivery system is provided according to a second aspect of the invention. One method comprises connecting the inter-unit oxygen gas transfer connector of a portable container to the main-unit oxygen transfer connector of a primary reservoir container, and withdrawing oxygen gas from the portable container through the portable-unit oxygen gas transfer connector while oxygen gas is transferred to the portable apparatus and to the patient from the primary reservoir container through the main-unit oxygen transfer connector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows one embodiment of a high efficiency LOX system of the present invention, and illustrates how the primary reservoir and portable LOX storage/deliver apparatus may be interconnected;
FIG. 2 schematically shows detail of one embodiment of the primary reservoir LOX storage/delivery apparatus;
FIG. 3 schematically shows detail of one embodiment of the portable LOX storage/delivery apparatus;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows one embodiment of a high efficiency LOX system 100 of the present invention. The LOX system 100 includes a primary reservoir LOX storage/delivery apparatus (primary reservoir apparatus) 120 and a portable LOX storage/delivery apparatus (portable apparatus) 160 . An umbilical conduit 110 may extend between an inter-unit oxygen gas transfer connector 190 of the portable apparatus 160 and a main-unit oxygen gas transfer connector 213 of the primary reservoir apparatus 120 , and may be used to transfer gaseous oxygen therebetween. An oxygen delivery device 90 , such as a mask or nasal tubes or cannulas may be attached to either apparatus in order to deliver gaseous oxygen to a patient. Alternatively, the inter-unit oxygen gas transfer connector 190 may be directly connected to the main-unit oxygen gas transfer connector 213 .
Because LOX transforms from a liquid to a gas as heat is added, related art LOX systems have typically relied on venting of excess gaseous pressure to maintain acceptable internal pressure levels. The result is a higher cost for the health care provider. Pressure control of the portable apparatus 160 and the primary reservoir apparatus 120 is of great importance, as keeping pressures down yields a safe, light weight, economical system through the reduction or elimination of venting. The present invention achieves such economy by balancing use of the primary reservoir apparatus 120 and portable apparatus 160 so that internal pressures do not build up to a point where either apparatus must be excessively vented. The LOX system 100 therefore allows usage cycles that make possible efficient LOX use without excessive venting.
The primary reservoir apparatus 120 can be of any usable size for storage and delivery of LOX over a desired time period. Suitable units in accordance with the present invention can hold from 20-60 or more liters of LOX. In accordance with one embodiment, a primary reservoir container holding about 36 liters (about 85 pounds) of LOX is provided. In a second embodiment, a primary reservoir container holding about 43 liters (about 110 pounds) of LOX is provided.
The primary reservoir apparatus 120 includes the main LOX storage and container. The LOX may be transferred from the primary reservoir apparatus 120 to the portable apparatus 160 as needed to charge the portable apparatus 160 for mobile use. The primary reservoir apparatus 120 is intended to hold a sufficiently large charge so that the primary reservoir apparatus 120 can recharge the portable apparatus 160 on a substantially daily basis for a substantially long period of time, e.g., up to about one month or more. This can reduce recharge costs by up to seventy-five percent or more over the related art.
The portable apparatus 160 preferably is about 3.5 pounds fully charged with LOX and about 2.5 pounds empty, is much smaller and lighter than the primary reservoir apparatus 120 , and may provide gaseous oxygen to the patient while being carried by the patient.
In use, the primary reservoir apparatus 120 is charged with LOX. The patient may use gaseous oxygen from the primary reservoir apparatus 120 directly via the main-unit oxygen gas transfer connector 213 , or may transfer LOX to the portable apparatus 160 wherein the patient may withdraw gaseous oxygen from the portable apparatus 160 . The portable apparatus 160 allows the patient mobility outside the home, while the umbilical conduit 110 , which may be up to 50-100 feet in length or longer, allows the patient to connect the portable apparatus to the main reservoir container to conserve LOX.
The inter-unit oxygen gas transfer connector 190 may be connected to the main-unit oxygen gas transfer connector 213 of the primary reservoir apparatus 120 to allow oxygen gas withdrawal alternatively from either the portable apparatus 160 or the primary reservoir apparatus 120 , or simultaneously from both.
FIG. 2 shows detail of one embodiment of the primary reservoir apparatus 120 . The primary reservoir apparatus 120 includes a primary reservoir container assembly 205 , a main LOX transfer connector 209 , a main-unit oxygen gas transfer connector 213 , and a main-unit primary relief valve 257 . In the embodiment shown, a primary indicator device 274 also is included.
The primary reservoir container assembly 205 includes an outer container 223 , an inner primary reservoir LOX container 226 spaced apart from the outer container 223 , insulation 229 located between the outer container 223 and the inner container 226 , a molecular sieve 231 , and a vacuum plug 235 . The space between the outer container 223 and the inner container 226 is preferably evacuated to at least a partial vacuum in order to minimize heat transfer to the LOX inside the inner container 226 .
The primary reservoir LOX container assembly 205 also includes an outlet port 238 , through which passes a neck conduit 242 . The neck conduit 242 extends a short distance into the inner container 226 , and is employed for gaseous oxygen withdrawal from the primary reservoir LOX container 226 . Inside the neck conduit 242 is a fill conduit 244 , preferably concentric with the neck conduit 242 . The fill conduit 244 may be used to fill the primary reservoir LOX container 226 with LOX. Inside the fill conduit 244 is a liquid withdrawal conduit 247 , preferably concentric with the fill conduit 244 . The liquid withdrawal conduit 247 may be used to withdraw LOX from the primary reservoir LOX container 226 .
Above the outlet port 238 of the primary reservoir LOX container 205 the neck conduit 242 splits into two independent conduits. A main-unit vent valve conduit 250 leads to a main-unit vent valve 251 which is openable for filling inner container 226 with LOX through the main LOX transfer connector 209 . When filling inner container 226 with LOX, main unit vent valve 251 is opened until liquid exits valve 251 , indicating that container 226 is filled with LOX.
Relief/economizer conduit 255 leads to a main-unit primary relief valve 257 and an economizer valve 261 . The main-unit primary relief valve 257 is provided for relieving excess internal gas pressure from the primary reservoir LOX container 226 if the internal gas pressure exceeds a predetermined limit, e.g., 55 psi. Conduit 255 also leads to a main-unit secondary relief valve 258 , which can be set at the same or a higher level (e.g., 10-20% higher) than the main-unit primary relief valve, and is a back-up thereto in case of failure thereof.
Conduit 255 further leads to an economizer valve 261 , the purpose of which will be explained below.
Above the neck conduit 242 extends the fill conduit 244 , which extends upward to the main-unit LOX transfer connector 209 . Between the top of the neck conduit 242 and the main-unit LOX transfer connector 209 is a tee 263 , where the liquid withdrawal conduit 247 exits the fill conduit 244 . After exiting the fill conduit 244 , the liquid withdrawal conduit 247 encounters a second tee 264 that joins the liquid withdrawal conduit 247 with an economizer conduit 266 in advance of a warming coil 269 . The economizer conduit 266 connects the economizer valve 261 with warming coil 269 . Gaseous oxygen passes through economizer valve 261 when the economizer valve is open. In order to conserve LOX, the economizer valve 261 can be set at any suitable level below the primary and secondary relief valve settings, so that gaseous oxygen will pass through the economizer valve 261 into the warming coil 269 before such gaseous oxygen is vented through the main-unit primary relief valve 257 or the main-unit secondary relief valve 258 . One suitable setting for the economizer valve 261 is 22 psi. The liquid withdrawal conduit 247 supplies LOX to the warming coil 269 , while the economizer conduit 266 supplies gaseous oxygen withdrawn by way of the relief/economizer conduit 255 . In the warming coil 269 the withdrawn LOX and gaseous oxygen is warmed by exposure to room temperature, speeding the liquid-to-gas transformation. It should be noted that the inside diameter of the warming coil 269 may be greater than the inside diameter of the liquid withdrawal conduit 247 , allowing the LOX to expand as it warms up and transforms from a liquid phase to a gaseous phase. However, the inside diameter of the liquid withdrawal conduit 247 preferably is sized so that when the economizer valve 261 is open, gas flow through line 266 is favored to warming coil 269 over liquid withdrawal through conduit 247 . In the embodiment shown, the warming coil 269 is connected to a pressure regulator 271 which can maintain a desired operating pressure at a main-unit oxygen gas transfer connector 213 .
In the embodiment shown, the primary reservoir LOX container 205 includes a primary indicator device 274 that indicates a LOX level in the primary reservoir LOX container 226 . The primary indicator device 274 is connected to a bottom portion of the primary reservoir LOX container 226 via a high pressure sensing conduit 279 . The primary indicator device 274 may be interconnected to a pressure gauge 217 . The pressure gauge 217 gives a visual readout of an internal gas pressure for the primary reservoir LOX container 226 , and may be, for example, a mechanical pressure gauge. The pressure gauge 217 is connected to conduit 255 via a low pressure sensing conduit 277 .
In use, LOX may be added to or withdrawn from the primary reservoir LOX container 226 through the main-unit LOX transfer connector 209 and the fill conduit 244 . The main-unit oxygen gas transfer connector 213 may be used to withdraw gaseous oxygen for use. The gaseous oxygen is provided to the main-unit oxygen gas transfer connector 213 from the economizer valve 261 and/or by conversion of LOX to gas through the liquid withdrawal conduit 247 , both through the warming coil 269 .
FIG. 3 shows detail of one embodiment of the portable apparatus 160 . The portable apparatus 160 includes a portable LOX container 302 , a portable-unit LOX transfer connector 304 , a portable-unit oxygen gas transfer connector 384 , an inter-unit oxygen gas transfer connector 190 , and a portable-unit primary relief valve 315 .
The portable container assembly 302 includes an outer container 318 , an inner portable LOX container 319 spaced apart from the outer container 318 , a fill conduit 322 , a liquid withdrawal conduit 326 , a vacuum plug 328 , and a multi-lumen annular conduit 331 . The space between the outer container 318 and the inner container 319 is preferably evacuated to at least a partial vacuum in order to minimize heat transfer to the LOX inside the inner container 319 .
LOX may be introduced into the portable LOX container 319 through the portable-unit LOX transfer connector 304 and the fill conduit 322 . The portable-unit LOX transfer connector 304 may be connected to the main-unit LOX transfer connector 209 of the primary reservoir apparatus 120 , whereby the portable apparatus 160 may be filled with LOX from the primary reservoir apparatus 120 .
LOX may be withdrawn via the liquid withdrawal conduit 326 , and gaseous oxygen may be withdrawn via the neck conduit 331 .
A manifold 336 is connected to the neck conduit 331 , and splits the neck conduit 331 into a gaseous oxygen withdrawal conduit 339 and a vent conduit 341 . The vent conduit 341 may include a vent valve 344 . The vent valve 344 may be opened during filling of the portable LOX container 302 . When LOX emerges from the vent conduit 341 , it is a visual indication that the portable LOX container 319 is full.
In the embodiment shown, the liquid withdrawal conduit 326 passes through the manifold 336 and is connected to a liquid withdrawal warming coil 349 in which the LOX can transform to the gaseous phase. The liquid withdrawal warming coil 349 warms the LOX by exposure to room temperature, speeding the liquid-to-gas transformation. It should be noted that the inside diameter of the liquid withdrawal warming coil 349 may be greater than the inside diameter of the liquid withdrawal conduit 326 , allowing the LOX to expand as it warms up and transforms from a liquid phase to a gaseous phase.
The gaseous oxygen withdrawal conduit 339 connects with a gas withdrawal warming coil 352 . The gas withdrawal warming coil 352 warms the gaseous oxygen before delivery to an oxygen user.
Connected to the gas withdrawal warming coil 352 is a portable-unit primary relief valve 315 . The portable-unit primary relief valve 315 is capable of opening and relieving a gaseous oxygen pressure in the portable LOX container 319 if the internal gas pressure exceeds a predetermined level, e.g., 27 psi.
An economizer valve 356 connects the gas withdrawal warming coil 352 with conduit 380 containing gaseous oxygen from liquid withdrawal warming coil 349 . The portable-unit economizer valve 356 can be set at any suitable level below the portable-unit primary relief valve 315 , such as 22 psi, and allows gaseous oxygen from coil 352 to pass into line 380 when the pressure of the gaseous oxygen in the portable LOX container 319 exceeds the predetermined threshold level, e.g., 22 psi. In preferred embodiments, the inside diameter of the liquid withdrawal conduit 326 is sized so that when the portable-unit economizer valve 356 is open, gas flow through line 339 is favored over liquid flow through conduit 326 . This permits gaseous oxygen from the gaseous head-space in portable container 319 to pass to the patient without the need to waste through the portable-unit primary relief valve 315 . The portable-unit economizer valve 356 thus balances gaseous and liquid oxygen withdrawal from the portable LOX container 319 , and outputs a resulting gaseous oxygen to a conduit 309 . A portable-unit secondary relief valve 382 is provided as a back-up unit to the portable-unit primary relief valve 315 , and can be set at the same or a higher level than the portable-unit primary relief valve, and is a back-up thereto in case of failure thereof.
Although the function of the economizer valves of the present invention has been described above with reference to preferred embodiments, other configurations, utilizing operating systems of any suitable pressure, will fall within the scope of the present invention. For example, with systems operating at 20 psig, an economizer valve may be set at any suitable setting such as between 19.5 psig and 22 psig. Alternatively, for systems having operating pressures at about 50 psig, economizer valves having settings, for example, between 48 psig and 55 psig can be utilized. Corresponding primary relief setting for a 20 psig system can, for example, be between 21 psig and 24 psig. Corresponding primary relief settings for a 50 psig system can, for example, be between about 50 psig and 58 psig. However, these configurations are merely exemplary, and other configurations can be utilized in accordance with the present invention.
The gaseous oxygen from the conduit 309 may be delivered to a demand flow control device 360 , which also may receive gaseous oxygen from the primary reservoir apparatus 120 via the inter-unit oxygen gas transfer connector 190 . A check valve 363 may be included between the conduit 309 and the inter-unit oxygen gas transfer connector 190 to prevent backflow of gaseous oxygen from the portable apparatus 160 to the primary reservoir apparatus 120 .
The demand flow control device 360 is for adjustment of gas flow through a portable-unit oxygen gas transfer connector 384 a to an oxygen delivery device 90 for delivery of gaseous oxygen to a patient.
Gaseous oxygen is provided to the patient through the portable-unit oxygen gas transfer connector 384 a , either from the portable unit, or from the main reservoir unit through connector 190 .
In preferred embodiments, the demand flow control device 360 can be connected to a gas conserving device 390 . A known conserving device is disclosed in U.S. Pat. No. 5,360,000.
In the embodiment shown, a gas transfer connector system 384 a and 384 b is utilized, so that when the patient exhales, flow to the oxygen delivery device 90 is stopped, and gas accumulates in the conserving device 390 . When the patient inhales, a puff (bolus) of oxygen gas is delivered to the patient from conserving device 390 , thereby further preventing waste of gaseous oxygen, followed by an even flow of gaseous oxygen, which then is stopped again when the patient exhales.
Use of a conserving device 390 with the portable apparatus of the present invention connected to the primary reservoir apparatus 120 through connector 190 results in tremendous savings and LOX conservation.
A method of utilizing the high-efficiency LOX storage/delivery system 100 of the present invention is disclosed. The method uses an umbilical conduit 110 to economize oxygen use by a patient and balance use of the primary reservoir apparatus 120 and portable apparatus 160 so that excess oxygen venting is avoided.
The main-unit oxygen gas transfer connector 213 is connected to the inter-unit oxygen gas transfer connector 190 , e.g., by umbilical conduit 110 . The connection allows gaseous oxygen to flow from the primary reservoir apparatus 120 to the portable apparatus 160 . The gaseous oxygen from either the primary reservoir LOX storage delivery apparatus 120 or the portable apparatus 160 may be provided to the patient, depending on which has the higher gas pressure.
The umbilical conduit 110 may be a flexible conduit (such as a hose, for example) to give the portable apparatus 160 mobility while yet being connected to the primary reservoir apparatus 120 . In this hookup, the oxygen deliver device 90 is connected to the demand flow control device 360 in order to provide gaseous oxygen to the patient.
The method may utilize a filling/using cycle of the portable apparatus 160 . The method of filling/using of the present invention avoids or reduces unnecessary venting of either the portable apparatus 160 or the primary reservoir apparatus 120 .
Gaseous oxygen is withdrawn from the primary reservoir 120 for a withdrawal time period, which preferably is at least 5 hours per day, more preferably about 10 hours per day or more. The withdrawal of gaseous oxygen from the primary reservoir apparatus 120 may be through oxygen delivery device 90 either connected directly to-connector 213 , or connected to connector 384 of the portable apparatus with connector 190 of the portable apparatus connected to the main reservoir apparatus. This gaseous withdrawal time period hook-up to the primary reservoir apparatus 120 permits withdrawal of gaseous oxygen from the primary reservoir LOX container without internal pressure in the primary reservoir LOX container reaching excess levels requiring venting. This conserving measure, in conjunction with economizer valve 261 (and economizer valve 356 if the portable unit is hooked-up), enables oxygen withdrawal without wasteful venting.
After the above-discussed withdrawal time period, the portable apparatus 160 may be filled with LOX from the primary reservoir apparatus 120 and disconnected, for example, if the patient wishes to go outside the home.
In preferred embodiments, the portable LOX container holds about 1 pound of LOX, which, when utilized with the portable LOX/delivery apparatus of the present invention, can last approximately 10 hours at a typical patient use/withdrawal rate of about 2 liters per minute.
During withdrawal of gaseous oxygen from the primary reservoir LOX apparatus, oxygen gas pressure in the primary reservoir LOX apparatus is reduced to a level at which the economizer valve is set (e.g., 22 psi) such that after the portable container is filled with LOX and disconnected from the primary reservoir LOX apparatus, pressure may increase within the primary reservoir container for a gas pressurizing period within a range of 5-15 hours per day, e.g., about 10 hours per day, to a pressure of, for example, about 50 psi without LOX or oxygen gas being withdrawn from the primary reservoir container and without oxygen gas being vented from the primary reservoir container during the gas pressurizing period.
When the patient returns home prior to complete withdrawal of oxygen gas from the portable LOX container, the inter-unit oxygen gas transfer connector of the portable LOX container is connected to the main-unit oxygen transfer connector of the primary reservoir LOX container, and oxygen gas, may be withdrawn from the portable LOX container or the primary reservoir LOX container while oxygen gas may be transferred to the portable LOX apparatus from the primary reservoir LOX container through the main-unit oxygen transfer connector, depending on the pressure differential between the containers.
In accordance with one embodiment, during the withdrawal period, the inter-unit oxygen gas transfer connector of the portable LOX container is connected to the main-unit oxygen transfer connector of the primary reservoir LOX container, and oxygen gas is transferred from the portable container to the oxygen gas delivery device alternately or concurrently with oxygen gas being transferred to the oxygen gas delivery device through, the portable LOX apparatus from the primary reservoir LOX container, thereby lowering gas pressure in the primary reservoir LOX container.
The present invention can provide significant savings as compared to. related art systems. For example, at a patient use rate of 2 liters per minute, related art systems utilize about 10 pounds LOX per day. The present invention can provide the same 2 liters per minute utilizing about 2 pounds LOX per day, a savings of up to about 8 pounds LOX per day.
While the invention has been described in detail above, and shown in the drawings, the invention is not intended to be limited to the specific embodiments as described and shown. | A high-efficiency liquid oxygen, (LOX) storage/delivery system utilizes a portable LOX/delivery apparatus with a portable LOX container. A portable-unit LOX transfer connector is connected to the portable LOX container and is connectable to a main source of LOX in a primary reservoir LOX container. A portable-unit oxygen gas transfer connector is provided for transferring oxygen gas from the portable LOX container to an oxygen gas delivery device for delivering oxygen gas to a patient. An inter-unit oxygen gas transfer connector also is provided for connecting the portable apparatus to a stationary source of oxygen gas in the primary reservoir container, for transferring oxygen gas to the portable apparatus. A portable-unit primary relief valve is connected to the portable LOX container for venting oxygen gas out of the portable LOX container when pressure in the portable LOX container reaches a predetermined level. When the inter-unit oxygen gas transfer connector of the portable container is connected to the stationary source of oxygen in the primary reservoir container, oxygen gas can be transferred to the oxygen gas delivery device for delivery to the patient from the portable LOX container while oxygen gas is transferred to the portable container from the stationary source of gas in the primary reservoir LOX container. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to the technical field of nonferrous metal metallurgy, especially to a method for preparing a high-performance tantalum target material.
BACKGROUND OF THE INVENTION
[0002] Tantalum target materials are mainly applied in semiconductor film coating industry.
[0003] Physical vapor deposition (PVD), being one of the most essential processes in semiconductor chip production, is aimed at depositing a metal or a compound of a metal in a form of thin film onto a silicon wafer or other substrates, and finally forming complex wiring structure in semiconductor chip by cooperation of photolithography, etching and the like. PVD is completed via a sputtering machine station, and sputtering target materials are a very important and key consumptive material used in the process. Common sputtering target materials comprise highly pure tantalum, and also other nonferrous metals such as Ti, Al, Co, Cu or the like.
[0004] With increase of a wafer size from 200 mm (8 inches) to 300 mm (12 inches), the size of corresponding sputtering target material has to be increased so as to meet basic requirements of film coating by PVD. Meanwhile, when line width is decreased from 130-180 mm to 90-45 mm, the sputtering target material is changed from ultrahigh-purity Al/Ti system to ultrahigh-purity Cu/Ta system based on conductivity of a conductor and matching performance of a barrier layer. Ta target materials have increasing importance in the semiconductor sputtering industry, and demand therefore is bigger and bigger.
[0005] In prior art, tantalum target materials are mainly obtained by a process of cold rolling or cold forging. The texture components in the thickness direction of the target materials obtained are not uniform, which mainly embodies in texture (100) dominating in the upper and lower surfaces of the target materials but texture (111) dominating therebetween. Such target materials may be used on a machine station with low use requirements, but when they are used on a high-end machine station such as 12″ machine station, the inconsistent sputtering rate occurring is unacceptable.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to overcome the above-mentioned defects in prior art and to provide a process for preparing a high-performance tantalum target material which has uniform texture components in the thickness direction and has a dominant texture in the upper and lower surfaces. In addition, the process provides an even sputtering rate and meets requirements for use in high-end sputtering.
[0007] The present invention is designed based on the following principles.
[0008] The uniformity in thickness of a thin film on a silicon wafer after sputtering is very important to the final product, and it depends on the internal structure and the texture orientation of a tantalum target. A target material in which the crystal grains are uniform and fine and have approximately the same crystalline orientation enables sputtering rate of the crystal grains to be sputtered approaching to the same and the angular distribution trajectory of the sputtered atoms approaching to the same in sputtering, such that a coated layer with a uniform thin film thickness can be obtained and the material utilization ratio of the tantalum target can be increased greatly.
[0009] Therefore, the present invention provides the following technical solution.
[0010] A method for preparing a high-performance tantalum target material is characterized in that it comprises: first preparing a tantalum ingot into a forged blank by a process of cold forging in combination with hot forging; then rolling by a hot rolling process; and finally leveling, and blanking, cutting and performing surface treatment according to size of a finished product, so as to obtain the tantalum target material.
[0011] The above process of cold forging in combination with hot forging comprises: first performing primary forging to the tantalum ingot by the cold forging process, performing secondary forging by the hot forging process after pickling and heating treatment, and then performing tertiary forging by the hot forging process after pickling and heating treatment again.
[0012] The above cold forging process may be carried out by adopting cold forging processes that are known in the art, preferably swaging, with a forging ratio controlled within 25%-40%.
[0013] The above hot forging process is completed under hot forging conditions that are known in the art. Specifically, the process comprises upsetting and stretching a target blank at a temperature ranging from 800° C. to 1200° C., wherein the upsetting ratio is controlled within 55%-80%, and during stretching, a forging feed L=0.6-0.8 h, and a reduction Δh=0.12-0.15 h, wherein h represents the height of the blank before forging.
[0014] In one embodiment of the present invention, prior to upsetting and stretching, the target blank is first preheated to 200° C. and then coated with 1-3 mm thick glass frit thereon. The glass frit used in the present invention may be selected from glass frit used for hot compression, for example, those usable within the temperature range from 800° C. to 1200° C. In a preferred embodiment, glass frit with a particle size of 100 mesh is used. Commercial glass frit may also be used, e.g., type 844-7 spraying powder produced by Beijing Tianlichuang glass technology development co., ltd.
[0015] In one embodiment of the present invention, after the above tertiary forging, pickling and heating treatment are further needed, wherein a mixed acid is used in pickling, e.g., a mixed acid liquor of HCl and HF at a volume ratio of 5:2 or a mixed acid liquor of HCl, HF, and H 2 SO 4 at a volume ratio of 5:3:2. Other mixed acids with appropriate ratios may also be used. The heating treatment is carried out at a temperature being 25%-45% of the melting point of the tantalum material for a time ranging from 60 to 120 min, such as 70 min, 80 min, 90 min, 100 min or 110 min.
[0016] In another embodiment of the present invention, the above tantalum ingot is a cast ingot with a Ta content ≧99.95%, preferably ≧99.99% and a diameter from 160 mm to 300 mm.
[0017] In still another embodiment of the present invention, the step of rolling by a hot rolling process comprises: first preheating the forged blank to 900-1200° C., e.g., 950° C., 1000° C. or 1100° C., then rolling, and pickling until the tantalum metal is lustrous without mottles.
[0018] In a preferred embodiment, the total rolling ratio is controlled within 65%-85%, and the rolling temperature is controlled at 800-1200° C. The rolling adopts cross rolling with rolling direction turned clockwise by 45° for each time, in which the rolling ratio of the previous 8 passes is controlled within 50%-75%, and the subsequent rolling is mainly for compensating tolerance.
[0019] In a preferred embodiment, reheating in furnace is performed at a temperature of 900-1200° C., e.g., 950° C., 1000° C. or 1100° C. after rolling for every 2-6 passes during the above rolling.
[0020] In a preferred embodiment, prior to the rolling, surface of the blank is uniformly coated with 1-3 mm thick glass frit.
[0021] In a preferred embodiment, the pickling is carried out in a mixed acid liquor of HCI, HF, and H 2 SO 4 at a volume ratio of 5:3:2, and the pickling time is controlled to be 5 to 10 min.
[0022] In the present invention, tantalum ingot is forged by a process of cold forging in combination with hot forging, and the resulting forged blank is rolled by a hot rolling process so as to obtain a high-performance tantalum target material that meets requirements for use in high-end sputtering machine stations.
[0023] Particular technical features are as follows: 1. Forging by a process of cold forging in combination with hot forging can increase forging ratio, effectively trigger more slip systems, and effectively break the columnar crystal zones in the cast ingot, central equiaxial crystal zones, and fine crystal zones adjacent to edge of the tantalum ingot. Since the columnar crystal zones in the cast ingot, central equiaxial crystal zones, and fine crystal zones adjacent to edge of the tantalum ingot are effectively broken, metal flow in central part of the blank is increased, nonuniform degree of the central structure is remarkably reduced, and the original cast coarse-grain structure thereof is fully broken from multiple directions under action of forces in multiple directions. In this way, the forged plate blank obtains a structure with relatively uniform grains, and avoids presence of harmful structures such as “crystal zone” structure and coarse-grin structure subsequently remaining because the central part is not fully broken.
[0024] 2. Nonuniform distribution of deformation in height of section of a rolled part is closely related with the shape coefficient in a deformed zone. If the shape coefficient L(L=(RΔh) 1/2 /h) (wherein R is radius of roller; Δh is reduction; and h is average thickness) in the deformed zone is small, influence of outer end on the deformation process becomes prominent, and compressive deformation cannot go deep into inside of the tantalum blank, but limited in the region adjacent to the surface layer. At this time, the deformation in the surface layer is greater than that in the central layer, and metal flow velocity and stress distribution are not uniform. By hot rolling, the present invention can effectively enhance flowability of material and achieve rolling with a large shape coefficient in deformed zone. Rolling compressive deformation completely goes deep into inside of the tantalum blank such that the deformation in the central layer is equal to or slightly greater than the deformation in the surface layer, thereby to promote the plate blank to be rolled and deformed into a shape of “waist drum” rather than a shape of “hyperbola”. Rolling by such a method can effectively break coarse columnar grains remaining from the previous procedure, because this process can cause more dislocations accumulated along coarse grain boundaries, further effect uniformity and fineness in the grains of the plate blank, and promote grains to slip on plural slip surfaces (lines), which completes former treatment for subsequent heating treatment to from γ strong texture.
[0025] For the high-performance tantalum target material prepared by the method according to the present invention, firstly, it has uniform crystallization with grain size between 50 μm and 120 μm; and secondly, texture components where texture (110) dominates in the thickness direction of the target material are obtained, and they are uniform in the thickness direction. Compared with common tantalum target material, the high-performance tantalum target material not only achieves texture components where texture (110) dominates in the thickness direction of the target material, but also sets forth higher requirements for uniformity in the textures (a total proportion of three textures (111), (110) and (100) comprises between 40% and 50%), thereby ensuring a consistent sputtering rate during use.
[0026] In another aspect, the present invention relates to a high-performance tantalum target material prepared by the above method. In one embodiment, the tantalum target material has a tantalum content ≧99.99%. In another embodiment, the grain size of the tantalum target material is between 50 μm and 120 μm. In another embodiment, the texture is dominant in the thickness direction (110) of the tantalum target material, and a total proportion of three textures (111), (110) and (100) is between 40% and 50%.
[0027] In still another aspect, the present invention relates to use of the high-performance tantalum target material prepared according to the aforementioned methods in film coating of a semiconductor, in particular, in film coating by physical vapor deposition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The technical solutions and technical advantages of the present invention are illustrated below with reference to the drawings, in which
[0029] FIG. 1 shows the metallographic test result after forging according to cold forging method of the prior art;
[0030] FIG. 2 shows the metallographic test result after forging according to an embodiment of the present invention;
[0031] FIG. 3 shows schematic diagram of the metallographic test method for analyzing uniformity of the grain sizes in the thickness direction of the target material.
[0032] FIG. 4 shows the metallographic test result after rolling according to a method of the prior art.
[0033] FIG. 5 shows the metallographic test result after rolling according to one embodiment of the present invention.
[0034] FIG. 6 shows the texture test result after rolling according to cold rolling method of the prior art.
[0035] FIG. 7 shows the texture test result after rolling according to one embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0036] A method for preparing a high-performance tantalum target material according to a preferred embodiment of the present invention will be described below in details. The overall processing solution of the method is as follows:
[0037] tantalum ingot—primary forging—pickling—heating treatment—secondary forging—pickling—heating treatment—tertiary forging—pickling—heating treatment —rolling—pickling—heating treatment—leveling—blanking—cutting —surface treatment—checking of the finished product.
[0038] The specific solution is as follows: 1. Tantalum ingot: 160 mm≦diameter≦300 mm; chemical composition: Ta≦99.99%. 2. Primary forging: cold forging, adopting swaging process, in which tantalum ingot with a large diameter is forged with a forging ratio controlled within 25%-40%.
[0039] 3. Pickling: HCl:HF=5:2 (volume ratio), the pickling time is controlled to be 2-5 min, the treatment is mainly for removing surface impurities, and it is stopped till the luster of tantalum metal can be observed visually without mottles.
[0040] 4. Heating treatment: the heating treatment is carried out at a temperature being 25%-45% of the melting point of tantalum material for 60 min.
[0041] 5. Secondary forging: hot forging process is used. Specifically, it is first preheated to 200° C., then coated with 1-3 mm thick glass frit; subsequently, the target blank is heated to 800° C. to 1200° C., and subjected to primary upsetting and stretching, wherein the upsetting ratio is controlled within 55%-80%, and during stretching, the forging feed L=0.6-0.8 h (h represents height of the blank before forging), and the reduction Δh=0.12-0.15 h. To achieve a relatively uniform deformation, the feed position for the current compression should be staggered with the feed position for the previous compression during stretching. Standard gauge block is used as a cushion block to ensure uniformity and controllability in each reduction.
[0042] 6. Pickling: HCl:HF:H 2 SO 4 =5:3:2 (volume ratio), the pickling time is controlled within 5 to 10 min to remove surface impurities, and it is stopped till the luster of tantalum metal can be observed visually without mottles.
[0043] 7. Heating treatment: the heating treatment is carried out at a temperature being 25%-45% of the melting point of tantalum material for 60 min.
[0044] 8. Tertiary forging: hot forging is used. Specifically, it is first preheated to 200° C., then coated with 1-3 mm thick glass frit; subsequently, the target blank is heated to 800° C. to 1200° C., and subjected to secondary upsetting and stretching, wherein the upsetting ratio is controlled within 55%-80%. During stretching, the forging feed L=0.6-0.8 h (h represents height of the blank before forging), and the reduction Δh=0.12-0.15 h. To achieve a relatively uniform deformation, the feed position for the current compression should be staggered with the feed position for the previous compression during stretching. Standard gauge block is used as a cushion block to ensure uniformity and controllability in each reduction. In upsetting, the height is adjusted according to size of the finished product.
[0045] 9. Pickling: HCl:HF:H 2 SO 4 =5:3:2 (volume ratio), the pickling time is controlled within 5 to 10 min to remove surface impurities, and it is stopped till the luster of tantalum metal can be observed visually without mottles.
[0046] 10. Heat treatment: the heating treatment is carried out at a temperature being 25%-45% of the melting point of tantalum material for 60 min.
[0047] 11. The forged blank is preheated to 900° C. to 1200° C.
[0048] 12. Rolling, the thickness is controlled to be the thickness of the finished product required by customers plus a machining allowance of 2-4 mm.
[0049] 1) To reduce oxidation of materials during rolling, the blank is coated with glass frit on surface thereof before rolling, and coating of the glass frit shall be uniform with a thickness controlled within 1-3 mm.
[0050] 2) Total rolling ratio is controlled within 65%-85%.
[0051] 3) Reheating in furnace is required after it is rolled for every 2-6 passes. The heating temperature is the same as the temperature for preheating the blank, i.e. 900° C. to 1200° C.
[0052] 4) The temperature of the material is monitored in real time with a remote sensing thermometer during rolling. The rolling temperature should not be less than 800° C., and be controlled between 800° C. and 1200° C.
[0053] 5) Cross rolling is adopted, wherein rolling direction turns clockwise by 45° for each time. The rolling ratio of the first 8 passes is controlled within 50%-75%, and the subsequent rolling is mainly for compensating tolerance. The thickness tolerance of the same plate is controlled within 0.5 mm.
[0054] 13. Pickling is carried out in a mixed acid liquor of HCl, HF and H 2 SO 4 at a volume ratio of 5:3:2, and the pickling time is controlled between 5 min and 10 min to remove surface impurities, and it is stopped till the luster of tantalum metal can be observed visually without mottles.
[0055] 14. Heating treatment: the heating treatment is carried out at a temperature being 25%-45% of the melting point of tantalum material for 60 min.
[0056] 15. Leveling, the leveling temperature is 600° C. to 800° C.
[0057] 16. Blanking, an allowance of 5-10 mm is provided according to size of the finished product during blanking. 17. Cutting, the cutting is carried out according to size of the finished product. 18. Surface treatment: surface defects are removed by combination of mechanical finishing and artificial finishing.
[0058] 19. Checking of finished product: the target material is detected in grain size, outline dimension, surface roughness, and planeness (different customers have different requirements).
[0059] FIG. 1 shows the metallographic test after forging of the tantalum ingot according to cold forging method of the prior art;
[0060] FIG. 2 shows the metallographic test after forging of the tantalum ingot according to one embodiment of the present invention. In the embodiment according to the present invention, a tantalum ingot is forged by a process of cold forging in combination with hot forging, and the forged blank is subjected to the metallographic test, with results shown in FIG. 2 .
[0061] The results shown in FIG. 1 are compared with the results shown in FIG. 2 . FIG. 1 shows after forging according to the method of the prior art, the grain size of the forged blank is nonuniform, and phenomenon of evident delamination occurs. In contrast, as shown in FIG. 2 , the forged blank after forging according to the embodiment of the present invention has a uniform grain size and no evident delamination.
[0062] After the forged blank is rolled by hot rolling according to an embodiment of the present invention, the resultant target material is subjected to the metallographic test according to the test method shown in FIG. 3 , and uniformity of grain size in the thickness direction of the target material is analyzed.
[0063] As shown in FIG. 3 , the red region A is the region where metallograph is taken. Metallographs are taken continuously at a height of 1.5 mm for each time, and then the metallographs are spliced together in sequence.
[0064] FIG. 4 shows the metallographic test result of target material after the blank is rolled according to cold rolling process in the prior art.
[0065] FIG. 5 shows the metallographic test result of target material after the forged blank is hot rolled according to hot rolling process of the present invention.
[0066] By comparison, in the target material obtained by the method in the prior art, as shown in FIG. 4 , the grain size is nonuniform, phenomenon of delamination occurs, and the grain size in the central part is larger. However, in FIG. 5 , the target material obtained by the method of the present invention has uniform grain size.
[0067] In addition, the target material formed after hot rolling according to the method of the present invention is subjected to texture detection. Table 1 shows detection result data of the textures of the target material rolled according to the cold rolling process in the prior art. Table 2 shows detection result data of the textures of the target material rolled according to the method of the present invention. Average grain size and proportion of each of texture components (111), (110) and (100) that are detected at points (from the top down) taken at different parts of the target material with equal intervals are listed in the tables.
[0000]
TABLE 1
Detection result data of textures of the target
material rolled according to the prior art
Average grain
Texture
Texture
Texture
Part
size (μm)
{100}
{110}
{111}
From
1#
28.7 ± 21.7
17.8
11.7
12.3
top to
2#
32.5 ± 23.9
18.7
9.94
22.4
bottom
3#
31.6 ± 24
11.2
5.6
39.2
4#
35.1 ± 29.5
8.82
6.25
42.6
5#
30.5 ± 23.5
17.5
7.74
19
6#
25.8 ± 22.3
15.3
9.7
19.3
Whole
31.2 ± 25
14.8
8.43
26
[0000]
TABLE 2
Detection result data of textures of the target material
rolled according to the method of the present invention
Average grain
Texture
Texture
Texture
Part
size (μm)
{100}
{110}
{111}
From
1#
29.9 ± 19.8
9.56
19.1
12.9
top to
2#
27.5 ± 16.5
11.5
21.1
10.2
bottom
3#
29.4 ± 18.8
12.1
21.5
11.5
4#
32.9 ± 20.5
12
21.4
10.1
5#
33.4 ± 22
11.9
28.1
6.65
6#
31.2 ± 20.8
9.91
27
10.2
7#
31 ± 18.8
11.3
26
8.74
8#
33.8 ± 21
14.4
19.1
11.3
9#
38.2 ± 24.9
13.3
23
9.99
Whole
31.6 ± 20.6
11.7
22.9
10.3
[0068] FIG. 6 shows diagram of texture result of the target material rolled according to a method in the prior art; and FIG. 7 shows diagram of texture result of the target material rolled according to an embodiment of the present invention.
[0069] As can be seen from table 1 and FIG. 6 , in the target material cold rolled according to the method in the prior art, distribution of texture components is not uniform, and texture (111) is dominant and gradually increases from the surface to the central part of the target material. The total proportion of three textures (111), (110) and (100) is between 42% and 57%.
[0070] By analysis on the results shown in table 2 and FIG. 7 , it can be seen that in the tantalum target material rolled according to the method of the present invention, texture components are distributed uniformly, and texture (110) is dominant. The total proportion of three textures (111), (110) and (100) is between 42% and 48%.
[0071] Consequently, by treating the high-performance rolled blank via the hot rolling process according to the present invention, a uniform high-performance tantalum target material having texture components in which texture (110) dominates in the thickness direction of the target material and meeting requirements for use in high-end sputtering machine station. Compared with common tantalum target material, the high-performance tantalum target material not only achieves texture components where texture (110) dominates in the thickness direction of the target material, but also sets forth higher requirements for uniformity in the textures (the total proportion of three textures (111) (110) and (100) comprises between 40% and 50%), thereby ensuring a consistent sputtering rate during use.
[0072] The above merely demonstrates preferred embodiments of the present invention. It should be noted that several improvements and modifications may be made by an ordinary person skilled in the art without deviation from the principle of the present invention, and such improvements and modifications shall be regarded as falling within the protection scope covered by the present invention. | A method for preparing a high-performance tantalum target, a high-performance target prepared by the method, and a use of the high-performance target. The method for preparing the high-performance tantalum target comprises: firstly, preparing a tantalum ingot into a forging blank by a method of cold forging in conjunction with hot forging; then, rolling the forging blank by a hot rolling method; and finally, performing leveling, and performing discharging, milling and surface treatment according to a size of a finished product, so as to obtain the tantalum target. The tantalum target prepared by the method has uniform crystallization, with a grain size between 50 μm and 120 μm. A texture component where a texture (110) dominants in the thickness direction of the target is obtained. A total proportion of three textures (111), (110) and (100) is between 40% and 50%, ensuring a consistent sputtering rate of the tantalum target during use. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to automatic clothes drying machines and more particularly to a method and apparatus for operation of such a machine at dual energy input levels.
2. Description of the Prior Art
Operation of clothes drying appliances at different temperatures during a drying cycle is known in the art. A high level of temperature is generally employed for fast drying and a lower level is provided for efficient drying, utilized less power input. When dual heat operation is utilized, such as in U.S. Pat. Nos. 3,508,340 and 2,863,224, the period of high heat operation is followed by a period of low heat operation. It is the teaching of the art that such a sequence is to be followed to provide relatively efficient drying followed by gradually cooling down of the dryer so that a relatively low temperature level is present at the end of the cycle. However, the most efficient drying is shown in U.S. Pat. No. 3,116,983 where a low heat 120 volt input is utilized over the entire cycle.
Many machine washable clothes currently available are chemically treated to exhibit permanent press charcteristics. The permanent press process does not prevent the clothes from wrinkling, but rather acts to smooth out wrinkles in the clothes when the clothes are elevated to a certain temperature. Thus, when permanent press clothes are dried in a conventional dryer having a cycle of low heat input only, the clothes generally are not elevated to a sufficiently high temperature to activate the de-wrinkling properties of the permanent press treatment. Since with a low heat input constituting the entire cycle of operation there is generally not a sufficient temperature rise to activate the permanent press treatment, the permanent press clothes emerge from such a conventional low heat drying cycle with wrinkles.
SUMMARY OF THE INVENTION
An automatic clothes drying appliance is provided with a dual energy input cycle and apparatus which operates a drying cycle at a low energy input level for a majority of the cycle and a high energy input level for a small portion of the cycle at the end of the total drying period. Dryers utilizing an electric heating element are provided with a plurality of cam actuated switches driven by a timing motor. The cams operate switches to control associated circuitry so that the heating element is energized at 120 volts for the majority of the drying cycle and at 240 volts for a period at the end of the drying portion of the cycle.
Dryers utilizing a gas burner are provided with at least two solenoid actuated valves connected to a gas supply which are also controlled by cam operated switches moved by a timing motor. The switches are activated to open at least one gas valve during the entire drying portion of the dryer cycle, and to change the second gas valve from a low heat to a high heat opening during a portion of the cycle at the end of the drying portion.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly broken away, of an automatic clothes drying appliance.
FIG. 2 is a schematic diagram of a dual energy input circuit for an electric heating element.
FIG. 3 is a schedule showing the operation of various switches in FIG. 2 during a drying cycle.
FIG. 4 is a schematic diagram of a dual energy input means for a gas burner.
FIG. 5 is a schedule showing operation of various switches in FIG. 4 during a drying cycle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An automatic clothes drying appliance is shown generally at 10 in FIG. 1. The dryer 10 has a cabinet 11 having a hinged door 12 opening on a front thereof. The dryer 10 has a control panel 13 having a control dial 15 which is user-operable to selectively set a control device 14 for various drying cycles of operation, as for example, a timed drying cycle.
A flange 20 in the front of the cabinet 11 defines a receptacle opening 21 through which clothes may be deposited in a rotatable drum 22. The drum has radially inwardly extending vanes 25 mounted on an interior surface thereof, and is rotated by a suitable drive means 23.
A rear wall 29 of the dryer, against which drum 22 rides in air sealing relationship, has an air inlet 26 and an air outlet 28 therein. A perforated wall 26a extends vertically within inlet 26 and is mounted to an inlet air duct 27a. Within the inlet duct 27a is a heating element shown generally at 27. The perforations in the wall 26a allow the heat from the heating element 27 to enter the drum 22 through the perforations. Outlet 28 is formed by perforations in rear wall 29. Air is circulated from the surroundings through duct 27a, heated by element 27 and then through inlet 26, through the drum 22 to the outlet 28 by a fan 23a driven by the drive means 23. It will be understood that the heating element 27 in duct 27a may be electrical element or a gas burner. Where the heating element comprises a gas burner, the burner may be located below the drum 22 and the duct 27a extended to form an air communication channel between the burner and the inlet 26.
The dryer 10 may also be provided with a removable lint trap 24. It will be understood that positioning of the various elements in the dryer 10 as shown in FIG. 1 is for illustrative purposes only, and the elements need not occupy the position shown.
A circuit diagram for operation of the dryer of FIG. 1 at two energy input levels is shown in FIG. 2. The circuit has two input terminals 31 and 32 and a grounded input terminal 33. A low level input voltage, such as 120 volts, may be applied between the input terminals 32 and 33 or 31 and 33, and a high voltage input level, such as 240 volts, may be applied between the input terminals 31 and 32.
A drive motor 34 is connected to a single pole-double throw centrifugal switch 35 which is in a position making contact with a terminal 35a when drive motor 34 is at rest. Thus, a start winding 34a and a run winding 34b are connectable in parallel to a source of potential at pole 35c. Closure of a biased normally open push-to-start switch 36 by a user causes connection of the drive motor 34 across the 120 volt supply from terminal 31, closed switches 38 and 37 (hereinafter explained), through switch 36, pole 35c, contact 35a and motor 34 windings 34a and 34b to terminal 33. Rotation of the motor 34 as thus connected causes the pole of centrifugal switch 35 to move from contact 35a to 35b, thus maintaining energization of motor run winding 34b through switches 37 and 38 even though switch 36 is released. A door switch 37 is open whenever the door 12 is open, thus insuring that operation of the dryer 10 will not be initiated with the door 12 open.
Rotation of timer dial 15 or operation of a timer motor 42 operates a number of rotating cams (not shown) within control 14 which push against spring contacts to make and break cam operated switches 38, 39, 40 and 41 in the manner well known to those versed in the art. Thus, the switches can be set by a user of a dryer to selected positions by dial 15 and made or broken at selected intervals during the dryer cycle by timer motor 42.
A suggested schedule of operation of the cam operated switches is shown in FIG. 3, indicating the relative on-off positions of switches 28, 29, 40 and 41 during a cycle of operation. The numbers noted thereon indicate a suggested maximum duration in minutes that each switch remain closed during the cycle. Rotation of control dial 15 determines the actual duration selected by positioning the cams with respect to switches 38, 39, 40, 41 in a conventional manner. The numbers are suggested durations only, and variations can be effected without departing from the concept of this invention. The sequence of opening and closing is, however, necessary for proper operation in order to obtain the advantages contemplated by this invention.
During a low level energy input portion of the drying cycle, the control dial 15 is set to close the switches 38, 39 and 41. Once these switches are set, timer motor 42 through switch 38 is connected to electrical potential at terminals 31, 33 and begins operation to sequence the switches as shown in FIG. 3. Closure of the push-to-start switch 36 begins operation of the drive motor 34 as previously explained. Movement of the motor 34 closes aother centrifugal switch 45 so that heater element 27 is energized at 120 volts from terminal 33 through closed switch 41, a pair of normally closed thermostats 43 and 44, through the heater and the closed switch 45 to terminal 32. Thermostat 43 is provided to control the maximum operating temperature and thermostat 44 is a safety thermostat to insure that heater operation will be discontinued if the temperature moves above a pre-selected over heat level.
After operation at 120 volts for a selected amount of time, the timer motor 42 moves cams to open the switch 41 and thereafter to close the switch 40. The cams are positioned to open the switch 41 slightly before closing the switch 40, and are also positioned to "fast make" the contact of switch 40 to energize heater 46 with 240 volts to reduce contact arcing of the switch 40. With this arrangement of switches, the heater 46 is energized at a high level energy input of 240 volts from terminal 31, through closed switches 39 and 40 and thermostats 43, 44 through the heater and centrifugal switch 45 to terminal 32.
After a relatively short period of operation in the 240 volt mode redundant switch 39 provides a "fast break" of the 240 volt circuit to heater 27. The rotation of the cams in control 14 "fast breaks" the switch 39 to reduce contact arcing and then opens switch 40. The drying portion of the cycle ends but the drum 22 continues to rotate with no heat provided, allowing the clothes and drum to cool. The cycle ends when the timer motor 42 rotates to cause the opening of switch 38, and the subsequent cessation of rotation of the drive motor 34 again opens the centrifugal switches 45 and 35.
A schematic circuit diagram showing a dual energy input apparatus for a gas dryer is shown in FIG. 4. Operation of the circuit shown in FIG. 4 is in many respects similar to operation of the circuit of FIG. 2. The apparatus of FIG. 4 has input terminals 50 and 51, and a grounded terminal 52. A suitable voltage level, such as 120 volts, may be placed across the terminals 50 and 51.
A motor 53 has a run winding 53b and a start winding 53a which are connected in parallel during starting of the motor 53 by way of a centrifugally operated switch 56, having stationary contacts 56a and 56b. A push-to-start switch 57 is manually operated to move from a stationary contact 57b to a second stationary contact 57a.
Manual pre-setting of dial 15 of a timer motor 54 and cams (not shown) in control 14 closes cam operated switches 58 and 60 in a conventional manner, so that operation of the push-to--start switch 57 to contact 57a actuates the motor 53. Upon sufficient rotation of the motor 53 the contact 56 transfers from the contact 56a to remove the starting winding from the circuit and engages stationary contact 56b. Thus, even though push-to-start switch 57 returns to contact 57b when released, an operating path for the run winding 53b is provided from terminal 50 through switch 58, contacts 56a and 56, run winding 53b and a door operated switch 55 to terminal 51.
The door safety switch 55 is open whenever the door 12 is open, to prevent operation of the dryer when the door 12 is open. Another centrifugal switch 65 closes when the motor 34 has attained a sufficient angular velocity.
Operating thermostat 61 and safety thermostat 62 are provided to control the amount of heat for drying similar to thermostats 43 and 44 previously discussed in FIG. 2.
Operation of the cam operated switches 58, 60 and 64 by rotation of timer dial 15 or timer motor 54 is shown in the schedule of FIG. 5 with suggested maximum durations similarly indicated as in FIG. 3. The switches control the flow of fuel to a gas burner apparatus 59 including a burner 70. The burner 70 receives fuel from an input pipe 66. Fuel flow in the pipe 66 is controlled by a series of valves 67, 68 and 69. Electrical potential is provided to the gas burner apparatus after motor 53 operation has begun by way of closed switch 60, and normally closed thermostats 61, 62 from terminal 50 and closed door switch 55 and centrifugual switch 65 from terminal 51.
The gas burner apparatus 59 includes a pair of windings 71 and 72 for controlling the opening and closing of valve 69. The energizing potentials supplied across windings 71 and 72 from switch 65 and the contact 62a of the thermostat 62, and by way of normally closed contacts 75 and 76, energize the windings to open the valve 69. At the same time, these energizing potentials are being supplied to an igniter 74 which may be constructed of a silicon carbide composition and which is energizable to glow and provide an ignition temperature for the gas. The gas from the supply is, however, prevented from reaching the vicinity of the igniter 74 by a closed valve 68. The opening and closing of the valve 68 is controlled by the energization and de-energization of a winding 73 which is shunted by the closed contacts 75 and 76. The contact 75 is temperature sensitive and opens in response to the attainment of an ignition temperature by the igniter 74 to remove the shunt across the windings 73 and to permit energization thereof to open the valve 68 and to permit gas flow to the burner to produce a flame 70a.
A valve 67 is also provided in series in the gas circuit. This valve 67 is a two-level valve which is normally closed in a flow restricting condition to provide a first quantity of gas to the burner, and is operable under the control of a winding 77 to a fully open condition to provide a greater quantity of gas flow to the burner. Winding 77 is connected to a source of potential through switches 64 and 60 to terminal 50, and through centrifugal switch 65 and switch 55 to terminal 51. The winding 77 is de-energized in the initial portion of the drying cycle because switch 64 is open as shown in the schedule of FIG. 5.
During the initial portion of the drying cycle the windings 71, 72 and 73 are energized to open the valves 68 and 69 and the winding 77 is not energized so that the valve 67 provides a restricted quantity of fuel to the burner to provide a low level of heat output, for example 10,000 BTU/Hr. Near the completion of the drying cycle as shown in the schedule of FIG. 5, switch 64 is closed under control of the timer motor 54 to operate the gas burner at a high level of heat output through energization of winding 77. This high level of heat output may be, for example, 25,000 BTU/Hr.
The timer motor continues operation to complete the cycle and open all switches, thereby ceasing drying and rotation of the drum 22.
Although changes and modifications may be apparent to those versed in the art, it is applicant's intention to embody within the patent warranted hereon all such changes and modifications which are reasonably and properly within the scope of applicants' contribution to the art. | A method and apparatus for drying clothes wherein a clothes dryer is operated at a low level of energy input for a major portion of a drying cycle, followed by a high energy input for a short period near the end of the drying cycle. A single heater provides both levels of energy input, and has associated control means to operate the heater at the different input levels. For example, an electric heater element is controlled by cam actuated switches to operate at two levels of voltage input or a gas burner is provided with two solenoid actuated valves which are also controlled by cam actuated switches to operate the burner at two different levels of fuel input. | 3 |
This application is a division of application Ser. No. 08/715,124, filed Sept. 17, 1996, which is a continuation-in-part of application Ser. No. 574,270, filed Dec. 18, 1995, now U.S. Pat. No. 5,609,711, which is a continuation-in-part of application Ser. No. 444,936, filed May 19, 1995 and now abandoned, which was a continuation-in-part of application Ser. No. 263,360, filed Jun. 21, 1994 and now abandoned.
BACKGROUND OF THE INVENTION
Starch is the commonly used adhesive for making corrugated paperboard. The common means of application of the starch adhesive is to apply the starch at about 28% solids with a glue roll, by rotating the roll in a pond of adhesive to convey the adhesive to the flute tips of the corrugating medium, to adhere the liner face sheet or sheets to the medium. A so called "carrier" portion of about 20% of the starch is gelatinized (cooked) to hold the raw starch in suspension for handling and application. An equivalent alternative approach is the "no carrier" method in which all the starch is partially gelatinized to accomplish essentially the same purposes as the carrier system.
In the parent application to the present one, U.S. patent application Ser. No. 08/574,270, I describe an adhesive system for corrugated board involving providing an essentially ungelatinized starch suspension which is significantly gelatinized in the application device before application by extrusion onto the medium.
SUMMARY OF THE INVENTION
The present invention incorporates a process of melting and cooling a starch suspension in water under pressure to reduce the viscosity of gelatinized starch in order to provide a starch adhesive of relatively high solids, high initial tack, and moderate viscosity. This process is possible because of the hysteresis inherent in the temperature/viscosity curve for starch as it is heated, melted, and cooled under pressure, as described in my above mentioned application for U.S. patent Ser. No. 08/574,270, which is herein incorporated by reference.
Because of the viscosity reduction and tack increase, the starch adhesive is made more useful when used for making corrugated paperboard, and the process provides an adhesive also applicable to other applications, such as replacement of hot melt adhesives or cold glues (PVA, etc.) in industrial applications such as carton sealing and paper laminating. The reduced viscosity of the starch adhesive makes it easier to apply by known application technologies including glue roll, extrusion or flooded nip.
It is an object of the invention to provide a low cost adhesive to join water wettable, absorbent materials such as paper, wood and the like.
It is an another object to provide an adhesive with moderate viscosity and with good initial tack, as applied.
It is a further object to provide a starch adhesive which is fully gelatinized before application, but which has decreased viscosity and increased tack, at a given application temperature, compared to those characteristics when first gelatinized and heated to that temperature.
It is an additional object to provide a starch adhesive which has been prepared by melting and cooling a starch suspension, so that the resulting composition may be used as an adhesive as so prepared, or may be further modified by mixing with other materials, including ungelatinized starch.
It is yet an object to provide a starch adhesive which can be utilized to improve the effectiveness of the manufacture of corrugated paperboard and similar manufacturing processes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a generalized temperature/viscosity curve for heating and cooling a starch suspension.
FIG. 2 is a block diagram showing the basic steps involved in the process of the present invention.
FIG. 3 is a schematic block diagram of alternative set of equipment for practicing the present invention, utilizing a mechanical screw extruder.
FIG. 4 shows a schematic block diagram of a second alternative set of equipment for the process, utilizing a continuous reactor.
FIG. 5 shows a diagram of a third alternative set of equipment using pumped recirculation.
FIG. 6 shows a diagram of a fourth alternative equipment set using a high solids starch pump.
FIG. 7 shows a diagram of an alternative equipment set using, a batch reactor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a graphical representation of a typical viscosity/temperature relationship for a starch bearing composition undergoing a heating cooling cycle within a pressurized processing device, or system. The estimates of viscosity and other conditions refer to tests on a 50% solids composition of a corn starch. Other starch types and compositions will vary somewhat from those of this example. For example, a 50% solids composition of commercial corn flour will have higher viscosities at all temperatures.
The pressurized container used for the following described tests included a transparent glass tube allowing observation and permitting visual judgments of the properties studied.
Referring to FIG. 1, the temperature rise from Point A to Point B represents the initial heating of the ungelatinized suspension of starch in water. There is only a very slight decrease in viscosity with temperature, as is typical of aqueous suspensions.
Increasing the temperature slightly from Point B to Point C shows the dramatic increase in viscosity as the starch suspension is heated to the gelatinization temperature and is gelatinized to a stiff gel. At this point it has a viscosity somewhat similar to that of a commercial petroleum jelly at room temperature. A bead of gel extruded at Point C will readily hold its shape and will dry in that form unless forcibly reshaped. If the gel at Point C is cooled to Point C' at ambient temperature the basic nature of the gel is unchanged.
Increasing the temperature from Point C to Point D shows the gradual decrease in viscosity with temperature of the starch gel. At Point D a distinct softening occurs.
The relatively small increase in temperature from Point D to Points E and F causes the composition to become very fluid. At that point it has a viscosity approximating that of a light weight SAE 10 motor oil.
As the composition is cooled from Point F to Point G the viscosity change (increase) is much lower than the incremental change (decrease) during the heating cycle. This hysteresis enables the extrusion or other application of adhesive at Point G with the desired reduced viscosity, increased tack, and absence of puffing which would otherwise have been caused by the flashing of water in the composition upon extrusion at higher temperatures. The reduced rate of incremental viscosity increase from Point F prevails all the way to ambient temperature at Point G'.
Preferably, the composition is cooled to a temperature of 150° C. or below before use. Most preferably, it will be cooled to a temperature near or below 100° C. For most uses the preferred application temperature will be about 90° C. to 100° C. where the viscosity will be near or in the minimum range.
The adhesives of the invention can advantageously be used for the manufacture of corrugated paperboard. They can be applied by a typical glue spreader, in which an applicator roll revolves in a pond of adhesive and prints the adhesive composition on the tips of the fluted corrugating medium prior to combining with a liner sheet. They can also be applied from an extruder or by other means as is shown in my application Ser. No. 574,270. A particular advantage of the present adhesive so used is the ability to apply it at higher solids content because of the reduced viscosity. Stated differently, a higher solids adhesive has a lower moisture content which enables drying time and, potentially, sheet warpage to be reduced.
FIG. 2 is a block diagram presenting the basic steps involved in the process of the present invention. A starch suspension in water is fed into a pressurized system in which the starch is heated, melted, then cooled. The physically altered composition is then removed from the pressure zone and comprises an adhesive ready for use, or for further compounding. The process may be practiced by different configurations of known equipment, including those described below. Also detailed steps, not shown, can be utilized to conserve energy consumption in the process, or otherwise improve the effectiveness of the process. Gelatinized starch can be processed as shown, but it will normally be preferred that the feed be an essentially ungelatinized starch composition. Essentially any formulation of starch, from any starch source, can be used in the process. Normal corn starch is preferred in many instances because of its low cost and good availability, but other starches can be utilized for their economy or to alter the characteristics of the product adhesive. The process is highly amenable to the use of known additives of many types such as inert additives for economy, plasticizers, tackifiers, additives for water resistance or water solubility, and the like. The process is usable over a very broad range of starch solids, covering at least the range of 20% to 80% starch solids. Further, it is quite easy to adjust the solids level up or down within the process. In order to contain water vapor pressures at the temperatures described in FIG. 1, system pressures of 250 to 300 psi (17 to 20 bars) are required. In the process, the final cooling step is operated to end at the desired temperature for use of the adhesive product as is, the viscosity and tack at that temperature having been adjusted by the process parameters as described in FIG. 1. Cooling below that temperature and reheating will involve some redundant hysteresis in the viscosity/temperature relationship. The product can also be further compounded in any way desired, such as mixing with another adhesive, or mixing with gelatinized or ungelatinized starch. When the added composition is an ungelatinized starch, the melted and cooled starch would be cooled to a range of 40 to 60 degrees C. as appropriate to get below the gelatinization temperature of a typical modified corn starch, and to a range of 55 to 70 degrees C. to get below the gelatinization temperature of an unmodified corn starch which typically has a gelatinization temperature of about 74 degrees C.
FIG. 3 illustrates the use of a mechanical screw extruder to operate the process. This is especially applicable in the higher ranges of solids, say above 55% solids. Both single screw and twin screw extruders are widely used for starch processing. Supplemental heating and subsequent cooling can be added internal to the extruder or external as desired. A discharging device is required, which can be, for instance, a back pressure control valve, or a rotary discharger device of known design.
FIG. 4 illustrates the use of pumped starch feed to a continuous heating/melting reactor. The basic principles of the reactor are known but it would be fitted with an internal rotor which would cause significant recirculation of the molten starch, and ensure good heat transfer between the heated reactor wall and the mixture of recirculating molten starch and the makeup starch feed stream. A product stream would be taken off in the zone of fully melted starch and cooled as desired in heat exchanger equipment. This equipment configuration would be used at lower solids levels, below about 50% solids, to enable the pumping of the starch suspension.
FIG. 5 illustrates the use of known pumping and heat exchanger technology to operate in a manner very similar to the recirculating reactor of FIG. 4. This alternative also is applicable to the solids range below 50% solids.
FIG. 6 shows the general configuration of the recirculation option of FIG. 5 except using a more specialized pump to enable feeding starch at solids levels above 50%. This is a very demanding pumping application requiring a special pump such as a plunger type pump or a twin screw pump for these higher starch solids levels.
FIG. 7 shows the use of a batch operated reactor, in which a capping valve is opened for charging the starch to the reactor at any solids level desired, from the lowest to the highest. After charging the reactor with starch, the capping valve is closed for heating, melting and cooling the starch under pressure in the reactor. The completed product is transferred to a storage tank.
It will be evident to those skilled in the art that many variations can be made in the process which are not herein described in detail. These variations should be considered to be within the scope of the invention if within the encompass of the appended claims. | A method of preparing a starch adhesive ready for use in which a starch bearing, compound is fed to a pressurized system in which the starch is heated, melted, cooled and removed from the pressurized system to comprise an adhesive ready for use. The temperature of the product is maintained above 40° C. to prevent irreversible viscosity increase due to system hysteresis. The adhesive product is especially useful for use in manufacturing corrugated paperboard. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage application of PCT/SE2007/050078, filed Feb. 8, 2007, which claims priority from Swedish application SE 0600305-7, filed Feb. 10, 2006.
FIELD OF THE INVENTION
The present invention relates to magnetic field sensors, memory elements, and three-terminal logic devices for recording head, external field sensing, MRAM and logic applications. In particular the invention provides improved magnetic junction devices based on doped MgO layers.
BACKGROUND OF THE INVENTION
A device comprised of two ferromagnetic layers separated by an insulating tunnel barrier is known as a magnetic tunnel junction (MTJ). The cross-section of a conventional MTJ is illustrated in FIG. 1 . It consists of bottom terminal 18 placed on a substrate or an underlayer, followed by the first magnetic layer 14 , the oxide tunnel barrier 10 , the second magnetic layer 12 , and the top terminal 16 . The resistance of such MTJ is a function of the relative orientation of the magnetizations of the two magnetic layers, being lowest for parallel (P) alignment and highest for anti-parallel (AP) alignment. One of the magnetic layers is made magnetically hard and the other magnetic layer is made magnetically soft such that the two layers switch in different magnetic fields. This can be achieved either by choosing magnetic materials of different magnetic anisotropy or by exchange biasing one of the layers using an antiferromagnetic layer. The P and AP states are realized by applying an external magnetic field sufficient to switch the soft layer but not the hard layer. The associated change in resistance can be used to sense magnetic field in such device as a read head of a hard drive in magnetic recording as described in [1]. Such high-MR MTJ's can also be used as storage elements in MRAM as described in [6]. Here the different resistance values for P and AP states of the junction correspond to stored values of the magnetic bit, “0” and “1”.
It is essential for sensor applications that the signal to noise ratio (SNR) of the device is large. The signal for a magnetic junction sensor is the voltage given by the change in resistance caused by an applied magnetic field (ΔR−deltaR) times the biasing current flowing through the junction (I B ), V S =I B ΔR. The predominant noise mechanism of the magnetic junction is its thermal noise, which is proportional to the square root of the device resistance, R 0.5 . In an MTJ the device resistance is dominated by the resistance of the tunnel barrier, such as Al—O, with the leads and the ferromagnetic layers making a vanishingly small contribution. It is therefore highly desirable to decrease the resistance of the barrier (R) without reducing ΔR. R increases as the junction is made smaller in inverse proportion to the junction area (A), the product RA remaining essentially constant. Therefore, for smaller junctions of the future generations of field sensors the demand for reducing the resistance of the barrier is even higher. The desired values for the resistance-area product are RA<1000 Ohm-um 2 , preferably RA<10 Ohm-um 2 as described in [2]. Similar noise and scaling considerations apply to MTJ's used in MRAM [6]. Additionally, low resistance barriers are required for MRAM cells utilizing the effect of current induced magnetization switching, described in [3,4] and experimentally observed in [5]. Relatively high currents (typically a few mA) flowing through an MTJ are needed for producing switching of the soft magnetic layer. In order not to exceed the breakdown voltage of the MTJ (approximately 1 V) the resistance of the junction should preferably be smaller than 1 kOhm. This corresponds to preferably RA<10 Ohm-um 2 for a junction of ˜0.01 um 2 in area.
The resistance of a tunnel barrier is an exponential function of the barrier thickness, with thinner barriers having lower resistance. For very thin barriers of thickness less then 1 nm, however, the useful signal (ΔR) decreases due to microscopic pinholes and other defects in the barrier as described in [2]. It is therefore desirable for sensor and MRAM applications to have an independent means of reducing the resistance of the barrier while preserving the barrier thickness, necessary for achieving high MR.
Another desirable characteristic of a magnetic junction is current rectification. This property is conventionally realized in semiconductor diodes and is manifest in different currents through the device for a given bias voltage of positive and negative polarity. The ratio of these two current values is known as the rectification ratio (RR). Incorporating a diode in series with an MTJ in an MRAM cell can provide a significantly improved memory density as described in [6]. The diode blocks current for one bias polarity through MTJ's placed at cross-points of a 2D array of word and bit lines and allows current for the other bias polarity, thus providing a cell select mechanism built into the MTJ stack. However, fabricating efficient semiconductor diodes within metal-oxide MTJ stacks is a highly non-trivial task. It is highly desirable that the diode function is implemented within the same metal-oxide material system. Double tunnel junctions of the general structure magnet1/oxide/metal/oxide/magnet2 with atomically thin metal center electrodes and asymmetric oxide tunnel barriers can exhibit current rectification as described in [7]. Such diode structure is a variation of a conventional semiconductor Resonant Tunneling Diode described in detail in e.g. [8]. The spin sensitivity of the outer electrodes (magnet1 and magnet2) combined with transport through discrete energy states in the center electrode can provide high-MR and diode functionality—an ideal combination for use in MRAM applications. The thickness of the center metal layer must be comparable to its Fermi wavelength, which is smaller than 1 nm in most metals. For such thin metal layers dimensional quantization in the direction of current (perpendicular to the layers) results in transport through discrete electron states in the layer. Roughness of even one monolayer can significantly affect the performance of the device. The need for atomically thin and atomically smooth metal layers imposes practical limitations on the use of such a double barrier device where the center electrode is a metal.
The electronic energy states of the center electrode in the double-junction described above can be affected electrically by an additional electrode placed in physical or electrical contact to the center electrode—a gate. Such a spin-dependent three-terminal device is a variation of a conventional Resonant Tunneling Transistor described in detail in e.g. [9]. The combination of MR and gate control can provides the basis for novel logic applications, in particular in reprogrammable logic [10].
Use of MgO yields MR (ΔR/R) of 100%-1000% in magnet1/MgO/magnet2 type junctions as described in [11]. The commonly used materials for the magnet layers are Fe, Co, Fe—Co, Fe—Ni, Fe—Co—B alloys. Magnetic junctions based on MgO are preferred in applications based on MR compared to junctions based on, for example, Al and Ti oxides where the typical MR value is ˜30%. Therefore, it is highly desirable for sensor, memory, and logic applications described above to improve the MgO barrier in such a way as to lower its resistance for a given thickness.
Thus, it is in the art demonstrated the envisaged potentials of devices utilizing tunneling effects, comprising dual magnetic layers. However, the performance of such devices is presently often impaired by defects relating to the problems of providing thin enough layers separating the magnetic layers.
SUMMARY OF THE INVENTION
Obviously an improved method and device, that makes it possible to fully take advantage of the possibilities of magnetic tunneling devices, are needed.
The object of the present invention is to provide a device and method of producing such that overcome the drawbacks of the prior art techniques. This is achieved by the device and the method of the present invention.
The present invention provides a low-resistance high-MR junction of two magnetic layers separated by a doped MgO layer. The magnets can be such known ferromagnetic metals as Fe, Co, Ni, Fe—Co, Ni—Fe, Fe—Co—B, other ferromagnetic or ferrimagnetic metal alloys or semiconductors. The MgO layer is doped with such elements as Al or Li to lower the resistance of the material. Such Mg x M y O layers (M=Al, Li, . . . ) are formed by depositing a film of Mg—Al or Mg—Li with a subsequent exposure to an oxygen atmosphere. Alternatively, the Mg x M y O layer can be formed by reactively sputtering the Mg—Al or Mg—Li alloy in a mixture of Ar—O 2 . The MTJ is formed by sequential deposition of magnetic layer 1 , Mg x M y O layer, and magnetic layer 2 .
The present invention provides a magnetic double junction device having an asymmetric current-voltage characteristic (diode function). Such a device is formed by two magnetic layers such as Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other ferromagnetic alloys or semiconductors. The two magnetic layers are separated by generally a tri-layer of MgO/Mg x M y O/MgO, where the thicknesses of the individual layers are adjusted to optimize the MR and the diode characteristic of the device. MgO/Mg x M y O/MgO tri-layer can be formed by a sequential sputtering of the Mg, Mg x M y (M=Al, Li, . . . ), and Mg layers in a mixture of Ar—O 2 . The double-MTJ is formed by sequential deposition of magnetic layer 1 , MgO layer 1 , Mg x M y O layer, MgO layer 2 , and magnetic layer 2 .
The present invention provides a three terminal magnetic junction. Such a device is formed by two magnetic layers such as Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other magnetic alloys or semiconductors. The two magnetic layers are separated by generally a tri-layer of Mg/Mg x M y O/MgO, where the thicknesses of the individual layers are adjusted to optimize the MR and the trans-resistance of the device. An additional gate electrode is placed in physical or electrostatic contacts with the center Mg x M y O layer to affect its electronic configuration. In addition to MR the conduction through the device is sensitive to the potential on the gate electrode, making it a spin dependent trans-resistor. MgO/Mg x M y O/MgO tri-layer can be formed by sequential sputtering the Mg, Mg x M y (M=Al, Li, . . . ), and Mg layers in a mixture of Ar—O 2 . The double-MTJ is formed by sequential deposition of magnetic layer 1 , MgO layer 1 , Mg x M y O layer, MgO layer 2 , and magnetic layer 2 . One implementation is to suitably pattern magnetic layer 2 to allow a contact to the top MgO layer of a metallic gate electrode.
It will be understood by those skilled in the art that the said method of formation of the doped MgO layer by sputtering off an Mg target in Ar—O 2 mixture is one example. Other methods include, but are not limited to, sputtering of a composite Mg x M y O oxide target in Ar, sputtering off an MgO target in Ar—N 2 mixture, or sputtering off an Mg target in Ar—O 2 —N 2 mixture. In these cases M=Li, Al, N, . . . act as dopant atoms in MgO, with metal atoms preferentially substituting Mg and N atoms preferentially substituting O.
Embodiments of the invention are defined in the dependent claims. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings and claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 illustrates a cross-section of a conventional magnetic junction having an MgO oxide layer separating two magnetic layers.
FIG. 2 illustrates a cross-section of a magnetic junction having a doped MgO layer separating two magnetic layers, according to the present invention.
FIG. 3 illustrates a cross-section of a magnetic junction having a doped MgO layer and two MgO oxide layers separating two magnetic layers, according to the present invention.
FIG. 4 a,b illustrate a cross-section of a vertical magnetic junction having a doped MgO layer and two MgO oxide layers separating two magnetic layers and a third terminal in electrical (a) or physical (b) contact with the center Mg x M y O electrode, according to the present invention.
FIG. 5 illustrates a cross-section of a lateral magnetic junction having a doped MgO layer and a MgO oxide layer separating two magnetic layers and a third terminal in the vicinity of the center Mg x M y O electrode, according to the present invention.
DETAILED DESCRIPTION
As described in the background multilayered magnetic devices utilizing tunneling effects, hereinafter refereed to as magnetic tunneling devices, are difficult to manufacture, or alternatively do not give the desired effects. Of special interest is the tunnel barrier 10 , typically of MgO, in between the magnetic layers 12 , 14 as illustrated in FIG. 1 , and the center layer in magnetic double junctions. According to the present invention a tunnel barrier and/or a center layer is provided comprising a doped magnesium oxide (MgO). The dopand is preferably Al or Li. Also doping with B, Na, Si, P, S, K, Sc, Ti, Cu, or Rb is possible. The result of the doping, in the case of a MTJ, is that a material with reduced resistance compared to MgO is provided. Thereby the spacer layer can be made thicker without decreasing the performance of the device, or alternatively the performance may be increased maintaining the same thickness.
Tardio et al. [12] describe an experiment of doping chemically or by ion implantation MgO crystals with Li. They observe very large increases of 7 to 14 orders of magnitude in the electrical conductivity of the doped material compared to the nominally insulating pure MgO. Mg is a valence 2 metal, so doping with Li of valence 1 leads to formation of holes and a p-type semiconducting behavior. Other dopands in MgO discussed in the literature include Al, Cu, Co, Ni [13, 14, 15, 16]. As in the case of Li-doping, larger concentrations of other dopands are expected to substantially increase the conductivity of nominally insulating MgO. Thus doping provides a means for increasing the conductivity of MgO, which is desirable for the sensor, memory, and logic devices discussed.
In the case of devices utilizing a magnetic double junction, for example magnetic tunneling diodes and transistors, the doped MgO as a central layer results in a conductive center layer with significantly longer Fermi wavelength (lower carrier density) compared to the previously reported metal layer. The center layer according to the invention can be made thicker and is process compatible with the metal oxide stack.
One embodiment of the present invention is a magnetic tunnel junction, MTJ, as illustrated in FIG. 2 , fabricated on a substrate or an underlayer generally as a part of an electronic circuit. Terminals 26 and 28 are connected to magnetic layers 22 and 24 . The magnetic layers are preferably Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other magnetic materials. Separating the magnetic layers is a layer of doped MgO, denoted Mg x M y O 20, produced for example by post-deposition oxidation or reactive sputtering in Ar—O 2 atmosphere of Mg, which is alloyed with such elements as Li or Al (M). The concentration of Mg is preferably x>0.9. The concentration of the dopant is y<<1, preferably y<0.1. The magnetic junction is formed by sequential deposition of layers 24 , 20 , 22 . The object of the doping of the Mg x M y O layer 20 is to provide a layer that has a smaller resistance than a corresponding layer of undoped MgO for layer thickness >1 nm. The junction comprising a doped Mg x M y O layer 20 should preferably have a resistance of <10% of that of a junction with an undoped MgO layer. The layer of doped Mg x M y O can be made in the order of 1 to 10 nm and still maintaining the performance of the MTJ, compared to around 1 nm in a MTJ using undoped MgO. As apparent to the skilled in the art this is a great advantage from a production point of view.
A second embodiment of the present invention is a magnetic double junction as illustrated in FIG. 3 , fabricated on a substrate or an underlayer generally as a part of an electronic circuit. Terminals 36 and 38 are connected to magnetic layers 32 and 34 . The magnetic layers are preferably Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other magnetic materials. The magnetic layers are insulated with MgO layers 31 and 33 from a layer of doped Mg x M y O 30. Layers 30 , 31 , 33 are produced by post-deposition oxidation or reactive sputtering in Ar—O 2 atmosphere of doped and pure Mg in the case of layer 30 and layers 31 and 33 , respectively. The concentration of Mg in layer 30 is preferably x>0.9. The concentration of the metal dopant is y<<1, preferably y<0.1. The magnetic double junction is formed by sequential deposition of layers 34 , 33 , 30 , 31 , 32 . In addition to MR the device has diode functionality. The thicknesses of the two MgO barriers are individually varied from <1 nm to approximately 3 nm to optimize the MR (preferably >20%) and the diode effect (preferably RR>10). Compared to the center metal layer in previous magnetic double junction devices the center layer in the device according to this embodiment of the invention can be made significantly thicker, 1-100 nm, and the device still maintaining its functionality as regards to MR and RR.
A third embodiment of the present invention is a three terminal device as illustrated in FIG. 4 , fabricated on a substrate or an underlayer generally as a part of an electronic circuit. Terminals 46 and 48 are connected to magnetic layers 42 and 44 . The magnetic layers are preferably Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other magnetic materials. The magnetic layers are insulated with MgO layers 41 and 43 from a layer of doped Mg x M y O 40. Layers 40 , 41 , 43 are produced by post-deposition oxidation or reactive sputtering in Ar—O 2 atmosphere of doped and pure Mg in the case of layer 40 and layers 41 and 43 , respectively. The concentration of Mg in layer 40 is preferably x≧0.9. The concentration of the dopand is y<<1, preferably y<0.1. The magnetic double junction is formed by sequential deposition of layers 44 , 43 , 40 , 41 , 42 . Layers 42 and 46 are patterned in such a way as to allow a third terminal ( 45 ) be placed in contact with MgO layer 41 . Changing the potential on this terminal affects through electrostatic fields the energy levels in layer 40 and thereby the resistance between terminal 1 and terminal 2 . Thus, in addition to MR the device has transistor functionality, with the third terminal ( 45 ) acting as a gate. Alternatively, a physical contact is made between the gate ( 45 ) and the center electrode ( 40 ) as indicated by the dashed area 47 . This can be achieved by a suitable patterning of layers 42 , 46 , 41 .
A variation on the above three terminal vertical device is a lateral device illustrated in FIG. 5 , fabricated on a substrate or an underlayer generally as a part of an electronic circuit. Terminals 50 and 56 are connected to magnetic layers 51 and 53 . The magnetic layers are preferably Fe, Co, Ni, alloys Fe—Co, Ni—Fe, Fe—Co—B, or other magnetic materials. The magnetic layers are insulated with MgO layer 54 from a layer of doped Mg x M y O 58. Layers 58 and 54 are produced by post-deposition oxidation or reactive sputtering in Ar—O 2 atmosphere of doped and pure Mg, respectively. The concentration of Mg in layer 58 is preferably x≧0.9. The concentration of the metal dopand is y<<1, preferably y<0.1. Layers 50 , 56 , 51 , and 53 are patterned in such a way as to allow a third terminal ( 52 ) be placed in contact with MgO layer 54 . Changing the potential on this terminal affects through electrostatic fields the electronic states of layer 58 . Thus, in addition to MR the device has transistor functionality, with the third terminal ( 52 ) acting as a gate.
It will be understood by those skilled in the art that the subdivision of the MgO/Mg x M y O/MgO spacer into three layers in the description of the above embodiments can as well be referred to as an inhomogeneous doping of a single MgO layer. The said method of formation of the doped MgO layer by sputtering off an Mg target in Ar—O 2 mixture is one example. Other methods include, but are not limited to, sputtering of a composite Mg x M y O oxide target in Ar, sputtering off an MgO target in Ar—N 2 mixture, or sputtering off an Mg target in Ar—O 2 —N 2 mixture. In these cases M=Li, Al, N, . . . act as dopand atoms in MgO, with metal atoms preferentially substituting Mg and N atoms preferentially substituting O.
It will be further understood that various changes in form and detail can be made to the above illustrative embodiments without departing from the spirit and scope of the present invention.
REFERENCES
1. Fontan, Jr. et al., U.S. Pat. No. 5,729,410
2. Carey et al., U.S. Pat. No. 6,756,128
3. Slonczewski, U.S. Pat. No. 5,695,864
4. Slonczewski, J. Mag. Mag. Mat. 159, L1 (1996); ibid. 195, L261 (1999)
5. Fuchs et al, Appl. Phys. Lett. 85, 1205 (2004)
6. Gallagher et al., U.S. Pat. No. 5,640,343
7. Chiev et al. Europhys. Lett. 58, 257 (2002)
8. Botez et al., U.S. Pat. No. 6,229,153
9. Frensley et al., U.S. Pat. No. 4,959,696; Yang, U.S. Pat. No. 6,080,996
10. Moodera et al., Nature Materials 2, 707 (2003)
11. Parkin et al. Nature Materials 3, 862 (2004); Yuasa et al. ibid. 3, 868 (2004)
12. Tardio et al. Phys. Rev. B 66, 134202 (2002); Nucl. Instr. and Meth. in Phys. Res. B 218, 164 (2004)
13. Pedrosa et al. J. Appl. Phys. 62, 429 (1987)
14. Kärner et al. Radiation Meas. 33, 625 (2001)
15. Savoini et al. Nucl. Instr. and Meth. in Phys. Res. B 218, 148 (2004)
16. Pinto et al. Eur. Phys. J. B 45, 331 (2005) | The present invention provides a low resistance high magnetoresistance (MR) device comprised of a junction of two magnetic elements separated by a magnesium oxide (MgO) layer doped with such metals as Al and Li. Such device can be used as a sensor of magnetic field in magnetic recording or as a storage element in magnetic random access memory (MRAM). The invention provides a high-MR device possessing a diode function, comprised of a double junction of two outer magnetic elements separated by two MgO insulating layer and a center MgO layer doped with such metals as Al and Li. Such device provides design advantages when used as a storage element in MRAM. The invention with MR wherein a gate electrode is placed in electrical or physical contact to the center layer of the double tunnel junction. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a modular mattress with gradually varying heights toward the center and made of flexible foamed plastic material in superimposed layers having a rigidity, or rather a load-bearing capacity (the ability to support a load by withstanding its weight), which is differentiated in the horizontal component of the mattress and an elastic response, or rather resilience (ability to return mechanical stresses in terms of elastic thrust and rebound), which is differentiated and opposite in the vertical component, i.e., having high elasticity in the base layer and being substantially inelastic in the surface layer.
It is generally acknowledged that in order to avoid damage to the spine, the onset of postural problems and disorders of sleep neurophysiology and therefore ensure the maximum benefit of resting for all the period spent on the mattress, said mattress must allow a physiological and natural position of the body, respecting its anatomy and biological functions with a behaviour which is indeed anatomical and functional.
Accordingly, it is the mattress that must adapt to our body and respect it, not the opposite; however, people have different body types and shapes, whereas it is likely that the same mattress must effectively cope with different anatomical, weight and functional stresses.
In order to achieve these results, mattresses have been proposed which give the body a generic support expressed in terms of an elastic response to the weights that affect the surface, which is unevenly distributed only on a discrete number of points, preventing the spine from maintaining its natural shape, regardless of one's position during sleep, and most of all neglecting and preventing important biological functions which are indispensable for maintaining sleep and the quality of rest, such as:
maintaining the blood flow in the capillaries of surface tissues;
lymphatic and venous drainage of the lower limbs;
pulmonary ventilation;
cardiac activity;
noncompressive compliance on joints and muscles;
maintaining the position assumed in sleep for prolonged times.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a mattress which allows anyone, regardless of his/her anatomy, weight and physical functional condition of course within the limits of extreme pathological conditions), to achieve a physiological posture which is ideal for the quality of sleep and for the well-being of the body.
This aim is achieved by a modular mattress made of flexible foamed plastic material in superimposed layers and with horizontally differentiated load-bearing capacity, vertically opposite elasticity and an architecture with heights which gradually vary from the head and foot edges toward the center of the item.
The mattress, according to the invention, comprises a base layer with containment edges which is composed of two elastic peripheral modules which have a lower rigidity or load-bearing capacity than the central module (where the greatest weight bears), which is also elastic but has a higher rigidity or load-bearing capacity; the modules of said first layer are kept together by joints of the mortise and tenon type; the upper surface layer, contained in said base structure, is made of a special foamed plastic polymer which can be thermoformed under pressure, characterized in that it has a very high formability and indentability arising from a substantial lack of resilience, i.e., of elastic response to mechanical stresses (no appreciable resilience according to UNI6357 standards), preferably of the type known commercially under the trademark Synergel in the name of the Applicant.
In this invention, therefore, the base structure is meant to follow elastically the mechanical deformations and to offer a harmonic and differentiated support to the body as a function of the weight applied; the upper layer of Synergel, by shaping itself on the anatomy of the body, allowing parceling and millimetric distribution of the applied weight over the entire contact surface; furthermore, the inelastic behavior, due to low resilience (i.e. not high enough to be measurable according to the UNI6357 standard), allows an essential cushioning of the compressive elastic return thrusts on the tissues of the body.
The symbiosis between a base layer that appropriately supports the different parts of the body with an elastic action and the upper layer of Synergel (which absorbs, distributes and disperses the weight applied by the body, whose anatomy is also followed by an inelastic and form-fitting action), associated with a particular architecture with heights which gradually vary toward the center, allows the body to assume a position which is adapted to maintain and facilitate said biological functions.
As a whole, the invention offers an innovative sum of features which is meant to increase the quality of rest even in case of tiredness due to sports and/or work, joint and muscle inflammations, impaired cardiac and pulmonary activity, disorders arising from lymphatic and arteriovenous stasis in the lower limbs, gastroesophageal reflux, pregnancy, excessive skinniness, disorders arising from long confinements to bed etcetera.
Furthermore, an object of the present invention is to provide a mattress which is structured so that it can be disassembled in order to allow easy handling during manufacture and transport and when the mattress is to be cleaned or sanitized.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages will become apparent from the following detailed description of the present invention illustrated only by way of non-limitative example in the accompanying drawing, wherein:
FIG. 1 is a perspective view of the mattress according to a first embodiment; and
FIG. 2 is a perspective view of the mattress according to another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the figures, the mattress is generally designated by the reference numeral 1 and comprises an upper layer 2 which rests on a lower layer 3 without applying adhesives or the like.
The upper layer is made of a foamed plastics which is commercially classified as having a substantially null resilience (i.e. so low that it cannot be measured according to UNI 6357). A main feature of such a material is that if a hard body, say a metallic sphere, is sunk by pressure therein, once the body is released, it does not bounce back as it would occur for an elastic/resilient material, but it is only slowly and gradually lifted to the initial level.
Preferably, said material is a polyurethane-based copolymer known commercially as Synergel and marketed by the Applicant. The material "Synergel" is substantially an open cell polyurethanic foam copolymer based composition comprising: 50% of polyester polyol, 12% polyether polyol, 20% toluene diisocyanate (TDI), 1% water, 1% catalysts, and 16% silicone, flameproofing, fungicide and bacteriostatic additives.
The lower layer 3 is composed of a plurality of modular elements, for example three elements 4, 5, 6 made of foamed plastics; the elements 4 and 5 constitute the end elements and the element 6 is the intermediate one.
The end elements 4 and 5 are L-shaped and comprise a base 7 from one side of which there rises a wall 8 whose height is equal to the height of the upper layer.
The end elements 4 and 5 are connected to the intermediate element 6 by transverse joints of the mortise and tenon type. In particular, the transverse element has, along its opposite transverse edges, respective tenons 9 having a circular cross-section which are adapted to engage respective slots or mortises which have a complementary cross-section and are formed along the transverse sides of the bases 7 of the elements 4 and 5.
The tenons 9 and the mortises 10 can of course have any cross-section, for example a dovetail or T-like one, so long as it ensures a sufficiently strong engagement of the elements 4 and 5 with the element 6.
A substantial prerogative of the present invention is the fact that the elements 4, 5 and 6 have differentiated rigidities. In particular, the end elements 4 and 5 have a higher elastic constant than the intermediate element 6 and a lower density and/or load-bearing ability.
For example, the elements 4 and 5 can be made of foamed polyurethane having a density between 20 and 40 kg/m 3 , preferably a density equal to 30 kg/m 3 and a load-bearing capacity of 3.3 KPa+/-15% (40% compression according to UNI 6351), while the intermediate element 6 is made of a foamed polyurethane having a density between 20 and 70 kg/m 3 , preferably a density equal to 40 kg/m 3 and a load-bearing capacity of 5.2 KPa+/-15% (40% compression according to UNI 6351), so long as the density and/or load-bearing capacity of the intermediate element is always higher than that of the end elements.
The above-described mattress, by the combination of the two layers having opposite resilience and of the difference in density and/or load-bearing capacity among the elements 4, 5 and 6, allows to obtain, in the regions subjected to higher loads, elastic reactions which are proportional to the weight that affects them. In particular, the lower layer 3 (4, 5, 6) determines elastic reactions for providing harmonic support at the different parts of the body which reactions, synergistically with the upper layer made of Synergel, reduce the compression of skin tissues that cover protrusions of the bone, of the musculoskeletal system in general and of the capillary vessel system, and accordingly increase the feeling of well-being, allow a physiologically correct posture and ensure a sound sleep, without detrimental interruptions, and consequent physical recovery.
The above-described mattress is susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept. For example, in the embodiment, shown in FIG. 2, the upper layer of Synergel has a slight recess in the central region, so that the mattress has a surface which rises at the opposite ends and causes the user's upper trunk and lower limbs to be physiologically raised with respect to the central part. This arrangement has beneficial effects on anyone, but most of all on individuals suffering from cardiac and respiratory distress and helps to fight swelling and heaviness in the lower limbs.
Preferably, the concave shape of the mattress is achieved by giving a wedge-like shape to the bases of the end elements (also termed modules) or with a degrading cut of the Synergel layer from the ends toward the center thereof.
In the practical embodiment of the invention, the number of elements that compose the lower layer can be any according to requirements.
The disclosures in Italian Patent Application No. BO98A000365 from which this application claims priority are incorporated herein by reference. | A mattress made of foamed plastic material with modulated rigidity, having an upper layer made of a plastic material with a composition based on an open cell polyurethanic foam with silicone, flameproofing, fungicide and bacteriostatic additives, having low elastic memory and being substantially inelastic, which is arranged on a lower layer which is composed of modular elements which are mutually assembled by joints of the mortise and tenon types. | 0 |
PRIORITY CLAIM
This application claims the benefit of U.S. provisional patent application Ser. No. 61/367,380 filed Jul. 24, 2010, and U.S. non-provisional patent application Ser. No. 13/748,371 filed Jan. 23, 2013. The foregoing applications are incorporated by reference in their entirety as if fully set forth herein.
BACKGROUND
Restaurants, institutional kitchens, and other commercial or high-volume food service locations have a need to wash dish and glassware very rapidly. For decades, the most common solution has been a commercial dishwasher, typically incorporating a conveyor belt upon which large racks containing dirty dish and glassware pass through the washing compartment of the commercial dishwasher.
The dish and glassware racks have varied interior configurations, capable of carrying dishes, glasses, and tableware, among other items that are run through the commercial dishwasher for washing. The exterior configuration of the racks is generally the same, however. A dish or glassware rack for use with a commercial dishwasher is typically 19.72″×19.72″ square. Although the height may vary to accommodate small dishes to tall glasses, the lateral profile of racks used with commercial dishwashers is nearly always the same.
Further, racks for use in commercial dishwashers are nearly always stackable, such that dishes and glasses can be vertically stacked for compact storage within the racks. A groove formed in the bottom face of the square rack permits it to be placed on top of another rack, with the top rail of the bottom rack mating with the groove in the bottom face of the top rack. In many racks, the top rail includes locator posts, which are upward-facing protrusions which make the interlock between a bottom rack and a rack stacked above the bottom rack more secure.
One important functional aspect of commercial dish and glassware racks is that they have openings in the bottom of the rack and on all four side walls. This allows water to spray through the bottom or side walls of the rack during washing and reach all surfaces of the dishes or glassware contained within the rack. It is simple to understand that if water could not penetrate the bottom and side surfaces of the rack, efficient cleaning of the dish or glassware would be impossible. The corollary effect, however, is that the water can drip back through the bottom of the rack.
An additional function of the openings in the bottom and sides of the rack is to permit drip-drying of the dish and glassware following its run through the commercial dishwasher. While some conveyor-belt dishwashers have a drying section, many restaurants and other kitchens opt for a commercial dishwasher that is limited to washing and does not include drying capability. Such wash-only dishwashers are less expensive, less complex, and take up less room in the kitchen than one which includes a drying section.
An issue with the use of a wash-only commercial dishwasher, however, is that during drying, the water drips straight through the bottom of the rack and onto the floor, pooling on the floor and possibly creating a safety hazard or other undesirable effect. When multiple dish and/or glassware racks are stacked following their run through the dishwasher, the water from all the racks drips onto the floor. Glasses, particularly, are loaded into a commercial glassware rack upside-down, to facilitate drip-drying. The risk of an employee slipping on the pools of water created when the water drips through the racks onto the floor is high, especially when one considers the tile or other smooth-surface floors often used in the kitchen. Also, on occasion, an employee will carry a rack loaded with dishes or glassware. The holes in the rack will permit the water to drip through the rack onto the employee's clothing, which is undesirable.
Further, when the racks are loaded with dirty dishes or glassware and then transported to the dishwasher, food remnants, unfinished drinks, and other detritus may pass through the bottom of the racks and onto the floor. In addition to the safety hazard described above, germs become an additional concern.
In some restaurants or other kitchens, following washing, the dish or glassware is transported to a storage location. This transport is often facilitated by the use of a dolly. The dolly provides a frame with wheels attached underneath the frame, where the frame is sized to receive a standard commercial dish or glassware rack. A number of racks may be stacked on the dolly, and then the stack of racks may be rolled to where the dishes or glasses are stored. Some dollies have a handle for pushing the stack of racks once loaded onto the dolly. Dollies are also used to transport racks of dirty dishes or glassware.
Most of these dollies have a frame that is open in the center. While some dollies have a closed bottom, that is uncommon. The more likely scenario when clean or dirty dishes and glasses are transported in a dolly is that water or other substances pass right through the bottom of the racks, through the frame of the dolly and onto the floor over which the dolly is being pushed. Rather than just a single pool of water, use of a dolly with an open frame can lead to potentially hazardous spills all over the establishment, including areas of a restaurant where patrons may walk.
What is needed is an apparatus for preventing water or other substances that spill out of the bottom of a commercial dish or glassware rack from passing onto the floor below. A basin with a solid base and solid sides that is sized and configured to permit interlocking with commercial dish or glassware racks could be placed on the floor at the bottom of a stack of racks, or at the bottom of a dolly, permitting drips from the racks stacked above the basin to be caught by the basin. Further, placing a basin underneath the stack of racks would elevate the clean dish and glassware further from the floor. A beneficial increase in workplace safety and sanitation is a likely result of use of such a device.
Accordingly, this application discloses a basin for use with commercial dish and glassware racks.
FIELD OF THE INVENTION
This invention relates generally to commercial dishwashers, and more specifically, to a basin for use with commercial dish and glassware racks.
SUMMARY
This invention relates generally to commercial dishwashers, and more specifically, to a basin for use with commercial dish and glassware racks. In some embodiments, a basin for use with commercial dish and glassware racks may include a four-sided base and a plurality of sides or side walls peripheral to the base. In some embodiments, the base is a square base, having four corners of approximately ninety degrees each. In some embodiments, a side is defined by an inner panel and an outer panel, the inner and outer panels being associated with a top rail of the basin, where pairs of adjoining sides form a corner. In some embodiments a corner is a rounded corner. In some embodiments, a basin for use with a commercial dish and glassware rack has area dimensions defined as the area disposed between the plurality of outer panels of approximately 19.72″ by 19.72″.
In some embodiments, a basin for use with commercial dish and glassware racks has a base having a top surface of the base and a bottom surface of the base. The top surface forms a floor of the basin, with the plurality of inner panels of the basin completing the interior of the basin. In some embodiments, the interior assemblies of the basin are solid, preventing the passage of water or other substances through the interior of the basin.
In some embodiments of a basin for use with commercial dish and glassware racks, each pair of an inner panel and an outer panel are panels which are upwardly inclined towards one another. In some embodiments, each pair of an inner panel and an outer panel are panels that define a space within the panels. In such an embodiment, one or more basins or commercial dish and glassware racks can be stacked and removably interlocked, such that a top rail of a commercial dish or glassware rack or a top rail of a basin can fit inside the space defined by the inner panel and outer panel. In such an embodiment, the space defined by the inner panel and outer panel receives the top rail of a basin or the top rail of a commercial dish or glassware rack, such that the commercial dish or glassware rack is “stacked” upon the basin in a removably interlocked fashion. In such an embodiment, the upward inclination of the inner panel and outer panel towards one another limits the penetration of a rack that is stacked below the basin into the space defined by basin the inner panel and outer panel of the basin.
In some embodiments, if a commercial dish or glassware rack is stacked on the basin and said commercial dish or glassware rack contains dishes or glassware that are wet or otherwise contaminated with liquids or other substances, drips containing water or other substances are caught by the basin.
In some embodiments, a basin for use with commercial dish and glassware racks includes a plurality of circular indentations in the top surface of the base of the basin. Such circular indentations trap water or other substances which have dripped from a commercial dish or glassware rack that is stacked above the basin. The circular indentations are compartment-like indentations that prevent water or other substances from freely flowing around the basin. The circular indentations trap liquids in a more contained fashion than a basin without such indentations.
In some embodiments, a basin for use with commercial dish and glassware racks includes one or more handle sections. In some embodiments, a basin for use with commercial dish and glassware racks includes one or more locator posts projecting upwardly from the top rail. A locator post is designed to be received by a portion of a channel of the bottom surface of a basin, or to be received by a portion of a channel of the bottom surface of a commercial dish and glassware rack. In some embodiments, the locator posts are curved locator posts, where the curve follows the curve of rounded corners of the basin. In a further embodiment, a basin for use with commercial dish and glassware racks is fabricated of heat-stable co-polymer plastic.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention are described in detail below with reference to the following drawings:
FIG. 1 is a depiction of the prior art, in this case, a perspective view of an exemplary glassware rack for use with a commercial dishwasher;
FIG. 2 is a depiction of the prior art, in this case, a perspective view of exemplary glassware being loaded into an exemplary glassware rack for use with a commercial dishwasher;
FIG. 3 is a depiction of the prior art, in this case, a cutaway lateral view of exemplary glassware that has been loaded into an exemplary glassware rack for use with a commercial dishwasher;
FIG. 4 is a depiction of the prior art, in this case, an exploded perspective view of exemplary glassware being loaded an exemplary glassware rack for use with a commercial dishwasher that is interlockably stackable with a different exemplary glassware rack for use with a commercial dishwasher;
FIG. 5 is a depiction of the prior art, in this case, a cutaway lateral view of an exemplary stack of exemplary glassware racks for use with a commercial dishwasher, said racks having been loaded with exemplary glassware, said glassware dripping water or other substances through the bottom of the racks, the water or other substances being dripped directly onto the floor;
FIG. 6 is a depiction of the prior art, in this case, a perspective view of an exemplary dolly for use in transporting an exemplary stack of exemplary commercial dish or glassware racks for use with a commercial dishwasher;
FIG. 7 is a depiction of the prior art, in this case, a perspective view of exemplary glassware being loaded an exemplary glassware rack for use with a commercial dishwasher that is interlockably stackable with a different exemplary glassware rack for use with a commercial dishwasher in an exemplary stack, the exemplary stack being loaded on an exemplary dolly;
FIG. 8 is a depiction of the prior art, in this case, a perspective view of an exemplary stack of a plurality of exemplary glassware racks for use with a commercial dishwasher, the exemplary stack of racks having been placed on an exemplary dolly, the racks having been loaded with exemplary glassware, said glassware dripping water or other substances through the bottom of the racks and through the frame of the dolly, said water or other substances being dripped directly onto the floor;
FIG. 9 is a perspective view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 10 is a side view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 11 is a top view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 12 is a bottom view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 13 is a partial perspective cutaway of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 14 is a partial lateral cutaway view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 15 is a perspective view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 16 is a perspective view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 17 is a lateral cutaway view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 18 is a lateral cutaway view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention;
FIG. 19 is a perspective view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention; and
FIG. 20 is a perspective view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
This invention relates generally to commercial dishwashers, and more specifically, to a basin for use with commercial dish and glassware racks. Specific details of certain embodiments of the invention are set forth in the following description and in FIGS. 1-20 to provide a thorough understanding of such embodiments. The present invention may have additional embodiments, may be practiced without one or more of the details described for any particular described embodiment, or may have any detail described for one particular embodiment practiced with any other detail described for another embodiment.
FIG. 1 is a depiction of the prior art, in this case, a perspective view of an exemplary glassware rack for use with a commercial dishwasher. Commercial dish and glassware racks and their use are well understood in the art. An exemplary glassware rack 100 may include a plurality of side walls one of which is at 104 ; a plurality of inner panels one of which is at 106 ; a plurality of outer panels one of which is at 108 ; a top rail at 110 ; a plurality of corners one of which is at 112 ; a plurality of handle sections one of which is at 114 ; a plurality of small ridges one of which is at 116 ; a plurality of gripping areas one of which is at 118 ; a plurality of side openings one of which is at 120 ; a network area at 122 for receiving dishware, glassware, tableware, or other items to be washed by the commercial dishwasher; and a frame at 124 , for making compartments into which one or more items to be washed by the commercial dishwasher can be placed. Of note is the plurality of openings in the side of the exemplary glassware rack, designed to permit water to pass into and out of the glassware rack. The base of the rack also has a plurality of openings designed to permit water to pass into and out of the glassware rack.
FIG. 2 is a depiction of the prior art, in this case, a perspective view of exemplary glassware being loaded into an exemplary glassware rack for use with a commercial dishwasher. An exemplary glassware rack 100 can have glasses 126 placed into the network area 122 through the top of the glassware rack 100 . Of note is that the glassware is loaded upside-down, so that water penetrating the rack from the washing mechanism of the commercial dishwasher below the rack can enter the glassware for cleaning. Also, the upside-down orientation permits water or other substances to drip out of the upside-down glassware.
FIG. 3 is a depiction of the prior art, in this case, a cutaway lateral view of exemplary glassware that has been loaded into an exemplary glassware rack for use with a commercial dishwasher. An exemplary glassware rack 100 may include a base at 102 , a plurality of inner panels one of which is at 106 ; a plurality of outer panels one of which is at 108 ; a channel at 128 ; a plurality of limiting spacers one of which is at 130 , the limiting spacers each having a bottom edge of the limiting spacer, one of which is at 132 . Of note is that an exemplary glassware rack 100 may have a channel 128 in the bottom surface of the base that is formed by the interior surface of the inner panel 106 (interior here meaning interior to the channel), the interior surface of the outer panel 108 (interior here meaning interior to the channel), and the plurality of bottom edges of the limiting spacers 132 . The channel 128 is disposed adjacent to the outer panel 108 of each of the four sides peripheral to the base 102 , where the channel 128 is adapted for receiving at least a portion of a top rail 110 of another commercial dish and glassware rack 100 . The inner panel 106 and outer panel 108 of each of the four sides define a space with a plurality of limiting spacers 130 positioned therein. The plurality of limiting spacers 130 are positioned to limit the penetration of at least a portion of a top rail 110 of another commercial dish and glassware rack 100 during stacking.
FIG. 4 is a depiction of the prior art, in this case, an exploded perspective view of exemplary glassware being loaded an exemplary glassware rack for use with a commercial dishwasher that is interlockably stackable with a different exemplary glassware rack for use with a commercial dishwasher.
FIG. 5 is a depiction of the prior art, in this case, a cutaway lateral view of an exemplary stack of exemplary glassware racks for use with a commercial dishwasher, said racks having been loaded with exemplary glassware, said glassware dripping water or other substances through the bottom of the racks, the water or other substances being dripped directly onto the floor. The base 102 of an exemplary glassware rack 100 has a plurality of openings, similar to the plurality of openings 120 in the plurality of sides 104 in the rack 100 . Of note in FIG. 5 , it is clear that water 134 or other substances including unconsumed beverages can drip from the inside of the glasses 126 through the holes in the base 102 onto the floor 136 or other surface on which the rack 100 or stacked racks rest. The resulting puddle creates a safety hazard for employees or others working near the stack of racks 100 .
FIG. 6 is a depiction of the prior art, in this case, a perspective view of an exemplary dolly for use in transporting an exemplary stack of exemplary commercial dish or glassware racks for use with a commercial dishwasher. Dollies for transporting a stack or commercial dish or glassware racks and their use are well understood in the art. An exemplary dolly 200 may include a frame at 202 ; a lip at 204 , a plurality of wheels, one of which is at 206 , and a handle at 208 . The frame 202 and lip 204 are configured and dimensioned to removably receive a commercial dish or glassware rack. The inside dimensions of the frame 202 are just large enough to accommodate a 19.72″ by 19.72″ rack, while the lip 204 provides the surface on which the rack rests. Of note in FIG. 6 is that the exemplary dolly 200 has an open frame. It will be recognized by one with skill in the art that a dolly such as the exemplary dolly 200 , when loaded with racks full of wet dish and glassware, will permit drips from the wet dish and glassware to pass directly through the rack onto the surface below on which the dolly is being rolled.
FIG. 7 is a depiction of the prior art, in this case, a perspective view of exemplary glassware being loaded an exemplary glassware rack for use with a commercial dishwasher that is interlockably stackable with a different exemplary glassware rack for use with a commercial dishwasher in an exemplary stack, the exemplary stack being loaded on an exemplary dolly.
FIG. 8 is a depiction of the prior art, in this case, a perspective view of an exemplary stack of a plurality of exemplary glassware racks for use with a commercial dishwasher, the exemplary stack of racks having been placed on an exemplary dolly, the racks having been loaded with exemplary glassware, said glassware dripping water or other substances through the bottom of the racks and through the frame of the dolly, said water or other substances being dripped directly onto the floor. Of note in FIG. 6 is the water 134 passing through the frame 202 . The water 134 can come to rest on a floor or other surface on which the dolly 200 is being rolled over or resting, creating a spill hazard for employees or patrons who may walk in the path of the dolly 200 .
FIGS. 9, 10, and 11 are a perspective view, a side view, and a top view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. In some embodiments, a basin for use with commercial dish and glassware racks 300 may include a four-sided base 302 and a plurality of sides or side walls peripheral to the base, one of which is shown at 304 . In some embodiments, the base is a square base, having four corners of approximately ninety degrees each. In some embodiments, a side 304 is defined by an inner panel 306 and an outer panel 308 , the inner and outer panels being associated with a top rail 310 of the basin 300 , where pairs of adjoining sides form a corner one of which is depicted at 312 . In some embodiments a corner 312 is a rounded corner 312 . In some embodiments, a basin for use with a commercial dish and glassware rack 300 has area dimensions defined as the area disposed between the plurality of outer panels 308 of approximately 19.72″ by 19.72″. In different embodiments, a basin for use with a commercial dish and glassware rack 300 is not a square basin. In different embodiments, a basin for use with a commercial dish and glassware rack 300 has different lengths or widths, the length or width ranging from 2 inches to 144 inches.
In some embodiments, a basin for use with commercial dish and glassware racks 300 has a base 302 having a top surface 324 of the base and a bottom surface (not depicted in FIG. 9, 10 or 11 ) of the base. The top surface 324 forms a floor of the basin 300 , with the plurality of inner panels 306 of the basin 300 completing the interior of the basin 300 . In some embodiments, the interior assemblies of the basin 300 are solid, preventing the passage of water or other substances through the interior of the basin 300 .
In some embodiments of a basin for use with commercial dish and glassware racks 300 , each pair of an inner panel 306 and an outer panel 308 are panels which are upwardly inclined towards one another. In some embodiments, each pair of an inner panel 306 and an outer panel 308 are panels that define a space within the panels. In such an embodiment, one or more basins 300 or commercial dish and glassware racks can be stacked and removably interlocked, such that a top rail of a commercial dish or glassware rack or a top rail 310 of a basin can fit inside the space defined by the inner panel 306 and outer panel 308 . In such an embodiment, the space defined by the inner panel 306 and outer panel 308 receives the top rail 310 of a basin or the top rail of a commercial dish or glassware rack, such that the commercial dish or glassware rack is “stacked” upon the basin in a removably interlocked fashion. In such an embodiment, the upward inclination of the inner panel 306 and outer panel 308 towards one another limits the penetration of a rack that is stacked below the basin 300 into the space defined by basin the inner panel 306 and outer panel 308 of the basin 300 .
In some embodiments, if a commercial dish or glassware rack is stacked on the basin 300 and said commercial dish or glassware rack contains dishes or glassware that are wet or otherwise contaminated with liquids or other substances, drips containing water or other substances are caught by the basin 300 .
In some embodiments, a basin for use with commercial dish and glassware racks 300 includes a plurality of circular indentations 320 in the top surface 324 of the base 302 of the basin 300 . Such circular indentations 320 trap water or other substances which have dripped from a commercial dish or glassware rack that is stacked above the basin 300 . The circular indentations 320 are compartment-like indentations that prevent water or other substances from freely flowing around the basin 300 . The circular indentations 320 trap liquids in a more contained fashion than a basin without such indentations.
In some embodiments, a basin for use with commercial dish and glassware racks 300 includes one or more handle sections, one of which is depicted at 314 . In some embodiments, a basin 300 may have a handle section 314 only on two opposing sides 304 , or may have a handle section on all four sides. A handle section 314 includes a small ridge 316 “cut out” of an outer panel 308 with which the handle section 314 is associated. A handle section includes a gripping area 318 intended to be gripped by one who carries a basin 300 .
In some embodiments, a basin for use with commercial dish and glassware racks 300 includes one or more locator posts projecting upwardly from the top rail 310 , one of which is located at 322 . A locator post 322 is designed to be received by a portion of a channel of the bottom surface of a basin 300 , or be received by a portion of a channel of the bottom surface of a commercial dish and glassware rack. It will be recognized by one skilled in the art that locator posts 322 , which are generally upward protrusions from a top rail 310 , may vary in size, shape, or location on the top rail. In some embodiments, locator posts 322 projecting upwardly from the top rail are L-shaped. In a further embodiment, the L-shaped locator posts project upwardly from the top rail at the four corners. In a different embodiment, the locator posts 322 are curved locator posts 322 , where the curve follows the curve of rounded corners 312 of the basin 300 . In some embodiments, locator posts 322 may be non-uniform or non-symmetrical in appearance. In some embodiments, locator posts 322 may have functional shapes that limit the stackability of one or more basins 300 or dish and glassware racks to a particular rotation.
In a certain embodiment, a basin for use with commercial dish and glassware racks 300 is fabricated of plastic. In a further embodiment, a basin for use with commercial dish and glassware racks 300 is fabricated of heat-stable plastic. In a further embodiment, a basin for use with commercial dish and glassware racks 300 is fabricated of heat-stable co-polymer plastic. Such plastics and their selection are well known to those skilled in the art.
It will be appreciated by those with skill in the art that the terms “basin for use with commercial dish and glassware racks,” as used in the instant application including in the preamble to the claims, does not limit the function of the apparatus to being a basin, nor does it limit its use to accompany commercial dish or glassware racks. Use of the term “basin for use with commercial dish and glassware racks” in any claim preambles is not intended to give life, meaning, or vitality to the claims.
FIG. 12 is a bottom view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. FIG. 13 is a partial perspective cutaway of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention.
In some embodiments, a basin for use with commercial dish and glassware racks 300 may include a base 302 , the base having a bottom surface 326 of the base 302 ; a plurality of sides one of which is at 304 , the sides 304 being defined by a plurality of inner panels one of which is at 306 and a plurality of outer panels one of which is at 308 ; a plurality of corners one of which is at 312 ; a plurality of handle sections, one of which is at 314 (not shown in FIG. 13 ), the handle sections 314 each having a gripping area at 318 ; a channel 328 ; a plurality of limiting spacers, one of which is at 330 , the limiting spacers 330 each having a bottom edge of a limiting spacer, one of which is at 332 ; a plurality of short limiting spacers one of which is at 334 , the short limiting spacers 334 each having a bottom edge of a short limiting spacer, one of which is at 336 ; and a square indentation area 338 .
In some embodiments, a basin 300 includes a channel 328 , which is disposed adjacent to the interior side of the outer panel 308 , the channel 328 completely circumscribing the base 302 of the basin 300 . In some embodiments, a channel 328 is defined by a space within the inner panel 306 and the outer panel 308 . In a further embodiment, the channel 328 defined by the space within the inner panel 306 and the outer panel 308 is further defined by a plurality of limiting spacers 330 disposed between the inner panel 306 and the outer panel 308 . The limiting spacers 330 do not extend to the bottom of the base 302 , and the difference between the bottom of the base 302 and the bottom of the limiting spacers 330 defines the limit of penetration of at least a portion of a top rail 310 of another basin 300 or a commercial dish and glassware rack stacked underneath a basin 300 . In a further embodiment, the channel 328 is further defined by a plurality of short limiting spacers 334 disposed between the inner panel 306 and the outer panel 308 . In such embodiments, when a different basin 300 or a commercial dish or glassware rack is stacked with the first basin 300 , the short limiting spacers 334 are configured to receive a locator post 322 of a basin 300 or a locator post of a commercial dish or glassware rack. It will be apparent to one with skill in the art that a basin 300 having locator posts 322 located in the corners 312 of the basin 300 is stacked underneath a different basin 300 , the short limiting spacers 334 nearest the corners 312 of the basin 300 will engage the locator posts 322 .
In some embodiments, the bottom surface 326 of a base 302 of a basin 300 has a square indentation 338 . In such embodiments, when a dish or glassware rack holding dishes or glassware is stacked underneath a basin 300 , with the dishes or glassware extending above the top rail of the dish or glassware rack below the basin 300 , a square indentation 338 can accommodate at least a portion of the dishes or glassware such that the dishes or glassware in the rack stacked underneath the basin 300 do not touch the bottom surface 326 of the basin 300 .
FIG. 14 is a partial lateral cutaway view of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. In some embodiments, a basin for use with commercial dish and glassware racks 300 has a channel 328 , the channel 328 being defined by a portion of the outer panel 308 , the inner panel 306 , the plurality of limiting spacers 330 , and the plurality of short limiting spacers 334 . In a certain embodiment, the channel 328 is configured to receive the top rail 310 of another basin 300 , the another basin 300 being represented in dashed lines in FIG. 14 . The channel 328 can also receive the top rail of a commercial dish and glassware rack. In some embodiments, the channel 328 receiving the top rail 310 facilitates the stacking of a plurality of basins 300 , or a stack including a plurality of basins 300 and/or a plurality of commercial dish and glassware racks. In some embodiments, the channel 328 limits the penetration into the base of the basin 300 by the top rail of another basin 300 or the top rail of another other rack. The top rail 310 of the lower basin 300 or other rack engages the bottom edge of the limiting spacers 332 , limiting the penetration. Further, for basins 300 or racks with locator posts 322 protruding upwardly from the top rail 310 , the locator posts 322 of the lower basin 300 or rack will engage the bottom edge of the short limiting spacers 336 of the upper basin 300 , further limiting the penetration. Further, the locator posts 322 , when received by the channel 328 and engaging the bottom edge of the short limiting spacers 336 and the interior portion of the inner panel 306 of the upper basin 300 , will serve to further limit the lateral travel of the plurality of racks or basins 300 with respect to one another, creating a more secure interlock when the locating posts 322 are part of the embodiment. Those skilled in the art will appreciate that many combinations of limiting spacers, short limiting spacers, top rails, and locator posts protruding upwardly from the top rail are possible, thus changing the degree of penetration of a lower basin 300 or rack into the base of an upper basin 300 or rack. Further, those skilled in the art will appreciate that such combinations can also limit stacking of basins 300 or racks to certain orientations, for example, such that when a rack is rotated 90 degrees the penetration (and thus, the height difference between the top surfaces of the bases of the racks) is varied.
FIGS. 15 and 16 are perspective views of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. In some embodiments, a commercial dish or glassware rack 100 is stacked on top of a basin for use with commercial dish and glassware racks 300 . In a certain embodiment, the top rail 310 (not seen in FIG. 16 ) of the basin 300 is received by a channel in the commercial dish or glassware rack 100 , said channel being common to all commercial dish or glassware racks as described herein. In some embodiments, a plurality of commercial dish or glassware racks 100 are stacked above a basin 300 . In a further embodiment, glasses 126 are loaded upside-down into the exemplary glassware rack 100 . Should the glasses 126 be wet or contain other substances due to either being washed without drying, or containing unconsumed beverages, any drips from the glasses 126 will drip into the basin 300 , preventing the spillage of the water or other substances onto the surface below the glassware rack 100 . Further, carrying a rack 100 with a basin 300 underneath will ensure drips will not drip onto the clothing of the person carrying the rack. Further, when use of the basin 300 has ended, the basin 300 can quickly be cleaned by rinsing it with water, or even by running it upside-down through the commercial dishwasher.
In a different embodiment, a basin 300 is stacked on top of another basin 300 . Such stacking of a plurality of basins 300 could be desirable for storage of the basins, or for creating a stack of basins 300 on top of which a commercial dish or glassware rack 100 is stacked, to raise the height of the commercial dish or glassware rack 100 for easy loading or unloading. Those skilled in the art will appreciate that are many uses for a basin 300 beyond catching drips from dishes or glassware that are not dry.
FIGS. 17 and 18 are lateral cutaway views of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. In some embodiments, when a plurality of dish and glassware racks 100 are stacked on top of a basin for use with commercial dish and glassware racks 300 , water drips 134 or other substances from the dishes and glassware in the racks 100 drip through the holes in the base of the rack 102 into the basin 300 . The water 134 or other substances having dripped from the glasses 126 or other items in the racks 100 is contained by the basin 300 , being accumulated on the top surface 324 of the base 302 of the basin. In some embodiments, a plurality of basins 300 and commercial dish and glassware racks 100 are stacked together, alternating a basin 300 with a plurality of racks 100 . In this embodiment, water 134 dripping from racks 100 is spread among multiple basins 300 .
FIGS. 19 and 20 are perspective views of a basin for use with commercial dish and glassware racks, in accordance with an embodiment of the invention. In some embodiments, a basin for use with commercial dish and glassware racks 300 is received by a dolly 200 . In a further embodiment, one or more commercial dish and glassware racks 100 are stacked above the basin 300 . In such an embodiment, racks 100 holding dishes or glassware that is wet or to which remnants of food or drinks or other substances are adhered can be safely transported by the dolly 200 without fear that the water or other substances will drip through the racks 100 and dolly 200 onto the surface over which the dolly 200 is being pushed. Water or other substances may drip from the racks 100 , but it will be contained by the basin 300 that has been placed in the dolly 200 at the bottom of the stack of racks 100 .
While preferred and alternative embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of these preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow. | A basin which stackably interlocks with 20-inch square racks that hold dish and glassware washed in commercial dishwashers. The basin has substantially the exterior configuration of a commercial dishwasher rack and receives a plurality of dishwasher racks stacked above. The basin solid on its base and sides for prohibiting substances which drip down into it from racks stacked above from dripping onto the floor. The basin has circular indentations in the top surface of the base, trapping water and preventing it from sloshing from side to side of the basin when it is carried or moved. The basin may be loaded into a dolly used to transport commercial dishwasher racks, as the dollies typically have an open bottom. Thus, the basin can provide the water-catching function for racks loaded onto a dolly. Grooves in the basin's bottom surface permit stacking on top of a rack or other basins for storage. | 0 |
The present application is a continuation-in-part of Ser. No. 587,116, filed Sept. 24, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a portable clothes line unit, and more particularly to a portable clothes line device with clothes line units extendable along fold up rods extending from a base housing unit.
Conventional clothes lines which are designed for use in confined areas generally consist of spring-loaded rollers which dispense a set of cords to a desired second location. One notable drawback of this type of arrangement resides in the inability to always reach a convenient or desired second location. A second drawback of this type of arrangement resides in the inability to accommodate the use of the clothes lines to the existing washing load as all of the clothes lines of the prior art generally must be drawn out or extended.
In trying to overcome the limitations in prior art devices other arrangements have included pulling a number of wound-up clothes lines out from a central bracket member with pivoting rods. These types of devices are difficult to use without dangerously reaching out over the clothes lines when such devices are used on a window ledge or high railing or bannister.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of devices now present in the prior art, the present invention provides an improved portable clothes line. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved portable clothes line device. To attain this the present invention has individual clothes line units stored within a central housing which is mounted on a window ledge, railing or bannister. The clothes line units are cranked out from the central housing in a parallel arrangement to the housing along channels in rods folded out from the housing ends.
This together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of the invention in use.
FIG. 2 is a similar view with the invention in its folded up configuration.
FIG. 3 is a sectional view of the invention along the line 3--3 of FIG. 4A.
FIG. 4A is a top plan view of the portable clothes line device depicted in FIG. 1 fully extended.
FIG. 4B is a top plan view of the portable clothes line device depicted in FIG. 1 partially folded.
FIG. 5 is an elevational view of a clothes line unit used in the present invention.
FIG. 6 is a perspective view in section along the lines 6--6 of FIG. 5 of a clothes line unit connected to a rod.
FIG. 7 is a partial sectional view of FIG. 4A.
FIG. 8 is a rear sectional view of the housing member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown a portable clothes line device 1 incorporating the principle features of the present invention. The invention 1 has a brace housing 10, two lateral support rods 29 and 30, and a plurality of individual clothes line units 50.
The brace housing 10 has a rectangular vertical housing member 11 with a top 12, two sides 13, a bottom 14, a front face 15 and a rear face 16. The housing member 11 has two short support stubs 19 and 20 attached to the housing member sides 13 near to the housing member top 12 and extending in the same direction perpendicular and horizontally out from the housing member front face 15. The unattached outer ends 21 of the stubs 19 and 20 terminate in pivotal joints 22. Lateral support rods 29 or 30 are joined to each pivotal joint 22. In one position, the support rods 29 and 30 extend horizontally outward from the pivotal joints 22 in the same longitudinal axis as their corresponding stub 19 or 20. In their alternate position, the lateral support rods 29 and 30 are folded 90 degrees inward toward the vertical housing member 11. The support stubs 19 and 20 and corresponding support rods 29 and 30 are of different lengths for compactness when the invention 1 is fully folded. See FIG. 2. The left stub 19 is longer than the right stub 20. However, the left rod 29 is shorter than the right rod 30, so that the invention 1 is symmetrical when fully opened. See FIGS. 1, 2 and 4A.
Each stub 19, 20 has a downwardly projecting projecting vertical brace member 23 attached to its underside 24 toward its outer end 21, just before the pivotal joint 22. The brace members 23 and vertical housing 11 interconnected by the stubs 19 and 20 form a downwardly projecting "U" shaped brace 3 which when placed over a window sill, bannister or railing hold the invention in place. An adjustment screw 25 in each of the vertical brace members 23 provides means for tightly securing the invention 1 to a window sill, bannister or railing.
The stubs 19, 20 and support rods 29, 30 have coincident grooved "T" shaped channels 26 and 31 along the longitudinal axis of their inner sides 27 and 32. The channels 26 and 31 in the left stub 19 and left support rod 29 form a left channel 40. The channels 26 and 31 in the right stub 20 and support rod 30 form a right channel 41. The left 40 and right 41 channels thereby formed face each other. Within each channel 40 and 41 there is placed a number of slidable T-shaped line holders 51. Each holder 51 in the left channel 40 has one end 53 of a length of clothes line 52 attached thereto. The other end 54 of each length of clothes line 52 is attached to a corresponding holder 51 in the right channel 41. A clothes line unit 50 is formed by one length of clothes line 52 with a holder 51 at each line end 53 and 54.
Each lateral support rod 29, 30 and support stub 19, 20 has a slidable, interconnected bolt 45 for bracing the lateral support rods 29, 30 in the extended position. Each rod 29, 30 has a vertical clamp 47 attached thereto near to the pivotal joints 22. Each support stub 19, 20 has two vertical clamps 47 attached thereto, one adjacent to the pivotal joints 22 and the second a short distance away toward the housing member 11. The slid bolt 45 is slidably secured within the support stub clamps 47. A handle 46 attached to the slid bolt 45 prevents the slid bolt 45 from sliding completely out of its position within the two stub clamps 47. When the lateral support rods 29, 30 are folded up, the slid bolts 45 are slid rearward toward the housing member 11. When the lateral support rods 29, 30 are in the extended position, the slid bolts 45 are slid forward so that the forward end of each bolt 45 engages the clamps 47 attached to the support rods 29, 30. This action, locks the lateral support rods 29, 30 in the extended position.
The holders 51 in the left channel 40 are interconnected to each other in a pulley arrangement in the same fashion as a drapery pulley. The holders 51 in the right channel 41 are interconnected in the same manner.
As may be best understood from FIGS. 4A, 5, 6, 7 and 8, the crank 5 in this embodiment a crank 5 centrally located on the vertical housing top 12 is extended by a rod 56 to a horizontally positioned bevel gear 67. Turning the crank 5 will cause the bevel gear 67 to turn in a horizontal plane. The crank gear 67 engages a vertically positioned drive rod bevel gear 68 through which a drive rod 65 is positioned and attached. As the crank gear 67 is turned, it causes the drive rod gear 68 to turn through a vertical plane thereby causing the drive rod 65 to radially rotate. The drive rod 65 is positioned in a horizontal plane extending from one housing side 13 to the other 13. The drive rod ends are rotatably seated within sockets 66 attached to insides of the housing sides 13. Two pulley ropes 60 and 61 engage each drive rod side 62 and 63, respectively. Each pulley rope 60, 61 is adaptively engaged to the drive rod 65 so as to act as a loop. Each pulley loop 60, 61 passes by a guide wheel 69 and sequentially connects to each T-shaped holder 51 in their respective channels 40, 41. After the last holder 51 is attached, the each respective loop 60, 61 passes over a guide wheel 64 locates at the farthermost point 42, 43 of each lateral rod 29, 30. Each loop 60, 61 is then brought directly back to the drive rod 65. The loop arrangement about the drive rod 65 avoids conflicts between and provides mutual support when the holders 51 are being slid outwardly or inwardly along the channels 40 and 41. When the support rods 29 and 30 are to be folded in toward the housing member 11, the line holders 51 are first retracted into the stub channels 26, and then optionally into the vertical housing member 11. When the support rods 29 and 30 are extended into their outward lateral positions, the crank 5 is used to extend the clothes line units 50 out onto the support rod channels 31. This permits a user to load clothing onto one line 52 at a time before extending a clothes line unit 50 out onto the support rods 30. This avoids the dangers of prior art devices whereby users must dangerously lean out a window or other a bannister or railing to load clothing onto a clothes line. Since wet clothing is heavy, the invention is much easier to use as less muscle power is needed to load clothing onto a clothes line immediately outside a window than to extend out from the window and attempt to load wet clothing onto a line further out from the window. Removal of the clothing when it is dry is also consequently easier. Only as many lines 52 as are necessary to accommodate a particular wash load need to be used in the present invention 1. The unused line units 50 would remain in their retracted positions.
It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof. The hand crank 5 shown in the preferred embodiment could easily me replaced with an electric motor. | A new and improved portable clothes line. Individual clothes line units are stored within a central housing which is mounted on a window ledge, railing or bannister. The clothes line units are cranked out from the central housing in a parallel arrangement to the housing along channels in rods folded out from the housing ends. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a sizing agent-free tangled multifilament yarn.
2. Description of Related Art
Tangled multifilament yarns are sufficiently familiar. They are generally manufactured by means of blowing with a fluid, preferably air. The disadvantage of normal tangled multifilament yarns is that they lend themselves only conditionally to subsequent processing. For example, if tangled multifilament yarns are employed as warp yarns in weaving, they are subject to a large number of stresses, as portrayed in detail in the introduction to DE-A-43 27 371. In order to limit these stresses such that as few disruptions as possible arise during weaving, this specification recommends the use of stabilized sizing agent-free multifilament yarns. All multifilament yarns are considered to be stabilized which, under the warp thread tensions occurring as a result of the stresses on the loom and even in the plain weave L1/1, which is classified as particularly critical, can be worked with practically no disruptions with high end spacing, e.g., with an end spacing of 40/26 threads per cm warp/weft, not only on traditional loom systems, but most especially on modern loom systems based on weft insertion via air or water. According to DE-A-43 27 371, all yarns which only possess protective twist and which are rubbed, heat-sealed, glued, melted together or, more especially, intermingled, are suitable for use as stabilized multifilament yarns. In order to weave the yarns described therein, care must be taken that the thread tension of the multifilament yarn does not exceed 1 cN/dtex throughout the processing and until it passes through the weaving reed. Thus, in DE-A-43 27 371, no mention is made of a special method by which a multifilament can be especially well stabilized, but instead it is pointed out that evidently the usual yarns can be used, as long as the thread tension of the yarns is selected low enough during subsequent processing. However, since the thread tensions in looms, especially in looms based on weft insertion via air or water, are predetermined by the construction of the machine and can only be influenced to a small degree, the method suggested therein seems hardly to be practicable.
Another well-known method of making multifilament yarns suitable for weaving consists of providing the multifilament yarns with sizing agents in a separate step prior to weaving, which must, however, be washed out of the finished fabric again after weaving. JP-A-52 63 334 makes known, for example, the method of initially tangling the multifilament yarns in order to obtain an opening length of 2 to 5 cm (20 to 50 knots per meter), after which they are provided with sizing agent amounting to 0.5 to 3%. As a separate process step is necessary for applying the sizing agent, i.e., sizing cannot be combined with the process steps required for manufacturing and subsequent processing, sized yarns are very expensive to manufacture. As already explained, an additional step, namely, removal of the sizing agent, is also required after weaving. In addition, in a further expensive step, the sizing agent must then be removed from the washing water in order to protect the environment.
Furthermore, JP-A-41 63 336 makes known the method of adding waxes such as carnauba wax, beeswax or candelilla wax to the sizing agent which is applied to the tangled multifilament yarns. By mixing sizing agent with wax, however, processing the washing water with which the sizing agent is washed out of the finished fabric, becomes even more expensive.
SUMMARY OF THE INVENTION
An object of this invention is at least to reduce the disadvantages described above.
This task is solved by a sizing agent-free tangled multifilament yarn with an opening length of 1 to 6 cm and a knot strength of no more than 2, at least the majority of whose filaments have a thin film consisting mainly of hard wax constituting about 0.3 to 2% of the total weight of the filaments together with this film, and are glued, at least in places, via this film to adjacent filaments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in conjunction with the following drawing wherein:
FIG. 1 is a schematic depiction of an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It is surprising to discover that the use of hard wax in tangled multifilament yarns alone results in good stabilization of these yarns. The knot strength is considered to be a measure of the quality of the stabilization.
The knot strength of a multifilament yarn is determined in the following manner, with reference to FIG. 1. The opening length T1 of a previously tangled multifilament yarn is first determined with a Rothschild Entanglement Tester NPT R-2070. Next, a bobbin (not shown) with the tangled multifilament yarn is fed to a device which simulates the stress in the weaving shed. For this purpose the yarn G is drawn off via an inflow galette 1 with separation roller 2 at a rate of 52.5 m/min., guided over a second galette 3 with separation roller 4 at a rate of 55 m/min., and then displaced via two thread guides 5 and 7 and a guide roller 6 in an elongated U. The length L of the arms of the U is 40 cm, while the separation between the arms of the elongated U is set to s=60 mm in the region between the thread guides 5 and 7 and to s'=25 mm in the region of the guide roller 6. After leaving the unshaped section, the yarn G is drawn off at a rate of 57.5 m/min. by a third galette 8 with separation roller 9. The numbers marked on galettes 1, 3 and 8 (3x, 6x and 8x respectively) signify that the yarn is looped repeatedly around the respective galette and its separation roller the equivalent number of times. For example, the yarn is placed around galette 3 and separation roller 4 so that the yarn loops around galette 3 and separation roller 4 six times.
Between the two arms of the elongated U, there is a central pivotally mounted beam 10 at both of whose ends a pin 11 made from ceramics (available under the commercial name Degussit) is arranged in such a fashion that when the beam 10 rotates, the yarn G is displaced by displacement d. The position of the yarn at maximum displacement is drawn with a dashed line and labeled G'. In the same way, beam 10 and the pins 11 in the position at which the yarn G is maximally displaced are drawn with dashed lines. Here, each separation t between pin 11 and axis 12 is 7.5 cm. While the yarn is drawn in a U shape through the measurement device, beam 10 is caused to rotate, whereby a constant rate of rotation of 100 l/min. is maintained. Next, the yarn G is wound on the bobbin again (not shown). The opening length T2 of this yarn G is determined in the same way as described above. The knot strength is hence determined as the quotient of T2 to T1.
Since generally by means of the dynamic stress applied to the yarn via pins 11 the opening length T2 of the yarn G is larger than the opening length T1 prior to treatment, values for the knot strength larger than 1 are generally obtained. However, it has also been observed that by means of the grazing stress of the ceramic pins 11, a shortening, albeit a slight one, of opening length T2 relative to T1 can occur. Thus generally values of more than 1, and in exceptional cases, values of 1 or less were determined in the measurement of the knot strength. In the experiments conducted to date, values of 0.8 or more were obtained.
Knot strength values of less than 1.0, such as 0.9 or 0.8, show clearly that among the yarns of the invention there are also yarns whose filament cohesion even improves during subsequent processing, for example, during weaving. Values of 1.0 for knot strength mean that the yarns behave in an extremely stable fashion during weaving, while the higher the knot strength value, the more the stability of the yarns increases and the lower the frequency of disruptions becomes.
It was surprising to discover that when weaving the yarns according to the invention, which are preferably used as warp yarns, practically no, or at any rate very few, thread breaks or other disruptions are seen during the weaving process, if by means of the hard waxes in the quantity specified according to the invention, a knot strength of less than 2, preferably less than 1.5, is set. Using conventional sizing agents such low values are almost impossible to achieve or can only be achieved at high cost, as will be shown below with the help of examples.
Here, multifilament yarns with a knot strength of 0.9 to 1.5 are preferably used.
Natural and synthetic hard waxes are suitable for the stabilization of tangled yarns. Among the synthetic hard waxes, polyethylene waxes and mixtures of the same with various molecular weights, which have been made well emulsifiable by means of aftertreatment processes with an oxidizing effect, are particularly worthy of mention.
Also suitable are mixtures of those hard waxes which do not cancel their hard wax properties. Thus, other components can also be admixed with the hard waxes, whereby the type and amount of the component must be selected such that the mixture obtained displays the typical properties of a hard wax. Soft waxes, such as beeswax, paraffin or usual textile wax, such as polyethylene oxide, cannot be used for the yarns according to the invention. However, they can be added to the hard wax employed according to the invention, in such small quantities that the latter do not lose their hard wax properties.
Other substances can also be admixed with the hard waxes employed according to the invention, such as smoothing agents or mixtures of viscous components. The hard waxes employed according to the invention or mixtures with hard waxes certainly contain no sizing agent, whose disadvantages were already described at the beginning. Although one skilled at the art is familiar with the usual sizing agents, usual sizing agents will be listed below. Usual sizing agents are agents such as those also described, for example, in JP-A-41 63 336, which are water-soluble and contain reaction products consisting of terephthalic or isophthalic acid, polyoxyethylene glycol, ethylene glycol, butylmethacrylate, laurylmethacrylate or mixtures of these.
The multifilament yarn according to the invention is particularly characterized by the fact that the film of the filaments consists of carnauba wax or synthetic hard wax, such as polyethylene wax. It is beneficial for the needle penetration of the hard waxes used, measured according to DIN 51579, to have values between <1 and 20. It is beneficial if these hard waxes have a melting range in the range of 65 to 120° C.
The task facing the invention is also solved by a method of manufacturing a multifilament yarn of this kind, in which the multifilament yarn is tangled, then moistened with a yarn cohesion agent and then wound up, which is characterized in that for the yarn cohesion agent, an aqueous emulsion is used which contains 10 to 20, preferably about 15 percent by weight, relative to the total weight of the emulsion, of a hard wax which may contain further additions such as emulsifiers, smoothing agents and/or anti-tack agents.
When the process of the invention is used it is not even necessary (leaving aside a few exceptions) to provide for a drying process after application of the emulsion and prior to winding up. In most cases, the thread rate during tangling is sufficient for the ambient air to remove so much moisture from the yarn covered with the emulsion that the now wound up yarn no longer sticks to adjacent yarn layers. The application can be included in a process normally present in manufacture. For instance, whenever tangling of the yarn is to take place at the end of the spinning process in the manufacture of POY or HOY yarns, treatment with the aqueous emulsion can take place directly following the tangle jet and prior to winding. The process according to the invention can therefore especially be applied as a process step integrated or capable of integration into the normal manufacture or subsequent processing of a yarn.
The process according to the invention is especially characterized by the fact that carnauba wax or synthetic hard wax such as polyethylene wax can be selected as the hard wax. Hard waxes with a needle penetration of <1 to 10 are especially preferred.
These waxes have admittedly already been employed in yarn processing, although these waxes were merely employed as additions to the familiar sizing agents, as proved by the specification JP-A-4163336 already mentioned above. It is surprising that now it has been discovered that excellently well stabilized multifilament yarns can be obtained without the use of sizing agent, merely by employing hard waxes. By this means, the expensive sizing process is no longer required. Since generally no drying is necessary either, the process according to the invention is also particularly economical. As sizing agent is no longer required, the process according to the invention is also particularly environmentally friendly.
The use of waxes is also, for example, known in blended yarns, as found in JP-A-61 194 249. In this specification, for yarns textured with false twist which consist of various groups of multifilament yarns, natural waxes are added to the same in order to improve their weavability. This may be possible for yarns textured with false twist. However, in the scope of this invention it was discovered that among the natural waxes recommended in JP-A-61 194 249, when used on tangled yarns the wool waxes and the paraffin waxes practically do not possess the stability required for the weaving process.
The invention will be explained in more detail with reference to the following examples.
EXAMPLES 1-12
Polyester cop yarns with a total titer of 150 dtex and 48 single filaments, containing a matting agent and with a round cross-section were used. These polyester cop yarns were coated using a ceramic jet with different quantities of 1% wax/emulsifier mixture and wound with no further drying. The drawing-off rate was 137 m/min., the distance between the location where coating was carried out (ceramic jet) and the winding was about 1 m. The aqueous wax emulsion employed had an active ingredient concentration of 6%.
After several days of conditioning in the air conditioning cabinet at 22° C. and 62% relative humidity, the treated yarns and for comparison the feed yarn were subjected to the extension-abrasion test described and the knot strength calculated as the ratio of the opening lengths T2 after and T1 prior to loading. The wax/emulsifier mixtures employed and the results of the measurements are given in Table 1. Here, in Examples 1 and 2 textile wax and paraffin wax respectively were employed, i.e., in both cases a wax which gives rise to a multifilament yarn which is not in accordance with the invention. Therefore, Examples 1 and 2 are comparative examples. In example 10, the proportion of hard waxes sunk below 0.3% so that here, too, a sufficient knot strength was not achieved. This is also a comparative example.
In the column headed Example in Table 1 the comparative examples are marked with (C). The column headed "T2/T1 without" shows the knot strength of the original yarn, i.e., the yarn not given a coating. All percentage values in the examples and in the table are relative to the total weight of the respective yarn. The waxes used are denoted in Table 1 with figures set in brackets. The description of the waxes is given below Table 1.
When the multifilament yarns according to Examples 1 and 2 were used as warp yarns, frequent breaks occurred during weaving, whereas when multifilament yarns according to each of Examples 3 to 11 were used as warp yarns, practically no breaks occurred.
The multifilament yarns according to the invention, which as described above were stabilized with suitable hard waxes to the level stated, can be processed as warp yarns to woven fabrics on traditional looms to good effect.
TABLE 1______________________________________ Opening length Knot T2/T1 Applied T1 T2 strengthExample Wax without % mm mm T2/T1______________________________________1 (C) (1) 5.1 1.0 20.6 107 5.192 (C) (2) 5.1 1.0 20.8 119 5.723 (3) 6.1 1.0 20.8 15.4 0.744 (3) 6.1 0.66 19.6 25.8 1.325 (3) 6.1 0.33 23.8 42.4 1.786 (4) 1.0 25.9 25.5 0.987 (5) 1.0 17.4 19.9 1.158 (6) 3.6 1.5 17.5 19.0 1.089 (6) 3.6 1.0 15.7 25.3 1.6110 (C) (6) 3.6 0.66 16.5 41.9 2.511 (7) 3.6 1.0 20.6 25.4 1.2312 (7) 3.6 0.66 15.0 22.7 1.51______________________________________ (1) Textile wax P, polyglycol ether (MW 600) with waxlike properties, manufactured by BASF. (2) Paraffin emulsion C, a mixture of 30 parts paraffin (melting pt. 51-53° C.), tallow alcohol × 6 E0, spin finish K 7334 (Stockhausen) and 10 parts aerosol OT (Cyanamid), respectively. (3) Aquacer 611, 35%, nonionogenic emulsion of carnauba wax in water, manufactured by BYKCERA bv; melting pt. 80-90° C. (Lit.) (4) 50% (1) and 50% (3) (5) Two parts (3) and one part Rewopal TA 25 S, tallow alcohol × 25 EO, manufactured by REWO/WITCO. (6) Ultralube W388, 30% nonionogenic emulsion consisting of about 15 part polyethylene waxes with various hardnesses and about 15 parts paraffin (melting pt./solid matter about 96° C.). (7) Ultralube W389, analogous to W388, but melting pt. of solid matter about 105° C., manufactured by KEIMADDITEC
EXAMPLES 13-16
In these examples, it is shown that the use of sizing agents to which a hard wax is added, as described in JP-A 41 63 336, gives a poorer result than the use of hard wax without sizing agent.
Wax (3) was again used as the hard wax. For the sizing agent, a reaction product consisting of terephthalic acid, sulfoisophthalic acid and glycols which can be obtained from Eastman under the name LB 100, was used. For the yarn, the yarn used in the previous examples was again used. The values for the original yarn have been included in the table under the heading "yarn". The quantity applied and the knot strength is shown in Table 2.
TABLE 2______________________________________ Size Knot mixture Size Applied strengthExample Hard wax % % % T2/T1______________________________________Yarn 0 0 0 3.113 0 100 1 1.214 25 75 1 1.815 50 50 1 2.716 100 0 1 1.03______________________________________
When comparing the data contained in Table 2, it emerges that the knot strength becomes poorer the larger the proportion of hard wax in the size is. It is thus all the more surprising to find that when only hard wax is applied, practically better knot strength is achieved than with sizing agent alone. If the yarn is drawn off the finished yarn package at a rate of 100 m/min., for the yarn according to Example 13, strongly varying stresses arise in the range of 0.63 to 1.06 cN, whereas for the yarn according to example 16 stresses only in the range of 0.25 and 0.3 cN were measured. Here, too, it becomes clear that the yarns treated with hard waxes according to the invention offer decided advantages. | Sizing agent-free tangled multifilament yarn with an opening length of 1 to 6 cm and a knot strength of no more than 2, at least the majority of whose filaments have a thin film consisting mainly of hard wax constituting about 0.3 to 2% of the total weight of the filaments together with this film, and are glued, at least in places, via this film to adjacent filaments. | 3 |
RELATED APPLICATIONS
This application is a continuation-in-part of my Application Ser. No. 397,305 filed Sept. 14, 1973 now U.S. Pat. No. 3,943,850.
FIELD OF THE INVENTION
The present invention relates to stencil duplicators and more particularly to assisting in removing stencils or ink screens from such machines. Stencils and ink screens are at present removed entirely by hand and it is an object of this invention to provide mechanical means for assisting the removal.
PRIOR ART
In U.S. Pat. No. 3,788,221 (Borneman) there is disclosed a fully automated printing machine which forms thermographically an image on a stencil corresponding to an image on an original, carries the stencil for repetitive printing operations, and automatically rejects the used stencils by feeding them between successive convolutions of a spiral build-up of blotting web on a take-up roll. When full, this blotting web roll is disposed of, thereby avoiding the need for the duplicator operator to handle the inked stencils after use. With this arrangement, there is need for a bulky reception means to hold both the take-up roll for blotting web and also the supply roll of the same blotting web. More importantly, such apparatus makes no provision for re-use of any of the stencils. Any stencil fed into this spiral of blotting web must be regarded as disposed of, and thus if, at some later date, it is desired to produce further copies with the same image, a fresh stencil would need to be cut.
With the increasing cost of printing materials, it is desirable to avoid disposing of a stencil until it is no longer of further use and accordingly one object of the present invention is to provide a stencil duplicator in which a stencil can readily be received and retained individually on a support member for subsequent disposal or transfer to storage.
A second object of the present invention is to provide a stencil duplicator including means for receiving and retaining one used ink screen either for disposal purposes or for storage during use with an alternative ink screen, for example when a different colour of ink is in use.
SUMMARY OF THE INVENTION
According to this invention we provide a stencil duplicator including at least one duplicator cylinder; means carried by said at least one duplicator cylinder for holding a stencil for rotation with said cylinder; a core for receiving one end of said stencil during removal of the stencil from said duplicator; duplicator cylinder drive means operatively connected to said at least one duplicator cylinder; torque limiting core holding and driving means adapted to removably support said core adjacent and parallel to said at least one cylinder and to be driven by said duplicator cylinder drive means, said core holding and driving means being constructed to rotate said core with a surface speed higher than that of said at least one duplicator cylinder but with a limiting maximum torque transmitted to said core; and means for optionally engaging drive from said duplicator cylinder to said core driving means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order that the invention may be more clearly understood, the following description is given, merely by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is an elevation of one form of stencil duplicator according to the invention; and
FIG. 2 is a view of the line II--II of FIG. 1.
FIGS. 1 and 2 show the left and right hand side frames 1, 2 of a twin cylinder duplicating machine and the upper duplicator cylinder 20 extending therebetween. A bar 3, having a D-section, is rotatably carried by and extends between the two side frames.
A cranked lever 4 is fixed to the bar 3 near the left hand side frame 1, while a second cranked lever 5 is slidable on, but rotatable with, the bar 3 near the right hand side frame 2.
At the outer end of each cranked lever 4, 5 is rotatably mounted a drive wheel 6, 7. These drive wheels are of plastics material and have peripheral grooves in which are located O-rings 8, 9 serving as tyres to engage the cylinder 20.
The drive wheels 6, 7 are in surface contact with knurled, plastics, secondary drive wheels 10, 11, respectively, freely rotatably mounted on the levers 4, 5. Coaxial with, and fixed to rotate with, the secondary drive wheels are core holding members in the form of knurled discs 13 on which is mounted a core roller in the form of a hollow cylinder 12. The core roller 12 is provided with a slot 12a for a purpose to be described below. Each secondary drive wheel 10 or 11 and its associated disc 13 may be integral. The core roller 12 obscures the left hand disc, but is shown cut away in part at its right end to show part of one of the two discs 13.
A control means for the apparatus is capable of pivoting the two levers simultaneously and includes a two-lever articulation linkage 14, 15, of which a first lever 14 is fast with the D-shaped bar 3 between the right hand lever 5 and side frame 2 for rotation with the lever 5. Between lever 5 and lever 14 is a compression spring 16 on the bar 3 urging lever 5 to the left as shown to hold the right hand core-supporting knurled disc 13 in engagement with the core roller 12.
The control means shown clearly in FIG. 2 comprises, in addition to the pivoted levers 14, 15 of the articulation linkage, a pin 17 fixed to the side frame 2 and engaging in an L slot 18 in the lever 15. A tension spring 19 connects pin 17 to lever 15, urging lever 15 to the left. Leftward movement of lever 15 would cause clockwise rotation of lever 14 and thus bar 3, bringing drive rollers 6, 7 into contact with the machine cylinder, shown at 20 in FIG. 2. Lever 15 can be retained in its position as shown in FIG. 2, however, by the pin 17 engaging in the recess formed by the shorter limb of the L slot at the left end of the slot.
In order to achieve the desired "over drive" to the core roller 12, the secondary wheel 10, 11 is smaller than the drive wheel 6, 7 and the drive wheel 6, 7 is about the same diameter as the core roller 12 so that the surface speed of the core roller 12 will be greater than the cylinder surface speed to ensure tension in the stencil or screen during removal from the cylinder, thereby providing a clean and neat removal and rolling up. A suitable ratio of core roller to cylinder surface speeds is 1 1 / 3:1, i.e. approximately 33 1 / 3% over drive to the core roller 12 in terms of union stencil speed.
When a stencil 21 spans the gap between the cylinder 20 and core roller 12 the tension maintained by the over drive will induce slippage in the drive to the core, e.g. between the cylinder 20 and the drive wheel tyres 8, 9 and it is for this reason that the material for the tyres 8, 9 of drive wheels 6, 7 will transmit a maximum frictional force to the wheels 6,7 which limits the torque applied to the core 12 to avoid rupture of the stencil 21.
The apparatus may be operated as follows to remove a stencil or the ink screen from the duplicator. Before, for example, a stencil is to be removed from the cylinder 20, a core roller 12 is placed on and between the discs by moving lever 5, carrying the drive wheels 7 and 11 and the knurled disc 13, to the right to allow positioning of the core roller 12 and releasing it again to allow the knurled disc 13 to engage the right hand end of the core roller 12. As explained above, compression spring 16 causes the core roller 12 to be firmly held.
When the stencil 21 is ready for removal, the lever 15 of the control mechanism is then simply raised relative to the pin 17 fixed to side frame 2, whereon tension spring 19 can rotate bar 3 until drive wheels 6, 7 contact cylinder 20 on either side of a stencil thereon.
The free end of the stencil is lifted manually from the cylinder, placed on the top of the core roller 12 and pressed thereagainst. The ink and moisture present will provide sufficient adherence.
Appropriate rotation in this case in the anti-clockwise sense, of the cylinder 20 will then cause the stencil to be rolled up on core roller 12, and thus removed from the cylinder. When the stencil is completely rolled up on the core roller 12 the drive wheels 6, 7 are withdrawn from the surface of cylinder 20 simply by pushing the link 15 forwardly (to the right as viewed in FIG. 2), until pin 17 engages in the recess in slot 18 to hold the link 15 with the spring 19 in tension.
At some later convenient time, for example during printing with a fresh stencil while the duplicator is automatically counting the number of copies required, the operator can at his or her leisure remove the core roller 12 simply by sliding lever 5 on bar 3 (see FIG. 1).
It is also possible for stencils themselves to form the required roller, rather than requiring a separate core roller. This can be achieved by adapting the stencil backing sheet, which is normally attached to a stencil but removed therefrom once the stencil has been placed on the duplicating machine, such that after removal from the stencil heading card the backing sheet can be rolled up to provide the roller to be fitted on the roller engaging members 13.
The embodiment particularly described above could also be used for rolling up ink screens, particularly using the slot 12a, or other attachment means (not shown), to accommodate the heading bar and springs. The apparatus could also, if it were positioned on the other side of the cylinder, i.e. the right hand side in FIG. 2, remove a stencil with the head leading, again, particularly if the slot 12a is provided to receive the head strip on the stencil.
Where the cores are of tubular form, the core engaging members could be collets, i.e. frusto-conical members instead of the discs 13 shown, and the core may if desired be mounted thereon so as to slip rotatably relative thereto.
The core may take any other practical form, for instance it could be a flat card but where, as in the above described construction it is in the form of a roller, it may be made of thin cardboard or plastics material. The core is expected to be extremely simple and cheap to make, so that a used stencil which is no longer required may be discarded with its supporting core within it, or a stencil or ink screen can be stored for a time wrapped on the core.
Similar considerations apply to removing ink screens, for instance for temporary storage while ink of a different colour and therefore a different screen is used. Again, the screen can be removed with either end leading into the slot 12a to accommodate the springs and header bar normally provided at the free end of the screen. The springs could, alternatively, be clipped to the core or whatever other means are provided for rolling the screen up. | A device for rolling up onto a core a stencil or ink screen being removed from a duplicator, in which means alongside the or a duplicator cylinder for supporting a core and for driving it at a peripheral speed in excess of the peripheral speed of the duplicator so that a stencil or ink screen from the duplicator may be unrolled from the cylinder and onto the core with tension in the stencil or ink screen maintained by virtue of slipping drive to the core. | 1 |
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/836,255 entitled “Laser Epitaxial Lift-Off of High Efficiency Solar Cell” filed on Jun. 18, 2013, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention applies to epitaxially grown solar cells and specifically to inverted solar cell structures. Inverted metamorphic III-V multi junction solar cells achieve the highest efficiencies (>30% in space and >40% terrestrial under concentrator). These cells are grown epitaxially on GaAs wafers that are up to 700 μm thick. The solar photons are absorbed in the epitaxial layer, which is about 10 μm thick. The substrate is only for mechanical support and considered wasted from a materials point of view. It is desired to lift-off the epi-layer and transfer to flexible polyimide substrate and to reuse the GaAs wafer to grow another epi-layer multiple times. The cost of materials to produce a GaAs wafer suitable for a solar cell is about $50 per Watt. This accounts for about 40% of the cost of the finished cell. There is a need to make high efficiency solar cells thin, lightweight and flexible to achieve high specific power (>200 W/Kg); and foldable so that they can be stowed in a small volume to increase payload space. A new cost-effective dry lift-off process which transfers the active cell layer wafer-scale to a less expensive flexible substrate without ion implantation or chemical etching is presented. This yields thin high efficiency solar cells which have the same performance on the host substrate as on the growth substrate and which are easily scalable to large size arrays. This process allows re-using of the base semiconductor wafer to grow new cells which results in savings in GaAs materials, grinding and etching expenses. This technology reduces the cost of the cell by 30% and allows a very rapid growth of the terrestrial market for high efficiency III-V solar cells.
[0004] The savings are not only monetary. This has huge implications on natural resources. Gallium is the rarest component of the photovoltaic compounds. All the newly developed solar cell materials, such as CIGS, contain Gallium. As the substrate must currently be ground away for the epitaxial lift-off, 12% of the world's current Ga production from mining goes to waste. This creates one of the most expensive toxic wastes because GaAs contains 48% Ga and 52% arsenic, which is toxic. Thus, cost is not the only issue but also availability of the material. Therefore, this technology solves the bottleneck in the Ga supply chain and will have broad impact on society and the ecology.
[0005] The base wafer accounts for 40% of the cost of a finished cell. Thus, reducing the materials used in solar cells will go a long way toward reducing the overall cost of the cell. This can be achieved by transferring the epi-layer to a cheaper substrate and reusing the wafer to grow another epi-layer. This would achieve the lowest cost, while preserving rare earth materials.
[0006] 2. Discussion of Related Art
[0007] Wet epitaxial lift-off (WELO) has been demonstrated by incorporating a lattice-matched sacrificial release layer, such as Al 0.7 Ga 0.3 As, under the epi-layer, which gets etched off chemically in HCl or HF [1,2,3]. It takes up to several hours to free a GaAs layer from its growth substrate due to the restricted access of the etchant to the AlGaAs layer, especially for large size wafers. This is considered too slow for industrial utilization. It should take only seconds per wafer to be viable for large scale manufacturing. Therefore, a technique for quicker peel-off that would have wider industrial application is needed.
[0008] Solar cell manufacturers prefer to grow lattice-matched structures in order to minimize slips and dislocations which can degrade the performance of the solar cell. Nevertheless, thick epi-layers can be grown on strained layers, such as In 0.3 Ga 0.7 As, if the thickness of the strained layer is kept below the critical thickness, which for 2% strain is 50 mono-layers or about 10 nm. Lattice-matched InGaP etch stop layers are grown routinely under triple junction solar cells.
[0009] There were several recent attempts in the industry by IBM [4], IMEC [5,6] and AstroWatt [7] to slice a wafer from ingot kerflessly using a technique called “spalling”. These efforts concentrated mainly on silicon. A thick metallic stressor layer, usually Ni, is deposited on the semiconductor wafer and heated at very high temperature >800° C. The stress caused by the difference in the coefficients of thermal expansion between metal and semiconductor as the wafer cools to room temperature exceeds the toughness of the material and causes a crack to propagate in the substrate parallel to the surface at a certain depth below the interface. This causes a thin layer to separate from the base substrate and remain stuck to the metal film. A high peak temperature is necessary to cause the stresses. This enhances the diffusion of impurities from the metal into the silicon which act as recombination centers for electron-hole pairs and lower the efficiency [5,6]. Further, the high temperature affects the morphology of the crystal which causes the crack to propagate uncontrollably. As a result, the depth at which the cleavage occurs cannot be controlled precisely and the surface is rough. The metal layer is dissolved which yields a 25 μm free standing silicon foil. A solar cell is subsequently fabricated in the silicon foil. Foils up to 150 cm 2 area have been fabricated [7]. The extracted foil is not supported and is therefore brittle and prone to chipping. Nevertheless, single junction solar cells fabricated in the foil exhibited similar performance to identical cells on bulk substrates which indicates that the quality of the crystal is not compromised by the lift-off. The highest efficiency that has been demonstrated on these foils is 15% [7].
[0010] The (110) is the preferred cleavage plane in GaAs. However, solar cell manufacturers are reluctant to grow on (110) wafers because most of the industry is built on (100) wafers, albeit with large off-cut angles up to 15° toward the (111)A plane.
[0011] The ultimate goal of all lift-off techniques is to re-use the base wafer after lift-off.
[0012] Laser micromachining inside the bulk of materials is not new. It is used for making waveguides inside transparent materials (glass) [10], and has been proposed as a way for wafering silicon from ingot [11]. These techniques depend on non-linear absorption at the focal point, forming a sub-surface defect while leaving the region between the surface and the defect untouched. Light from an IR laser at a wavelength above 1 μm is focused below the surface and scanned across the wafer. The size of the defect depends on the depth of focus. This requires the use of large diffraction limited lenses with short focal lens and low f# and necessitates the use of high precision and resolution vertical positioning stages, which are expensive. Silicon does not benefit from heterogeneous epitaxial growth where separation of the epi-layer from the wafer can be done using a sacrificial layer at the interface, and therefore, wafering in silicon relies more on the quality and precision of the optics rather than the physics of absorption.
[0013] The crystallographic structure of Si has been damaged by radiation in the NIR at 2256 nm with a threshold fluence of 0.18 J/cm 2 using sub-picosecond pulses [12]. This radiation should also damage Ge because it has weaker covalent bonds having a lower bandgap. Laser ablation is also used for epitaxial lift-off of GaN layers from sapphire substrates for the fabrication of LEDs [13].
[0014] It is desired to cleave at or very near the epi/wafer interface without sacrificing substrate material. That would be true epitaxial lift-off so that the original wafer is recovered at full thickness. III-V materials have the advantage that devices are fabricated in epitaxially-grown layers. Thus, the epi-layer can be peeled off the substrate and transferred to a flexible carrier and the substrate can be reused to grow another epi-layer. The fragile crystalline solar cell must be supported at all times. A suitable flexible carrier is polyimide Kapton® sheet which is backed by DuPont and qualified for space applications. Kapton is available in sheets as thin as 50 μm which are easy to handle and come pre-coated with a uniform layer of acrylic adhesive. It operates continuously from cryogenic to >200° C. which is suitable for space applications. A Kapton sheet with adhesive layer is bonded to the epi-side of GaAs wafer using a hot roll laminator and then cured in an oven at 150° C.-190° C. for about an hour. After lift-off the thin epi-layer is carried by the Kapton sheet which serves as permanent carrier of the IMM solar cell. The entire thickness of the thin solar cell is less than 100 μm, which meets the specific power requirements for space.
[0015] FIG. 1 shows a thin IMM3J epi-layer carried by polyimide substrate. It shows a smooth shiny surface of the InGaP etch stop layer. This can be obtained by lifting-off the epi-layer without sacrificing the growth wafer so that it can be re-used to grow another epi-layer. This solar cell was rolled mechanically to a radius <½″ and shocked thermally without fracturing.
[0016] There are two ways to separate the epi-layer from the growth substrate kerflessly: either by 1) driving a crack at the interface due to thermal stresses, or 2) disintegrating a sacrificial layer by laser ablation. These two approaches involve different physics but lead to the same end result. Both are dry, meaning they are fast and there is no wet etching. These two concepts are illustrated in FIGS. 2 a and 2 b , respectively.
Dry Epitaxial Lift-Off (DELO)
[0017] The polyimide serves not only as the permanent carrier of the thin crystalline solar cell but also creates the thermal stresses that lead to cleavage. Kapton has a CTE of 18-20 ppm/° C. compared to 5-6 ppm/° C. for GaAs. The temperature is lowered by introducing the composite structure slowly in liquid nitrogen at −196° C. Within a minute, an audible crack initiates and the film snaps right off. A temperature differential ΔT˜300° C. (between the curing temperature and LN 2 ) and a CTE difference of 12-14 ppm/° C. cause a stress of about 20 MPA which is sufficient to initiate a crack because it is amplified at the crack tip. Crack nucleation is due solely to the build-up of thermal stresses without applying external mechanical force. The crack propagates across the wafer in a fraction of a second. The wafer cleaves spontaneously at a plane parallel to the bond interface. For GaAs the lift-off temperature is about −140° C. whereas for Si the wafer must be cooled down to −196° C. The lift-off happens in a split-second and was captured on video. The front side of the solar cell can be processed on the Kapton after lift-off. The concept applies to all semiconductor materials, Si, Ge, GaAs and InP, and to all epitaxially grown solar cells for space as well as terrestrial applications. The concept is illustrated in FIG. 3 .
[0018] The sequence of frames in FIG. 4 taken from http://www.youtube.com/watch?v=B1tj5ZUe9TI show the backside of a GaAs wafer piece bonded to Kapton 50 μm thick on the front side (underneath), on a plate as it is lowered slowly in a dewar of liquid nitrogen. The successive pictures show the drop in temperature over the course of a few minutes until lift-off happened at a temperature of −140° C. As the lift-off temperature was reached the Kapton layer snapped off almost instantaneously. The curled peeled off epi-layer stuck to the Kapton sheet (brown) is shown in FIG. 4 d sitting on top of the GaAs wafer piece.
[0019] The first two video clips show the rolling and unrolling of thin GaAs epitaxial layers on Kapton as it is thermally cycled between a hot plate at +100° C. and −196° C. The third video shows the lift-off wafer scale. The last video shows the lifted-off layer held on a standard vacuum chuck spinning at 3000 RPM which allows fabrication of the front side of the solar cell. These movies take less than a minute each:
http://www.youtube.com/watch?v=WED8cj2YfIw 1:33 min rolling and unrolling http://www.youtube.com/watch?v=U5rxiwkenmI 1:00 min rolling and unrolling http://www.youtube.com/watch?v=BJr1LDdZabg 0:48 min wafer scale lift-off happens at 40 seconds http://www.youtube.com/watch?v=VC6v7_RAOok 0:09 min GaAs on Kapton spinning at 3000 RPM
[0024] The polyimide is very advantageous because it is able to induce lift-off for a temperature drop ΔT of only 300° C. compared to metal which requires raising to >800° C. Furthermore, it is completely inert and does not contaminate the semiconductor layer. This process is low temperature between +200° C. and −196° C. The combination of polyimide/adhesive is tough and can withstand these temperatures. The acrylic adhesive holds in liquid nitrogen and is able to transmit the force and break-off a layer of semiconductor wafer without losing its grip. The adhesive layer is applied uniformly to Kapton. It has a smooth surface and supports the epi-layer over the entire 4″ wafer.
Cleavage by Crack Propagation Due to Thermal Stresses
[0025] The following is a summary of results obtained:
1) lifted-off a layer of GaAs 10-15 μm thick equivalent to IMM3J layer thickness, 2) cleaved 2″ (110) and 4″ (100) orientation wafers and saved the base wafer as one piece, 3) reused a base wafer and lifted-off another layer several times, there did not appear to be a limit to the number of reuses as long as the substrate remained thick enough, 4) obtained atomically smooth (mirror-like) surfaces (single atomic plane cleavage, roughness <1 nm) over areas (>1 cm 2 ) in (110) orientation wafer, 5) fabricated front side of solar cell on Kapton and demonstrated that the performance is not degraded compared to identical solar cell on GaAs wafer.
FIGS. 5 and 6 show the lifted-off layer on Kapton to the right and the base wafer to the left for GaAs (110) and (100), respectively. Uniform cleavage is obtained across 4″ wafer. The (110) orientation yields smoother cleaved surface as expected. FIG. 7 shows AFM average roughness of 0.059 nm, below instrument noise, indicating that the cleavage is a single atomic plane.
[0031] A GaAs wafer bonded to polyimide substrate bends significantly in LN 2 at −196° C. due to thermal stresses. Even at room temperature, there is significant residual stress and bow, as shown in FIG. 8 . The thickness of the polyimide is optimized to deliver the maximum bending stresses. The highest stresses are obtained in the bending mode. The thin layer on Kapton rolls down to 0.75-inch diameter in LN 2 without cracking, as shown in FIGS. 9 and 10 . As the temperature drops, the polyimide shrinks at a higher rate than the GaAs. This causes the composite structure to bend and roll as a tube with the polyimide on the inside. The thin solar cell flattens when placed on a hot plate at 100° C.
[0032] The success of the epitaxial lift-off by crack propagation hinges on a delicate balance between the initial scratching and the loading by the polyimide which depends on the polyimide-to-GaAs thickness ratio and the crystallographic orientation of the wafer. GaAs (110) cleaves smoother and more uniformly than (100). The extent of the lateral crack propagation also depends on the thickness ratio. Thicker polyimide causes the crack to propagate farther but lifts-off a thicker layer and may break the wafer. It is desired to minimize the thickness of polyimide to increase the specific power ratio for space applications. The right combination of stresses is necessary to guide the crack near the interface. However, thermal stresses cause significant bow as illustrated in FIG. 2 a . It is desired to minimize the effect of stresses on the performance of the solar cell.
[0033] Precise control over crack propagation is necessary to lift-off layers with uniform thickness and smooth surface. Atomically smooth cleaved surfaces were obtained by controlling the crack propagation. The polyimide applies pure bending moment on the GaAs wafer which is the optimal mode of opening a crack in tension (Mode I) because it avoids the shearing stresses (Mode III) which cause deviation in the path and uncontrollable crack propagation [8,9]. If these requirements are not met then the crack can bifurcate and branch out and cause secondary cracks to propagate at different angles along different paths. To maximize yield in production a fundamental understanding of fracture mechanics at the nano-scale is essential. For industrial applications this process must be controlled. The focus of the research is to better understand the stress mechanisms that lead to rupture and how to control the path of the crack. The challenges are controlling the crack propagation depth near the epi/wafer interface and preventing the substrate from shattering. Femtosecond laser ablation produces less severe stresses and a gentler lift-off than cooling in liquid nitrogen. Both concepts lead to recovery and reuse of the growth substrate.
SUMMARY OF THE INVENTION
[0034] A sacrificial layer embedded between the GaAs wafer and the multi junction solar cell is damaged gently with a laser at the appropriate wavelength and fluence to break the bonds at a certain plane without causing excessive heat or stresses to avoid damaging the substrate or the solar cell. The sacrificial layer must be single crystal and grown epitaxially. It is preferred to use a layer that is lattice-matched to the substrate in order to minimize the defects and avoid dislocations in the subsequently grown triple junction solar cell. It must have a bandgap lower than that of GaAs so that the laser radiation is not absorbed in the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The accompanying drawings are not intended to be drawn to scale. In the drawings:
[0036] FIG. 1 Thin IMM3J solar cell on polyimide substrate 50 μm thick;
[0037] FIG. 2 a Concept 1 Crack propagation due to thermal stresses;
[0038] FIG. 2 b Concept 2 Laser ablation of embedded epitaxial release layer;
[0039] FIG. 3 a Semiconductor wafer with epi-layer bonded to Kapton® permanent carrier 50 μm thick;
[0040] FIG. 3 b Semiconductor wafer separated and solar cell carried by Kapton® after lift-off;
[0041] FIG. 4 Epitaxial layer lifted-off GaAs wafer piece at −140° C. on Kapton sheet (brown) 50 μm thick;
[0042] FIG. 5 GaAs (110) wafer lifted on Kapton (right), base wafer (left);
[0043] FIG. 6 GaAs (100) wafer lifted on Kapton (right), base wafer (left);
[0044] FIG. 7 AFM roughness measurements;
[0045] FIG. 8 GaAs wafer bonded to polyimide bowed at room temp;
[0046] FIG. 9 GaAs epi-layer curled to 1-inch diameter;
[0047] FIG. 10 GaAs epi-layer rolled to 0.75-inch diameter;
[0048] FIG. 11 Absorption coefficients of Ge and GaAs;
[0049] FIG. 12 Structure consisting of GaAs wafer, SiGe sacrificial layer, triple junction solar cell, Kapton/adhesive;
[0050] FIG. 13 Non-inverted triple junction solar cell where the Si/Ge layer acts as bottom cell;
[0051] FIG. 14 Inverted metamorphic triple junction (IMM3J) solar cell consisting of InGaP top junction grown first on SiGe sacrificial layer, GaAs middle junction, and InGaAs bottom junction (lattice mismatched) grown last;
[0052] FIG. 15 Lattice matched inverted triple junction (LMI3J) solar cell consisting of InGaP top junction grown first on SiGe sacrificial layer, GaAs middle junction, and SiGe bottom junction grown last;
[0053] FIG. 16 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at 800 nm [15];
[0054] FIG. 17 a Direct and indirect bandgaps in Ge;
[0055] FIG. 17 b Direct and indirect bandgaps in Ge and GaAs;
[0056] FIG. 18 a Temperature profile for 38 ns pulse;
[0057] FIG. 18 b Temperature profile for 38 fs pulse;
[0058] FIG. 19 Heat affected zone for CW, nanosecond and femtosecond pulsed lasers, courtesy of Raydiance, Inc.;
[0059] FIG. 20 a GaAs wafer piece broken by ns laser at 1.064 μm;
[0060] FIG. 20 b Ge wafer piece melted with ns laser at 1.064 μm shows cracks;
[0061] FIG. 20 c Ge wafer piece melted with ns laser at 1.064 μm;
[0062] FIG. 21 Band gap of GaAs, one photon and two-photon Absorptions are shown by single and double vertical arrows [17];
[0063] FIG. 22 Two-Photon Absorption coefficients at 300 K and 77 K for GaAs and In 0.36 Ga 0.64 As [17];
[0064] FIG. 23 a Direct two photon absorption in Ge [18];
[0065] FIG. 23 b Indirect two photon absorption in Ge [18];
[0066] FIG. 24 Single and Two-Photon Absorptions in Ge [30];
[0067] FIG. 25 Specs of TOPAS Prime® OPA when pumped by 100 fs, 1 mJ Spitfire Ace® regenerative amplifier;
[0068] FIG. 26 4″ GaAs wafer diced yields two cells for space applications. Several cells are integrated on common blanket polyimide sheet. Photo courtesy of Sharp Corporation;
[0069] FIG. 27 illustrates schematically packaged and encapsulated 8-layer solar cell;
[0070] FIG. 28 Two cells integrated on copper-cladded polyimide sheet with ECA (white);
[0071] FIG. 29 a Contacting both sides of IMM cell from the top of the wafer;
[0072] FIG. 29 b Interconnecting of several IMM cells in series;
[0073] FIG. 30 a Deformations of solar cell structure of FIG. 27 at −200° C. for Spray-on Polyimide Thickness of 25 μm, at different CTE's, flat at CTE=16.5 ppm/° C.;
[0074] FIG. 30 b Deformations of solar cell structure of FIG. 27 at −200° C. for Spray-on Polyimide Thickness of 50 μm, at different CTE's, flat at CTE=20 ppm/° C.;
[0075] FIG. 31 Top view of the interconnect region between two adjacent cells;
[0076] FIG. 32 Process for electroplating series and parallel connections;
[0077] FIG. 33 Structure of solar cell with the absorption layer removed from surface of GaAs wafer;
[0078] FIG. 34 Structure of solar cell with GaAs buffer layers and InGaP protection layers.
DETAILED DESCRIPTION OF THE INVENTION
[0079] This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing”, “involving”, “triple-junction” or “multi-junction” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
Laser Epitaxial Lift-Off (LELO)
[0080] The focus of the instant invention is on the laser concept illustrated in FIG. 2 b.
[0081] Ge and GaAs are two well known semiconductor materials which have a peculiar relationship. They are almost lattice matched (Ge slightly larger) but Ge has an indirect bandgap (0.67 eV) well below that of GaAs (1.42 eV). Si is another well known semiconductor material which has a lattice constant smaller than both. They all share the same face centered cubic (FCC) diamond structure. The inclusion of 2% silicon in germanium pulls it slightly to the left and aligns it perfectly with GaAs. Therefore, the sacrificial layer is Si 0.02 Ge 0.98 . InGaAs is another potential material. The inclusion of Indium in GaAs increases the lattice unit dimension, with the result that the InGaAs layer will be strained. A pseudomorphic InGaAs layer up to a few nanometers thick can be grown and will maintain its strain, but InGaAs has a bandgap and a melting point (1150° C.) higher than Ge (937° C.), and therefore presents no advantage over Ge. Furthermore, a strained layer this thin is not effective at guiding a crack. By contrast a SiGe layer can be grown to any thickness because it is lattice-matched to the GaAs substrate.
[0082] The embedded SiGe layer is ablated using a laser in the NIR. This exploits the difference in absorption between Ge and GaAs due to the fact that they have substantially different bandgaps. Therefore, the choice of wavelength is of paramount importance.
[0083] A laser with the right combination of threshold of energy and pulse duration is used to damage, i.e. photo-chemically break the bonds and weaken the SiGe layer so that the epi-layer can be separated from the wafer gently without causing excessive stress or bow, by pulling off the Kapton with either mechanical force or vacuum. This is true epitaxial lift-off because it guarantees that the separation is at the interface. True ELO should not depend on the wafer-to-polyimide thickness ratio or the orientation of the wafer. Any film can be transferred from any semiconductor wafer to a flexible substrate regardless of the thickness or orientation if a suitable wavelength is used that is not absorbed in the wafer but absorbed in the sacrificial layer. This relies on the physics of absorption rather than thermal stresses due to CTE mismatch. Nevertheless, the heat of ablation may cause a crack to propagate in the Ge layer [14]. Most importantly, it relaxes the requirement on the optical focusing system. The lift-off can therefore be done using relatively inexpensive optical components and micro-positioning stages and mildly focused or even expanded laser beams. The embedded sacrificial layer does not even have to be within the focal zone.
[0084] Epitaxial growth of III-V compounds offers the possibility of separating the epi-layer from the growth wafer by embedding a lattice matched sacrificial layer with lower bandgap at the interface which absorbs IR radiation but which is transmitted by the substrate and the active solar cell layers. Laser ablation is usually done in the UV because most materials absorb in the UV and UV radiation is very intense. However, Ge and GaAs have been ablated with femtosecond pulses at 800 nm [15,16] and in the IR up to 5 μm [17,18,19] and with nanosecond pulses at 1.064 μm [20] separately at an exposed surface. But the buried interface between Ge and GaAs has not been damaged or ablated before.
[0085] FIG. 11 shows the absorption spectra of Ge and GaAs up to 2 μm. The absorption in GaAs drops precipitously just before 1 μm. At that wavelength there are four orders of magnitude difference between the absorption coefficients of Ge and GaAs. Thus, it should be easy task, in principle, to choose a wavelength just above 1 μm, such as 1.064 μm Nd:YAG, which is a common industrial laser with pulse widths between 20 and 200 nanoseconds should do the job, but it doesn't. It is not so simple because this graph is for single photon absorption. The absorption in Ge and GaAs is actually due to two or even three photons.
[0086] FIG. 12 shows the solar cell structure bonded to Kapton/adhesive. The SiGe sacrificial layer, which is predominantly made of germanium (2% Si) and referred to as the Ge layer, can have any thickness. The Ge layer can be 5 μm thick and can be as thick as 20 μm to shield the solar cell from the heat of ablation. The Kapton/adhesive is bonded to the epi-layer face down. The laser is incident from the bottom side in FIG. 12 through the GaAs wafer. The challenge is to absorb in the Ge layer without damaging the GaAs wafer. The incident light can be absorbed in GaAs as long as it does not heat the GaAs wafer above 450° C. [21]. A very thin layer about 100 nm of the Ge (blue in FIG. 12 ) adjacent the GaAs is ablated.
[0087] A non-inverted triple junction solar cell structure, where the SiGe acts as the bottom junction is shown in FIG. 13 [32]. By contrast, in an inverted IMM3J structure the InGaP top junction is grown first on the SiGe layer and the middle GaAs junction next, i.e. the order of growth of GaAs and InGaP is reversed, as shown in FIG. 14 . A metamorphic (lattice mismatched) InGaAs bottom junction is grown last. In an inverted cell the SiGe layer does not play any role in the cell, other than a sacrificial layer, which gets ablated away. The red arrow in FIG. 13 points to the plane of separation. After separation, the remaining SiGe on the solar cell, which is now on Kapton, is etched away. Alternatively, a second SiGe layer is grown last on the GaAs layer, which provides the bottom junction, as shown in FIG. 15 . This yields an all lattice-matched inverted (LMI) solar cell.
[0088] The main objective is the ablation of an embedded layer. The problem is that the laser has to cross the GaAs wafer without damaging it. And the absorption should not be the result of precise focusing on the Ge. The focus can be vertically anywhere (outside the GaAs wafer). It is only the Ge that should absorb, not the GaAs. This is achieved through proper choice of the wavelength, pulse duration and laser power. In fact it is desired to spread the laser over an entire 4″ wafer, as long as the laser has enough power to do the ablation. The Ge evaporates when ablated and needs room to escape. It would be more advantageous to ablate the entire wafer in one shot, if possible, to provide room for the Ge to escape. Materials melt before evaporating. Ge melts at 937° C. whereas GaAs melts at 1240° C. So it is expected that Ge would melt first. Yet GaAs has a lower threshold for melting and ablation than Ge when illuminated with 100-500 femtosecond pulses at 800 nm [15], as shown in FIG. 16 , which suggests that there are other mechanisms of absorption.
[0089] The threshold of ablation of Ge is about 400 mJ/cm 2 . It should be increased by 56.25% to account for the reflection at the GaAs/air interface (n=4). A good estimate of the fluence needed for ablation is 500 mJ/cm 2 . Actually the material may not need to be melted or ablated. It needs only to be weakened. Even though GaAs has a wider bandgap of 1.42 eV (0.87 μm), but it actually has a lower threshold than Ge. This shows that it is a better absorber. It must be due to the direct bandgap. However, Ge too has a direct bandgap at 0.8 eV (1.55 μm) which absorbs even more than the indirect gap at 0.664 eV corresponding to a wavelength of 1.867 μm for single photon absorption. Both have tendencies to absorb non-linearly in their direct bandgaps. Thus, one problem to be faced is that GaAs is a better absorber and has a lower threshold than Ge. The E-k diagrams of Ge and GaAs are shown in FIGS. 17 a and 17 b.
[0090] Even though GaAs has a melting temperature of 1240° C. but it cannot take more than 450° C. [21]. Processing GaAs at temperatures above 450° C. requires As-rich atmosphere, which is toxic. Furthermore, the temperature in the entire structure should be limited to 200° C. due to the organic adhesive and Kapton. Impurities in the GaAs accelerate the absorption. The lattice and CTE of Ge and GaAs are well matched, however, raising the temperature beyond 200° C. would create stresses. The structure cannot be heated with a steady source like a CW laser. Even nanosecond pulses are too long and lead to heating of the entire structure beyond the damage temperature of GaAs.
[0091] The Ge reaches a temperature well above 937° C. It melts, evaporates and may even turn into plasma. The heating must be localized to the Ge layer. The heat affected zone (HAZ) should not spread beyond the optical absorption depth. The goal is to break the covalent bonds in Ge without raising the temperature in GaAs and the surrounding materials beyond 200° C. Ideally, the surface of GaAs remains intact. However, even though the GaAs wafer may be transmissive to the laser, the plume from the confined ablated Ge layer may create an explosive pressure zone leading to the removal of some GaAs as well.
Ultra-Short Pulse Laser Ablation
[0092] Ablation is inherently a thermal process at the nano-scale. The material turns to vapor as it absorbs the intense pulse energy. The absorption depth is on the order of 100 nm. The issue is whether the heat has enough time to diffuse beyond the absorption zone before the pulse has ended. The diffusion length varies as the square-root of the thermal diffusivity times pulse duration. For nano-second pulses it is on the order of 1 μm; for femtosecond pulses 1 nm. Damage to the structure occurs when the heat spreads outside of the ablation zone. In this case the GaAs should remain intact. Thus, the heat must remain localized inside the Ge. In order to control the ablation it is important to contain the heat inside the absorption zone.
[0093] FIGS. 18 a and 18 b show a simulation of the temperature profile at the Ge/GaAs interface for two pulse widths of 38 ns and 38 fs, respectively, using COMSOL for a Ge temperature of 937° C. corresponding to the melting point. The rectangle at the center left has dimensions of 500×100 nm and represents the absorption zone. The color coded scale to the right shows the temperature from ambient 293 K (blue) to 473 K=200° C. (red). It is seen that for nanosec pulses about 1 μm radius inside the GaAs wafer is above 200° C. In fact the temperature reaches above 900° C., whereas for femtosecond pulses the temperature across most of the wafer remains cool near room temperature well below 200° C. The heat is confined to the 100 nm absorption zone.
[0094] There are hundreds, possibly thousands of papers on the subject of laser ablation and specifically ultra-short pulse laser ablation. In almost every instance the authors state that the fundamental mechanism of ablation is still not understood [22,23]. However, it is generally agreed that there are two regimes: the long pulse regime which extends from nanosecond all the way to CW, and the ultra-short pulse regime, below picosecond down to 100 femtoseconds. For this reason, ablation is often described as being either thermal (for long pulses) or non-thermal (for ultra-short pulses) on a micro-scale. The heat is confined to the nano-scale. It is also known as “cold ablation”. The goal of the instant invention is to engineer a way for the radiation to be absorbed in Ge after passing through GaAs, by choosing the appropriate wavelength, power level and pulse width.
[0095] Incoming photons are absorbed by the free electrons leading to the formation of a gas of hot carriers which transfer their energy to the ions through the emission of phonons. Ions and electrons eventually reach equilibrium on a timescale 10 −12 -10 −11 s (1-10 picoseconds). This timescale is crucially important as it sets the boundary between strictly thermal and non-thermal regimes, which distinguishes “long” from “short” pulses. A nanosecond is a very long time by electronic scales. If the pulse width is much larger than the diffusion time, equilibrium prevails and phase changes can be considered as slow thermal processes involving quasi-equilibrium thermodynamics. In contrast, for ultra-short pulses (<10 −12 s), the material is driven into a highly non-equilibrium state [22]. In this case, each pulse acts as if it were alone, independent of the other pulses. By contrast, in the long pulse regime the material reaches a steady state temperature under the cumulative bombardment of many (tens of thousands) of pulses and the surrounding material is heated beyond the melting point. For this reason, a femtosecond laser is used to ablate the embedded Ge layer because it produces a cleaner colder cut.
[0096] Heat diffusion reduces the efficiency of the micromachining process because it sucks energy away from the work spot, energy that would otherwise be used for removing material. Heat diffusion reduces the working temperature at the focal spot, pinning it not much higher than the melting temperature. It creates shock waves and microcracks in the surrounding material. The HAZ is about 30 μm wide. It causes damage to adjacent structures, delamination, and poor shot-to-shot reproducibility. The melted material resolidifies and redeposits and contaminates the surface. The debris is extremely hot and very difficult to remove. It is therefore desirable to reduce or eliminate heat diffusion.
[0097] Ultrafast pulses are extremely short and powerful. The laser energy has nowhere to go or more precisely does not have the time to move away. The energy piles up in the absorption zone, whose temperature rises instantly past the melting, boiling and evaporation points. So much energy is deposited in such a short time that the material is forced into a state of plasma. Femtosecond lasers deliver a huge amount of peak power up to a hundred GigaWatt. The power density reaches several TeraWatt/cm 2 on the work surface. No material can withstand these power densities. Even air molecules breakdown. There is no melt phase. The energy is absorbed by the electrons much faster than it is transferred to the lattice. Heat diffusion is virtually eliminated [25]. There is no collateral damage, no melt zone, no micro-cracks, no shock waves, no recast layer, and no damage to adjacent structures. The plasma expands away from the surface as a highly energetic plume taking all the heat away with it. Consequently very little heat is left behind to damage the material. This yields high quality machining, which is very desirable.
[0098] FIG. 19 illustrates schematically the difference between long and short pulse-material interactions for three different types of lasers: CW, nanosecond and femtosecond [26]. The black area indicates the size of the heat-affected zone and the blue lines show the shock waves created by the laser pulses. The CW laser (far left) removes material primarily by melting, which creates a large HAZ. The nano-second laser (center) creates a smaller HAZ, while the femtosecond laser (right) removes material by plasma plume. No HAZ is created.
[0099] Ultra-fast laser pulses have sufficient peak power and generate high enough electric fields to break the molecular bonds of the material, transforming it directly from a solid to a gas. These pulses are so fast that the energy doesn't have a chance to do more than break the material's molecular bonds. This is known as photochemical or photolytic decomposition, which usually happens in the UV. However, it can also happen in the NIR through two-photon absorption [28]. During purely photochemical processing, the temperature of the system remains relatively unchanged. It has been shown that crystalline Ge and GaAs undergo non-thermal ablation in the sub-picosecond time scale [16]. The damage is done with one pulse.
[0100] The energy is initially stored in the electronic system. If the intensity of the laser is high enough to overcome the binding energy of the outer valence electrons, then the electrons are stripped from the lattice by multi-photon absorption [27], which leads to avalanche ionization [28]. The ablation depends on the presence of free electrons in the beam path. Semiconductors have plenty of electrons, except that the vast majority of them are bound. Very high energetic radiation, such as UV or ultra-short pulse NIR lasers have enough power to knock some electrons free. The free electrons collide with other bound electrons and create an avalanche. This leaves the atoms near the surface ionized, all positively charged. The excited electrons escape from the bulk material and form a strong electric field that pulls out the ions within the impacted area. The Coulombic repulsion of the positive ions breaks the chemical bonds that previously held the solid together. The ions break apart in a cloud of rapidly expanding plasma. This process is known as Coulomb explosion, which is considered “gentle ablation” because it happens just above the threshold fluence of ablation and leaves behind an atomically smooth surface [28]. The release of fast ions with a narrow velocity distribution indicates a non-thermal process.
[0101] A power density of 5×10 12 W/cm 2 which is readily attainable with commercial femtosecond lasers, about 100 fs long pulses, when focused to an area 100 μm×100 μm=10 4 cm 2 , is close to the threshold of laser-induced air breakdown of 10 13 W/cm 2 at which plasma is generated. This yields an energy density of 500 mJ/cm 2 , which is near the threshold of ablation of Ge. Therefore, the power available from commercial lasers yields gentle ablation because it is near the threshold of ablation. At these intensities non-linear absorption becomes dominant and causes multi-photon ionization.
[0102] Ultrafast lasers are used to machine inside the bulk of transparent materials [10]. Very localized non-linear absorption occurs only at the peak of the focused Gaussian beam where the intensity exceeds the threshold. With longer pulse lasers the sample damages before the intensity reaches the threshold for non-linear absorption. For this reason, femtosecond lasers are used in selective machining of multi-layer devices, and would be useful for weakening the embedded Ge layer in the instant invention.
[0103] There is not much published data on the threshold of ablation of Ge in the NIR for femtosecond pulses, albeit at 800 nm. FIG. 16 , [15] shows that the threshold of Ge remains constant for sub-picosecond pulses at about 400 mJ/cm 2 , whereas that of GaAs decreases to 150 mJ/cm 2 at a pulse width of 100 fs. Furthermore, it has been reported in [29] that the threshold continuously decreases with a gradual transition from the long pulse, thermally dominated regime to the ultrashort pulse ablative regime dominated by impact and multiphoton ionization, and plasma formation. The strong non-linear dependence of multiphoton rates on intensity causes the threshold to become increasingly sharply defined for shorter pulse durations. The threshold of ablation of Ge in the NIR is to be measured.
Example 1
Ablation of Ge and GaAs with Nanosecond Laser at 1.064 μm
[0104] A Q-switched Nd:YAG laser with pulse width 120-250 ns, peak power 5-8 kW, energy 1-1.25 mJ per pulse, pulse repetition rate 30-50 kHz, average power 38-50 Watts, with a beam diameter of 1.2 mm was used to damage Ge and GaAs wafer pieces. The energy density on the work piece was adjusted by varying the scanning speed between 15 and 300 cm/sec and defocusing the laser beam. A bare Ge wafer piece was first melted. The results are shown in FIG. 20 . At high fluence near focus ( FIG. 20 b ) the surface became rough and cracks developed. At lower fluence ( FIG. 20 c ) the defocused laser left soft marks on the Ge, which indicates that the surface was damaged. The transmission through the double-side polished GaAs wafer was measured about 50%. However, when the laser spot was left in the same position for about 15-20 seconds it burned a hole in the GaAs wafer ( FIG. 20 a ). Ge has a higher single-photon absorption than GaAs at this wavelength (1.064 μm), as expected. But the problem is that GaAs absorbs due to two-photon absorption. For this reason a femtosecond laser would be beneficial. It is also important to use high quality GaAs wafers that are free of defects. The primary goal of the instant invention is the absorption in Ge, but since the light must pass through GaAs first, then it is necessary to study the absorption in GaAs in order to avoid it.
Choice of Wavelength
[0105] Two-photon absorption in GaAs has been studied at selected wavelengths between 1 and 2 μm [17]. The free-carrier absorption is predominantly due to holes. FIG. 21 shows possible intra-sub-band single photon absorptions (single arrows) and inter-band valence-to-conduction (double arrows) two-photon absorptions for wavelengths below the direct bandgap. FIG. 22 shows two-photon absorption vs wavelength for GaAs and InGaAs. Single photon absorption becomes insignificant above 1 μm, while two-photon absorption in GaAs vanishes above 1.75 μm. Thus, any wavelength above 1.75 μm will transmit through GaAs and can be used. However, it remains to be seen whether Ge would absorb at a wavelength longer than 1.75 μm. InGaAs has the two-photon absorption cross-section β between 30 and 36 cm/GW in the range 1.75 μm-2.3 μm, and drops to 20 cm/GW at 2.5 μm.
[0106] Two-photon absorption in Ge is both direct and indirect [18]. The direct transition is even stronger than the indirect transition, as shown in FIG. 23 . Direct two-photon absorption peaks at 0.45 eV (2.75 μm) β=28 cm/GW, while indirect two-photon absorption peaks at 0.49 eV (2.5 μm) β=0.4 cm/GW. Thus, the direct transition is much stronger than the indirect transition. Ge is an indirect bandgap material for single photon absorption. Not only does the non-linear absorption become stronger than the linear absorption, but also the direct transition becomes stronger than the indirect transition.
[0107] A much stronger transition occurs in Ge in the direct bandgap (0.8 eV) than in the thermodynamic indirect band gap (0.63 eV). Both transitions can be seen as absorption edges in FIG. 24 [30]. At the threshold fluence of ablation in Ge 400 mJ/cm 2 , the intensity I=5×10 12 W/cm 2 and the energy=50 μJoule/pulse in a 100 fs pulse. The two-photon absorption coefficient at 0.45 eV, βI=1×10 5 cm −1 , so the absorption depth=100 nm. Thus, the optimal wavelength to maximize absorption in Ge is 2.75 μm (0.45 eV), which clears GaAs. InGaAs has a slightly higher absorption coefficient in a shorter wavelength range 1.75 μm-2.3 μm. But Ge is preferred because it is lattice matched to GaAs.
Example 2
Commercially Available Femtosecond Lasers at 2.75 μm
[0108] Both Coherent and Spectra Physics make laser sources that are suitable for this application. The Spitfire Ace® regenerative amplifier emits up to 10 mJ/pulse @ 1 KHz which pumps the TOPAS Prime® optical parametric amplifier (OPA), which gives 50 μJoule/pulse per 1 mJ input at 2.75 μm. A typical energy output spectrum of the TOPAS Prime® laser when pumped by 100 fs, 1 mJ Spitfire Ace® regenerative amplifier, is shown in FIG. 25 . Thus, the OPA is capable of emitting 500 μJoules per pulse, which allows spreading the beam to an area 300 μm×300 μm on the work surface.
[0109] GaAs absorbs two photons up to a wavelength of 1.75 μm, and three photons up to a wavelength of 2.6 μm (see FIG. 3 on page 670 of [33]). Ge begins to absorb two photons at a wavelength below 3.1 μm and reaches a significant cross-section below 2.9 μm. Therefore, the preferred wavelength range is between 2.6 and 2.9 μm.
[0110] It is desired to distance the laser-damaged sacrificial layer from the interface with the surface of the GaAs wafer in order to avoid or lessen the damage to the GaAs substrate. FIG. 33 shows the laser-ablated layer (Quantum Well) having the lowest bandgap in the structure in the middle of the SiGe layer, which is removed for example about 10 μm from either the GaAs wafer surface or the solar cell. However, as the only known material with the lowest bandgap that can be grown epitaxially on GaAs is Ge, which is not significantly different from Si 0.02 Ge 0.98 , it is expected that the laser absorption would still occur in the immediate vicinity of the GaAs/SiGe interface. For this reason, it is preferred to replace the bulk of the sacrificial SiGe layer with a GaAs buffer layer, which is for example about 20 μm thick and to confine the SiGe absorption layer to the central region, as shown in FIG. 34 . A suitable SiGe layer thickness is 1-2 μm. The incorporation of InGaP protection layers on both sides of the GaAs buffer layer offers the best protection to the GaAs substrate and the solar cell. The details of the InGaP protection layers are shown in the inset of FIG. 34 . The InGaP protection layer can suitably be made of a GaAs layer sandwiched between two In 0.49 Ga 0.51 P layers, for example about 0.1 μm each, as taught by [34].
Integration and Packaging of III-V Solar Cells
[0111] A GaAs wafer with IMM3J epi-layer capped with a metal layer is bonded face down to Kapton substrate and trimmed. After lift-off a typical 4″ wafer is diced to yield two trapezoidal solar cells for space applications having dimensions of approximately 4 cm×6.6 cm (area 26.6 cm 2 ). Several cells are integrated on a common blanket polyimide sheet and interconnected, as shown schematically in FIG. 26 .
[0112] The thin encapsulated solar cell structure is shown schematically in FIG. 27 and has a total thickness of 200-250 μm. Adhesive layers are used on either side of the Kapton® layer to attach the IMM cell to the blanket polyimide sheet. This avoids the use of copper cladded substrates and reduces the weight of the blanket considerably.
[0113] Solar cells were integrated on copper-cladded polyimide sheet using electrically conductive adhesive (ECA) which makes full face contact with the backside metal layer, and interconnected using induction soldering, as shown in FIG. 28 . However, the fragile solar cell must be supported at all times with a Kapton substrate (yellow in FIG. 27 ) after removal of the GaAs wafer. This prevents full face contact with the ECA. Furthermore, the ECA has high contact resistance, and delaminated upon rolling. For this reason, it is preferred to contact both sides of the epi-layer from the top of the wafer, as shown schematically in FIG. 29 with a copper ribbon.
[0114] The backside metal layer can be accessed from the top at the GaAs/metal interface by etching a few mm 2 of the GaAs epi-layer to expose the top of the metal layer during processing of the front side, as shown in FIG. 29 a . Subsequently, contact is made between the backside of one solar cell and the front side of the next cell by copper plating. This will mitigate the risk of breaking the thin epi-layer while contacting. The final assembly of the solar cell is shown in FIG. 29 b . Both sides of the epi-layer are contacted from the top side of the wafer. This eliminates the need for copper cladded substrates and ECA. Simple non-cladded polymeric blanket sheet can be used with organic adhesive layers (grey cross-hatched layer).
[0115] A solar cell was encapsulated with Imiclear (previously Corin® XLS) layer available from Hybrid Plastics, Inc in Hattiesburg, Miss. ImiClear is a spray-on fluorinated polyimide nano-composite, which was developed to replace the cover glass for space applications. It has the combination of transparency and UV resistance and ruggedness that make it suitable for space applications. It can be sprayed-on to a thickness between 25 and 50 μm and does not perturb the balance of the structure. It is applied at room temperature and therefore does not exert any thermal stress on the thin solar cell. This provides a process for fabricating a thin flexible solar cell, interconnecting the front and backsides, integrating several cells on a common blanket polyimide sheet, and encapsulating, which applies to both inverted and non-inverted cells.
[0116] It is necessary to flatten the structure of a multi-layer solar cell over a wide temperature range to encompass temperature swings that are encountered on orbit. ANSYS simulation was used to balance the 8-layer solar cell structure of FIG. 27 , over a temperature range of 300° C. from +100° C. to −200° C. by varying the CTE of the blanket polyimide sheet. FIGS. 30 a and 30 b show the deformations of the 8-layer structure at −200° C. for spray-on polyimide thickness of 25 μm and 50 μm, respectively.
[0117] For spray-on polyimide thickness of 25 μm, a CTE of 16.5 ppm/° C. flattens the structure, whereas for spay-on polyimide thickness of 50 μm, a CTE of 20 ppm/° C. flattens the structure. Below this CTE the structure bends upward, whereas above this CTE the structure bends downward. For the value of CTE that balances the structure, the solar cell remains flat over the entire temperature range from +100° C. to −200° C. Thus, the solar cell structure can be balanced over the entire temperature range.
[0118] Controlling the thickness of the spray-on polyimide cover layer within a fraction of a mil is crucial as it affects the transparency and degree of protection of the cell. A change in thickness of only half of a mil (12.5 μm) causes a shift in the UV cut-off wavelength of 15 nm, which can be critical for the performance of the cell. The thickness of spray-on polyimide is controlled precisely by concentration and duration of the spray. Furthermore, the value of the CTE of the blanket polyimide layer required to stress-balance the structure depends on the thickness of the ImiClear cover layer. The 8-layer solar cell structure can be balanced using Novastrat® variable-CTE polyimide, which is available commercially from Nexolve, Inc which is a division of Mantech SRS in Huntsville, Ala.
[0119] A typical triple junction solar cell for space applications produces about 2.2 V and generates a current of 0.45 A at the Maximum Power Point (MPPT), which corresponds to a power output of about 1 W. Thus, producing a total power of 100 KW requires the use of one hundred thousand cells and an area of 300 m 2 . At least 100 cells must be connected in series to produce a voltage >200 V, i.e. 1000 cells can be connected in parallel. High voltage operation is advantageous because it lowers the ohmic power loss.
[0120] Eliminating the need for copper cladded substrate reduces the weight of the blanket sheet. Also the fill factor of the blanket is increased by tiling the cells tightly together and reducing the gap between adjacent cells to less than 100 μm. A polyimide blanket sheet 50 μm thick yields a specific power ratio > — 200 W/Kg and stowed volume efficiency >100 kW/m 3 , suitable for space applications. This yields robust foldable/rollable high efficiency photovoltaic blankets made of IMM cells that are fully encapsulated which remain flat in orbit and which meet the specific power and volume target requirements.
Process for Integrating and Packaging Lifted-Off Solar Cells
[0121] The lifted-off solar cells are integrated on a common blanket polyimide sheet and interconnected in series and parallel using copper electroplating. The process starts by bonding the epi-wafer to Kapton® polyimide substrate in a clean room and then lifting-off the epi-layer using either laser or crack propagation, as described above. After lift-off the thin IMM structures are processed into fully functional solar cells and a new IMM structure is grown on the original GaAs wafer. Anti-reflection coating (ARC) is deposited and metal lines are patterned on the front side of the IMM cell on Kapton to create metal landing pads. A small volume (10 μm×10 μm×10 μm) is etched at the point of interconnect on the edge of the epi-layer as shown schematically in FIG. 29 , to enable access to the backside metal layer. The processing is done wafer scale. Then the wafer is diced to yield two trapezoidal shaped cells. The front side of the solar cell must be protected while mounting on the back side blanket sheet. The solar cells are aligned and mounted on UV tape, such as dicing tape, about 160 μm thick and laid down on the blanket polyimide sheet. The Mylar sheet protective backing is peeled off the backside of the Kapton to expose the adhesive before mounting on the blanket polyimide sheet. Kapton also comes coated with a uniform film of acrylic adhesive 25 μm thick on both sides, similar to double-sided tape, can be used to facilitate attachment of the Kapton to the epi with metal layer and the blanket sheet. This is a product made by DuPont called Pyralux®. The assembly is then heated at 150-200° C. for about an hour under the weight of a few pounds to activate and cure the adhesive layer. The front side tape is then removed by UV exposure. At this point the cells are ready for interconnect by electroplating. The final step in the process is encapsulation by spraying of ImiClear polyimide to the desired thickness.
[0122] The initial bonding of the epi-layer to Kapton by lamination and the electroplating after assembly are done in a clean room. A standard sheet of polyimide (8½″×11″) accommodates 2 rows of 6 cells (6.6 cm×4 cm each), i.e. 6 series and 2 parallel connections. Automated equipment can be used to process in a roll to roll format using 1,000 foot×12″ rolls of polyimide.
[0123] FIG. 31 shows the extension of the backside metal layer beyond the epi-layer and a top view of the interconnect region between two adjacent cells. The cells are interconnected using standard procedures that are well established in the semiconductor industry. FIG. 32 illustrates the process for series connection (steps 1-4, left column) and for parallel connection (steps 1-6, right column). Step 1 illustrates the connections conceptually.
Process for Electroplating Series Connection
[0124] The process starts by coating all surfaces with photoresist, exposing through a mask, and developing leaving all surfaces covered except those that will be coated with dielectric. The samples are then coated with a thin layer of dielectric using Atomic Layer Deposition (ALD), which is particularly effective at coating side walls and sharp edges. All the surfaces are coated with dielectric, including the photoresist. After the photoresist is dissolved the remaining dielectric is shown in Step 2. Subsequently, a second coat of photoresist is applied and patterned, leaving only some areas exposed for electroless Cu plating. Submerging the samples in electroless Cu coats the entire assembly with a thin layer of Cu. Dissolving the second photoresist and the overlying Cu, a thin Cu layer remains over the dielectric in the areas shown in Step 3. This step creates a continuous electrical path from one cell to the next.
[0125] The assembly is then coated with a third layer of photoresist, exposed through a mask and developed; leaving exposed the surfaces that will be electroplated. The samples are submerged in an electroplating bath and Cu is plated to the desired thickness in the areas shown in Step 4. The remaining photoresist is finally removed. Electroplating allows much tighter spacing in the placement of the cells compared to other interconnect methods and a much smaller area of the epi-layer needs to be etched away. The IMM cell would not survive immersion in a plating bath unless it is protected by photoresist.
Process for Electroplating Parallel Connection
[0126] Step 1 (right column) illustrates the concept of connecting two neighboring cells in parallel, which is slightly different from the series connection. There is no need for dielectric coating at the beginning because the two connected metals are at the same level. Electroless Cu is deposited directly after patterning to connect the back side metals, as shown in Step 2, which is followed by electroplating copper by applying a potential to the interconnected back side metal layers in step 3. This is followed by patterning the areas to be covered by a dielectric layer and dielectric deposition using ALD in step 4. The parallel connection requires a second electroless Cu deposition, as shown in Step 5. Finally, the cells are patterned and electroplated one more time, as shown in Step 6. These steps require photoresist deposition, patterning and removal three times as in the series connection. The completed and interconnected cells will be encapsulated using spray-on polyimide.
[0127] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only. | An epitaxially grown layer III-V solar cell is separated from the growth substrate. A sacrificial epitaxial layer is embedded between the GaAs wafer and the solar cell. The sacrificial layer is damaged by absorbing IR laser radiation. A laser is chosen with the right wavelength, pulse width and power. The radiation is not absorbed by either the GaAs wafer or the solar cell. No expensive ion implantation or lateral chemical etching of a sacrificial layer is needed. The solar cell is detached from the growth wafer by propagating a crack through the damaged layer. The active layer is transferred wafer-scale to inexpensive, flexible, organic substrate. The process allows re-using of the wafer to grow new cells, resulting in savings in raw materials and grinding and etching costs amounting to up to 30% of the cost of the cell. Several cells are integrated on a common blanket polyimide sheet and interconnected by copper plating. The blanket is covered with a transparent spray-on polyimide that replaces the cover glass. The solar cell is stress-balanced to remain flat on orbit. | 7 |
This application is a Continuation of application Ser. No. 08/834,478, filed Apr. 11, 1997, now U.S. Pat. No. 6,287,224.
BACKGROUND—FIELD OF THE INVENTION
This invention relates to arrowheads having a recessed collar or body that is slidably positionable about a stem portion thereof.
BACKGROUND—DESCRIPTION OF PRIOR ART
Arrows have long been used for war, hunting and competitive sports. A conventional arrow has a shaft, a nock at one end that receives the bow string, an arrowhead or point that attaches to the opposite end, and fletchings. The fletchings are glued to the shaft near the nock end, and help to stabilize the arrow in flight, as it rotates. Arrowheads generally have a pointed forward end, and an opposite threaded shaft end that attaches the arrowhead to the arrow shaft. Arrowheads are also attached to the forward end of arrow shafts by glueing and other methods.
Arrowheads come in a variety of different sizes and configurations depending on their intended use. For example, there are specifically designed arrowheads for competitive target shooting, shooting fish, hunting birds or small game animals, and for hunting big game animals.
The most common type of arrowhead used in hunting is the fixed-blade arrowhead, which has a pointed tip end used for penetrating, and blades that each have a razor sharp edge for cutting. Most conventional fixed-blade arrowheads have replaceable blades which are held in a fixed position on the arrowhead. The replaceable blades attach to the arrowhead body in longitudinal grooves called blade slots. The tip of the arrowhead may be separably attachable to the arrowhead body or may be integral with it. Arrowheads for hunting are generally known as broadheads.
Arrowheads used for hunting kill the game animal by cutting vital organs such as the lungs and vascular vessels such as arteries, which causes rapid hemorrhaging and/or suffocation. Quick and humane kills are dependent on accurate shot placement, and upon the amount or volume of the animal tissue that is cut. Hunting arrowheads that cut more tissue are more lethal, and therefore are better. The volume of tissue that is cut is determined by the cutting diameter of the arrowhead, the number of blades it contains, and by the distance the arrowhead penetrates into the animal. The cutting diameter of an arrowhead is determined by how far each cutting blade extends outward from the arrowhead body. The further the blades extend outward the larger the cutting diameter is, and therefore the more cutting potential the arrowhead has.
A problem with conventional fixed-blade arrowheads is that having the desirable, large cutting diameters generally cause unstable arrow flight or poor arrow aerodynamics, which affects accurate shot placement. This can lead to non-lethal wounding of the game animal or missing the animal altogether. Unstable arrow flight in hunting arrows is generally caused by arrowhead aligning and centering problems. Arrowhead aligning and centering problems are prevalent when the arrowhead is attached to the arrow shaft such that the longitudinal axis of the arrowhead is not in line with the longitudinal axis of the arrow shaft. Alignment and centering problems in arrowheads are generally created by low tolerances or sloppiness in the manufacturing of the arrowhead body. When a mis-aligned arrowhead is attached to an arrow and the arrow is shot, as the arrow spins or rotates in flight non-stabilizing forces are induced on the front end of the arrow and cause inconsistent or erratic flight, which steers the arrow from its intended path. Since the cutting blades of fixed-blade arrowheads extend out from the arrowhead body when the arrowhead is in flight, the blades greatly magnify any non-stabilizing forces induced on the arrow from misalignment, and therefore increase erratic arrow flight. This is the main reason why conventional fixed-blade arrowheads are limited in the maximum cutting diameter they can have, while retaining sufficiently stable aerodynamics.
To create a hunting arrowhead that has both a maximum cutting diameter and stable aerodynamics, despite moderate manufacturing tolerances, blade-opening arrowheads were designed. Blade-opening arrowheads differ from conventional fixed-blade arrowheads in that the cutting blades are folded up or held adjacent to the arrowhead body in a retracted position while the arrow is in flight, but at impact with the game animal rotate or pivot into an open position, therefore exposing the sharp blade edges and cutting the animal. Since the blades of blade-opening arrowheads are held adjacent to the arrowhead body and do not extend very far out from it, any aligning or centering problems of a blade-opening arrowhead attached to an arrow will not noticeably steer the arrow or undesirably affect its flight trajectory. In this manner blade-opening arrowheads can have both a desirable large cutting diameter, and the stable arrow flight characteristics necessary for accurate shot placement. Blade-opening arrowheads can therefore potentially be more lethal.
Blade-opening arrowheads like conventional fixed blade arrowheads generally have an elongated arrowhead body, a tip end, and a threaded opposite end. The blades of blade-opening arrowheads have an attachment end which attaches the blades to the arrowhead body by a pivot pin, so that the blades can pivot or rotate between the retracted position and the open position. Blade-opening arrowheads also come in a variety of different types and styles. The blades of the most common type of blade-opening arrowheads, when in the retracted position have a leading blade end positioned near the tip of the arrowhead that protrudes outward from the arrowhead body, and is some times shaped like a wing. The leading blade ends of the most common type of blade-opening arrowheads, rotate away from the arrowhead body in a rearward direction when penetrating an animal. Particularly, the leading blade ends catch on the animal's surface and serve to lever or rotate the blades into the open position. The blades of blade-opening arrowheads are also received in blade slots, which are machined or formed into the side of the arrowhead body.
Blade-opening arrowheads for hunting big game must be non-barbing, wherein the blades when in the open position must not inhibit or prevent arrow extraction from a game animal by barbing into the animal tissue. This makes it so non-fatally wounded animals can easily pull out an arrow still lodged in them. For an arrowhead to be non-barbing, the pivotal blades must rotate from the open position to an angle greater than ninety degrees, as measured between the rear edge of each blade and a location on the arrow shaft rearward of the blades.
Blade-opening arrowheads generally do not penetrate as deep as conventional fixed-blade arrowheads. Sometimes in hunting situations an arrow will not completely pass through the game animal and will not have sufficiently cut any vital organs or vascular vessels, and thus not having inflicted a lethal wound. Sometimes in these instances the arrowhead will have penetrated within the game animal near an artery or vital organ such that as the animal retreats, the arrowhead continues to cut as it moves within the animal, and the artery or vital organ is severed, and the animal is harvested. Conventional blade-opening arrowheads are generally not as lethal in these types of situations, as arrowheads having the cutting blades positioned near the tip of the arrowhead, such as conventional fixed-blade arrowheads. This is because the cutting blades of the most popular types of conventional blade-opening arrowheads when in the open position, are positioned approximately one and a half inches back from the arrowhead tip, and therefore cut a lesser volume of tissue despite equal arrowhead penetration depth.
To hold the blades of blade-opening arrowheads in the retracted position during flight until the arrowhead penetrates the animal, annular retention members such as O-rings are most commonly used. Other commonly known annular retention members are, rubber bands, tight fitting plastic sleeves, tape, heat-shrinkable fitting plastic sleeves, and other wrap materials. When the O-rings are stretched around the outside of the blades they exert a resistive force against the blades and hold the blades selectively in the retracted position.
O-ring use for blade retention is less than ideal. The elastomeric polymer materials are susceptible to drying-out and therefore cracking, which can lead to breaking of the O-ring during arrow acceleration when the arrow is shot. This will cause premature blade-opening and produce extremely erratic arrow flight and possible non-lethal wounding of the game animal. This may also cause severe lacerations to the archer. Also, bows shooting arrows at very high speeds can require as many as three O-rings to prevent premature blade-opening. The experience of learning this can be very undesirable for the archer. O-rings are a consumable item designed for one shot use, and the cost of constantly replacing them is a detrimental factor. Also, they are not user-friendly and are a general bother to worry about while out in the field.
Aside from consumer use considerations, humaneness to the hunted game animal is an important consideration as well. When the arrowhead penetrates the animal and the blades begin to rotate open, the more the O-ring is stretched the more resistive force it exerts back against the blades, thus impeding the rate of blade-opening. This can possibly prevent full blade-opening and a quick and humane kill. Also, extreme weather temperatures greatly affect the elasticity of O-rings; cold weather decreases elasticity which increases the likelihood of the blades not opening, and hot weather increases elasticity which increases the likelihood of premature blade opening.
Attempts in the prior art have been made to remedy the problems associated with O-ring use for blade retention of blade-opening arrowheads, but these attempts have their own problems as well. For example, the use of magnetism for blade retention is known to the art. The disadvantages of using magnets for blade retention are that magnets are heavy, relatively expensive, and can demagnetize. The use of a leaf spring for blade retention is also known to the art, where the leaf spring is positioned and held in the blade slot by a set-screw, which is usually also the pivot pin. One disadvantage of using a leaf spring for blade retention is the difficulty involved when replacing the blades; having to simultaneously line up a hole in the leaf spring, a hole in the blade, and a hole in the arrowhead body while inserting a set screw through all three members, for each blade. Another disadvantage of using a leaf spring for blade retention is limitations of the leaf spring, where a very small amount of dirt, debris or ice can prevent the leaf spring from deflecting, and also, the flexibility life span of the leaf spring can be short. This could possibly inhibit blade-opening altogether. Disadvantages of other blade retention methods known to the art are, reduced penetration of the arrowhead, structural weakening of various arrowhead elements, in-operability, and manufactural unfeasibleness.
It is apparent that there are much needed improvements in blade-opening arrowheads, both in consideration of the archery consumer and the hunted game animal.
It is apparent that there is a need for a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner, by methods other than O-rings or similar consumable elements, that is user-friendly, manufacturally feasible, and structurally strong.
It is also apparent that there is a need for a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner, that is operable and is not suspectable to malfunctioning by contamination of dirt, debris, or ice and/or by short life span of the blade retention method.
It is yet further apparent that there is a need for a blade-opening arrowhead that is capable of driving the razor cutting edges of the blades from the open position, forwardly into uncut or unpenetrated tissue of an arrowed game animal when the arrow is lodged in the animal, especially when the animal has not been fatally or lethally hit, thus to increase the lethality of the arrowhead, and to be more humane to the animal.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide blade-opening arrowheads with blade retention methods that do not require the use of consumable annular members such as O-rings.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted in-flight position, in a secure or locked manner by methods other than O-rings or similar elements, that is user-friendly, manufacturally simple, and structurally strong.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted in-flight position, in a secure or locked manner that is operable and is not suspectable to malfunctioning, especially by contamination of dirt, debris, ice and/or by short life span of the blade retention method.
It is another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner by releasably latching the blade edge of each blade to the arrowhead body or equivalent. Specifically where an urging force urges the blades in a forward direction to securely hold the edge of each blade engaged against the arrowhead body, and therefore the blades are securely held adjacent to the arrowhead body when in a retracted position but freely rotate into an open position when the arrowhead penetrates an object.
It is still another object of the present invention to provide a blade-opening arrowhead that securely holds each blade selectively in a retracted or in-flight position, in a secure or locked manner by releasably latching the blade edge of each blade to a holding element. Specifically where an urging force urges the holding element to securely hold the edge of each blade engaged against the holding element, and therefore the blades are securely held adjacent to the arrowhead body when in a retracted position but freely rotate into an open position when the arrowhead penetrates an object.
It is yet further another object of the present invention to provide a blade-opening arrowhead that is capable of driving or continually urging the razor cutting edge of each blade from the open position, forwardly into uncut or unpenetrated tissue of an arrowed game animal.
The foregoing objects and advantages and other objects and advantages of the present invention are accomplished with a hunting arrowhead that attaches to the forward end of an arrow shaft, where a plurality of blades are pivotally connected to an arrowhead body. The blades freely rotate from an in-flight retracted position to an open position when the arrowhead penetrates an object, or when acted upon by a sufficient opening force. When the blades are in the in-flight retracted position they are securely held selectively adjacent to the arrowhead body by engagement of a blade edge of each blade to a holding element.
Such a blade-opening arrowhead according to one preferred embodiment of this invention has an arrowhead body with a tip end used for initial penetration and an opposing threaded shaft end that screws or threads the arrowhead to an arrow. The tip end may be removably attached to the arrowhead body, and may be made of material different than the rest of the arrowhead body. The arrowhead body has a plurality of blade slots, one for each respective blade. Each blade has a first end, an opposing second end and an edge extending about its periphery. One blade edge of each blade is sharpened for cutting. The first blade ends or the leading ends each have a protruding wing that is exposed out from the arrowhead body when the blades are in the retracted position. The wings serve to increase the moment-arm for levering or rotating the blades to the open position. The second end of each blade has an aperture or hinge pin receiving hole for receiving a pivot pin or a hinge pin. The arrowhead body also has a hinge pin receiving hole for each blade. The arrowhead body hinge pin receiving holes are recessed or drilled into the two opposing sidewalls of each blade slot, and are threaded to receive the threaded hinge pins. A single hinge pin is used for each blade, and when the blades are positioned in the blade slots, each hinge pin is extended through the aperture of a corresponding blade and is screwed into the arrowhead body. This pivotally connects the blades to the arrowhead body. The cross-sectional area or open area of each blade aperture is greater than the cross-sectional area of its corresponding hinge pin, such that a gap is created between each hinge pin and blade aperture of each blade, when the hinge pins are extended through the blade apertures. These gaps allow each blade to freely move in a forward and rearward direction independent of the arrowhead body and corresponding hinge pin. The blade edge of the first end of each blade has a catch lip or a bump protruding out from it near the cutting edge. The arrowhead body has one receiving notch or holding element formed in it for each blade. The notches are situated near the top of each blade slot and are recessed into the arrowhead body. An annular recess encircling the arrowhead body is situated below the blade slots, and is recessed into the arrowhead body. This annular recess communicates with each blade slot and leaves or defines a stem shaped portion on the arrowhead body. An annular compression spring or coil spring is positioned in the annular recess, with a separate annular ring positioned forward or above the annular spring. Both the annular ring and annular spring are slidably positioned around the stem portion of the arrowhead body, such that the annular ring contacts the second end of each blade. An annular blade-stop washer shaped like a doughnut, also having a recessed portion shaped to contain the annular spring, is slidably positioned around the arrowhead body stem below the annular spring, and contacts the rear end of the annular spring. The blade-stop washer has a sloped outer and upper side, that serves to abut against the blades when they are rotated to the fully open position, thus defining the cutting diameter of the arrowhead when the blades are in the fully open position.
When a blade-opening arrowhead according to the preferred embodiment of this invention as described above, is tightly fastened to the forward end of an arrow shaft, the blade-stop washer is tightened-up against both the arrow shaft and the arrowhead body. This tightening causes the annular spring to be compressed between the blade-stop washer and the annular ring. This compression or biasing of the spring causes an urging force to be exerted against the second ends of the blades in a generally axial direction. The annular ring serves to transfer the urging force equally to all blades. Since a gap exists between each hinge pin and each blade aperture, the urging force moves the blades forward relative to the arrowhead body, and engages or receives the catch lips on the blades into their corresponding receiving notches in the arrowhead body. The continual compression of the annular spring provides a continual urging force which maintains the engagement of the catch lips and notches, thus releasably latching and securely holding the blades selectively in the retracted position. The urging force is strong enough to maintain the blades in the retracted position when the arrow is exposed to incidental forces, such as those produced from transporting the bow, nocking an arrow to the bow string, and acceleration when the arrow is shot. The urging force is weak enough however, to be easily overcome when the arrow impacts or begins to penetrate a game animal.
When the arrowhead according to the above described preferred embodiment initially penetrates an animal, the first ends or leading ends of the blades catch on the animal's surface and the blades are driven rearwards which unlatches the blades. At initial penetration the annular spring is then compressed such that the catch lips are disengaged from the notches sufficiently that the blades lever-out and freely rotate towards the open position. With the blades in the open position, the urging force of the annular spring continually urges the cutting edges of each blade in a forward direction, providing the ability to further cut additional animal tissue, should the arrow still be lodged in the animal.
All that is required to securely lock the blades back in the retracted position, is to simply push each blade back into the retracted position, and the spring compresses as the catch lips are received back into the notches. Once the catch lips are received into the notches, the continual urging force of the spring simply maintains the blades in the retracted position again. Also, when the sharp edges of the blades become dull, all that is required to change the blades is to un-compress the spring by slightly unscrewing the arrowhead from the arrow shaft, and then remove the threaded hinge pin, insert a new blade, and re-insert the hinge pin. There is no requirement to spend additional time and effort lining up tiny holes in other tiny elements such as a leaf spring, with the blade aperture and arrowhead body pivot pin receiving hole, when changing blades or when replacing the spring element or elements.
Blade-opening arrowheads according to other preferred embodiments of this invention differ from the above described preferred embodiment in that they have an annular hinge pin, where the plurality of blades are all attached to the single annular hinge pin. The annular hinge pin is slidably positioned on the stem located near the rear end of the arrowhead body, and is received in the same annular recess as the annular spring and annular ring. According to one such annular hinge pin embodiment, there is substantially no gap between the hinge pin and each blade aperture, and the blades and hinge pin are both urged or moved forward together by the annular spring when the catch lips are received or engaged into the notches. In another annular hinge pin preferred embodiment according to this invention, a gap is formed between the hinge pin and each blade aperture, and the blades are urged or biased by the annular spring when the catch lips are received into the notches.
A blade-opening arrowhead according to another preferred embodiment of this invention, also has an annular recess encircling the arrowhead body, situated below the blade slots, which defines a stem shaped portion on the arrowhead body, and which houses an annular spring and an annular ring. The blade-opening arrowhead according to this preferred embodiment has a catch lip and an adjacent notch in the second end of each blade. Each notch is positioned medial to its corresponding catch lip when the blades are in the retracted position. Each notch is defined by its corresponding catch lip, wherein the notches were created by removal of blade material in fabricating the protruding catch lips. The annular spring urges the annular ring against each catch lip and into each notch, thus engaging the blade edges at the second end of each blade, and securely holding the blades selectively adjacent to the arrowhead body when in the retracted position. The blades are prevented from rotating outwards prematurely by the lateral or outside edge of each blade notch abutting against the lateral surface of the annular ring. When the blade-opening arrowhead according to this preferred embodiment impacts a game animal and the blades begin rotating outwards, the catch lips or lateral edges of the notches are driven into the annular ring, which compresses the annular spring such that the tip of each catch lip slips over the annular ring, thus disengaging the annular ring from the notches and thus allowing the blades to freely rotate towards the open position.
According to another preferred embodiment of this invention, an annular spring is positioned in an annular recess situated near the forward end of the arrowhead body within a separably attachable tip piece. The blade-opening arrowhead according to this preferred embodiment has a catch lip and an adjacent notch in the first end of each blade. Each notch is positioned lateral to its corresponding catch lip when the blades are in the retracted position. Also the notch and catch lip of each blade are situated near the cutting edges of the blades. Each notch is defined by its corresponding catch lip, wherein the notches were created by removal of blade material in fabricating the protruding catch lips. The annular spring urges the annular ring against each catch lip and into each notch in a rearward generally axial direction, thus latching the blade edges and securely holding the blades selectively adjacent to the arrowhead body in the retracted position. The blades are prevented from rotating outwards prematurely by the medial or inside edge of the blade notches abutting against the medial surface of the annular ring. When the arrowhead impacts an animal and the blades begin to rotate outwards, the catch lips are driven into the annular ring, which forces the annular spring to compress until the catch lips freely slip under the annular ring. In this manner the blades are unlatched and freely rotate towards the open position.
The blade-opening arrowheads according to this invention, use no consumable items such as O-rings, for blade retention. The blade retention methods of the blade-opening arrowheads according to this invention, are simple and user-friendly. The blade-opening arrowheads according to this invention provide blade retention methods that are not suspectable to malfunctioning when exposed to the harsh conditions commonly encountered in the field, and when subjected to prolonged use. Should ice, dirt or debris get intermingled with the annular spring of the type preferred for use according to this invention, the annular spring will still serve to produce an effective blade retention urging force, and to allow the timely opening of the blades at target impact. This is so because the spaces between the spring coil wires are large enough to handle a relatively large accumulation of foreign matter, yet have room to allow adequate spring compressing. Also, the length of spring flexibility life of the annular spring according to this invention, under normal use considerations, is indefinite. This is such because the diameter or gauge of the wire, and the general diameter of the spring are large enough that the annular spring is extremely rugged and durable in nature, especially when compared to the relatively light work load required of it.
The blade-opening arrowheads according to this invention are also more humane, and more lethal than prior art arrowheads. Should the arrow become lodged in the game animal, particularly when the animal has not been fatally hit, the blades will be driven or continually urged in a forward direction by the urging force of the annular spring, cutting additional tissue, which could possibly sever any nearby arteries or vital organs, and thus decrease the wounding loss. This trait of cutting additional tissue is a feature that no prior arrowhead performs. The blade-opening arrowheads, according to this invention are also structurally strong, simple and feasible to manufacture, and operable.
As has been shown in the above discussion, the blade-opening arrowheads according to this invention overcome deficiencies inherent in prior art arrowheads.
With the above objects and advantages in view, other objects and advantages of the invention will more readily appear as the nature of the invention is better understood, the invention is comprised in the novel construction, combination and assembly of parts hereinafter more fully described, illustrated, and claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of an arrow with a blade-opening arrowhead according to one preferred embodiment of this invention attached to the forward end of the arrow shaft, with the blades in the retracted position;
FIG. 2 is a full length longitudinal cross-section of the preferred embodiment as illustrated in FIG. 1, but showing a plurality of two blades pivotally connected to the arrowhead body, with the blades in the retracted position. The annular ring and annular spring are shown in perspective view;
FIG. 3 is a full length longitudinal cross-section of a blade-opening arrowhead as illustrated in FIG. 2, showing initial rearward blade displacement occurring at initial penetration of an object;
FIG. 4 is a full length longitudinal cross-section of a blade-opening arrowhead as illustrated in FIG. 2, showing the blades rotating away from the arrowhead body after initial penetration of an object;
FIG. 5 is a full length longitudinal cross-section of a blade-opening arrowhead as illustrated in FIG. 2, showing the blades in the fully open position with the annular spring continually urging the blades forward;
FIG. 6 is an exploded full length longitudinal cross-section of a blade-opening arrowhead as illustrated in FIG. 2 . The hinge pins, annular ring, annular spring and blades are shown in perspective;
FIG. 7 is a full length longitudinal cross-section of a blade-opening arrowhead according to another preferred embodiment of this invention, similar to the preferred embodiment shown in FIG. 2, but without an annular ring;
FIG. 8 is a full length longitudinal cross-section of a blade-opening arrowhead according to another preferred embodiment of this invention, showing the annular spring urging the annular ring into a notch in each blade. The hinge pins, annular ring, annular spring and blades are shown in perspective. An additional detached blade is shown also;
FIG. 9 is a full length longitudinal cross-section of a blade-opening arrowhead according to another preferred embodiment of this invention, showing an annular hinge pin slidably positioned on the arrowhead body, with substantially no gap between the blade apertures and annular hinge pin. The annular hinge pin is shown in a top view also;
FIG. 10 is a full length longitudinal cross-section of a blade-opening arrowhead similar to the blade-opening arrowhead illustrated in FIG. 9, but without an annular ring. The annular hinge pin is shown in a top view also;
FIG. 11 is a full length longitudinal cross-section of a blade-opening arrowhead according to another preferred embodiment of this invention, similar to the preferred embodiment illustrated in FIG. 9, except a gap is formed between the blade apertures and hinge pin. The annular hinge pin is shown in a top view also;
FIG. 12 is a full length longitudinal cross-section of a blade-opening arrowhead similar to the blade-opening arrowhead illustrated in FIG. 11, but without an annular ring. The annular hinge pin is shown in a top view also;
FIG. 13 is a full length longitudinal cross-section of a blade-opening arrowhead according to another preferred embodiment of this invention, showing a plurality of blades pivotally connected to the arrowhead body, with the blades in the retracted position. The annular ring and annular spring are shown in perspective;
FIG. 14 is a full length longitudinal cross-section of a blade-opening arrowhead according another preferred embodiment of this invention, similar to the preferred embodiment shown in FIG. 13, showing a plurality of blades pivotally connected to the arrowhead body, with the blades in the retracted position, but without an annular ring; and
FIG. 15 is an exploded full length longitudinal cross-section of a blade-opening arrowhead as illustrated in FIG. 13 . The hinge pins, annular ring, annular spring and blades are shown in perspective.
REFERENCE NUMERALS IN DRAWINGS
16
arrow
17
nock
18
arrow shaft
19
fletching
20
blade-opening arrowhead
21
blade-opening arrowhead
22
blade-opening arrowhead
23
blade-opening arrowhead
24
blade-opening arrowhead
25
blade-opening arrowhead
26
blade-opening arrowhead
27
blade-opening arrowhead
28
blade-opening arrowhead
30
arrowhead body
32
tip
34
stem
36
blade-stop washer
38
hinge pin receiving hole,
arrowhead body
40
notch, arrowhead body
42
sidewall of arrowhead body
44
notch, blade
46
second notch, blade
50
blade
52
aperture
54
inner edge, cutting edge
56
outer edge
58
distal edge
60
catch lip
62
proximal edge
64
wing
66
side of blade
68
blade slot
70
hinge pin
72
annular recess, arrowhead body
74
annular recess, blade-stop
washer
76
annular recess, tip
78
abutting shoulder, arrowhead
body
80
annular spring
82
annular ring
84
annular hinge pin
90
gap
100
opening force
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-6 illustrate a preferred embodiment according to this invention wherein FIG. 1 shows a conventional arrow 16 , having a nock 17 for receiving a bow string, an arrow shaft 18 , stabilizing fletchings 19 , and a blade-opening arrowhead 20 attached to the forward end of the arrow shaft 18 . The stabilizing fletchings 19 are helically mounted on the arrow shaft 18 , which causes the arrow 16 to spiral or rotate in flight, which greatly enhances accuracy. Blade-opening arrowhead 20 , in FIG. 1, shows a plurality of three blades 50 pivotally connected to an arrowhead body 30 , each by a hinge pin 70 that is threaded or screwed into a corresponding threaded hinge pin receiving hole 38 in arrowhead body 30 . Hinge pin receiving hole 38 passes through the opposing sidewalls of a corresponding blade slot 68 , for each blade 50 . An aperture 52 in one opposing end of each blade 50 has hinge pin 70 extending therethrough, when blades 50 are pivotally connected to arrowhead body 30 . Each blade 50 rotates between a retracted position where the edges of blades 50 are engaged and releasably latched to holding means, as shown in FIGS. 1 and 2, and an open position as shown in FIG. 5 where the other opposing blade end of each blade 50 is rotated away from arrowhead body 30 . A gap 90 is formed between each hinge pin 70 and aperture 52 , such that each blade 50 is free to move relative to corresponding hinge pin 70 and arrowhead body 30 . Hinge means connect each blade 50 to arrowhead body 30 .
Hinge means, according to this invention, are intended to comprise any suitable element or elements that serve to pivotally connect each blade 50 to arrowhead body 30 . As shown in FIGS. 1-8 and 13 - 15 according to some preferred embodiments of this invention, straight hinge pins 70 are received in apertures 52 located near a second blade end or a proximal blade edge 62 , of each corresponding blade 50 . As shown in FIGS. 9-12 according to other preferred embodiments of this invention, annular hinge pin 84 is received in apertures 52 of a corresponding plurality of blades 50 , near the second end of each blade or proximal blade edges 62 . Any shape of aperture 52 and any pin 70 , 84 , received therein will suffice for hinge means. Hinge means may comprise rod or bar stock, bearing members such as a ball bearing, and protrusions or bumps machined or formed into the arrowhead bodies 30 , and the like, and may be straight or curved such as annularly, and may accommodate, have connected thereto or have received thereon a plurality of blades 50 , or a single individual blade 50 . The hinge means according to this invention may attach to the arrowhead body 30 slidably, or be screwed or threaded on. It is apparent that apertures 52 may not communicate with the peripheral edges of blades 50 thereabout, thus creating a through hole, or that apertures 52 may communicate with the peripheral edges of blades 50 .
Referring to FIGS. 1-6, wherein FIG. 2 shows a blade-opening arrowhead 20 , identical to blade-opening arrowhead 20 as illustrated in FIG. 1, but for reasons of clarity having only two blades 50 , which are superimposed upon a longitudinal cross-section or cutaway of arrowhead body 30 . Each blade 50 has a pair of blade sides 66 , and is positioned in a respective blade slot 68 that communicates with an outer sidewall 42 of arrowhead body 30 . An annular spring 80 and an annular ring 82 shown in perspective view in FIG. 2, are positioned slidably about a stem 34 of arrowhead body 30 . Annular spring 80 and annular ring 82 are positioned in an annular recess 74 of a blade-stop washer 36 and an annular recess 72 of arrowhead body 30 . Both annular recesses 72 , 74 encircle about the longitudinal axis of blade-opening arrowhead 20 . Each blade 50 when in the retracted position has an inner edge 54 extending generally longitudinally between opposing blade ends, and an outer edge 56 extending generally longitudinally between opposing blade ends. Also, a distal edge 58 extends between inner edge 54 and outer edge 56 at the first end or leading ends of blades 50 , and a proximal edge 62 extends between inner edge 54 and outer edge 56 , at the second end or hinge connecting ends of blades 50 .
Blade-stop means, such as blade-stop washer 36 , according to this invention, serve to abut outer edge 56 of each blade 50 when blades 50 are in the fully open position as illustrated in FIG. 5, thus defining the cutting diameter of arrowhead 20 . Blade-stop means according to this invention comprise any element that serves to abut against blades 50 , thus stopping their opening rotation. It is apparent that outer blade edges 56 may abut arrowhead body 30 or an equivalent, to lessen the impact forces transferred to the hinge means.
Selectively retaining blades 50 in a retracted or in-flight position according to this invention is intended to mean that the position blades 50 are placed in is selectable, or that blades 50 can be positioned in more than one position. Preferably selectable blade positions according to this invention are the retracted position and the open position. Blades 50 are securely held in the retracted position or in a first selectable position in a locked manner until acted upon by an opening force 100 , whereupon they freely rotate to the open position, or a second selectable position.
According to the preferred embodiment illustrated in FIGS. 1-6, annular ring 82 is biased into or against proximal edges 62 of each blade 50 when annular spring 80 is compressed. When arrowhead 20 is tightly fastened to arrow shaft 18 , blade stop washer 36 is snugged up to both arrowhead body 30 and to arrow shaft 18 . This compresses annular spring 80 such that annular spring 80 biases annular ring 82 into blades 50 . The forward displacement of annular ring 82 and annular spring 80 is limited by an abutting shoulder 78 , as shown in FIG. 6 . This biasing or compressing of annular spring 80 produces an urging force which urges blades 50 in a forward direction such that a catch lip 60 on distal blade edge 58 of each blade 50 is received or engaged in a corresponding receiving notch 40 . Notches 40 are recessed into arrowhead body 30 near the forward end of each corresponding blade slot 68 . When catch lips 60 are received into notches 40 the edges of blades 50 are releasably latched and engaged such that blades 50 are securely held selectively adjacent to arrowhead body 30 in the retracted position. When arrow 16 having blades 50 in the retracted position, as shown in FIG. 1, is shot and impacts an animal or an object, and begins initial penetration, as shown in FIG. 3, a wing 64 projecting out from blade edges 56 and 58 of each blade, catches on the animal's surface and opening force 100 drives blades 50 rearwardly. As is clearly shown in FIG. 3 at initial penetration or impact, annular spring 80 is compressed, such that gaps 90 are below hinge pins 70 , and catch lips 60 are effectively disengaged from notches 40 so that blades 50 are unlatched. As shown in FIG. 4, while penetrating the animal or object after initial impact, blades 50 begin to rotate away from arrowhead body 30 , towards the fully open position. As illustrated in FIG. 5, when blades 50 are in the open position the continual urging force produced by annular spring 80 drives or continually urges cutting edge 54 of each blade 50 in a forward direction, further slicing uncut or unpenetrated tissue. When arrowhead 20 is pulled-out from a target or a game animal blades 50 rotate from the fully open position to a non-barbing position as clearly shown in FIG. 4, wherein the angle between blade edges 56 of each blade and a point rearward of hinge pins 70 on arrow shaft 18 is greater than ninety degrees. It is apparent that wing 64 can be positioned at different locations along blade edge 56 of each blade 50 , specifically to create an open-after impact blade-opening arrowhead, as is known to the art.
Bias means according to this invention, comprise any element or elements that produce an urging force. Bias means according to this invention can comprise, but not be limited to, any resilient, compressible, deflectable, flexible, or stretchable mechanical member or members and the like, which have the ability to substantially return to their original state, such that an urging force is generated in a direction substantially opposite the direction the bias element or bias means is deformed. Bias means may include a single bias element urging a plurality of blades, or may be an individual bias element for each blade, or a combination thereof. Bias means for example, can include, cantilevers, rubber material, certain hydraulic systems and/or filled bladder systems, and springs such as compression, coil or leaf. The bias means can be fabricated of metal, plastics or composites. In the preferred embodiments according to this invention, bias means produce an urging force which is preferably strong enough to securely hold the pivotal blades 50 retained in the retracted position when exposed to incidental forces, but yet is weak enough to be quickly and immediately overcome when penetrating an object, such that razor cutting edges 54 are timely exposed, and the penetrated object is maximumly cut. According to this invention compressible annular spring 80 mounted on arrowhead body 30 to bias against the edges of blades 50 when blades 50 are in the retracted position, may include or mean that annular spring is biasing an element into the edges of blades 50 other than itself, such as annular ring 82 .
Means for continually urging cutting edges 54 of the blades 50 forward when in the open position may comprise the bias means according to this invention.
FIG. 7 illustrates blade-opening arrowhead 21 , another preferred embodiment according to this invention. Blade-opening arrowhead 21 is similar to blade opening arrowhead 20 except annular ring 82 is omitted. It is apparent that the operation of blade retention according to the scope of this invention is attainable without use of annular rings or equivalents, such as annular ring 82 .
FIG. 8 illustrates blade-opening arrowhead 22 , another preferred embodiment according to this invention which is similar to blade-opening arrowheads 20 and 21 , except blade-opening arrowhead 22 has no receiving notches in arrowhead body 30 , but rather has a notch 44 and adjacent catch lip 60 in proximal edges 62 of each blade 50 . As is clearly illustrated in FIG. 8, when blades 50 are in the retracted position catch lips 60 are positioned immediately lateral of notches 44 . To securely hold blades 50 of arrowhead 22 selectively adjacent to arrowhead body 30 in the retracted position, the urging force produced by annular spring 80 urges annular ring 82 into notches 44 and against catch lips 60 of each blade 50 . This engages each edge of blades 50 to annular ring 82 , which prevents blades 50 from rotating towards the open position prematurely or until acted upon by a sufficient opening force 100 . When arrowhead 22 is shot and impacts an animal, and begins initial penetration, wings 64 projecting out from blade edges 56 and 58 of each blade, catch on the animal's surface and opening force 100 drives blades 50 rearwardly, thus disengaging blade edges 62 and allowing blades 50 to freely rotate to the open position. It is apparent that another notch 46 can be situated in outer edge 56 of each blade near apertures 52 , such that when blades 50 are in the fully open position annular ring 82 is matingly received or engaged in such other notches. It is also apparent that annular ring 82 or annular spring 80 can contact blade edges 62 of each blade, medially of, in line with, or lateral of, the cross-sectional center of corresponding hinge pins 70 . According to this invention catch lips 60 of each blade 50 comprise a protruding point or tip and inclined sides, so that when annular spring 80 urges annular ring 82 against catch lips 60 of each blade 50 or when annular spring 80 is biased against catch lips 60 , the sides of catch lips 60 are contacting the bias means and/or holding means.
Holding means according to this invention comprise any surface or surfaces, whether integral with, or separably attachable from, arrowhead body 30 , which are capable of being in contact with a specific area or areas of the edge of each blade, to engage with such blade edge areas such that blades 50 are securely held selectively adjacent to arrowhead body 30 when blades 50 are in the retracted position. Holding means according to this invention may also comprise the blade edge or specific areas of the blade edge, in addition to the surfaces that contact the blade edges as discussed above. For example, holding means may comprise catch lips 60 and notches 40 .
According to the preferred embodiments of this invention retaining means comprise bias means and holding means, where an urging force produced from the bias means engages the holding means to the edge of each blade 50 , such that each blade 50 is securely held selectively adjacent to arrowhead body 30 when in the retracted position.
According to this invention engagement, or engaging and disengaging, of a blade edge to holding means has the intended meaning that when blades 50 are held in the retracted position the engaging areas of the blade edges are engaged with the holding means such that they are in contiguous or intimate contact with the holding means, and then when blades 50 are acted upon by a sufficient opening force 100 the specific engaging areas of the blade edges are disengaged such that they are no longer in contiguous or intimate contact with the holding means.
Releasably latching, or latching and unlatching, of a blade edge to holding means according to this invention, as used throughout this specification and in the claims, has the intended meaning that substantially no part of the blade edge of each blade is in contact with the holding means after disengagement of the holding means from the specific blade edge engaging area or areas. Contrastingly, O-rings and the like, remain in contact with the blade edges for a significant portion of the blade rotation while the blades are rotating towards the open position, wherein the more the blades rotate towards the open position the more the O-ring is stretched and further stretched, thus impeding the rate of blade opening, until the O-ring is sheared or rolls back.
According to the preferred embodiments of this invention the blade edges are engaged and disengaged to holding means. According to some preferred embodiments of this invention the blade edges are also releasably latched in addition to being engaged and disengaged, whereas in other preferred embodiments of this invention the blade edges are not releasably latched when the blades edges are engaged and disengaged. It is apparent that engaging and disengaging, and releasably latching according to this invention can be interchanged, and/or combined amongst the preferred embodiments of this invention in various different arrangements, without deterring from the scope of the invention.
In the preferred embodiment of this invention as illustrated in FIG. 8, retaining means comprise holding means and bias means, where bias means urge holding means into notches 44 and against catch lips 60 of edges 62 of each blade 50 , to securely hold edges 62 of blades 50 engaged against the holding means. Particularly, the holding means comprises annular ring 82 , and the bias means comprises annular spring 80 which urges annular ring 82 into notches 44 of each blade 50 .
Retaining means according to the preferred embodiments of this invention as illustrated in FIGS. 1-7 and 9 - 15 , releasably latch the edge of each blade 50 such that blades 50 are selectively held in a retracted position until penetrating an object or when subjected to opening force 100 , whereupon blades 50 are unlatched, and freely rotate towards the fully open position.
According to the preferred embodiments of this invention as illustrated in FIGS. 1-7, and 9 - 12 , retaining means comprise holding means and bias means, where the bias means urge blades 50 into the holding means, to securely hold the edges of blades 50 engaged and latched against the holding means. Particularly, the holding means comprises receiving notches 40 and the bias means comprises annular spring 80 which urges catch lips 60 into notches 40 .
In the preferred embodiments of this invention as illustrated FIGS. 13-15, retaining means comprise holding means and bias means, where bias means urge holding means into and against edges 58 of each blade 50 , to securely hold edges 58 of blades 50 engaged and latched against the holding means. Particularly, the holding means comprises annular ring 82 , and the bias means comprises annular spring 80 which urges annular ring 82 into notches 44 of each blade 50 .
FIGS. 13 and 15 illustrate a blade-opening arrowhead 27 according to another preferred embodiment of this invention, where annular spring 80 and annular ring 82 are housed in an annular recess 76 situated within removably attachable tip piece 32 , and annular recess 72 which is positioned near the forward end of arrowhead body 30 . Particularly, according to blade-opening arrowhead 27 bias means comprises compressible annular spring 80 biasing annular ring 82 against distal edge 58 of each blade 50 , and holding means comprises annular ring 82 . Blade-opening arrowhead 27 has substantially no gap between apertures 52 and hinge pins 70 .
FIG. 14 illustrates a blade-opening arrowhead 28 according to another preferred embodiment of this invention, similar to arrowhead 27 , except without an annular ring. Particularly, according to blade-opening arrowhead 28 as shown in FIG. 14, bias means comprises compressible annular spring 80 biased against distal edge 58 , of the first end of each blade 50 , and holding means also comprises annular spring 80 . Accordingly, holding means comprises bias means. When annular spring 80 is urged into notches 44 and against catch lips 60 of distal edge 58 of each blade 50 , blades 50 are engaged and latched in the retracted position.
FIGS. 9-12 illustrate blade-opening arrowheads 23 - 26 according to this invention, which are similar to blade-opening arrowheads 20 and 21 as illustrated in FIGS. 1-7, except annular hinge pin 84 receives the plurality of blades 50 for each arrowhead 23 - 26 . Annular hinge pin 84 is slidably positioned in annular recess 72 around stem 34 of arrowhead body 30 .
FIGS. 9 and 10 illustrate blade-opening arrowheads 23 and 24 which have substantially no gap between apertures 52 of blades 50 and annular hinge pin 84 , wherein both the plurality of blades 50 and annular hinge pin 84 are urged together when engaging or receiving catch lips 60 into notches 40 . Particularly, blade-opening arrowhead 23 uses annular ring 82 to equally distribute the urging force to all blades 50 , whereas blade-opening arrowhead 24 does not.
FIGS. 11 and 12 illustrate blade-opening arrowheads 25 and 26 , having gaps 90 formed between apertures 52 of blades 50 and annular hinge pin 84 , wherein blades 50 are urged when engaging catch lips 60 into notches 40 . Particularly, blade-opening arrowhead 25 uses annular ring 82 to equally distribute the urging force to all blades 50 , whereas blade-opening arrowhead 26 does not. It is apparent that annular hinge pins 84 or hinge pins 70 , gaps 90 , apertures 52 , and blades 50 , can be altered or combined differently than suggested by the various disclosed embodiments of this invention, without deterring from the scope of this invention.
With reference to holding means, tip end 32 of the arrowhead bodies 30 according to this invention, may be removably attachable. For example, tip end 32 may be removably attachable to a substantially frustuconical arrowhead body 30 , as clearly shown in FIG. 2, or may be integral with arrowhead body 30 , as shown in FIG. 9 . Holding means may be comprised of rigid or resilient materials or elements, and may be comprised of voids, notches, cavities, protrusions, lips, or any combination thereof that is suitable to be contiguously engaged with the engaging area or areas of the edge of each blade 50 . For example, holding means may comprise bias means. Accordingly, the engaging area of the blade edge will be configured in any sufficient shape such that when received in, or engaged to, the holding means, each respective blade 50 , is securely held in the retracted position until the arrowhead penetrates an object or the equivalent. The engaging surfaces of each blade edge and the holding means may comprise any combination of configurations of flat, convex, concave, and inclined, such as flat to flat, flat to concave, and concave to convex. For example, a rigid flat surface of the blade edge may be urged into a resilient flat rubber piece, or a flat rigid blade edge may be urged into a flat rigid area on arrowhead body 30 or the equivalent.
According to this invention, each blade is preferably housed in a respective blade slot or equivalent, configured to receive the blade or blades. The blade slot or slots, are in substantial alignment with the longitudinal axis of the arrowhead body, and may be radially or non-radially orientated. The amount each blade or a particular portion of each blade, is exposed outside the arrowhead body may vary, but will be such that the arrowhead exhibits the excellent arrow trajectory and aerodynamics, characteristic of blade-opening arrowheads, and will have a sufficient moment-arm to lever or rotate the blades quickly and freely to the open position. It is apparent that the blade-opening arrowheads according to this invention may have any number of blades, with two, three or four being preferred. It is apparent that the blade-opening arrowheads according to this invention may have stationary or fixed blades attached to the arrowhead body in combination with the pivotal blades. It is apparent that the different and various elements of this invention may be made of light weight and strong materials, such as composites, aluminum alloys, titanium alloys, stainless steels and other metals and materials. It is also apparent that the arrowhead body of the blade-opening arrowheads according to this invention may be fastened to the forward end of an arrow shaft by any method, such as threading into an insert, or glueing.
The user-friendly and durable nature of the blade retention methods according to this invention provide blade-opening arrowheads that are easy to use, failsafe and worry-free. While the arrowheads are exposed to hard use and harsh conditions in the field, the user will appreciate the simplicity and ease involved in their use. The non-consumable nature, of the blade retention methods of the present invention, allows the archer to simply push the blades back towards the retracted position to securely re-lock the blades in the retracted position, thus quickly and easily readying the arrowhead for repeated use. When compared to prior art spring elements in ruggedness, strength and durability, the annular spring of the present invention better retains its flexibility, and ability to produce an effective urging force. Also, the humanness and lethality of blade-opening arrowheads according to this invention are enhanced over conventional arrowheads, in that the razor sharp cutting edges are continually urged forward, thus providing the ability to cut more tissue.
It is apparent that different bias means, hinge means, holding means and other elements and their equivalents, as discussed above and according to other preferred embodiments of this invention, can be changed, or interchanged, or eliminated, or duplicated, or made of different materials, and connected to or associated with adjacent elements in different manners, other than suggested herein, without deterring from the desired results of the blade-opening arrowheads according to this invention.
It is to be understood that the present invention is not limited to the sole embodiments described above, as will be apparent to those skilled in the art, but encompasses the essence of all embodiments, and their legal equivalents, within the scope of the following claims. | Arrowheads, including blade-opening arrowheads as well as other non blade-opening arrowheads having a recessed collar or body that is slidably positionable about a stem portion thereof. The recess bounds and defines an internally contained void of the arrowheads. The collar is defined by having an internal centrally disposed bore extending therethrough so as to enable the collar or washer to be slidably positioned about an extending post or stem member of a corresponding arrowhead body. The collar and created internal void at least in part aid in attaching blades to the respective arrowhead bodies and serve to house various different annular elements that circumscribe the post member or equivalent. | 5 |
TECHNICAL FIELD
The present invention relates to a method of salting cheese.
TECHNICAL BACKGROUND
The manufacture of cheese products usually employs milk or a milk product in a non-concentrated or a concentrated state as starting material. The most essential feature of the manufacture of cheese is an acidifying and/or renneting process whereby the pH-value of the cheese mass is lowered to a value usually below 5.3 to 5.4 by means of either acid generating starter microorganisms or another acidifying starter agent in combination with a simultaneous use of rennet. As a result, the enzymic effect of the rennet ensures the desired formation of cheese by a coagulation of the casein of the milk product.
The ready-made cheese must usually contain salt out of consideration for taste, texture, and shelf life. The microorganisms used by the manufacture of cheese usually necessitate an addition of salt after the finished acidifying process because high concentrations of salt may impede such microorganisms and result in a deteriorated cheese quality. The cheese is usually of a semi-solid or solid texture due to the shaping thereof for instance in a cheese press, and accordingly the succeeding addition of salt can be both difficult and time-consuming.
By the conventional salting of cheese the cheese is usually placed in a brine after a suitable cooling period of typically 12 hours. The brine is often a saturated brine containing approximately 25% by weight of salt (mainly sodium chloride). In order to ensure that the desired salt content, usually 1 to 1.5% by weight of salt, is absorbed in the cheese, said cheese must stay in the brine for approximately 24 hours.
Salting in brine (brining) is a very space-requiring process due to the necessary stay period. To this must be added the costs involved in the equipment and the handling. In order to illustrate the complex structure of a brining plant, reference is made to the cheese brining system described in U.S. Pat. No. 4,815,368 (Nelles). Such a system is quite expensive and room-requiring per se. In addition, a major draw-back is found in the brining process developing a strong salt fog which is unpleasant to work in and which has a highly corrosive effect on the equipment. The brine causes bacteriological problems, the reason why the entire brining plant must be subjected to a cleaning and the brine must be pasteurized or microfiltered at regular intervals.
Attempts have been made at performing the cheese salting by way of injection through needle-shaped pipes inserted in the cheese mass. This method turned out, however, to be unsuited because the structure of the cheese is destroyed by the insertion.
Another attempt at avoiding the complicated brining has been described in U.S. Pat. No. 3,798,340 (Reinbold et al.). According to this publication, porous absorbing materials, such as cellulose sponges, are applied to at least two of the sides of a cheese block inside a closed container, a salt solution being provided in said cellulose sponges. In the closed container, the salt from the sponge can diffuse into the cheese so as to salt said cheese. The method suggested by Reinbold is, however, encumbered with the major draw-back that the introduction of a porous sponge requires taking of extensive precautionary measures in order to avoid a deterioration or destroying of the cheese due to microbiological pollution. In addition, the used porous sponge presents a foreign body which must be removed and disposed of upon use, preferably in an environmentally acceptable manner.
It is a well-known fact that when a highly concentrated salt-containing material is applied to the surface of cheese, said cheese is softened by way of osmosis in the area immediately surrounding the salt applied with the result that the structure and texture of the ready-made cheese product is deteriorated or destroyed.
The latter knowledge is confirmed by the disclosure of the above U.S. Pat. No. 3,798,340 (Reinbold et al.), because the solution suggested by Reinbold implies that some impeding effect is obtained by placing the osmotically active salt-containing material in a sponge in such a manner that the strong osmotic effect is delayed or hampered. The same teaching forms apparently the basis of an embodiment according to said US publication, whereby the salt is used in form of solid salt. By this embodiment, the salt is applied to the side of the sponge facing away from the cheese in such a manner that the sponge provides a delayed migration of the salt into the cheese with the result that the difference in osmotic pressure is reduced across the surface of the cheese. In column 7, line 13-15, Reinbold indicates that it is important to keep the salt in dry form away from a direct contact with the outer surface of the cheese.
Despite the desire of avoiding the complicated brining, none of the above attempts have been successful in convincing persons skilled in the art about the fact that brining can be avoided when it is desired to obtain a cheese of a quality acceptable to the customers with respect to both taste and texture, said attempts probably being unsuccessful due to the above draw-backs.
BRIEF DESCRIPTION OF THE INVENTION
It turned out surprisingly that a cheese can be salted by placing the salt in direct contact with the cheese without using any osmotically impeding or diffusing-delaying material at all in a water-impermeable packing and without destroying the organoleptic properties of the cheese. Thus the present invention relates to a method of salting cheese in a water-impermeable packing by means of a packing material, whereby the desired amount of salt is added in form of a salt-containing solution or dispersion or in form of solid salt directly on one or more of the outer surfaces of the cheese and/or in the packing material, whereafter a water-impermeable packing surrounding the cheese and the salt is provided by means of said packing material.
This method renders it possible to salt a cheese after the shaping thereof without necessitating a performing of the difficult and cost-intensive brining. The following procedure is followed: Initially, the cheese is packed together with the calculated amount of salt which is kept in direct contact with the outer surface of the cheese. Subsequently, the cheese is allowed to stay in the packing until the desired equilibration for the salt concentration is obtained in the water phase of the cheese at the same time as an equilibrium is obtained in the distribution of the water phase in the cheese mass. As a result, the essential advantage is obtained that it is possible to control the salt content in each cheese within narrow tolerances about the optimal value.
By placing the calculated amount of salt directly on one or more of the sides of the cheese in accordance with the invention, such as on the top side and the bottom side, and by packing the cheese with salt applied thereon in a water-impermeable packing, it is possible to obtain a satisfying cheese with the desired texture and with the salt uniformly distributed throughout the entire cheese mass. Such a uniform distribution can be obtained because in practise the aqueous phase of the cheese is a continuous phase with the effect that the salt is uniformly distributed in the cheese within a relatively short period of time in accordance with known chemical and physical principles.
The packing of the cheese in a water-impermeable sheet can in practise be performed by applying the salt according to a predetermined pattern, such as in form of stripes of a salt solution, salt dispersion or dry salt, such as salt particles, onto the sheet before the cheese is placed thereon. Then the cheese is placed on top of the sheet with stripes of salt, and additional stripes of salt are applied to the upper outer surface of the cheese. When the cheese is then immediately wrapped in the water-impermeable sheet, it turned out that said sheet provides a reliable support sufficient for retaining the cheese in the initial softening phase which is developed as a consequence of the contact with the concentrated salt. Once the salt has been uniformly distributed throughout the entire cheese mass, the cheese re-establishes the desired structure also in the portions adjacent the outer surface.
The extent of applicability of the invention appears from the following detailed description. It should, however, be understood that the detailed description and the specific examples are merely included to illustrate the preferred embodiments, and that various alterations and modifications within the scope of protection will be obvious to persons skilled in the art on the basis of the detailed description.
DETAILED DESCRIPTION OF THE INVENTION
The method according to the invention allows applying of for instance salt in dry form, such as salt particles flat salt-containing sheets, plates, tablets, or flat salt blocks, onto one or more of the outer surfaces of the ready-made cheese, whereafter both the cheese and the salt is wrapped in a water-impermeable packing. In practise it turned out, however, often to be advantageous to apply the salt in form of a salt suspension or salt dispersion typically containing 40 to 60% by weight, for instance approximately 50% by weight of salt and 50% by weight of water. Such a dispersion has a mushy consistency and a sufficiently homogeneous composition so as to allow the salt dispersion to the sprayed in the desired amount in form of stripes.
In a further embodiment the salt dispersion can advantageously be a viscous, paste-like salt dispersion typically containing 50 to 80% by weight, such as 60 to 75% by weight of salt. To achieve such a viscous salt dispersion it is usually necessary to add a stabilizer as adjuvant for stabilizing the water phase. Such a stabilizer must, of course, be acceptable for use in articles of food. Particularly advantageous stabilizers are natural ingredients of milk, such as sodium caseinate or whey protein.
Firstly, such viscous, paste-like salt dispersions present an advantageously high content of salt. In addition, they ensure considerable advantages by being easy to handle and accordingly suited for an accurate and uniform distribution on the outer surface of the cheese. Thus, a paste-like salt dispersion may for instance be applied as stripes of strings which do not flow out, but remain on the outer surface of the cheese both before and during the packing procedure.
When the cheese is sufficiently solid, it is also possible to use a salting material containing a relatively low salt concentration, such as in form of an ordinary brine, i.e. a saturated salt solution.
A dosing unit suitable for the above measured spraying of a fluid salt-containing preparation in form of a salt solution or salt dispersion is the dosing unit type NDU, which is sold by APV Pasilac A/S, DK-8600 Silkeborg, Denmark. This dosing unit has already proved suited for dosing salt dispersion in connection with salting of butter.
Any packing material can be used as packing material by the method according to the invention, provided it is acceptable for use in contact with articles of food and provided it is sufficiently water-impermeable. In some cases, the packing material used should be water-impermeable as well gas-permeable when it is to be used for some types of cheese generating much gas, such as emmentaler. Other types of cheese, such as Danbo cheese, generate only insignificant gas, and for such types of cheeses it is possible to use both water-impermeable and gas-impermeable packing materials.
Particularly preferred packings are such made of film or sheet capable of surrounding and fixing the cheese after the packing. Examples of suited packing films are various laminates comprising a layer of polyethylene on the side facing the cheese, and which can be provided with or be without a gas-barrier layer as required. Examples of suitable laminates are for instance the following laminates all sold by Raackmanns Fabriker A/S, Hattingvej 10, DK-8700 Horsens, Denmark:
PA/PVdC/PE, comprising the following layers seen from the outside and inwards towards the cheese: polyamide/polyvinylidene chloride/polyethylene.
PA/PE-E-PE, comprising in the same sequence: polyamide/poly ethylene/ethylene vinylalcohol/polyethylene.
PE-E-PE/PA/PE, comprising in the same sequence: polyethylene/ethylene vinylalcohol/polyethylene/polyamide/polyethylene.
PE/PVdC/PA/PE, comprising in said sequence: polyethylene/polyvinylidene-chloride/polyamide/polyethylene.
PE/PVdC/PA/PVdC/PE comprising in said sequence: polyethylene/polyvinylidene chloride/polyamide/polyvinylidene chloride/polyethylene.
The cheese salted by the method according to the invention is usually present in form of a cheese block resulting from acidification and/or rennet processing of the cheese by way of pressing in a cheese press, where whey is liberated while a pressed cheese block of a suitable solidity is obtained.
The pressed cheese block is typically a block of for instance 10 kg available as a cheese block which can be handled, i.e. moved. The cheese block cannot, however, stand a too violent handling as the surface structure may thereby be damaged.
In many cases the structure of the outer surface of the cheese is so soft that it is important that the feeding of salt, such as in form of dry salt or in form of a salt dispersion, is performed in a careful and lenient manner. Thus, it is not advisable in this case to carry out an actual rubbing of the salt into the outer surface of the cheese.
After the pressing, the cheese block is usually of a temperature of 25°-37° C. Some types of cheese may, however, be of a substantially higher temperature, such as perhaps up to 60° or 70° C. Conventional salting in brine can involve either a cooling down of the cheese block to a temperature of approximately 10° C. usually during approximately 12 hours before the cheese block is transferred to the brine, or a transferring of said cheese block directly into the brine.
Also by the method according to the invention, the salting can be performed after a cooling down of the cheese block to 10° C. It turned out, however, that the feeding of salt and the packing can advantageously be performed immediately upon the pressing of the cheese block, i.e. when the cheese is a few minutes old and still of a temperature of approximately 20°-70° C., typically approximately 25°-37° C.
In addition to saving the costs involved in cooling down to 10° C., it turned out that in this manner a cheese of an improved quality is obtained. The improved quality is assumed to be due to the outer surface not being subjected to a chock-cooling, which can cause a vigorous post-acidification in the outer surface.
When the salt is applied to the outer surface of the cheese, said salt is distributed in the cheese through the water phase. The temperature of the cheese at the salting is here decisive for the speed at which the salt is absorbed. A higher temperature causes a faster absorption of salt. Tests have shown that cheese blocks, treated by the method according to the invention and not cooled prior to the salting and packing, absorbed the salt very quickly. In addition, the surface was dry and fine unlike corresponding cheeses, which had been subjected to a cooling prior to the salting, where the surface was moist. The texture of the cheeses not having been cooled prior to the salting was very satisfactory.
Conventional brining implies that the cheese usually liberates some fluid to the brine. By the method according to the invention this fluid is retained in the packing and reabsorbed in the cheese before the packing is opened. The manufacture of a cheese with a desired dry matter content must, of course, consider the above in such a manner that a pressed cheese block manufactured as starting material is to contain slightly more dry matter than the cheese block to be salted in brine. Such an adjustment of the dry matter content is a routine procedure also being continuously performed today in connection with conventional manufacture of cheese involving brining.
The salting by the method according to the invention has been terminated when the salt has been absorbed in the water phase of the cheese and when the fluid exuded on the outer surface of the cheese has been reabsorbed in the cheese mass. Such a cycle is usually completed in approximately 48 hours, while the packed, salted cheese block is placed in a store room at 10°-12° C. After the salting, the packing can be ripped open and the cheese be ripened in a conventional manner. It is, however, also possible to leave the cheese block in the packing during the entire subsequent ripening period or during the first part thereof.
By the manufacture of conventional rind cheese it is thus possible to keep the wrapped cheese in the packing for approximately 2 weeks at 10°-12° C., whereafter the packing is unwrapped and the ripening is continued in a usual manner at approximately 20° C. while the rind is formed with or without a conventional smearing, i.e. application of a bacteria-containing layer.
For the manufacture of rindless cheese, said cheese is advantageously left in the packing during the entire ripening period. In this case, the ripping open of the packing can be postponed until immediately before the cheese is cut up and packed in the retail packing. The storing of the salted cheese in the impermeable packing during the entire ripening period makes it extremely easy to handle the cheese during the ripening period. As the cutting up and packing in retail packings are often carried out another place than the place of the manufacture and the ripening of the cheese, particular advantages are provided in connection with the delivery as the cheese is already placed in a protecting packing after the salting step.
As mentioned, the ripening is usually carried out in cheese blocks of for instance 10 kg. It is, however, also possible to ripen the cheese in form of small blocks. In this case it is possible to salt and wrap the pressed and optionally cut out small cheese blocks and to use the packing as the ready retail packing.
It turned out surprisingly that the structure of the cheese is not destroyed by the salting method according to the invention. The latter feature can be attributed to the fact that the packing supports the cheese throughout a critical phase where the cheese presents a very soft outer surface. In practise, the method has been tested in connection with packing in a plastic film, but it is expected that it can also be performed in connection with another type of packing, such as for instance a close-fitting cylindrical container. The latter container is preferably made of a material which is easy to clean, such as metal, plastics or glass.
In addition, it is found to be important that the packing is so close-fitting that the fluid being liberated from the outer surface of the cheese during the salting is always kept in close contact with said outer surface.
EXAMPLE 1
The following tests were performed in order to substantiate the carrying out of the method according to the invention and in order to confirm the result expected.
Two cheesings were performed in 150 l cheese vats with cheese of the type Havarti, whereby 6 pieces of cheese of 4 kg/piece were produced.
The six cheeses were subsequently pressed by a pressure of 3 bar (300 kPa) for 90 minutes, whereafter they were removed from the moulds.
The ready-pressed cheeses were placed in a water bath of corporation water for approximately 12 hours so as to be cooled down and achieve a form stability and a completed acidification.
One cheese from each of the two cheesings was halved into approximately 2 kg/pieces and sprayed with natamycine to inhibit mould growth.
All four cheeses of 2 kg/piece were weighed and placed in their respective weldable, water-impermeable bag together with 2% by weight of dry salt. Each bag was turned upside down and around manually until the salt had been distributed on all surfaces of the cheese and the bag. Then the bags were vacuum-sealed. The cheeses packed in bags were stored at 14° C. for 4 weeks with a turning upside down twice a week.
The remaining 4 cheeses were conventionally brined and ripened under the same conditions as the cheeses wrapped in bags.
After ripening for 4 weeks, the cheeses wrapped in bags and the conventionally brined cheeses were analysed and evaluated:
______________________________________ Salting in bag Cheese BriningAnalysis Cheese vat 1 vat 2 Cheese vat 1______________________________________Dry matter % by weight 53.90 52.62 53.25pH 5.37 5.46 5.26Salt % by weight 2.06 1.96 2.26Fat % by weight 25.04 25.03 25.23Fat in dry matter % by 46.5 47.6 47.4weightWater in fat-free cheese % 61.5 63.2 62.5by weight______________________________________
Organoleptic evaluation
A panel of 3 experienced persons participated.
A comparison was made between the conventionally brined cheeses and the bag-salted cheeses. Compared vat by vat, no difference was observed between the various cheeses with respect to odour, taste, and texture.
The conclusion of the tests performed is that the method according to the invention is viable on an industrial scale.
EXAMPLE 2
The present Example describes the manufacture of a viscous salt dispersion by means of whey protein concentrate as stabilizer.
A 75% by weight of paste-like salt dispersion was prepared in the following manner:
3 g of powdered whey protein concentrate (LACPRODAN 80, delivered by Danmark Protein, N.o slashed.rre Vium, Videb.ae butted.k, Denmark) are added to 17 g water. Then the water phase is stabilized by way of heating until the phase has become sufficiently viscous, usually at 80° C., whereafter a cooling is immediately carried out to 10°-20° C. Then 60 g of salt are admixed under stirring, said salt being of a particle size where 94% are in the range 125-600 μm. In this manner a very viscous highly concentrated paste-like salt dispersion is obtained. This salt dispersion is of such a texture that it can be pressed out, such as through a nozzle, and directly onto the outer surface of the cheese in form of stripes or in another pattern, such as for instance small tops. After the packing of a cheese salted with this whey protein-containing salt dispersion, the whey protein is absorbed and homogeneously distributed in the cheese in the same manner as the salt.
In the same manner a less viscous, but still suitable salt dispersion containing 60% by weight of salt is prepared from 6 g LACPRODAN 80, 36 g water and 60 g salt.
EXAMPLE 3
The present Example uses sodium caseinate (MIPRODAN, delivered by MD Foods, Viby, Denmark) as stabilizer. A viscous salt dispersion of the same type as described in Example 2 is prepared by means of a sodium caseinate-stabilized water phase containing 10% by weight of sodium caseinate. The water phase is stabilized by way of heating and a subsequent cooling as described in Example 2, whereafter it is mixed with salt in a weight ratio of 40:60 and 25:75. Also the sodium caseinate is absorbed and homogeneously distributed in the cheese during the salting.
The above description of the invention reveals that it is obvious that it can be varied in many ways. Such variations are not to be considered a deviation from the scope of the invention, and all such modifications which are obvious to persons skilled in the art are also to be considered comprised by the scope of the succeeding claims. | A method of salting a cheese in a water-impermeable packing, where the desired amount of salt is applied on one or more of the outer surfaces of the cheese and/or in the used packing material, whereafter a water-impermeable packing is provided by means of said packing material, said packing surround the cheese and the salt. The method renders it possible to avoid the complicated and cost-intensive brining in brine and to control the content of salt to an optimal degree. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No. 09/732,291, filed Dec. 8, 2000, which is related to U.S. application Ser. No. 09/732,292, filed on the same date, which is a continuation of U.S. application Ser. No. 09/265,363, filed Mar. 10, 1999, which is a continuation of U.S. application Ser. No. 08/833,346, filed Apr. 4, 1997, now U.S. Pat. No. 5,887,147, issued Mar. 23, 1999, which is a continuation of U.S. application Ser. No. 08/598,903, filed Feb. 9, 1996, now U.S. Pat. No. 5,652,845, issued Jul. 29, 1997, which is a continuation of U.S. application Ser. No. 08/190,848, filed Feb. 3, 1994, now abandoned, the subject matter of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an information output system or display apparatus including a computer and an information output device such as a display device or a printer as a computer terminal and more particularly to an information output system or display apparatus for performing various types of control such as the information output method and allowing or not allowing of information output from the computer connected to the above information output device via a communication interface.
[0003] In current display devices as computer terminals, a wide variety of display positions and sizes on the screen and video signal frequencies to be displayed are used depending on video signals to be inputted. Therefore, a display or a so-called multi-scan display has been used so that a display device can handle various video signals.
[0004] A microcomputer or a memory LSI is used to provide a most suitable display image for each video signal as this type of display device. Such a prior art is indicated in Japanese Patent Application Laid-Open No. 1-321475.
[0005] According to this prior art, the microcomputer controls the memory which stores information of the display position and size on the screen for each video signal beforehand and reads the information of the most suitable display position and size on the screen depending on the input video signal from the memory. The microcomputer outputs a control signal on the basis of the read information. This control signal is applied to the deflection circuit as a control voltage or control current through a D-A converter so as to control the voltage or current at a predetermined part of the deflection circuit. By doing this, the display size and position of the display device can be adjusted. When a video signal inputted to the display device is not a known signal, no corresponding information is kept in the above memory. Therefore, the switch mounted on the front of the display device is operated so as to input the adjustment information of the display position and size on the screen. The control circuit of the above microcomputer creates deflection control information on the basis of the above input information and adjusts the display position and size.
[0006] According to the aforementioned prior art, the display device obtains a most suitable screen display according to the input video signal. However, according to another prior art, the computer controls and changes the display status. Such a prior art is indicated in Japanese Patent Application Laid-Open No. 61-84688. According to this prior art, a discrimination pulse is superimposed at the blanking interval of a video signal outputted from the computer and the deflection frequency of the display device is changed on the basis of this discrimination pulse.
[0007] According to the former prior art among the aforementioned prior arts, the control of the display position and size on the screen is managed by the display device. Therefore, when adjustment is required or requested from the user of display device, it is necessary to perform manual adjustment using the adjustment switch of the display device each time and it is rather troublesome to operate the system.
[0008] According to the latter prior art among the aforementioned prior arts, the control can be operated by the computer. However, since the operation is such that the deflection frequency is simply changed on the basis of the discrimination pulse superimposed on the video signal, an image cannot be adjusted to the display image (display position and size) which is required by a user of the computer. Namely, there is a problem imposed that the status which is simply desired by the user cannot be obtained. Furthermore, no consideration is given to prevention of display (indication) of careless images (information) and restraining of unnecessary power consumption. Even if the discrimination pulse is superimposed at the blanking interval of the video signal, the video blanking level is generally shallow in the case of the display device, so that the discrimination pulse is displayed. Furthermore, the control is applied only in one direction from the computer to the display device and no information is sent in the reverse direction, so that there is another problem imposed that a malfunction cannot be avoided.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide an information output system wherein a computer can exercise various types of control of an information output device such as a display device. Another object of the present invention is to provide an information output system for maintaining secrecy of information and for restraining power consumption. A further object of the present invention is to provide an information output system for informing the computer of the operation status of the information output device so as to allow easy maintenance.
[0010] To accomplish the above objects, according to the present invention, in an information output system consisting of at least a computer and an information output device, the computer is equipped with a first communication means and the information output device is equipped with a second communication means. Furthermore, a control processing means and a memory means for storing the identification number of the computer beforehand are added to the information output device, or a memory means for storing the identification number of the information output device beforehand is mounted in the computer in addition to the first communication means. The above second communication means has a plurality of communication interfaces. Furthermore, a detection means for detecting the internal operation status and a control processing means for judging the detection result are added to the information output device and an audio output means for outputting the operation status in voice is added to the computer. A second display means for displaying the operation status is mounted in the information output device. Or, a display means for displaying the operation status of the information output device is mounted in the computer.
[0011] The first communication means in the computer controls communication with the information output device and the second communication means in the information output device controls communication with the computer. The control processing means operates and generates control signals for exercising various types of control for the information output device on the basis of control instructions from the second communication means and compares the identification number of the computer stored in the memory means with the identification number sent from the computer via the first and second communication means. When a comparison result match occurs, the control processing means controls a predetermined part in the information output device.
[0012] Tn the memory means mounted in the computer, the identification number for identifying the information output device is stored beforehand. When the identification number which is sent from the information output device via the second and first communication means matches with the identification number which is stored in the memory means beforehand, the computer communicates with the information output device.
[0013] When no comparison result match occurs, the above control processing means controls so that information which is sent from the computer to the information output device is not normally outputted from the information output device. By doing this, information of a computer user will not be indicated carelessly.
[0014] When the second communication means has a plurality of communication interfaces, it can communicate with another plurality of information output devices and the computer and in the state that a plurality of similar information output devices are connected to the computer, it can exercise various types of control for the information output devices and can inform the computer of the status of each information output device.
[0015] The detection means detects the internal operation status of the information output device and the control processing means judges the detection result. The audio output means indicates the operation status of the information output device in voice on the basis of the judgment result which is sent from the information output device to the computer via the second and first communication means. Furthermore, the display means mounted in the information output device displays the above operation status. The display means mounted in the computer performs the same operation as that of the display means mounted in the information output device. In this case, information which is sent to the computer via the second and first communication means is used as display information.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a block diagram showing the first embodiment of the present invention.
[0017] [0017]FIG. 2 is a memory map showing the contents of the memory in the display device shown in FIG. 1.
[0018] [0018]FIG. 3 is a flow chart showing the operation of the essential section shown in FIG. 1.
[0019] [0019]FIG. 4 is a block diagram showing the second embodiment of the present invention.
[0020] [0020]FIG. 5 is a block diagram showing the third embodiment of the present invention.
[0021] [0021]FIG. 6 is a block diagram showing the internal structure of the display device 6 B shown in FIG. 5.
[0022] [0022]FIG. 7 is a block diagram showing the fourth embodiment of the present invention.
[0023] [0023]FIG. 8 is a flow chart showing the operation outline shown in FIG. 7.
[0024] [0024]FIG. 9 is a block diagram showing the fifth embodiment of the present invention.
[0025] [0025]FIG. 10 is a block diagram showing the sixth embodiment of the present invention.
[0026] [0026]FIG. 11 is a block diagram showing the seventh embodiment of the present invention.
[0027] [0027]FIG. 12 is a block diagram showing the eighth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The embodiments of the present invention will be explained with reference to the accompanying drawings hereunder.
[0029] [0029]FIG. 1 is a block diagram showing the first embodiment of the present invention. In the drawing, a section 1 enclosed by a chained line indicates a computer. In the section 1 , a reference numeral 2 indicates a CPU (central processing unit), 3 a display controller for generating various signals for video display, 4 a memory, and 5 a communication controller for communicating with peripheral devices. In addition, a magnetic recording unit is mounted as a data storage device which is not shown in the drawing.
[0030] A section 6 enclosed by another chained line indicates a so-called multi-scan display device which can be applied to various video signal specifications. In the section 6 , a reference numeral 7 indicates a microcomputer for controlling display of the display device 6 , 8 a second communication controller for communicating with the above communication controller 5 , 9 a second memory, 10 a general deflection circuit of the display device, 11 a video circuit of the display device, 12 a horizontal deflection yoke, 13 a vertical deflection yoke, and 14 a color cathode-ray tube (hereinafter called a CDT (color display tube)) for displaying color images.
[0031] The operation shown in FIG. 1 is as shown below. The computer 1 has a structure which is the same as the general structure of a conventional personal computer or work station and the communication controller 5 controls a communication interface such as RS-232C which is installed in the standard type. When a control instruction of the display device 6 is inputted firstly by a user of the computer from a general keyboard which is not shown in the drawing of the computer 1 , it is coded digitally by a keyboard controller which is neither shown in the drawing and CPU 2 identifies the instruction and controls the communication controller 5 . The communication controller 5 sends the control instruction of the display device to the display device 6 . When a control instruction of the display device 6 which is included in the software for allowing the computer 1 to operate is read from the external storage device such as a floppy disk drive or hard disk drive which is not shown in the drawing, CPU 2 identifies the instruction and controls the communication controller 5 . The communication controller 5 also sends the control instruction of the display device to the display device 6 .
[0032] Next, the display device 6 sends the control instruction from the computer 1 which is received by the communication controller 8 to the microcomputer 7 . The microcomputer 7 identifies this control instruction and generates control signals to the relevant portions to be adjusted in the deflection circuit 10 or video circuit 11 . The aforementioned deflection circuit 10 and video circuit 11 can be adjusted in the same way as with a conventional multiscan display and the adjustment means has a structure which is the same as that of a conventional multiscan display. By doing this, the display size and position, brightness, contrast, and hue of images displayed on the CDT 14 are made most suitable to a user of the computer system.
[0033] Furthermore, WYSIWYG (what you see is what you get) control which makes an image displayed on the display device 6 similar to print output of an output device other than the display, for example, a printer can be realized only by sending a control instruction for changing the display position and size to the display device 6 instead of operating and generating display data by the computer 1 . The interface part of the above display device 6 such as the communication control terminal is mounted on the back or side of the display device from a viewpoint of easy connection to the computer 1 and appearance.
[0034] Furthermore, the aforementioned communication function is used for adjustment at a factory. In this case, necessary information is all written into the memory 9 in the display device 6 . FIG. 2 is a memory map showing the contents of the memory 9 in the display device 6 . For adjustment at factory, data to be written can be all set. In a case other than factory adjustment, namely, for adjustment in a system as shown in FIG. 1, to prevent data requiring no rewriting, namely, preset values at factory such as, for example, the number of all data or the data within the corresponding frequency range from being erased by mistake or rewritten, the computer 1 sends the ID number and the microcomputer 7 in the display device 6 checks the ID number with the registered ID number stored in the memory 9 .
[0035] A flow chart of this check is shown in FIG. 3. As shown in the drawing, when the computer 1 and display device 6 are turned on at Step 1 , each device is initialized at Step 2 . Concretely, CPU 2 and the microcomputer 7 read the starting system software and put the peripheral circuit to be connected to the CPU into the active state so that the next operation can be performed. Then, at Step 3 , the microcomputer 7 in the display device 6 waits for sending of the identification number assigned to the computer 1 , that is, the so-called ID number from the computer 1 . Next, at Step 4 , the microcomputer 7 receives the ID number which is sent from the computer 1 and checks whether the received ID number is registered in the registered ID number list which is stored in the memory 9 in the display device 6 .
[0036] When it is registered, at Step 5 , the computer 1 is allowed to control the display device 6 by external control instructions so that the user control of the display size, position, brightness, and contrast can be performed by control instructions sent from the computer 1 thereafter. On the other hand, when the received ID number is not registered in the memory 9 , at Step 6 , the display device 6 is not allowed to be controlled by external control instructions thereafter. Therefore, even if any control instruction is sent from the computer 1 , the display device 6 will not accept it.
[0037] Or, at Step 5 , the computer 1 may be allowed to perform all the adjustments which can be performed by the display device 6 , that is, the same control as that for adjustment at factory and at Step 6 , a part of the control of the display device 6 such as display control may be allowed.
[0038] By doing this, the display device 6 can be prevented from careless control.
[0039] The above is an example that an ID number is sent to the display device 6 from the computer 1 . However, needless to say, the reverse case of the above is possible. Namely, an ID number is sent to the computer 1 from the display device 6 so that the computer 1 identifies that the display device 6 having a communication function is connected and the computer 1 compares the ID number with the ID number registered in the computer 1 . When the corresponding ID number is registered, the computer 1 controls the display device 6 by a predetermined control instruction. When it is not registered, the computer 1 judges that it cannot control the display device 6 and will not control the display device 6 .
[0040] By doing this, the computer 1 communicates with a specific display device 6 and can exercise control such as changing the color temperature of an image displayed on the display device 6 or changing the display size depending on the application software.
[0041] According to this embodiment, RS-232C is used as a communication interface. However, a general-purpose interface such as RS-422, RS-423, SCSI or GP-IB, or network interface may be used. Furthermore, the embodiment may be applied to an interface using optical signals instead of electric signals. The above interface may be installed in the neighborhood of the rear cabinet or lower pedestal of the display device 6 for convenience of a user.
[0042] [0042]FIG. 4 is a block diagram showing the second embodiment of the present invention. According to this embodiment, when the ID number sent from the computer to the display device is not registered in the memory 9 , another operation which is different from the operation shown in the first embodiment is performed. Namely, according to this embodiment, when the ID numbers do not match with each other, nothing is displayed on the display device so as to enhance the secrecy of information.
[0043] Next, the structure of FIG. 4 will be explained. In the drawing, a reference numeral 6 A indicates another display device which is different from the display device 6 shown in FIG. 1, 15 a horizontal deflection circuit, 16 a vertical deflection circuit, 17 a synchronizing signal processing circuit, 18 a horizontal phase control circuit, 19 a horizontal oscillating circuit, 20 a horizontal driving circuit, 21 a horizontal deflection output circuit, 22 a video pre-amplifier circuit, 23 a video blanking circuit, and 24 a video output circuit. The other reference numerals which are the same as those shown in FIG. 1 indicate the same functions. The video circuit 11 is a general video circuit consisting of the video pre-amplifier circuit 22 , video blanking circuit 23 , and video output circuit 24 . The horizontal deflection circuit 15 is a general deflection circuit consisting of the synchronizing signal processing circuit 17 , horizontal phase control circuit 18 , horizontal oscillating circuit 19 , horizontal driving circuit 20 , and horizontal deflection output circuit 21 . The vertical deflection circuit 16 is also a general circuit which has a structure similar to that of the horizontal deflection circuit 15 .
[0044] Next, the operation shown in FIG. 4 will be explained. In the drawing, an ID number sent from the computer 1 is inputted into the microcomputer 7 via the communication controller 8 . The microcomputer 7 checks the above ID number with the ID number stored in the memory 9 . When the ID number stored in the memory 9 matches with the ID number sent from the computer 1 , the microcomputer 7 receives the control from the computer 1 .
[0045] On the other hand, when the check results do not match with each other, the microcomputer 7 controls the horizontal oscillating circuit 19 , fixes the oscillation frequency to a predetermined value, and allows the display device 6 A to perform a horizontal deflection operation at a value different from the horizontal frequencies of the video signal and synchronizing signal which are sent from the computer. Therefore, the image displayed on the CDT 14 is not synchronized horizontally in this case and the screen content cannot be judged. When the vertical deflection circuit 16 is controlled in the same way, the image displayed on the CDT 14 is not synchronized vertically on the screen. By controlling the video blanking circuit 23 of the video circuit 11 , the video display period may be blanked so that no image is displayed on the CDT 14 .
[0046] By using the aforementioned methods independently or combined, only when a user of the computer system enters a predetermined ID number from the keyboard, it is displayed correctly on the display device 6 A and information displayed on the CDT 14 can be prevented from careless indication.
[0047] [0047]FIG. 5 is a block diagram of the third embodiment of the present invention. According to this embodiment, the display device is provided with a plurality of communication functions and a plurality of display devices can be connected with the communication interface. In the drawing, reference numerals 6 B, 6 C, and 6 D indicate display devices having the same structure, V 1 , V 2 , and V 3 lines for video signals and synchronizing signals, C 1 , C 2 , and C 3 communication lines for, for example, RS-232C, and 1 the aforementioned computer. Each of the display devices 6 B, 6 C, and 6 D has a plurality of video signal I/O terminals and communication interface I/O terminals and a registered ID number. According to this embodiment, as shown in FIG. 5, 1 is assigned to the display device 6 B as an ID number, 2 to the display device 6 C as an ID number, and 3 to the display device 6 D as an ID number.
[0048] Next, the operation shown in FIG. 5 will be explained. In the drawing, for example, when controlling the display device 6 B from the computer 1 , the ID number 1 is sent to the line C 1 and the display device 6 B is controlled appropriately from the computer 1 . Next, when controlling the display device 6 C, the ID number 2 is sent from the computer 1 in the same way. Then, the ID number is received by the display device 6 C via the lines C 1 and C 2 and the display device 6 c can be controlled appropriately from the computer 1 .
[0049] Since a plurality of display devices can be controlled by a computer in this way, a plurality of display devices can be adjusted at a time, for example, at the time of delivery adjustment at a factory. Furthermore, by using a multi-display system for displaying an image by assembling a plurality of display devices and for displaying various images on each screen, the display devices can be hued and adjusted in brightness simply.
[0050] [0050]FIG. 6 is a block diagram showing the internal structure of the display device 6 B shown in FIG. 5. In the drawing, a reference numeral 25 indicates a communication controller having two communication ports and 26 a divider of video signals and synchronizing signals. The communication controller 25 sends or receives data to or from the computer 1 in the same way as the communication controller 8 of the display device 6 shown in FIG. 1 and also divides the communication lines and relays other display devices. On the other hand, the divider 26 divides video signals or synchronizing signals sent from the computer 1 or signal source to other display devices. By using such a structure, a plurality of display devices can be connected to a computer as shown in FIG. 5.
[0051] Next, the fourth embodiment of the present invention will be described. FIG. 7 is a block diagram showing the fourth embodiment of the present invention. In the drawing, a reference numeral 1 B indicates a computer, 31 an audio control circuit for producing a sound, 32 a speaker, 6 E a display device, 27 and 28 analog-digital converters (hereinafter abbreviated to ADC), and 29 and 30 digital-analog converters (hereinafter abbreviated to DAC). The other reference numerals which are the same as those shown in FIG. 1 indicate the same functions. The operation of FIG. 7 will be explained hereunder with reference to the operation flow chart shown in FIG. 8.
[0052] When the computer 1 B and display device 6 E are started at Step 10 as shown in FIG. 8, they start communication with each other via the communication controllers 5 and 8 at Step 11 next. Then, at Step 12 , the computer 1 B calls the display device 6 E. When no response is received, the computer 1 B judges that the display device 6 E is faulty, starts the audio control circuit 31 at Step 13 , and informs the user of the computer 1 B that the display device 6 E is faulty from the speaker.
[0053] When the communication succeeds, at Step 14 , the microcomputer 7 fetches information of the operation status of the deflection circuit 10 or video circuit 11 in the display device 6 E from the voltage at a predetermined part in the circuit as digital information via the ADCs 27 and 28 . Next, at Step 15 , the microcomputer 7 judges whether the value which is fetched at Step 14 is a value in the normal operation status. When the microcomputer 7 judges it as an error, it informs the computer 1 B of the faulty value via the communication controller 8 and CPU 2 of the computer 1 B allows the audio control circuit 31 to operate and generates a message informing an error of the display device 6 E from the speaker 32 . Furthermore, CPU 2 allows the display controller 3 to operate and displays also a message informing an error on the CDT 14 via the video circuit 11 .
[0054] In this case, when an indication code informing the faulty part is sent to the computer 1 B from the display device 6 E simultaneously, the computer 1 B judges the indication code and can inform the user or a customer engineer of the display device 6 E of the faulty part by sound or display.
[0055] When the display device 6 E is normal at Step 15 , the computer 1 B can exercise the communication control such as the display size, hue, and brightness of the display device 6 E at Step 17 . At this step, when a control instruction is sent to the display device 6 E from the computer 1 B, the microcomputer 7 decodes the instruction and outputs the control code to the corresponding DAC 29 or 30 . The DAC 29 or 30 controls a predetermined control part at the DC control voltage corresponding to the above control code and controls the display size, position, and hue of the image displayed on the CDT 14 . When the above series of operations ends, the computer 1 B returns to Step 14 and repeats the operations from the monitor mode of a faulty operation of the display device 6 E to the normal operation at Step 17 .
[0056] As mentioned above, the computer 1 B can be informed of a faulty operation by using the communication function of the display device 6 E. Therefore, the user can judge the faulty part and can maintain the system easily.
[0057] [0057]FIG. 9 is a block diagram showing the fifth embodiment of the present invention. This embodiment obtains the same effect as that of the embodiment shown in FIG. 7. In FIG. 9, a reference numeral 6 F indicates a display device, 33 a liquid crystal display controller in the display device 6 F, and 34 a liquid crystal display panel mounted in the display device 6 F. The other reference numerals which are the same as those shown in FIGS. 1 and 7 indicate the same functions.
[0058] The operation shown in FIG. 9 is basically the same as that shown in FIG. 7. The operation of the deflection circuit 10 or video circuit 11 is monitored by the microcomputer 7 via the ADC 27 or 28 . When an error occurs, the microcomputer 7 transmits an indication code informing the occurrence of an error to the computer 1 B via the communication line and informs the user of it by voice from the speaker 32 .
[0059] Furthermore, the microcomputer 7 allows the liquid crystal display controller 33 in the display device 6 F to operate and displays information of the occurrence of the fault and faulty part on the liquid crystal display panel 34 . By doing this, information when an error occurs in the display device 6 F can be obtained more surely.
[0060] [0060]FIG. 10 is a block diagram showing the sixth embodiment of the present invention. This embodiment obtains the same effect as that of the embodiment shown in FIG. 9. In FIG. 10, a reference numeral 1 C indicates a computer and 35 a liquid crystal display controller in the computer 1 C. The other reference numerals which are the same as those shown in FIGS. 1 and 9 indicate the same functions. In FIG. 10, the display function for a fault and faulty operation of the display device shown in FIG. 9 is mounted in the computer lC.
[0061] Namely, when an error occurs in the internal circuit of the display device 6 E, the voltage detected by the ADC 27 or 28 is digitized and processed by the microcomputer 7 as faulty voltage occurrence information and information informing an error is transmitted to the computer 1 C via the communication controller 8 . In the computer 1 C, CPU 2 decodes the transmitted faulty information. When CPU 2 identifies the faulty part of the display device 6 E, it allows the audio control circuit 31 to operate as an audio signal and informs the user of the fault by an audio message from the speaker 32 on one hand. On the other hand, CPU 2 controls the liquid crystal display controller 35 so as to display characters or graphics on the liquid crystal display panel 34 . By doing this, the user of the display device 6 E can be informed of an error or fault of the display device 6 E and can maintain the system easily.
[0062] [0062]FIG. 11 is a block diagram showing the seventh embodiment of the present invention. In the drawing, a reference numeral 36 indicates a power supply of the deflection circuit 10 and video circuit 11 . The other reference numerals which are the same as those shown in FIG. 1 indicate the same functions.
[0063] Next, the operation shown in FIG. 11 will be explained. In FIG. 11, when a control instruction to the display device 6 is issued from CPU 2 of the computer 1 , the communication controller 5 changes the control instruction to a one in the signal format suited to communication and sends it to the display device 6 . The display device 6 returns the signal received by the communication controller 8 to the control instruction which can be identified by the microcomputer 7 and sends it to the microcomputer 7 . The microcomputer 7 judges the control instruction and decides the part of a predetermined section in the display device 6 to be controlled.
[0064] When the control instruction relates to control of the power supply 36 and is an instruction for stopping power supply from the power supply 36 to the deflection circuit 10 , or video circuit 11 , or both circuits, the microcomputer 7 controls the power supply 36 so as to stop the above power supply. Therefore, the image display on the CDT 14 is also stopped.
[0065] By doing this, for example, when the computer 1 is not in operation for a predetermined period, the operation power supply for the display device 6 can be automatically put into the off state. Therefore, unnecessary power consumption can be restrained and the life span of the display device can be lengthened. The aforementioned is power supply off control. However, needless to say, power supply on control is also possible. Namely, in this case, when the computer 1 is turned on or the computer 1 is changed from the function stop state to the active state, the microcomputer 7 , power supply 36 , deflection circuit 10 , and video circuit 11 perform the reverse operation of the aforementioned so that the display device automatically starts to display.
[0066] [0066]FIG. 12 is a block diagram showing the eighth embodiment of the present invention. In the drawing, a reference numeral 37 indicates a display controller and the other numerals which are the same as those shown in FIG. 1 indicate units performing the same functions as those shown in FIG. 1.
[0067] Next, the operation of FIG. 12 will be explained. In FIG. 12, video information is sent to the display device 6 from the communication controller 5 in addition to a control instruction of the display device 6 which is explained in the embodiment shown in FIG. 1. This video information is a digital signal in the same way as a signal which is inputted to the display controller 3 in the embodiment shown in FIG. 1. The communication controller 8 of the display device 6 sends video information among the received signals to the display controller 37 . The display controller 37 performs an operation which is the same as that of the display controller shown in FIG. 1 and generates a video signal to be inputted to a general display. By doing this, also in the embodiment shown in FIG. 12, an effect which is the same as that shown in FIG. 1 can be obtained. Furthermore, in FIG. 12, since video information is transmitted via a communication interface which is connected between the computer 1 and display device 6 , a video signal line which is conventionally necessary is not necessary.
[0068] According to the present invention, a user of a computer can exercise various types of control for an information output device such as a display device from the keyboard of the computer or by the software incorporated in the computer. Therefore, the operability of the computer system is improved so that the system can be used easily and the user can obtain a desired information output status easily.
[0069] When an identification number is set to each device, a value which is set by the above control will not be lost by a careless operation of a user. By setting an identification number for a specific user, the secret of information can be protected inversely. Since the power supply for the information output device can be controlled by the computer when necessary, unnecessary power consumption can be restrained.
[0070] Since the status of the information output device can be monitored simply, the system can be protected against a malfunction and maintained easily. Furthermore, the aforementioned control hardware can be realized in a minimum structure. | A display unit having a processor adapted to control display of the display unit and a communication controller capable of bi-directionally communicating with a video source. The communication controller communicates information received from the video source to the processor. | 6 |
[0001] This invention relates to a method for the treatment of crude oil from a well. The arrangement as described hereinafter provides a mechanical pre-heating system for production crude between the wellhead and the production tank or a system providing crude oil processing prior to pipe line transportation.
BACKGROUND OF THE INVENTION
[0002] Heavy crude oil produced from a well contains the crude oil which is generally highly viscous due to its low temperature, water and particulates of sand. It is necessary to separate out these materials and for this purpose the production material from the well is often pumped into a tank, which is in many cases located adjacent the well head, where the materials are allowed to settle so that the particulates deposit in a layer at the bottom of the tank and above the particulates collects a layer of the water and above the water collects the crude oil. In order to accelerate the settlement, bearing in mind the high viscosity of the crude oil, heat is generally applied to the production tank so as to raise the temperature of the materials within the tank to a predetermined temperature lower than the boiling point of the water. This heating is effected by a pipe inserted into the tank into which heat is injected. One example of a heating system is shown in published PCT application WO 02/084195 of Lange published Oct. 24, 2002, the disclosure of which is co-incorporated herein by reference.
[0003] For safety reasons it is required that the production tank is located 75 feet away from the well head so that a line extends horizontally from the well head to the tank and introduces the mixed materials from the well head into the tank at a position at a height on the wall on the tank. The pressure from the well therefore must also supply the necessary pressure for forcing the viscous materials through the pipe from the well head to the tank.
[0004] In some cases processing chemicals are injected into the pipe at or adjacent the well head so as to be mixed in with the production materials as they are transferred along the pipe to the production tank.
[0005] In other cases the product is transported from the well head to a transfer pipe line which transfers it to a remote location for collection and/or treatment. Thus the product is merely collected and pumped through the pipe over a limited distance to a remote location. The pipe line can be of small diameter such as two inches for transfer over a limited distance of up to two miles.
[0006] The following problems are commonly encountered by heavy oil producers using the above technology today:
1. High flow line pressure from the wellhead to the production tank or transfer pipe caused by the heavy cold production fluids. 2. Increased flow line pressure which reduces oil production and efficiency of the down hole pump. 3. Adequate heat from wellhead to storage tank for (gas and oil flows) is not available other than wellhead engine glycol or exhaust, if there is a wellhead engine. 4. The cooling effect that the required 75 feet of exposed flow line has on the production crude, insulated or not, especially in winter. 5. The convection currents created in the production tanks to current hard firing immersion tube heaters due to the large temperature changes which are necessary from the inlet temperature to the processing temperature. These convection currents impact the ability of solids to settle and to achieve clean oil. 6. The ineffective introduction of treatment chemicals into the flow line. The crude is cold. foamy and solids laden. The current flow line offers no method of chemical distribution in product and no method of de-sanding or ensuring full flow capability.
SUMMARY OF THE INVENTION
[0013] It is one object of the present invention therefore to provide an improved method of treating crude oil.
[0014] According to one aspect of the invention there is provided a method of crude oil production comprising:
producing at a well head a mixture of particulates, crude oil and water; storing the mixture in a production tank for settlement of the mixture in to the constituent parts for separate extraction from the tank; transferring the mixture from the well head to the production tank through a transfer duct; and while transferring the mixture, commencing an initial separation of the mixture.
[0019] Preferably heat is applied to the mixture as it is transferred.
[0020] Preferably the heat is applied by a jacket surrounding a pipe through which the material passes.
[0021] Preferably the pipe is of increased diameter to increase dwell time.
[0022] Preferably the pipe is at least 12 inches in diameter.
[0023] Preferably the pipe contains an auger flight.
[0024] Preferably the auger flight is rotated in a direction to move the particulate materials in a direction toward the tank so as to move the particulate materials to a discharge at or within the tank.
[0025] Preferably the auger flight has a variable pitch.
[0026] Preferably the auger flight has at least a section with a ribbon flight.
[0027] Preferably the transfer duct is divided into at least two paths at its end at the tank for feeding a lighter section including the crude oil through an upper path and a heavier section including the water through a lower path.
[0028] Preferably the upper path includes a heat exchanger for receiving heat from the stack gases of the heater.
[0029] Preferably the transfer duct includes a gas vent which is located at the tank so that gases are released from the stream above the liquid level to avoid discharging bubbles into the liquid which can cause circulating currents which can interfere with the settlement within the production tank.
[0030] According to a second aspect of the invention there is provided a method of crude oil production comprising:
producing at a well head a mixture of particulates, crude oil and water; storing the mixture in a production tank for settlement of the mixture in to the constituent parts for separate extraction from the tank; transferring the mixture from the well head to the production tank through a transfer duct; and while transferring the mixture in the duct, heating the mixture.
[0035] Preferably heat is applied to the mixture in the duct sufficiently to avoid the requirement for heating in the tank.
[0036] Preferably material from the tank is circulated through the duct and back to the tank to avoid the requirement for heating in the tank.
[0037] According to a third aspect of the invention there is provided a method of crude oil production comprising:
providing a mixture of particulates, crude oil and water; transferring the mixture through a transfer duct; while transferring the mixture in the duct, heating the mixture; and providing an auger flight in the duct operable to carry the particulate materials to one end of the duct for discharge, while the crude oil and water flow along the duct.
[0042] In one arrangement, the transfer duct transfers the mixture to a pump and a pipe line for transferring the mixture to a remote location.
[0043] In this arrangement preferably the particulate material is discharged from the transfer duct prior to the pump.
[0044] In this arrangement preferably the auger flight is arranged to form a plug of the particulate material, a part of which is periodically released by a valve
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Embodiments of the invention will now be described in conjunction with the accompanying drawings, in which:
[0046] FIG. 1 is a schematic view of a well head crude oil production system according to the present invention.
[0047] FIG. 2 is a side elevational view of a well head crude oil production system of FIG. 1 .
[0048] FIG. 3 is an end elevational view of the embodiment of FIG. 1 .
[0049] FIG. 4 is a side elevational view of the production system according to the present invention.
[0050] FIG. 5 is a top plan view of the production system according to the present invention.
[0051] In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0052] In FIG. 1 is shown schematically an oil production system including a well 10 which provides oil production at a well head 11 for supply through a pipe 12 to a production tank 13 . The tank is arranged to receive the materials in which settling occurs to provide a layer of particulate material at the base of the tank, a layer of water on top of the sand and the required oil in a layer at the top of the tank.
[0053] The conventional system is modified by the addition of an initial production treating system generally indicated at 20 which includes a duct 21 containing an auger flight 22 and surrounded by a jacket 23 . Steam is supplied to the jacket 23 by a heating system 24 so that the steam condenses in the jacket generated a liquid which runs back along the bottom of the jacket to an outlet port 25 from which the liquid runs back to the heating system 24 . The jacket surrounds substantially the whole of the duct and the duct extends substantially the whole of the distance from the well head 11 to the tank 13 .
[0054] The auger flight 22 is driven by a motor 26 on the well head end of the duct 21 . A temperature sensor 27 detects the temperature of the materials within the duct at the tank 13 so as to control the heat supply from the heating system 24 to maintain a required temperature as a material to enter the tank.
[0055] The motor 26 drives the auger flight in a direction so that the flight tends to carry particulate materials within the bottom of the duct toward the tank end. The end of the duct within the tank includes a discharge mouth 33 which is arranged within the tank so that the discharged materials can rise centrally within the tank if lighter or can fall downwardly within the tank, primarily the particulate materials, the heavier materials falling into a collection system 34 arranged centrally of the tank for collecting and discharging the materials as a primary discharge system. (See FIGS. 4 and 5 )
[0056] The auger flight has a ribbon flight section 22 C at least in the area closest to the tank so as to allow the liquids to flow through the centre of the ribbon flight section with less turbulence providing a smoother flow of the liquids after the particulate materials have been primarily extracted for transport to the plug. The ribbon flight may extend along the complete length of the auger which is along the complete length of the heated duct so as to allow the fluid to flow in the center and the particulates to be carried along the bottom of the duct to the tank.
[0057] The outlet mouth of the duct may be located at the tank wall rather than in the centre as shown in FIG. 1 .
[0058] In FIG. 2 is shown an arrangement in which the lighter materials rise through a secondary inlet duct portion 40 so that the lighter materials, primarily the oil can be raised through the duct 40 to a mouth 41 injecting into the tank 13 at a position above the expected water level. The heavier materials in the duct transfer through the mouth 33 at the side wall into the tank primarily below the water level. The liquid rising in the duct 40 can be heated by a heat exchanger 42 from the flue pipe of the heating system 24 .
[0059] Also in FIG. 2 is shown a vent duct 50 which allows gases in the stream to be released from the stream above the liquid level to avoid discharging bubbles into the liquid which can cause circulating currents which can interfere with the settlement within the production tank. The heat in the transfer duct 20 can be as much as 140 degrees C. so that water can be converted to steam which would generate bubbles in the tank if released into the tank. The vent 50 may discharge into the tank or may discharge to atmosphere.
[0060] An additional return line can be provided from the well head end of the duct to the tank so as to use the system in reverse flow arrangement for heating of liquid within the tank by passing the materials through the duct in the reverse direction and then returning the materials to the tank through the return duct. This allows the tank to avoid the necessity for a specific heating system within the tank since the majority of the tank can be initially heated using the circulation system and then when the production is started, the heat from the duct is sufficient to maintain the materials within the tank at the required separation temperature. This avoids the generation of convection currents within the tank and maximises the settling action. In FIG. 3 is shown a end elevational view of the system including the heater 24 including a burner 24 A and heat exchange tubes 24 B. The flue 24 C can be allowed to merely discharge the gases or can be connected to the heat exchanger 42 shown in FIG. 2 . The steam from the heat exchange tube 24 B is communicated through a duct 24 D to the inlet of the jacket 23 . The return from the jacket returns the liquid to the heater 24 . The duct is mounted on one or more support legs 50 and arranged so that it is generally horizontal but with a slight inclination so as to run the return liquid back toward the outlet for the heater.
[0061] There has been very little work done on technology involving the atmospheric treating of petroleum products in recent years. It is believed that by incorporating a number of certain advancements in recent technology developed by the present Assignee, a significant step forward will be made.
[0062] In particular, the utilization of:
1. Auger tank de-sanding, as is known and provided by the present Assignee. 2. Two phase thermo siphon tank heating as shown in the Lange patent application mentioned herein before. 3. And a combination of both between the flow line and storage tank will create a low cost, very effective mini or micro treating system that simply does not exist today.
[0066] The components can be made any length, diameter or material make up that is required to achieve the desired temperature rise or fall, (this system may also be a cooler).
[0067] The heating system disclosed in the above PCT application of Lange has a condenser portion which may be the jacketed are however it may also include the auger shaft as well as the flighting section if rotating mechanical seals and double wall auger flighting were incorporated. The heating system may utilize a condenser of standard design in the production tank (controlled by flow valves) the greatest amount of heat however will go to the heating of the duct 20 .
[0068] The following features may be considered in the flighting designs:
1. The auger design may incorporate multi purpose capability. 2. Simple helical flights of standard design can be used for low cost solutions. 3. Variable pitch screw of same outside diameter to allow for velocity drop after temperature is up and chemical is mixed. 4. Paddles or weirs in the auger tube can be used to enhance mixing and heat distribution into petroleum products. 5. Perforations, slots, holes in the flight, or other flighting modifications either whole or in part of the auger, can be used to both promote mixing, heating, shearing and subsequent separating of H20, crude and solids. 6. An unimpeded fluid flow can be created by use of a ribbon auger flight in last stages of the auger. The ribbon outer lead edge of the flight still allows for solids distribution into production tanks.
[0075] In one mode of operation the system is used in unidirectional operation where in a first method of operation, the system is installed on typical production well with tank located 75 feet from the wellhead. The storage tank access port is a standard 10″ full opening knife gate valve either retro-fit by hot tap installation or standard install when tank is empty, as is well known to one skilled in the art.
[0076] The valve is installed inline with wellhead, approximately 5 feet above tank floor. On a retrofit the existing crude flow line is cut, threaded and with a flex coupling and valve tied into the flow line inlet on the system. The original flow line is tied into the other side of the tee with a valve.
[0077] The production fluid follows the helical path defined by the flight taking advantage of retention time and velocity drop through the larger diameter flow line.
[0078] The internal screw, through a packing gland, is driven by hydraulic return pressure or electric over gear drive.
[0079] The auger drive incorporates centralized and thrust components along with secondary centralisers, throughout the length of the screw to maintain the shaft central within the duct. The auger is driven to rotate either continuously, or intermittently from 0 to higher RPM, generally approximately 5 RPM.
[0080] The heating system is well known to one skilled in the art. A small 9-burner unit can be affixed directly onto the transfer duct or alternatively have hoses and valves to control temperature to the tank condenser.
[0081] The transfer duct may have flat irons affixed to direct steam away in the upper half of the tube and return in the lower half. The transfer duct will be slightly sloped toward the return outlet so the jacket will quickly return condensate liquid to the heating system.
[0082] In a second method of operation, in a case where the tank is cold the auger may be rotated in reverse to bring cold crude into the MPT for heating. The previous inlet to the NVT is now the exit with the crude being recycled into the production tank.
[0083] Chemical may be injected to batch treat slop or hard to treat crude in this manner. Temperature rise could be achieved by counter rotation, and then once temperature rise was achieved, the auger would be rotated to the treating mode. The use of the auger flight improves chemical mixing.
[0084] In an alternative arrangement (not shown) where the duct 20 transports the production from the well to a pump. At the pump is provided a discharge valve which is periodically operable to discharge the particulate materials into a collection system for discard.
[0085] The auger flight is arranged so that it increases the quantity of particulate material at the discharge end adjacent the valve so as to form in effect a plug of the particulate material blocking the duct at that area. Thus when the valve is opened a portion of the plug can be discharged without the plug being broken up or wholly discharged so that the plug prevents the escape of the liquid materials within the duct while allowing the plug itself to be partially discharged. The valve can be operated periodically by a pressure sensor which detects the pressure in the plug due to the packing of the plug with additional particulate materials as the materials are fed by the auger flight. The oil from the duct 20 is to the pump is removed from the duct 20 at an outlet point downstream of the plug.
[0086] Since various modifications can be made in our invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. | In a method of crude oil production where at a well head a mixture of particulates, crude oil and water is produced for storing in a production tank for settlement of the mixture in to the constituent parts for separate extraction from the tank or the mixture is pumped though a pipeline to a remote location, the mixture is transferred from the well head to the production tank or to the pipeline through a transfer duct in which an initial separation of the mixture is caused by heating material in the duct by a surrounding jacket and by running an auger flight with a ribbon flight in the duct which carries the particulate materials along the duct for discharge. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a device for guiding the warp yarns in three different positions via a plurality of vertically mobile griffe frames.
DESCRIPTION OF THE RELATED ART
Devices of this type are known to exist, which generally comprise one single griffe frame, as described in French Patent No. 1 513 410 of Dec. 9, 1966.
It is desired that two hooks, selectively controlled by two needles, cooperate with the same griffe frame. At each of the ends of the two hooks are fixed the ends of a cord which passes around a pulley, which is connected via a small rod to another pulley, thus forming a tackle assembly. Around this second pulley another cord, of which one of the ends is secured to the frame and the other end includes a collar associated with a heddle. In this device, the two hooks are selectively controlled by two needles, and the two knives with which they cooperate form part of the same griffe frame, thus allowing the collar provided with the warp yarn to arrive either in an upper position, in an intermediate position or in a lower position. The upper and lower positions are respectively reached when the two hooks are retained by the griffe frame and their vertical stroke is equal to that of the frame. The intermediate position is established when one of the two hooks is in mesh with the griffe frame, thereby making it possible to displace the collar by half the vertical stroke of the other positions.
Similarly, Swiss Patent No. 367 452 of Apr. 19, 1958 describes a double-lift weaving mechanism in the form of two hooks joined by a cord which passes, as in the French Patent, around one pulley of a tackle assembly, of which the other pulley cooperates with a cord having a fixed end.
To produce a three-position weaving mechanism, two systems with two hooks must be used, of which the second pulleys of the tackle assemblies are surrounded by a cord with fixed ends and which encircles the first pulley of a third tackle assembly of which the other pulley is encircled by a harness cord with a fixed end.
The three-position weaving mechanisms described in the prior art Patents present certain drawbacks as far as the vertical guiding of the different tackle assemblies is concerned. These assemblies tend to move horizontally during different strokes, and appropriate guiding elements must therefore be provided the cost of such guide element is high and the elements considerably complicate the structure of the mechanism.
It is a particular object of the present invention to overcome the drawbacks set forth hereinbefore.
SUMMARY OF THE INVENTION
The three-position weaving mechanism according to the invention is characterized in that it includes:
two adjacent shed-forming devices each including two hooks vertically movable under the effect of knives which move in opposition, in a reciprocating movement. These hooks are joined by a cord passing around one of the pulleys of a tackle assembly;
a pulley mounted idly on a shaft which is fixed in relationship with respect to the frame of the mechanism;
and a cord of which one of the ends is anchored to the frame of the mechanism and which successively passes over the second pulley of the tackle assembly of the first shed-forming device, the idle pulley, and the second shed-forming pulley of the tackle assembly of the second device. The second end of the cord is connected with a collar to which at least one heddle is fastened.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:
FIGS. 1 to 3 are side elevational views illustrating the assembly of the elements of a weaving mechanism according to the invention, with the collar of the harness being respectively in lower, intermediate and upper position.
FIG. 4 is a view similar to that of FIG. 1, but illustrating a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIG. 1 shows two shed-forming devices A and B each comprising two movable hooks 1 and 2 adapted to cooperate with two griffe frames 3 and 4 having knives 3a and 4a.
Hooks 1 and 2 include a rectilinear principal arm 1a and 2a of which the upper end is provided with a barb 1b and 2b, while their lower ends are bent to form a second, vertical, arm 1c, 2c, provided with a hooks, 1d, 2d cooperating respectively with bars 5a and 5b of the comberboard grid 5.
Each of the arms 1a, 2a of hooks 1 and 2 passes in the ring of a press needle referenced 6a, 6b and 7a, 7b which, in known manner, makes it possible for the barbs 1b, 2b to be displaced from the knives 3a, 4a when it is not desired that the hooks be gripped by the knives.
Links 1e, 2e of arms 1a-2c or 1a-2c respectively of hooks 1 and 2 are joined by a cord 8 passing around a pulley 9a of a tackle assembly 9.
Between the two devices A and B, a pulley 10 has been provided, rotating freely about a spindle 11 secured to the frame 12 of the weaving mechanism. The second pulleys 9b of the two tackle assemblies 9 of the two devices A and B, and pulley 10 are engaged by another cord 13 of which one of the ends 13a is attached to a fixed point 12a of the frame 12, while its other end 13b carries a snap 14 which constitutes the collar to which at least one heddle 15 is fixed.
A double tackle assembly is thus produced, enabling the three desired positions of the collar 14 to be obtained, namely a low position corresponding to the lower position of the warp yarns (FIG. 1), a horizontal or intermediate position thereof (FIG. 2) and a high or upper position of these yarns (FIG. 3).
When the warp yarns are to be in low position (FIG. 1), the arms 1a of devices A and B are pressed so that knife 4a does not engage the corresponding barbs 1b when the griffe frame 4 rises. Similarly, the hooks 2 are pressed so that barbs 2b are engaged by the knife 3a corresponding to the griffe frame 3 when it rises. In this way, the collar 14 remains in the low position and all the hooks 1d, 2d of devices A and B rest on the bars 5a, 5b of the grid 5.
The intermediate position shown in FIG. 2 is produced by the fact that the arms 1a, 2a of the hooks 1 and 2 of device A are pressed alternately, so that the hooks 1d, 2d are in abutment against the bars 5a, 5b of the grid 5. On the contrary, barbs 1b, 2b of the hooks of device B remain in mesh with the knives 3a, 4a during the reciprocating movement of the griffe frames 3 and 4.
Finally, if collar 14 is in the high position (FIG. 3), the barbs 1b, 2b of the four hooks 1 and 2 of devices A and B are left in mesh with the knives 3a, 4a of the two griffe frames 3 and 4.
Of course, the preceding arrangement may also be applied to a weaving mechanism of the type described in Applicants' U.S. Pat. No. 4,739,806.
FIG. 4 shows a module 16 comprising a plurality of vertical partitions 16a, 16b, etc . . . , between each of which are located the shed-forming devices A, B, C, D . . . , each constituted by two hooks 17, 18 joined by a cord 19 passing over the first pulley 20a of a tackle assembly 20 guided between the partitions.
These hooks 17, 18 move vertically via knives disposed on griffe frames (not shown) and exhibit a reciprocating movement. Retaining elements associated with electro-magnets are capable of retaining the mobile hooks 17, 18 in high position. Such a structure according to U.S. Pat. No. 4,739,806 will not be described in greater detail, however the teachings of the patent are incorporated herein by reference.
In accordance with the invention, an idle pulley 21 has been provided, of which the shaft for rotation 21a is secured on a horizontal wall or element 16c of the module 16. The second pulleys 20b of the tackle assemblies 20 of two devices A and B of the module 16 and the idle pulley 21 are engaged by a cord 22 of which one of the ends 22a is anchored to a fixed point 16d of the module. While its other end 22b carries a snap 23 which constitutes the collar to which at least one heddle 24 is fixed.
A double tackle assembly is thus obtained, making it possible to produce the three positions described hereinabove, but applied to a module described in Applicants' aforementioned U.S. patent and which requires no additional guiding means with respect to those of a standard module, with the result that a mechanism thus produced is economical and highly simple to manufacture and maintain.
It must, moreover, be understood that the foregoing description has been given only by way of example and that it in no way limits the domain of the invention which would not be exceeded by replacing the details of execution described by any other equivalents. | A three-position weaving mechanism for a weaving loom which includes a plurality of shed-forming devices having tackle assemblies disposed in side by side relationship and wherein the lower pulleys of adjacent tackle assemblies are joined by a cord which passes over such pulleys and an intermediate idler pulley which is secured to the frame of the weaving loom. | 3 |
TECHNICAL FIELD
[0001] This invention relates to ultrasonic diagnostic imaging systems and, in particular, to a method and apparatus for obtaining three-dimensional ultrasonic Doppler images of moving sound reflectors in blood and tissues.
BACKGROUND OF THE INVENTION
[0002] A variety of ultrasound imaging modalities have been developed to suit a variety of specific applications. For example, Doppler imaging has been developed to allow the imaging of moving ultrasound reflectors. Doppler ultrasound imaging systems detect a Doppler shift in the frequency of a transmitted signal reflected from ultrasound reflectors, and display returns only from such reflectors. The magnitude of the Doppler shift corresponds to the velocity of the ultrasound reflectors, and the polarity of the Doppler shift corresponds to the direction of movement. Conventional Doppler images are thus able to provide an indication of both blood flow velocity and blood flow direction, thereby allowing arterial blood flow to be differentiated from venous blood flow. Doppler imaging can also be used to visualize the movement of tissues, such as heart wall movement.
[0003] Although Doppler imaging provides a great deal of clinically useful information, Doppler imaging is not without its problems and limitations. The magnitude of the Doppler shift corresponds to the projection of the velocity of the blood flow on the ultrasound beam. The Doppler shift from blood flowing at an angle to the axis of the ultrasound beam corresponds to the product of the blood flow velocity and the cosine of the angle between the direction blood flow direction and the axis of the beam. Therefore, the velocity of blood flow can be accurately determined and portrayed in an ultrasound Doppler image only if the angle between the blood flow and the axis of the ultrasound beam is known. Yet it can be difficult to make this determination.
[0004] Even if the angle between the axis of the ultrasound beam and an artery or vein is known, it can still be difficult or impossible to accurately determine the velocity of blood flowing through the blood vessel because the flow of blood through a vessel is not always aligned with the axis of the vessel. Blood can flow through a blood vessel in a helical manner. Furthermore, the flow of blood in a blood vessel becomes even more irregular in the presence of bends, bifurcations or obstructions in the vessel. Thus, a single cosine correction angle cannot be used to accurately correct signals indicative of the velocity of moving reflectors in an artery or vein.
[0005] In conventional Doppler imaging systems, a two-dimensional Doppler image is obtained by using an ultrasound transducer having a linear, one-dimensional array of transducer elements. Signals applied to or received from the array are combined to form a beam that is steered by phase-shifting the signals to sample locations in a two-dimensional plane. If each sample location in the two-dimensional plane is interrogated from two different apertures, i.e., by two different beams emanating from different locations, the absolute mean velocity of flow at that sample location can be determined in two dimensions. However, such systems are incapable of accurately portraying the true flow velocity because the true velocity may have a component that is perpendicular to the two-dimensional plane.
[0006] One approach to determining blood flow in three dimensions is disclosed in U.S. Pat. No. 5,522,393 to Philips et al., which discloses a system using a transducer having a non-planar phased array that interrogates each sample volume using three independently steered beams. Although the two-dimensional phased arrays taught by the Philips et al. patent are capable of accurately determining the velocity of blood flow in three dimensions, the structure of the transducers disclosed in the Philips et al. patent make them difficult to use. In particular, because the faces of the arrays are curved, it can be difficult to maintain good acoustic contact with the surface of tissues to be imaged unless the curvature of the surface is substantially the same as the curvature of the face of the array. However, the curvature of the array face will not generally match the curvature of the surface of tissues to be imaged. The approach described in the Philips et al. patent thus has a limited range of applications. Furthermore, the large number of elements in the array each located in a different three-dimensional position produce respective signals that can be combined only with a great deal of computational complexity.
[0007] There is therefore a need for a system and method for providing a three-dimensional Doppler image using an ultrasound transducer that can be used with relative ease and that produces signals that can be combined to create the image with relatively little computational complexity. Furthermore such a system should be capable of imaging both blood flow and tissue motion, in order to determine the true velocity of both heart and vessel wall motion. Delineation of the direction of motion will both make the diagnosis easier and allow better understanding of the source of the motion abnormality.
SUMMARY OF THE INVENTION
[0008] An ultrasonic imaging system for generating a three-dimensional Doppler image includes a scanhead and an imaging unit. The scanhead includes a transmit aperture, and at least three receive apertures arranged in a common plane. The imaging unit includes a beamformer coupled to the receive apertures. The beamformer combines signals from several transducer elements in each of the receive apertures to generate signals indicative of ultrasound Doppler returns from a selected volume adjacent the receive aperture. Respective Doppler processors for the receive apertures generate respective magnitude signals indicative of the Doppler flow magnitude of moving ultrasound reflectors in the selected volume and a direction signal indicative of the direction of the moving ultrasound reflectors in the selected volume. A velocity estimator is coupled to receive the magnitude and direction signals from each of the Doppler processors. The velocity estimator generates a magnitude signal indicative of the magnitude of a three-dimensional flow vector corresponding to the magnitude signals from the Doppler processors and a flow angle signal indicative of the direction of the three-dimensional flow vector corresponding to the direction signals from the Doppler processors. The imaging system also includes a display processor coupled to receive the magnitude signal and the angle signal from the velocity estimator. The display processor converts the magnitude and angle signals to display signals having a predetermined display format.
[0009] The transmit aperture is preferably positioned symmetrically between the receive apertures and in the common plane of the receive apertures. In one aspect of the invention, the scanhead may include a first pair of receive apertures positioned in the common plane along a first axis, and a second pair of receive apertures positioned in the common plane along a second axis that is perpendicular to and intersects the first axis. In this configuration, the transmit aperture may be positioned in the common plane at the intersection of the first and second axes. In another aspect of the invention, the scanhead may include a plurality of receive apertures equally spaced from a center point of the scanhead and circumferentially spaced from each other. The receive apertures may have a hexagonal shape, and the transmit aperture may be centered at the center point between the receive apertures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is an isometric view of one embodiment of a three-dimensional Doppler ultrasound imaging system in accordance with the present invention.
[0011] [0011]FIG. 2 is a plan view of a transducer face according to one embodiment of a scanhead that is may be used in the imaging system of FIG. 1.
[0012] [0012]FIGS. 3A and 3B are schematic views and vector diagrams showing the two orthogonal planes in which blood flow is measured using the scanhead of FIG. 2.
[0013] [0013]FIGS. 4A and 4B are vector diagrams illustrating the manner in which the Doppler flow vectors shown in FIGS. 3A and 3B, respectively, are resolved into composite vectors that may have two orthogonal components.
[0014] [0014]FIG. 5 is a vector diagram illustrating the manner in which the composite vectors shown in FIGS. 4A and 4B, respectively, are resolved into a three-dimensional composite vector that may have three orthogonal components.
[0015] [0015]FIG. 6 is a block diagram of one embodiment of an ultrasound imaging unit used in the ultrasound imaging system of FIG. 1.
[0016] [0016]FIG. 7 is a plan view of a transducer face according to another embodiment of a scanhead that is may be used in the imaging system of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0017] One embodiment of a system 10 for producing a Doppler three-dimensional image is shown in FIG. 1. The ultrasound imaging system 10 includes a scanhead 20 having a transducer face 24 that will be described in greater detail below. Electric signals are coupled between the scanhead 20 and an imaging unit 30 through a cable 26 . The imaging unit 30 is shown mounted on a cart 34 . A display monitor 40 having a viewing screen 44 is placed on an upper surface of the imaging unit 30 .
[0018] The transducer face 24 of the scanhead 20 is shown in greater detail in FIG. 2. The face 24 is planar, and it has a first pair of receive apertures 50 , 52 extending along a first axis 54 , and a second pair of receive apertures 56 , 58 extending along a second axis 60 that is perpendicular to the first axis 54 . Each receive aperture 50 - 58 is formed by a plurality of transducer elements 62 generating respective electrical signals responsive to received ultrasound returns. The phasing of the signals from the transducer elements 62 may be adjusted to effectively steer and focus the received ultrasound returns to various directions and depths. A transmit aperture 66 is located at the intersection of the two axes 54 , 60 . Since the face 24 of the scanhead 20 is planar, it can maintain contact with the surface of tissues to be imaged (not shown) with substantially the same ease that a conventional one-dimensional transducer array (not shown) can maintain contact with the surface of tissues to be imaged. Furthermore, since only four apertures 50 , 52 , 56 , 58 are used to generate signals from ultrasound returns, the signals can be combined to form signals indicative of a three-dimensional flow vector with relatively little computational complexity.
[0019] The manner in which the scanhead 20 shown in FIG. 2 can determine flow vectors in three dimensions will now be explained with reference to FIGS. 3A and 3B. After the transmit aperture 66 directs ultrasound to tissues adjacent the array face 24 , each of the receive apertures 50 , 52 detects reflected ultrasound signals. Based on the time at which each portion of the ultrasound signal is received by the transducer elements 62 in each aperture 50 , 52 , the distance and angle of a sample volume relative to the center of each receive aperture 50 , 52 can be determined. Each aperture 50 , 52 determines the magnitude of a Doppler flow vector from the sample volume based on the frequencies of the ultrasound returns from the sample volume. For example, with reference to FIG. 3A, the receive aperture 50 is first steered and focused to receive ultrasound returns along a beam 70 , and subsequently steered and focused to receive ultrasound returns along a beam 72 . With reference to the Doppler shift of the ultrasound returns received along the beam 70 , a flow vector 74 having a magnitude corresponding to the projection of the speed of the ultrasound reflectors along the beam 70 can be determined. Similarly, a vector 78 having a magnitude corresponding to the projection of the speed of the ultrasound reflectors along a beam 80 can be determined. Based on these two projected vectors 74 , 78 , a composite two-dimensional flow vector can be determined by conventional means. For example, as shown in FIG. 4A, the projected flow vector 74 combined with the projected flow vector 78 results in a composite two-dimensional flow vector 90 . The sole component of the vector 90 is in a plane that is perpendicular to the transducer face 24 and containing the axis 54 (FIG. 3A). Any velocity component in a direction perpendicular to this plane cannot be detected by the receive apertures 50 , 52 . The receive apertures 50 , 52 are thus only capable of generating a two-dimensional Doppler image.
[0020] As shown in FIG. 3B, ultrasound returns are received by the receive apertures 56 , 58 in the same manner that the receive apertures 50 , 52 receive ultrasound returns. In the example of FIG. 3B, the ultrasound returns received by the receive apertures 56 and 58 are “off-axis”, i.e., steered to one side. With reference to the Doppler shift of the ultrasound returns received along the beam 94 a flow vector 97 having a magnitude corresponding to the projection of the speed of the ultrasound reflectors along the beam 94 can be determined. Similarly, a vector 98 having a magnitude corresponding to the projection of the speed of the ultrasound reflectors along a beam 96 can be determined. Based on these two projected vectors 97 , 98 , a composite two-dimensional flow vector we can be determined by conventional means. The composite flow vector 92 along the beam has a first component 100 that is perpendicular to the axis 60 (FIG. 3B) and a second component 102 that is parallel to the axis 60 , as shown in FIG. 4B. The composite vector 92 lies in a plane that contains the axis 60 and is perpendicular to the face 24 of the scanhead 20 . The vector components 100 , 102 also lie in this plane. Any velocity component not in this plane cannot be detected by the receive apertures 56 , 58 . The receive apertures 56 , 58 are thus only capable of generating a two-dimensional Doppler image. The two-dimensional Doppler image is in a plane that is perpendicular to the plane in which a two-dimensional Doppler image can be generated by the receive apertures 50 , 52 (FIG. 3A). It will be appreciated that the ultrasound beams can be steered in any direction relative to the scanhead face 24 and apertures 50 , 52 , 56 , 58 and that the directions shown in FIGS. 3A and 3B are examples of only two planar directions which may be employed.
[0021] The manner in which ultrasound returns from the four receive apertures 50 , 52 , 56 , 58 can be used to provide a three-dimensional Doppler vector will now be explained with reference to FIG. 5. FIG. 5 shows the planar face 24 of the scanhead 20 and the axes 54 , 60 described above with reference to FIGS. 2 - 4 . A volume 110 is defined by a three-dimensional Cartesian coordinate system having a transverse dimension 112 , a longitudinal dimension 114 , and an axial dimension 116 . The axial dimension 116 and the longitudinal dimension 114 define a plane that includes the axis 54 and is perpendicular to the face 24 of the scanhead 20 . As explained above, the receive apertures 50 , 52 (FIGS. 2 and 3A) are capable of detecting Doppler flow vectors to create a composite two-dimensional flow vector in this plane. As also explained above with reference to FIG. 4B, this composite two-dimensional flow vector can be divided into two vector components, one extending in the longitudinal dimension 114 and one extending in the axial dimension 116 . This composite two-dimensional flow vector may also be defined in a polar coordinate system by a two-dimensional flow vector 120 having a magnitude V 1 and an angle θ LONGITUDINAL measured from the axial direction. Similarly, the axial dimension 116 and the transverse dimension 112 define a plane that includes the axis 60 and is perpendicular to the face 24 of the scanhead 20 . As also explained above, the receive apertures 56 , 58 (FIGS. 2 and 3B) are capable of detecting Doppler flow vectors to create a composite two-dimensional flow vector in this plane. As also explained above with reference to FIG. 4A, this composite two-dimensional flow vector can be divided into two vector components, one extending in the transverse dimension 112 and one extending in the axial direction 116 . This composite flow vector may also be defined in a polar coordinate system by a two-dimensional flow vector 124 having a magnitude V 2 and an angle θ TRANSVERSE measured from the axial direction 116 . The two-dimensional flow vectors 120 , 124 may be further combined to create a three-dimensional flow vector 130 that may have components extending in the transverse direction 112 , the longitudinal direction 114 , and the axial direction 116 . This flow vector 130 is a true three-dimensional vector. Individual three-dimensional flow vectors may be obtained in this manner for a large number of sample volumes in the volume 110 being imaged. The true velocity of blood flowing through a vessel can therefore be determined and imaged even though the flow may be helical or in some other even more irregular pattern.
[0022] Using the techniques described above, an imaging system of the present invention can be used to provide a three-dimensional image of moving tissues, such as the movement of the heart wall. However, in being used for these applications, the system needs to be modified to selectively respond to lower Doppler frequencies when imaging tissues as compared to the Doppler frequency of interest when imaging blood flow. The likely range of angles of motion will also usually be different to those seen with flow.
[0023] One embodiment of an imaging unit 30 (FIG. 1) that may be coupled to the scanhead 20 is shown in FIG. 6. The imaging unit 30 includes a beamformer 212 that effectively steers and focuses ultrasound beams received by the receive apertures 50 - 58 in the scanhead 20 to form scanlines of coherent echo signals. Output signals from the beamformer are applied to four Doppler processors 214 a-d, which perform Doppler estimations of the Doppler phase shift or signal intensity (power Doppler) and generate signals indicative of the velocity, both direction and magnitude, of ultrasound returns received by the respective receive apertures 50 , 52 , 56 , 58 . More specifically, the first Doppler processor 214 a determines velocity from ultrasound returns received by the receive aperture 50 , the Doppler processor 214 b determines velocity from ultrasound returns received by the receive aperture 52 , the Doppler processor 214 c determines velocity from ultrasound returns received by the receive aperture 56 , and the Doppler processor 214 d determines velocity from ultrasound returns received by the receive aperture 58 . Conventionally this is done by Fourier transform or autocorrelation of Doppler signal data.
[0024] Based on the outputs from the Doppler processors 214 , a velocity vector estimator 218 is able to determine the magnitude and direction of a composite Doppler motion vector in three dimensions. The velocity vector estimator produces a first signal V indicative of the magnitude of the flow vector, a second signal θ TRANSVERSE indicative of the transverse angle, and a third signal θ LATERAL indicative of the lateral angle. These signals are applied to a display processor 220 , which converts the signals to an appropriate format for subsequent display. For example, the display processor 220 may format the signals so that magnitude of flow velocity or tissue motion is portrayed by color or intensity. The signals from the display processor 220 are applied to a video processor 250 , which generates appropriate video signals, such as NTSC signals, for presentation on a suitable display 260 , which may be a cathode ray tube.
[0025] The output signals from the beamformer 212 are also applied to a B Mode Processor 230 , which processes amplitude information of the output signals from the beamformer 212 on a spatial basis. The B Mode Processor 230 generates signals that are applied to the Video Processor 250 to provide a structural image, preferably in three dimensions, of the tissue in the volume from which a Doppler image is being obtained. The structural image is preferably overlaid in the display 260 on the three-dimensional Doppler image.
[0026] A scanhead 20 having two pairs of receive apertures 50 , 52 and 56 , 58 arranged along axes 54 , 60 that are perpendicular to each other is preferred for ease of processing the signals generated by the receive apertures. Specifically, the receive apertures 50 , 52 and 56 , 58 lying along the same axis 54 and 60 , respectively, can be processed together to obtain a composite two-dimensional motion vector in respective planes that are perpendicular to each other, as previously explained. These two-dimensional vectors can then be combined to create a three-dimensional flow vector, as also previously explained. However, the invention may be practiced with any scanhead having three or more receive apertures arranged in a common plane. For example, as shown in FIG. 7, a scanhead 20 ′ has a transducer face 300 containing three receive apertures 310 , 312 , 314 . Located between the receive apertures 310 - 314 is a single transmitter aperture 320 . The scanhead 20 ′ has the advantage of using fewer receive apertures compared to the scanhead 20 of FIG. 2. However, it has the disadvantage of being computationally more difficult to combine the outputs from the receive apertures 310 - 314 because pairs of adjacent receive apertures 310 - 314 can determine a two-dimensional motion vector lying along each of three planes intersecting each other at 60 degrees.
[0027] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims. | An ultrasonic imaging system uses a specially configured scanhead to provide ultrasound return signals that are processed by an imaging unit to generate a three-dimensional Doppler ultrasound image. One embodiment of the scanhead includes a first pair of apertures aligned along a first axis, and a second pair of apertures aligned along a second axis that is perpendicular to the first axis. All of the apertures lie in a common plane. Respective signals from the apertures along each axis are processed to generate two-dimensional Doppler motion vectors. The resulting pairs of two-dimensional Doppler motion vectors are then processed to generate three-dimensional Doppler motion vectors that are used to generate a three-dimensional Doppler image. In another embodiment, three co-planar apertures are arranged equidistantly from each other about a common center, and the three-dimensional Doppler image is generated from respective signals from the apertures. | 8 |
This application claims priority to U.S. Provisional Application No. 61/816,136, which was filed Apr. 25, 2013, and which is fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to network-based computer security and more particularly to methods of and systems for authenticating a device for computer network security.
2. Description of the Related Art
Device identification through digital fingerprinting has proven to be invaluable in recent years to such technologies as security and digital rights management. In security, authentication of a person can be restricted to a limited number of previously authorized devices that are recognized by their digital fingerprints. In digital rights management, use of copyrighted or otherwise proprietary subject matter can be similarly restricted to a limited number of previously authorized devices that are recognized by their digital fingerprints.
Digital fingerprints are particularly useful in uniquely identifying computing devices that are historically know as “IBM PC compatible”. Such devices have an open architecture in which various computer components are easily interchangeable with compatible but different components. There are two primary effects of such an open architecture that facilitate device identification through digital fingerprints.
The first facilitating effect is diversity of device components. Since numerous components of IBM PC compatible devices are interchangeable with comparable but different components, generation of a digital fingerprint from data associated with the respective components of the device are more likely to result in a unique digital fingerprint.
The second facilitating effect is discoverability of details of the various components of IBM PC compatible devices. Since the particular combination of components that make up a given device can vary widely and can come from different manufacturers, the components and the operating system of the device cooperate to provide access to detailed information about the components. Such information can include serial numbers, firmware version and revision numbers, model numbers, etc. This detailed information can be used to distinguish identical components from the same manufacturer and therefore improves uniqueness of digital fingerprints of such devices.
Laptop computing devices evolved from desktop computing devices such as IBM PC compatible devices and share much of the architecture of desktop computing devices, albeit in shrunken form. Accordingly, while users are much less likely to replace graphics circuitry in a laptop device and components therefore vary less in laptop devices, laptop devices still provide enough detailed and unique information about the components of the laptop device to ensure uniqueness of digital fingerprints of laptop devices.
However, the world of computing devices is rapidly changing. Smart phones that fit in one's pocket now include processing resources that were state of the art just a few years ago. In addition, smart phones are growing wildly in popularity. Unlike tablet computing devices of a decade ago, which were based on laptop device architectures, tablet devices available today are essentially larger versions of smart phones.
Smart phones are much more homogeneous than older devices. To make smart phones so small, the components of smart phones are much more integrated, including more and more functions within each integrated circuit (IC) chip. For example, while a desktop computing device can include graphics cards and networking cards that are separate from the CPU, smart phones typically have integrated graphics and networking circuitry within the CPU. Furthermore, while desktop and laptop devices typically include hard drives, which are devices rich with unique and detailed information about themselves, smart phones often include non-volatile solid-state memory, such as flash memory, integrated within the CPU or on the same circuit board as the CPU. Flash memory rarely includes information about the flash memory, such as the manufacturer, model number, etc.
Since these components of smart phones are generally tightly integrated and not replaceable, the amount and variety of unique data within a smart phone that can be used to generate a unique digital fingerprint is greatly reduced relative to older device architectures. In addition, since it is not expected that smart phone components will ever be replaced, there is less support for access to detailed information about the components of smart phones even if such information exists.
Accordingly, it is much more difficult to assure that digital fingerprints of smart phones and similar portable personal computing devices such as tablet devices are unique. What is needed is a way to uniquely identify individual devices in large populations of homogeneous devices.
SUMMARY OF THE INVENTION
In accordance with the present invention, a device authentication server authenticates a remotely located device using data representing pixel irregularities of a display of the device. Some LED monitors allow pixels to be read such that data representing the color actually shown by the pixels can be obtained. By writing test data to each pixel and reading the color displayed by the pixel, hot and dead sub-pixels can be identified. Since each display will deteriorate in a unique and randomized way, a unique mapping of pixel irregularities of a display of a device will be unique.
By combining unique map of pixel irregularities of a display of the remotely located device, the device can be distinguished from similar devices when other attributes alone are insufficient to uniquely identify the device.
For registration for subsequent authentication of the device, the device provides the device authentication server with data representing a relatively complete set of pixel irregularities, sometimes referred to as pixel irregularity data, that the device retrieves from the display. The device authentication server stores this data and uses it subsequently as reference pixel irregularity data.
In subsequent authentication of the device, the device authentication server sends a device key challenge to the device. The device key challenge specifies a randomized selection of device attribute parts to be collected from the device and the manner in which the device attribute parts are to be combined to form a device key. The device key is data that identifies and authenticates the device and includes a device identifier and pixel irregularity data.
The device authentication server authenticates the device when the device identifier of the device key identifies the device and the pixel irregularity data is consistent with the reference pixel irregularity data.
BRIEF DESCRIPTION OF THE DRAWINGS
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the invention. In the drawings, like reference numerals may designate like parts throughout the different views, wherein:
FIG. 1 is a diagram showing a computing device, a server, and a device authentication server that cooperate to identify and authenticate the device in accordance with one embodiment of the present invention.
FIG. 2 is a transaction flow diagram illustrating the manner in which the device is registered with the device authentication server for subsequent authentication.
FIG. 3 is a transaction flow diagram illustrating the manner in which the device, the server, and the device authentication server of FIG. 1 cooperate to authenticate the device.
FIG. 4 is a block diagram of a map of pixel irregularities to be used for authentication of the device of FIG. 1 .
FIG. 5 is a block diagram of a known device record used by the device authentication server to authenticate the device.
FIG. 6 is a logic flow diagram of an authentication process by which the device authentication server authenticates the device.
FIG. 7 is a logic flow diagram illustrating the extraction of pixel irregularity data for registration of the device.
FIG. 8 is a logic flow diagram illustrating comparison of pixel irregularity data to reference pixel irregularity data for authentication of the device.
FIG. 9 is a block diagram showing in greater detail the server of FIG. 1 .
FIG. 10 is a block diagram showing in greater detail the device authentication server of FIG. 1 .
FIG. 11 is a block diagram showing in greater detail the device of FIG. 1 .
FIG. 12 is a block diagram showing division of a display of the device of FIG. 1 into equal areas in accordance with one embodiment of the present invention.
FIG. 13 is a diagram illustrating stacking of display areas to represent pixel irregularity data in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
In accordance with the present invention, a device authentication server 108 ( FIG. 1 ) authenticates a computing device 102 using data representing pixel irregularities of a display of device 102 . Pixel irregularities include dead pixels, hot pixels, and stuck pixels. These pixel irregularities differ between even otherwise identical devices since pixel failure in displays is a relatively random event.
In most displays in use today, a pixel is instructed to display a given color by writing three (3) bytes to the pixel: one byte representing an amount of red, one byte representing an amount of green, and one byte representing an amount of blue. Such bytes are frequently represented in human-readable form as six (6) hexadecimal digits: the first two (2) representing a red value, the middle two (2) representing a green value, and the last two (2) representing a blue value. For example, “FF0000” represents fully bright red, “00FF00” represents fully bright green, and “0000FF” represents fully bright blue.
While RGB color schemes are described herein, it should be appreciated that other color schemes are amenable to device identification in the manner described herein.
Each pixel typically includes three (3) sub-pixels: one red, one green, and one blue, each of which is controlled by a respective byte in an RGB color value. Dead pixels are pixels that appear black regardless of red, green, and blue (RGB) or other color values written to the pixel. In effect, a dead pixel is a pixel that displays “000000” regardless of what RGB value is written to the pixel. Hot pixels are pixels that appear white, i.e., display “FFFFFF”, regardless of the RGB value written to the pixel.
Stuck pixels are pixels in which only one or more sub-pixels are dead or hot. For example, if a pixel has a dead red sub-pixel, the first byte of the displayed color will always be “00” regardless of the first byte of the RGB value written to the pixel-writing “888888” to the pixel results in display of the color “008888”, thus erroneously displaying a color with a hue that is less red than intended. Similarly, if a pixel has a hot green sub-pixel, the second byte of the displayed color will always be “FF” regardless of the second byte of the RGB value written to the pixel-writing “888888” to the pixel results in display of the color “88FF88”, thus erroneously displaying a color with a hue that is more green than intended.
A stuck pixel can include three (3) failed pixels. For example, if the red and blue sub-pixels are dead and the green sub-pixel is hot, the pixel will display “00FF00” regardless of the RGB value written to the pixel and will therefore always display fully bright green, giving the appearance of being “stuck” on green. In fact, dead and hot pixels can be considered special cases of stuck pixels.
Such pixel irregularities result from failure of display hardware in which data storage cells for given sub-pixels fail and become either fully on or fully off. Such hardware failures are due to IC or other digital logic hardware irregularities during manufacture and therefore happen largely randomly in the field. Accordingly, a map of pixel irregularities for a given device can be unique, even among nearly identical devices.
Device authentication system 100 ( FIG. 1 ) includes device 102 , a server 106 , and a device authentication server 108 that are connected to one another through a wide area computer network 104 , which is the Internet in this illustrative embodiment. Device 102 can be any of a number of types of networked computing devices, including smart phones, tablets, netbook computers, laptop computers, and desktop computers. Server 106 is a server that provides services to remotely located devices such as device 102 but that is configured to require authentication of device 102 prior to providing those services. Device authentication server 108 is a server that authenticates devices, sometimes on behalf of other computers such as server 106 .
In this illustrative embodiment, a map of pixel irregularities of device 102 are combined with other attributes of device 102 to uniquely identify and authenticate device 102 . Such other attributes include hardware and system configuration attributes of device 102 that make up an internal state of device 102 . Device attributes are described briefly to facilitate understanding and appreciation of the present invention.
Known device record 500 ( FIG. 5 ) includes device attributes 504 , both of which are described in greater detail below. Each device attribute 504 includes an identifier 506 and a value 508 . Other than maps of pixel irregularities, examples of device attributes of device 102 include a serial number of a storage device within device 102 and detailed version information regarding an operating system executing within device 102 . In the example of a serial number of a storage device, identifier 506 specifies the serial number of a given storage device (such as “C:” or “/dev/sda1”) as the particular information to be stored as value 508 , and value 508 stores the serial number of the given storage device of device 102 .
In the example of maps of pixel irregularities, value 508 will be in the form of pixel map 400 ( FIG. 4 ) that is described in greater detail below in the context of registration of device 102 for subsequent authentication.
For subsequent authentication of device 102 , registration in the manner illustrated in transaction flow diagram 200 ( FIG. 2 ) retrieves tag data from device 102 .
In step 202 , device 102 sends a request for registration to device authentication server 108 . The request can be in the form of a URL specified by the user of device 102 using a web browser 1120 ( FIG. 11 ) executing in device 102 and conventional user interface techniques involving physical manipulation of user input devices 1108 . Web browser 1120 and user input devices 1108 and other components of device 102 are described in greater detail below.
In step 204 ( FIG. 2 ), device authentication server 108 sends a request to device 102 for device attributes of device 102 .
The request sent to device 102 includes content that causes web browser 1120 ( FIG. 11 ) of device 102 to gather attribute data representing hardware and other configuration attributes of device 102 . In one embodiment, a web browser plug-in 1122 is installed in device 102 and, invoked by web browser 1120 , processes the content of the web page to gather the attribute data in step 206 . In other embodiments, the attribute data can be gathered in step 206 by other forms of logic of device 102 , such as DDK generator 1140 installed in device 102 . The various elements of device 102 and their interaction are described more completely below.
The content that causes web browser 1120 ( FIG. 11 ) of device 102 to gather attribute data representing hardware and other configuration attributes of device 102 includes extraction logic 510 ( FIG. 5 ) for each of the attributes web browser 1120 ( FIG. 11 ) is to gather. In an alternative embodiment, DDK generator 1140 already includes extraction logic for all attributes and device 102 receives data identifying the particular attributes requested by device authentication server 108 . Extraction logic 510 ( FIG. 5 ) defines the manner in which a client device is to extract data to be stored as value 508 of device attribute 504 .
In step 206 , device 102 writes test pixel data to each and every pixel of an LED monitor 1111 ( FIG. 11 ), reads the data stored by each pixel, and compares the data written to the data read to identify failed sub-pixels. For example, device 102 can write RGB values in which no byte is either “FF” or “00” and determining which sub-pixels store sub-pixel values that are either “FF” or “00”. RGB values of “AAAAAA” and “555555” have alternating “0” and “1” bits and are good candidates for RGB values to use for testing for sub-pixel irregularities. Alternatively, device 102 can test separately by writing “FFFFFF” and “000000” to each pixel in separate passes. Writing “FFFFFF” to a pixel can test for dead sub-pixels, and writing “000000” to a pixel can test for hot sub-pixels.
While many displays do not support reading of pixel data displayed by the monitor, some LED monitors currently support such reading. In the future, reading of pixel data can be much more widely supported. In addition, while only fully on and fully off sub-pixels are described herein as pixel irregularities, it should be appreciated that monitors can make detection of other irregularities available and can then be used for device identification in the manner described herein.
Since writing to pixels causes at least properly functioning pixels to change color, writing and reading all pixels at once might produce a visible flash that could be annoying or confusing to the user. In some embodiments, no more than a few pixels are written and read at any time. The particular pixels written to at any one time are spread widely throughout the display to avoid more than a single pixel flashing in any sizable area of the display at any time. Any visible artifacts of a few individual pixels flashing at a time are much less noticeable.
In one embodiment, device 102 represents the map of pixel irregularities in a pixel map 1150 ( FIG. 11 ) that is generally of the form shown as pixel map 400 ( FIG. 4 ). Pixel map 400 includes a number of pixel records 402 , each of which represents a pixel irregularity. The particular pixel represented by pixel record 402 ( FIG. 4 ) is sometimes referred to as “the subject pixel” in the context of FIG. 4 .
Irregularity 404 represents the particular irregularity of the subject pixel. In this illustrative embodiment, irregularity 404 represents irregularity types for each sub-pixel: red, green, and blue. The irregularity types include dead, hot, and none. A dead pixel would be represented as red=dead, green=dead, and blue=dead. A pixel in which only the blue sub-pixel is hot would be represented as red=none, green=none, and blue=hot. This can be represented in only six (6) bits, each pair representing one of the three irregularities for a respective sub-pixel: e.g., “00” for none, “01” for dead”, and “10” for hot, the first two bits for red, the second two bits for blue, and the last 2 bits for green.
X 406 and Y 408 specify the particular location of the subject pixel in LED display 1111 ( FIG. 11 ). Thus, X 406 and Y 408 uniquely identify the subject pixel.
As a whole, pixel map 400 represents a complete map of pixel irregularities of a given display. It should be appreciated that there are many ways to represent a map of pixel irregularities of a given display.
It is not necessary that the map be complete. However, it is preferred that the particular representation of a map of pixel irregularities be one from which device authentication server 108 can assess a rate of change in pixel irregularities overall over time. Sub-pixels do not heal themselves. Accordingly, over time, a device's map of pixel irregularities should not show fewer irregularities or the absence of previously observed irregularities. In addition, the observed rate of growth of pixel irregularities should increase within a range of reasonably expected rates of growth. The representation of a map of pixel irregularities should allow assessment of an observed rate of growth.
One example of such a representation gathered in step 206 ( FIG. 2 ) is illustrated by logic flow diagram 206 ( FIG. 7 ). In step 702 , device 102 writes test data to all pixels in the manner described above. In step 704 , device 102 reads data stored at all pixels. As discussed above, the writing and reading can be done in batches of less than the entirety of the display.
In step 706 , device 102 divides the entirety of the read pixel data into areas of equal size. For example, LED monitor 1111 ( FIG. 12 ) is divided into 16 areas 1202 of equal size.
Loop step 708 ( FIG. 7 ) and next step 712 define a loop in which device 102 processes each of areas 1202 ( FIG. 12 ) according to step 710 ( FIG. 7 ). During each iteration of the loop of steps 708 - 712 , the particular area 1202 processed by device 102 A is sometimes referred to as the subject area.
In step 710 , device 102 builds an array specifying sub-pixel irregularities in the subject area. FIG. 13 shows illustrative examples of such arrays as arrays 1302 A-C. In this illustrative example, the test data written to all pixels in step 702 ( FIG. 7 ) is “AAAAAA”, alternating 1s and 0s in binary. In array 1302 A, data read from a given location of the subject area is “AAAAAA” and therefore contains no sub-pixel irregularities. Such is represented in array 1302 A at a location corresponding to the given pixel location by R=0, G=0, and B=0, indicating no sub-pixel irregularities, wherein 0 indicates no irregularity. In array 1302 B, data read from the given location of the subject area is “000000” and therefore represents a dead pixel. Such is represented in array 1302 B at a location corresponding to the given pixel location by R=1, G=1, and B=1, indicating three dead sub-pixels, wherein 1 indicates a dead sub-pixel. In array 1302 C, data read from the given location of the subject area is “AA00FF” and therefore represents a stuck pixel in which the green sub-pixel is dead and the blue sub-pixel is hot. Such is represented in array 1302 C at a location corresponding to the given pixel location by R=0, G=1, and B=2, indicating three dead sub-pixels, wherein 2 indicates a hot sub-pixel.
After the subject array is built and represents any and all sub-pixel irregularities of the subject area, processing by device 102 transfers through next step 712 to loop step 708 in which device 102 processes the next area according to the loop of steps 708 - 712 . When all areas have been processed according to step 710 , processing by device 102 transfers from loop step 708 to step 714 .
In step 714 , device 102 sums the arrays built in the multiple performances of step 710 . Device 102 sums arrays 1302 A-C ( FIG. 13 ) by summing the sub-pixel values at corresponding locations and storing the summed values in a corresponding location in array 1304 . For example, summing the sub-pixel values of arrays 1302 A-C described above, the sub-pixel values for the same location within array 1304 is R=1, G=2, B=3.
In step 716 ( FIG. 7 ), device 102 encodes array 1304 in a lossless image format. Array 1304 is already in a form that can readily be represented as a bitmap image. However, a number of losslessly compressed image formats are known and can be used to represent array 1304 using significantly less data. Lossless compression preserves all pixel data perfectly such that it can be retrieved after decompression. In this illustrative example of such a losslessly compressed image format is the known PNG (portable network graphics) format. After step 716 , processing according to logic flow diagram 206 , and therefore step 206 ( FIG. 2 ), completes.
The result is that pixel map 1150 ( FIG. 11 ) is in the form of a PNG image and is therefore lightweight for transportation through computer networks. It is preferred that the number of areas 1202 ( FIG. 12 ) of equal size is limited in number to no more than 128. Accordingly, the sum of sub-pixel states (0-2 in value) will never exceed the maximum value of a sub-pixel—256 (“FF” in hexadecimal).
In this illustrative embodiment, device 102 —in particular, web browser plug-in 1122 ( FIG. 11 ) or DDK generator 1140 —encrypts the attribute data using a public key of device authentication server 108 and public key infrastructure (PKI) in step 206 , thereby encrypting the attribute data such that it can only be decrypted by device authentication server 108 .
In step 208 ( FIG. 2 ), device 102 sends the attribute data that was gathered in step 206 to device authentication server 108 .
In step 210 , device authentication logic 1020 ( FIG. 10 ) of device authentication server 108 creates a device registration record for device 102 from the received attribute data. Device authentication server 108 creates a device registration record in the form of known device record 500 ( FIG. 5 ) for device 102 by creating a globally unique identifier for device 102 as device identifier 502 ( FIG. 5 ) and storing the values of the respective attributes, including the tag data, received in step 208 ( FIG. 2 ) as value 508 ( FIG. 5 ) in respective device attributes 504 . Known device record 500 is described more completely below in greater detail.
In step 212 ( FIG. 2 ), device authentication server 108 sends a report of successful registration to device 102 , providing device identifier 502 ( FIG. 5 ) of device 102 for subsequent identification. After step 212 ( FIG. 2 ), processing according to transaction flow diagram 200 completes and device 102 is registered for subsequent authentication with device authentication server 108 .
Known device record 500 ( FIG. 5 ) is a registration record and, in this illustrative example, represents registration of device 102 . Known device record 500 includes a device identifier 502 and a number of device attributes 504 which are described briefly above. Each device attribute 504 includes an identifier 506 specifying a particular type of information and a value 508 representing the particular value of that type of information from device 102 . For example, if identifier 506 specifies a serial number of a given storage device, value 514 stores the serial number of that storage device within device 102 . Similarly, if identifier 506 specifies pixel irregularities for a display of device 102 , value 508 stores data representing the map of pixel irregularities.
In this illustrative embodiment, value 508 stores the tag data in the form of pixel map 400 ( FIG. 4 ) or in a lossless image format as described above. In alternative embodiments, value 508 ( FIG. 5 ) can store an abstraction of the pixel map. For example, value 508 can store a hash of the pixel map.
Device attribute 504 ( FIG. 5 ) also includes extraction logic 510 , comparison logic 512 , alert logic 514 , and adjustment logic 516 . The particular device attribute represented by device attribute 504 is sometimes referred to as “the subject device attribute” in the context of FIG. 5 .
Extraction logic 510 specifies the manner in which the subject device attribute is extracted by device 102 . Logic flow diagram 206 ( FIG. 7 ), described above, is an example of extraction logic 510 for a map of pixel irregularities.
Comparison logic 512 specifies the manner in which the subject device attribute is compared to a corresponding device attribute to determine whether device attributes match one another. An example of comparison logic 512 is described more completely below in conjunction with logic flow diagram 610 ( FIG. 8 ).
Alert logic 514 can specify alerts of device matches or mismatches or other events. Examples of alert logic 514 include e-mail, SMS messages, and such to the owner of device 102 and/or to a system administrator responsible for proper functioning of device 102 .
Adjustment logic 516 specifies the manner in which the subject device attribute is to be adjusted after authentication. For example, if the map of pixel irregularities received for authentication indicates further pixel deterioration (greater irregularities) than indicated by the map of pixel irregularities already stored in value 508 , adjustment logic 516 can cause value 508 to be updated to store the newly received map of pixel irregularities.
Device attribute 504 is shown to include the elements previously described for ease of description and illustration. However, it should be appreciated that a device attribute 504 for a given device can include only identifier 506 and value 508 , while a separate device attribute specification can include extraction logic 510 , comparison logic 512 , alert logic 514 , and adjustment logic 516 . In addition, all or part of extraction logic 510 , comparison logic 512 , alert logic 514 , and adjustment logic 516 can be common to attributes of a given type and can therefore be defined for the given type.
Transaction flow diagram 300 ( FIG. 3 ) illustrates the use of device authentication server 108 to authenticate device 102 with server 106 .
In step 302 , device 102 sends a request for a log-in web page to server 106 by which the user can authenticate herself. The request can be in the form of a URL specified by the user of device 102 using web browser 1120 ( FIG. 11 ) and conventional user interface techniques involving physical manipulation of user input devices 1108 .
In step 304 ( FIG. 3 ), server 106 sends the web page that is identified by the request received in step 302 . In this illustrative example, the web page sent to device 102 includes content that defines a user interface by which the user of device 102 can enter her authentication credentials, such as a user name and associated password for example.
In step 306 , web browser 1120 ( FIG. 11 ) of device 102 executes the user interface and the user of device 102 enters her authentication credentials, e.g., by conventional user interface techniques involving physical manipulation of user input devices 1108 . While the user is described as authenticating herself in this illustrative example, it should be appreciated that device 102 can be authenticated without also requiring that the user of device 102 is authenticated.
In step 308 ( FIG. 3 ), device 102 sends the entered authentication credentials to server 106 . In this illustrative embodiment, device 102 also sends an identifier of itself along with the authentication credentials. Server 106 authenticates the authentication credentials in step 310 , e.g., by comparison to previously registered credentials of known users. If the credentials are not authenticated, processing according to transaction flow diagram 300 terminates and the user of device 102 is denied access to services provided by server 106 . Conversely, if server 106 determines that the received credentials are authentic, processing according to transaction flow diagram 300 continues.
In step 312 ( FIG. 3 ), server 106 sends a request to device authentication server 108 for a session key using the device identifier received with the authentication credentials.
In response to the request, device authentication server 108 generates and cryptographically signs a session key. Session keys and their generation are known and are not described herein. In addition, device authentication server 108 creates a device key challenge and encrypts the device key challenge using a public key of device 102 and PKI.
To create the device key challenge, device authentication server 108 retrieves the known device record 500 ( FIG. 5 ) representing device 102 using the received device identifier and comparing it to device identifier 502 . The device key challenge specifies all or part of one or more of device attribute 504 to be included in the device key and is described in greater detail below.
In step 316 ( FIG. 3 ), device authentication server 108 sends the signed session key and the encrypted device key challenge to server 106 .
In step 318 , server 106 sends a “device authenticating” page to device 102 along with the device key challenge. The “device authenticating” page includes content that provides a message to the user of device 102 that authentication of device 102 is underway and content that causes device 102 to produce a dynamic device key in the manner specified by the device key challenge.
The device key challenge causes web browser 1120 ( FIG. 11 ) of device 102 to generate a device identifier, sometimes referred to herein as a dynamic device key (DDK) for device 102 , e.g., dynamic device key 1142 . In one embodiment, a web browser plug-in 1122 is installed in client device 102 and, invoked by web browser 1120 , processes the content of the web page to generate the DDK. In other embodiments, DDK 1142 of device 102 can be generated by other forms of logic of device 102 , such as DDK generator 1140 , which is a software application installed in device 102 .
The device key challenge specifies the manner in which DDK 1142 is to be generated from the attributes of device 102 represented in device attributes 504 ( FIG. 5 ). The challenge specifies a randomized sampling of attributes of device 102 , allowing the resulting DDK 1142 to change each time device 102 is authenticated. There are a few advantages to having DDK 1142 represent different samplings of the attributes of device 102 . One is that any data captured in a prior authentication of device 102 cannot be used to spoof authentication of device 102 using a different device when the challenge has changed. Another is that, since only a small portion of the attributes of device 102 are used for authentication at any time, the full set of attributes of device 102 cannot be determined from one, a few, several, or even many authentications of device 102 .
The device key challenge specifies items of information to be collected from hardware and system configuration attributes of device 102 and the manner in which those items of information are to be combined to form DDK 1142 . In this embodiment, the challenge specifies one or more attributes related to pixel irregularity data of device 102 .
To provide greater security, DDK 1142 includes data representing the pixel irregularity data obfuscated using a nonce included in the challenge. While use of randomized parts of the pixel irregularity data precludes capture of any single DDK to be used in subsequent authentication, use of the nonce thwarts collection of randomized parts of the pixel irregularity data over time to recreate enough of tag log 400 ( FIG. 4 ) to spoof authentication in response to a given challenge.
In step 320 ( FIG. 3 ), device 102 gathers pixel irregularity data for inclusion in the DDK according to the device key challenge. In this illustrative embodiment, device 102 performs step 320 in a manner analogous to that described above with respect to logic flow diagram 206 (FIG. 7 ).
Once DDK 1142 ( FIG. 11 ) is generated according to the received device key challenge, device 102 encrypts DDK 1142 using a public key of device authentication server 108 and PKI.
In step 322 ( FIG. 3 ), device 102 sends the encrypted dynamic device key to server 106 , and server 106 sends the encrypted dynamic device key to device authentication server 108 in step 324 .
In step 326 , device authentication logic 1020 of device authentication server 108 decrypts and authenticates the received DDK. Step 326 is shown in greater detail as logic flow diagram 326 ( FIG. 6 ).
In step 602 , device authentication logic 1020 identifies device 102 . In this illustrative embodiment, the received DDK includes a device identifier corresponding to device identifier 502 ( FIG. 5 ). Device authentication logic 1020 identifies device 102 by locating a known device record 500 in which device identifier 502 matches the device identifier of the received DDK.
In test step 604 ( FIG. 6 ), device authentication logic 1020 determines whether device 102 is identified. In particular, device authentication logic 1020 determines whether a known device record with a device identifier matching the device identifier of the received DDK is successfully found in known device data 1030 . If so, processing transfers to step 606 . Otherwise, processing transfers to step 616 , which is described below.
In step 606 , device authentication logic 1020 retrieves the known device record 500 ( FIG. 5 ) for the identified device, e.g., device 102 , using the identifier determined in step 602 ( FIG. 6 ).
In step 608 , device authentication logic 1020 authenticates the received DDK using the retrieved device record 500 ( FIG. 5 ). Device authentication logic 1020 authenticates by applying the same device key challenge sent in step 318 ( FIG. 3 ) to the known device record 500 ( FIG. 5 ) that corresponds to the identified device. In this illustrative embodiment, the device key challenge produces a DDK in which a portion of the DDK generated from non-interactive attributes can be parsed from a portion generated from interactive attributes, such that device 102 can be authenticated separately from the user of device 102 .
In test step 610 ( FIG. 6 ), device authentication logic 1020 determines whether the received DDK authenticates device 102 by comparing the resulting DDK of step 608 to the received DDK. In this illustrative embodiment, device authentication logic 1020 uses comparison logic 512 ( FIG. 5 ) for each of the device attributes 504 included in the device key challenge.
The portion of step 320 in which device authentication logic 1020 determines whether the pixel irregularity portion of the dynamic device key matches is shown in greater detail as logic flow diagram 610 ( FIG. 8 ).
In step 802 , device authentication logic 1020 determines the an amount by which the pixel irregularity data from the dynamic device key exceeds the reference pixel irregularity data from known device record 500 .
In test step 804 ( FIG. 8 ), device authentication logic 1020 determines whether the amount determined in step 802 is negative, i.e., that the pixel irregularity data from the dynamic device key is less irregular than the reference pixel irregularity data from known device record 500 . LED displays are presumed to not be able to heal; accordingly, device 102 determines that the pixel irregularity data does not match if the amount is negative. Conversely, if the amount is non-negative, processing transfers to test step 806 .
In test step 806 ( FIG. 8 ), device authentication logic 1020 determines whether the amount determined in step 802 exceeds a predetermined reasonable rate of deterioration. To make such a determination, the reference pixel irregularity data from known device record 500 is associated with a time stamp specifying when the reference pixel irregularity data was first stored in known device record 500 . Accordingly, device authentication logic 1020 can determine over what time span the pixel irregularities of device 102 is reported to have grown.
If the amount determined in step 802 exceeds the predetermined reasonable rate of deterioration, device authentication logic 1020 determines that the pixel irregularity data does not match. Conversely, if the amount determined in step 802 does not exceed the predetermined reasonable rate of deterioration, device authentication logic 1020 determines that the pixel irregularity data match.
In this illustrative embodiment, the matching of the pixel irregularity data is not dispositive of whether the dynamic device key as a whole matches. Instead, the match or lack thereof influences an overall estimated likelihood that device 102 is, in fact, the device represented by known device record 500 ( FIG. 5 ).
If the received DDK does not authenticate device 102 , processing transfers to step 616 and authentication fails or, alternatively, to step 314 ( FIG. 3 ) in which device authentication logic 1020 sends another device key challenge to re-attempt authentication. If the received DDK authenticates device 102 , processing transfers to step 612 .
In step 612 , device authentication logic 1020 determines that device 102 is successfully authenticated.
In step 614 ( FIG. 6 ), device authentication logic 1020 applies adjustment logic 516 ( FIG. 5 ) of each of device attributes 504 uses to generate the received DDK. For example, adjustment logic 516 can specify that, since device 102 is authenticated, device authentication logic 1020 incorporates the newly received pixel irregularity data into value 508 . After step 614 ( FIG. 6 ), processing according to logic flow diagram 326 , and therefore step 326 , completes.
As described above, authentication failure at either of test steps 604 and 610 transfers processing to step 616 . In step 616 , device authentication logic 1020 determines that device 102 is not authentic, i.e., that authentication according to logic flow diagram 326 fails.
In step 618 , device authentication logic 1020 logs the failed authentication and, in step 620 , applies alert logic 514 ( FIG. 5 ) to notify various entities of the failed authentication. After step 620 ( FIG. 6 ), processing according to logic flow diagram 326 , and therefore step 326 , completes.
In step 328 ( FIG. 3 ), device authentication server 108 sends data representing the result of authentication of device 102 to server 106 .
In step 330 , server 106 determines whether to continue to interact with device 102 and in what manner according to the device authentication results received in step 328 .
Server computer 106 is shown in greater detail in FIG. 9 . Server 106 includes one or more microprocessors 902 (collectively referred to as CPU 902 ) that retrieve data and/or instructions from memory 904 and execute retrieved instructions in a conventional manner. Memory 904 can include generally any computer-readable medium including, for example, persistent memory such as magnetic and/or optical disks, ROM, and PROM and volatile memory such as RAM.
CPU 902 and memory 904 are connected to one another through a conventional interconnect 906 , which is a bus in this illustrative embodiment and which connects CPU 902 and memory 904 to network access circuitry 912 . Network access circuitry 912 sends and receives data through computer networks such as wide area network 104 ( FIG. 1 ).
A number of components of server 106 are stored in memory 904 . In particular, web server logic 920 and web application logic 922 , including authentication logic 924 , are all or part of one or more computer processes executing within CPU 902 from memory 904 in this illustrative embodiment but can also be implemented using digital logic circuitry.
Web server logic 920 is a conventional web server. Web application logic 922 is content that defines one or more pages of a web site and is served by web server logic 920 to client devices such as device 102 . Authentication logic 924 is a part of web application logic 922 that carries out device authentication in the manner described above.
Device authentication server 108 is shown in greater detail in FIG. 10 . Device authentication server 108 includes one or more microprocessors 1002 (collectively referred to as CPU 1002 ), memory 1004 , a conventional interconnect 1006 , and network access circuitry 1012 , which are directly analogous to CPU 902 ( FIG. 9 ), memory 904 , conventional interconnect 906 , and network access circuitry 912 , respectively.
A number of components of device authentication server 108 ( FIG. 10 ) are stored in memory 1004 . In particular, device authentication logic 1020 is all or part of one or more computer processes executing within CPU 1002 from memory 1004 in this illustrative embodiment but can also be implemented using digital logic circuitry. Known device data 1030 is data stored persistently in memory 1004 and includes known device records such as known device record 500 ( FIG. 5 ) for all devices that can be authenticated by device authentication logic 1020 . In this illustrative embodiment, known device data 1030 is organized as all or part of one or more databases.
Device 102 is a personal computing device and is shown in greater detail in FIG. 11 . Device 102 includes one or more microprocessors 1102 (collectively referred to as CPU 1102 ) that retrieve data and/or instructions from memory 1104 and execute retrieved instructions in a conventional manner. Memory 1104 can include generally any computer-readable medium including, for example, persistent memory such as magnetic and/or optical disks, ROM, and PROM and volatile memory such as RAM.
CPU 1102 and memory 1104 are connected to one another through a conventional interconnect 1106 , which is a bus in this illustrative embodiment and which connects CPU 1102 and memory 1104 to one or more input devices 1108 , output devices 1110 , and network access circuitry 1112 . Input devices 1108 can include, for example, a keyboard, a keypad, a touch-sensitive screen, a mouse, a microphone, and one or more cameras. Input devices 1108 detect physical manipulation by a human user and, in response to such physical manipulation, generates signals representative of the physical manipulation and sends the signals to CPU 1102 . Output devices 1110 can include, for example, a display—such as a liquid crystal display (LCD)—and one or more loudspeakers. LED monitor 1111 is an LED monitor used to display visual data to the user. Network access circuitry 1112 sends and receives data through computer networks such as wide area network 104 ( FIG. 1 ).
A number of components of device 102 are stored in memory 1104 . In particular, web browser 1120 , operating system 1130 , DDK generator 1140 , and social networking application 1144 are each all or part of one or more computer processes executing within CPU 1102 from memory 1104 in this illustrative embodiment but can also be implemented using digital logic circuitry. As used herein, “logic” refers to (i) logic implemented as computer instructions and/or data within one or more computer processes and/or (ii) logic implemented in electronic circuitry.
Web browser plug-ins 1122 are each all or part of one or more computer processes that cooperate with web browser 1120 to augment the behavior of web browser 1120 . The manner in which behavior of a web browser is augmented by web browser plug-ins is conventional and known and is not described herein.
Operating system 1130 is a set of programs that manage computer hardware resources and provide common services for application software such as web browser 1120 , web browser plug-ins 1122 , and DDK generator 1140 . Operating system 1130 includes a monitor driver 1132 that communicates at a device level with LED monitor 1111 to write pixel data to, and read pixel data from, LED monitor 1111 .
DDK generator 1140 facilitates authentication of device 102 in the manner described above.
Pixel map 1150 is data stored persistently in memory 1104 and each can be organized as all or part of one or more databases. Pixel map 1150 is generally of the structure of pixel map 400 ( FIG. 4 ).
The above description is illustrative only and is not limiting. The present invention is defined solely by the claims which follow and their full range of equivalents. It is intended that the following appended claims be interpreted as including all such alterations, modifications, permutations, and substitute equivalents as fall within the true spirit and scope of the present invention. | A device authentication server authenticates a remotely located device using data representing pixel irregularities of a display of the device. Since each display will deteriorate in a unique and randomized way, a unique mapping of pixel irregularities of a display of a device will be unique. By combining unique map of pixel irregularities of a display of the remotely located device, the device can be distinguished from similar devices when other attributes alone are insufficient to uniquely identify the device. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Section 371 of International Application No. PCT/EP2006/001313, filed Feb. 14, 2006, which was published in the German language on Aug. 31, 2006, under International Publication No. WO 2006/089660 A2 and the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method for purifying marine collagen, especially for enhancing the smell and appearance of marine collagen.
[0003] The invention further relates to a method for the production of porous sponges of marine collagen which are suitable in particular for medical purposes.
[0004] Collagen is a biodegradable as well as biocompatible protein which is used as a starting material for manifold applications in the food industry, in the pharmaceutical and cosmetic industries as well as in medicine.
[0005] “Marine collagen” is understood to mean collagen isolated from marine organisms, that is, organisms living in the sea, especially from members of the Porifera strain, preferably from Chondrosia reniformis.
[0006] A large number of collagen products are known and being utilized in medicine. Such products include, for example, sponges, fibers or membranes.
[0007] The vast majority of these products is manufactured from collagen which is produced from the connective tissue, the skin, the bones, or the tendons of mammals, for example from cattle, horses or pigs. The essential disadvantages of these products are to be seen in the facts that:
[0008] in most cases, a young animal has to be used as the source for the collagen in order to obtain a sufficient yield of collagen;
[0009] the collagen obtained is in most cases soluble both in acid media as well as in basic media, which necessitates an additional crosslinking reaction (physically, by heat treatment, or chemically, by using bifunctional substances) in order to enhance the mechanical properties of the collagen and its stability in liquid media;
[0010] there is a risk of contamination with bovine spongiform encephalopathy (BSE).
[0011] As an alternative to producing collagen from mammals, International patent application publication WO 01/64046 describes a method for isolating collagen from marine sponges of the genus Chondrosia reniformis (Porifera, Demospongiae).
[0012] In this method, fresh sponge starting material is imbibed in alcohol and then washed with water, and an extracting agent is added thereto, preferably at a pH of 7-12. The resultant collagen extract is processed by increasing the pH of the suspension to a value of 8-11, stirring, centrifuging, subsequently lowering the pH value of the supernatant, as well as centrifuging and isolating the precipitate.
[0013] The sponge collagen obtainable by this method does, however, have disadvantages consisting essentially in that:
[0014] the collagen solution has a dirty appearance;
[0015] the collagen is microbiologically impure; and
[0016] products from this sponge collagen have an unpleasant smell.
BRIEF SUMMARY OF THE INVENTION
[0017] The task underlying the present invention thus was to eliminate the above-mentioned disadvantages of marine collagen and to provide collagen from marine organisms, which is also suitable for the manufacture of products for medicinal purposes.
[0018] This task is solved by a method wherein a collagen precipitate is purified by using chemical treatment steps, thereby enhancing the smell and appearance thereof. The purified collagen can subsequently be processed into porous sponges by lyophilization.
[0019] According to the present invention, the method for purifying marine collagen encompasses treating a collagen precipitate, as obtainable, for example, according to the method described in WO 01/64046, with hydrogen peroxide in aqueous solutions at different pH values.
[0020] To this end, the moisture of the collagen precipitate should initially be adjusted to a content of 70 to 95% by weight, preferably to a content of 80 to 90% by weight. This can be accomplished by wringing the collagen precipitate under pressure or by centrifugation, in order to reduce the moisture content of the collagen precipitate to the desired content, if necessary.
[0021] The collagen precipitate is then suspended in an aqueous H 2 O 2 solution containing 0.1 to 1% (v/v), preferably 0.5% (v/v), of H 2 O 2 . Then the pH of the collagen suspension is adjusted to a value of from 11 to 13. This causes the collagen to dissolve.
[0022] Following incubation of the collagen with H 2 O 2 under alkaline conditions, the collagen solution is filtered to remove insoluble components. Thereafter, the collagen is precipitated from the solution by adding a suitable water-miscible organic solvent to the solution.
[0023] The collagen precipitate is filtered off, and its moisture content is readjusted to 70-95% by weight, preferably 80 to 90% by weight. Then, the collagen is again dissolved in an aqueous H 2 O 2 solution, which has a content of H 2 O 2 of 0.1 to 1% (v/v), preferably of 0.5% (v/v), and the pH of this collagen solution is adjusted to a value of from 5 to 7, so that the collagen may then be used for the production of sponges, membranes or fibers for medical purposes.
[0024] Adjustment of the pH to a value of from 11 to 13 is preferably accomplished with NaOH, but it may also be accomplished with other alkali hydroxides or alkaline earth hydroxides, such as KOH, Ca(OH) 2 or Mg(OH) 2 .
[0025] As water-miscible organic solvents, ethanol and isopropanol are preferred. Precipitation is preferably performed at a ratio of water to ethanol which is between 1:2 and 1:3.
[0026] Neutralization of the collagen solution to a pH of 5 to 7 may be accomplished by reducing the pH value by adding organic acids, e.g., formic acid, acetic acid, citric acid, ascorbic acid, propionic acid, lactic acid, or inorganic acids, such as hydrochloric acid, phosphoric acid or sulfuric acid. Preferably, the pH value is adjusted by addition of 5 N hydrochloric acid.
[0027] The advantages of the method according to the invention are:
[0028] a high yield in protein extraction;
[0029] a sterile collagen which is free of bacteria;
[0030] a BSE-free collagen since Porifera have no neural structures;
[0031] a collagen with a pleasing appearance which does not look dirty;
[0032] a collagen without unpleasant smell;
[0033] a collagen which is insoluble in acid media and which does not necessitate an additional crosslinking reaction in order to improve its mechanical properties and stability in liquids; and
[0034] a collagen which can be used for the production of dressings for wound healing or as a support in tissue regeneration.
[0035] On account of its advantages, the collagen purified by using the method according to the present invention is particularly suitable for the manufacture of products for medical purposes.
[0036] Therefore, the collagen purified using the method according to the present invention, as well as the use thereof for the manufacture of porous sponges, fiber material or membranes, are also subject matters of the present invention.
[0037] The present invention thus also relates to methods for the production of porous sponges from the purified marine collagen.
[0038] Porous collagen sponges may be produced by a method wherein a solution obtained according to the method of the present invention is deep-frozen and freeze-dried after the collagen solution has either been foamed up by vigorous shaking/stirring or after the air contained in the collagen solution has been removed in vacuo, in order to produce sponges with smaller pores. The collagen solution preferably contains collagen at a concentration of 0.5 to 5% by weight.
[0039] By using appropriate molds, in which the collagen solution or the collagen foam is frozen, it is possible to produce porous collagen foams of any shape.
[0040] Collagen sponges with further enhanced properties, especially with a view to their medical application, can be obtained by acid treatment of the collagen sponges after these have been freeze-dried. Acid treatment is performed with inorganic acids, preferably by immersing the sponge in an 0.1 NHCl solution. Thereafter, the acid-treated sponge can be dehydrated by deep-freezing and freeze-drying, or by immersing in ethanol and air-drying.
[0041] Employing the method according to the present invention for producing collagen sponges, it is possible also to produce porous collagen sponges with antimicrobial properties. To this end, an antimicrobially active substance can be added to the collagen suspension prior to deep-freezing. A preferred antimicrobially active substance is silver sulfadiazine, which is added in an amount of 1% by weight, relative to the amount of collagen in the suspension.
[0042] As an alternative to the afore-described approach, the porous collagen foams can be immersed, after the acid treatment, in a solution containing an antimicrobially active substance. Subsequently, the collagen sponge can be dehydrated by freeze-drying or, if the antimicrobially active substance is insoluble in ethanol, by immersing in ethanol and subsequent air-drying.
[0043] Additional subject matters of the present invention are therefore the porous collagen sponges produced by the aforementioned method and the use of the sponges for the manufacture of products for medicinal purposes, such as wound dressings.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The invention will now be described in greater detail with reference to the following specific, non-limiting examples.
Example 1
Method for Purifying Sponge Collagen
[0045] A collagen precipitate precipitated in an acid medium (pH 3), which had been obtained in accordance with the method described in WO 01/64046, was separated from the medium by filtration and wrung out under pressure until a residual moisture content of approximately 84% by weight was obtained. The collagen fibers obtained in this manner were freeze-dried for storage at a temperature of approx.-20° C.
[0046] 121 g of the frozen collagen fibers were suspended in 1300 ml of aqueous 0.5% (v/v) H 2 O 2 solution while stirring for 2 hours. Then, the pH of the solution was adjusted to a value of 12.4 with a 5N solution of NaOH, in order to dissolve the collagen fibers. The resulting collagen solution was filtered to remove insoluble components and then poured into 2600 ml ethanol (conc. 98%), while stirring vigorously. The collagen thereby precipitated was of a white or slightly yellowish color and had a fibrous appearance.
[0047] The collagen fibers were freed from the medium by filtration, wrung out under pressure or by centrifugation and subsequently homogenously suspended in 300 ml of an aqueous 0.5% (v/v) H 2 O 2 solution, while stirring. The pH of the solution was adjusted to a value of 6.5 with a 5 N HCL solution. Adjustment of the pH was performed while stirring vigorously, in order to avoid formation of fiber precipitates. In this manner, a sterile collagen solution with a collagen concentration of 2.8% by weight was obtained.
[0048] All method steps were performed at room temperature, and all objects coming into contact with the collagen were rinsed with an 0.5% by weight H 2 O 2 solution before being used.
Example 2
Production of Porous Sponges Using Purified Sponge Collagen
[0049] A solution of sponge collagen with a collagen concentration of 2% by weight and a pH value of 6.5, which had been obtained using a method according to Example 1, was foamed by vigorous stirring with the aid of an Ultra Turrax. The collagen foam was cast into a rectangular mold made of polypropylene or polystyrene. The heights of the foam layers varied between 2 and 8 mm. The collagen foam was frozen in the mold at −40° C. and then lyophilized.
Example 3
Production of Sponges on the Basis of Precipitated Sponge Collagen
[0050] Porous sponges of sponge collagen were produced as described in Example 2. Subsequently, the freeze-dried sponges were subjected to a 30 minute acid treatment by immersion in an 0.1 N HCl solution. Following this treatment, the sponges were repeatedly washed with distilled water until the last residues of acid were removed.
[0051] These sponges were frozen in a still moist state and dried by lyophilization.
[0052] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | Methods are provided for purifying marine collagen and for processing the collagen into porous sponges. Products produced with these methods and the use of the products are also provided. | 2 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The invention relates to helical textiles.
[0003] 2. Description of the Related Art
[0004] One of the primary purposes of helical or spiral shaped material is to reinforce a composite material. Therefore, the fiber selection, fiber orientation and other features of the textile material must be considered to maximize the effectiveness of the textile material as a reinforcement to the final product.
[0005] Others have described woven helical fabrics, such as that disclosed in U.S. Pat. No. 5,222,866 that was issued to LaBrouche et al. on Jun. 29, 1993, and which is not admitted to being prior art by its mention in this Background section (the '866 patent). In the '866 patent the yarns in the warp (circumferential direction of the spiral) and yarns in the weft (radial direction of the spiral) are interlaced in the manner used with traditional weaving processes and typical weave designs, such as plain weave, satin weave, and basket weave.
[0006] One example is shown in FIG. 1 . The interlacings produced in the weaving process are necessary to hold the fabric together, and result in a lack of straightness in the yarns in either or both of the warp or weft directions called crimp. Crimp is introduced at fiber interlacings as illustrated in 106 a through 106 e between warp yarns 102 and weft yarns 104 . The crimp reduces the efficiency of the fibers to translate their properties to the ultimate composite structure or textile material.
[0007] Knitting processes can be divided into two categories: warp knitting and weft knitting. Weft knitting results in a textile structure where the yarns are interlocked to adjacent yarns resulting in very tortuous fiber paths. This does not allow for effective reinforcement for high performance composites.
[0008] What is needed, therefore, is a helical textile for reinforcing composite materials that does not crimp the fibers, but has uniform thickness, and process for making the same.
SUMMARY
[0009] The invention is a helical textile that does not have interlaced warp and weft fibers yet has uniform thickness for reinforcing composite materials. The invention is a warp knit helical textile having a repeating pattern of weft fibers of varying lengths such that the overall textile has a uniform thickness. The warp layers and weft layers are secured with non-reinforcing knitted stitches. The process of making the same includes a warp knitting machine modified to have conical take-up rolls and a means for inserting the repeating pattern of weft fibers of varying lengths. These and other features, advantages, and benefits of the present invention will become more apparent with reference to the appended drawings, description, and claims.
DRAWINGS
[0010] FIG. 1 is a side elevation of a textile of the prior art.
[0011] FIG. 2 is a side elevation of a textile according to the present invention.
[0012] FIG. 3 is an orthogonal view of a take-up roll and textile of the prior art.
[0013] FIG. 4 is an orthogonal view of a take-up roll and textile of the present invention.
[0014] FIG. 5 is a plan view of a helical textile having a uniform length of weft fibers.
[0015] FIG. 6 is a plan view of a helical textile according to the present invention having uniform thickness.
DESCRIPTION
[0016] The invention is a warp knit helical textile having a repeating pattern of weft fibers of varying lengths such that the overall textile has a substantially uniform thickness and more consistent warp to weft fiber distribution from ID to OD. Warp knitting uses manufacturing methods to orient the fibers in layers that are not interlaced. Rather, warp and weft fibers are constructed in discrete layers, one above the other.
[0017] The warp and weft fibers, in their respective layers, are straight, not crimped, and are parallel to adjacent fibers in the same layer. Turning to FIG. 2 , warp fibers 102 and those next to it are shown in cross section, and are interpreted as coming out of the page. The warp fibers 102 are in the circumferential direction, and are circumferentially parallel to each other. The weft fibers 104 are in the radial direction, and are radially parallel to each other. Unlike the prior art, no interlacing between warp fiber layer and weft fiber layers are needed. The warp fibers 102 and weft fibers 104 are secured to each other or bound together with a third fiber direction. This third direction is inserted with knitted stitches 108 . This third direction is not generally considered as a third reinforcing direction and is usually a non-reinforcing yarn type and in very low concentration compared to the warp and weft. The purpose of the knitted yarn is to hold the warp and weft layers together and to avoid the need to interlace the warp and weft. This third direction of yarn does not equate the resulting textile product to a three dimensional textile material since the resulting material described here is a single layer of knitted textile material. Contrast this to three dimensional weaving techniques that are used to manufacture multilayered textile materials.
[0018] The process of manufacturing the helical textile material utilizes modified warp knitting machinery. The modifications that are introduced are necessary to accommodate two issues: the take-up means to introduce the helical shape, and the weave design to accommodate the varying geometry of the textile structure from the inside diameter (“ID”) to the outside diameter (“OD”) of the helical material produced. In the present invention it is desired that the resulting material have an as constant as practical ratio of warp to weft fibers from ID to OD. This requires that the weft end count at the OD be higher than at the ID.
[0019] A warp knitting machine 120 of the prior art is shown in FIG. 3 . The knitting machine 120 has a cylindrical take-up roll 116 and produces a straight woven textile 114 . The warp knitting machine other than the take-up roll is shown as a black box in this drawing.
[0020] To make the helical textile 100 of the present invention, a warp knitting machine 122 is modified so that the cylindrical take-up rolls are replaced by conical take-up rolls 118 as shown in FIG. 4 . The warp knitting machine is also shown as a black box in this drawing. The angle of the conical roll or rolls is designed to produce the desired ID and OD ratio of the resulting helical textile material 100 . In this manner, the usual machine features necessary to adjust the take-up speed and such are maintained. A similar result is possible with a take-up mechanism that is a separate device from the knitting machine such that the material being knitted avoids the normal cylindrical take-up rolls. This separate device is controlled with mechanisms or electronic controls or both activated by features such as cams on the knitting machine.
[0021] The ratio of warp to weft fibers will depend on the particular final application of the composite structure. Most applications envisioned will require an as uniform as practical ratio of warp to weft from ID to OD regardless of what that ratio is. This requires that not all weft (radial) fibers continue from OD to ID. For example, if we assume that the full width weft fiber length for a particular design was intended to be three inches, in a straight weave, all weft fibers would be three inches long. If in the same example but with a helical textile as shown in FIG. 5 , and the weft fibers 104 are all three inches long, the spacing between adjacent weft fibers would be greater at the OD than at the ID. Therefore the weft fiber density near the ID would be greater than the OD and the thickness of the fabric near the ID would be greater than the OD. This would lead to non-uniform properties, which are undesirable.
[0022] This can be improved by introducing weft fibers 104 of less than three inch length, as shown in FIG. 6 . The intent is to make the final textile material as uniform as practical from OD to ID. The weft fibers will have one end at the OD of the textile, and the other end will proceed to some predetermined location part way from the OD to ID and then terminate or return towards the OD. If individual weft fibers were inserted, then they would terminate. If a continuous weft fiber were inserted, then it would bend and return towards the OD.
[0023] In a helical textile, the repeating sequence of weft fiber insertions might be three inches 104 a , one inch 104 b , two inches 104 c , one inch 104 b , and finally three inches again 104 a . This would allow more constant ratio of warp to weft from OD to ID. This also translates to a more constant thickness of the knitted material 100 across the width from ID to OD. It is understood that this is only an example of the different lengths of weft that can be used. A more uniform fabric can be made by increasing the number of different weft lengths, until it is no longer cost effective. The embodiment shown in FIG. 6 uses one weft insertion device.
[0024] More complex patterns having a single weft yarn of different lengths instead of pairs is shown in FIG. 7 . In this embodiment, three weft insertion devices are required.
[0025] The length of the weft insertion, also referred to as the shot or throw direction in knitting, can be controlled with cams, pins, knuckles, or electronically, depending on the style and age of the knitting machine used. The level of control generally available in all machines of this type is such that each weft insertion (shot or throw) can be tailored to be of different length. The combination, therefore, of variable length weft insertion and conical take-up will produce the material intended.
[0026] The helical fabric of the present invention has been said to have a “more constant” thickness than that of the prior art. The thickness of a single layer of fabric is not perfectly uniform or constant, but varies by the width of a weft fibers and insertion length. FIG. 8 is a graph that shows that the weft volume fraction 124 in the prior art increases from OD to ID. This increases the thickness. FIG. 9 shows that the weft volume fraction is more constant from the OD to the ID, and the thickness will be substantially more uniform.
[0027] FIG. 9 has a curve that represents weft fiber volume fraction from OD to ID 126 . The curve 126 has three peaks that correspond to the use of weft fibers of three different lengths. The difference between the peaks and troughs is the thickness “t”. The thickness “t” is not exactly the same as the thickness of a weft fiber, but it is related. The thickness “t” is also related to how closely the weft fibers are inserted together. The average thickness 128 is a flat line instead of a rising line like that in FIG. 8 . As defined in the specification and claims, therefore, the term “substantially” uniform shall be construed to mean uniform to within the thickness “t”.
[0028] Typical applications of a textile according to the present invention would use multiple layers, i.e. a coil, of helical textile. Another application might cut 360 degree pieces and then stack them to achieve multiple layers, alternating the position of the cut and splice. Other applications would use a continuous length of helical textile without cuts and splices.
[0029] The textile can be used to reinforce composite structures, or it could be used as a textile for non-composite applications, such as for a circular gasket. The fiber types that can be used include, without limitation, carbon, graphite, glass, and ceramic.
[0030] Although the present invention has been described with reference to particular embodiments, it will be apparent to those skilled in the art that variations and modifications can be substituted therefor without departing from the principles and spirit of the invention. | A helical textile having a substantially uniform thickness from ID to OD having circumferential warp fibers; non-interlaced radially aligned weft fibers having fiber lengths that may vary with the textile diameter to maintain constant textile thickness, the warp fibers and weft fibers not interlaced together; and non-reinforcing binding yarns securing the warp fibers to the weft fibers, thereby forming a helical textile. | 8 |
This application is a continuation of application Ser. No. 07/717918, filed Jun. 20, 1991, now abandoned.
FIELD OF THE INVENTION
This invention relates to a magnetic recording medium such as a magnetic tape, a magnetic sheet, or a magnetic disk.
BACKGROUND OF THE INVENTION
Generally, a magnetic recording medium such as a magnetic tape is prepared by coating a magnetic paint comprising a magnetic powder and a binder resin over a support.
In the recent tendency of making a recording density higher, electromagnetic conversion characteristics including, particularly, a chroma output have been required to be improved, because those characteristics have relatively been unsatisfactorily displayed. In the conventional magnetic recording media, Japanese Patent Publication Open to Public Inspection-hereinafter referred to as 'Japanese Patent O.P.I. Publication`- No. 61-8726/1986, for example, discloses the technique for making a dispersion state excellent and making a squareness ratio and a S/N ratio higher when a magnetic layer is comprised of a single layer and the adsorbate moisture of of a ferromagnetic alloy powder having a BET value of not less than 45 m 2 /g is made to be in a weight percentage of not higher than 1.2 wt. %. Japanese Patent O.P.I. Publication No. 60-187931/1985 proposes a medium containing a ferromagnetic material controlled to have a moisture in a weight percentage of not less than 0.8 wt % so as to be dispersed it uniformly when making use of a magnetic layer comprising a single layer and a ferromagnetic material having a BET value of 35 m 2 /g. Further, Japanese Patent O.P.I. Publication No. 64-19524/1989 and Japanese Patent Application Nos. 64-77450/1989 and 64-79307/1989 disclose each the techniques in which a plurality of magnetic layers are used and ferromagnetic metal powder is used in the uppermost layer, respectively.
According to the above-given techniques, however, an electromagnetic conversion properties including, particularly, a chroma output, have not been satisfactory and an adsorbate moisture has not also been satisfactorily controlled. Therefore, there have raised the problems that a residual solvent has still remained more in a magnetic layer and a running durability has also been deteriorated.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a magnetic recording medium comprising a plurality of magnetic layer, wherein a residual solvent remains few, a running durability is excellent, a mixedly kneading property is excellent, and the electromagnetic conversion properties including, particularly, a chroma output, are improved.
This invention relates to a magnetic recording medium comprising a non-magnetic support provided thereon with at least two magnetic layers out of which the uppermost layer contains a ferromagnetic metal powder having an adsorbate moisture within the range of 0.2 to 1.5 wt. % -in terms of the weight parts of the adsorbate moisture per 100 weight parts of the magnetic powder, and at least one of the other magnetic layers than the uppermost layer has a magnetic coercive force within the range of 500 to 1200 Oe.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings attached hereto each exemplarily illustrate the invention. FIGS. 1 and 2 illustrate, respectively, the cross-sectional views of the examples of magnetic recording media; and FIG. 3 shows a schematic illustration of an apparatus for preparing magnetic recording media.
DETAILED DESCRIPTION OF THE INVENTION
It is desirable that the magnetic recording media of the invention are to be comprised of a plurality of magnetic layers--namely, the uppermost layer and at least one lower layer--and that a plurality of the magnetic layers are to be adjacent to each other. It is also allowed that the above-mentioned lower layer may comprise either a single layer or not less than two layers.
Each of the layers can be formed so that the high-pass recording and regenerating properties such as an RF output and a lumi S/N may be made excellent in the upper layer out of the layers, and the relatively lower pass recording and regenerating properties such as a chroma output and a chroma S/N may be made excellent in the lower layer thereof.
For materializing the above-mentioned layer formation, it is generally desired to make greater the magnetic coercive force --Hc-- of each of the upper layers--including, particularly, that of the uppermost layer--than those of the lower layers and to make thinner the coated thickness--or, the layer thickness--of each of the upper layers. It is also desired to make the thicknesses of each of the layers to be not thicker than 1.5 μm. It is further desired the coated thickness of each of the lower layers adjacent to the above-mentioned upper layers is to be within the range of 1.5 to 4.0 μm.
There is the case where a definite interface is substantially present between each of the layers. However, there is also the case where an interface region is present, in which both of the layers are intermingled together with a certain thickness and, in this case, the upper or lower layers are served as each of the above-mentioned layers after removing the above-mentioned mingled interface. In particular, the media of the invention are particularly suitable for coating each of the magnetic layers in a wet-on-wet simultaneous multilayer coating process. It is the matter of course that a wet-on-dry process for coating the upper layer after drying the lower layer can also be used.
According to the magnetic recording media of the invention, it is particularly essential that the uppermost layer of a magnetic layer is to contain ferromagnetic metal powder having an adsorbate moisture in a weight percentage within the range of 0.2 to 1.5 wt. %. In other words, when an adsorbate moisture is not lower than 0.2 wt. %, each surface of the magnetic powder shows hydrophilicity to an inherently oleophilic solvent to deteriorate the affinity of both of the magnetic powder and the solvent so that the solvent adsorption is reduced by the magnetic powder. Therefore, the residual solvent is reduced. From the above-mentioned facts, the durability of the uppermost magnetic layer can be improved,--in other words, the magnetic powder can excellently be bonded by making use of binders--.
On the other hand, the adsorbate moisture of the above-mentioned ferromagnetic metal powder is restricted to be not higher than 1.5 wt. % so that the magnetic powder can keep the property to satisfactorily bond to the binder. Therefore, an excellent kneading property can be displayed and the magnetic powder can excellently be dispersed, so that an electromagnetic conversion property can also be improved. In addition to the above, any extra moisture is not adsorbed. Therefore, no reaction is produced with such a hardener as isocyanate, so that the pot-life of a coating solution can be excellent.
From the fact that the adsorbate moisture of the ferromagnetic metal powder contained in the uppermost layer is limited to be within the specific range of 0.2 to 1.5 wt. % as described above, the durability of the uppermost layer can be improved even when it is rubbed directly with a magnetic head or the like in severe conditions and, at the same time, the required performance--including the high-pass properties such as an RF output--can also be improved. As the results thereof, the above-mentioned uppermost layer can satisfactorily be used as the uppermost layer of a plurality of magnetic layers and, in addition, the electromagnetic conversion property can also be displayed excellently. The above-mentioned advantages are remarkably meaningful for improving the performance, when taking the advantages into consideration of the requirements for displaying the above-mentioned performance--such as the requirements that the coated thickness of the uppermost layer is to be thinned and the magnetic powder used therein is to be finely pulverized ferromagnetic metal powder--.
The adsorbate moisture contents of the above-described ferromagnetic metal powder are within the range of, desirably, 0.8 to 1.2 wt. % and, preferably, 0.9 to 1.1 wt. %.
The above-mentioned adsorbate moisture contents may be measured or selected in the following method. An adsorbate moisture is controlled by treating a ferromagnetic metal powder in an inert gas such as nitrogen gas containing a specific amount of moisture and the adsorbate moisture is measured by making use of a microconstituent moisture measurement instrument, Model CA-06 manufactured by Mitsubishi Chemical Industrial Co., Ltd., at a temperature of 120° C. in Karl Fischer's process.
In the invention, when the magnetic coercive force of at least one of the magnetic layers other than the uppermost layer is kept to be within the range of 500 to 1200 Oe, the electromagnetic conversion properties including, particularly, the chroma output, can be improved.
From the fact that the magnetic coercive force of at least one of the above-mentioned magnetic layers is kept within the range of not higher than 1200 Oe, a low-pass recording and a regenerating property can be improved and, in particular, the chroma output can also be improved. In addition to the above, from the fact that the above-mentioned magnetic coercive force is kept within the range of not lower than 500 Oe, a high-pass recording, a regenerating property and, particularly, an RF output and a lumi S/N ratio cannot be affected in the surface layer portions of the magnetic layers, so that the properties can be excellent.
The magnetic coercive force is desirably within the range of 700 to 1000 Oe and, preferably, within the range of 800 to 1000 Oe.
From the fact that the uppermost layer of the above-mentioned magnetic layers contains ferromagnetic metal powder, the filling property can be improved and a high frequency property can also be displayed. The magnetic coercive force of the above-mentioned ferromagnetic metal powder is desirably within the range of 1500 to 2000 Oe.
As shown in FIG. 1, for example, the magnetic recording media of the invention are each comprised of non-magnetic support 1 such as those made of polyethylene terephthalate laminated thereon with the first magnetic layer 2 and the second magnetic layer 4 in this order. And, on the opposite side of the support to the above-mentioned magnetic layer-laminated surface, there is coated with back-coat layer 3 which is, however, not necessarily provided. On the second magnetic layer, an over-coat layer may also be arranged. In the example shown in FIG. 2, the upper layer was separated into layer 5 and layer 6.
In the magnetic recording media shown in FIGS. 1 and 2, the coated thickness of the first magnetic layer 2 is to be kept within the range of, desirably, 1.5 to 4.0 μm--such as 2.5 μm--, and the coated thickness of the second magnetic layer 4 or a total coated thickness of magnetic layers 5 and 6 are desirable to be kept within the range of 0.1 to 1.5 μm--such
Into the second magnetic layer 4 or the third magnetic layer 6, ferromagnetic metal powder having an adsorbate moisture in a weight percentage within the range of 0.2 to 1.5 wt. % is to be contained.
The above-mentioned magnetic powder include, for example, the various kinds of ferromagnetic powder such as magnetic metal powder principally comprising Fe, Ni and Co, e.g., an Fe-Ni-Co alloy, an Fe-Ni alloy, an Fe-Al alloy, an Fe-Al-Ca alloy, an Fe-Al-Ni alloy, an Fe-Al-Co alloy, an Fe-Mn-Zn alloy, an Fe-Ni-Zn alloy, an Fe-Al-No-Co alloy, an Fe-Al-Ni-Cr alloy, an Fe-Al-Co-Cr alloy, an Fe-Co-Ni-Cr alloy, an Fe-Co-Ni-P alloy, and a Co-Ni alloy. For the magnetic layer 4 or 6 of the uppermost layer and the other magnetic layer 2 or 5--or, the other magnetic layers 5 and/or 2--, the former layer 4 or 6 is to be served as the uppermost layer and the latter magnetic layer 2 or 5, or 5 and 2 are to be served as the lower layer.
From among those magnetic powder, a ferromagnetic metal powder is selected suitably for the above-mentioned magnetic layers 4 and 6. For magnetic layers 2 and 5, a suitable metal oxide can be selected from the group consisting of γ-Fe 2 O 3 , Co-containing γ-Fe 2 O 3 , Fe 3 O 4 , and Co-containing Fe 3 O 4 .
Into each of the magnetic layers, it is allowed to add a monobasic aliphatic acid havine 12 to 20 carbon atoms -such as stearic acid-, an aliphatic acid ester having a total carbon atom number of 13 to 40, an abrasive--such as fused alumina--, a dispersant--such as powdered lecithin--, and an antielectrostatic agent--such as carbon black--.
As for the binders applicable to magnetic layer 2, 4, 5 or 6, those having an average molecular weight within the range of approximately 10000 to 200000 may be used. They include, for example, a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-vinylidene chloride copolymer, a vinyl chloride-acrylonitrile copolymer, a polyvinyl chloride, a urethane resin, a butadiene-acrylonitrile copolymer, a polyamide resin, polyvinyl butyral, a cellulose derivative--such as cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate and nitrocellulose--, a styrene-butadiene copolymer, a polyester resin, a variety of synthetic rubbers, a phenol resin, an epoxy resin, a urea resin, a melamine resin, a phenoxy resin, a silicone resin, an acryl type reactive resin, a mixture of a high molecular weight polyester resin and an isocyanate prepolymer, a mixture of polyester polyol and polyisocyanate, a urea formaldehyde resin, a mixture of a low molecular weight glycol / a high molecular weight diol/isocyanate, and the mixtures thereof.
The above-mentioned binders are desirably comprised of the resins each containing hydrophilic polar groups such as--SO 3 M, --COOM and PO(OM') 2 --in which M represents hydrogen or an alkali metal such as lithium, potassium and sodium; and M' represents hydrogen, an alkali metal such as lithium, potassium and sodium, or a hydrocarbon residual group--. Such a resin as mentioned above is improved in the affinity to magnetic powder by the presence of the intramolecular polar groups. Therefore, the dispersibility of the magnetic powder can further be improved and the magnetic powder can be prevented from cohesion, so that the stability of a coating solution can further be improved. The above-mentioned advantages also bring a medium in the improvement of the durability.
The above-mentioned binders including particularly the vinyl chloride type copolymers can be prepared by copolymerizing a vinyl chloride monomer, a copolymerizable monomer containing the alkali salt of sulfonic acid, carboxylic acid or phosphoric acid and, if required, the other copolymerizable monomers than the above-given monomers. Because these copolymers are prepared in a vinyl-synthesizing process, they can readily be prepared and the copolymeric components can variously be selected out, so that they can be controlled so as to have the optimum characteristics.
It is desirable that the metals of the salts such as those of sulfonic acid, carboxylic acid or phosphoric acid are to be the alkali metals -including particularly those of sodium, potassium or lithium-. Among them, those of potassium are preferable from the viewpoints of solubility, reactivity and yield.
In the meanwhile, when providing back-coat layer 3, it is prepared by containing non-magnetic particles such as those of barium sulfate into the above-mentioned binder, and the resulting coating solution is coated over the rear surface of a support.
The raw materials of the above-mentioned support 1 include, for example, plastics such as polyethylene terephthalate and polypropylene, metals such as Al and Zn, glass, BN, Si-carbide, and seramics such as porcelain and earthenware.
An example of the apparatuses for preparing the above-described media is shown in FIG. 3.
When preparing the medium shown in FIG. 1 by making use of the above-mentioned medium preparing apparatus, the following steps are taken. First, film-shaped support 1 let out from supply roller 32 is coated thereon with each of the coating paints for the above-mentioned magnetic layers 2, 4 by extrusion coater 10. Then, the resulting coated support is magnetically aligned by a front aligning magnet 33 having 2000 Gauss for example and is then introduced into drier 34 attached with a rear aligning magnet 35 havinf 2000 Gauss for example. Further, it is dried by blowing hot air from the nozzles arranged respectively to the upper and lower parts of the drier 34. Next, support 1 already coated with each of the magnetic layers and dried is introduced into a supercalender 37 comprising a combination of calender rollers 38 and is then subjected to a calender treatment. The calendered support 1 is then taken up by and round take-up roller 39. Each of the paints may also be supplied to extrusion coaters 10 and 11 through an in-line mixer not shown in the drawing. In the drawing, arrow mark D indicates the direction of transporting a non-magnetic film base. Extrusion coaters 10 and 11 are provided with solution reservoirs 13 and 14, respectively, and the paints extruded out of each of the coaters are multicoated over the calendered support 1 in a wet-on-wet process.
For preparing the medium shown in FIG. 2, it is allowed to provide another additional coater to the preparation apparatus shown in FIG. 3.
EXAMPLES
The following examples of the invention will now be detailed.
It is allowed to change variously the following components, proportions or the ratios, operational orders, and the like, without departing from the spirit of the invention. The term, `part` or `parts` expressed herein, means `a part or parts by weight`.
EXAMPLE 1
First, magnetic paint A for the upper layer use and magnetic paint B for the lower layer use were prepared by mixedly kneading each of the following compositions by making use of a kneader and then by dispersing them by making use of a sand mill.
______________________________________<Magnetic paint A for the upper layer use>______________________________________Ferromagnetic metal powder, 100 partsComposition: Fe:Al = 100:5, Hc: 1580 Oe,σ.sub.s : 120 emu/g, BET specific surface area:56 m.sup.2 /g, and adsorbate moisture content:1.0 wt %-Vinyl chloride type resin containing 10 partspotassium sulfonate,Trade name, MR110, manufactured byNippon Zeon Co.-Cyclohexanone 100 partsToluene 100 parts______________________________________
5 parts each of polyisocyanate (colonate L, manufactured by Nihon Polyurethane Industry Co., Ltd.) were added to the magnetic paint A and B. The magnetic paint B for the lower layer use and the magnetic paint A for the upper layer use were coated in this order over to a 10.0 μm-thick polyethylene terephthalate film base, so as to have the coated thicknesses of 0.5 μm for the upper layer and 2.5 μm for the lower layer, respectively, in a wet-on-wet coating process by making use of the apparatus shown in FIG. 3. Then, after aligning and drying the coated support, a calender treatment was applied.
After that, the paint for BC layer use having the following compositions was coated over to the opposite side of the magnetic layers so as to have a dried thickness of 0.8 μm.
______________________________________Carbon black, -Raven 1035- 40 partsBarium sulfate, 10 partshaving an average particle size of 300 mμ-Nitrocellulose 25 partsN-2301, 25 partsmanufactured by Nippon Urethane Co.-Polyisocyanate compound (Coronate L, 10 partsproduced by Nippon Polyurethane Industry)Cyclohexanone 400 partsMethyl ethyl ketone 250 partsToluene 250 parts______________________________________
In the above-mentioned procedures, a wide magnetic film was obtained and was then taken up. The resulting film was cut into every 8 mm wide, so that the 8 mm wide tapes could be prepared.
EXAMPLES 2 and 3
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the Co-containing iron oxide--having an Hc: 810 Oe--used for the lower layer of Example 1 was replaced by the Co-containing iron oxide shown in the following Table-1A.
EXAMPLE 4
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by Fe-Ni magnetic powder--having an adsorbate moisture content of 1.0 wt. %--.
EXAMPLES 5 and 6
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by Fe-Ni magnetic powder--having an adsorbate moisture content of 1.0 wt. %--and the Co-containing iron oxide for the lower layer of Example 1 was replaced by the Co containing iron oxide shown in the following Table-1A.
EXAMPLES 7, 8 and 9
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by the magnetic powder shown in the following Table-1A.
EXAMPLES 10 through 15
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder used for the upper layer of Example 1 was replaced by the magnetic powder shown in the following Table-1A and the Co-containing iron oxide--having an Hc: 810 Oe--for the lower layer of Example 1 was replaced by the Co-containing iron oxide shown in the following Table-1A.
COMPARATIVE EXAMPLES 1, 2 and 3
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by the magnetic powder shown in the following Table-1B.
COMPARATIVE EXAMPLES 4, 5 and 6
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the Co-containing iron oxide--having an Hc: 810 Oe--used for the lower layer of Example 1 was replaced by the Co containing iron oxide shown in the following Table-1B.
COMPARATIVE EXAMPLES 7 and 8
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by the magnetic powder shown in the following Table-1B and the Co-containing iron oxide--having an Hc: 810 Oe--used for the lower layer of Example 1 was replaced by the Co-containing iron oxide shown in the following Table-1B.
COMPARATIVE EXAMPLES 9 and 10
The 8 mm-wide tapes were prepared in the same manner as in Example 1, except that the magnetic powder for the upper layer of Example 1 was replaced by Co-containing iron oxides--out of them, one having an adsorbate moisture content of 1.0 wt. % and the other having an adsorbate moisture content of 0.1 wt. %--.
<The method of measuring characteristics in the examples and the comparative examples>
The following performance evaluation of the resulting tapes were tried, and the results thereof are shown in the following Table-1.
RF output and lumi S/N:
A deck, Model V-900 manufactured by Sony Corp. was used. A 100% white signal was input and regenerated on a subject magnetic recording medium, on a standard level. A regenerated video signal was input to a noise meter, Model 921D/1 manufactured by Shiba-Soku Lab., and a lumi S/N was read from the resulting absolute noise value.
Chroma S/N and chroma output:
A deck, Model V-900 manufactured by Sony Corp., was used, and a regeneration was carried out. Further, a noise meter, manufactured by Shiba-Soku Lab., was used, In comparing the resulting tapes to a control tape, the difference in the S/N ratios of the samples between the chroma signals were obtained.
Adsorbate moisture content:
A microconstituent moisture measuring instrument, Model CA-06 manufactured by Mitsubishi Chemical Industrial Co., was used to measure the respective adsorbate moisture contents at a temperature of 120° C. in a Karl Fischer's process.
Running durability:
At a temperature and humidity of 40° C. and 80% RH, the whole length of every tape was ran through 50 passes. After completing the running them, the resulting tape damages were visually judged.
The results of the dudgements were graded as follows:
◯: No edge damage was produced;
Δ: Edge damages were produced in a part of the subject tape; and
X: Edge damages were produced all along the length of the subject tape.
Residual solvent content:
A gaschromatographic instrument, Model HP-5890 manufactured by Yokogawa-Hewlet Packard Inc., was used to measure the resulting residual solvent contents.
First, the residual solvent contents of the whole magnetic layer were measured, and the magnetic layer portion of the uppermost layer was removed by grinding by making use of a diamond wheel. Next, the residual solvent contents of the remaining magnetic layer portions were then measured. Then, the residual solvent content of the uppermost layer was calculated out by deducting the residual solvent contents of the remaining magnetic layer portions from the whole residual solvent contents. The resulting residual solvent content of the uppermost layer are expressed in terms of a coated thickness of 3.0 μ.
TABLE-1A__________________________________________________________________________Example No. 1 2 3 4 5 6 7 8 9 10__________________________________________________________________________The uppermostmagnetic layerComponent Fe--Al Fe--Al Fe--Al Fe--Ni Fe--Ni Fe--Ni Fe--Al Fe--Al Fe--Al Fe--AlAdsorbate 1.0 1.0 1.0 1.0 1.0 1.0 0.5 0.2 1.5 0.8moisturecontent (wt %)The lower layermagnetic powder Co- " " " " " " Co- " "component containing containing iron oxide iron oxideThe lower layer 905 650 1150 905 650 1150 904 901 906 907coercive force (Oe)Magnetic powder 810 600 1070 810 600 1070 810 810 810 810coercive force ofthe lower layer (Oe)RF output (dB) 1.7 1.6 1.8 1.9 1.8 1.9 1.8 1.9 1.5 1.7Lumi S/N (dB) 1.1 1.0 1.2 1.3 1.2 1.4 1.1 1.2 0.9 1.0Chroma output (dB) 3.0 3.6 2.5 3.1 1.2 1.4 1.1 3.2 2.8 2.9Chroma S/N (dB) 0.7 0.5 0.6 0.8 0.7 0.9 0.8 0.8 0.6 0.7Running propert ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘Residual solvent 2.1 1.9 2.2 2.2 2.1 2.2 2.1 2.9 2.0 2.1content of the upper-most layer (μl/m.sup.2)__________________________________________________________________________ Example No. 11 12 13 14 15__________________________________________________________________________ The uppermost magnetic layer Component Fe--Al Fe--Al Fe--Al Fe--Al Fe--Al Adsorbate 1.2 1.0 1.0 1.0 1.0 moisture content (wt %) The lower layer magnetic powder " " " " " component The lower layer 906 500 702 1007 1200 coercive force (Oe) Magnetic powder 810 450 630 915 1140 coercive force of the lower layer (Oe) RF output (dB) 1.6 1.3 1.5 1.8 1.9 Lumi S/N (dB) 1.1 0.9 1.0 1.2 1.5 Chroma output (dB) 3.0 3.4 3.2 2.8 2.1 Chroma S/N (dB) 0.7 0.6 0.7 0.8 0.7 Running propert ∘ ∘ ∘ ∘ ∘ Residual solvent 2.0 2.1 2.1 2.1 2.1 content of the upper- most layer (μl/m.sup.2)__________________________________________________________________________
TABLE-1B__________________________________________________________________________Comparativeexample No. 1 2 3 4 5 6 7 8 9 10__________________________________________________________________________The uppermostmagnetic layerComponent Fe--Al Fe--Al Fe--Al Fe--Al Fe--Al Fe--Al Fe--Al Fe--Al Co- Co- containing containing iron iron oxideAdsorbate 0.1 0 1.6 1.0 1.0 1.0 0.1 1.6 1.0 0.1moisturecontent (wt %)The lower layermagnetic powder Co- " " " " Fe--Al Co- " Co- "component containing containing containing iron oxide iron oxide iron oxideThe lower layer 901 895 903 450 1310 1550 450 1301 902 904coercive force (Oe)Magnetic powder 810 810 810 403 1250 1540 403 1240 810 810coercive force ofthe lower layer (Oe)RF output (dB) 1.9 1.9 1.1 1.1 1.8 1.8 1.1 1.2 -1.5 -1.8Lumi S/N (dB) 1.2 0.9 1.0 1.1 0.9 1.0 1.2 1.5 -2.0 -2.1Chroma output (dB) 3.2 3.1 2.4 3.6 1.6 0.2 3.5 1.3 2.9 2.8Chroma S/N (dB) 0.9 0.8 0.4 0.5 0.8 0.9 0.4 0.3 0.1 -0.1Running property Δ X ∘ ∘ ∘ ∘ Δ ∘ ∘ ∘Residual solvent 4.2 6.1 2.0 2.0 2.1 2.0 4.3 2.0 2.1 2.6content of the upper-most layer (μl/m.sup.2)__________________________________________________________________________
From the results thereof, it can be found in accordance with the invention that, when the magnetic layer of the uppermost layer contains ferromagnetic metal powder having an adsorbate moisture content in a weight percentage within the range of 0.2 to 1.5 wt. %, the kneading property can be excellent, the residual solvent content can remarkably be reduced, the running durability can greatly be improved, and the RF output and lumi S/N can each be excellent. In addition to the above, it can be found that, when the magnetic coercive force of the lower layer is kept to be within the range of 500 to 1200 Oe, the electromagnetic conversion characteristics including, particularly, the chroma output, can be improved, and the RF output, lumi S/N and chroma S/N can also be excellent. Besides the above, when making use of iron oxide magnetic powder in the uppermost layer, it is obvious that the characteristics cannot be affected so much by the adsorbate moisture contents--See Comparative Examples 9 and 10--; and, when magnetic metal powder is used in the uppermost layer, the superiority of the invention-- i.e., the superiority to others in the influences of the adsorbate moisture contents--can be remarkable to others.
Next, the performance evaluations were tried in the same manner as in the aforementioned evaluations when a magnetic layer is comprised of three layers, namely, layers 2, 5 and 6 as shown in FIG. 2, -provided, however, that the upper layer 6 and the lower layer 2 have each the same compositions as afore-given and the intermediate layer 5 has the same compositions as in lower layer 2, except that the Hc of intermediate layer 5 is of the middle between those of the upper and lower layers, and that the coated thicknesses of the upper layer, the intermediate layer and the lower layer are 0.3 μm, 0.3 μm, and 2.5 μm, respectively--. The results thereof were obtained as shown in the following Table-2. According to the results thereof, it can be proved that the performance can fully be displayed as same as in the case of the foregoing two-layer structure, when the invention is constituted.
______________________________________Inventiveexample No. 16 17______________________________________Magnetic powder ofthe uppermost layerComponent Fe--Al Fe--AlAdsorbate 0.2 1.5moisturecontent (wt %)Magnetic powder ofthe interlayercomponent Co-containing " iron oxideThe lower layer 905 906coercive force (Oe)Magnetic powder ofthe lower layercomponent Co-containing " iron oxideThe lower layer 810 812coercive force (Oe)RF output (dB) 1.7 1.6Lumi S/N (dB) 1.2 1.1Chroma output (dB) 3.0 2.8Chroma S/N (dB) 0.7 0.6Running property ∘ ∘Residual solvent 2.9 2.0content of the upper-most layer (μl/m.sup.2)______________________________________
In the invention, as described above, the magnetic layer arranged onto a non-magnetic support is comprised of at least two layers, and the uppermost layer of the above-mentioned magnetic layers contains ferromagnetic metal powder having an adsorbate moisture content in a weight percentage within the range of 0.2 to 1.5 wt. %. Therefore, the running durability can be improved by the reduction of a residual solvent content and, further, the electromagnetic conversion characteristics can also be improved by obtaining an excellent kneading property. Also, at least one magnetic layer other than the uppermost layer has a magnetic coercive force within the range of 500 to 1200 Oe. Therefore, the electromagnetic conversion characteristics including, particularly, a chroma output can be improved. Further, the above-mentioned magnetic layer is comprised of at least two layers. Therefore, a substantially wide frequency region can be covered and, in particular, the RF output and lumi S/N can also be made excellent by containing ferromagnetic metal powder into the uppermost layer of the magnetic layers. | A magnetic recording tape with plural magnetic layers, having both the electromagnetic conversion properties, particularly the chromatic output, and the corrosion resistance is disclosed.
The top layer contains a magnetic metal powder having 0.2-1.5% of water when it is mixed into a magnetic paint and a layer other than the top layer has the coercive force of 500 to 12000 Oe. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2015/079113 filed Dec. 9, 2015, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 102015201143.7 filed Jan. 23, 2015. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a procedure for preheating untreated water, in particular in a power plant. The invention further relates to a power plant having a water/steam circuit.
BACKGROUND OF INVENTION
[0003] In the case of power plants that have steam extraction without, or with partial, return of the condensate, frequently there is a requirement for large quantities of deionate, i.e. demineralized (also: deionized) water, in order to compensate the circuit losses resulting from the steam extraction. At low outside temperatures, in particular, the untreated water does not have the temperature necessary for production of deionized water. Hitherto in this case, the untreated water was preheated by means of steam or electrically, resulting in a high requirement in respect of machinery or electrical equipment resources, in reduction of the efficiency or in an increased house load.
SUMMARY OF INVENTION
[0004] An object is to further develop the said procedure and the said apparatus such that a considerable reduction of the resource requirement is achieved.
[0005] These objects are achieved according to the invention by the procedure for preheating untreated water as claimed, and the power plant as claimed. Advantageous developments of the invention are defined in the respective dependent claims. In that, in the case of a procedure for preheating untreated water in a power plant having a water/steam circuit, the power plant comprising a steam generator, a steam turbine and steam lines, of which at least some connect the steam generator to the steam turbine, untreated water for production of deionized water is heated by waste water from the water/steam circuit, wherein the waste water is admixed with the untreated water for the purpose of heating the untreated water, it is achieved that residual heat in the waste water is utilized and the house load of the power plant is reduced, or the efficiency is increased.
[0006] Waste water in this case is the water that leaves the water/steam circuit and that is usually discharged into the cooling water or discarded following appropriate recooling. Vessels for waste water, and associated pumps, and the pipeline to the cooling water are already present. It is necessary to add only a line branch to an untreated-water mixer having fittings.
[0007] If the waste water is admixed with the untreated water for the purpose of heating the untreated water, no heat losses occur, as in the case of heating by means of low-pressure steam. Also, with appropriate selection of the waste water, the latter can be used again as untreated water.
[0008] It is expedient in this case if the waste water is a blowdown water from the steam generator, in particular from steam drums.
[0009] Alternatively or additionally, it may be advantageous if the waste water is a condensate from the steam lines that are automatically drained at low points.
[0010] In respect of good intermixing of waste water and untreated water, it is advantageous if the waste water is distributed in the untreated water.
[0011] Further, it is advantageous if an untreated water temperature is controlled, by closed-loop control, by alteration of a blowdown water quantity.
[0012] In particular, it may be advantageous if, on the basis of a heat demand for the preheating, more water is blown down than is required on the basis of a water chemistry requirement. Only in this case, however, there is also only a comparatively small reduction in efficiency, since in this case additional heat is extracted from the steam generator. The electrical house load is not increased. In any case, closed-loop control of the untreated water temperature can be effected by variation of the boiler blowdown. It is thus also possible to set an optimal temperature for the production of deionized water.
[0013] In the case of the power plant according to the invention having a water/steam circuit, the power plant comprising a steam generator, a steam turbine and steam lines, which at least in part connect the steam generator to the steam turbine, an untreated-water mixer and a vessel for waste water from the water/steam circuit, the untreated-water mixer and the vessel for waste water from the water/steam circuit are fluidically connected to each other, wherein an apparatus for distributing the waste water in the untreated water is provided in the untreated-water mixer. A distribution of the waste water in the untreated water improves the intermixing.
[0014] It is expedient in this case if the vessel for waste water from the water/steam circuit is connected to the steam generator. In particular, blowdown water is produced regularly at the steam drums of the steam generator.
[0015] Further, it is expedient if the vessel for waste water from the water/steam circuit is connected to steam lines. The latter are drained automatically at their low points, and the condensate produced is usually not contaminated.
[0016] In a further advantageous embodiment of the power plant according to the invention, a closed-loop controller for closed-loop control of the untreated water temperature is provided. The optimal temperature for the production of deionized water can thus be set.
[0017] It is expedient in this case if the closed-loop control for the untreated water temperature comprises an open-loop control of a blowdown water quantity.
[0018] Unlike condensate from the steam lines, the blowdown water quantity is easily set.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention is explained exemplarily in greater detail on the basis of the drawings. There are shown schematically, and not true to scale:
[0020] FIG. 1 a power plant, and
[0021] FIG. 2 the procedure for preheating untreated water according to the invention.
DETAILED DESCRIPTION OF INVENTION
[0022] FIG. 1 shows a power plant 1 according to the invention. The power plant 1 according to FIG. 1 is designed as a gas and steam turbine plant, and comprises a gas turbine installation 11 and a steam turbine installation 12 . The gas turbine installation 11 comprises a gas turbine 13 that has a coupled air compressor 14 , and, upstream from the gas turbine 13 , a combustion chamber 15 , which is connected to a compressed-air line 16 of the compressor 14 . The gas turbine 13 and the air compressor 14 , and a generator 17 , are arranged on a common shaft 18 . The fuel supply is effected via a fuel line 40 .
[0023] The steam turbine installation 12 comprises a steam turbine 4 having a coupled generator 19 , and, in a water/steam circuit 2 , a condenser 20 downstream from the steam turbine 4 , and a waste-heat steam generator 3 . In FIG. 1 the steam turbine 4 is represented in a highly simplified form, and in the case of large plants is usually composed of a plurality of pressure stages, not shown in FIG. 1 , which typically drive the generator 19 via a common shaft 21 .
[0024] The waste-heat steam generator 3 is also represented in a highly simplified form. For the purpose of supplying working fluid, expanded in the gas turbine 13 , into the waste-heat steam generator 3 , there is a waste-gas line 22 connected to an input 23 of the waste-heat steam generator 3 . The expanded working fluid from the gas turbine 13 leaves the waste-heat steam generator 3 , via the output 24 thereof, in the direction of a flue, not represented in greater detail.
[0025] A feed-water vessel/deaerator 25 can be fed with condensate from the condenser 20 , via a condensate line 26 , connected into which there is a condensate pump unit 27 . The arrangement of the feed-water vessel/deaerator 25 in the water/steam circuit 2 of FIG. 1 is represented merely as an example. A feed-water pump 28 brings the feed water, flowing out from the feed-water vessel/deaerator 25 , to an appropriate pressure level. The feed water is supplied to a corresponding pressure stage in the waste-heat steam generator 3 via a feed-water preheater 29 , which is connected on the output side to a steam drum 30 . The steam drum 30 is connected to an evaporator 31 , arranged in the waste-heat steam generator 3 , for the purpose of forming a water/steam circuit. For the purpose of removing live steam, the steam drum 30 is connected to a superheater 32 that is arranged in the waste-heat steam generator 3 and that on the output side is connected, via steam lines 5 , to a steam inlet 33 of the steam turbine 4 .
[0026] Shown exemplarily on the steam turbine 4 is a steam extraction 34 for a steam supply system. In principle, steam extractions may be provided at various points on the steam turbine, but also in the region of the waste-heat steam generator 3 . Exemplarily, a condensate return 35 goes into the condensate line 26 .
[0027] The power plant 1 additionally comprises an untreated-water mixer 6 , and a vessel 7 for waste water from the water/steam circuit 2 , which, according to the invention, are fluidically connected to each other. An apparatus 8 for distributing the waste water in the untreated water is provided in the untreated-water mixer 6 .
[0028] The vessel 7 for waste water from the water/steam circuit 2 is connected both to the steam generator 3 and there, in particular, to the steam drum 30 , and to the steam lines 5 .
[0029] Provided for the purpose of closed-loop control of the untreated water temperature there is a closed-loop controller 9 that, on the one hand, senses a current untreated water temperature by means of a temperature sensor 36 , and on the other hand, by means of the pump 37 connected into the water line 41 between the vessel 7 and the untreated-water mixer 6 , conveys an appropriate quantity of waste water from the vessel 7 into the untreated-water mixer 6 . If the heat demand for the preheating of the untreated water in the untreated-water mixer 6 exceeds that which can be achieved by the quantity of water present in the vessel 7 , the blown-off water quantity is increased, by means of a corresponding open-loop control 10 , even if this were not necessary on the basis of a water chemistry requirement.
[0030] Finally, FIG. 1 shows an apparatus 38 for water conditioning, including demineralization, that is arranged between the untreated-water mixer 6 and the feed-water vessel/deaerator 25 , with corresponding pumps 39 . Here, also, the infeed of deionized water into the water/steam circuit 2 is represented merely exemplarily.
[0031] FIG. 2 shows the procedure for preheating untreated water in a power plant 1 , in which untreated water for production of deionized water is heated by waste water from the water/steam circuit 2 . In a first step 42 it is checked whether the temperature of the untreated water need be raised at all. If this is not the case, the procedure is terminated 43 . If the temperature of the untreated water is to be raised, it is checked in a second step 44 whether the quantity of waste water present would be sufficient for this purpose. If it is, in a third step 45 waste water is routed, out of the vessel 7 for waste water from the water/steam circuit 2 , into the untreated-water mixer 6 . If the quantity is insufficient, in addition to the third step 45 a fourth step 46 is performed, in which a further blowdown is effected, as a result of which the water inflow to the vessel 7 is increased. | A method for preheating untreated water in a power plant having a water/steam circuit, the power plant has a steam producer, a steam turbine, and steam lines, of which at least some connect the steam producer to the steam turbine, wherein untreated water for producing deionized water is heated by means of wastewater from the water/steam circuit and the wastewater is added to the untreated water in order to heat the untreated water. A power plant is adapted for preheating untreated water by the method. | 5 |
FIELD OF THE INVENTION
[0001] A process to conduct an improved SAGD process for bitumen recovery, by injecting oxygen and steam separately, into a bitumen reservoir, and to remove, as necessary, non-condensable gases produced by combustion, to control the reservoir pressures. In one aspect of the invention a cogeneration operation is locally provided to supply oxygen and steam requirements.
[0002] Acronyms Used Herein:
SAGD—Steam Assisted Gravity Drainage SAGDOX—SAGD+Oxygen SAGDOX (9)—SAGDOX with 9% (v/v) oxygen in steam+oxygen ISC—In Situ Combustion EOR—Enhanced Oil Recovery LTO—Low Temperature Oxidation (150-300° C.) HTO—High Temperature Oxidation (380-800° C.) ETOR—Energy to Oil Ratio (MMBTU/bbl) ETOR (steam) ETOR of steam component VT—Vertical (well) HZ—Horizontal (well) OBIP—Original Bitumen in Place STARS—Steam Thermal and Advanced Reservoir Simulator (CMG, Calgary) SOR—Steam to Oil Ratio (bbls/bbl) PG—Produced (non-condensable) Gas ASU—Air Separation Unit (to produce oxygen gas) JCPT—Journal of Canadian Petroleum Technology OGJ—Oil & Gas Journal JPT—Journal of Petroleum Technology SPE—Society of Petroleum Engineers COFCAW—Combination of Forward Combustion and Waterflood CAGD—Combustion Assisted Gravity Drainage CHOA—Canadian Heavy Oil Association DOE—(US) Department of Energy GOR—Gas to Oil Ratio
BACKGROUND OF THE INVENTION
References Used
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Belgrave, J. D. M. et al—“SAGD Optimization with Air Injection” SPE 106901, 2007
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Butler, R. M.—“Thermal Recover of Oil & Bitumen”, Prentice-Hall, 1991
Cenovus—OGT, Sep. 6, 2010
Chinna, H. et al—“Hydrocarbon Recovery Facilitated by in Situ Combustion using Horizontal Well”, Int'l Pat. WO 2006/074555 A1, 2006.
Chu, C.—“A Study of Fireflood Field Projects”, JPT, February 1977
Craig, F. F. et al—“A Multipilot Evaluation of the COFCAW Process”, JPT, June 1974
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Doschner, T. M.—“Factors that Spell Success in Steaming Viscous Crudes”. OGJ, Jul. 11, 1996
Gates, I. et al—“A Process for In Situ Recovery of Bitumen and Heavy Oil” US Pat. 2005/0211434 A1, September 2005
Gates, I. et al—“In Situ Heavy Oil and Bitumen Recovery Process” US Pat. 2010/0065268 A1, March 2010.
Gates, C. F. et al—“In Situ Combustion in the Tulane Formation, South Belridge Field, Kerm County California”, SPE 6554, April 1977
Graves, M. et al, “In Situ Combustion (ISC) Process Using Horizontal Wells” JCPT, April, 1996
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Pfefferle, W. C. “Method for in Situ Combustion of in-Place Oils”, U.S. Pat. No. 7,581,587 B2, Sep. 1, 2009
Pfefferle, W. C.—“Method for CAGD Recovery of Heavy Oil”, Int'l Pat. WO 2008/060311 A2, May 2008
Pfefferle, W. C. “Method for CAGD Recovery of Heavy Oil” US Pat. 2007/0187094 A1, Aug. 16, 2007
Prats, M. et al—“In Situ Combustion Away from Thin, Horizontal Gas Channels”, SPE 1898, October 1967
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Sullivan, J. et al—“Low Pressure Recovery Process for Acceleration of In Situ Bitumen Recovery”, US Pat. 2010/0096126 A1, April 2010.
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Wylie, I. et al—“Hot Fluid Recovery of Heavy Oil with Steam and Carbon Dioxide”, US Pat. 2010/0276148 A1, November 2010.
Yang X et al—“Design of Hybrid Steam—ISC Bitumen Recovery Processes” Nat. Resources Res., Sep. 3, 2009(1)
Yang, X. et al—“Design and Optimization of Hybrid Ex Situ/In Situ Steam Generation Recovery Processes for Heavy Oil and Bitumen”. SPE Symposium, Calgary, Alta., Can., October, 2008.
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[0067] Today (2011), the leading in situ EOR process to recover bitumen from oil sands reservoirs, such as found in the Athabasca region of Alberta in Canada, is SAGD (steam assisted gravity drainage). Bitumen is a very heavy type of oil that is essentially immobile at reservoir conditions, so it is difficult to recover. In situ combustion (ISC) is an alternative process that, so far, has shown little application for bitumen recovery.
[0068] SAGDOX (SAGD with oxygen) is another alternative process, for bitumen EOR that can be considered as a hybrid process combining the attributes of SAGD (steam) and ISC (oxygen). SAGDOX uses a modified SAGD geometry with extra wells or segregated injector systems to allow for separate continuous injection of oxygen and steam and removal on non-condensable gases produced by combustion.
1. Prior Art Review
Bitumen EOR
2.1 SAGD
[0069] In the early days of steam EOR, the focus was on heavy oil (not bitumen) and two process types, using vertical well geometry—steam floods (SF), where a steam injector would heat and drive oil to a producer well (California heavy oil EOR used this process) and cyclic steam simulation (CCS) where, using a single vertical well, steam was injected, often at pressures that fractured the reservoir. This was followed by a soak period to allow oil time to be heated by conduction and then a production cycle (Cold Lake, Alberta oil is recovered using this process).
[0070] But, compared to these processes and heavy oil, bitumen causes some difficulties. At reservoir conditions, bitumen viscosity is large (>100,000 cp.), bitumen will not flow and gas/steam injectivity is very poor or near zero. Vertical well geometry will not easily work for bitumen EOR. We need a new geometry with short paths for bitumen recovery and a method to start-up the process so we can inject steam to heat bitumen.
[0071] In the 1970-1980's using new technology to directionally drill wells and position the wells accurately, it became possible to drill horizontal wells for short-path geometry. Also, in the early 1970's, Dr. Roger Butler invented the SAGD process, using horizontal wells to recover bitumen (Butler (1991)). FIG. 1 shows the basic SAGD geometry using twin parallel horizontal wells with a separation of about 5 m, with the lower horizontal well near the reservoir bottom (about 2 to 8 m. above the floor), and with a pattern length of about 500 to 1000 m. The SAGD process is started by circulating steam until the horizontal well pair can communicate and form a steam (gas) chamber containing both wells. FIG. 17 shows how the process works. Steam is injected through the upper horizontal well and rises into the steam chamber. The steam condenses at/near the cool chamber walls (the bitumen interface) and releases latent heat to the bitumen and the matrix rock. Hot bitumen and condensed steam drain by gravity to the lower horizontal production well and are pumped (or conveyed) to the surface. FIG. 18 shows how SAGD matures—A young steam chamber has oil drainage from steep sides and from the chamber top. When the chamber grows and hits the ceiling (top of the net pay zone), drainage from the chamber top ceases and the sides become flatter, so bitumen drainage slows down.
[0072] Steam injection (i.e. energy injection) is controlled by pressure targets, but there also may be a hydraulic limit. The steam/water interface is controlled to be between the steam injector and the horizontal production well. But when fluids move along the production well there is a natural pressure drop that will tilt the water/steam interface ( FIG. 13 ). If the interface floods the steam injector, we reduce the effective length. If the interface hits the producer, we short circuit the process and produce some live steam, reducing process efficiency. With typical tubulars/pipes, this can limit well lengths to about 1000 m.
[0073] SAGD has another interesting feature. Because it is a saturated-steam process and only latent heat contributes directly to bitumen heating, if pressure is raised (higher than native reservoir pressure) the temperature of saturated-steam is also increased, Bitumen can be heated to a higher temperature, viscosity reduced and productivity increased. But, at higher pressures, the latent heat content of steam is reduced, so energy efficiency is reduced (SOR increases). This is a trade off. But, productivity dominates the economics, so most producers try to run at the highest feasible pressures.
[0074] For bitumen SAGD, we expect recoveries of about 50 to 70% OBIP and the residual bitumen in the steam-swept chamber to be about 10 to 20% of the pore volume, depending on steam temperatures ( FIG. 19 ). Since about 1990, SAGD has now become the dominant in situ process to recover Canadian bitumen and the production growth is exponential ( FIG. 20 ). Canada has now exceeded USA EOR steam heavy oil production and it is the world leader.
[0075] The current SAGD process is still similar to the original concept, but there are still expectations of future improvements ( FIG. 21 ). The improvements are focused on 2 areas—using steam additives (solvents or non-condensable gases) e.g. Gates (2005) or improvements/alterations in SAGD geometry (Sullivan (2010), Kjorholt (2010), Gates (2010)).
2.2 In Situ Combustion (ISC)
[0076] In situ combustion (ISC) started with field trials in the 1950's (Ramey (1970)). ISC was the “holy grail” of EOR, because it was potentially the low-cost process. Early applications were for medium and heavy oils (not bitumen), where the oil had some in situ mobility. A simple vertical well was used to inject compressed air that would “push” out heated oil toward a vertical production well. The first version of ISC was dry combustion using only compressed air as an injectant (Gates (1977)) ( FIG. 24 ). A combustion-swept zone is behind the combustion front. Downstream of the combustion front, in order, is a vaporizing zone with oil distillate and superheated steam, a condensing zone where oil and steam condense and an oil bank that is “pushed” by the injectant gas toward a vertical production well. The vaporizing zone fractionates oil and pyrolyzes the residue to produce a “coke” that is consumed as the combustion fuel.
[0077] Another version of ISC also emerged, called wet combustion or COFCAW. After a period of dry combustion, liquid water was injected with compressed air (or alternating injection). The idea was that water would capture heat inventoried in the combustion-swept zone to produce steam prior to the combustion front. This would improve productivity and efficiency (Dietz (1968), Parrish (1969), Craig (1974)). FIG. 31 shows how wet combustion worked, using the same simple vertical well geometry as dry combustion. A liquid water zone precedes the combustion-swept zone, otherwise the mechanisms are similar to dry ISC as shown in FIG. 24 . The operator of a wet combustion process has to be careful not to inject water too early in the process or not to inject too much water, or the water zone can overtake the combustion front and quench HTO combustion.
[0078] The principles of dry and wet ISC were well known in the early days (Doschner (1966), Ramey (1970), Chu (1977)). The mechanisms were well documented. It was also recognized that these were two kinds of in situ combustion—low temperature oxidation (LTO), from about 150 to 300° C., where oxidation is incomplete, some oxygen can break through to the production well, organic compounds containing oxygen are formed, acids and emulsions are produced and the heat release per unit oxygen injected is lower; and high temperature oxidation (HTO), from about 400 to 800° C. where most (all) oxygen is consumed to produce combustion gases (CO 2 , CO, H 2 O . . . ) and the heat release per unit oxygen consumed is maximized. It was generally agreed that HTO was desirable and LTO was undesirable (Butler (1991)). [For Athabasca bitumen, LTO is from 150 to 300° C. and HTO is from 380 to 800° C. (Yang (2009(2))]. A screening guide for ISC (Chu (1977)) (φ>0.22, S o >50%. φ S o >0.13, API<24, μ<1000 cp.) indicates that ISC, using vertical-well geometry, is best applied to heavy or medium oils, not bitumen.
[0079] Despite decades of field project trials, ISC has only seen limited success, for a variety of reasons. In a 1999 DOE review (Sarathi (1999)), more than half of the North American field tests of ISC were deemed “failures”. By the turn of the century the total world ISC projects dropped to 28 (Table 12).
[0080] ISC using oxygen or enriched air (ISC(O 2 )) was attempted in a few field projects. In the 1980's “hey day” for EOR, there were 10 ISC(O 2 ) projects active in North America—4 in the USA and 6 in Canada (Sarathi (1999)). The advantages of using oxygen were purported as higher energy injectivity, production of near-pure CO 2 gas as a product of combustion, some CO 2 solubility in oil to reduce viscosity, sequestration of some CO 2 , improved combustion efficiency, better sweep efficiency and reduced GOR for produced oil. The purported disadvantages of using oxygen were safety, corrosion, higher capital costs and LTO risks (Sarathi (1999), Butler (1991)).
[0081] Only a few tests of ISC were undertaken for bitumen recovery using vertical well geometries. For a true bitumen (>100,000 c.p in situ viscosity) gas injectivity (air or oxygen) is very poor. So, even though bitumen is very reactive and has lower HTO and LTO temperatures than other oils and HTO can be sustained at very low oxygen/air flux rates ( FIG. 25 ), bitumen ISC EOR processes are very difficult. New well geometries using horizontal wells, with short paths for bitumen recovery and perhaps a gravity drainage recovery mechanism, can improve the prospects for bitumen ISC EOR.
[0082] One such process that is currently field testing is the THA1 process using a horizontal production well and horizontal or vertical air injector wells ( FIG. 22 , Graves (1996), Petrobank (2009)). So far, success has been only limited. Another geometry is shown in FIG. 23 for the COSH or COGD process (New Tech. Magazine (2009)).
[0083] Others (Moore 1999, Javad (2001), Belgrave (2007)) have proposed to conduct bitumen ISC in the steam-swept gravity drainage chamber produced by a SAGD process, using the residual bitumen in the steam-swept zone as ISC fuel after the SAGD process has matured or reached its economic limit. These studies have concluded that ISC is feasible for these conditions.
2.3 Steam+Oxygen
[0084] It may be considered that COFCAW (water+air/oxygen injection for ISC) may be similar to steam+oxygen processes. ISC using COFCAW and air or oxygen could create steam+oxygen or steam+CO 2 mixtures when water was vaporized in the combustion-swept zone prior to (or after) the combustion front. But, if we have a modern geometry suited to bitumen recovery, we have short paths between wells. If liquid water is injected we would have a serious risk of quenching HTO reactions. COFCAW works for vertical well geometries (eg. Parrish (1969)) because of the long distance between injector and producer and the ability to segregate liquid water from the combustion zone until it is vaporized.
[0085] There is not much literature on steam+oxygen, but steam+CO 2 has been considered for EOR for some time. Assuming we have good HTO combustion, a steam+oxygen mixture will produce a steam+CO 2 mixture in the reservoir. Also, there has been some focus to produce steam+oxygen or steam+flue gas mixtures using surface or down hole equipment (Balog (1982), Wylie (2010), Anderson (2010)). Carbon dioxide can improve steam-only processes by providing other mechanisms for recovery—e.g. Solution gas drive or gas drive mechanisms. For example, steam+CO 2 was evaluated by Balog (1982) for a CSS process, using a mathematical simulation model. Compared to steam, steam+CO 2 (about 9% (v/v) CO 2 ) improved productivity by 35 to 38%, efficiency (OSR) by 49 to 57% and showed considerable CO 2 retention in the reservoir—about 1.8 MSCF/bbl. heavy oil after 3 CSS cycles.
[0086] There have only been a few studies of steam+CO 2 . Combustion tube tests have been performed using mixtures of steam and oxygen (Moore (1994) (1999)). The results have been positive, showing good HTO combustion, even for very low oxygen concentrations in the mixture ( FIG. 28 ). The combustion was stable and more complete than other oxidant mixes ( FIG. 29 ). Oxygen concentrations in the mix varied from just under 3% (v/v) to over 12% (v/v).
[0087] Yang ((2008) (2009(1)) proposed to use steam+oxygen as an alternative to steam in a SAGD process. The process was simulated using a modified STARS simulation model, incorporating combustion kinetics. Yang demonstrated that for all oxygen mixes, the combustion zone was contained in the gas/steam chamber, using residual bitumen as a fuel and the combustion front never intersected the steam chamber walls. FIG. 30 shows production forecasts using steam+oxygen mixtures varying from 0 to 80% (v/v) oxygen. But, the steam/gas chamber was contained with no provision to remove non-condensable gases. So, back pressure in the gas chamber inhibited gas injection and bitumen production, using steam+oxygen mixtures, was worse than steam-only (SAGD) performance ( FIG. 30 ). Also, there was no consideration of the corrosion issue for steam+oxygen injection into a horizontal well, nor was there any consideration of minimum oxygen flux rates to initiate and sustain HTO combustion using a long horizontal well for O 2 injection.
[0088] Yang ((2008), 2009(1)) also proposed an alternating steam/oxygen process as an alternative to continuous injection of steam+O 2 mixes. But, issues of corrosion, minimum oxygen flux maintenance, ignition risks and combustion stability, were not addressed.
[0089] Bousard (1976) proposed to inject air or oxygen with hot water or steam to propogate LTO combustion as a method to inject heat into a heavy oil reservoir. But HTO is desirable and LTO is undesirable, as discussed above.
[0090] Pfefferle (2008) suggested using oxygen+steam mixtures in a SAGD process, as a way to reduce steam demands and to partially upgrade heavy oil. Combustion was purported to occur at the bitumen interface (the chamber wall) and combustion temperature was controlled by adjusting oxygen concentrations. But, as shown by Yang, combustion will not occur at the chamber walls. It will occur inside the steam chamber, using coke produced from residual bitumen as a fuel not bitumen from/at the chamber wall. Also, combustion temperature is almost independent of oxygen concentration (Butler, 1991). It is dependant on fuel (coke) lay down rates by the combustion/pyrolysis process. Pfefferle also suggested oxygen injection over the full length of a horizontal well and did not address the issues of corrosion, nor of maintaining minimum oxygen flux rates if a long horizontal well is used for injection.
[0091] Pfefferle, W. C. “Method for CAGD Recovery of Heavy Oil” US Pat. 2007/0187094 A1, Aug. 16, 2007 describes—a process similar to SAGD to recover heavy oil, using a steam chamber. There are 2 versions described. The first version, injects a steam+oxygen mixture using a SAGD steam injector well. The second version injects oxygen into a new horizontal well, parallel to the SAGD well pair, but completed in the upper part of the reservoir. With the separate oxygen injector, steam is injected into the reservoir from the upper SAGD well to limit access of oxygen to the lower SAGD producer. Pfefferle (2007) proposes combustion occurs at the chamber walls (i.e. the steam-cold bitumen interface) and that temperature of combustion can be controlled by changing oxygen concentrations. It is proposed to increase combustion temperatures at the chamber walls sufficiently to crack and upgrade the oil.
[0092] But Pfefferle (2007)
[0093] (1) doesn't focus on bitumen but uses the term oil or heavy oil.
[0094] (2) there is no provision to remove non-condensable gases produced by combustion
[0095] (3) except for the second version of the process, oxygen and steam are not segregated to control/minimize corrosion
[0096] (4) there is no consideration for a preferred range of oxygen/steam ratios or oxygen concentrations
[0097] (5) in both cases oxygen injection is spread out over a long horizontal well. In the first case oxygen is also diluted with steam. There is no consideration to limiting oxygen-reservoir contact to ensure and control oxygen flux rates.
[0098] Pfefferle (2007) alleges that combustion will occur at the steam chamber wall (claims 1 , 2 , 7 , 9 ). In reality this will never occur. Combustion will always occur in the steam-swept zone, using a coke fraction of residual bitumen as a fuel. Even without steam injected, a steam-swept zone will be formed using connate water from the reservoir. The combustion zone will always be far away from the steam chamber walls.
[0099] Pfefferle (2007) also alleges that the combustion temperature can be adjusted by changing the oxygen concentration (claims 2 , 7 , 9 ). This is not possible. Combustion temperature is controlled by the coke concentration in the matrix where combustion occurs. This has been confirmed by lab combustion tube tests. Combustion temperatures are substantially independent of oxygen concentration at the combustion site.
[0100] Finally Pfefferle (2007) also alleges that temperature at the chamber walls can be controlled by oxygen concentration (claims 7 , 9 ) even to the extent of cracking and upgrading oil at the walls.
[0101] In view of the discussion above, this will not happen.
[0102] Pfefferle, W. C. “Method for In Situ Combustion of In-Place Oils”, U.S. Pat. No. 7,581,587 B2, Sep. 1, 2009 describes a geometry for dry in situ combustion using a vertical well and a horizontal production well. The vertical well has a dual completion and is located near the heel of the production well. The lower completion in the vertical well is near the horizontal producer and is used to inject air for ISC. The concentric upper completion is near the top of the reservoir and is used to remove non-condensable gases produced by combustion. Production is adjusted so the lower horizontal well is full of liquids (oil+water) at all times. The bleed well (gas removal well) may also have a horizontal section. Multiple bleed wells are also proposed. This is a heel-to-toe process. Most ISC processes using horizontal producers (eg THA1) are toe-to-heel processes. This process is for dry ISC and really doesn't apply to SAGDOX except, perhaps, for well configurations.
[0103] None of the SAGDOX versions described herein are for heel-to-toe processes. SAGDOX always has steam injection. Pfefferle doesn't discuss steam as an additive or as an option.
[0104] There exists therefore a long felt need to provide an effective SAGDOX process which is energy efficient and can be utilized to recover bitumen from a reservoir over a number of years until the reservoir is depleted.
[0105] It is therefore a primary object of the invention to provide a SAGDOX process wherein oxygen and steam are injected separately into a bitumen reservoir.
[0106] It is a further object of the invention to provide at least one well to vent produced gases from the reservoir to control reservoir pressures.
[0107] It is yet a further object of the invention to provide production wells extending a distance of greater than 1000 metres.
[0108] It is yet a further object of the invention to provide oxygen at an amount of substantially 35% (v/v) and corresponding steam levels at 65%.
[0109] It is yet a further object of the invention to provide oxygen and steam from a local cogeneration and air separation unit located proximate a SAGDOX process.
[0110] Further and other objects of the invention will be apparent to one skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.
SUMMARY OF THE INVENTION
[0111] According to a primary aspect of the invention there is provided a process to recover hydrocarbons from a hydrocarbon reservoir, namely bitumen (API<10; in situ viscosity>100,000 c.p.), said process comprising;
[0112] establishing a horizontal production well in said reservoir;
[0113] separately injecting an oxygen-containing gas and steam continuously into the hydrocarbon reservoir to cause heated hydrocarbons and water to drain, by gravity, to the horizontal production well, the ratio of oxygen/steam injectant gases being controlled in the range from 0.05 to 1.00 (v/v).
[0114] removing non-condensable combustion gases from at least one separate vent-gas well, which is established in the reservoir to avoid undesirable pressures in the reservoir.
[0115] In one embodiment steam is injected into a horizontal well of the same length as the production well, and parallel to said production well with a separation of 4 to 10 m, directly above the production well using for example a typical SAGD geometry.
[0116] Preferably vertical oxygen injection and vent gas wells are established in the reservoir.
[0117] In another embodiment said vertical wells for oxygen injection and vent gas removal are not separate wells but tubing strings are inserted within the existing horizontal steam injection well proximate the vertical section of the well, and packers are used to segregate oxygen injection and/or vent-gas venting.
[0118] Preferably the oxygen-containing gas has an oxygen content of 95 to 99.9% (v/v). In another embodiment oxygen-containing gas is enriched air with an oxygen content of 20 to 95% (v/v).
[0119] In another embodiment oxygen-containing gas has an oxygen content of 95 to 97% (v/v). Alternatively the oxygen-containing gas is air.
[0120] In one embodiment said process further comprises an oxygen contact zone portion of the well within the reservoir less than 50 m long and said zone being implemented by aspects therein selected from perforations, slotted liners, and open holes.
[0121] In another embodiment the horizontal wells are part of an existing SAGD recovery process and incremental SAGDOX wells, for oxygen injection and for non-condensable vent gas removal, are added subsequent to SAGD operation.
[0122] In another embodiment said process further comprises a SAGDOX process that is started up by operating a horizontal well pair in the SAGD process and subsequently circulating steam in incremental SAGDOX wells until all the wells are communicating, prior to starting oxygen injection and vent gas removal.
[0123] Preferably the SAGDOX process is started by circulating steam in all wells until all the wells are communicating, prior to starting oxygen injection and vent gas removal.
[0124] In another embodiment a SAGDOX process is controlled and operated by steps selected from:
i. Adjusting steam and oxygen flows to attain a predetermined; oxygen/steam ratio and energy injection rate targets, ii. Adjusting vent gas removal rates to control process pressures and to improve/control conformance, iii. Controlling bitumen and water production rates to attain sub-cool targets, assuming fluids close to the production well are steam-saturated (steam trap control).
[0128] Steam trap control (also called sub cool control) for steam EOR or SAGDOX is used to control the production well rate so that only liquids (bitumen and water) are produced, not steam or other gases. The way this is done is as follows:
[0129] (1) it is assumed that the region around the well is predominantly saturated steam. For SAGD this is easy since steam is the only injectant. For SAGDOX this means that noncondesable gases produced from combustion are near the top of the reservoir away from the production well. This has been confirmed by several lab tests and some field tests.
[0130] (2) pressure is measured either at the steam injection well or at the production well. Saturated steam T is calculated using the measured pressure.
[0131] (3) the production well fluid production rate is controlled (pump or gas lift rates) so that the average T (or heel T) is less than the saturated steam T calculated, usually by 10 to 20 C of sub cool.
[0132] Preferably oxygen/steam ratios start at about 0.05 (v/v) and ramp up to about 1.00 (v/v) as the process matures.
[0133] In a preferred embodiment the oxygen/steam ratio is between 0.4 and 0.7 (v/v).
[0134] Preferably when SAGDOX is implemented the horizontal well length of the pattern is extended when compared to an original SAGD design.
[0135] In one example the horizontal well length extends beyond 1000 m.
[0136] In one embodiment the process further comprises conversion of a mature SAGD project whereat adjacent patterns are in communication, to a SAGDOX project using 3 adjacent patterns where the steam injector of the central pattern is converted to an oxygen injector and the injector wells of the peripheral patterns are continued to be used as steam injectors.
[0137] Preferably the oxygen/steam ratio is between 0.05 and 1.00 (v/v). Preferably the gases are produced, as separate streams, by an integrated ASU: Cogen Plant.
[0138] In another embodiment further process steps are selected from:
i. The ratio of oxygen/steam is between 0.4 and 0.7 (v/v), ii. The oxygen purity in the oxygen-containing gas is between 95 and 97% (v/v), iii. Steam and oxygen are produced in an integrated ASU: Cogen plant, iv. The oxygen contact zone with the reservoir is less than 50 m.
[0143] In another preferred embodiment of the process the oxygen injection well is no more than 50 m. of contact with the reservoir, to avoid oxygen flux rates dropping to less than that needed to start ignition or to sustain combustion.
[0144] In a further preferred embodiment of the process steam provides energy directly to the reservoir and oxygen provides energy by combusting residual bitumen (coke) in the steam chamber whereat the combustion zone is contained; residual bitumen being heated, fractionated and finally pyrolyzed by hot combustion gases, to make coke, the actual fuel for combustion.
[0145] Preferably the bitumen and water production well is controlled assuming saturated conditions using steam-trap control, without producing significant amounts of live steam, non-condensable combustion gases or unused oxygen.
[0146] In another embodiment the steam-swept zone of the steam chamber in a SAGDOX process further comprises;
[0147] a combustion-swept zone with substantially zero residual bitumen and connate water,
[0148] a combustion front,
[0149] a bank of bitumen heated by combustion gases,
[0150] a superheated steam zone,
[0151] a saturated-steam zone, and
[0152] a gas/steam bitumen interface or chamber wall where steam condenses and releases latent heat.
[0153] In one embodiment:
[0154] bitumen drains, by gravity, from a hot bitumen bank and from a bitumen interface,
[0155] water drains, by gravity, from a saturated steam zone and from the bitumen interface, and
[0156] energy (heat) in the hot bitumen and in the superheated-steam zone is partially used to reflux some steam. The fuel for combustion and the source of bitumen in the hot bitumen zone is residual bitumen in the steam-swept zone, combustion being contained inside of the steam chamber and preferably wherein hot combustion gases transfer heat to bitumen, in addition to steam mechanisms.
[0157] In another embodiment carbon dioxide, produced as a combustion product, can dissolve into bitumen and reduce viscosity.
[0158] In an alternative embodiment oxygen purity is reduced to substantially the 95-97% range whereat energy needed to produce oxygen from an ASU drops by about 25% and SAGDOX efficiencies improve significantly.
[0159] In a preferred embodiment of the process the SAGDOX process uses water directly as steam is injected, but it also produces water directly from 2 sources, namely water produced as a combustion product and connate water vaporized in the combustion-swept zone.
[0160] Preferably the maximum oxygen/steam ratio is 1.00 (v/v) with an oxygen concentration of 50.0%.
[0161] In another embodiment of the process as a SAGDOX process matures, the combustion front will move further away from the oxygen injector and requires increasing oxygen rates to sustain High Temperature Oxidation reactions.
[0162] Preferably the SAGDOX gas mix is between 20 and 50% (v/v), oxygen in the steam/oxygen mixture.
[0163] More preferably the SAGDOX gas mix is 35% oxygen (v/v), oxygen in the steam/oxygen mixture.
[0164] In a preferred embodiment the oxygen injection point needs to be preheated to about 200° C. so oxygen will spontaneously react with residual fuel.
[0165] According to yet another aspect of the invention there is provided a method of starting up of a SAGDOX process described herein comprising the following steps:
1. Start oxygen injection and reduce steam flow to achieve a proscribed oxygen concentration target at the same energy rates as SAGD, 2. as reservoir pressures approach a target pressure, partially open one (or more) produced gas (PG) removal wells to remove non-condensable combustion gases and to control P, 3. If split/multiple PG wells are provided adjust PG removal rates to improve/optimize O 2 conformance, 4. If oxygen gas is present in PG removal well gas, the well should be choked back or shut in, 5. If non-condensable gas (CO 2 , CO, O 2 . . . ) is present in the horizontal producer fluids, the production rate should be slowed and/or oxygen conformance adjusted and/or PG removal rates increased.
BRIEF DESCRIPTION OF THE FIGURES
[0171] FIG. 1 is a SAGD Geometry.
[0172] FIG. 2 is a SAGD Production Simulation.
[0173] FIG. 3 is a SAGDOX Geometry 1.
[0174] FIGS. 3A through 3E provide additional details of SAGDOX geometry regarding FIG. 3 .
[0175] FIG. 4 is a SAGDOX Bitumen Saturation Schematic.
[0176] FIG. 5 is a SAGDOX Geometry 2.
[0177] FIG. 6 is a SAGDOX Geometry 3.
[0178] FIG. 7 is a SAGDOX Geometry 4.
[0179] FIG. 8 is a SAGDOX Geometry 5.
[0180] FIG. 9 is a SAGDOX Geometry 6.
[0181] FIG. 10 is a SAGDOX Geometry 7.
[0182] FIG. 11 is a SAGDOX Geometry 8.
[0183] FIG. 12 is a SAGDOX Geometry 9.
[0184] FIG. 13 is a SAGD Hydraulic Limits.
[0185] FIG. 14 is a SAGD/SAGDOX Pattern Extension.
[0186] FIG. 15 is a SAGDOX—3 well-pair pattern.
[0187] FIG. 16 is a Cogen Electricity Production (Cogen/ASU).
[0188] FIG. 16A is a schematic representation of an integral ASU & COGEN for a SAGDOX process.
[0189] FIG. 17 is a SAGD Steam Chamber.
[0190] FIG. 18 is SAGD stages.
[0191] FIG. 19 is a Residual Bitumen in Steam-Swept Zones.
[0192] FIG. 20 is a SAGD Production History.
[0193] FIG. 21 is SAGD Technology.
[0194] FIG. 22 is the THA1 Process.
[0195] FIG. 23 is COSH, COGD Processes.
[0196] FIG. 24 is an In situ Combustion Schematic.
[0197] FIG. 25 is ISC Minimum Air Flux Rates.
[0198] FIG. 26 is CSS using Steam+CO 2 : Production.
[0199] FIG. 27 is CSS using Steam+CO 2 : Gas Retention (9% CO 2 in steam mix).
[0200] FIG. 28 is Steam+Oxygen Combustion Tube Tests I.
[0201] FIG. 29 is Steam+Oxygen Combustion Tube Tests II.
[0202] FIG. 30 is SAGD using Steam+Oxygen mixes.
[0203] FIG. 31 is a Wet ISC.
DETAILED DESCRIPTION OF THE INVENTION
Problems Solved
3.1 SAGD Problems
[0000]
(1) Steam is costly
(2) SAGD uses a lot of water (0.25 to 0.50 bbl water/bbl bitumen)
(3) Production well (bitumen+water) pressure gradients can limit SAGD productivity and energy (steam) injectivity. For a typical horizontal well length of 1000 m., using a typical tubing/pipe sizes fluid productivity is limited to about 4000 bbl/d, otherwise the liquid/gas interface (steam/water) can flood the toe of the steam injector and/or steam can break through to the producer heel. Alternately for the above production rates, the effective well length is limited to about 1000 m, so the pattern size is also limited. If the well separation is increased from say 5 to 10 meters, the effective well length (or injectivity) can be increased, but the start up period is prolonged significantly. If well/pipe sizes are increased to increase well length or injectivity, capital costs and heat losses are increased.
(4) Carbon dioxide emissions from SAGD steam boilers are significant (about 0.08 tonnes CO 2 /bbl bitumen). The emitted CO 2 is not easily captured for sequestration. It is diluted in boiler flue gas, or in cogen flue gas.
(5) Steam cannot be economically transported for more than about 5 miles. A central steam plant can only service a limited area.
(6) SAGD is a steam-only, saturated-steam process. Temperature is determined by operating pressure
(7) SAGD cannot mobilize connate water by vaporization.
(8) SAGD cannot reflux steam/water in the reservoir. It is a once-through water process.
(9) SAGD, in the steam-swept zone, leaves behind (not recoverable) 10 to 20% (v/v) of the pore volume as residual bitumen.
(10) When SAGD reaches its economic limit, zones of unswept reservoir (“wedge oil”) are not recovered.
(11) If we measure energy efficiency as the percentage of net energy produced, considering energy used on the surface to produce bitumen and the fuel value of the bitumen produced, SAGD is relatively inefficient.
3.2 SAGDOX Problems
[0000]
(1) Mixtures of saturated steam and oxygen are very corrosive to carbon steel and other alloys. New wells or a segregation system are needed to keep oxygen and steam separated prior to injection into the reservoir.
(2) One suggestion (Yang (2009)) is to use the SAGD steam injector well for alternating volumes of steam and oxygen. But to sustain HTO combustion we need a constant supply and a minimum flux of oxygen, otherwise we will breakthrough oxygen to producer wells or start LTO combustion.
(3) It has also been suggested (Yang (2009), Pfefferle (2008)) that we can simply mix oxygen with steam and use the horizontal steam injector for SAGD. Aside from severe corrosion issues noted above (1), oxygen flux rates are a concern. If oxygen is mixed with steam and injected in a horizontal well, oxygen flux is diluted over the length of the horizontal well (˜1000 m.) Flux of oxygen, in some areas, may be too low to initiate and sustain HTO combustion. Even if average flux rates are satisfactory, inhomogeneities in the reservoir may cause some areas to be depleted in oxygen. As a result, oxygen breaks through to production wells or low flux oxygen can result in LTO oxidation.
(4) Separate control of oxygen and steam rates is needed to adjust energy input rates and relative contributions from each component.
(5) Oxygen needs to be injected, at first, into (or near to) a steam-swept zone, so combustion of residual fuel components occurs and injectivity is not a serious limit. The zone also needs to be preheated (at start-up) so spontaneous HTO ignition occurs (not LTO).
(6) The well configuration should ensure that oxygen (and steam) is mostly contained within the well pattern volume.
(7) If new SAGDOX wells are too far away from the steam-swept zone, start-up time to transition from SAGD to SAGDOX can be prolonged. Because SAGDOX energy is less costly than SAGD, it is desirable to start SAGDOX quickly.
[0222] How to Shut Down a SAGDOX Process
[0223] Since oxygen is much less costly than steam as a way to provide energy to a bitumen reservoir for EOR and during normal SAGDOX operations we have built up a large inventory of steam in the reservoir, when the process reaches its economic limit (i.e. when oxygen+steam costs=produced bitumen value) the following shut down procedure is suggested:
(1) shut off steam injection (2) continue to inject O2 at previous rates (3) continue to use sub-cool control for the production well (4) when the process reaches its new economic limit (when O2 cost=produced bitumen value) shut in the oxygen injector (5) continue to produce bitumen until production rates fall below a predetermined target (eg 10 bbls/d)
[0229] SAGDOX Technical Description
4.1 SAGD Simulation
[0230] SAGD is a process that uses 2 parallel horizontal wells separated by about 5 m., each up to about 1000 m. long, with the lower horizontal well (the bitumen+water producer) about 2 to 8 m. above the bottom of the reservoir (see FIG. 1 ). After a startup period where steam is circulated in each well to attain communication between the wells, steam is injected into the upper horizontal well and bitumen+water are produced from the lower horizontal well.
[0231] We have simulated a SAGD process using the following assumptions:
(1) A homogeneous sandstone (or sand) reservoir containing bitumen (2) Generic properties for an Athabasca bitumen (3) 25 m homogeneous pay zone (4) 800 m. SAGD well pair at 100 m spacing, with 5 m spacing between the parallel horizontal wells (5) 10° C. sub cool for production control (i.e. produced fluids are 10° C. lower than saturated-steam T at reservoir P) (6) 2 MPa pressure for injection control (7) 4 mos. steam circulation prior to SAGD start-up (8) Discretized well-bore model
[0240] The simulation production is shown in FIG. 2 . The economic limit is taken as SOR=9.5 at the end of year 10. The following are highlights of the simulation:
(1) Bitumen recovery=33.6 km 3 =2.099 MM bbl (2) Avg. bitumen productivity=575 bbl/d (3) Steam used=1124.9 km 3 =7.078 MM bbl=2.477×10 12 BTU (4) Avg. steam rate=1939 bbl/d (5) Avg. SOR=3.37; avg. ETOR (Energy to Oil Ratio)=1.180 MMBTU/bbl (6) Recovery factor=63.4%/OBIP (7) OBIP for pattern=3.31 MM bbl
[0248] We will use these results as the basis for SAGDOX comparison.
4.2 SAGDOX
[0249] SAGDOX is a bitumen EOR process using horizontal wells, similar to SAGD, for steam injection and for bitumen+water production, with extra vertical wells to inject oxygen gas and to remove non-condensable combustion gases ( FIG. 3 ). Steam and oxygen are injected separately and continuously into a bitumen reservoir as sources of energy. Table 1 summarizes properties of steam/oxygen mixes, assuming 1000 BTU/lb steam and 480 BTU/SCF oxygen (Butler, 1991) used for in-situ combustion. The heat assumptions include heat released directly to the reservoir and heat recovered from produced fluids, assuming that produced fluid heat recovery is useful. The reservoir is preheated by steam either by conducting a SAGD process in the horizontal wells or by steam circulation in the SAGDOX extra wells, until communication is established between the wells. Then oxygen and steam are introduced in separate or segregated injectors, otherwise corrosion can be a problem. The oxygen injection well (or segregated section) should be no more than 50 m. of contact with the reservoir, otherwise oxygen flux rates can drop to less than that needed to start ignition or to sustain combustion ( FIG. 25 ). Steam provides energy directly to the reservoir. Oxygen provides energy by combusting residual bitumen (coke) in the steam chamber. The combustion zone is contained within the steam chamber. Residual bitumen is heated, fractionated and finally pyrolyzed by hot combustion gases, to make coke that is the actual fuel for combustion. A gas chamber is formed containing injected steam, combustion gases, refluxed steam and vaporized connate (formation) water. Heated bitumen drains from the gas chamber (residual bitumen) and from the chamber walls. Condensed steam drains from the saturated steam area and from the chamber walls. Condensed water and bitumen are collected by the lower horizontal well and conveyed (or pumped) to the surface. Please see FIGS. 3A through D in this regard.
[0250] FIG. 3 shows one geometry suitable for SAGDOX. A SAGD horizontal well pair (wells 1 and 2 ) has been augmented by 3 new vertical SAGDOX wells—2 wells to remove non-condensable combustion gases (wells 3 and 4 ) and a separate oxygen injection well (well 5 ). The vertical gas-remover wells are on the pattern boundary and are shared by neighbor patterns (i.e. only 1 net well). An oxygen injection well (well 5 ) is near the SAGD toe, and completed low enough in the pay zone to ensure that oxygen injection is into a steam-swept zone.
[0251] The produced gas removal wells are operated separately to control conformance and reservoir pressure, while minimizing production of steam and/or unused oxygen. Oxygen and steam injection are controlled to attain oxygen/steam ratio targets (oxygen “concentration”) and energy injection rates. The bitumen+water production well is controlled assuming saturated conditions using steam-trap control, without producing significant amounts of live steam, non-condensable combustion gases or unused oxygen.
[0252] The SAGDOX process may be considered as a SAGD process using wells 1 and 2 and a simultaneous in situ combustion (ISC) process using wells 3 , 4 and 5 . Of course the geometry shown in FIG. 3 is not the only alternative for SAGDOX (see 4.10).
4.3 Oxidation Chemistry
[0253] SAGDOX creates some energy in a reservoir by combustion. The “coke” that is prepared by hot combustion gases fractionating and pyrolyzing residual bitumen, can be represented by a reduced formula of CH. 5 . This ignores trace components (S, N, O . . . etc.) and it doesn't imply a molecular structure, only that the “coke” has a H/C atomic ratio of 0.5.
[0254] Let's assume:
(1) CO in the product gases is about 10% of the carbon combusted (2) Water-gas-shift reactions, occur in the reservoir
[0000] CO+H 2 O→CO 2 +H 2 +HEAT
[0257] This reaction is favored by lower T (lower than combustion T) and high concentrations of steam (i.e. SAGDOX). The heat release is small compared to combustion.
[0258] Then our net combustion stoichiometry is determined as follows:
[0000] Combustion: CH 0.5 +1.075O 2 →0.9CO 2 +0.1CO+0.25H 2 O+HEAT
[0000] Shift: 0.1CO+0.1H 2 O→0.1CO 2 +0.1H 2 +HEAT
[0000] Net: CH 0.5 +1.075O 2 →CO 2 +0.1H 2 +0.15H 2 O+HEAT
[0259] Features are as follows:
(1) Heat release=480 BTU/SCF O 2 (Butler, 1991) (2) Non-condensable gas make=102% of oxygen used (v/v) (3) Combustion water make=14% of oxygen used (v/v) (net) (4) Hydrogen gas make=9.3% of oxygen used (v/v) (5) Produced gas composition ((v/v) %):
[0000]
Wet
Dry
CO 2
80.0
90.9
H 2
8.0
9.1
H 2 O
12.0
—
Total
100.0
100.0
(6) combustion temperature is controlled by “coke” content. Typically HTO combustion T is between about 400 and 800° C. (Yang (2009(2))).
4.4 SAGDOX Mechanisms/Productivity
[0266] SAGDOX injects both steam and oxygen gas. Each can deliver heat to a bitumen reservoir. Table 1 shows the properties of various steam+oxygen “mixtures”. The term “mixture” doesn't imply that we inject a mixture or that we have expectations of good mixing in the reservoir. It is only a convenient way to label the net properties of separately injected steam and oxygen gases. We use the terminology SAGDOX (z), where z is the percentage concentration (v/v) of oxygen gas in the steam+oxygen “mixture”.
[0267] The mechanisms of SAGDOX are important factors to assess expected productivity of the process. FIG. 4 shows a plot of bitumen saturation, perpendicular to the horizontal well plane, about half-way in the net pay zone, for a mature SAGDOX process, based on a simulation (Yang, (2009(1)). The plot shows the extra process mechanisms of SAGDOX compared to SAGD. In addition to a steam-swept zone (steam chamber) SAGDOX has a combustion-swept zone with zero residual bitumen and no connate water, a combustion front, a bank of bitumen heated by combustion gases, a superheated steam zone, a saturated-steam zone, and a gas/steam bitumen interface (chamber wall) where steam condenses and releases latent heat. Bitumen drains, by gravity, from the hot bitumen bank and from the bitumen interface. Water drains, by gravity, from the saturated steam zone and from the bitumen interface. Energy (heat) in the hot bitumen and in the superheated-steam zone is partially used to reflux some steam.
[0268] In one dimension, ( FIG. 4 ) the hot bitumen bank appears as a spike; in two dimensions, for a homogeneous reservoir, it appears as a circle (halo), and; in three dimensions, it appears as a sphere. The fuel for combustion and the source of bitumen in the hot bitumen zone is residual bitumen in the steam-swept zone. The combustion is contained inside of the steam chamber.
[0269] Water/steam is an important factor for heat transfer. Compared to hot non-condensable gases, steam has two important advantages to transfer heat—it contains much more energy because of latent heat and when it condenses it creates a transient-low pressure area to help draw in more steam.
[0270] Taking these mechanisms into account, the following issues can potentially decrease productivity for SAGDOX compared to SAGD:
(1) We inject less steam directly compared to SAGD steam injection (2) Particularly, in the saturated-steam zone of SAGDOX, steam is diluted by combustion gases and the steam partial-pressure is reduced, reducing temperatures compared to SAGD. Lower temperatures at the bitumen interface, increase the heated bitumen viscosity and reduce drainage rates. (3) Non-condensable gases can block steam access to the cold bitumen interface (4) Some heat (steam) will be removed from the process in the produced-gas removal wells ( FIG. 3 ) (5) The flow patterns (e.g. convection) can be disrupted by non-condensable gases and harm conformance.
[0276] On the other hand, for the same energy injection, SAGDOX productivity, compared to SAGD, can be improved by the following:
(1) Extra steam, in addition to injected steam, is produced by vaporizing connate water and as a product of combustion. (2) Since combustion temperature (380-800° C.) is greater than saturated-steam temperature (200-250° C.), on average some steam/water will be refluxed. (Table 6 shows how much reflux is needed to maintain steam inventories similar to SAGD). (3) Hot combustion gases can transfer heat to bitumen, in addition to steam mechanisms. (4) A hot bitumen bank is created near the combustion front ( FIG. 4 ), sourcing residual bitumen left behind by the steam-swept zone. This bitumen can drain to the production well, add to productivity and it can contribute to steam reflux. (5) Separate control of oxygen injection and combustion gas removal can improve conformance (or minimize the damage of poorer conformance). (6) Carbon dioxide, produced as a combustion product, can dissolve into bitumen and reduce viscosity. (7) Top-down gas drive and solution gas drive mechanisms can add to productivity. (8) Non condensable gas accumulates at/near the ceiling zone of the gas chamber. This can insulate the ceiling and reduce heat losses.
[0285] The result of combining all these mechanisms is difficult to anticipate. If steam heat transfer is a dominant mechanism, we would expect SAGD to have a higher productivity per unit of energy injected than SAGDOX.
[0286] To reflect this view, Table 2 presents a scenario whereby for the same bitumen productivity, the energy to oil ratio (ETOR) for SAGDOX increases as the oxygen content increases (or as the steam content decreases)—from 1.18 MMBTU/bbl for SAGD to 1.623 MMBTU/bbl for SAGDOX(75). This scenario is used for various comparisons (Tables) herein.
4.5 SAGDOX Well Geometry
[0287] FIG. 3 shows a simple well configuration that is suitable for SAGDOX. The SAGD well pair (well 1 and 2 ) is conventional, with parallel horizontal wells with lengths of 400-1000 m. and separation of 4-6 m. The lower horizontal well is 2-8 m. above the bottom of the bitumen reservoir. The upper well is a steam injector and the lower horizontal well is a bitumen+water producer. Bitumen and condensed steam drain to the lower well, by gravity, from a steam chamber formed above the steam injector ( 1 ). The oxygen injector ( 5 ) is a vertical well that is not at the end of the pattern, but it is about 5 to 20 m, in from the end. The perforated zone is less than 50 m long.
[0288] Two produced gas removal wells ( 3 and 4 ) are on the pattern lateral boundaries toward the heel area of the horizontal well pair. The wells are completed near the top of the reservoir (1 to 10 m. below the ceiling).
[0289] This configuration enables separate control of oxygen and steam injection, separation of oxygen/steam and mixing in the reservoir, oxygen containment in the pattern.
[0290] If oxygen injection is low and/or the reservoir is “leaky” and can contain or disperse some non-condensable gas without pressure build-up, we may not need any produced gas removal wells. FIG. 5 shows such a scheme.
[0291] If start-up is protracted or if we are concerned about retaining oxygen in the well pattern volume, we can inject oxygen near the center of the pattern as shown by well 4 in FIG. 6 . We also don't necessarily need to remove produced gas at the pattern boundaries. FIG. 6 shows produced gas removal wells moved toward the center of the pattern. As an alternate, we can move the gas removal wells to the pattern boundary and share the wells with neighbor patterns ( FIG. 7 ).
[0292] We can also move the gas removal well to the pattern boundary at the end for sharing ( FIG. 8 ) with neighboring patterns.
[0293] We can also have dual purpose wells. FIG. 9 shows an oxygen injector ( 6 ) near the end (toe) of the pattern and a central well ( 5 ) that initially can operate as a produced gas removal well and after the process is established it can be converted to a second oxygen injector for better oxygen conformance control.
[0294] Better O 2 conformance can also be achieved with dual O 2 injectors as shown in FIG. 10 .
[0295] We need not drill new vertical wells for oxygen injection and/or produced gas removal. FIG. 11 shows a packer in the steam injector (well 1 ) to segregate the well toe for oxygen injection in a separate oxygen string. The toe of the horizontal injector well can be sacrificed to corrosion, if the packer is not a good seal, with little consequence.
[0296] FIG. 12 shows another packer segregating part of the vertical rise section of the steam injector (well 1 ) for produced gas removal. This version of the SAGDOX has no new SAGDOX wells.
[0297] Oxygen injection and produced gas removal are small volume applications and need not occupy a lot of the steam injector capacity, especially for lower oxygen concentrations in the steam+oxygen mix.
[0298] Obviously, other geometries are possible using combination of well configurations shown in FIGS. 1,3,5,6,7,8,9,10,11,12 .
4.6 Energy Efficiency
[0299] Let's define EOR energy efficiency as:
[0000] E =[( B−S )/ B]× 100
[0000] Where E=(%) energy efficiency; B=fuel value of bitumen (6 MMBTU/bbl); and S=energy used on the surface to produce bitumen (MMBTU/bbl)
[0300] For SAGD; B=6 and for 85% boiler efficiency and 10% steam distribution losses (75% net efficiency)
[0000] E (SAGD)[(6−ETOR/0.75)/6]×100
[0301] For our SAGD simulation (4.1) our average ETOR=1.18 MMBTU/bbl bit, so our avg SAGD efficiency=73.8%
[0302] For SAGDOX, the efficiency calculation is more complex. The steam component (ETOR(steam)) will be similar to SAGD. If we assume our ASU plant uses 390 kWh/tonne Oz (99.5% purity) and that electricity is produced from a gas-fired combined-cycle power plant at 55% efficiency, then for every MMBTU of gas consumed in the power plant, the oxygen produced (at 480 BTU/SCF) releases 5.191 MMBTU of combustion energy to the reservoir. SAGDOX efficiency is as follows:
[0000] E (SAGDOX)=([6−(ETOR(steam)/0.75)−(ETOR(O 2 )/5.191)]/6)×100
[0303] Table 3 shows the efficiencies for various SAGDOX processes using the energy consumptions of Table 2. The following points are noteworthy:
(1) SAGDOX is more efficient than SAGD for all cases. (2) The efficiency improvement increases with increasing oxygen content in SAGDOX mixtures. (3) The SAGD energy loss is 26%. The equivalent loss for SAGDOX is from 6 to 16%, depending on oxygen content. This is an improvement of 10 to 20% or a factor of 1.6 to 4.3. (4) If we reduce oxygen purity to the 95-97% range (see 5.2), energy needed to produce oxygen from an ASU drops by about 25% and SAGDOX efficiencies improve significantly (see Table 3).
4.7 CO 2 Emissions
[0308] For SAGD and SAGDOX we can expect CO 2 emissions from the following sources:
(1) Boiler Flue Gas—Using methane fuel in air we can expect CO 2 concentrations in flue gas up to 12% (v/v), for a stoichiometric burn. (2) Produced Gas—with oxygen combustion we expect produced gas to be mostly CO 2 , or with a small amount of hydrogen gas. (3) Incineration—Produced gas may (probably) contain some sour gas components (eg. H 2 S). At least, this gas should be incinerated prior to venting. Assuming we use a gas-fired incinerator, we need about 10% of the dry gas volumes as incinerator fuel. This will add to produced gas volumes and add to CO 2 emissions. If we capture produced gas for sequestration or retained in the reservoir, our CO 2 emissions are reduced twice—directly by capture and indirectly by incinerator gas savings. (4) Electricity Use—We use electricity to separate oxygen from air. As an indirect CO 2 source we can consider CO 2 associated with electricity generation. We will assume as gas-fired power plant, using a combined-cycle with an overall 55% efficiency to calculate indirect CO 2 emissions.
[0313] For SAGD we will assume gas-fired boilers at 85% efficiency and a further 10% steam loss in distribution. Then for each MMBTU steam delivered to the reservoir we need 1.333 MMBTU of boiler gas fuel or 1333 SCF/MMBTU of CO 2 emissions or 0.070 tonnes CO 2 /MMBTU.
[0314] Using our previous SAGDOX chemistry (4.3) our CO 2 make is 0.9302 SCF/SCF O 2 or 1937.9 SCF/MMBTU in the reservoir due to combustion or 0.1018 tonnes CO 2 /MMBTU.
[0315] If we also incinerate our produced gases our incremental CO 2 emissions are another 213 SCF/MMBTU (O 2 ).
[0316] Our total direct CO 2 emissions are 2151 SCF/MMBTU (O 2 ) or 0.1130 tonnes/MMBTU (O 2 ). We also have indirect CO 2 from electricity used to make O 2 . If we assume 95-97% O 2 purity our electricity use is 292.5 kWh/tonne O 2 . If we assume a 55% efficient combined cycle plant our CO 2 emissions are 145 SCF CO 2 /MMBTU (O 2 ) or 0.0076 tonnes CO 2 /MMBTU (O 2 ).
[0317] Table 4 shows expected CO 2 emissions for SAGD and various versions of SAGDOX. Table 5 show expected CO 2 emissions if the pure CO 2 streams are captured or sequestered on-site. The following comments are noteworthy:
(1) If we use a worst case assumption—all combustion gas is produced and incinerated and we count indirect CO 2 from electricity use—then the least CO 2 emissions are from SAGD and SAGDOX emissions vary from 142 to 234% of SAGD (2) If we don't include indirect CO 2 , SAGD is still the lowest and SAGDOX varies from 136 to 219% of SAGD (3) If we capture and sequester the “pure” CO 2 vent gas from SAGDOX and back out associated incineration CO 2 increments, then SAGDOX is the lowest CO 2 emitter, from 19 to 58% of SAGD emissions. (4) The lowest emitter, with capture, is SAGDOX (75) with 19% of SAGD CO 2 emissions.
4.8 SAGDOX Water Use/Production
[0322] SAGDOX uses water directly as steam injected, but it also produces water directly from 2 sources—water produced as a combustion product and connate water vaporized in the combustion-swept zone. Our net combustion chemistry (4.3) was:
[0000] CH 0.5 +1.075O 2 →1.0CO 2 +0.15H 2 O+HEAT
[0323] Where CH 0.5 is the reduced formula for coke and hydrogen produced was from shift reactions downstream of the combustion zone (favored by excess steam). The combustion water make is 0.140 SCF/SCF O 2 or 0.0351 bbl/MMBTU (O 2 ).
[0324] If we have a reservoir with 80% initial bitumen saturation, connate water occupies 20% of the pore space. In the steam swept zone with 15 to 20% residual bitumen, per barrel of bitumen produced our connate water is 0.308 to 0.333 bbl/bbl bit. Assuming all the connate water is mobilized by combustion, we will produce 0.31 to 0.33 bbl water/bbl bitumen. Table 6 shows SAGDOX water make, assuming 20% residual bitumen in the steam swept zone and all injected steam is produced as water.
[0325] As a percent of steam injected, SAGDOX produces 20 to 260% excess water (excess to steam injected). No make-up water should be needed for SAGDOX steam generators.
4.9 Energy Injectivity
[0326] SAGD steam (energy) injection is usually controlled by a target pressure for a reservoir (i.e. we can increase steam injection rates until we hit a target pressure). This may work well if the reservoir has no “leaks” and we can increase pressures beyond the original native reservoir pressures. But, if we have a “leaky” reservoir or even if we have a contained chamber, our injection rates may be limited by hydraulic effects in our production well. The bitumen and water flow in the horizontal production well cannot create pressure drops that cause the steam/water interface to tilt and flood the toe of the steam injector or to allow gas/steam to enter near the heel of the production well ( FIG. 13 ). This can create a fundamental limit on energy injectivity (steam) for SAGD. Depending on actual well geometry and reservoir characteristics, this limit may supersede our pressure target limit.
[0327] SAGDOX can have the same behavior. The process still produces a bitumen and water mix in the lower horizontal well. But, the limits on energy injection are changed because a significant part of the energy injected is due to oxygen, which produces little water compared to steam. Also, if we have separate wells to remove produced gases (e.g. FIG. 3 ), we can control pressure by produced gas removal rates. So, if our energy injectivity is limited by fluid flows in the production well, Table 10 shows potential bitumen productivity increases, assuming fluid flow rate in the production well is constant. Extra bitumen productivity potential varies from 21 to 148% for our preferred oxygen concentration range (5 to 50% (v/v)). Our preferred case (SAGDOX (35)) can more than double bitumen production.
4.10 Pattern Extensions
[0328] As previously discussed steam (energy) injectivity for SAGD can be limited by one of two factors—the pressure in the reservoir or the hydraulic limits of the production well. If the pressure drop in the production well is the limiting factor, and if we convert SAGD to SAGDOX we can increase energy injectivity because per unit energy injected SAGDOX produces less water and less fluid in the production well than does SAGD.
[0329] If reservoir pressure is the limiting factor we cannot increase energy injectivity per unit length of our horizontal producer, but we can certainly increase the length of the producer without hitting the hydraulic limits and we can also thus increase bitumen production and increase reserves (by increasing the pattern size).
[0330] The above is a balancing act. SAGD operators have settled on a 5 m well spacing which for normal pipe sizes sets a hydraulic limit on well length at about 1000 m for bitumen production rates of about 1000 bbls/day. A conversion to SAGDOX would lower water production and allow possible well extensions (or longer initial well lengths) for the same hydraulic limits. Table 7 shows the estimated produced volumes of bitumen and water for our SAGDOX cases. The following points are noteworthy:
(1) As the oxygen injection increases for the same bitumen production, produced fluid volumes drop from 100% for SAGD to 35% for SAGDOX (75). (2) Our preferred case SAGDOX (35) has 46% of the fluid volumes of SAGD. (3) The bitumen cut in produced fluids rises from 23% for SAGD to 57% for SAGDOX (75).
[0334] So, if we intend to operate SAGDOX and if pressure is our limit on injectivity, we can drill longer horizontal wells and achieve higher productivity and reserves. Table 10 shows the expected production volumes (water+bitumen), per unit bitumen production, for each of our SAGDOX cases compared to SAGD. There are 2 competing factors that will determine pressure drops in production wells:
(1) The production volume decreases as the oxygen content in steam increases, even including connate water production and water produced directly by combustion. Compared to SAGD produced water+bitumen volumes decrease by 18 to 60% as we progress from SAGDOX (5) to SAGDOX (50) mixtures. By itself, this can reduce pressure drops in the production well considerably and enable extended well lengths, if desired. Pressure drop is a strong function of volume throughput (much stronger than a linear relationship). (2) The oil cut increases in the production well as we progress to higher oxygen contents. For SAGD, the expected oil cut is 23%. For SAGDOX, the oil cut increases from 28% for SAGDOX (5) to 57% for SAGDOX (50) (Table 10). For water-continuous emulsions (oil-in-water emulsions) this should not have a dramatic effect on pressure drops but it will increase bulk viscosity. Water-continuous emulsions can be stable for up to about 80% oil cut, so we can expect all SAGDOX cases to exhibit low viscosity flows.
Our expectation is that the first effect (1) will dominate and that we expect SAGDOX cases to have much lower pressure drops in the horizontal section of the production well than for SAGD for equal well lengths. Thus, for the same sized pipes, we can extend SAGD patterns significant distances if we convert to SAGDOX.
4.11 Multiple Pattern Options
[0338] If we apply SAGDOX to a mature SAGD project, neighboring patterns are in communication. We can take advantage of this by using a central steam injector for oxygen injection ( FIG. 15 ) and placing produced gas removal wells on the boundary of neighbor patterns. This reduces SAGDOX incremental wells to less than 1.0 per pattern.
[0339] Obviously for mature SAGD pattern that have established communication between pattern, other geometries are possible using the principles demonstrated in FIG. 3, 5, 6, 7, 8, 9, 10, 11, 12, 14, and 15 .
4.12 Distinguishing Features of SAGDOX
[0000]
(1) Applies to bitumen (not heavy oil).
(2) Obviates hydraulic limits of SAGD.
(3) Has a preferred range of O 2 concentrations in steam and O 2 .
(4) Injects steam and oxygen separately.
(5) Has a preferred range of 0 purity (95 to 99.9%).
(6) Separate well(s) to remove non-condensable gases.
(7) A procedure to start-up combustion component.
(8) A procedure to control/operate SAGDOX.
(9) A tapered strategy to inject oxygen.
(10) Specific proposed SAGDOX well geometries.
(11) A preferred way to produce steam and oxygen.
(12) A higher efficiency c/w SAGD.
(13) Reduced CO 2 emissions (with some CO 2 capture) c/w SAGD.
(14) Reduced water use c/w SAGD.
(15) Separate (or segregated) oxygen injector, with limited reservoir exposure (high flux rates).
(16) Can be added on to existing SAGD.
(17) Recognition of steam/oxygen synergies.
(18) Compared to SAGD, for the same energy injected, SAGDOX produces less fluid; this can allow higher energy injectivity rates or a lengthened pattern. The former will accelerate bitumen production; the latter will accelerate production and increase reserves.
5. Preferred Embodiments
5.1 Bitumen
[0358] The difference between bitumen and heavy oil is an important distinction for this invention. Bitumen is essentially immobile in a reservoir. Most bitumen reservoirs have no initial gas injectivity, so it is difficult (impossible) to initiate an EOR process with a combustion component without pre-steaming to heat and remove bitumen to create some gas injectivity. SAGD can accomplish this objective.
[0359] Although, in principle, SAGDOX can work on a heavy oil reservoir (where there is some initial gas injectivity) the preference is a bitumen reservoir, where SAGDOX is initiated using SAGD methods.
[0360] For the purposes of this document we will define “bitumen” as 10 API gravity and ≦1 million c.p. in situ viscosity. Heavy oil is then defined as between 10 and 20 API and 1 million c.p.
5.2 Separate Oxygen Injection
[0361] It has been suggested that EOR using a conventional SAGD geometry could be conducted by substituting an oxygen and steam mixture for steam (Yang (2009); Pfefferle (2008)). This is not a good idea for two reasons:
(1) Oxygen is different in its effectiveness compared to steam. Steam has a positive effect (adding heat) no matter how low the flux rate is or no matter how low the concentration. For oxygen to initiate and sustain the desired HTO combustion there is a minimum flux rate ( FIG. 25 ). This minimum rate is expected to depend on the properties of reservoir fluids, the properties of the reservoir, and the condition of the reservoir. If oxygen flux is too low either oxygen will break through, unused, to the produced gas removal well or the production well or remain in the reservoir, or the oxygen will initiate undesirable LTO reactions. If oxygen is mixed with steam and injected into a long horizontal well (500 to 1000 m) the oxygen flux is dispersed/diluted over a long distance. Even if the average oxygen flux is suitable to initiate and sustain HTO combustion, heterogeneities in the reservoir can cause local flux rates to be below the minimum needed. (2) Oxygen and steam mixtures are very corrosive particularly to carbon steel. The metallurgy of a conventional SAGD steam injector well could not withstand a switch to steam and oxygen mixtures without significant corrosion that could (quickly) compromise the well integrity. Corrosion has been cited as one of the issues for ISC projects that used enriched air or oxygen (Sarathi (1999)).
[0364] The SAGDOX preferred embodiment solution to these issues is to inject oxygen and steam in separate wells to minimize corrosion. Secondly the injector well (either a separate vertical well or the segregated portion of a horizontal well) should have a maximum perforated zone (or zone with slotted liners) of about 50 m so that oxygen flux rates can be maximized. Please refer to FIGS. 3A, 3B, 3C, and 3D in this regard.
5.3 Oxygen Concentration Ranges
[0365] Oxygen concentration in steam/oxygen injectant mix is a convenient way to quantify oxygen levels and to label SAGDOX processes (e.g. SAGDOX (35) is a process that has 35% oxygen in the mix). But, in reality we expect to inject oxygen and steam as separate gas streams without any real expectations of mixing in the reservoir or in average or actual in situ gas concentration. Rather than controlling “concentrations”, in practice we would control to flow ratios of oxygen/steam (or the inverse). So SAGDOX (35) would be a SAGDOX process where the flow ratio of oxygen/steam was 0.5385 (v/v).
[0366] Our preferred range for SAGDOX has minimum and maximum oxygen/steam ratios, with the following rationale:
(1) Our minimum oxygen/steam ratio is 0.05 (v/v) (oxygen concentration of about 5%). Below this we start getting increasing problems as follows:
i. HTO combustion starts to become unstable. It becomes more difficult to attain minimum oxygen flux rates to sustain HTO, particularly for a mature SAGDOX process where the combustion front is far away from the injector. ii. It also becomes difficult to vaporize and mobilize all connate water.
(2) Our maximum oxygen/steam ratio is 1.00 (v/v) (oxygen concentration of 50.0%). Above this limit we start getting the following problems:
iii. The reflux rates in the reservoir to sustain steam inventories exceed 70% of the total steam (Table 2). This may be difficult to attain in practice. iv. The net bitumen (“coke”) fuel that is consumed by oxidation starts to exceed the residual fuel left behind in the SAGD steam-swept zone. So compared to SAGD, SAGDOX (50+) may have lower recoveries and reserves. v. Above this limit it becomes difficult (impossible) to produce steam and oxygen from an integrated ASU: Cogen plant.
[0374] So the preferred range for oxygen/steam ratios is 0.05 to 1.00 (v/v) corresponding to a concentration range of 5 to 50% (v/v) of oxygen in the mix. A separate economic study shows the preferred range of oxygen/steam ratios to be about 0.4 to 0.7 (v/v) or an average concentration of about 35% (v/v) oxygen in the mix. SAGDOX (35) is our preferred case.
5.4 Tapered Oxygen Strategy
[0375] Oxygen is more cost-effective than steam as a way to inject energy (heat) into a bitumen reservoir. Per unit heat delivered, all-in oxygen costs (including capital charges) are about one third the equivalent steam costs. So, at least ultimately, there is an economic incentive to maximize the oxygen concentration in our SAGDOX gas mixture. Also, as a SAGDOX process matures, the combustion front will move further away from the oxygen injector. In 3-D, the front will appear as an expanding sphere. To sustain oxygen flux rates at the sphere surface we may require increasing oxygen rates to sustain HTO reactions.
[0376] But, near the beginning, for safety reasons we may wish to minimize oxygen rates. Also, in the early SAGDOX operations, oxygen injection can produce back pressure (injectivity) constraints with a build-up of non-condensable combustion gases.
[0377] So, for at least a few reasons, there is a logical basis to conduct a SAGDOX process by starting at low oxygen concentrations (>5 (v/v) %) and ramping up concentrations as the project matures (<50 (v/v) %).
[0378] For operations that are expected to continue indefinitely (>a week) our oxygen levels should be within the specified (preferred) ranges. But, in the wind-down phase of operations (close to the economic limits), we can take advantage of the existing steam inventory in the reservoir, by shutting in steam injection and continuing oxygen injection until we reach the more-favorable economic limit when oxygen costs=bitumen revenues, per barrel of bitumen produced.
5.5 Oxygen Purity
[0379] A cryogenic air separation unit (ASU) can produce oxygen gas with a purity variation from about 95 to 99.9 (v/v) % oxygen concentration. The higher end (99.0-99.9%) purity produces chemical grade oxygen. The lower end of the range (95-97%) purity consumes about 25% less energy (electricity) per unit oxygen produced (Praxair, (2010)). The “contaminant” gas is primarily argon. Argon and oxygen have boiling points that are close, so cryogenic separation becomes difficult and costly. If argon and nitrogen in air remain unseparated, the resulting mixture is 95.7% “pure” oxygen (see Table 8).
[0380] For EOR purposes, argon is an inert gas that should have no impact on the process.
[0381] The range of oxygen purity is 95 to 99.5% (v/v) purity.
[0382] The preferred oxygen concentration is 95-97% purity (i.e. the least energy consumed in ASU operations).
5.6 Oxygen/Steam Production
[0383] Oxygen and steam for SAGDOX can be produced in separate steam generator (boiler) and ASU facilities. Steam generators (boilers) require fuel—usually natural gas—and ASU requires electricity to operate. As an alternate to separate production we can integrate steam generation and oxygen production. A cogen plant can produce steam and electricity, with steam used for SAGDOX steam and electricity used for ASU oxygen production. The net effect is to use natural gas to produce steam and oxygen in volumes needed for SAGDOX. The advantages of the integrated cogen: ASU plant are reduced cost, improved energy efficiency, improved reliability (compared to grid power purchase) and reduced surface footprints. FIG. 16A is a schematic representation of an integral ASU & COGEN for a SAGDOX process.
[0384] To analyze the applicability of the integrated system, we will assume the following:
(1) The cogen plant has 20% waste energy, 80% of the inlet natural gas is converted to either steam or electricity. (2) There is a 10% steam loss in distribution to the well-head. (3) We have two oxygen cases to span the design of ASU plants—99.5% pure oxygen, using 390 kWh (e)/tonne O 2 ; and 95 to 97% pure oxygen, using 292.5 kWh (e)/tonne O 2 . (4) Oxygen heat release in the reservoir is 480 BTU/SCF (Butler, (1991)). (5) Steam heat release (or net steam release) is 1000 BTU/lb.
[0390] Using these assumptions we can calculate the total gas demand to cogen (MMBTU/bbl bit.) and the fraction of cogen energy input that produces electricity (i.e. the efficiency of the gas turbine). FIG. 16 shows this plot, for the range of oxygen purity between about 95 to 99.5%.
[0391] If we consider that conventional gas turbine efficiency varies from about 20-45%, our associated SAGDOX gas oxygen concentrations range from about 20 to 50%. This range is almost independent of oxygen purity ( FIG. 16 ).
[0392] So, if we wish to reduce costs and maximize efficient by producing SAGDOX gas mixtures from an integrated cogen & ASU plant, our preferred SAGDOX gas mix is between 20 and 50% (v/v), oxygen in the steam/oxygen mixture.
[0393] Our preferred SAGDOX (35) fits in the middle of this range.
5.7 SAGDOX Operation
[0394] In order to start SAGDOX using one of the configurations shown in FIG. 3, 5, 6, 7, 8, 9, 10, 11, 12, 14 , or 15 , we need to meet the following criteria:
(1) When oxygen is first injected the injection point (well completion) is near to or inside a steam swept zone, so we can minimize temperatures at/near the well, consume bitumen that would otherwise not be produced in a steam-only process, and we have good gas injectivity. (2) The injection point needs to be preheated to about 200° C. so oxygen will spontaneously react with residual fuel (“auto ignition”). (3) We have separate control of oxygen and steam injection. (4) Start-up time between SAGD and SAGDOX is minimized. (5) Communication is established between all wells, or at least between one oxygen injector, one produced gas removal well and the horizontal well pair. Steam circulation or steam injection is used for SAGDOX vertical wells. (6) The oxygen flux rate is high enough to initiate and sustain HTO combustion in situ.
[0401] If we satisfy the above criteria we start up SAGDOX as follows:
1) Start oxygen and reduce steam to achieve a proscribed oxygen concentration target at the same energy rates as SAGD (see Table 1). 2) After a while, or as reservoir pressures approach a target pressure, partially open one (or more) produced gas (PG) removal wells to remove non-condensable combustion gases and to control P. 3) If we have split/multiple PG wells (i.e. FIGS. 3, 7, 9, 10, 11, 14, 15 ), we can adjust PG removal rates to improve/optimize O 2 conformance. 4) There should be no/little oxygen gas in PG removal well gas. If there is, the well should be choked back or shut in. 5) There should be no/little non-condensable gas (CO 2 , CO, O 2 . . . ) in the horizontal producer fluids. If there is, the production rate should be slowed and/or oxygen conformance adjusted and/or PG removal rates increased.
[0407] For steady-state SAGDOX operations we need to monitor the following:
(1) P, T, gas concentrations and steam content in PG removal wells. (2) P and rates of steam injection. (3) P and rates of oxygen injection (also oxygen purity). (4) T, water, bitumen, P, fluid rates and steam/gas concentrations in horizontal production wells.
[0412] The preferred steady-state operation strategy includes the following:
(1) Adjust steam and oxygen rates to meet energy injection and oxygen/steam targets. (2) Adjust PG removal well rates to control pattern pressures and to control/optimize oxygen conformance. (3) Adjust horizontal well production rates for steam-trap control, assuming that region around the well is steam-saturated at reservoir pressures (i.e. sub cool control).
[0416] These monitored measurements can be used to adjust operation targets and optimize sweep/conformance.
6. SAGDOX Uniqueness
[0000]
(1) There should be limits on the preferred oxygen concentration ranges for SAGDOX injection gases. On the low end (5% (v/v) oxygen) the stability of in situ combustion has not been widely studied nor reported. Nor has it been reported that due to steam “helping” (see (2)), the low end concentration is lower than oxygen diluted with the same amount of nitrogen. On the high end (50% (v/v) oxygen) the limits due to fuel availability as residual bitumen or production from an integrated ASU: cogen plants are not in the literature, nor are they obvious.
(2) The synergistic benefits of oxygen and steam are not well recognized. Oxygen helps steam by the following:
i. Surface steam demand is reduced directly by the energy delivered in oxygen. ii. Extra steam is created by oxygen heat via oxidation of hydrocarbons, vaporization of connate water and reflux of water/steam. iii. This improves overall energy efficiency (see 4.6). iv. Non-condensable combustion gases migrate to the top of the pay zone and insulate the ceiling to reduce heat losses. v. Non-condensable gases can increase lateral growth rates of the gas (steam) chamber). vi. Because SAGDOX mixes cost less than pure steam, for the same energy content, production can be extended beyond the SAGD economic limit and increase ultimate recovery. vii. If some CO 2 is retained in the reservoir, CO 2 emissions can be reduced compared to SAGD.
Steam can also help oxygen/combustion by the following:
i. Steam pre-heats the reservoir so oxygen will auto-ignite to start combustion. ii. Near the combustion zone, steam can add OH and H radicals to improve and stabilize combustion reactions (Similar to smokeless flare technology) (see Kerr (1975)). iii. Steam added (and created) is an efficient fluid for heat transfer to convey heat to the cold bitumen interface. This can improve EOR productivity. iv. Steam stimulates increased combustion completeness (more CO 2 , less CO). v. Steam favors HTO over LTO combustion. Low temperature oxidation (LTO) can produce acids that cause emulsions and treating problems. LTO also releases less heat per unit O 2 consumed than HTO.
(3) Oxygen gas is more effective than air. In air, oxygen is diluted by nitrogen that is not beneficial in the reservoir. Although compressed air may be less costly than oxygen gas, if the produced gas must be treated (e.g. incinerated) before venting, air costs, all-in, can easily exceed oxygen costs
(4) The well configurations for SAGDOX are unique.
(5) SAGDOX can have higher energy injectivity than SAGD.
(6) SAGDOX can result in longer horizontal wells than SAGD (i.e. bigger patterns).
(7) No one has proposed/contemplated an integrated ASU/Cogen plant to make SAGDOX gases.
(8) Others that have contemplated using steam and oxygen “mixtures” (Yang (2009), Pfefferle (2008)), but proposed schemes that would not work because:
i. No provision for produced gas removal wells (both). ii. No concern about corrosion if steam and oxygen mixtures are used (both). iii. No provision for specific oxygen concentration ranges similar to SAGDOX (both). iv. No combustion at chamber walls (Pfefferle (2008)). v. No control of oxidation temperatures by increasing oxygen concentration (Pfefferle (2008)). vi. No provision for concentrated, high flux oxygen injection (both). vii. No specificity to bitumen (both).
[0000]
TABLE 1
SAGDOX Injection Gases
SAGD
SAGDOX(5)
SAGDOX(9)
SAGDOX(35)
SAGDOX(50)
SAGDOX(75)
% (v/v) oxygen
0
5
9
35
50
75
% heat from O2
0
34.8
50.0
84.5
91.0
96.8
BTU/SCF mix
47.4
69.0
86.3
198.8
263.7
371.9
MSCF/MMBTU
21.1
14.5
11.6
5.0
3.8
2.7
MSCF
0.0
0.7
1.0
1.8
1.9
2.0
O 2 /MMBTU
MSCF
21.1
13.8
10.6
3.3
1.9
0.7
Steam/MMBTU
Where:
(1) Steam heat value = 1000 BTU/lb
(2) O 2 heat/combustion value = 480 BTU/SCF O 2
(3) SAGD = pure steam
[0000]
TABLE 2
SAGD Productivity/Gas Injection
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
Totals
SAGD
(5)
(9)
(35)
(50)
(75)
ETOR
1.180
1.210
1.230
1.387
1.475
1.623
(MMBTU/bbl)
(MSCF/bbl)
24.89
17.43
14.25
6.98
5.61
4.37
Steam Component
(% (v/v)of mix)
100
95
91
65
50
25
ETOR(steam)
1.180
0.789
0.615
0.215
0.133
0.052
(% total heat)
100
65.2
50.0
15.5
9.0
3.2
(MSCF/bbl)
24.89
16.55
12.97
4.54
2.81
1.10
Oxygen Component
(% (v/v) of mix)
0.0
5
9
35
50
75
ETOR (O 2 )
0.0
0.421
0.615
1.172
1.342
1.571
(% total heat)
0.0
34.8
50.0
84.5
91.0
96.8
(MSCF/bbl)
0.0
0.88
1.28
2.44
2.80
3.27
Where:
(1) SAGDOX (5) - 5% (v/v) O 2 in the steam and oxygen mix.
(2) ETOR (O 2 ) - reservoir heat due to O 2 combustion.
(3) 480 BTU/SCF O 2 ; 1000 BTU/lb steam.
(4) Entries are average performance based on SAGD simulation.
(5) Same productivity (SAGD) assumed for all.
(6) Total ETOR is prorated based on O 2 content in SAGDOX, between SAGD and 1.375 × SAGD for SAGDOX (75).
[0000]
TABLE 3
SAGDOX Energy Efficiency
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGD
(5)
(9)
(35)
(50)
(75)
(100)
ETOR (steam)
1.180
0.789
0.615
0.215
0.133
0.052
0
ETOR (O2)
0
0.421
0.615
1.172
1.342
1.571
1.770
Total ETOR
1.180
1.210
1.230
1.387
1.475
1.623
1.770
% Energy Efficiency
99.5% pure O 2
73.8
81.1
84.4
91.5
92.7
93.8
94.3
95-97% pure O 2
73.8
81.5
85.4
92.4
93.8
95.1
95.7
Where:
(1) ETOR taken from Table 2.
(2) Energy Efficiency defined in text.
(3) 99.5% pure O 2 uses 390 kWh/tonne O 2
(4) 95-97% pure O 2 uses 292.5 kWh/tonne
[0000]
TABLE 4
SAGDOX CO 2 Emissions
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGD
(5)
(9)
(35)
(50)
(75)
MMBTU/bbl)
ETOR(O 2 )
0
0.421
0.615
1.172
1.342
1.571
ETOR(steam)
1.180
0.789
0.615
0.215
0.133
0.052
Total ETOR
1.180
1.210
1.230
1.387
1.475
1.623
CO 2 Emissions
Boiler (SCF/bbl)
1573
1052
820
287
177
69
Incinerator
0
90
331
250
286
335
(SCF/bbl)
Combustion
0
816
1192
2272
2.601
3045
(SCF/bbl)
Direct CO 2
1573
1958
2143
2809
3064
3449
totals (SCF/bbl)
(tonnes/bbl)
0.0826
0.1029
0.1126
0.1476
0.1610
0.1812
Ind. Elect.
0
61
89
170
194
227
(SCF/bbl)
Dir. and Ind.
1573
2.019
2232
2979
3258
3676
Totals (SCF/bbl)
(tonnes/bbl)
0.0826
0.1061
0.1173
0.1565
0.172
0.1931
Where:
(1) ETOR from Table 2.
(2) Assumes all produced gas is incinerated with fuel use at 10% of gas volume and the fuel gas is vented (no sequestration/retention).
(3) Boiler CO 2 emissions = 1333 SCF/MMBTU (steam) in reservoir.
(4) Incinerator CO 2 = 213 SCF/MMBTU (O 2 ) in reservoir.
(5) Combustion CO 2 = 1938 SCF/MMBTU (O 2 ) in reservoir.
(6) Ind. Elec. CO 2 = 144.5 SCF/MBTU (O 2 ) in reservoir.
[0000]
TABLE 5
SAGDOX CO 2 Emissions with Sequestration
SCF
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
CO 2 /bbl
SAGD
(5)
(9)
(35)
(50)
(75)
Boiler Flue Gas
1573
1052
820
287
177
69
Pure CO 2
0
816
1192
2272
2601
3045
Vent (comb)
Incin. Fuel
0
90
131
250
286
335
Total direct CO 2
1573
1958
2143
2809
3064
3449
Total direct with
1573
1052
820
287
177
69
pure CO 2 capture
Elec.
0
61
89
170
194
227
Indirect CO 2
Total direct
1573
2019
2232
2979
3258
3676
and indirect CO 2
Total with
1573
1113
909
457
371
296
pure CO 2 capture
% of SAGD
100
70.8
57.8
29.1
23.6
18.8
Where:
(1) If pure CO 2 is captured and sequestered, no incineration fuel is needed.
(2) See Table 4 for other assumptions.
[0000]
TABLE 6
SAGDOX Water Make
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
(5)
(9)
(35)
(50)
(75)
Energy
(MMBTU/bbl)
ETOR(O 2 )
0.421
0.615
1.172
1.342
1.571
ETOR(steam)
0.789
0.615
0.215
0.133
0.052
ETOR Total
1.210
1.230
1.387
1.475
1.623
Produced Water
(bbls/bbl bit)
Connate Water
0.333
0.333
0.333
0.333
0.333
Combustion Water
0.015
0.022
0.041
0.047
0.055
Steam Condensate
2.254
1.757
0.614
0.380
0.149
Totals
2.602
2.112
0.988
0.760
0.537
% Extra Water
15.4
20.2
60.9
100.0
260.4
Where:
(1) % extra water = % excess c/w steam condensate.
(2) Steam at 1000 BTU/lb.
(3) No reflux.
(4) All connate water, associated with bitumen, is produced.
(5) All steam injected is produced as steam condensate.
(6) ETOR as per Table 2.
[0000]
TABLE 7
SAGDOX Produced Fluid Volumes
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGD
(5)
(9)
(35)
(50)
(75)
ETOR
1.180
1.210
1.230
1.387
1.475
1.623
ETOR(steam)
1.180
0.789
0.615
0.215
0.133
0.052
Fluid Produced (bbl)
Bitumen
1.000
1.000
1.000
1.000
1.000
1.000
Steam Condensate
3.371
2.254
1.757
0.614
0.380
0.149
Connate Water
0
0.33
0.33
0.33
0.33
0.33
Comb. Water
0
0.015
0.024
0.046
0.053
0.062
Tolal
4.371
3.602
3.111
1.990
1.763
1.541
% (v/v) Bit. In mix
22.9
27.8
32.1
50.3
56.7
64.9
% of SAGD vol.
100
82.4
71.2
45.5
40.3
35.3
Where:
(1) ETOR (MMBTU/bbl bit) as per Table 2.
(2) Assumes no net reflux, in steady state.
(3) All connate water is produced.
(4) All combustion water is produced.
(5) SAGD = 100% steam.
[0000]
TABLE 8
Air Composition
(Dry basis)
% (v/v)
N 2
78.084
O 2
20.946
CO 2
0.033
Ar
0.934
Others
0.003
Totals
100.000
Where:
(1) Source - ‘Handbook of Chemistry and Physics’ 58 th Ed., 1977-79.
(2) “Others” includes Ne, He, Kr, Xe, H 2 , CH 4 , N 2 O.
[0000]
TABLE 9
SAGDOX Steam Use (Inventory) in Reservoir
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGD
(5)
(9)
(35)
(50)
(75)
ETOR(O 2)
0
0.421
0.615
1.172
1.342
1.571
ETOR(steam)
1.180
0.789
0.615
0.215
0.133
0.052
Total ETOR
1.180
1.210
1.230
1.387
1.475
1.623
Wellhead Steam
3.371
2.254
1.757
0.614
0.380
0.149
(bbl/bblbit)
Reservoir
Steam(bbl/bbl)
Sand Face Steam
2.360
1.578
1.230
0.430
0.266
0.104
Connate Steam
0
0.330
0.330
0.330
0.330
0.330
Combustion
0
0.015
0.024
0.046
0.053
0.062
Steam
Reflux Steam
0
0.437
0.776
1.554
1.711
1.864
Totals
2.360
2.360
2.360
2.360
2.360
2.360
Reflux (%)
0
19
33
66
73
79
Where:
(1) ETOR as per Table 2.
(2) Sand face steam vapor = 0.7 × well head steam (reflects losses down hole).
(3) All connate water in steam-swept zone is vaporized to steam.
(4) Assuming 80% initial bitumen saturation and 20% residual bitumen.
(5) Combustion steam as per 4.3.
(6) Reflux steam = plug for same total steam use.
(7) Reflux % = % of total steam.
[0000]
TABLE 10
SAGDOX Potential Productivity (Energy Injection) Increases
At SAGD
SAGDOX
SAGDOX
SAGDOX
SAGDOX
SAGDOX
Rates (/bbl bit)
SAGD
(5)
(9)
(35)
(50)
(75)
ETOR
1.180
1.210
1.230
1.387
1.475
1.623
ETOR(steam)
1.180
0.789
0.615
0.215
0.133
0.052
Steam (bbls)
3.371
2.254
1.757
0.614
0.380
0.149
Connate
0
0.330
0.330
0.330
0.330
0.330
Water(bbls)
Comb. Water(bbls)
0
0.017
0.024
0.046
0.053
0.062
Total Water(bbls)
3.371
2.601
2.111
0.990
0.763
0.541
Prod. Well
4.371
3.601
3.111
1.990
1.763
1.541
Vol. (bbls)
At Const. Prod.
Well Rate
Bitumen(bbls)
1.000
1.214
1.405
2.196
2.479
2.836
% Prod. Increase
0
21.4
40.5
119.6
147.9
183.6
% Bit Cut
22.9
27.7
32.1
50.3
56.7
64.9
Where:
(1) Assumes all connate water and combustion water is condensed and produced in horizontal production well.
(2) ETOR taken from Table 2.
(3) Connate water and combustion water as per Table 7.
[0000]
TABLE 11
Steam Assisted Gravity Drainage (SAGD) Alberta Projects
Company
Project
Size (mbopd)
On Production
ConocoPhillips
Surmount
100
2006-2012
Total
Joslyn
45
2010
Devon
Jackfish
35
2008
Encana
Christina Lake
18
20008
Encana
Foster Creek
40-60
now
Husky
Sunrise
50-200
2008-
Husky
Tucker Lake
30
2006
JACOS
Hangingstone
10
now
MEG Energy
Christina Lake
25
2008
North American
Kai Kos Dehseh
10
2008
Petro Canada
MacKay River
30-74
now-2010
OPTI/Nexen
Long Lake
72
2007
Suncor
Firebag 1 & 2
70
now
(CHOA June 2007)
Total capacity above = 530-744 KBD
[0000]
TABLE 12
World Active ISC Projects (1999)
Country
No. of Projects
KB/D Production
(%)
USA
9
5.1
18
Canada
4
6.5
23
India
5
0.4
1
Romania
4
11.4
40
Others
6
5.3
18
Totals
28
28.7
100
(Sarathi (1999))
[0445] As many changes therefore may be made to the embodiments of the invention without departing from the scope thereof. It is considered that all matter contained herein be considered illustrative of the invention and not in a limiting sense. | A process to recover hydrocarbons from a hydrocarbon reservoir, namely bitumen (API<10; in situ viscosity>100,000 c.p.), said process comprising;
establishing a horizontal production well in said reservoir; separately injecting an oxygen-containing gas and steam into the hydrocarbon reservoir continuously to cause heated hydrocarbons and water to drain, by gravity, to the horizontal production well, the ratio of oxygen/steam injectant gases being controlled in the range from 0.05 to 1.00 (v/v). removing non-condensable combustion gases from at least one separate vent-gas well, which is established in the reservoir to avoid undesirable pressures in the reservoir. | 4 |
FIELD OF THE INVENTION
This invention relates to a method of reducing the total carbon dioxide production and shift the balance of carbon dioxide from a reformer furnace flue gas to the high pressure syngas exit water gas shift reaction unit.
BACKGROUND
A process for making hydrogen with low to no CO2 production is disclosed in the present invention. It incorporates the concepts described in co-pending US patent application 2010-0037521, herein incorporated by reference, describes a process for making hydrogen by adjusting the conditions in the steam methane reformer (SMR) to produce more hydrogen and CO by converting more methane and subsequently converting more of the CO to Hydrogen in a lower temperature medium temperature shift or the combination of high temperature and low temperature shift reactors. This CO2 in the syngas is then removed by contacting with an amine wash and the hydrogen is purified in a pressure swing adsorption (PSA) unit—with the residue (tail gas) of the PSA being sent to the SMR furnace to provide the necessary fuel for the furnace. Supplemental fuel is provided typically by natural gas to provide the additional fuel needed to control the temperature of the SMR furnace. This process removes about 67% of the CO2 produced in the Hydrogen plant compared to a conventional steam methane reformer equipped with an amine contactor in which about 57% of the CO2 can be removed. The remaining CO2 is produced from remaining CO and Methane in the PSA tail gas and the supplemental natural gas fuel are combusted in the SMR furnace to CO2 and contribute the remaining CO2 which is not recovered and emitted in the Furnace flue gas. Co-pending US patent application 2010-0037521 further teaches that the CO2 recovery can be further increased to about 90% by increasing the SMR feed by 33% and reducing the hydrogen recovery in the PSA such that enough more hydrogen is passed to the tail gas and subsequently to the SMR furnace and no supplemental natural gas is supplied to the SMR Furnace.
Co-pending, as-yet unpublished patent application Ser. No. 12/970,041, herein incorporated by reference, teaches that the extent of pre-reforming can be increased by utilizing higher amounts of waste heat for pre-reforming. The reaction products from a first stage of pre-reforming is heated to a higher temperature by exchanging heat with flue gas or process gas and sent to a second adiabatic catalytic reactor in which the endothermic reforming reactions drop the temperature. The process can be repeated through up to 4 or 5 pre-reformers in series and subsequently increasing the amount of pre-reforming from about 8-10% per a single bed pre-reformer to up to 20-25%. With higher degree of pre-reforming, the firing duty of the main reformer is reduced.
Referring to Co-pending US patent application 2010-0037521, the inventors teach that CO2 emissions from an SMR can be reduced by reducing the amount of CO2 produced by burning hydrocarbons in the SMR furnace. Co-pending, as-yet unpublished patent application Ser. No. 12/970,041 teaches that by increasing the extent of pre-reforming utilizing waste heat as the heat source, that the firing duty of the main reformer is reduced. For example by using three stages of pre-reforming instead of one stage of pre-reforming, the CO2 emissions from a conventional SMR can be reduced by 5-6%. By utilizing the increased pre-reforming concepts disclosed in Ser. No. 12/970,041 in addition to the increased CO2 capture taught in invention 2010-0037521, the CO2 removed can be increased from about 67% to about 90% without lowering the PSA H2 recovery as taught in 2010-0037521. Another benefit of the invention is that by using waste heat from the SMR furnace to do additional pre-reforming, steam production is reduced and when combined with CO2 removal by an amine contactor, there is no net export of steam from the SMR.
CO2 recovery utilizing the present invention can be further increased to 100%. This is achieved by taking the flue gas from SMR furnace through a dryer to remove water and compressing it. Typical specification for Nitrogen used for Enhanced Oil Recovery is >95% nitrogen. The resulting flue gas from the present invention will contain >95% Nitrogen+Argon, <3.1% CO2 and less than 1.9% Oxygen and would be an excellent gas to be used for enhanced oil recovery. By utilizing the flue gas for Enhanced Oil Recovery, no flue gas is emitted from the SMR and therefore no CO2 or NOx emissions.
A preferred gas for enhanced oil recovery would contain very low oxygen content. To produce a flue gas with low oxygen content, the flue gas from the SMR is combined with purified hydrogen from the PSA and contacted over a bed of catalyst to promote combustion of H2 with O2 to form water. The resulting flue gas stream is dried to remove excess water and compressed and used for enhanced oil recovery. The composition of the flue gas stream would be >97% N2+Argon, <3% CO2 and <0.1% O2, <0.1% H2.
The production of hydrogen by the steam reforming of hydrocarbons is well known. In the basic process, a hydrocarbon, or a mixture of hydrocarbons, is initially treated to remove, or convert and then remove, trace contaminants, such as sulfur and olefins, which would adversely affect the reformer and the down stream water gas shift unit catalyst. Natural gas containing predominantly methane is a preferred starting material since it has a higher proportion of hydrogen than other hydrocarbons. However, light hydrocarbons or refinery off gases containing hydrocarbons, or refinery streams such as LPG, naphtha hydrocarbons or others readily available light feeds might be utilized as well.
The pretreated hydrocarbon feed stream is typically at a pressure of about 200 to 400 psig, and combined with high pressure steam, which is at a higher than the feed stream pressure, before entering the reformer furnace. The amount of steam added is much in excess of the stoichiometric amount. The reformer itself conventionally contains tubes packed with catalyst through which the steam/hydrocarbon mixture passes. An elevated temperature, e.g. about 1580° F., or 860° C., is maintained to drive the endothermic reaction.
Prereforming of hydrocarbons upstream of the SMR or ATR is a well known process. It converts heavier hydrocarbons (ethane and heavier) to methane. It may also convert some of the methane to hydrogen, CO, and CO2, depending upon the chemical equilibrium under the given conditions.
Prereformer utilizes waste heat in the flue gas or process stream, which otherwise may be utilized in raising steam. Utilization of high level heat (at about 1600° F. to about 900° F.) is thermodynamically more efficient when used for prereforming than for raising steam with boiling temperature of about 400° F. to 600° F. Disposal of excess steam is a problem in many plants.
Typically the feed (hydrocarbon and steam mixture) to the prereformer is preheated in the range of 850° F. to 1000° F. before contacting with a catalytic bed in an adiabatic reactor. The reactants come to a chemical equilibrium. The extent of conversion of methane to H2/CO/CO2 is a function of the reaction temperature, higher temperature favoring the conversion.
The inlet temperature of the feed to prereformer is limited by its potential to crack hydrocarbons and deposit carbon on the catalyst and the preheat coils. Heavier the feedstock, lower is the potential cracking temperature. For example, the feed temperature for typical light natural gas is limited to about 1000° F., while feed temperature for naphtha feed is limited to 850° F. The amount of waste-heat utilization for prereforming depends on the preheat temperature of feed mixture. There is a need for a process that can utilize larger amounts of waste heat for prereforming.
The effluent from the reformer furnace is principally hydrogen, carbon monoxide, carbon dioxide, water vapor, and methane in proportion close to equilibrium amounts at the furnace temperature and pressure. The effluent is conventionally introduced into a one- or two-stage water gas shift reactor to form additional hydrogen and carbon dioxide. The shift reactor converts the carbon monoxide to carbon dioxide by reaction with water vapor, which generates additional Hydrogen. This reaction is endothermic. The combination of steam reformer and water gas shift converter is well known to those of ordinary skill in the art.
If CO2 capture from the high pressure syngas stream exiting the water gas shift unit is desired, the shift converter effluent, which comprises hydrogen, carbon dioxide and water with minor quantities of methane and carbon monoxide is introduced into a conventional absorption unit for carbon dioxide removal. Such a unit operates on the well-known amine wash or other solvent processes wherein carbon dioxide is removed from the effluent by dissolution in an absorbent solution, i.e. an amine solution or potassium carbonate solution, respectively. Conventionally, such units can remove up to 99 percent or higher of the carbon dioxide in the shift converter effluent.
The effluent from the carbon dioxide absorption unit is introduced into a pressure swing adsorption (PSA) unit. PSA is a well-known process for separating essentially pure hydrogen from the mixture of gases as a result of the difference in the degree of adsorption among them on a particulate adsorbent retained in a stationary bed.
Conventionally, the remainder of the PSA unit feed components, after recovery of pure hydrogen product, which comprises carbon monoxide, the hydrocarbon, i.e. methane, hydrogen and carbon dioxide, is returned to the steam reformer furnace and combusted to obtain energy for use therein
To practice CO2 emissions capture from such hydrogen plants, one must consider total emissions resulting from the plant, which includes CO2 recovery from reformer furnace flue gas as well.
SUMMARY
The present invention is a method of reducing the carbon dioxide balance from a reformer furnace flue gas to the high pressure syngas exit water gas shift reaction unit, comprising; providing a first gas mixture; heating said first stream mixture to a first temperature, then introducing said heated first gas mixture into at least one pre-reforming chamber, thereby producing a pre-reformed mixture; said heating being provided by indirect heat exchange with one or more of an SMR furnace flue gas or an SMR furnace syngas further heating said pre-reformed mixture in a primary reformer, thereby generating a second gas mixture comprising hydrogen, carbon monoxide, carbon dioxide, and a flue gas, wherein said primary reformer comprises tubes filled with catalyst; introducing said second gas mixture into at least one isothermal shift reactor, or a combination of high followed by a low temperature shift reactor, or a medium temperature shift reactor, thereby generating a third gas mixture; introducing said third gas mixture into a standard H2 PSA unit, wherein said third gas mixture is separated into a hydrogen enriched stream and a PSA tail gas stream; introducing said PSA tail gas stream into a CPU system, wherein said PSA tail gas stream is separated into a carbon dioxide enriched stream, a hydrogen rich stream, and a residual stream, and introducing said residual stream as fuel into the reformer furnace along with natural gas, a portion of the feed hydrocarbon stream, a portion of the hydrogen enriched stream, or any other external make-up fuel for the reformer furnace, wherein step b) is repeated twice, for a total of three pre-reforming steps, the temperature at the second pre-reformer is higher than at the first pre-reformer, and the temperature at the third pre-reformer is higher than at the second, where the pre-reforming chamber comprises at least three beds of catalyst, wherein an outlet gas from each pre-reformer is heated up in a coil in exchange with the SMR furnace flue gas or process syngas before going to a next pre-reformer reactor, and an outlet gas from the third pre-reformer or before entering the main reformer tubes.
BRIEF DESCRIPTION OF DRAWINGS
The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, and in which:
FIG. 1 illustrates the use of a CPU in accordance with one embodiment of the present invention.
FIGS. 2A-2F illustrate various permutations in accordance with various embodiments of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Illustrative embodiments of the invention are described below. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
Turning to FIG. 1 , which illustrates one embodiment of the present invention, a first stream comprising hydrocarbons 101 , steam 102 , and possibly PSA offgas stream 144 is heated to a first temperature in first heat exchanger 103 , by indirect heat exchange with hot gas stream 117 , thereby producing first pre-reformer inlet stream 104 . First pre-reformer inlet stream 104 is then introduced into first pre-reforming chamber 105 , thereby producing first pre-reformed stream 106 .
First pre-reformed stream 106 is heated to a second temperature in second heat exchanger 107 , by indirect heat exchange with hot gas stream 116 , thereby producing second pre-reformer inlet stream 108 . Second pre-reformer inlet stream 108 is then introduced into second pre-reforming chamber 109 , thereby producing second pre-reformed stream 110 .
Second pre-reformed stream 110 is heated to a third temperature in third heat exchanger 111 , by indirect heat exchange with hot gas stream 115 , thereby producing third pre-reformer inlet stream 112 . Third pre-reformer inlet stream 112 is then introduced into third pre-reforming chamber 113 , thereby producing third pre-reformed stream 114 . Third pre-reformed stream 114 may then be heated once again in a fourth heat exchanger (not shown) prior to usage downstream. Note in one embodiment, hot gas stream 117 , hot gas stream 116 , and hot gas stream 115 may come from different sources (not shown).
The second temperature may be greater than said first temperature. The third temperature may be greater than said second temperature. The indirect heat exchange may be with a flue gas from an SMR furnace. The indirect heat exchanger may be with one or more process streams. The indirect heat exchange may be with SMR furnace syngas.
The amount of steam mixed with hydrocarbons depends on the catalyst, and the type of hydrocarbon feedstock. The skilled artisan will be able to select the proper amount of steam for any application without undue experimentation.
Each pre-reforming chamber may be a stand alone reactor. At least two pre-reforming chambers may be contained in a single vessel. All three pre-reforming chambers may be contained in a single vessel. The three pre-reforming beds may be stacked in one vessel with internal heads. The first pre-reforming chamber may have a first space velocity, the second pre-reforming chamber may have a second space velocity, and the third pre-reforming chamber may have a third space velocity, where the first space velocity is lower than said second space velocity or said third space velocity.
The pre-reformer chambers may consist of a bank of tubes filled with catalyst which are heated in contact with SMR furnace flue gas or syngas.
Third pre-reformed stream 114 is introduced to a novel primary reformer 119 , wherein a syngas stream 130 comprising at least carbon dioxide and hydrogen is produced. Novel primary reformer 119 may be configured and operated as defined in co-pending US patent application 2010-0037521, herein incorporated by reference. Either at least a portion 152 of the reformer furnace flue gas stream 134 or a portion 151 of the syngas stream 130 may be directed to the pre-reformer, as hot gas stream 115 .
A portion of the syngas stream 130 may be sent to a waste heat recovery unit 120 to produce steam 121 . The exit of waste heat recovery, stream 131 is then introduced to a high temperature shift reactor followed by a low temperature shift reactor, or alternatively either an isothermal or a medium temperature shift reactor (symbolically represented by 122 ). This produces a carbon dioxide richer stream 132 . Carbon dioxide richer stream 132 is further cooled in waste heat recovery unit 123 to generate steam 124 , and a cooler syngas stream 133 .
The cooler syngas stream 133 is introduced into the PSA unit 127 wherein relatively pure hydrogen 128 is recovered, and residual stream 129 may be compressed in compressor 141 to produce compressed stream 150 , and introduced into a CO2 separation unit 147 (such as a CPU, i.e. cryogenic purification unit). CO2 separation unit 147 may be a CPU or a combination of CPU and membrane units. In the CO2 separation unit 147 , stream 150 is separated into a CO2 stream 148 and a hydrogen rich stream 142 which may be recycled to PSA 127 and a residual stream 149 . A portion 144 of residual stream 149 may be recycled upstream of reformer 119 . At least a portion 143 of residual stream may be used as fuel in steam reformer 119 .
A portion of reformer furnace flue gas stream 134 may be sent to waste heat recovery unit 135 , to produce steam 136 or preheat other process streams (not shown). The total carbon dioxide recovered by the amine wash may represent greater than 80% of the overall carbon dioxide generated by the SMR, preferably 90%. The total carbon dioxide recovered by the amine wash may represent greater than 85% of the overall carbon dioxide generated by the SMR, preferably 95%.
In one embodiment of the present invention, the catalyst in the first pre-reformer consists of conventional pre-reforming catalyst, and the catalyst in following pre-reformers of typical main catalyst bed reforming catalyst.
A portion of the heat for the reforming reaction may be provided by exchange with exit gas through the helical shaped tubes. The temperature of the exit gas from the top of the helical tubes may be between 1200 and 1300 degrees F.
As illustrated in FIGS. 2A-2F , the various pre-reformers may be provided heat by either a portion 152 of the reformer furnace flue gas stream 134 , or a portion 151 of the syngas stream 130 , in any appropriate combination, but portion 151 and portion 152 will typically be at different pressure and of different composition, so physically blending these two portions will ordinarily not occur.
The flue gas from the SMR furnace may be utilized for industrial purposes resulting in 100% recovery of the CO2 and no emission of nitrogen oxides from the SMR. The SMR furnace flue gas may be compressed and used for “Enhanced Oil Recovery (EOR).” The SMR Furnace Flue gas may be dried to remove water by passing through a bed of adsorbent. The
Nitrogen+Argon composition of the flue gas downstream of the drier may be greater than or equal to 95%. The SMR flue gas may be contacted with Hydrogen from the PSA and passed over a bed of catalyst to promote combustion of H2 with O2. The oxygen content of the flue gas downstream of the combustion zone may be less than 0.1 mol %. The SMR Furnace Flue gas may be dried to remove water by passing through a bed of adsorbent. The Nitrogen+Argon composition of the flue gas downstream of the drier may be greater than or equal to 97%, preferentially 99%.
Illustrative embodiments have been described above. While the method in the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings, and have been herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the method in the present application to the particular forms disclosed, but on the contrary, the method in the present application is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the method in the present application, as defined by the appended claims.
It will, of course, be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but, would nevertheless, be a routine undertaking for those of ordinary skill in the art, having the benefit of this disclosure. | The present invention is a method of reducing the carbon dioxide balance from a reformer furnace flue gas to the high pressure syngas exit water gas shift reaction unit. Introducing a heated gas mixture into at least one pre-reforming chamber. The heating being provided by indirect heat exchange with one or more of an SMR furnace flue gas or an SMR furnace syngas introducing the gas mixture into a standard H2 PSA unit, wherein the gas mixture is separated into a hydrogen enriched stream and a PSA tail gas stream; introducing the PSA tail gas stream into a CPU system, wherein the PSA tail gas stream is separated into a carbon dioxide enriched stream, a hydrogen rich stream, and a residual stream, and introducing the residual stream as fuel into the reformer furnace along with natural gas. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of Ser. No. 60/636,779, filed on Dec. 15, 2004, and is also based on provisional application Ser. No. 60/636,779, filed on Dec. 15, 2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
DESCRIPTION OF ATTACHED APPENDEX
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates generally to the field of sidewalks and pathways and patios and more specifically to interlocking paver/tile.
Current methods used to install concrete paver tiles are to place the tile onto the dirt surface of the yard, spacing them with a gage or visually spacing them. The voids created by the spacing are either filled with sand or dirt, allowing for easy removal and replacement. This method does not allow for a stable walking surface and fails to provide means to prevent pulling apart or separating and from sliding back and forth or from shifting side to side and from settling downward and rising upward from one paver tile to the next.
Another method used, is filling the void with grout or other bonding material. This method allows for a secure walking surface, but does not allow for easy removal or replacement and fails to provide the means to eliminate grout or bonding for easy installation and assembly. Other methods used, have connecting splines or locking mechanisms installed in a rigid placement in the voids between the tiles and the planer surface. This practice is noted in U.S. Pat. No. 6,761,008 to Chen and U.S. Pat. No. 6,763,643 to Martenson and U.S. Patent Application No. 2004/0228684.A1 to Lombardo. The connecting spline configurations, while connecting the tiles securely on a flat even surface, they fail to provide the means to install or assemble on uneven and unlevel surfaces and fail to provide the means to eliminate gluing or secured by screws or nails. This type of connection fails to provide the means to tilt up or down and could lead to a wide gaping void between tiles or a connection failure resulting in not only a broken and unsafe surface, but a poor appearance.
SUMMARY OF THE INVENTION
The primary object of the invention is to provide a means for the pavers to tilt up and down without separating or leaving a gap in between paver tiles.
Still yet another object of the invention is to provide a means to place or install or assemble on uneven and unlevel surfaces.
A further object of the invention is to provide a means to prevent paver tiles from pulling apart or separating, and from sliding back and forth, or from shifting side to side and from settling downward and rising upward from one paver tile to the next.
Yet another object of the invention is to provide a means to eliminate any type of grout or grouting between paver tiles.
Still yet another object of the invention is to provide a means to eliminate cementing, gluing or securing by screws or nailing the paver tiles.
A further object of the invention is to provide a means to place over existing surfaces.
Yet another object of the invention is to provide a means for a stable walking surface.
Another object of the invention is to provide a means to produce or manufacture out of light weight materials for easy lifting and handling.
Another object of the invention is to provide a means for a fast and simple and an easy way to assemble and install paver tiles.
Another object of the invention is to provide a means to produce or manufacture several different sizes and shapes and several different surface patterns to be able to create an infinite amount of artistic patterns.
Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
In accordance with a preferred embodiment of the invention, there is disclosed interlocking paver/tile comprising: a plastic spline with gripping teeth, a spline receiver slot or groove on all sides of paver tile, a protruding or extended upper edge or mating radii surrounding the entire perimeter of the paver and allows the pavers to tilt up and down without separating or leaving a gap in-between paver tiles, prevent paver tiles from pulling apart or separating, prevent paver tiles from sliding back and forth or from shifting side to side, prevent paver tiles from settling downward and rising upward from one paver tile to the next, eliminate any type of grout or grouting, cementing, gluing or securing by screws or nails and produced out of light weight materials.
DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
Drawing Figures:
FIG. 1 shows a perspective view of a square paver tile.
FIG. 2 shows a perspective view of the Interlocking Paver/Tiles laying upon a yard surface.
FIG. 3 shows a perspective view of the connecting spline.
FIG. 3A shows a perspective sectional view of the connecting spline.
FIG. 4 shows a perspective cut-away view of the paver tile showing the spline retaining slots and mating radii.
FIG. 4A shows a close-up sectional end view of a paver tile.
FIG. 5 shows a sectional view of two paver blocks joined together in the tilt down position.
FIG. 5A shows a sectional view of two paver tiles joined together in the tilt up position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
Description— FIG. 1
The following detailed description is directed to the presently contemplated mode of carrying out the invention. This description is not intended to be limitative, but to be made solely for the purpose of illustrating the general principles of the invention. The various features and advantages of the present invention may be more readily understood with reference to the following detailed description, taken in conjuncture with the accompanying drawings like numbers refer to the same features or part thereof.
The preferred embodiment of the Interlocking Paver/Tiles of the present invention is illustrated in FIG. 1 . A perspective view of the Paver Tile 2 comprised of a mixture of concrete containing light weight lava rock and light weight lava sand, which reduces the overall weight of the tile over standard rock and sand. This depiction shows the mating radii 30 A and 30 B. Each of the radii 30 A and 30 B has a mirror image opposite each other forming a perimeter around the upper edge of the paver tile 2 . There are spline receiver slots 32 A and 32 B arranged perpendicular to the paver tile vertical planer surfaces 34 A and 34 B. There is a mirror image of slots 32 A and 32 B in the opposite vertical planer surfaces 34 A and 34 B establishing a 360 degree perimeter of slots around the paver tile 2 . The paver tile 2 has a top planer surface 36 that can have a multitude of different surfaces and textures cast into it and a paver tile bottom planer 44 surface to mate to the underlying surface 6 . This creates a stable walking surface.
FIGS. 2 – 5 A—Additional Embodiments
FIG. 2 is a perspective, illustrative depiction of the Interlocking Paver/Tiles 8 , combining several different sizes of paver tiles 2 arranged to form a large walking surface. These Paver Tiles 2 can be manufactured in an infinite number of sizes and shapes in order to create an artistic pattern.
FIG. 3 is a perspective view of the paver tile spline 4 showing the 38 A and 38 B spline edge radii, as well as, the spline gripper teeth 40 . The spline gripper teeth 40 are arranged in numerous rows and staggered to accommodate severe angular displacement that might be encountered during installation. The spline gripper teeth 40 are homogeneous with the spline top and bottom planer surfaces 42 and 43 . The entire attaching spline is manufactured with a, but not limited to a polymer material. This is to allow the spline 4 to be flexible enough to afford some angular distortion without compromising the integrity between the paver tiles 2 .
FIG. 3A is a close-up perspective sectional view of paver tile spline 4 showing the 38 A and 38 B spline edge radii, as well as the spline gripper teeth 40 . As noted in FIG. 3A the gripper teeth 40 are shaped in such a manner so that the gripper teeth 40 allow the paver tile spline to be inserted into the spline receiver slots 32 A and 32 B with relative ease, but resist removal with a higher level of resistance. The spline edge radii 38 A and 38 B are designed so that the paver tile spline 4 can be inserted into the spline receiver slots 32 A and 32 B easily.
FIG. 4 is a perspective sectional view of the corner of the paver tile 2 . This view shows the relative placement of the paver tile mating radii 30 A and 30 B in relation to the paver tile top planer surface 36 . It also shows the relation of the spline receiver slots 32 A and 32 B with the paver tile top planer surface 36 .
FIG. 4A is a close-up cutaway end view of the paver tile 2 depicting the mating radius 30 A, the spline receiver slot 32 A and the paver tile vertical planer surface 34 A in relation to the paver tile bottom planer surface 44 .
FIG. 5 is a cut-away end view depicting two paver tiles 2 with the paver tile mating radii 30 A and 30 B in contact and the paver tile vertical planer surfaces 34 A and 34 B fully displaced from their parallel alignment. This causes the paver tile top planer surfaces 36 to angle up towards each other, thus allowing the paver tile bottom planer surfaces 44 to adjust to the unevenness that may be encountered in the attaching floor surface 6 .
FIG. 5A is a cut-away end view depicting two paver tiles 2 with the paver tile mating radii 30 A and 30 B in contact and with the paver tile vertical planer surfaces 34 A and 34 B fully displaced from their parallel alignment. This causes the paver tile top planer surfaces 36 to angle down towards each other, thus allowing the paver tile bottom planer surfaces 44 to adjust to the unevenness that may be encountered in the attaching floor surface 6 .
OPERATION OF INVENTION
The preferred embodiment of the Interlocking Paver/Tiles of the present invention is illustrated in FIG. 1 , a perspective view of the paver tile 2 comprised of a mixture of concrete containing light weight lava rock and light weight lava sand. The mixture reduces the overall weight of the tile over standard rock and sand. The depiction shows the mating radii 30 A and 30 B. Each of the radii 30 A and 30 B has a mirror image opposite each other forming a perimeter around the upper edge of the paver tile 2 . There are spline receiver slots 32 A and 32 B arranged perpendicular to the paver tile vertical planer surfaces 34 A and 34 B. The paver receiver slots 32 A and 32 B and their mirror images are designed to receive the attaching spline 4 , which is of a polymer type material that allows for angular displacement of the spline planer surfaces 42 A and 42 B. This displacement allows for the angular displacement between the paver tile top planer tile surfaces 36 from the paver tile top surface of another paver tile 2 . Inserting the attaching spline 4 is accomplished by driving the attaching spline 4 into the paver receiver slots 32 A or 32 B of an additional paver tile 2 and driving the paver tile 2 onto the attaching spline until seated against the corresponding paver tile mating radii 30 A of each paver tiles 2 . Continue this process until the floor surface 6 that is desired is complete. There is a mirror image of slots 32 A and 32 B in the opposite vertical planer surfaces 34 A and 34 B establishing a 360 degree perimeter of slots around the paver tile 2 . The paver tile 2 has a top planer surface 36 , that can have a multitude of different surfaces and textures cast into it, and a paver tile bottom planer surface 44 to mate to the floor surface 6 . FIG. 5 is a cut-away end view depicting two paver tiles 2 with the paver tile mating radii 30 A and 30 B in contact and the paver tile vertical planer surfaces 34 A and 34 B fully displaced from their parallel alignment. This causes the paver tile top planer surfaces 36 to angle up towards each other, allowing the paver tile bottom planer surfaces 44 to adjust to the unevenness that may be encountered in the attaching floor surface 6 . And consequently, FIG. 5A shows a cut-away end view depicting two paver tiles 2 with the paver tile mating radii 30 A and 30 B in contact and with the paver tile vertical planer surfaces 34 A and 34 B fully displaced from their parallel alignment. This causes the paver tile top planer surfaces 36 to angle down towards each other, allowing the paver tile bottom planer surfaces 44 to adjust to the unevenness that may be encountered in the attaching floor surface 6 .
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | Interlocking paver system for the use of constructing sidewalks, pathways and decks being formed from a light weight material for easy handling. Joined together by a plastic spline with gripping teeth, which when placed in spline receiver slots on sides of paver, which has a protruding upper edge that surrounds the entire perimeter allowing the pavers to tilt up or down, which allows the pavers to be placed on uneven or unlevel surfaces and prevents pavers from separating and from moving side to side, back and forth, and from settling downward and lifting upward which establishes a stable walking surface that is easy to install or assemble. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application 61/120,519 filed on Dec. 8, 2008, which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to image sensors for use in digital cameras and other types of image capture devices, and more particularly to shallow trench isolation regions in image sensors.
BACKGROUND
[0003] An electronic image sensor typically captures images using an array of pixels, with each pixel including a light-sensitive photodetector for converting incident light into photo-generated charges. Shallow trench isolation (STI) regions are typically fabricated between adjacent photodetectors or pixels to isolate the photodetectors and reduce crosstalk. FIG. 1 is a simplified cross-sectional view of a portion of a pixel in accordance with the prior art. Pixel 100 includes photodetector 102 and STI region 104 . In FIG. 1 , photodetector 102 is configured as a pinned photodiode formed by charge storage region 106 and pinning layer 108 . In general, a photodiode will collect charge generated in, or charge that makes it to, the boundary region 110 provided by the junction 112 between the p-doped charge storage region 106 and the n-doped region (e.g., well or substrate) 114 .
[0004] STI region 104 is fabricated by etching a trench into region 114 and filling the trench with an insulating material. Interface 116 between STI region 104 and region 114 is typically a source for dark current and point defects. To reduce dark current and point defects, interface 116 is conventionally passivated by implanting one or more n-type dopants into the side walls and bottom of the trench. For example, one prior art passivation technique performs two passivation implantation steps after the trench is filled with the insulating layer. The first step implants a dose of phosphorus (e.g., 3×10 12 atoms per square centimeter at 250 kilo-electron volts (keV)) into the side walls and bottom of the trench, and the second step implants at a relatively high energy (e.g., 400 keV) a dose of phosphorus (e.g., 1.5×10 13 atoms per square centimeter) into the side walls and bottom of the trench.
[0005] Unfortunately, the implanted phosphorus dopants of the isolation regions, which may or may not include STI region 104 , spread laterally out into region 114 and under photodetector 102 during implantation and subsequent processing of image sensor 100 . The lateral spreading of the dopants can adversely affect the collection volume of photodetector 102 . FIG. 2 is a two-dimensional cross-sectional view illustrating doping contours of a photodetector between two implanted isolation regions in accordance with the prior art. The isolation regions are typically disposed on either side of photodetector 102 in a cross-section coming out of the page of FIG. 1 . Contour lines 200 depict the spreading of dopants from the STI regions adjacent to charge storage region 106 . As can be seen, the dopants spread laterally from the isolation regions and merge under charge storage region 106 .
[0006] FIG. 3 is a graphical view of exemplary junction and depletion edges for charge storage region 106 in FIG. 1 . Junction 112 is formed between the edge of charge storage region 106 and region 114 . Depletion edge 300 represents the edge of depletion region 110 . The spreading of the dopants in the isolation regions reduce the size of charge storage region 106 and produce a shallow depletion region 110 . The reduced size of depletion region 110 also reduces the quantum efficiency of the image sensor at longer wavelengths.
SUMMARY
[0007] An image sensor includes an imaging area that includes a plurality of pixels, with each pixel including a photosensitive charge storage region formed in a substrate. One or more shallow trench isolation (STI) regions are also formed in the substrate. The STI regions can be formed between pixels, between groups of two or more pixels, or outside the imaging area to isolate the pixels from other electronic components in the image sensor. A passivation implantation region contiguously surrounds the side wall and bottom surfaces of each trench in the one or more STI regions. A portion of each passivation implantation region is laterally adjacent to a respective charge storage region and resides in an isolation gap disposed between the respective charge storage region and a respective trench isolation region and in between the photodetectors in the other direction.
[0008] The one or more STI regions are fabricated by depositing and patterning a photoresist layer on the image sensor to form openings where one or more trenches are to be formed. The trench or trenches are formed in the substrate and the image sensor is annealed. One or more dopants are then implanted at a low energy into the side wall and bottom surfaces of each trench to form a passivation implantation region that contiguously surrounds the side wall and bottom surfaces of each trench. In image sensors that include STI regions, the passivation implantation region is also created in between photodetectors. A liner layer of oxide can be formed over the side wall and bottom surfaces of each trench either prior to, or after, implanting the dopant or dopants at a low energy into the side wall and bottom surfaces of each trench. The photoresist layer is then removed and the trench or trenches filled with an insulating material. After the trenches are filled with an insulating material, another layer of photoresist can be deposited on the image sensor and patterned to cover the sites where the photodetectors will be formed. One or more dopants can then be implanted into the STI regions, isolation regions, or FET regions in the pixels.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0009] The present invention increases the depletion region of a photodetector, thereby improving the collection efficiency of the photodetector. Therefore, the present invention also increases the quantum efficiency of the pixel and reduces pixel-to-pixel crosstalk between adjacent pixels. And finally, the present invention passivates the STI interface to reduce dark current generation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the invention are better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other.
[0011] FIG. 1 is a simplified cross-sectional view of a portion of a pixel in accordance with the prior art;
[0012] FIG. 2 is a two-dimensional cross-sectional view illustrating doping contours of a photodetector between two implanted isolation regions in accordance with the prior art;
[0013] FIG. 3 is a graphical view of exemplary junction and depletion edges for charge storage region 110 in FIG. 1 ;
[0014] FIG. 4 is a simplified block diagram of an image capture device in an embodiment in accordance with the invention;
[0015] FIG. 5 is a simplified block diagram of image sensor 406 shown in FIG. 4 in an embodiment in accordance with the invention;
[0016] FIG. 6 is a cross-sectional view of a first pixel structure in an embodiment in accordance with the invention;
[0017] FIGS.7(A)-7(G) are cross-sectional views of a portion of a pixel that are used to illustrate a method for fabricating shallow trench isolation regions in an embodiment in accordance with the invention;
[0018] FIG. 8 is a two-dimensional cross-sectional view illustrating a doping contour of the first pixel structure shown in FIG. 6 ;
[0019] FIG. 9 is a graphical view of exemplary junction and depletion edges for charge storage region 802 in FIG. 8 ;
[0020] FIG. 10 is a one-dimensional doping profile of STI region 722 in FIG. 7 ;
[0021] FIG. 11 is a cross-sectional view of a second pixel structure in an embodiment in accordance with the invention; and
[0022] FIG. 12 is a two-dimensional cross-sectional view illustrating a doping contour of the second pixel structure shown in FIG. 11 .
DETAILED DESCRIPTION
[0023] Throughout the specification and claims the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” The term “connected” means either a direct electrical connection between the items connected or an indirect connection through one or more passive or active intermediary devices. The term “circuit” means either a single component or a multiplicity of components, either active or passive, that are connected together to provide a desired function. The term “signal” means at least one current, voltage, or data signal.
[0024] Additionally, directional terms such as “on”, “over”, “top”, “bottom”, are used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration only and is in no way limiting. When used in conjunction with layers of an image sensor wafer or corresponding image sensor, the directional terminology is intended to be construed broadly, and therefore should not be interpreted to preclude the presence of one or more intervening layers or other intervening image sensor features or elements. Thus, a given layer that is described herein as being formed on or formed over another layer may be separated from the latter layer by one or more additional layers.
[0025] And finally, the terms “wafer” and “substrate” are to be understood as a semiconductor-based material including, but not limited to, silicon, silicon-on-insulator (SOI) technology, doped and undoped semiconductors, epitaxial layers or well regions formed on a semiconductor substrate, and other semiconductor structures.
[0026] Referring to the drawings, like numbers indicate like parts throughout the views.
[0027] FIG. 4 is a simplified block diagram of an image capture device in an embodiment in accordance with the invention. Image capture device 400 is implemented as a digital camera in FIG. 4 . Those skilled in the art will recognize that a digital camera is only one example of an image capture device that can utilize an image sensor incorporating the present invention. Other types of image capture devices, such as, for example, cell phone cameras and digital video camcorders, can be used with the present invention.
[0028] In digital camera 400 , light 402 from a subject scene is input to an imaging stage 404 . Imaging stage 404 can include conventional elements such as a lens, a neutral density filter, an iris and a shutter. Light 402 is focused by imaging stage 404 to form an image on image sensor 406 . Image sensor 406 captures one or more images by converting the incident light into electrical signals. Digital camera 400 further includes processor 408 , memory 410 , display 412 , and one or more additional input/output (I/O) elements 414 . Although shown as separate elements in the embodiment of FIG. 4 , imaging stage 404 may be integrated with image sensor 406 , and possibly one or more additional elements of digital camera 400 , to form a compact camera module.
[0029] Processor 408 may be implemented, for example, as a microprocessor, a central processing unit (CPU), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or other processing device, or combinations of multiple such devices. Various elements of imaging stage 404 and image sensor 406 may be controlled by timing signals or other signals supplied from processor 408 .
[0030] Memory 410 may be configured as any type of memory, such as, for example, random access memory (RAM), read-only memory (ROM), Flash memory, disk-based memory, removable memory, or other types of storage elements, in any combination. A given image captured by image sensor 406 may be stored by processor 408 in memory 410 and presented on display 412 . Display 412 is typically an active matrix color liquid crystal display (LCD), although other types of displays may be used. The additional 110 elements 414 may include, for example, various on-screen controls, buttons or other user interfaces, network interfaces, or memory card interfaces.
[0031] It is to be appreciated that the digital camera shown in FIG. 4 may comprise additional or alternative elements of a type known to those skilled in the art. Elements not specifically shown or described herein may be selected from those known in the art. As noted previously, the present invention may be implemented in a wide variety of image capture devices. Also, certain aspects of the embodiments described herein may be implemented at least in part in the form of software executed by one or more processing elements of an image capture device. Such software can be implemented in a straightforward manner given the teachings provided herein, as will be appreciated by those skilled in the art.
[0032] Referring now to FIG. 5 , there is shown a simplified block diagram of image sensor 406 shown in FIG. 4 in an embodiment in accordance with the invention. Image sensor 406 typically includes an array of pixels 500 that form an imaging area 502 . Image sensor 406 further includes column decoder 504 , row decoder 506 , digital logic 508 , and analog or digital output circuits 510 . Image sensor 406 is implemented as a back or front-illuminated Complementary Metal Oxide Semiconductor (CMOS) image sensor in an embodiment in accordance with the invention. Thus, column decoder 504 , row decoder 506 , digital logic 508 , and analog or digital output circuits 510 are implemented as standard CMOS electronic circuits that are electrically connected to imaging area 502 .
[0033] Functionality associated with the sampling and readout of imaging area 502 and the processing of corresponding image data may be implemented at least in part in the form of software that is stored in memory 410 and executed by processor 408 (see FIG. 4 ). Portions of the sampling and readout circuitry may be arranged external to image sensor 406 , or formed integrally with imaging area 502 , for example, on a common integrated circuit with photodetectors and other elements of the imaging area. Those skilled in the art will recognize that other peripheral circuitry configurations or architectures can be implemented in other embodiments in accordance with the invention.
[0034] FIG. 6 is a cross-sectional view of a first pixel structure in an embodiment in accordance with the invention. Pixel 500 is implemented as a p-type metal-oxide-semiconductor (pMOS) pixel in the embodiment of FIG. 6 . Other embodiments in accordance with the invention can implement pixel 500 as an n-type metal-oxide-semiconductor (nMOS) pixel with appropriate reverse conductivity types as recognized by one skilled in the art.
[0035] Pixel 500 includes photodetector 602 that collects and stores charge that is generated in response to light striking photodetector 602 . Transfer gate 604 is used to transfer the integrated charge in photodetector 602 to charge-to-voltage converter 606 . Converter 606 converts the charge into a voltage signal. Source-follower transistor 608 buffers the voltage signal stored in charge-to-voltage converter 606 . Reset transistor 606 , 610 , 612 is used to reset charge-to-voltage converter 606 to a known potential prior to pixel readout. And power supply voltage (VSS) 614 is used to supply power to source follower transistor 608 and drain off signal charge from charge-to-voltage converter 606 during a reset operation.
[0036] Photodetector 602 is implemented as a pinned photodiode consisting of n+ pinning layer 616 and p-type charge storage region 618 formed within n-type well 620 . Well 620 is formed within p-type epitaxial layer 622 . Epitaxial layer 622 is disposed on p-type substrate 624 .
[0037] Shallow trench isolation (STI) regions 626 are formed between the pixels, or between groups of two or more pixels, to isolate the pixels or groups of pixels from one another. Interface 628 resides between STI region 626 and pinning layer 616 and well 620 in the embodiment shown in FIG. 6 . In another embodiment in accordance with the invention, where photodetector 602 is configured as an unpinned photodetector, interface 628 resides between STI region 626 and well 620 . And finally, in yet another embodiment in accordance with the invention, interface 628 is created between STI region 626 and epitaxial layer 622 or some other type of substrate.
[0038] Referring now to FIGS. 7(A)-7(G) , there are shown cross-sectional views of a portion of a pixel that are used to illustrate a method for fabricating shallow trench isolation regions in an embodiment in accordance with the invention. FIG. 7(A) shows the portion of the pixel after a number of initial CMOS fabrication steps have been completed. The pixel at this stage includes an insulating layer 700 formed over substrate 702 . Layer 704 is formed over insulating layer 700 . Insulating layer 700 and layer 704 are configured as layers of silicon dioxide and silicon nitride, respectively, in an embodiment in accordance with the invention.
[0039] A photoresist layer 706 is then deposited and patterned over the image sensor to form openings 708 where STI regions are to be formed (see FIG. 7(B) ). Box 710 represents a site where a photodetector will eventually be formed. Next, as shown in FIG. 7(C) , layers 704 and 700 are etched to match the pattern in photoresist 706 . Trenches 712 are then formed by etching the exposed substrate 702 in openings 708 (see FIG. 7(D) ). Trenches 712 are etched such that isolation gaps 714 (indicated by dashed circles) are created between trenches 712 and site 710 . Isolation gaps 714 are immediately adjacent trenches 712 and do not extend under the charge storage region of the yet to be formed photodetector. Next, photoresist 706 is removed, as shown in FIG. 7(E) . A liner layer 716 of oxide is then thermally grown on the side wall and bottom surfaces of trenches 712 (see FIG. 7(F) ) and an anneal process performed on the image sensor. The anneal process reduces any detrimental effects caused by etching epitaxial layer 702 to form trenches 712 and by the formation of the insulating oxide layer 716 . The anneal smoothes out the surfaces of the side walls and bottoms of trenches 712 , relieves stress, and reduces dangling bonds and surface states along the side walls and bottoms of trenches 712 .
[0040] A low energy passivation implantation at different angles (illustrated by the arrows 718 ) is then performed to implant dopants into the side wall and bottom surfaces of trenches 712 . Performing the low energy passivation implantation after the liner layer 716 is grown can minimize lateral spreading of the dopants. In one embodiment in accordance with the invention, a dose of arsenic (1.5×10 13 atoms per square centimeter) is implanted at 40 keV into the side wall and bottom surfaces of trenches 712 . This low-energy implantation forms passivation implantation regions 720 along the side walls of trenches 712 in isolation gaps 714 and along the bottoms of trenches 712 in substrate 702 .
[0041] Next, layer 704 and insulating layer 700 are removed, as shown in FIG. 7(G) . An insulating layer, such as a silicon dioxide layer, is deposited over the image sensor and selectively removed so that trenches 712 are filled with insulating material and form STI regions 722 . Although not shown in FIG. 7 , an oxide is typically grown before the next processes are performed.
[0042] Photoresist 724 is then deposited and patterned to cover site 710 where a photodetector will be subsequently formed, as well as other areas that will not be included in a second passivation implantation. The second passivation implantation is performed (illustrated by the arrows 726 ) to implant dopants around and into STI regions 722 . By way of example only, the second passivation implantation is performed in two steps in an embodiment in accordance with the invention, with the first step implanting a dose of arsenic (1.2×10 13 atoms per square centimeter) at 130 keV, and the second step implanting a dose of phosphorus (5×10 12 atoms per square centimeter) at 140 keV.
[0043] Photoresist 724 is then removed and production of the image sensor is now completed using traditional fabrication processes well known in the art. For example, the photodetectors will be formed by implanting dopants into substrate 702 . Since these fabrication processes are well known, the steps will not described in detail herein.
[0044] Although the embodiment of FIG. 7 is described as implanting particular doses of arsenic and phosphorus into the side wall and bottom surfaces of the trenches for a pMOS pixel, embodiments in accordance with the invention are not limited to these two particular dopants or doses. One or more different types of n-type dopants or different dosage amounts can be implanted into the side walls and bottom surfaces of the trenches in other embodiments in accordance with the invention. Alternatively, for an nMOS pixel, appropriate conductivity types are reversed as will be recognized by one skilled in the art. Thus, when the charge storage regions are doped with an n-type dopant, one or more p-type dopants can be implanted into the side wall and bottom surfaces of the trenches.
[0045] Moreover, other embodiments in accordance with the invention can include additional or alternative fabrication steps. And some of the fabrication steps shown in FIG. 7 can be performed in a different order. For example, the low-energy implantation can be performed before the liner layer 716 of oxide is formed on the side walls and bottoms of the trenches 712 .
[0046] FIG. 8 is a two-dimensional cross-sectional view illustrating a doping contour of the first pixel structure shown in FIG. 6 . Contour lines 800 depict lines of constant doping density from passivation implantation regions 720 . As can be seen, the dopants surround the sides of STI regions 722 and isolation gaps 714 . The dopants also spread into substrate 702 or surround the bottom of STI regions 722 . The dopants do not, however, significantly diffuse under charge storage region 802 . This minimal encroachment by the dopants into the depletion region of a photodetector opens up the depletion region and increases collection volume of the photodetector.
[0047] FIG. 9 is a graphical view of exemplary junction and depletion edges for charge storage region 802 in FIG. 8 . Junction 900 is formed between the edge of charge storage region 802 and a substrate. Depletion edge 902 represents the boundary of depletion region 904 . Both charge storage region 802 and depletion region 904 are larger in size than the prior art charge storage region 106 and depletion region 300 shown in FIG. 3 . As discussed earlier, the larger charge storage region 802 and depletion region 904 increase the collection volume of the photodetector.
[0048] Moreover, the interface between STI regions 722 and substrate 702 are passivated effectively, thereby reducing dark current. FIG. 10 is a one-dimensional doping density plot of STI region 722 in FIG. 7 . The plot is down through the center of the trench. As can be seen, the doping density at the bottom of STI regions 722 is approximately 2×10 18 cm −3 to 3×10 18 cm −3 (see point 1000 ). The doping concentration along the trench side wall is at this same order of magnitude.
[0049] Referring now to FIG. 11 , there is shown a cross-sectional view of a second pixel structure in an embodiment in accordance with the invention. Pixel 1100 includes transfer gate 604 , charge-to-voltage converter 606 , source follower transistor 608 , reset transistor 606 , 610 , 612 , pinning layer 616 , epitaxial layer 622 , substrate 624 , and STI region 626 described in conjunction with FIG. 6 . Buried n-type layer 1102 is formed within a portion of epitaxial layer 622 . N-type wells 1104 , 1106 are formed within another portion of epitaxial layer 622 . Well 1106 is contained within pixel 1100 and is disposed laterally adjacent to and abutting photodetector 1108 .
[0050] Region 1110 of epitaxial layer 622 is positioned between buried layer 1102 , photodetector 1108 , and wells 1104 , 1106 . The doping of the region 1110 is substantially the same as the doping of epitaxial layer 622 in an embodiment in accordance with the invention. Region 1110 effectively produces an “extension” of p-type charge storage region 1112 in photodetector 1108 . This results in a deeper depletion depth and a deeper junction depth for photodetector 1108 .
[0051] Additionally, isolation region 626 , when fabricated pursuant to the method shown in FIG. 7 , has an interface 628 that is effectively passivated. There is minimal encroachment by the passivation implantation region dopants into the depletion region of photodetector 1108 . In an alternate embodiment in accordance with the invention, wells 1104 , 1106 abut and make direct contact with buried layer 1102 . U.S. patent application Ser. No. 12/054,505, filed on Mar. 25, 2008 and entitled “A Pixel Structure With A Photodetector Having An Extended Depletion Depth,” incorporated by reference herein, describes in more detail the pixel structure of FIG.11 and an alternate pixel structure where wells 1104 , 1106 abut buried well 1102 .
[0052] FIG. 12 is a two-dimensional cross-sectional view illustrating a doping contour of the alternate second pixel structure described in conjunction with FIG. 11 . In this embodiment, wells 1104 , 1106 abut and make direct contact with buried layer 1102 . Contour lines 1200 depict the spreading of dopants from the passivation implantation region surrounding STI region 626 . As can be seen, the dopants surround the sides and bottom of STI region 626 . The dopants do not, however, significantly spread under charge storage region 1112 . Additionally, region 1110 (not shown in FIG. 12 ) effectively produces an extension 1202 of charge storage region 1112 in photodetector 1108 ( 1108 and 1112 not shown in FIG. 12 ). This extension results in a deeper depletion depth and a deeper junction depth for photodetector 1108 .
[0053] The invention has been described with reference to particular embodiments in accordance with the invention. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention. By way of examples only, an image sensor can be implemented as a CMOS image sensor or a charge-coupled device (CCD) image sensor. A bulk wafer overlying the substrate can be used instead of substrate 624 and epitaxial layer 622 . Photodetector 602 ( FIG. 6 ) or photodetector 1108 ( FIG. 11 ) can be implemented using alternate structures or conductivity types in other embodiments in accordance with the invention. Photodetectors 602 , 1108 can be implemented as an unpinned p-type diode formed in an n-well in a p-type substrate in another embodiment in accordance with the invention. In other embodiments in accordance with the invention, photodetector 602 , 1108 can include a pinned or unpinned n-type diode formed within a p-well in an n-type substrate. And finally, although a simple non-shared pixel structure is shown in FIG. 6 and FIG. 11 , a shared architecture is used in another embodiment in accordance with the invention. One example of a shared architecture is disclosed in U.S. Pat. No. 6,107,655.
[0054] Additionally, even though specific embodiments of the invention have been described herein, it should be noted that the application is not limited to these embodiments. In particular, any features described with respect to one embodiment may also be used in other embodiments, where compatible. And the features of the different embodiments may be exchanged, where compatible.
PARTS LIST
[0000]
100 pixel
102 photodetector
104 shallow trench isolation (STI) region
106 charge storage region
108 pinning layer
110 depletion region
112 junction
114 substrate
116 interface
200 contour lines
300 junction of charge storage region
302 edge of depletion region
400 image capture device
402 light
404 imaging stage
406 image sensor
408 processor
410 memory
412 display
414 other input/output devices
500 pixel
502 imaging area
504 column decoder
506 row decoder
508 digital logic
510 analog or digital output circuits
602 photodetector
604 transfer gate
606 charge-to-voltage converter
608 source follower transistor
610 gate of reset transistor
612 source/drain of reset transistor
614 power supply voltage
616 pinning layer
618 charge storage region
620 well
622 epitaxial layer
624 substrate
626 STI region
628 interface
700 insulating layer
702 substrate
704 layer
706 photoresist
708 openings
710 site of to be formed photodetector
712 trench
714 isolation gap
716 liner layer
718 arrows representing dopant implantation
720 passivation implantation regions
722 STI region
724 photoresist
726 arrows representing dopant implantation
800 contour lines
802 charge storage region
900 junction of charge storage region
902 edge of depletion region
904 depletion region
1000 dopant density at interface
1100 pixel
1102 buried layer
1104 well
1106 well
1108 photodetector
1110 region
1112 charge storage region
1200 contour lines
1202 extension of charge storage region | An image sensor includes an imaging area that includes a plurality of pixels, with each pixel including a photosensitive charge storage region formed in a substrate. A passivation implantation region contiguously surrounds the side wall and bottom surfaces of each trench in the one or more trench isolation regions. A portion of each passivation implantation region is laterally adjacent to a respective charge storage region and resides only in an isolation gap disposed between the respective charge storage region and a respective trench isolation region and does not substantially reside under the charge storage region. Each passivation implantation region is formed by implanting one or more dopants at a low energy into the side wall and bottom surfaces of each trench after annealing the image sensor and prior to filling the trenches with an insulating material. | 7 |
[0001] The present invention relates to a method of positioning turbine stage arrays, particularly for aircraft engines.
BACKGROUND OF THE INVENTION
[0002] As is known, an aircraft engine comprises a multistage compressor; a combustor; and an axial multistage expansion turbine, each stage of which comprises a stator fixed angularly about an axis of the engine, and a rotor rotating about the axis.
[0003] As known from European Patent EPO756667, to maximize the aerodynamic efficiency of the turbine, the stators all have the same number of blades and, considering a first and a second stator forming part of two consecutive stages in the axial flow direction of the gas in the engine, the angular position of the second stator about the engine axis is set with respect to that of the first stator as a function of the paths of the wakes generated by the first stator and flowing into the rotor interposed between the first and second stator.
[0004] More specifically, the second stator is positioned to roughly align the leading edges of the second-stator blades with the wakes from the rotor.
[0005] The above known positioning method is not always satisfactory and at times may either have no effect at all or even the opposite effect, i.e. tests show a reduction as opposed to an increase in the aerodynamic efficiency of the turbine as compared with that obtainable with the stator set to any angular position.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a method of positioning turbine stage arrays, particularly for aircraft engines, designed to provide a straightforward systematic solution to the above problem.
[0007] According to the present invention, there is provided a method of positioning arrays of stages of a turbine, particularly for aircraft engines, the turbine having an axis and comprising a first, a second and a third array arranged consecutively and comprising a number of first, second and third blades respectively; said first and said third array having a relative velocity about said axis with respect to said second array; the method comprising the step of determining the paths of wakes moving inside gaps defined by said number of second blades and towards said third array, and the step of regulating the position of said third array with respect to said first array as a function of said wakes; and being characterized by also comprising the steps of distinguishing, for each said wake, a first and at least one second zone differing from each other, and of selecting one of said first and said second zone; the position of said third array being regulated by aligning the leading edges of said number of third blades with the paths of the selected wake zones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention will now be described with reference to the accompanying drawings, in which FIGS. 1 to 4 show, by way of example, a sequence of four consecutive instants in the operation of a turbine illustrated in the form of plan views of a circumferential section and regulated according to a preferred non-limiting embodiment of the method according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Number 1 in the accompanying drawings indicates as a whole a gas expansion turbine having an axis 2 and forming part, in particular, of an aircraft engine comprising a multistage compressor (not shown) and a combustor (not shown), both located upstream from turbine 1 and successively in the axial gas flow direction (indicated by arrow A) through the engine. Turbine 1 comprises a number of stages, two of which are shown partly and indicated 4 and 5 in the accompanying drawings.
[0010] The accompanying drawings show plan views of a section of turbine 1 along a cylindrical surface at a given radial distance from axis 2 , and show three successive arrays 9 , 10 , 11 of respective blades 12 , 13 , 14 forming part of a stator 6 , a rotor 7 and a stator 8 (shown partly) respectively. Stator 6 and rotor 7 form part of stage 4 ; stator 8 forms part of stage 5 ; and arrays 9 , 11 have the same number of blades.
[0011] Blades 12 , 13 , 14 define respective numbers of interblade gaps 15 , 16 , 17 through which flows the stream of expanding gas flowing axially through turbine 1 in the direction of arrow A. As is known, each blade 12 , 13 , 14 has a wing profile and comprises a front or leading edge 21 and a tapered rear or trailing edge 23 .
[0012] Gas flow in turbomachinery is nonstationary and affected strongly by the interaction of pressure waves, shock waves and stator and rotor wakes. The accompanying drawings relate to four respective consecutive instants, and show, by isentropic lines, the wake patterns and paths in the gas flow in gaps 15 , 16 , 17 . Here and hereinafter, the term “wake” is intended to mean any flow portion characterized by a high level of entropy with respect to the mean level in the flow, and which is generated by the trailing edge 23 of any blade of turbine 1 .
[0013] The trailing edge 23 of each blade 12 generates a respective wake 25 . When the leading edges 21 of blades 13 encounter and “cut” wakes 25 as rotor 7 rotates, each wake 25 interacts with the boundary layer on the back, i.e. suction face, 26 of each blade 13 , and progresses in the form of a wake 27 . As array 10 rotates, each wake 27 travels along back 26 and flows off trailing edge 23 of relative blade 13 towards array 11 while, at the same time, each blade 13 encounters and “cuts” the next wake 25 .
[0014] As it proceeds along gap 16 , each wake 27 interacts with the flow field of rotor 7 and is broken up into a number of successive zones which are particularly evident at the outlet of gap 16 and have different thermodynamic and fluid-dynamic properties.
[0015] In the example shown, each wake 27 comprises two zones 31 and 32 spaced apart and of which zone 31 is the first to interact with array 11 and has a lower entropy value than zone 32 .
[0016] Turbine 1 is regulated by positioning array 11 angularly about axis 2 and with respect to the position of array 9 as a function of wakes 27 , to obtain a relatively high degree of aerodynamic efficiency of turbine 1 .
[0017] The method of regulating or indexing turbine 1 comprises determining the path of wakes 27 , and distinguishing, in each wake 27 , zones 31 , 32 having different thermodynamic and fluid-dynamic properties. Once zones 31 , 32 are identified, their paths are determined, one of zones 31 , 32 is selected, and the angular position of array 11 (“indexed array”) is regulated to align each leading edge 21 in array 11 with the path of the selected wake zone, and to allow the nonselected wake zone to flow into relative gap 17 .
[0018] The different zones 31 , 32 in wake 27 , the paths of wakes 25 , 27 and zones 31 , 32 , the properties of the various points in wakes 27 and the efficiency of turbine 1 are all determined theoretically using a mathematical model describing and simulating the gas flows and the motion of turbine 1 .
[0019] The mathematical model is formed by selecting a mathematical algorithm as a function of the type of turbine 1 and, in particular, of the type of flow occurring at the boundary layer of blades of turbine 1 . Known mathematical algorithms can be classified into two groups, depending on whether the algorithm describes boundary layer flow in a completely turbulent flow condition typical of so-called “high-pressure” turbines, or in a laminar-turbulent flow transition condition typical of so-called “low-pressure” turbines. By way of example, of the algorithms in the first group describing the boundary layer, one of the known algorithms listed in the following bibliographical references, and preferably the so-called “mixing length” method, may be selected:
[0020] 1) Arnone A., Liou M. -S. and Povinelli L. A., 1991, “Multigrid Calculation of Three-Dimensional Viscous Cascade Flows”, AIAA 9th Applied Aerodynamics Conference, Baltimore, Md., September, 1991, AIAA-91-3238, NASA TM-105257, ICOMP-91-18, Journal of Propulsion and Power, Vol. 9, No. 4, July-August 1993, p. 605-614.
[0021] 2) Arnone A., Liou M. -S. and Povinelli L. A., 1992, “Navier-Stokes Solution of Transonic Cascade Flow Using Non-periodic C-Type Grids”, Journal of Propulsion and Power, Vol. 8, No. 2, March-April 1992, p. 410-417.
[0022] 3) Arnone A., Liou M. -S. and Povinelli L. A., 1995, “Integration of Navier-Stokes Equations Using Dual Time Stepping and a Multigrid Method”, AIAA Journal, June 1995, Vol. 33, No. 6, p. 985-990.
[0023] 4) Arnone A., Pacciani R. and Sestini A., 1995, “Multigrid Computations of Unsteady Rotor-Stator Interaction Using the Navier-Stokes Equations”, ASME Winter Annual Meeting, Unsteady Flows in Aeropropulsion, AD-Vol. 40, p. 87-96, ASME Journal of Fluids Engineering, December 1995, Vol. 117, p. 647-652.
[0024] Again by way of example, of the algorithms in the second group, the one derived from the studies of AbuGhannam Shaw and Mayle and described in the following bibliographic reference may preferably be selected:
[0025] 5) Arnone A., Marconcini M., Pacciani R. and Spano E., 1999, “Numerical Prediction of Wake Induced Transition in a Low Pressure Turbine”, AIAA paper 99-IS-058, XIV ISABE Symposium, Sep. 5-10, 1999, Florence, Italy.
[0026] Once the mathematical algorithm is selected as a function of the type of flow in the boundary layer of turbine 1 , the mathematical model is calibrated as a function of the boundary conditions, i.e. by entering the parameters defining, on the one hand, the geometric characteristics of the turbine 1 for indexing, and, on the other, the thermodynamic characteristics and turbulence conditions of the gases upstream from turbine 1 .
[0027] The resulting mathematical model is then analyzed using a computation method or code, in particular a version of a so-called “TRAF3D” code capable of solving Reynolds-averaged Navier-Stokes equations, using computation acceleration techniques to solve stationary and nonstationary quasi-three-dimensional and three-dimensional flow fields.
[0028] The above computation method is described in the above bibliographic references.
[0029] Once the mathematical model is analyzed and computed, the wake zone with which to align each leading edge 21 of array 11 is selected as a function of the thermodynamic and fluid-dynamic properties of zones 31 , 32 , and preferably by comparing the entropy values determined theoretically in zones 31 , 32 and at various points in wakes 27 in general.
[0030] With reference to the accompanying drawings, array 11 is positioned to align the leading edges 21 of blades 14 with the paths of the higher-entropy wake zones, i.e. zones 32 , so that zones 32 strike leading edges 21 of blades 14 and zones 31 flow into gaps 17 .
[0031] Alternatively, the wake zone by which to index array 11 is selected by determining, preferably theoretically, which zone 31 , 32 gives the higher efficiency. Array 11 is positioned by aligning leading edges 21 first with one and then with the other of zones 31 , 32 ; the efficiency of turbine 1 is determined for each position; and the higher-efficiency wake zone and position are selected.
[0032] More generally speaking, array 11 may be set to a number of trial-and-error angular positions, and the highest-efficiency position selected. The same also applies to fine-positioning array 11 .
[0033] By indexing array 11 with respect to the paths of zones 32 , the aerodynamic efficiency of turbine 1 has been found, both experimentally and theoretically, to assume the highest value obtainable by setting stator 8 to a number of generic positions about axis 2 and with respect to stator 6 .
[0034] In the event (not shown) turbine 1 is set to align leading edges 21 of blades 14 with the paths of zones 31 , the aerodynamic efficiency of turbine 1 has been found, both experimentally and theoretically, to assume the lowest possible value, despite array 11 being indexed on the basis of generic wakes 27 .
[0035] Testing provides for confirming the theoretical findings and, in particular, the fact that the mathematical model used represents the actual operating conditions.
[0036] The positioning method described therefore provides for accurately adjusting the relative position of stages 4 , 5 of turbine 1 by accurately defining, unlike known methods, the angular position of array 11 with respect to array 9 best suited to achieve the highest efficiency of turbine 1 .
[0037] The reason for this lies in necessarily distinguishing the various contributions or zones into which each wake 27 is broken prior to interacting with the indexed array 11 , and selecting the right wake zone with which to align the leading edges 21 of array 11 .
[0038] In fact, approximate positioning of array 11 , e.g. with respect to the path of a mean point in wake 27 , may even have the opposite effect and result in a relatively low level of efficiency.
[0039] Given the possibility of theoretically determining the paths and all the parameters or quantities involved, such as flow field entropy and turbine 1 efficiency, and the possibility of simulating overall operation of the turbine, the position of array 11 may even be assigned at the turbine 1 design stage.
[0040] Clearly, changes may be made to the array positioning method as described herein without, however, departing from the scope of the present invention.
[0041] In general, the positioning or indexing method described applies to any homonymous pair of successive blade arrays having a relative velocity with respect to an intermediate array. That is, the method can also be applied in the same way to determining, as a function of the wake paths of an intermediate stator, the relative angular position of two rotors forming part of two successive stages and having the same number of blades, or one a number of blades which is a multiple of the other.
[0042] Moreover, since gas flow varies as a function of the radial position examined in gaps 15 , 16 , 17 with respect to axis 2 , the indexing method described can be applied to a number of arrays set to different radial positions in a stator or rotor.
[0043] Depending on gas flow conditions and the type of turbine involved, each wake 27 may be broken into more than two different zones, or may comprise only one zone of relatively high entropy, which is determined accurately using the method described.
[0044] As opposed to having the same number of blades, one of arrays 9 , 11 may have a number of blades which is a multiple of the other.
[0045] Finally, the wake zone with which to align the leading edges 21 of blades 14 may be selected as a function of parameters or quantities other than those indicated. | A method of positioning arrays of stages of a turbine, particularly for aircraft engines; the turbine having an axis and a first, a second and a third array of blades arranged consecutively, and of which the first and third array have a relative velocity about the axis with respect to the second array; the method including the steps of determining the paths of wakes moving inside gaps defined by the blades in the second array and towards the third array; distinguishing, for each wake, a first and at least one second zone differing from each other; selecting one of the first and second zone; and regulating the position of the third array with respect to the first array by aligning the leading edges of the blades in the third array with the paths of the selected wake zones. | 8 |
TECHNICAL FIELD
This invention relates to programmable integrated circuits and to the technique used to program the circuit.
BACKGROUND OF THE INVENTION
Although most integrated circuits today are general purpose circuits, such as memories, processors, etc., special purpose integrated circuits are frequently needed for particular applications. Severel techniques have been developed to make such circuits. One technique makes a complete set of masks for the lithographic patterning necessary to make the circuit, i.e., it follows the techniques used for the general purpose circuits. This technique is used to make what are commonly referred to as application specific integrated circuits. These circuits are usually referred to by the acronym ASIC. Such circuits are advantageously employed in many diverse applications.
While ASICs are perfectly adequate for many applications, their manufacture requires the fabrication of a complete mask set which frequently involves substantial expense. Additionally, the manufacturing process may require substantial time. These factors are frequently not important when many integrated circuits are fabricated. However, other techniques which are either cheaper or quicker than the technique described for ASICs are desirable for circuits that are made in relatively small numbers or which must be made rapidly. One such technique makes what are referred to as field programmable circuits. Such circuits may be either logic arrays or gate arrays and are frequently referred to by the acronyms FPLA and FPGA, respectively.
These circuits are customized for their particular uses by selectively closing electrical paths in the circuit, i.e., by programming the circuit. The element used to close the electrical circuit is termed an antifuse and it is an element that changes from a high resistance OFF state to a low ON state upon application of an appropriate electric voltage. In the usual circuit, the antifuses are located directly in the memory or logic circuit. That is, the antifuse may constitute the memory element or it may be used to selectively connect various devices. This technique for programming the circuit is simple and straightforward. Programming circuits, including two high voltage transistors, are required for each bit in addition to the single antifuse. High voltage in this context means a voltage significantly higher than the 5 volts commonly used in integrated circuits.
There are, however, drawbacks to including the antifuse directly in the logic or memory circuit, as described. For example, significant chip area is required for the two high voltage transistors needed for each bit. Additionally, the antifuse ON state resistance is a critical circuit parameter and may be either too high or not easily controlled.
SUMMARY OF THE INVENTION
A programmable integrated circuit comprising first and second pluralities of transistors, each having gate, source, and drain electrodes; column and row address select switches; said gates of said first and second pluralities being connected to said column and row address select switches, respectively; a plurality of programmable circuits, each circuit being connected to the source/drain of one transistor of said first plurality and of one transistor of said second plurality; each circuit comprising a transistor having gate, source and drain electrodes, first and second programmable elements connected in series; said gate electrode being connected to the common connection of said first and second programmable elements, and, said source and drain electrodes being connected to the logic path. The first and second programmable elements are connected to the source/drain electrodes of transistors of said first and second pluralities, respectively. The logic paths run through the programmable elements. In a preferred embodiment, the progammable elements are antifuses. In a further preferred embodiment, the circuit further comprises a resistor connected between the gate and drain of said transistor.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of a field programmable circuit according to this invention; and
FIG. 2 is a schematic representation of the antifuse programming circuit for an integrated circuit according to this invention.
DETAILED DESCRIPTION
FIG. 1 is a schematic representation of one embodiment of a programmable array according to this invention. Depicted are a first plurality of transistors, 101, 102, 103, . . . , 10n, and a second plurality of transistors 201, 202, . . . , 20n. Each transistor has gate, source, and drain electrodes. The first and second pluralities are used to select the columns and rows; i.e., the gates of the first and second pluralities are connected to column and row address switches, respectively. For each bit, there is a programmable circuit 301 which will be described in detail with respect to FIG. 2. Logic paths 302 run through the programmable circuits 301. Each programmable circuit represents a bit, and each circuit is connected to the source/drain electrode of both a row and a column transistor.
FIG. 2 schematically depicts an exemplary embodiment of a progammable circuit according to this invention for a single bit location. In addition to the elements described with respect to FIG. 1, the element depicted include the elements of circuit 301. The elements of the circuit depicted include a series circuit of first progammable element 3 and second programmable element 5, which have a common connection and are connected to the source/drain electrodes of transistors of the first and second pluralities, respectively. In the embodiment depicted, the programmable elements comprise antifuses. First plurality transistor 1 has its drain/source connected to either V pp or V ss and second plurality transistor 7 has its source/drain connected to ground. The gate electrodes of the transistors of the first and second pluralities are connected to V ss when programming is not being performed. The circuits also includes third transistor 9 and the logic path is through this transistor which has its gate electrode connected to the common connection of first and second antifuses 3 and 5. A load resistor 11 is connected to the gate and drain electrode of the third transistor. The third transistor, having source and drain electrodes connected to the logic path, is the only element depicted in the logic path.
Programming of the antifuse is easily accomplished. The source of the first transistor is taken to the programming voltage V pp . This is typically between 10 and 20 volts, although the precise value will depend upon the antifuse structure. The desired bit is selected by selecting the addresses of both the desired row and column, i.e., the row address select and the column address select are taken to a positive voltage, V ss . This applies a voltage to the gates of the first and second transistors which turns them ON, i.e., a voltage is established across the elements of the series cicuit and both antifuses are programmed. The antifuse will have resistances typically in the range of thousands of ohms after programming.
The gates of the transistor of the first and second pluralities, as well as the source of the first transistor, are now connected directly to V ss . These transistors are now ON and the first and second antifuses function as a voltage divider and apply a voltage to the gate of the third transistor which turns it ON. If the antifuses have not been programmed, the load resistor applies a voltage which is close to ground to the gate of the third transistor. This is desirable because it reduces the probability of noise turning ON the third transistor. The value of the load resistor is selected to reduce the current drain of the programmed bit.
The details of the antifuses need not be described as they are well known to those skilled in the art. For example, high resistivity amorphous silicon adjacent a layer of, e.g., Ti:W, or layers of Ti:W and Ti may be used in the antifuses. A sufficiently high voltage renders the antifuse conducting. It is hypothesized that silicide regions are formed. Those skilled in the art will readily fabricate the antifuses and the circuitry depicted and described.
The circuit depicted has several advantages over the circuit previously described with respect to the prior art. The approach of this invention uses the antifuses to establish a voltage on the gate of the third transistor with a very high resistance. This reduces the current drain. Accordingly, only a relatively low current is required to program the bits. The high voltage needed for programming is seen by only the first transistor while the second transistor has a normal breakdown. The chip area required for the second transistor is reduced because a high resistance is typically achieved with a large area. As will be readily appreciated by those skilled in the art, an even more significant reduction in chip area is achieved because the programming transistors, i.e., the first and second transistors, are needed only for each row and for each column and not for each bit.
Variations in the embodiment described are contemplated. For example, the programmable elements could comprise fuses. | A programmable circuit uses antifuse to program the circuit with the antifuses located not in the logic path but located so they control the voltage applied to the gate electrode of a transistor located in the logic path. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device having a MOS transistor structure and a method of manufacturing the same.
With a recent increase in the integration density of semiconductor devices, miniaturization of the elements has been accelerated. However, with the miniaturization of the device, various problems have been raised. For example, when an MOS transistor is miniaturized, the junction depth of a source/drain diffusion layer is reduced, with the result that the sheet resistance of the source/drain diffusion layer rapidly increases and the operation rite thus significantly decreases.
To describe this problem more specifically, when a source/drain diffusion layer (0.2 μm in depth) is formed by diffusing impurity ions in a concentration of 1×10 20 cm -3 , the sheet resistance becomes as large as 100 ohm/square or more. To solve the problem, a so-called SALICIDE (Self-aligned Silicide) technique has been intensively studied in recent years.
FIG. 1 is a cross sectional view of a conventional MOS transistor formed by the SALICIDE technique. The steps of manufacturing the MOS transistor will be explained below in the order of manufacturing. An element isolation film (SiO 2 film) 801 is first formed selectively on a silicon substrate 800 by a well-known LOCOS method. Subsequently, a gate Insulation film 811, a gate electrode 802, an upper gate-insulation film 809, and a side wall gate-insulation film 810 are formed, and a shallow source/drain diffusion layer 803 (0.15 μm in depth) is formed by ion implantation.
After a Ti film (30 nm) is deposited over the entire surface of the resultant structure by sputtering, the substrate is subjected to heat treatment called a rapid thermal annealing (RTA) in a nitrogen atmosphere for 30 seconds at 700° C. As a result, a TiSi 2 film 804 is formed between the source/drain diffusion layer 803 and the Ti film.
The Ti film remaining unreacted on an insulation film including the element isolation film 801 is selectively removed with a mixed solution of sulfuric acid and hydrogen peroxide. Subsequently, an interlayer insulation film (SiO 2 film) 805 is formed over the entire surface of the resultant structure.
After a contact hole is made in the interlayer insulation film 805, a buried electrode 806, an upper electrode wiring layer 807, and an upper insulation film (SiO 2 film)808 are formed. The MOS transistor is thereby manufactured.
As is described above, by virtue of the presence of the TiSi 2 film 804 formed on the source/drain diffusion film 803, the source/drain region exhibits a sheet resistance of 5 ohm/square. This sheet resistance is 1/20 or less of the sheet resistance of the source/drain region in the absence of the TiSi 2 film 804. Therefore, the formation of the TiSi 2 film contributes to a decrease in the sheet resistance, ensuring the high speed operation of a miniaturized semiconductor device.
However, as the results of the intensive studies on the SALICIDE technique, the presence of the following problems have been confirmed. When the gate length becomes 0.2 μm or less with the miniaturization, the depth of the source/drain diffusion layer must be set as shallow as 0.1 μm or less, to suppress the short channel effect.
When the source/drain diffusion layer 803 is formed shallow, it is destroyed to increase a junction leakage. This is because Si is consumed when the source/drain diffusion layer 803 (Si) reacts with the Ti film to form an alloy (TiSi 2 ) film 804.
To prevent an increase of the junction leakage, it is effective to reduce the Si consumption by reducing the thickness of TiSi 2 film 804. If the Si consumption is reduced, the sheet resistance of the source/drain region inevitably increases, making it difficult to attain the anticipated object, an improvement of the operation rate.
The source/drain diffusion layer 803 is usually formed by ion implantation. For example, BF 2 + ions are implanted at 10 keV in a dose of 8×10 14 atoms/cm 2 and subjected to heat treatment for 30 minutes at 900° C. In this manner, the source/drain diffusion layer 803 can be formed with a depth of about 0.09 nm. The depth is defined as the distance from the surface of the substrate to a position where a boron concentration is 1×10 17 atoms/cm 3 .
However, the ion implantation method has problems. There is a limitation in lowering the implantation speed. A profile changes at the time of implantation and activation of the ions. Hence, the shallow source/drain diffusion layer with a low resistance cannot be formed without limitation.
To deal with this problem, a technique has been recently proposed comprising the steps of absorbing an impurity such as boron in a substrate or depositing a thin film containing an impurity on a substrate, and diffusing the impurity into the substrate by a brief heat treatment performed at a high-temperature, thereby forming the shallow source/drain diffusion layer with a low resistance. However, this method requires a technique for adsorbing an impurity or depositing the impurity-containing thin film selectively to a desired region.
In the case of the ion implantation, impurity ions can be selectively injected only into a desired source/drain formation region by using a resist as a mask. However, it is extremely difficult to isolate and process the impurity-adsorbing region or an impurity-containing thin film formed on a gate electrode by use of the resist mask since the gate electrode is formed in the lowermost dimensions. In the regions other than the region on the gate electrode, a sufficient margin must be maintained to compensate for a lithographic misalignment relative to the proximity of the gate electrode, for example, to the source/drain region. Therefore, in the ion implantation method, techniques are also required for selectively absorbing an impurity and for selectively depositing a thin film.
As one of the selective deposition techniques, known is a technique for depositing the impurity-containing thin silicon film by thermally decomposing a mixed gas consisting of a source gas containing a silicon material (e.g. dichlorsilane or a silane gas) and an impurity-containing gas, (e.g. a di-borane gas).
However, such a selective deposition technique has the following problems:
Deposition must be performed at a relatively high temperature;
The deposited thin silicon film is epitaxially grown;
The gas used herein is limited in type; and
Gas-flow amount, temperature, atmosphere and the like defining the deposition selectivity are limited to narrow ranges.
The selective deposition technique is not an established technique as mentioned above and may therefore affect the reliability of the transistor characteristics.
To sum up, in the conventional SELICIDE technique, there is a problem in that a junction leakage increases as the junction depth of source/drain diffusion layer becomes shallow since the source/drain diffusion layer is destroyed due to the Si consumption of the source/drain diffusion layer at the time the silicide film is formed.
As one of techniques for forming a shallow source/drain diffusion layer except for the ion implantation, known is a method enabling selective depositing of an impurity-containing thin silicon film. However, this method is not suitable in practice because a process temperature is relatively high, the gas-flow amount, temperature, atmosphere, and the like are limited to narrow ranges.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to effectively provide a semiconductor device having a miniaturized source/drain region, and a method of manufacturing the same.
To attain the aforementioned object, a semiconductor device according a first aspect of the present invention comprises
a semiconductor substrate having an element region;
an element isolation film formed on the semiconductor substrate so as to surround the element region;
a gate portion crossing the element region and extending over the semiconductor substrate, the gate portion comprising at least a gate insulation film formed on the semiconductor substrate and a gate electrode formed on the gate insulation film; and
source/drain regions formed in the surface of the element region on both sides of the cate portion,
wherein an upper surface of the element isolation film is formed in substantially the same plane as an upper surface of the gate portion.
In the present invention, when the gate electrode is formed of a polycrystalline silicon, and the gate portion further comprises a refractory metal film on the gate electrode, an upper surface of the refractory metal film is formed in substantially the same plane as the upper surface of the element isolation film.
When the gate portion further comprises an upper insulation film on the gate electrode, the upper surface of the upper insulation film is in substantially the same plane as the upper surface of the element isolation film.
The gate portion is preferred to further comprise a side-wall insulation film covering a side wall of the gate portion.
The semiconductor device of the present invention further may comprise a conductive film formed on each of the source/drain regions surrounded with the gate portion and the element isolation film. It is preferable that the conductive film be electrically isolated from the gate electrode by the side wall insulation film.
In this case, at least part of the conductive film is formed in substantially the same plane as the upper surface of the gate portion.
An interlayer insulation film may be formed on the conductive film. An upper surface of the interlayer insulation region may be formed in substantially the same plane as an upper surface of the element isolation film.
When the semiconductor substrate is a single crystal semiconductor substrate, the conductive film may be an epitaxially-grown film made of an alloy of a semiconductor constituting the semiconductor substrate and a transition metal.
When the semiconductor substrate is formed of silicon, the conductive film may be formed of silicon containing an impurity, and the concentration of the impurity contained in the conductive film is preferably larger than the solid solubility of silicon.
The semiconductor device according to a second aspect of the present invention comprises
a semiconductor substrate having an element isolation region;
an element isolation region formed on the semiconductor substrate so as to surround the element region;
a gate portion crossing the element region and extending over the semiconductor substrate, the gate portion comprising a gate insulation film formed on the semiconductor substrate, a gate electrode formed on the gate insulation film, an upper insulation film formed on the gate electrode, and a side-wall insulation film formed on the side-wall of the gate electrode; and
source/drain regions formed in a surface of the element regions on both sides of the gate portion;
wherein an upper surface of the element isolation film and at least part of upper surfaces of the source/drain regions are formed in substantially the same plane as upper surface of the gate portion.
In the semiconductor device of the present invention, the semiconductor substrate is formed of silicon, the source/drain regions are formed of silicon containing an impurity, and a concentration of the impurity contained in the source/drain regions is larger than the solid solubility of silicon.
The element isolation region may be formed of a construct having the same structure as that of the gate portion, formed on an insulation film.
A method of manufacturing semiconductor device according to a third aspect of the present invention comprises the steps of
forming an element isolation film on a semiconductor substrate so as to project from the semiconductor substrate to form an element region surrounded with the element isolation film;
forming a gate portion on the semiconductor substrate of the element region in such a manner that an upper surface of the gate portion is formed in substantially the same plane as an upper surface of the element isolation film;
forming a pair of source/drain diffusion layers mutually opposed with the gate portion interposed therebetween, on a surface of the semiconductor substrate in the element region;
forming a conductive film on an entire surface of the substrate so as to be in contact with a pair of source/drain diffusion layers; and
burying the conductive film between the element isolation film and the gate portion by polishing the conductive film after the step of forming the conductive film.
The step of forming a gate portion may comprise the steps of
forming a gate insulation film on the semiconductor substrate;
forming a first gate electrode on the gate insulation film;
forming an upper insulation film on the first gate electrode; and
forming a side-wall insulation film on a side face of the first gate electrode.
After the upper insulation film is removed, a second gate electrode may be buried in the upper insulation film removed portion.
The conductive film is preferred to be formed of an amorphous silicon. The step of forming the conductive film preferably comprises a single-crystallization step of the amorphous silicon with heat treatment.
The conductive film may include a transition metal. The step of forming the conductive film comprises a step of epitaxially growing an alloy of a semiconductor constituting the semiconductor substrate and the transition metal.
A method of manufacturing a semiconductor device according to a fourth aspect of the present invention comprising the steps of
forming a gate portion on a semiconductor substrate;
forming an insulation film on an entire surface of the substrate so as to cover the gate portion;
flattening the insulation film to a height of the gate portion;
forming an opening portion in the insulation film to expose a surface of the semiconductor substrate in the source/drain layer formation region;
forming a conductive film over the entire surface; and
leaving the conductive film in the opening.
The conductive film may be formed of an amorphous silicon containing an impurity. The step of forming the conductive film comprises a single-crystallization step of the amorphous silicon with heat treatment.
Alternatively, the conductive film may be formed of silicon containing an impurity,
the step of forming an opening in the insulation film may comprise a step of forming a depressed portion by etching the surface of the semiconductor substrate of a bottom of the opening portion, and
the step of forming a conductive film over the entire surface may comprise a step of forming the silicon layer containing an impurity so as to bury it in the depressed portion.
The step of leaving the conductive film may comprise a step of leaving the silicon layer at least in the depressed portion.
If the structure of the first aspect of the present invention is employed, the conductive film for reducing the resistance of the source/drain region can be buried by polishing in a self-alignment manner according to a third aspect of the present invention. Since silicon of the source drain diffusion layer is not needed to react with a refractory metal, while it is needed in the prior art, the silicon of the source/drain diffusion layer is not eroded in theory. By virtue of this feature, the resistance of the source/drain region can be sufficiently reduced by the conductive film of the present invention even if the junction of source/drain diffusion layer is shallow.
According to the method of manufacturing a semiconductor device according to the fourth aspect of the present invention, the conductive film is left selectively within the opening (source/drain region) for example, by polishing after the conductive film is formed over the entire surface. Hence, compared to the conventional selective deposition technique, the semiconductor film or the like can be formed in the source/drain region by a method with less limitation. Furthermore, if the semiconductor film containing an impurity is used as the conductive film, the source/drain layer can be formed by diffusing the impurity in the semiconductor substrate with heat. Since a concentration profile of the impurity can be controlled well in this method, the impurity can be doped into the surface of the semiconductor substrate so as to be shallow and in a high concentration. As a result, a and low resistant source/drain layer can be formed.
The step of leaving the semiconductor film or the like selectively in the opening can be performed in a self-aligning manner by polishing the semiconductor film formed over the entire surface. In this way, even if the gate has a length of the lowermost processing dimensions, the semiconductor film or the like can be separated on the gate portion without fail.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a cross sectional view of an MOS transistor formed by a conventional SALICIDE technique;
FIGS. 2A-2L are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 1 of the present invention;
FIGS. 3A-3H are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 2 of the present invention;
FIGS. 4A-4H are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 3 of the present invention;
FIGS. 5A-5G are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 4 of the present invention;
FIG. 6 is a graph showing the relationship between the junction depth and the sheet resistance in the boron-doped silicon diffusion layers of the present invention in comparison with the diffusion layer formed by a conventional ion implantation method;
FIGS. 7A-7H are cross sectional views of an MOS transistor, sequentially showing the manufacturing steps of a MOS transistor according to a modified example of Embodiment 3 of the present invention;
FIGS. 8A and 8B are cross sectional views of an MOS transistor, showing a manufacturing method of an MOS transistor according to Embodiment 5 of the present invention, in two steps;
FIGS. 9A-9D are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 6 of the present invention;
FIGS. 10A-10E are cross sectional views of an MOS transistor sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 7 of the present invention;
FIGS. 11A-11E are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 8 of the present invention;
FIGS. 12A-12E are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 9 of the present invention;
FIGS. 13A-13Q are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 10 of the present invention;
FIGS. 14A and 14B are cross sectional views of an MOS transistor showing a modified example of Embodiment 10 of the present invention;
FIGS. 15A-15L are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 11 of the present invention;
FIGS. 16A-16D are plan views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 12 of the present invention;
FIGS. 17A-17D are plan views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 13 of the present invention;
FIG. 18A is a schematic plan view showing a MOS transistor according to Embodiment 14 of the present invention;
FIG. 18B is a cross sectional view taken along the line 18B-18B of FIG. 18A;
FIG. 18C is a cross sectional view taken along the line 18C-18C of FIG. 18A;
FIGS. 19A and 19B are plan views of a transistor for explaining the basic concept for the construction of the MOS transistor according to Embodiment 14;
FIGS. 20A and 20B are plan views of a transistor for explaining the basic concept for the another construction of the MOS transistor according to Embodiment 14;
FIGS. 21A to 21C are plan views of a transistor showing the method for reducing the difference in gate length caused by the alignment error between a gate electrode and a mask for source/drain formation;
FIGS. 22A to 22U are plan views of a MOS transistor sequentially showing the details of a method of forming the MOS transistor shown in FIGS. 19A and 19B; and
FIGS. 23A to 23X are plan views of a transistor sequentially showing the details of a formation method of the MOS transistor shown in FIGS. 20A and 20B.
DETAILED DESCRIPTION OF THE INVENTION
Hereinbelow, Embodiments of the present invention will be explained with reference to the accompanying drawings.
(Embodiment 1)
FIGS. 2A-2L are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 1 of the present invention.
As shown in FIG. 2A, a mask pattern 102 (0.3 μm-thick) made of a silicon nitride film (Si 3 N 4 film) is formed on a <100> plane of a single crystal silicon substrate 101. The mask pattern 102 thus-formed is used for forming a buried isolation film which defines an element region of a transistor. Thereafter, the silicon substrate 101 is etched by using the mask pattern 102 as a mask. As a result, an isolation groove 103 (0.3 μm depth) is formed on the surface of the substrate.
As shown in FIG. 2B, a SiO 2 film 104 (about 1.5 μm thick) serving as the buried isolation film is then formed over the entire surface. The SiO 2 film 104 is formed by the CVD (chemical vapor deposition) method using a gas mixture of, for example, a TEOS (tetraethylorthosilicate) gas and an ozone (O 3 gas.
As shown in FIG. 2C, the SiO 2 film 104 is polished by the CMP (Chemical Mechanical Polishing) method until the surface of a mask pattern (Si 3 N 4 film) 102 is exposed and the polished surface is flattened. Thereafter, the mask pattern (Si 3 N 4 film) 102 is removed with a heated H 3 PO 4 solution.
As a result, a transistor formation region 105 is formed which is surrounded with the buried isolation film (SiO 2 film) 104. The buried isolation film 104 projects with a height of about 0.3 μm from the surface of the substrate, as shown in the figure.
As shown in FIG. 2D, to form a gate portion, an insulation film (5 nm thick) for forming a gate insulation film 106, a phosphorus-doped polycrystalline silicon film (10 nm thick) for forming a gate electrode 107, and a BPSG (Boron-Doped Phosphosilicate Glass) film (200 nm thick) for forming an upper gate-insulation film 108 are sequentially deposited and then patterned. As a result, the gate insulation film 106, the gate electrode 107 and the upper gate-insulation film 108 are formed.
The width of the gate electrode 107 is, for example, 0.15 nm. The upper surface of the upper gate-insulation film 108 is formed in almost the same plane as the upper surface of the buried insulation film 104. Subsequently, an Si 3 N 4 film (30 nm thick) for a side wall gate-insulation film 109 is deposited over the entire surface. The entire surface of the Si 3 N 4 film is then etched by means of anisotropic etching such as an RIE (Reactive Ion Etching) method. Consequently, the side wall gate-insulation film (Si 3 N 4 film) 109 is formed. At this point, the Si 3 N 4 film 109 is also left on the side wall of the buried isolation film 104, as shown in the figure.
As shown in FIG. 2E, impurity ions are injected into the surface of the substrate by using the gate portion (consisting of members 106, 107, 108 and 109) as a mask. The injected impurity ions are activated by heat treatment, thereby forming a source/drain diffusion layer 110.
If impurity ions are injected into the substrate surface by use of the gate portion (consisting of the members 106, 107, and 108) as a mask prior to forming the source/drain diffusion layer 110, or prior to forming the side-wall gate-insulation film 109, the source/drain diffusion layer 110 having an LDD (lightly Doped Drain) structure can be formed. After the substrate surface is cleaned with Ar ions having energy as low as 100 ev or less, the surface of the substrate obtained is cleaned with no native oxide formed thereon.
As shown in FIG. 2F, a nickel silicide (NiSi 2 ) film 111 (about 0.4 μm thick) is deposited over the clean surface by a directional sputtering method. Subsequently, the NiSi 2 film 111 is polished by the CMP method until the buried isolation film 104 and the upper gate-insulation film 108 are exposed, and then, the surfaces of the polished films are flattened. In this way, the NiSi 2 film 111 is allowed to remain selectively in the source/drain region between the gate portion and the buried isolation film 104.
Since the Si 3 N 4 film 109 on the side walls of the gate portion and the buried isolation film 104 is provided in a tapered form, there are no side-wall portions perpendicular to the substrate in the element formation region. Accordingly, the NiSi 2 film 111 can be uniformly deposited on the element formation region even if a directional sputtering method is employed. However, the NiSi 2 film 111 of this stage is in a polycrystalline state with an irregular crystalline orientation.
After only the upper portion of the NiSi 2 film 111 is selectively etched to the depth of about 50 nm by the CDE (Chemical Dry Etching) method, annealing is performed in a nitrogen atmosphere at 550° C. for 30 minutes. In this step, the polycrystalline NiSi 2 film 111 deposited by the sputtering method is epitaxially grown in the same <100> orientation as that of the silicon substrate 101. As a result, single crystal NiSi 2 film 111 is formed on the source/drain diffusion layer 110.
As shown in FIG. 2G, after the Si 3 N 4 film 112 is formed over the entire surface, the Si 3 N 4 film is polished and flattened by the CMP method. As a result, the Si 3 N 4 film 112 is selectively buried only in a thickness-reduced region of the NiSi 2 film by the CDE method performed above. Through the aforementioned steps, the single crystal NiSi 2 film 111 (for lowering the resistance of the source/drain region) is formed on the source/drain diffusion layer 110, in a self-alignment manner.
The NiSi 2 film 111 is formed without reacting Si of the source/drain diffusion layer with Ni in this embodiment, unlike a conventionally-employed SALICIDE technique. Since Si of the source/drain diffusion layer is not consumed, a junction leakage will not take place even if the depth of the source/drain is shallow.
As shown in FIG. 2H, the upper gate-insulation film (BPSG film) 108 is selectively removed by etching using hydrofluoric acid vapor treatment. As a result, a wiring groove 118 is formed on the gate electrode 107.
As shown in FIG. 2I, to form a TiN barrier metal film 119, a tungsten wiring 120, titanium nitride (TiN) film and a tungsten (W) film are sequentially formed over the entire substrate surface by the CVD method. The TiN film and the tungsten film are polished by the CMP method until the surfaces of the Si 3 N 4 film 112 and the buried isolation film 104 are exposed, and then the surface of the polished films is flattened. In this manner, the TiN barrier metal film 119 and the tungsten wiring 120 are formed in the wiring groove 118. At this time, the upper surface of the tungsten wiring 120 is formed in almost the same plane as the upper surface of the buried isolation film 104.
As shown in FIG. 2J, after an interlayer insulation film 121 made of e.g. SiO 2 film, is formed over the entire surface, a contact hole 122 and an upper layer wiring groove 123 corresponding to the gate portion, are formed within the interlayer insolation film 121. In this case, the contact hole 122 is formed in the region surrounded with the buried isolation film 104. Either contact hole 122 or the upper wiring groove 123 may be formed first. In this embodiment, since the NiSi 2 film 111 is covered with Si 3 N 4 film 112, the contact hole 122 is prevented from reaching the NiSi 2 film 111.
As shown in FIG. 2K, a contact hole 124 and an upper wiring groove 125 corresponding to the source/drain diffusion layer 110, are formed in the interlayer insulation film 121.
Finally, as shown in FIG. 2L, to form a TiN barrier metal film 126 and a tungsten film 127, a titanium nitride (TiN) film and a tungsten (W) film are formed over the entire substrate by the CVD method. Thereafter, the titanium nitride film and the tungsten film are polished by the CMP method until the surface of the interlayer insulation film 121 is exposed, and then the surfaces of those films are flattened. In this manner, a TiN barrier metal film 126 and the tungsten wiring 127 are formed in contact holes 122, 124 and the upper wiring grooves 123, 125, respectively. As a result, the MOS transistor is accomplished.
According to this embodiment, the NiSi 2 film 111 (0.2 μm thick) can be easily formed in a self-alignment manner. It was also confirmed that the sheet resistance of the source/drain diffusion layer 110 is reduced to 1.5 ohm/square or less. The Si consumption at the interface between the NiSi 2 film 111 and the shallow source/drain diffusion layer 110 can be completely suppressed. Therefore, junction leakage, which is a serious problem with the conventional technique, is not observed.
It is easy for the NiSi 2 film 111 to grow epitaxially by subjecting the substrate to low temperature heating. The source/drain diffusion layer 110 can be formed in a single crystalline state with the same orientation as that of the substrate. As a result, the interface between the NiSi 2 film 111 and the source/drain diffusion layer 110 becomes flat at an atomic level. Hence, even if the device has at least 1 million source/drain diffusion layers, the contact interface can be obtained with a uniform contact resistance. The reliability of the contact interface is thereby ensured.
When silicon is thermally reacted with nickel to form NiSi 2 , the heat treatment must be performed usually at a temperature of 700° C. or more. However, problematic projections and depressions are generated in the surface along the <111> silicon plane by the high temperature treatment. Whereas, in this embodiment, the projections and depressions will not be raised and NiSi 2 having ideal interface characteristics can be easily formed in a self-alignment manner.
According to this embodiment, the contact hole 122 reaching the gate electrode 107 can be formed in the transistor region surrounded with the buried isolation film 104. According to this embodiment, the device can be formed with higher integration density, compared to the device employing a conventional element structure requiring the formation of a contact to the electrode led on the buried isolation film 104.
In this embodiment, to form the NiSi 2 region (silicide region), a gate electrode wiring region, and an upper electrode wiring region, a buried wiring is used which is processed by the CMP method. Hence, the elements can be easily formed flat, ensuring high reliance of the device.
This embodiment can be modified in various manners. If a CoSi 2 film is used, for example, in place of the NiSi 2 film as a silicide film, the same effects can be obtained. This is because even if the CoSi 2 film is used, the single crystalline structure can be epitaxially grown with the same orientation as that of the substrate in the source/drain diffusion layer by employing the same procedure.
Furthermore, if a silicide film consisting of silicon and a transition metal other than those mentioned, such as TiSi 2 , WSi 2 , MoSi 2 , or VSi 2 , the same structure as above can be attained.
A silicide film not epitaxially grown on the substrate may be used. In this case, the silicide film is obtained with a polycrystalline structure. However, the erosion of Si at the interface between the silicide film and the substrate, can be completely suppressed, with the result that an increase of the junction leakage associated with the formation of the silicide film can be completely suppressed.
Silicide films other than the aforementioned ones may be used. Furthermore, a metal film may be used. In either case, the thickness of the silicide film or the metal film formed on the source/drain diffusion layer can be arbitrarily set, so that the value of resistance can be easily controlled for attaining desired element characteristics.
The effects of the present invention can be obtained most effectively when the silicide film is used. Instead of using the silicide film formed by the sputtering method, a laminate film of a Ti film (5 nm thick), TiN film (10 nm thick), and W film (0.3 μm thick) may be formed by the sputtering method, and then a tungsten wiring may be formed in a self-alignment manner on the source/drain diffusion layer through the same steps as those of this embodiment.
In this case, silicon (12 nm) is eroded from the surface of the silicon substrate as a result of the reaction with a Ti film (5 nm). However, the Si erosion amount is low compared to the amount eroded from the substrate formed by the conventional technique and requiring a thick TiSi 2 film. The present invention can be applied onto the shallow junction (80 nm depth) to which a conventional technique cannot be applied.
(Embodiment 2)
FIGS. 3A-3H are cross sectional views of a p-channel MOS transistor, sequentially showing the steps of manufacturing the p-channel MOS transistor according to Embodiment 2 of the present invention.
As shown in FIG. 3A, an n-type silicon substrate 201 having the <100> plane orientation is first prepared with a specific resistivity of 4-6 Ω cm. In the surface of the n-type silicon substrate 201, a groove (0.3 μm depth) is formed. In the groove, an element isolation film 202 is buried by use of a material such as TEOS. Subsequently, a gate oxide film 203 (7 nm thick) is formed by thermal oxidation. On the gate oxide film 203, an impurity-doped polycrystalline silicon film 204 (50 nm), a tungsten silicide film 205 (50 nm thick), and a silicon nitride film 206 (50 nm thick) are sequentially laminated by an LPCVD (Low Pressure Chemical Vapor Deposition) method. Consequently, a gate electrode is formed.
When these laminated film are is etched by the RIE method using a resist mask, a gate side-wall insulation film 207 made of a silicon nitride film (about 50 nm thick) is formed on the side walls of the laminated films thus etched. The gate side-wall insulation film 207 is obtained by depositing a silicon nitride film (50 nm thick) over the entire surface by, for example, the CVD method, followed by etching the entire surface by anisotropic dry etching.
As shown in FIG. 3B, a silicon oxide film 208a (about 200 nm) is deposited over the entire surface by the CVD method using TEOS. Subsequently, as shown in FIG. 3C, the entire surface is polished to the height of the gate portion and then flattened. Since the polishing rate of the silicon nitride film 206 (the top layer of the gate portion) is lower than that of the silicon oxide film 208a, the silicon nitride film 206 acts as a stopper. Hence, excessive polishing of the silicon oxide film 208a can be prevented. The silicon nitride film 206 is used as a stopper in this embodiment, however, any film may be used as long as it is capable of stopping the polishing of the silicon oxide film 208a when it reaches the same height as that of the gate electrode 204 and as long as it has no effects on the transistor characteristics.
As shown in FIG.3D, the silicon oxide film 208a on the source/drain region is removed by the RIE method using a resist mask (not shown). Consequently, an opening portion 209 is formed.
Thereafter, a native oxide film, on the exposed silicon surface of the source/drain region is removed with a dilute hydrofluoric acid solution and then, the substrate 201 is introduced in a low pressure reaction chamber.
Subsequently, for example, a disilane gas and a diluted diborane gas (10%) are introduced into the lower pressure reaction chamber at a flow rate of 20 sccm at 300° C. As a result, as shown in FIG. 3E, an amorphous silicon thin film 210 containing boron is deposited over the entire substrate surface.
To crystallize the amorphous silicon thin film 210, heat treatment is provided to the amorphous silicon thin film 210 in a nitrogen atmosphere for 2 hours at 600° C. As a result, the amorphous silicon thin film 210 on the source/drain region is single-crystallized and the amorphous silicon thin film 210 on the silicon oxide film 208a is polycrystallized.
Furthermore, boron is diffused into the substrate from the silicon thin film 210 by high-temperature and short-time heat treatment performed in a nitrogen atmosphere, with the result that a source/drain diffusion layer 211 is formed.
Since the boron-concentration profile is controlled well in this method, boron can be doped shallow with a high concentration into the surface of the substrate. As a result, a shallow and low resistant source/drain diffusion layer 211 can be formed. In addition, since the amorphous silicon thin film 210 is single-crystallized by a solid-phase growth, the heating can be performed at a low temperature and a high carrier concentration is attained. These features are advantageous in forming a shallow and low resistance source/drain layer 211. Note that the crystallization of the amorphous silicon thin film 210 and the boron diffusion into the substrate may be performed simultaneously in a single heat treatment step.
Then, the entire surface of the substrate is polished with a polishing agent made of alkali colloidal silica (pH 10-11). Since the polishing rate of the polycrystalline silicon is 0.5 μm/min and the polishing rate of the silicon oxide film is 1/100 or less of the polycrystalline silicon, the boron-containing silicon thin film 210 can be allowed to remain only in the opening on the source/drain region, as shown in FIG. 3F. More specifically, the silicon thin film 210 formed over the entire surface can be left selectively in the opening by polishing in a self-alignment manner. In this manner, the silicon thin film 210 can be separated on the gate portion even if the gate length is formed in the lowermost dimensions.
In the step of or the step related to forming the source/drain diffusion layer, the margin for lithographic misalignment can be lowered. Accordingly, the source/drain diffusion layer can be formed in almost the same dimensions as those of the gate electrode. As a result, the miniaturization of the device can be attained.
As shown in FIG. 3G, a titanium thin film of 25 nm thick (not shown), and a titanium nitride thin film of 50 nm thick (not shown) are sequentially deposited by sputtering. Thereafter, the entire titanium thin film is reacted with the silicon thin film 210 (source/drain diffusion layer) in 1-minute heat treatment in a nitrogen atmosphere at 700° C. to form a titanium silicide film 212 only on the source/drain region.
The unreacted titanium thin film remaining on the insulation film including the titanium nitride film and the silicon oxide film 208a is selectively removed with a mixed solution of an aqueous hydrofluoric acid solution, sulfuric acid and hydrogen peroxide.
The silicon thin film 210 deposited on the source/drain diffusion region 211 is uniformly deposited on the inner surface of the opening. In a selectively grown epitaxial film in a conventionally employed method, a facet is produced at the end portion of the surface of the source/drain layer. Therefore, the substantial thickness of the facet is reduced with the result that the reliability of the source/drain diffusion layer 211 is decreased by the Si consumption at the time of the formation of the titanium silicide film 212. However, in this embodiment, it is possible to avoid decrease in the reliability caused by the aforementioned reason.
As shown in FIG. 3H, after a silicon oxide film 208b (about 200 nm) is deposited over the entire surface by the CVD method using TEOS, the silicon oxide film 208b is patterned by using a resist mask (not shown), thereby forming a contact hole on the source/drain region. Subsequently, an aluminium film (800 nm) containing silicon and copper contained in an amount of 0.5% for each is formed and then patterned to form a source/drain electrode 213. Thereafter, heat treatment is performed in a nitrogen atmosphere containing hydrogen (10%) for 15 minutes at 450° C. (Embodiment 3)
FIGS. 4A-4H are cross sectional views of a p-channel MOS transistor, Sequentially showing the steps of manufacturing the p-channel transistor according to Embodiment 3 of the present invention.
As shown in FIG. 4A, an n-type silicon substrate 221 having the <100> plane orientation is prepared with a specific resistivity of 4-6 Ωcm. On the surface of the n-type silicon substrate 221, a groove (about 0.3 μm depth) is formed. Then, an element isolation film 222 is buried in the groove by use of a material such as TEOS. Thereafter, the same procedure as in Embodiment 2 is repeated to form a gate portion consisting of a gate oxide film 223, impurity-doped polycrystalline silicon film 224, tungsten silicide film 225, silicon nitride film 226, and side-wall silicon nitride film 227.
As shown in FIG. 4B, after silicon oxide film 228a (about 200 nm) is deposited over the entire substrate surface by the CVD method using TEOS, the surface of the substrate is polished to the same height as that of the gate portion and flattened, as shown in FIG. 4C.
As shown in FIG. 4D, using a resist patterned mask (not shown), the silicon oxide film 228a on the source/drain region is removed by the RIE, to form an opening 229.
After the native oxide film on the exposed silicon substrate of the source/drain region is removed with a dilute hydrofluoric acid solution, the substrate 221 is introduced into a low pressure reaction chamber 221. On the surface of the substrate 221 in the low pressure reaction chamber 221, active species generated by a micro-wave discharge of a carbon tetrafluoride gas (CF 4 gas) is supplied. As a result, the exposed silicon surface of the source/drain region is selectively etched to a desired depth in an isotropic manner. In this way, a shallow groove is formed in the substrate surface. Owing to the selective isotropic etching, the source/drain region is formed in such a manner that it enters under the side wall gate-insulation film. Therefore, a silicon thin film containing an impurity (which will be formed in a later step) can be introduced into the portion under the side wall gate-insulation film. As a result, a junction interface having a steep impurity distribution profile can be positioned in the proximity of the channel. As a result, the parasitic resistance between the source and the drain can be reduced.
Now, we will change the subject to a film-formation step of the silicon thin film in a vacuum or a non-oxidative atmosphere.
As shown in FIG. 4E, a disilane gas and a diluted (10%) diborane gas are first supplied to a film-formation chamber at a flow rate of 100 sccm and 20 sccm, respectively at 300° C. In this manner, an amorphous silicon thin film 230 containing boron is formed over the entire surface of the substrate.
To crystallize the amorphous silicon thin film 230, heat treatment is applied to the amorphous silicon thin film 230 in a nitrogen atmosphere for 2 hours at 600° C. As a result, the amorphous silicon thin film 230 on the source/drain region is single-crystallized, whereas, the amorphous silicon thin film 230 on the silicon oxide film 228a is polycrystallized. In this case, since the amorphous silicon thin film 230 is deposited, the single crystallization can be performed at a temperature as low as 600° C. Furthermore, the concentration of the carrier can be increased more than the solid solubility of silicon, so that the resistance of the single crystalline silicon thin film 230 serving as the source/drain layer, can be reduced.
When the amorphous silicon thin film 230 is formed under the aforementioned conditions, for example, with the heat treatment performed in the boron concentration of about 1×10 21 atoms/cm 3 , for 2 hours at 600° C., a carrier concentration of about 4×10 20 atoms/cm 3 is obtained. Since the solid solubility of boron at 600° C. is about 6×10 18 atoms/cm 3 , the boron concentration and the carrier concentration can be increased higher than those conventionally obtained ones.
As shown in FIG. 4F, the entire surface of the substrate is polished by a polishing agent made of alkali colloidal silica maintained at pH 10-11. As a result, the boron-containing silicon thin film 230 serving as a source/drain layer is allowed to remain only in the opening on the source/drain region.
As shown in FIG. 4G, after a titanium thin film of 25 nm thick (not shown) and a titanium nitride thin film of 50 nm thick (not shown) are sequentially deposited over the entire surface, a heat treatment is performed in a nitrogen atmosphere for one minute at 700° C. As a result, the entire titanium thin film can react with the silicon thin film (source/drain layer) 230 to form a titanium silicide film 232 only on the source/drain layer 230.
Thereafter, an unreacted titanium thin film on the insulation film such as a titanium nitride film and the silicon oxide film 228a is selectively removed with a mixed solution of an aqueous hydrofluoric acid, sulfuric acid and hydrogen peroxide. As the silicon thin film 230 thus formed becomes thinner, the titanium silicide film 232 comes closer to the channel. Hence, the parasitic resistance between the source and the drain can be reduced.
In this Embodiment and Embodiment 2, titanium is used as a metal for forming a silicide. The same effect can be obtained even if another metal such as nickel, cobalt, platinum, vanadium, or palladium is used. Since the amount of the silicon thin film consumed in the silicide reaction varies depending on the type of metal used and film thickness, the silicon thin film must be formed thicker than the thickness to be consumed.
As shown in FIG. 4H, a silicon oxide film 228b (about 200 nm) is deposited over the entire surface of the substrate by the CVD method using TEOS, and patterned by use of a resist mask (not shown). Consequently, a contact hole is formed in the source/drain diffusion layer 230.
Subsequently, an aluminum film (800 nm) having silicon and copper in an amount of 0.5 % for each is formed and patterned to form a source/drain electrode 233. Thereafter, a heat treatment is performed in a nitrogen atmosphere containing hydrogen (10%) for 15 minutes at 450° C.
In this embodiment, the same effects as in Embodiment 2 can be obtained. (Embodiment 4)
FIGS. 5A-5G are cross sectional views of a p-channel MOS transistor, sequentially showing the steps of manufacturing the p-channel MOS transistor according to Embodiment 4 of the present invention.
As shown in FIG. 5A, an n-type silicon substrate 241 having the <100> plane orientation is prepared with a specific resistivity of 4-6 Ωcm. On the surface of the n-type silicon substrate 241, a groove (about 0.3 μm) is formed. Then, an element isolation film 242 is buried in the groove by use of a material such as TEOS. Thereafter, the same procedure as in Embodiment 2 is repeated to form a gate portion consisting of a gate oxide film 243, impurity-doped polycrystalline silicon film 224, tungsten silicide film 245, silicon nitride film 246, and side-wall silicon nitride film 247.
As shown in FIG. 5B, after silicon oxide film 248a (about 200 nm) is deposited over the entire substrate by the CVD method using TEOS, the surface of the substrate is polished to the same height as that of the gate portion and then flattened, as shown in FIG. 5C.
As shown in FIG. 5D, using a resist patterned mask (not shown), the silicon oxide film 248a on the source/drain region is removed by the RIE method, to form an opening 249.
After the native oxide film on the exposed silicon substrate of the source/drain region is removed with a dilute hydrofluoric acid solution or the like, the substrate 241 is introduced into a low pressure reaction chamber. On the surface of the substrate 241 in the low pressure reaction chamber, active species generated by a micro-wave discharge of a carbon tetrafluoride gas (CF 4 gas) is supplied. As a result, the exposed silicon surface of the source/drain region is selectively etched to a desired depth in the same manner as Embodiment 3.
Now, we will change the subject to a film-formation step of the silicon thin film in a vacuum or a non-oxidative atmosphere.
As shown in FIG. 5E, a disilane gas and a diluted (10%) diborane gas are first supplied to a film-formation chamber at a flow rate of 100 sccm and 20 sccm, respectively, at 300° C. In this manner, an amorphous silicon thin film 250 containing boron is formed over the entire surface of the substrate. Under these film-formation conditions, the concentration of boron contained in the amorphous silicon thin film 250 is 4×10 20 atoms/cm 3 . The resistance of the amorphous silicon thin film 250 decreases. At that time, if the film thickness of the amorphous silicon thin film 250 is set to 1/2 of the opening width of the opening 249 on the source/drain region, the opening 249 can be filled completely.
As shown in FIG. 5F, when the amorphous silicon thin film 250 is polished by the CMP method to the height of the gate portion, the amorphous silicon thin film 250 is separated on the gate portion. As a result, the amorphous silicon thin film 250 is allowed to remain selectively in the opening 249.
As the polishing agent, for example, an alkali colloidal silica maintained at pH 10-11 is used.
Consequently, the thick and highly-doped source/drain layer 250 made of an amorphous silicon thin film, that is, the low resistance source/drain layer 250 is formed. Therefore, according to this embodiment, the silicide formation step can be omitted.
To crystallize the source/drain layer 250, a heat treatment is performed in a nitrogen atmosphere for 2 hours at 600° C. Different from Embodiments 2 and 3, no silicide film is formed on the upper surface of the source/drain layer 250 for reducing the resistance of the source/drain diffusion layer. However, the boron concentration of the source/drain layer 250 is high, and the transistor can be operated at a satisfactory rate.
As shown in FIG. 5G, after a silicon oxide film 248b (about 300 nm) is deposited over the entire surface of the substrate by the CVD method using TEOS, a contact hole is formed on the source/drain layer 250 by use of a patterned resist mask (not shown). Subsequently, an aluminium film (800 nm) containing silicon and copper in an amount of 0.5% for each is formed and patterned, to form a source/drain electrode 253. Thereafter, heat treatment is performed in a nitrogen atmosphere containing hydrogen (10%) for 15 minutes at 450° C.
FIG. 6 is a diagram showing the relationship between the junction depth and the sheet resistance in the source/drain layer (boron-doped silicon thin film) formed in accordance with the present invention and in the diffusion layer formed by a conventional ion-implantation method.
As is apparent from FIG. 6, according to this embodiment, a source/drain diffusion layer can be formed with a lower sheet resistance than the conventional one. This is because the boron containing silicon thin film used in the source/drain diffusion layer of the present invention is a solid-phase growing film from the amorphous silicon thin film. Hence, a dopant is contained in a high concentration and the dopant profile shows a steep curve.
According to this embodiment, since the depth of the source/drain layer can be controlled by etching the boron-doped silicon thin layer, a shallow source/drain layer of 100 nm or less can be easily formed. Besides this, the same effects as those of Embodiment 2 can be obtained. In Embodiments 2 to 4, an MOS transistor is formed on a flat substrate since an element isolation film and an element region are formed with the same height. The MOS transistor can be formed on a substrate having a stepped portion resulting from the element isolation film being higher than that of the element region.
FIGS. 7A-7H show the steps of manufacturing an MOS transistor on a substrate having a stepped portion in Embodiment 3. The like reference numerals designate like structural elements corresponding to those shown in FIGS. 4A-4H.
In FIG. 7A, a silicon nitride film 226 of the gate portion may be formed in a thickness equal to or thicker than the difference in height between an element isolation film and an element region in Embodiment 3. Thereafter, the same steps as those of Embodiment 3 may be repeated. When the substrate having a stepped portion on the surface is used in the cases of Embodiments 2 and 4, the same procedure as that in this embodiment may be employed.
In Embodiments 2 to 4 as well as in other Embodiments, a general silicon substrate is used as a semiconductor substrate. An SOI (silicon on insulator) substrate formed by the SIMOX (separation by implanted oxygen) method may be used.
In Embodiments 2 to 4, the exposed silicon surface of the source/drain region is etched by use of activated CF 4 with a microwave discharge. Instead of CF 4 , other halogen series material, such as F 2 , Cl 2 , SF 6 , HF, ClF 3 or the like may be used.
In Embodiments 2 to 4, a mixed gas of a disilane gas and a diborane gas is used as a material gas of the thin silicon film. The gas is not limited in types. Examples of an applicable gases include silane (SiH 4 ), dichlorsilane (SiH 2 Cl 2 ), SiCl 4 , SiF 4 , SiR 2 H 4 Cl 2 , SiH 2 F 2 , Si 2 H 2 Cl 4 , Si 2 C1 6 , Si 2 H 4 F 2 and Si 2 F 6 .
When an impurity-doped thin silicon film is formed, boron trichloride (BCl 3 ) or boron trifluoride (BF 3 ) other than a diborane may be added to the aforementioned gas in the case of a p-type MOS transistor. Phosphine (PH 3 ), arsine (AsH 3 ) or a halogenated compound containing phosphorus or arsenic may be added to the aforementioned gas in the case of an n-type MOS transistor.
(Embodiment 5)
FIGS. 8A and 8B are cross sectional views of an MOS transistor, showing the steps of manufacturing the MOS transistor according to Embodinent 5 of the present invention. In the transistor of this Embodiment, the upper surface of the gate portion is formed in the same plane as the upper portion of the source/drain diffusion layer.
As shown in FIG. 8A, a gate portion is formed on a silicon substrate 301 in the element formation region defined by the element isolation film 302. Thereafter, the surface of the substrate of the source/drain region is etched and then a doping film 307 is formed over the entire surface.
In FIG. 8A, reference numeral 303 indicates a gate electrode formed of polysilicon and reference numeral 304 denotes a gate insulation film, a side-wall gate insulation film, and an upper gate insulation film. The gate electrode 303 is formed by using a resist mask with the gate length set in the lowermost dimensions. The doping film 307 is a silicon film to which phosphorus, boron or arsenic is doped by a CVD method. The doping film 307 may be formed of silicide which is an alloy formed from silicon and a refractory metal such as tungsten or titanium.
When the source/drain layer is formed by etching the doping film 307 using a resist mask, the source/drain layer cannot be formed accurately in position since the gate electrode 303 is formed also on the gate electrode 303. This is because a masking error occurs since the resist mask formed in the lowermost dimensions is used.
Then, the doping film 307 is polished to remove the doping film 307 on the gate electrode, as shown in FIG. 8B. In this manner, the doping film 307 is allowed to remain selectively in two source/drain regions. As a result, the source/drain diffusion regions 305 and 306 are formed accurately in position. The method of separating the source/drain diffusion layer 305 or 306 from the adjacent region will be described later.
(Embodiment 6)
FIGS. 9A-9D are cross-sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 6 of the present invention. In the transistor of this Embodiment, the upper surface of the gate portion is formed in the same plane as that of the source/drain diffusion layer.
FIG. 9A is a cross sectional view of the MOS transistor after completion of the gate portion formation step. As the element isolation film 312, a buried oxidation film is used. The buried oxidation film is formed by etching the element isolation region of the silicon substrate 311 by means of anisotropic ion etching, depositing the oxide film by means of the CVD method using TEOS, and polishing and flattening the surface of the substrate.
After completion of the element isolation film 312, a gate oxidation film 314 is formed by thermal oxidation at 950° C. in an oxygen atmosphere. Subsequently, a polycrystalline silicon film, which will be a gate electrode 313, is deposited at 620° C. by the CVD method using a silane gas. After phosphorus is introduced into the polycrystalline silicon by phosphorus diffusion, the phosphorus-doped silicon is patterned by use of a resist mask, thereby forming a gate electrode 313. Usually, a silicon nitride film is deposited on the polycrystalline silicon film prior to patterning.
After formation of the gate electrode 313, a silicon oxide film is deposited over the entire surface in a thickness equal to or more than the thickness of the gate portion. The entire surface of the resultant structure is subjected to anisotropic ion etching, to form a silicon oxide film selectively on the side-wall of the gate portion. The silicon oxide film and the silicon nitride film of the side wall of the gate portion are indicated by the same reference number 314 as that of the gate oxide film.
FIG. 9B is a cross sectional view of the MOS transistor immediately after the silicon substrate 311 of the source/drain region is etched. The etching is performed by a so-called chemical dry etching method using activated CF 4 gas by means of RF discharge or by an etching method using a CIF 3 gas. Any etching method may be used as long as the silicon substrate 311 is selectively etched without the oxide film being etched. However, an isotropical etching method is; preferably used.
FIG. 9C is a cross sectional view, of the MOS transistor immediately after the doping film 317 is deposited over the entire surface of the substrate. The doping film 317 is formed by the CVD method using a disilane gas or a diborane gas at 350° C. When an n-channel MOS transistor is formed, the doping film 317 containing phosphorus or As is formed.
FIG. 9D is a cross sectional view of the MOS transistor at the time the source/drain layers 315 and 316 are formed by polishing the doping film 317 in the same manner as in Embodiment 5. The doping film 317 is polished with a polishing agent, alkali colloidal silica, at pH 10-11. The polishing rate of the polycrystalline silicon is 0.5 μm/minute. The polishing rate of the silicon oxide (SiO 2 ) is 1/100 or less of that of the polycrystalline silicon. The polishing rate of the silicon nitride is considerably lower than that of the polycrystalline silicon. Hence, when the insulation film 314 on the gate electrode is exposed, the polishing does not proceed any more.
(Embodiment 7)
FIGS. 10A-10E are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 7 of the present invention. In this embodiment, two MOS transistors are connected by way of a shared source and drain. The upper surfaces of the gate portions are formed in the same plane as those of the source/drain diffusion layers.
The gate oxide film is formed by thermal oxidation. As the gate electrode 323, a polycrystalline silicon film is used which is formed by use of a silane gas at 620° C. The gate oxidation film is preferably formed in accordance with a conventional element formation process, for example, by performing pseudo oxidation prior to the formation of the gate oxidation film.
As shown in FIG. 10A, on a silicon substrate 321 having an element isolation film 322 and a gate portion are formed therein and on, respectively, an insulation film 324 is deposited over the entire surface. The same effects of the present invention by using obtained by using either an oxide film or a nitride film as the insulation film 324. It is preferable that the gate processing be performed after a silicon nitride film 329 is deposited on the gate electrode 323, since the gate electrode 323 will be protected in a later processing step.
As shown in FIG. 10B, the entire surface is etched by use of the RIE method to form an insulation film 324 selectively on the side wall of the gate electrode 323. Thereafter, the source/drain region may be formed by introducing an impurity B, As or P into the source/drain region and activating the impurity by heat treatment at 850° C. However, this embodiment does not employ such a method but employs a doping film as is the same as in the previous embodiment to render the junction region shallow.
As shown in FIG. 10C, the source/drain region of the silicon substrate 321 is etched. As shown in FIG. 10D, a doping film 327 is formed over the entire surface by the CVD method using a diborane and disilane gas at 350° C. In place of the CVD method, a film-formation method such as a sputtering method or a UHV (ultra high vacuum) deposition method may be used. In this case, if the doping film 327 is amorphous, the doping film 327 may be crystallized by treating with heat for 2 hours at 600° C. in a nitrogen atmosphere. The temperature and the time of the heat treatment may be higher and shorter than those mentioned above as long as they do not have effects on the other steps. When the heat treatment is performed at a temperature lower than 600° C., if the heat treatment is performed for a longer time, the crystallization can be effected.
Finally, as shown in FIG. 10E, the doping film 327 on the gate portion is removed by polishing with a polishing agent, alkali colloidal silica, to form source/drain layers 325 and 326. According to the self alignment method mentioned above, the source/drain layer can be formed in the lowermost dimensions as the same as the gate electrode. As a result, integration density can be increased and the resistance and electric capacitance can be reduced between the source and the drain.
The delay time of the CMOS ring oscillator formed of the elements of this embodiment is 15 psec/stage. The delay time of the CMOS ring oscillator formed of conventional elements in accordance with 0.2 μm rule is 30 psec/stage. This fact demonstrates the effect of the present invention in reducing the resistance and electric capacitance between the source and the drain.
As the element isolation method, which is omitted in the above mentioned steps, a general LOCOS element isolation method may be employed. Instead of using the doping film, an impurity such as B, As, or P may be doped in the semiconductor substrate of the source/drain layer, and thereafter, a conductive film such as a metal film and an alloy film may be formed.
(Embodiment 8)
FIGS. 11A-11E are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 8 of the present invention. This embodiment is the same as Embodiment 7 except that two MOS transistors are isolated.
As shown in FIG. 11A, on the silicon substrate 331 with an element isolation film 332 and the gate portion formed therein and on, respectively, an SiO 2 film 334 and a resist mask 338 are sequentially formed. It is preferred that an insulation film such as a silicon nitride film 339 be formed on the gate electrode 333, as shown in the figure. The SiO 2 film 334 is formed in the same thickness of that of the gate portion by the CVD method using TEOS and ozone. The resist mask 338 is formed at a desired isolation region. When the element isolation film 332 is formed with the same height as that of the gate portion, the same effect can be obtained although a circuit design will be limited.
As shown in FIG. 11B, the entire surface is etched by the anisotropic etching . As a result, a SiO 2 film 334 is allowed to remain selectively on the side-wall of the gate portion and at only the lower portion of the resist mask 338.
As shown in FIG. 11C, the source/drain region of the silicon substrate 331 is etched by the chemical dry etching method attaining selective silicon etching. When the gate length is 0.1 μm, the etching depth is set to about 0.03 μm. This embodiment employs etching, however, implantation of impurity ions (As, P, or B) into the source/drain region may be employed.
As shown in FIG. 1D, after a doping film 337 is formed of amorphous silicon by the CVD method using a diborane gas and a disilane gas at 350° C., heat treatment is performed at 600° C. for 2 hours in a nitrogen atmosphere, thereby obtaining a single-crystalline film. In this embodiment, the doping film containing boron is used. However, use may be made of another doping film formed of a silicon film containing an impurity other than boron. Furthermore, instead of the doping film, an impurity (B, As, or P) may be implanted in the semiconductor substrate of the source/drain layer, and thereafter a conductive film such as a metal film or an alloy film may be formed thereon.
Finally, as shown in FIG. 11E, the doping film 337 on the gate electrode 333 is removed by polishing with a polishing agent, alkali colloidal silica. As a result, source/drain layers 335 and 336 are formed.
In this manner, an MOS transistor can be obtained not only with a gate length of 0.1 μm and a junction depth of 0.03 μm but also with the source/drain layers 335 and 336 obtained by processing the doping film in the same lowermost dimensions as the gate electrode. Each of MOS transistors is separated by a micro-processing technique with the same accuracy as that of the gate. As a result, an individual element region can be reduced to the limit attained by the micro-processing technique.
(Embodiment 9)
FIGS. 12A-12E are cross-sectional views of a MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 9 of the present invention. In the same as in Embodiment 8, two MOS transistors of this embodiment are not in contact with each other.
A feature different from Embodiment 8 resides in that a gate electrode (pseudo gate electrode) is formed also in the region to be isolated by use of the same mask at the time the gate electrode is formed. In this manner, not only the miniaturization of the gate electrode but also the miniaturization of the source/drain layer can be attained without misalignment.
As shown in FIG. 12A, on a silicon substrate 341 with an element isolation film 342 and the gate portion formed therein and on, respectively, an SiO 2 film 344 is formed. It is preferred that an insulation film such as a silicon nitride film 349 be formed on the gate electrode 343 as shown in the figure. The gate length on the gate electrode 343 is formed in the lowermost dimensions. The gate electrode 343 may be formed also on an element isolation film 342. To be more precisely, this gate electrode 343 (pseudo gate electrode 343) is inevitably formed at the same time the gate electrode of each MOS transistor is formed. Therefore, the pseudo gate electrode does not have the function as the gate electrode.
As shown in FIG. 12B, the SiO 2 film 344 is left selectively on the side wall of the gate portion. Thereafter, as shown in FIG. 12C, the source/drain region of the silicon substrate 341 is selectively etched by the chemical dry etching. Instead of etching the substrate, impurity ions (As, P, or B) may be implanted in the substrate surface to form the source/drain region.
As shown FIG. 12D, a doping film 347 is deposited over the entire surface. Subsequently, as shown in FIG. 12E, the protruding portion of the doping film 347 is polished and the surface thereof is flattened. In this case, the gate electrode 344 on the element isolation film 342 is covered with an insulation film, so that doping films 345 and 346 on either side are is electrically isolated. Through this step, MOS transistors are separated into two.
(Embodiment 10)
FIGS. 13A-13Q are cross sectional views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 10 of the present invention. In this embodiment, two or more transistor source/drain regions of are simultaneously formed.
As shown in FIG. 13A, an SiO 2 film 354 is formed on a silicon substrate 351 with an element isolation film 352 and the gate portion of a first MOS transistor formed therein and on, respectively. It is preferred that an insulation film such as a silicon nitride film 359 be formed on the gate electrode 353.
As shown in FIG. 13B, an insulation film 354 is formed selectively on the side wall of the gate electrode 353 by anisotropic etching. Thereafter, as shown in FIG. 13C, after a gate oxidation film 361 of a second MOS transistor is formed, the second MOS transistor formation region is covered with a resist 360. Before the gate oxidation film 361 is formed, generally-performed pseudo oxidation may be carried out.
As shown in FIG. 13D, after the gate oxidation film 361 of the first MOS transistor region is selectively removed by the RIE method or with a hydrofluoric acid or an aqueous solution of ammonium fluoride, the resist 360 is removed. Subsequently, as shown in FIG. 13E, the source/drain region of the first MOS transistor of the silicon substrate 351 is removed by etching. Instead of etching removal of the source/drain region, impurity ions(P, As or B) may be implanted in the substrate surface of the source/drain region. In the case of ion implantation, it is better to employ a method of injecting ions before the resist 360 is removed in the step shown in FIG. 13D, because this method can prevent the ions from being implanted into the portion under the gate oxidation film of the second MOS transistor.
As shown in FIG. 13F, a doping film 367 is formed over the entire surface. As the doping film 367, use may be made of a silicon film doped with boron (p-type impurity), arsenic (n-type impurity), or phosphorus (n-type impurity) by the CVD method. In the case where a source/drain region is formed by impurity-ion implantation in the substrate surface, a conductive film may be used in place of the doping film.
As shown in FIG. 13G, the doping film 367 on the gate portion is removed by polishing. Subsequently, as shown in FIG. 13H, a resist mask 360 covering the first MOS transistor and a resist mask 360 covering the gate portion of the second MOS transistor are formed. The resist mask 360 must be cut on the element isolation film 352, no matter where on the film 352, so that a problem of misalignment will not take place.
As shown in FIG. 13I, the doping film 357 is etched by the anisotropic etching with the resist mask 360 as a mask. As a result, source/drain layers 355 and 356 of a first MOS transistor and the gate electrode 363 of the second MOS transistor are formed. At this time, the etching may be stopped by the gate oxide film 361 used as an etching stopper or may be continued until the gate oxide film 361 is removed.
As shown in FIG. 13J, an insulation film 354 is formed over the entire surface. Subsequently, as shown in FIG. 13K, the entire surface of the insulation film 354 is etched by the anisotropic etching. As a result, the insulation film 354 is selectively left on the side wall of the gate portion of a second MOS transistor and on the side wall of the source/drain layer 356 of the first MOS transistor.
As shown in FIG. 13L, an insulation film 358 is formed over the entire surface. The insulation film 358 is used as a stopper during a polishing step (FIG. 13Q) performed later. Then, as shown in FIG. 13K, the resist 360 is formed on the first MOS transistor formation region. The resist must be cut on the element isolation film 352 no matter where on the film 352, so that a misalignment problem will not take place.
As shown in FIG. 13N, an insulation film 358 on the second MOS transistor region is removed by the reactive ion etching, chemical dry etching, or wet etching using hydrofluoric acid series aqueous solution, by use of the resist 360 as a mask, and thereafter, the resist 360 is removed.
As shown in FIG. 130, the source/drain region of the second MOS transistor on the silicon substrate 351 is etched by means of chemical dry etching or the like. Instead of etching the source/drain region, an impurity (P, As, or B) may be implanted in the substrate surface of the source/drain region.
As shown in FIG. 13P, the doping film 357 is formed over the entire surface. As the doping film 357, it is preferable to use a silicon film doped with boron (p-type impurity), arsenic (n-type impurity), or phosphorus (n-type impurity) by the CVID method. When the source/drain region is formed by implanting impurity ions in the substrate surface, a conductive film may be used in place of the doping film.
As shown in FIG. 13Q, the doping film 357 on the gate portions of the first and second MOS transistors is removed by polishing. As a result, the source/drain layers 355 and 356 of the second MOS transistor are formed, at the same time, the first and the second MOS transistors are electrically isolated from each other.
In the aforementioned method, to connect the source/drain layer 356 of the first MOS transistor to the gate electrode 363 of the second MOS transistor, an interlayer insulation film is further required with a contact hole provided therein. By way of an aluminium electrode or the like, the source/drain layer 356 is connected to the gate electrode 363.
To connect the source/drain layer 356 to the gate electrode 363 without the use of the interlayer insulation film, contact hole, and aluminium electrode, use may be preferably made of the resist 360 having a pattern shown in FIG. 14A, in other words, the resist 360 extending over the doping film 357 of the second MOS transistor, instead of the resist 360 having a pattern shown in FIG, 13H. In this manner, it is possible to form an element structure having the source/drain layer 356 of the first MOS transistor connected to the gate electrode 363 of the second MOS transistor.
In the case of an SRAM using a CMOS inverter characterized by the structure having a drain of an MOS transistor connected to a gate of another MOS transistor, the manufacturing steps can be shortened and simplified by employing the method shown in FIGS. 14A and 14B. It should be noted, in FIGS. 14A and 14B, that the cross sectional view of the first MOS transistor positioned on the left-hand side is parallel to the channel, whereas, the cross sectional view of the second MOS transistor positioned on the right-hand side is perpendicular to the channel. That is, in the transistor positioned on the right-hand side, the source/drain layer is positioned in the perpendicular direction to the face of the paper.
(Embodiment 11)
FIGS. 15A-15L are cross sectional views of a CMOS transistor, sequentially showing the steps of manufacturing the CMOS transistor according to Embodiment 11 of the present invention.
As shown in FIG. 15A, a gate portion 373 of an n-channel MOS transistor consisting of a gate insulation film and a gate electrode (polysilicon), is formed on a silicon substrate 371 with an element isolation film 372 formed therein. Before elements are isolated in accordance with a general MOS process, that is, before the gate oxidation film is formed, a pseudo oxidation film or a nitride film (not shown) is formed. In this embodiment, the steps of forming an n-channel MOS transistor in the first place, will be described, however, a p-channel MOS transistor may be formed first.
As shown in FIG. 15B, a silicon oxide film 374 is formed in a thickness equal to or larger than that of the gate portion 373. Thereafter, as shown in FIG. 15C a resist 375 is formed in a p-channel MOS transistor formation region.
As shown in FIG. 15D, the entire surface of the silicon oxide film 374 is etched by the RIE method using the resist 375 as a mask. A si icon oxide film 374 is left selectively on the side wall and the upper surface of the gate portion 373 and the lower portion of the resist 375.
As shown in FIG. 15E, the surface of the silicon substrate 371 of the source/drain region of the n-channel MOS transistor is etched. Instead of etching the source/drain region, phosphorus or arsenic ions may be implanted in the substrate surface of the source/drain region.
As shown in FIG. 15F, a doping film 378, which is a phosphorus-doped or arsenic-doped amorphous state or a polycrystalline state silicon film, is formed over the entire surface. When the amorphous state doping film is used, heating may be simultaneously applied to the doping film to crystallize it.
As shown in FIG. 15G, the silicon oxide film 374 and the doping film 378 on the gate portion are removed by polishing to form the source/drain diffusion layers 379 and 380. Subsequently, as shown in FIG. 15H, a silicon oxide film 381 is formed over the entire substrate surface, a resist 382 is formed on the n-channel MOS transistor region. Using the resist 382 as a mask, the silicon oxide film 374 of a pMOS transistor is removed by etching. At this point, the silicon oxide film 374 remains on the side wall of the source/drain diffusion layer 380. This is because the resist 382 is also present above the outer side of the side wall of the source/drain diffusion layer 380.
As shown in FIG. 15I, after a gate insulation film (not shown) of the p-channel MOS transistor is formed, a semiconductor film or a conductive film 383, which will serve as the gate electrode of the p-channel MOS transistor, is formed over the entire surface. Thereafter, the resist 382 is formed on the gate insulation film corresponding to the gate region of the p-channel MOS transistor.
As shown in FIG. 15J, the semiconductor film or the conductive film 383 is etched by the RIE method using the resist 382 as a mask. Consequently, a gate electrode 383 of the p-channel MOS transistor is formed. It is preferable that a silicon nitride film be formed on the gate electrode 383.
As shown in FIG. 15K, a silicon oxide film 384 is formed over the entire surface in a thickness equal to or more than that of the gate portion (consisting of a gate insulation film (not shown) and a gate electrode 383. Subsequently, as shown in FIG. 15L, the entire surface of the silicon oxide film 384 is etched by means of the RIE method. Consequently, the silicon oxide film 384 is selectively left on the side wall of the gate portion.
Then, a doping film is formed in the same manner as shown in FIGS. 15E-15G to form a source/drain layer, thereby forming a p-channel MOS transistor. The doping film used herein contains p-type impurity such as boron. The impurity may be doped either simultaneously with or after the film formation.
(Embodiment 12)
FIGS. 16A-16D are plan views of en MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 12 of the present invention. In this embodiment, the upper surface of the gate electrode and the surface of the source/drain electrode are formed in the same plane and the source/drain electrode is formed next to the gate electrode in the self-alignment manner.
First, a silicon substrate 402 is prepared with an insulation film 401 formed over the entire surface. Then, the insulation film 401 of the source/drain region is removed as shown in FIG. 16A to expose the surface of the silicon substrate 402.
As shown in FIG. 16B, after a semiconductor film or a conductive film serving as a gate electrode 403 is deposited over the entire surface, the semiconductor film or conductive film are processed by use of a miniaturization processing technique. Consequently, a gate electrode 403 is formed surrounding the surface region 402 of the substrate, which will serve as source/drain region. When the source/drain region is connected to the source/drain region or the gate electrode of another element, it is better to remove part of the gate electrode 403 surrourding the source/drain so as to obtain the cross section shown in Embodiments 5 or 8.
As shown in FIG. 16C, an insulation film which will be the side-wall gate insulation film 404 is deposited over the entire surface in a thickness equal to or more than that of the gate electrode 403. After the entire surface of the insulation film is etched by anisotropic etching to remove the insulation film except for the side wall of the gate electrode 403, a side-wall gate insulation film 404 is formed. Note that the insulation film may be left on the gate electrode 403.
As shown in FIG. 16D, after a semiconductor film and a conductive film which will be the source/drain layer 407 is deposited over the entire surface, the semiconductor film or the conductive film on the gate electrode 403 is removed by polishing.
As a result, two source/drain electrodes 407 are formed next to the gate electrode 403 in a self-alignment manner with the side-wall insulation film 404 interposed therein. The two source/drain electrodes 407 are electrically isolated to each other. The semiconductor film or conductive film which remains on the outer region of the gate electrode 403, is electrically isolated from the source/drain electrode 407.
(Embodiment 13)
FIGS. 17A-17D are plan views of an MOS transistor, sequentially showing the steps of manufacturing the MOS transistor according to Embodiment 13 of the present invention. In this embodiment, the upper surface of the gate electrode and the surface of the source/drain electrode are formed in the same plane by using a general gate pattern, and the source/drain electrode is formed next to the gate electrode in the self-alignment manner.
First, a silicon substrate 412 is prepared with an insulation film 411 formed over the entire surface. Then, the insulation film 411 of the source/drain region is removed (as shown in FIG. 17A) to expose the surface of the silicon substrate 412.
As shown in FIG. 17B, after a semiconductor film or a conductive film, which will serve as a gate electrode 403, is deposited over the entire surface, the semiconductor film or conductive film are processed by use of a miniaturization processing technique. Consequently, a gate electrode 413 having a general pattern is formed.
As shown in FIG. 17C, an insulation film which will serve as the side-wall gate insulation film 414 is deposited over the entire surface in a thickness equal to or more than that of the gate electrode 413. After the entire surface of the insulation film is etched by the anisotropic etching to remove the insulation film except for the side wall of the gate electrode 413, a side-wall gate insulation film 414 is formed. Note that the insulation film may be left on the gate electrode 413.
As shown in FIG. 17D, after a semiconductor film and a conductive film, which will serve as the source/drain layer 417, are deposited over the entire surface, the semiconductor film or the conductive film on the gate electrode 413 is removed by polishing. As a result, the semiconductor film or conductive film 417 is electrically isolated from the gate electrode 413. Note that the semiconductor film 417 is not divided into two portions in this stage. Afterwards, the semiconductor film or conductive film is separated by forming an isolation layer 418 to form two source/drain layers.
(Embodiment 14)
FIGS. 18A-18C are views for use in explaining an MOS transistor according to Embodiment 14 of the present invention. FIG. 18A is a schematic plan view showing layered mask patterns responsible for the formation of individual regions of the transistor. The cross sectional structure of the MOS transistor can be figured out if FIGS. 18B and 18C are referred to together.
In FIGS. 18A-18C, reference numeral 421 is a silicon substrate in which an element isolation film 422 is buried. After a gate electrode 423a is formed, the portion of the substrate with a semiconductor film buried therein, is polished, thereby forming source/drain layers 425 and 426. The polishing is performed so as to stop at the upper surface of the element isolation film 422 and the upper surface of the gate portion. The source/drain region may be formed by implanting impurity ions into the substrate surface in place of burying the semiconductor film.
In an interlayer insulation film 429, contact holes are provided in which upper-layer, wiring elements 432g, 432s, and 432d are individually buried. In FIGS. 18B and 18C, these upper-layer wiring elements are completely buried in the interlayer insulation film 429, however, they may be formed in a thin-film form. If necessary, the upper wiring element 432 may be left on the interlayer insulation film 429 for example, by mask processing.
As shown in FIG. 18C, insulation Films 420a and 420b present under the gate electrode 423a and the gate wiring 423b differ in thickness. It is preferable that the insulation film 420b of the gate wiring be thicker than the insulation film 420a of the gate electrode. For example, the thickness of the insulation film 420a is set to 5 nm and thickness of the insulation film 420b is set to 100 nm. As the insulation films 420a and 420b, an oxide film and a nitride film are employed.
The gate electrode 423a and the source/drain layers 425, 426 are processed in the lowermost width applicable for LSI manufacturing. The opening width of the wiring groove of the upper-layer wiring 432 may be wider than the lowermost processing width and may include a margin for misalignment.
FIGS. 19A, 19B, 20A, and 20B are views for use in explaining a basic concept for manufacturing the MOS transistor of this embodiment.
In the method shown in FIGS. 19A and 19B, the insulation films 420a are and 420b different in thickness are first formed (FIG. 19A), and then, a gate electrode 423a and a gate wiring 432b are formed (FIG. 19B).
In the method shown in FIGS. 20A and 20B, the thicker 420b is formed over the entire surface, and then the wiring 423b is formed in a gate electrode formation region and in the gate wiring region (FIG. 20A). Afterwards, the gate wiring region is covered with a resist mask 430 and the wiring 423b and the insulation film 420b are removed by etching, thereby forming a thin insulation film 420a and the gate electrode 423a.
FIGS. 21A-21C show a method of lowering variations in gate length due to misalignment between the gate electrode and the mask for the source,drain formation.
As shown in FIG. 21A, an element isolation film 422, a gate electrode 423a', and a gate wiring 423b are formed on a silicon substrate. The portion of the gate electrode 423a' connecting to the gate wiring 432b is formed in the form of a taper with an angle of 45° . In this stage, a desired gate electrode has not yet been made.
As shown in FIG. 21B, a resist mask 430 for use in forming the source/drain region, is formed on the substrate.
As shown in FIG. 21C, the exposed portion of the gate electrode 423a' is etched by use of a resist mask 430. As a result, the silicon substrate is exposed. Since the portion of the gate electrode 423a' connecting to the gate wiring 423b is formed in the form of a taper, there is small variation in the gate length even if the resist mask 430 shifts in the lateral direction. In this step, the desired gate electrode 423a is made.
FIGS. 22A-22U are plan views of the transistor, sequentially showing the details of the method shown in FIGS. 19A and 19B.
As show in FIG. 22A, a gate insulation film 420b is formed on a silicon substrate (not shown) in a thickness of 100 nm by the CVD method, the thermal oxidation method, or the like.
As shown in FIG. 22B, a resist mask 430 is formed on the insulation film 420b of the gate wiring region. Subsequently, as shown in FIG. 22C, the insulation film 420b of the gate electrode region is removed by the RIE, CDE, wet etching using an HF solution or the like using the resist mask 430. As a result, the surface of the substrate 421 of the gate electrode region is exposed.
As shown in FIG. 22D, the resist mask 430 is then removed by an asher or SH treatment (treatment with a mixed solution of sulfuric acid and hydrogen peroxide). Thereafter, as shown in FIG. 22E, the gate insulation film 420a is formed on the substrate 421 through the oxidation in an oxygen atmosphere for 30 minutes at 950° C.
As shown in FIG. 22F, a conductive thin film 423 is formed which consists of a semiconductor thin film or a metal thin film which will be a gate electrode 423a and a gate wiring 423b. It is better to remove the stepped portion formed on the thin film by polishing. It is preferable that an insulation film such as a nitride film be formed on the thin film.
As shown in FIG. 22G, a resist mask 430 is formed so as to cover the MOS transistor formation region. Subsequently, as shown in FIG. 22H, the conductive thin film 423 not covered with the resist 430 is removed by the anisotropic etching, to expose the gate insulation films 420b and 420a.
After the surface of the substrate 421 is exposed by etching the gate insulation films 420a and 420b, the substrate 421 is further etched to the depth required for element isolation. In this manner, a depressed portion is formed. Then, the resist 430 is removed as shown in FIG. 22J.
As shown in FIG. 22K, an insulation film 422 serving as an element isolation film, is deposited over the entire surface. For example, in the case where the etching amount (depth) of the substrate is 2 μm, the thickness of the gate insulation film is 100 nm, and the thickness of the conductive thin film 423 is 400 nm, an oxide film serving as the insulation film 422 is formed in a thickness of 2.5 μm or more from TEOS (tetraethylorthosilicate).
As shown in FIG. 22L, the insulation film 422 on the conductive thin film 423 is removed by polishing. As a result, the insulation film 422 is allowed to remain selectively in the depressed portion formed in the substrate surface by etching. In this manner, a buried element isolation film 422 is formed.
As shown in FIG. 22M, the conductive thin film 423 and the gate oxide film 420a are removed by use of the resist mask 430. The etching may be stopped at the time the gate oxide film 420a is exposed and the gate oxide film 420a is removed by another etching using e.g. HF.
When the source/drain or the gate of another MOS transistor (not shown) is connected to the source/drain or the gate of the transistor mentioned above, the conductive thin film serving as wiring may be left, as shown in Embodiments 7 and 8.
As shown in FIG. 22N, after the resist mask 430 is removed, the conductive thin film 423 is etched until the substrate 421 of the source/drain layers 425 and 426 formation region is exposed, thereby forming the gate electrode 423a and the gate wiring 423b.
As shown in FIG. 220, an insulation film 428 is formed over the entire film. Thereafter, as shown in FIG. 22P, the entire surface of the insulation film 428 is etched by anisotropic etching to form a side-wall gate insulation film 428s. Then, the substrate 421 of the source/drain region is etched to the depth where a PN junction is to be formed.
As shown in FIG. 22Q, an impurity-doped semiconductor film 427 is deposited over the entire surface. Subsequently, as shown in FIG. 22R, the semiconductor film 427 on the element isolation film 422, on the gate electrode 423a and on the gate wiring 423b is removed. The semiconductor film 427 remaining in the source/drain region will serve as the source layer 425 and the drain layer 426.
As shown in FIG. 22S, an insulation film 429 is deposited over the entire surface. Thereafter, a resist mask 430 is formed as shown in FIG. 22T. Then, a contact hole 433 is formed by the RIE method. The contact hole 433 is required for connecting the source/drain layers 425, 426 to the upper layer wiring 432 and connecting the gate electrode 423 and the upper-layer wiring 432. The contact hole 433 is arranged in a different position from the gate wiring 423b to avoid a short circuit due to misalignment.
Finally, as shown in FIG. 22U, after the resist mask 430 is removed, the upper-layer wiring 432 is formed of aluminium or the like, and then, the gate contact 432g, source contact 432s, drain contact 432d are formed. In FIG. 22U, only the insulation film 429 should be seen except for the upper wiring 432, however, FIG. 22U shows the construction uncovered with the insulation film 429 for facilitating understanding.
In the aforementioned manufacturing method, the substrate surface is etched to form a depressed portion in the stage shown in FIG. 22M and an impurity containing semiconductor film is buried in the depressed portion to form a source/drain layer. In this case, the source/drain layer may be formed by injecting impurity ions to the substrate surface instead of etching it. In the case of ion implantation, a metal film may be used as the conductive layer 427 to be buried in the source/drain region in the stage of FIG. 22R.
FIGS. 23A-23X are plan views of a transistor, sequentially showing the details of the method explained in FIGS. 20A and 20B.
As shown in FIG. 23A, the thicker gate insulation film 420b (e.g., 100 nm) is formed on a silicon substrate (not shown) by means of the CVD method, the thermal oxidation method, or the like. Thereafter, as shown in FIG. 23B, a conductive thin film 423 (which is made of semiconductor thin film or metal thin film) is formed on the insulation film 420b.
As shown in FIG. 23C, the resist mask 430 is formed in the MOS transistor formation region. Subsequently, as shown in FIG.23D, the conductive thin film 423 except for the MOS transistor formation region is etched by the anisotropic etching using the resist mask 430 as a mask. As a result, gate insulation film 420b is exposed.
As shown in FIG. 23E, the insulation film 420b is etched by using the resist mask 430 as a mask to expose the substrate 421. Thereafter, the substrate 421 is further etched to a depth required for a depressed portion of an element isolation groove. Then, as shown in FIG. 23F, the resist mask 430 is removed to form a conductive thin film 423b' which will serve as a gate wiring.
As shown in FIG. 23G, the insulation film 422 serving as a buried element isolation film is deposited over the entire surface. If the etching amount (depth) of the substrate 421 is 2 μm, the thickness of the thick insulation film 420b is 0.5 μm, and the thickness of the conductive thin film 423b' is 0.5 μm, an oxide film serving as the insulation film 422 (3 it m or more) is formed by depositing TEOS (tetraethylorthosilicate) and buried in the depressed portion. Subsequently, as shown in FIG. 23H, the insulation film 422 on the conductive thin film 423b' is removed by polishing the entire surface. Consequently, the buried element isolation film 422 whose surface is present in the same plane as the conductive thin film is formed 423b'.
As shown in FIG. 23I, the resist mask 430 is formed in a wiring formation region which will be the gate wiring 423b. Subsequently, as shown in FIG. 23J, the conductive thin film 423b' of the wiring formation region, which will be the gate wiring 423a, is removed by anisotropic etching, CDE or the like. As a result, the substrate 421 is exposed as shown in FIG. 23K. Thereafter, the resist mask 430 is removed by an asher or SH treatment (treatment with a mixed solution of sulfuric acid and hydrogen peroxide) as shown in FIG. 23L. The gate wiring 423B is provided in this step.
As shown in FIG. 23M, the gate oxide film 420a is formed on the substrate 421 which has been exposed by oxidation in an oxygen atmosphere for 30 minutes at 950° C. Subsequently, as shown in FIG. 23N, the conductive thin film 423', which will be the gate electrode, is deposited over the entire surface. It is preferred that an insulation film such as a nitride film be formed on the conductive thin film 423'.
As shown in FIG. 230, the conductive thin film 423' on the element isolation film 422 is removed by polishing. Thereafter, as shown in FIG. 23P, the conductive thin film 423' on the source/drain layer formation region is removed by using a resist mask 430. Consequently, the gate electrode 423a is formed. In this case, the etching may be stopped at the stage in which a gate oxide film 420a is exposed and the gate oxide film 420a may be removed by another etching using e.g. HF.
When the source/drain or the gate of another MOS transistor (not shown) is connected to the source/drain or the gate of the transistor mentioned above, the semiconductor film or the conductive film serving as wiring may be left as shown in Embodiments 7 and 8.
As shown in FIG. 23Q, the resist mask 430 is removed and the conductive thin film 423' is etched until the substrate 421 of the source/drain layer formation region is exposed.
As shown in FIG. 23R, the insulation film 428 is deposited over the entire surface. Subsequently, as shown in FIG. 23S, the entire surface of the insulation film 428 is etched by anisotropic etching, to form the side wall gate insulation film 428s. Thereafter, the substrate of the source/drain formation region is etched to the depth where a PN junction is formed.
As shown in FIG. 23T, the semiconductor film 427 is formed over the entire surface. Subsequently, as shown in FIG. 23U, the semiconductor film 427 on the element isolation film 422 and the gate electrode 423 is removed by polishing. As a result, the source/drain layers 425 and 426 are formed.
As shown in FIG. 23V, the insulation film 429 is formed over the entire substrate. Thereafter, as shown in FIG. 23W, a resist mask 430 is formed. Then, contact holes 433s and 433d required for the connection between the source/drain layers 425, 426 and the upper-layer wiring and contact hole 433g required for the connection between the gate wiring 423b and the upper layer wiring are formed by the reactive ion etching, or the like. The contact hole 433g for gate contact is arranged in a different position from the gate wiring 423b to avoid a short circuit due to misalignment.
Finally, as shown in FIG. 23X, after the resist mask is removed, the upper layer wiring (contact) made of aluminium or the like is formed, and then, the gate contact 432g, a source contact 432s, and drain contact 432d are formed. In FIG. 23X, only the insulation film 429 is visible except for the aforementioned contact; however, FIG. 23X shows the structure uncovered with insulation film 429 for facilitating the understanding.
In the aforementioned manufacturing method, the substrate surface is etched to form a depressed portion in the stage shown in FIG. 23Q and an impurity-containing semiconductor film is buried in the depressed portion to form a source/drain layer. In this case, the source/drain layer may be formed by injecting impurity ions into the substrate surface instead of etching it. In the case of the ion implantation, a metal film may be used as the conductive layer 427 to be buried in the source/drain region in the stage of FIG. 23T.
The present invention is not limited to the aforementioned embodiments. Although a silicon substrate is used in the embodiments, another semiconductor substrate such as a GaAs substrate may be used. The present invention may be modified in various ways within the scope of the present invention.
As is described above, according to a first aspect of the present invention, a conductive film for reducing the resistance of the source/drain region can be buried by polishing in a self-alignment manner. Since silicon is not consumed in the method of the present invention, unlike the silicide technique, the source/drain layer will not be destroyed even if the junction of the source/drain layer is shallow. Hence, even if the junction of the source/drain layer is shallow, the resistance of the source/drain can be sufficiently reduced by the conductive film of the present invention.
According to a second aspect of the present invention, a semiconductor film or a conductive film formed over the entire surface can be left selectively in an opening (source/drain layer) by polishing in a self-alignment manner. Hence, a semiconductor film or the like can be isolated at the gate portion without fail and a miniaturized source/drain layer can be formed even if the gate length is formed in the lowermost dimensions.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | The semiconductor device comprises a semiconductor substrate having an element region, an element isolation film formed on the semiconductor substrate so as to surround the element region, a gate portion crossing the element region and extending over the semiconductor substrate, the gate portion comprising at least a gate insulation film formed on the semiconcuctor substrate and a gate electrode formed on the gate insulation film, and source/drain regions formed on the surface of the element regions on both sides of the gate portion, wherein an upper surface of the element isolation film is formed in substantially the same plane as an upper surface of the gate portion. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a precursor fiber bundle to be processed into a carbon fiber bundle, a process for producing the precursor fiber bundle, a carbon fiber bundle, and a process for producing the carbon fiber bundle. In more detail, the present invention relates to a precursor fiber bundle to be processed into a carbon fiber bundle, which is low in production cost, excellent in productivity, and which experiences less fiber breakage and fuzz generation, and which can be transformed into a sub-tow having an optimum formation for supplying to a process for producing a carbon fiber bundle. This invention also relates to a process for producing the precursor fiber bundle, to a carbon fiber bundle prepared from the sub-towo, and to a process for producing the carbon fiber bundle.
[0002] Furthermore, the present invention relates to a precursor fiber bundle comprising an acrylic polymer processed into a carbon fiber bundle, a process for producing the same, a carbon fiber bundle obtained from the precursor fiber bundle, and a process for producing the carbon fiber bundle.
[0003] Conventional precursor fiber bundle to be processed into a carbon fiber bundle is made of an acrylic polymer. The fiber bundle filaments may number from 3,000 to 20,000, and have a fineness of from 1,000 denier to 24,000 denier with small occurrences of fiber breakage and fuzz. It has been used for production of carbon fiber bundles having high strength and high modulus.
[0004] The precursor fiber bundle comprising an acrylic polymer processed into a carbon fiber bundle have been widely used as reinforcing fibers for components in the field of aerospace, sports, etc. The conventional carbon fiber bundle has been mainly examined to enhance its strength and the elastic modulus of carbon fibers. Specific items of examination include degree of crystallite orientation and densifying property of the precursor fibers, single filament breakage, fuzz, adhesion between filaments, acceleration of stabilization of the precursor fibers, etc.
[0005] The utilization of carbon fibers is being expanded at a rapid pace into general industrial fields including automobiles, civil engineering, architecture, energy, compounds, etc., and it is advantageous to supply a raw fiber bundle (precursor fiber bundle) to be processed into a carbon fiber bundle as a multifilament having improved strength and elastic modulus, at lower cost, and with increased productivity.
[0006] However, the raw fiber bundle (precursor fiber bundle) intended to be processed into a carbon fiber bundle is actually produced as a multifilament and wound on a drum or bobbin, and supplied in this style to a process for producing a carbon fiber bundle. Due to restrictions in the process of producing the carbon fiber bundle, particularly restriction of thickness (fineness) of the precursor fiber bundle in the stabilizing process, the rate of productivity has been kept remarkably low.
[0007] That is, the precursor fiber bundle comprising an acrylic polymer, processed into a carbon fiber bundle, is heated in an oxidizing atmosphere having a temperature of from 200° C. to 350° C. for stabilizing prior to carbonizing treatment. The stabilization treatment causes oxidization and cyclization, but since it generates heat, the heat stored in the fiber bundle becomes an important factor. If the heat stored in the fiber bundle is excessive, fiber breakage and adhesion between filaments occur. So, the stored heat must be kept low enough to prevent this.
[0008] Accordingly, a precursor fiber bundle having excessive thickness cannot be supplied into the stabilizing furnace. In industrial production the precursor fiber bundle is accordingly restricted in thickness (fineness). The restriction unfortunately keeps productivity low and is an obstacle in reducing production cost.
[0009] Producing a thermoplastic synthetic fiber bundle as a raw fiber bundle to be processed into a spun yarn or a non-woven fabric, not as a precursor fiber bundle to be processed into a carbon fiber bundle, is disclosed in Japanese Patent Laid-Open (Kokai) No. 56-4724. In this process, a tow running into a crimping apparatus is divided by dividing pins located close to the entrance of the crimping apparatus. A plurality of divided sub-tows are simultaneously supplied into the crimping apparatus, so that the plurality of sub-tows may be crimped as a whole, to be collected as one crimped tow capable of being potentially divided into crimped sub-tows later. However, if this process is applied to production of a precursor fiber bundle intended to be processed into a carbon fiber bundle, fiber breakage occurs often. This lowers the grade of the product since it is necessary to divide into a plurality of sub-tows a precursor fiber bundle having a fineness of not less than 300,000 denier in which filaments are engaged with each other by mutual oblique crossing and are closed up each other. This also adversely affects the production of carbon fibers.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide a precursor fiber bundle that can effectively and efficiently to be processed into a carbon fiber bundle which can be larger in thickness, i.e., in fineness to provide high productivity and low production cost, and which can be easily divided into sub-tows, each of which has a thickness (fineness) as required for producing a carbon fiber bundle, considering the restriction of thickness (fineness) of the fiber bundle in the process.
[0011] A further object of the present invention is to provide a process for producing the precursor fiber bundle, and the resulting carbon fiber bundle, and a process for producing the carbon fiber bundle. Hereinafter in this specification, the expression “precursor fiber bundle” means a precursor fiber bundle adapted to be processed into a carbon fiber bundle or a precursor fiber bundle for production of a carbon fiber bundle.
[0012] The precursor fiber bundle of the present invention can be kept in the form of one single tow when packed in a container, and can potentially be divided into a plurality of sub-tows when taken out of its container and used for producing a carbon fiber bundle.
[0013] The precursor fiber bundle of the present invention is an acrylic polymer fiber tow having the total fineness of about 300,000 denier to 1,500,000 denier, and preferably having a number of filaments of from about 50,000 to about 1,000,000, which can be potentially divided into sub-tows each of which has a fineness of from about 50,000 denier to about 250,000 denier.
[0014] The precursor fiber bundle may also be a crimped tow or a non-crimped tow. In the case of a non-crimped tow, its moisture content is preferably in the range of from about 10% to about 50%.
[0015] Furthermore, the degree of entanglement of each of the sub-tows divided from the precursor fiber bundle is preferably in the range of from about 10 m −1 to about 40 m −1 , measured according to the well-known hook drop testing method. Where the degrees of entanglement are in that range, the precursor fiber bundle e.g. the original tow can be easily divided into a plurality, each of which is used for producing a useful carbon fiber bundle.
[0016] The process for producing a precursor fiber bundle having the above properties comprises the steps of dividing a fiber bundle consisting of a plurality of spun filaments into a plurality of sub-tows in such a way that each sub-tow comprises a predetermined number of filaments; drawing the filaments while in this state of division; collecting the plurality of drawn sub-tows into one tow potentially capable of being divided into a plurality of sub-tows when used for producing a carbon fiber bundle; and packing the product into a container. In this process, a plurality of groups each of which consist of a plurality of sub-tows may also be arranged to run in parallel each other.
[0017] The process for producing a carbon fiber bundle according to the present invention may also comprise the steps of dividing the precursor fiber bundle into a plurality of sub-tows; and subjecting the sub-tows to a stabilizing process and to a carbonizing process.
[0018] According to the present invention, the filaments taken up from a spinnerette are divided into a plurality of sub-tows, and the respective sub-tows are then collected into a single tow that is capable of being potentially divided into a plurality of sub-tows when used later for producing a carbon fiber bundle, and before they are packed into a container.
[0019] The precursor fiber bundle formed as a single tow is packed into a container, since the tow production speed is greatly different than the treatment speed of the subsequent carbonizing process. In the carbon fiber production process, the precursor fiber bundle formed as a single tow is taken out of the container and fed to a stabilizing process. In this case, it is divided into a plurality of sub-tows each of which has a predetermined thickness, before it is fed to the stabilizing process. Therefore, the problem of excessively stored heat, as described before, can be prevented from occurring, and carbon fibers that have the desired high strength and high modulus can be produced efficiently. In the final stage of the process for producing the precursor fiber bundle, the filaments are formed as one fiber bundle having a large total fineness, but the carbon fiber bundle after it has been produced is divided into a plurality of sub-tows each of which has a fineness suitable for stabilizing and carbonizing. Accordingly, the production of the precursor fiber bundle, and the production of the carbon fiber bundle can be carried out under remarkably efficient conditions.
[0020] The precursor fiber bundle of the present invention is preferably made of an acrylic polymer containing acrylonitrile, one or more unsaturated monomers selected from the following group A, and one or more unsaturated monomers selected from the following group B. They are present in amounts shown in the following equations (1), (2) and (3).
[0021] Group A comprises one or more unsaturated monomers selected from the group consisting of vinyl acetate, methyl acrylate, methyl methacrylate and styrene.
[0022] Group B comprises one or more unsaturated monomers selected from a group consisting of itaconic acid and acrylic acid.
[0023] The amounts are:
AN (wt %)≧86 (1)
3≦A (wt %)≦10 (2)
0.25 A− 0.5≦ B (wt %)≦0.43 A− 0.29 (3)
[0024] The symbols in the above formulae stand for the following:
[0025] AN represent the acrylonitrile content (wt %) in the acrylic polymer.
[0026] A represent the content (wt %) of the unsaturated monomer selected from said group A in the acrylic polymer (total weight of unsaturated monomers when a plurality of unsaturated monomers are present)
[0027] B represent the content (wt %) of the unsaturated monomer selected from said group B in the acrylic polymer (total weight of unsaturated monomers when a plurality of unsaturated monomers are present)
[0028] As shown by the formula (2), the weight percent (content) of the unsaturated monomer selected from said group A is in the range of from about 3 wt % to about 10 wt %. If the amount is less than about 3 wt %, the filaments are slightly less likely to stretch when drawn, and the tension in the stabilizing process is too high. If said amount is more than about 10 wt %, more filaments adhere to each other when stabilized, and carbonization at a lower temperature at a lower speed is required to prevent it. This raise production costs
[0029] Furthermore, as shown in the formula (3), the weight percent B of the unsaturated monomer B is in the range of from about (0.25×A−0.5) wt % to about (0.43×A−0.29 ) wt %. If the amount is less than the lower limit, acceleration of stabilization does not occur. If the amount is more than the upper limit, acceleration of stabilization becomes less efficient; this raises production costs.
[0030] The acrylic polymer may be produced by any known polymerization method such as suspension polymerization, solution polymerization or emulsion polymerization, etc. The polymerization degree is preferably about 1.0 or more expressed as intrinsic viscosity ([η]). The upper limit of intrinsic viscosity ([η]) is desirably about 3.0 or less since otherwise the production of the spinning dope itself is difficult, and since otherwise the spinning stability of the polymer is also remarkably lowered. The expression “intrinsic viscosity” refers to the value measured at 25° C. with dimethylformamide as the solvent.
[0031] The solution of the acrylic polymer, i.e., the spinning dope, is spun into an acrylic polymer fiber bundle using a coagulating bath of an organic solvent or water.
[0032] Spinning may be wet spinning in which a spinning dope is ejected from a spinnerette emersed in a coagulating bath, or may be semi-wet spinning in which a spinning dope is ejected from a spinnerette installed above the liquid surface of a coagulating bath with a distance between them, into air or inactive gas and introduced into the coagulating bath, or may be melt spinning.
[0033] In spinning using a solvent and plasticizer, the spun filaments may be drawn into a bath immediately, or after having been washed with water to remove the solvent and plasticizer.
[0034] The acrylic polymer fiber bundle obtained by any of these methods is drawn with a draw ratio in the range of from about 2 times to about 8 times in a drawing bath having a temperature of from about 50° C. to about 98° C. If the drawing ratio is too low, good densifying cannot be obtained, leaving voids, and the physical properties are likely to be poor. If the draw ratio is more than about 8 times, the tension during carbonization increases, requiring a larger apparatus. Drawing in a steam tube may be used with drawing in a bath, but in the case of drawing in a steam tube, it is preferable to keep the drawing ratio low to suppress orientation of fibers. However, drawing in a bath only is preferable.
[0035] Turning now to the number of filaments of the acrylic polymer fiber bundle, it is preferable to use a multifilament comprising a number of filaments in the range of from about 5×10 4 filaments to about 10×10 5 filaments to enhance production efficiency and cost reduction.
[0036] Subsequently, the filaments are dried under gentle air flow having a temperature in the range of from about 110° C. to about 180° C. or a heating roller under tension or relaxation, and are densified simultaneously. Prior to the drying and densifying, it is desirable to apply a proper oiling treatment to prevent adhesion between filaments and to facilitate handling of the dried and densified fiber bundle.
[0037] The dried and densified fiber bundle is shrunken at a ratio of from about 5% to about 18%. The shrinking treatment is intended to shrink the filaments under proper tension using a heating roller or any other heating means such as hot air, and this is effective to decrease the tension acting on the fiber bundle in the subsequent stabilizing process. For decreasing tension, a shrink treatment having a ratio of from about 5% to about 18% is important. The heating temperature is in the range of from about 80° C. to about 120° C., and it is preferable to maintain substantially no tension, but some tension may be applied for the convenience of process if it allows enough shrinkage to be achieved. The percentage of shrinkage may be controlled by combining the heat treatment temperature, the residence time and the tension. The fineness (d) of each of the filaments finally obtained is preferably in the range of from about 1 denier to about 2.0 deniers, more preferably of from about 1.0 denier to about 1.5 deniers, for higher productivity.
[0038] The precursor fiber bundle obtained as described above may be processed into a carbon fiber bundle by any conventional method. The stabilizing conditions in this case may be as in conventional methods. The fiber bundle is treated in an oxidizing atmosphere having a temperature in the range of from about 200° C. to about 300° C. under tension or while being drawn.
[0039] The shrinkage stress during stabilization of the acrylic polymer fiber bundle is related to the potential physical properties of the resulting carbon fiber bundle. When the raw fibers are higher in strength, that is, more highly oriented with greater shrinkage stress, the potential physical properties of the carbon fibers obtained are greater. However, in order to obtain such physical properties, it is desirable to control the shrinkage of fibers or rather to apply high tension to the fibers by drawing.
[0040] To obtain the physical properties of reinforcing carbon fibers for general industrial applications, high tension treatment is not required so much, and the problem in commodity design is to produce carbon fibers with good cost performance which can compete with conventional materials such as glass fibers, iron and aluminum in price.
[0041] Conventionally, carbon fibers having great tensile strength are generally produced by stabilizing precursor fibers with a high capability of shrinkage stress at a high tension, to produce as an intermediate product oxidized fibers (stabilized fibers) having a high degree of crystallite orientation and a high tensile strength. In such a high tension process, the occurrences of fuzz and breakage of fibers are likely to reduce quality and processability. The production conditions and equipment conditions are accordingly varied in an effort to prevent this. However, such approaches tend to raise the production cost of carbon fibers significantly.
[0042] On the contrary, according to the present invention, styrene, methyl acrylate or methyl methacrylate as a polymerizable unsaturated monomer is added to the acrylic polymer fibers, thereby achieving reduced shrinkage stress, thereby allowing the tension in the stabilizing process also to be reduced. The tension in the stabilizing process can be kept low, thus minimizing the occurrences of fiber breakage and fuzz in the stabilizing process.
[0043] Furthermore, a carbon fiber bundle of about 25,000 deniers or more in fineness, substantially having no twist, and of from about 10 m −1 to about 100 m −1 in the degree of entanglement measured according to the hook drop test can be obtained. Its physical properties are in the range of from about 2.0 GPa to about 5.0 GPa, preferably from about 3.0 GPa to about 4.5 GPa in tensile strength and in the range of from about 200 GPa to about 300 GPa in elastic modulus. These carbon fibers may be used for general purpose. Herein, the expression “substantially no twist” means the twist count per meter is not more than 1 turn of twist.
[0044] It is preferable that the tension T in the stabilizing process approximately satisfies the following formula (4).
30≦T (mg/d)≦120 (4)
[0045] More preferably, the tension T is in the range of from about 60 mg/d to about 100 mg/d. If the tension T is less than about 30 mg/d, the tension is so low as to shrink the fibers, and to lower the degree of crystallite orientation, and the fibers obtained are low in tensile strength. If the tension T is more than about 120 mg/d, good physical properties can be obtained, but since the tension is so high, the return rollers must be especially strong or of large diameter. The equipment must be so heavy as to be industrially undesirable. If return rollers that are large in diameter are installed for the stabilizing furnace, it is difficult to achieve a high frequency return, making mass processing difficult. Also in view of this, it is not desirable to keep the tension excessive.
[0046] In the present invention, since the tension T in the stabilizing process is controlled to low range of from about 30 mg/d to about 120 mg/d, the load per unit filaments acting on the rollers is light, and unprecedented consistent carbon fiber production allows very favorable mass processing. Therefore, no excessive size equipment is necessary; general purpose carbon fibers can be produced by use of inexpensive equipment, and very advantageously in view of production cost reduction. As a result, carbon fibers may now be used for applications where they could not have been used because of high cost.
[0047] The effect of cost reduction by achieving low tension is further described below.
[0048] Firstly, cost reduction can be obtained through process stability. A lower tension is effective for decreasing the creation of fuzz and fiber breakage in the strand formed as an aggregate of many short fibers during processing. Hence, the process is very effective to decrease production mishaps such as the seizure of filaments and the strand on the rollers. The amount of generated fuzz is directly related to processability. The low tension also has a good minimizing effect upon the amount of fuzz. The amount of fuzz created is a good indicator for evaluating the overall processability of the method.
[0049] Secondly, an important cost reduction can be obtained through the enhanced volume availability in the stabilizing furnace. In the carbon fiber production process, since a strand to be processed is continuously processed, a series of rollers is usually used. Since these rollers are deflected in response to the tension of the strand, a deflection which poses no problem in equipment or process stability is achieved by this invention. In the case of a cylindrical roller of uniform diameter, the maximum deflection is proportional to the product of the tension and the 4th power of (roller length L/roller diameter D). Therefore, in general, if the tension is doubled, the deflection is doubled, and to lower the doubled deflection to the original deflection, the diameter must be increased to 1.2 times. The diameter of a roller especially directly affects the volume availability of the stabilizing furnace; and if the diameter of a roller is decreased, the volume availability of the stabilizing furnace is higher, and this significantly enhances carbon fiber productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] [0050]FIG. 1 is a schematic side view schematically showing an apparatus for producing a precursor fiber bundle in accordance with the present invention.
[0051] [0051]FIG. 2 is a plan view showing a typical portion of running and divided sub-tows in a coagulating bath in the spinning step performed by a portion of the apparatus shown in FIG. 1.
[0052] [0052]FIG. 3 is a schematic side view showing an apparatus for practicing a process for producing carbon fibers according to the present invention.
[0053] [0053]FIG. 4 is a plan view showing a portion of typical running sub-tows collected as a single tow in the apparatus shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] The following description is directed to specific forms of the invention selected for illustration in the drawings. It is not intended to define or to limit the scope of the invention, which is defined in the appended claims.
[0055] The precursor fiber bundle of the present invention is, as described, specially constituted to maintain the form of a single tow when packed in a container, and potentially can be divided into two or more sub-tows when taken out of the container, to be subjected to stabilizing.
[0056] The precursor fiber bundle is produced, for example, by a process as shown in FIG. 1.
[0057] In a spinning step 1 , a plurality of filaments are spun from a spinnerette. The spinning method is not especially limited, and may be, for example, any known wet spinning in which many filaments are spun from a spinnerette and coagulated in a coagulating bath, for example. The plurality of spun filaments are divided into a plurality of sub-tows each of which comprises a predetermined reduced number of filaments. This division is carried out in the coagulating bath, or desirably at the outlet of the coagulating bath in the case of wet spinning. The division may be practiced by using a dividing bar, for example. FIG. 1 does not illustrate the divided tows since it is a side view. When the process is viewed from above, the divided arrangement can be identified.
[0058] [0058]FIG. 2 is a plan view showing typically a portion of the separate running of the divided sub-tows in the coagulating bath of FIG. 1. In FIG. 2, it is shown that the spun multifilament is divided into the plurality of sub-tows 2 , 2 by the dividing bar 18 having an elliptical cross section. The divided tows run in the direction shown by arrows 19 , 19 in FIG. 2.
[0059] The group 2 of sub-tows comprising a plurality of sub-tows divided from the spun multifilament is fed to a filament drawing step 3 (FIG. 1) and a finish oiling step 4 in a divided configuration.
[0060] In this example, the sub-tow group 8 (FIG. 1) delivered from the oiling step 4 is fed to a crimping step 5 where the sub-tow group 8 is crimped. Each of the sub-tows in the sub-tow group 8 is collected into the form of one tow 9 (FIG. 1). This convergence of sub-tows is brought about with weak entanglment of filaments located in the side edge portions of each of the adjacent sub-tows as a result of the crimping. This entanglement, extending the length direction of the filaments at their side edge portions, is weak. Therefore, the fiber bundle formed as a single tow 9 can be re-divided into sub-tows forming the sub-tow group 8 (FIG. 1) at the side edge portions of the sub-tows. That is, the precursor fiber bundle 10 (FIG. 1) in the form of a single tow delivered from a drying step 6 (FIG. 1) subsequent to the crimping step 5 has potential dividability into a plurality of sub-tows.
[0061] The precursor fiber bundle 10 thus formed is packed in a can 12 (FIG. 3) in a packing step 7 (FIG. 1).
[0062] In producing the precursor fiber bundle shown in FIG. 1, it is also possible to divide a spun multifilament into a plurality of groups 8 each of which comprises a plurality of sub-tows for preparing a plurality of precursor fiber bundles 9 in parallel, each of which bundles 9 is dividable into a plurality of sub-tows in the desired number. Parenthetically, a bale may be used instead of a can as the container for packing the precursor fiber bundle 10 .
[0063] The precursor fiber bundle 11 so produced is sent to a carbon fiber production process, shown as packed in the can 12 . It is once packed in a container because the process for producing the precursor fiber bundle has a greatly different fiber processing speed than the process for producing the carbon fibers.
[0064] A carbon fiber bundle can be produced, for example, according to the process shown in FIG. 3.
[0065] The precursor fiber bundle 11 is aupplied as packed in the can 12 . Where processing simultaneously a plurality of the precursor fiber bundles 11 , as many cans as necessary are prepared (shown as three in number, in FIG. 3).
[0066] Each precursor fiber bundle 11 taken out of the can 12 is divided into sub-tows in a dividing step 13 upstream of a stabilizing furnace 14 . The division can be practiced by using, for example, a grooved roll or dividing bar. Since the sub-tows are collected or converged with weak side edge portion entanglements, such division can be accomplished very easily. In the division step, very little fuzz formation or fiber breakage occur.
[0067] Each divided sub-tow is stabilized in the stabilizing step 14 . Stabilization is effected by heat treatment in an oxidizing atmosphere having a temperature in the range of from about 200° C. to about 350° C. in the stabilizing furnace 14 . Since each of sub-tows has a predetermined relatively small size, excessive heat storage does not occur, and the fiber breakage and the adhesion between filaments during the stabilizing treatment can be, and are prevented.
[0068] The stabilized sub-tows are then fed to a carbonizing step 15 and further, as required, to a surface treatment step 16 such as a sizing step, and formed as a carbon fiber bundle, wound in a winding step 17 . Since the stabilizing treatment is effected against sub-tows each of which has a controlled and proper reduced thickness, the carbon fibers obtained are excellent in strength and elastic modulus.
[0069] It is preferable that the precursor fiber bundle has a total fineness of from about 300,000 denier to about 1,500,000 denier, more preferably from about 400,000 denier to about 1,200,000 denier, and it is preferable that each of the sub-tows finally obtained from the precursor fiber bundle having potential dividability has a fineness of from about 50,000 denier to about 250,000 denier, more preferably from about 80,000 denier to about 150,000 denier.
[0070] If the precursor fiber bundle has a fineness of less than about 300,000 denier, the degree of entanglement between filaments is likely to be less than about 10 m −1 , and the degree of entanglement of the filaments is low. Such low entanglement causes deformation of tow; where such tow is stabilized irregular tension occurs due to dislocation between filaments, to cause fiber breakage.
[0071] If the total fineness is more than about 1,500,000 denier, the adhesion between filaments becomes strong, to increase drawing nonuniformity and fiber breakage, thus lowering the productivity in filament drawing and carbonization. If fineness of each of the divided sub-tows is less than about 50,000 denier, the productivity in the carbonizing step is too low. If it is more than about 250,000 denier, irregular carbonization occurs and lowers quality.
[0072] If the precursor fiber bundle is crimped, adhesion between filaments is likely to be removed and the strength of carbon fibers is likely to be manifested. A desirable number of crimps of the zig-zag type is in the range of from about 8 peaks per 25 mm to about 13 peaks per 25 mm, preferably from about 10 peaks per 25 mm to about 12 peaks per 25 mm. If it is less than about 8 peaks per 25 mm, the adhesion between filaments is likely to persist, and the strength of carbon fibers is unlikely to be manifested. If more than about 13 peaks per 25 mm, the filaments tend to buckle, reducing strength.
[0073] The number of crimp is effectively measured as a mean value of 20 measuring samples, each number being measured as follows. A single filament as a sample is taken out of a precursor fiber bundle and is weight 2 mg/d. The number of peaks of crimp in the weighted sample is counted over a predetermined length taking along the straight lengthwise direction of the sample, and the result is converted to a length of 25 mm.
[0074] The precursor fiber bundle in the present invention can also be a non-crimped tow (a straight tow having substantially no crimp). In the case of the non-crimped tow, since the degree of entanglement of filaments is very small, it is desirable to cause the filaments to contain moisture for enhancing the collectability. The moisture content in this case is desirably in the range of from about 10% to about 50%. If less than about 10%, collectability is too low, and if more than about 50%, the packing rate may become too low.
[0075] The moisture content is obtained as a result of an equation of (10−B)×100/B, where B is the weight obtained by the following measurement. A tow of 10 g as a sample is taken out of a precursor fiber bundle, dried with a hot-air dryer for 2 hours at 105° C., and placed a in a desiccator containing a drying agent for 10 minutes, and the weight of the sample is measured. The observed value of the weight is used as B in the above equation
[0076] In the process for producing a precursor fiber bundle, after spinning a polymer solution through a spinnerette for forming a multifilament and coagulating the spun multifilament, the multifilament can be divided as desired. It is preferable that the dividing bar used in this case does not allow any substantial frictional force to act on the tow, and not to damage the tow as much as possible, but the dividing bar is not especially limited as to material or form. However, the width of the dividing portion of the bar is important. It is preferable that the dividing portion has such a width as to ensure that the side edge portions of adjacent divided sub-tows are overlapped each other by about 1 mm when they are finally collected as a tow, if the tow is non-crimped tow or a crimped tow. It is preferable that the guide width ensures that the side edge portions of the adjacent sub-tows are engaged with each other by about 1 mm before they are crimped. If such a divided state cannot be ensured by the division in the coagulating step only, a further dividing operation may be added in another step, to control the side edge portions of the adjacent sub-tows to engage with each other by about 1 mm, before they are crimped. The cross section of the dividing bar is preferably formed as ellipsoidal or rhombic, etc. and as small as possible in contract area, to ensure that the filaments constituting the tow are not significantly rubbed or damaged by the dividing bar. Especially in the case of a bar having an ellipsoidal cross section, it is preferable to place the major axis and the running direction of tow at a substantially right angle. Such a relationship is shown in FIG. 2 (dividing bar 18 ). FIG. 4 is a plan view showing typically the state of overlapping, where the overlapping is labeled with the mark OL.
[0077] For example, when a tow is divided into sub-tows each of which has a fineness of about 50,000 deniers or more, the running space, which is shown with the mark D in FIG. 2, between adjacent sub-tows divided in the drawing step is preferably in the range of from about 1.5 cm to about 2 cm. If less than about 1.5 cm, the adjacent divided sub-tows tend to engage too intensively with each other at their side edge portions. This causes an increase of fiber breakage and fuzz generation when the tow is re-divided in the stabilizing step. Further, it causes trouble in carbonizing and reduces the quality of the carbon fiber bundle. If this running space is more than about 2 cm, the sub-tows are less firmly engaged with each other at their side edge portions, and the sub-tows are taken up irregularly when forming the non-crimped tow, or in a step of forming the crimped tow, and it causes dislocation of filaments in the longitudinal direction. Furthermore, the tow itself is deformed.
[0078] The following Examples are illustrative of the invention. They were performed by us, or by others working under our supervision, and all reported results are true and correct to the best of our knowledge and belief.
EXAMPLES 1 TO 10, AND COMPARATIVE EXAMPLE 1
[0079] A dimethyl sulfoxide (DMSO) solution of an acrylic polymer consisting of acrylonitrile (AN)/methyl acrylate (MEA)/sodium methacrylsulfonate (SMAS)/itaconic acid (IA) 93.5/5.5/0.5/0.5 (by weight) was introduced into 60% DMSO aqueous solution of 30° C., and a fiber bundle of 400,000 denier was wet-spun, and divided into four sub-tows each of which has a fineness of 100,000 denier at the outlet of the coagulating bath. In this process, an elliptical dividing bar 18 (see FIG. 2) having a length of the major axis (LMA) of 1.5 cm was used in Example 1, a length of the major axis of 1 cm was used in Example 2, and a length of the major axis of 2.5 cm was used in Example 3. They were drawn, washed with water, oiled, and crimped with a conventional stuffing box type crimper. In Comparative Example 1, the fiber bundle was not divided during the coagulating step but divided only just before it was crimped.
[0080] Non-crimped sub-tows obtained after washing with water in Example 1 were treated with finish-oil to adjust their moisture contents of 2.5%, 40% and 60% respectively in Examples 4, 5 and 6.
[0081] A fiber bundle of 270,000 deniers was wet-spun and divided into three sub-tows each of which had a fineness of 900,000 denier at the outlet of the coagulating bath. In this process, as Example 7 an elliptical dividing bar 18 (see FIG. 2) having a length of the major axis of 1.5 cm was used. A fiber bundle of 400,000 denier was wet-spun and divided into 10 sub-tows each of which has a fineness of 40,000 denier at the outlet of the coagulating bath. In this process, as Example 8 an elliptical dividing bar 18 (see FIG. 2) having a length of the major axis of 1.5 cm was used. A fiber bundle of 1,600,000 denier was wet-spun and divided into 16 sub-tows each of which has a fineness of 100,000 denier at the outlet of the coagulating bath. In this process, as Example 9 an elliptical dividing bar 18 (see FIG. 2) having a length of the major axis of 1.5 cm was used. A fiber bundle of 1,600,000 denier was wet-spun and divided into 40 sub-tows each of which has a fineness of 40,000 denier at the outlet of the coagulating bath. In this process, as Example 10 an elliptical dividing bar 18 (see FIG. 2) having a length of the major axis of 1.5 cm was used. In Examples 7-10, the sub-tows were respectively drawn, washed with water, oiled, crimped and dried. Sample having a length of 5,000 m was taken in each of Examples 1-10 and Comparative Example 1 for evaluating dividability, the degree of entanglement and adhesion. The results are shown in Table 1.
[0082] The methods for evaluating the respective properties in the examples were as described below.
[0083] (i) Dividability:
[0084] For evaluating the dividability, a crimped tow 5000 m long was divided manually from end to end. A sample which was poor in dividability and had to be divided forcibly by scissors, etc. was designated as “Δ”; a sample which could not be divided due to fiber breakage or defective division was designated as “x”; and a sample which could be simply manually divided over the entire length was designated as “∘”.
[0085] (ii) Degree of entanglement of a precursor fiber bundle, measured according to the hook drop testing method:
[0086] A precursor fiber bundle (tow) was hang on a horizontal setting bar with a fineness of 20,000 denier/cm and fixed at the upper end portion of the bundle on the bar with an adhesive tape. On the lower end portion, a weighing bar of 20 g/10,000 denier was fixed with an adhesive tape. A wire having a diameter of 1 mm and its tip portion having a length of 2 cm bent at right angle, and carrying fixed a weight of 100 g at its lower end, wass prepared. The wire was hooked on the hanging bundle with the bent tip portion and allow to fall in downwardly freely. The falling distance X (in meters) of the wire until the hook engaged the tangle was measured. Such falling distance X (in meters) was measured at 20 different positions with a substantially equal interval along the width of the hanged bundle. The mean value (Xm) of the 20 measuring data (X) was calculated. The degree (CFP) (in 1/m=m −1 ) of entanglement of a precursor fiber bundle was obtained by the following formula.
Degree of entanglement (CFP)=1/Xm
[0087] (iii) Adhesion:
[0088] A volume of filaments having a length of 5 mm which was obtained by cutting a precursor fiber bundle was prepared as a measuring sample so that the volume was equal to about 10,000 filaments in a precursor bundle (where the fineness of single filament is 1.5 denier, the volume become 0.0084 g). A rotor and 100 ml of 0.1% Noigen SS were put into a beaker, and the sample was added. They were stirred by a magnetic stirrer for 1 minute, and the mixture was suction-filtered using black filter paper, to visually judge the dispersibility of fibers in reference to six grades. The 1st grade is the best in adhesion and the 6th grade, the worst.
[0089] As described above, according to the present invention, a precursor fiber bundle can maintain the form of one tow when packed in a container, and can be easily divided in the crosswise direction into sub-tows each of which has a desired fineness when used for producing carbon fibers (when supplied to the stabilizing step). So, a thick (large in fineness) precursor fiber bundle can be produced at a very high productivity, and in the carbon fiber production process, it can be divided into sub-tows each of which has a predetermined thickness to allow stable stabilizing treatment. Therefore, both the productivity improvement of the precursor fiber bundle and the stable production of carbon fibers having an excellent properties can be simultaneously achieved which contributes significantly to reduction of cost for producing carbon fibers.
EXAMPLES 11 TO 13 AND COMPARATIVE EXAMPLES 2 TO 6
Example 11
[0090] 92.3 wt % of acrylonitrile, 6.3 wt % of methyl acrylate and 1.4 wt % of itaconic acid were polymerized in a nitrogen gas atmosphere at 60° C. for 11 hours and furthermore at 73° C. for 9 hours by solution polymerization with dimethyl sulfoxide as the solvent. The polymer solution obtained as a spinning dope was 22.5% in concentration and 240 cps in viscosity. It was extruded from a spinnerette that had 70,000 holes of 0.055 mm in diameter into 55% dimethyl sulfoxide aqueous solution of 40° C., to be coagulated. The fiber bundle obtained was drawn to 5 times in hot water while being washed, subsequently oiled, dried and densified by a drying drum, and treated to be shrunken by 15% in 113° C. air, to obtain a precursor fiber bundle, made of an acrylic polymer and of 1.5 d in filament fineness. Then, it was stabilized in air at 210° C. to 250° C., and heated up to 1,400° C. in nitrogen atmosphere, to obtain carbon fibers. In succession, they were electrolyzed at 10 coulombs/g with a sulfuric acid aqueous solution of 0.1 mole/liter in concentration as the electrolyte, washed with water and dried in 150° C. air. The carbon fibers obtained here were impregnated with an epoxy resin according to the method specified in JIS R 7601, to measure the tensile strength and elastic modulus of the strand by a tensile tester. The conditions in this case and the physical properties of the resulting carbon fibers are shown in Tables 2a and 2b. It can be seen that even with low tension during stabilization, the physical properties of the resulting carbon fibers are very good.
Example 12
[0091] Carbon fibers were obtained as described in Example 11, except that 96.1 wt % of acrylonitrile, 3.2 wt % of methyl acrylate and 0.7 wt % of itaconic acid were polymerized, and that the shrinkage percentage was 7%. The conditions in this case and the physical properties of the obtained carbon fibers are shown in Tables 2a and 2b.
Example 13
[0092] Carbon fibers were obtained as described in Example 11, except that 86 wt % of acrylonitrile, 10 wt % of methyl acrylate and 4 wt % of itaconic acid were polymerized, and that the shrinkage percentage was 18%. The conditions in this case and the physical properties of the obtained carbon fibers are shown in Tables 2a and 2b.
Comparative Examples 2 and 3
[0093] Carbon fibers were obtained as described in Example 11, except that 99.3 wt % of acrylonitrile and 0.7 wt % of itaconic acid were polymerized, and that the shrinkage percentage was 5%. The conditions in this case and the physical properties of the obtained carbon fibers are shown in Tables 2a and 2b. Since the monomer as the second component (group A) was not contained, the physical properties of carbon fibers were poor when the tension during stabilization was low.
Comparative Example 4
[0094] Carbon fibers were obtained as described in Example 11, except that the fiber bundle was drawn in a bath and in steam by 12 times in total. The conditions in this case and the physical properties of the obtained carbon fibers are shown in Tables 2a and 2b.
Comparative Example 5
[0095] Carbon fibers were obtained and evaluated as described in Example 12, except that the drawn fiber bundle was not treated to be shrunken. The results are shown in Tables 2a and 2b.
Comparative Example 6
[0096] Carbon fibers were obtained as described in Example 12, except that the drawn fiber bundle was treated to be shrunken by 2%. The results are shown in Tables 2a and 2b.
[0097] The methods for evaluating the properties in the examples were as described below.
[0098] (iv) Fuzz Generation:
[0099] From a precursor fiber bundle, ten 1 m long samples were taken. From each of the samples, a fiber bundle consisting of from 1,000 filaments to 2,000 filaments was divided and taken, and the number of particles of fuzz in a length range of 0.5 m at the center was counted on an illuminated cloth inspection table. The mean value of 10 samples was calculated in numbers/m 10K (number of fuzz particles existing in 10,000 filaments of 1 m in length), and the value was adopted as the fuzz generation number. The fuzz generation number of the precursor fiber bundles made of an acrylic polymer used in Examples 11 to 13 were 8 to 9 numbers/m 10K.
[0100] (v) Degree of entanglement of carbon fiber bundle measured according to the hook drop testing method as described herein:
[0101] A carbon fiber bundle was hanged on a horizontal setting bar and fixed at the upper end portion of the bundle on the bar with an adhesive tape. On the lower end portion, a weight bar of 200 g was fixed with an adhesive tape. A crochet needle with a weight of 10 g was pierced through the carbon fiber bundle, and the crochet needle free drop distance X (in cm) until stopped by fibers was measured 50 times. Of the measured values, the 10 largest values and the 10 smallest values were excluded, and the mean value Xm (in cm) of the remaining measured values was used, to obtain the degree of entanglement (CFC) (in 1/M =m −1 ) of the carbon fiber bundle according to the hook drop testing method, using the following formula:
Degree of entanglement (CFC)=100/Xm
[0102] [0102] TABLE 1 Produc- LMA of Mois- Degree tivity Divid- ture of Adhes- of ing bar Content Divid- Entangle- ion Carbon- (cm) (%) ability ment (grade) ization Example 1 1.5 — ∘ 22.2 1.5 ∘ Example 2 1.0 — Δ 17.3 1.5 ∘ Example 3 2.5 — ∘ 28.3 1.5 ∘ Example 4 1.5 2.5 ∘ 8.3 3.0 Δ Example 5 1.5 40 ∘ 11.9 3.0 ∘ Example 6 1.5 60 ∘ 13.4 3.0 Δ Example 7 1.5 — ∘ 8.2 1.5 Δ Example 8 1.5 — ∘ 23.4 1.5 Δ Example 9 1.5 — Δ 42.5 6.0 Δ Example 10 1.5 — Δ 43.5 6.0 Δ Comparative dividing just x — — — Example 1 before crimping: could not be divided due to too often fiber breakage
[0103] [0103] TABLE 2a Stabilization Temperature Time Drawing Tension (° C.) (min) Ratio (mg/d) Example 11 225/230/245/252 110 1.2 95 Example 12 225/230/245/252 110 1.2 100 Example 13 215/225/235/245 180 1.3 80 C-Example 2 225/230/245/252 110 1.0 140 C-Example 3 225/230/245/252 110 0.95 110 C-Example 4 225/230/245/252 110 1.0 135 C-Example 5 225/230/245/252 110 1.0 140 C-Example 6 225/230/245/252 110 1.0 130
[0104] [0104] TABLE 2b Physical Properties of Carbon Fibers Stabilization Elastic Degree of Number of Fuzz Strength Modulus Entanglement (particles/m 10 K) (GPa) (GPa) ( −1 m) Example 11 8 3.5 230 30 Example 12 8 3.5 250 30 Example 13 9 3.4 230 30 C-Example 2 30 3.6 250 — C-Example 3 9 2.9 220 — C-Example 4 22 3.5 250 — C-Example 5 25 3.5 250 — C-Example 6 14 3.5 250 — | A separable tow of elongated polymeric filaments comprises a plurality of distinct sub-tows lightly and individually and separably joined, as by light crimping together along their edges or, if uncrimped, joined by presence of moisture, and capable of being packed into a container and later removed and separated. The filaments are preferably acrylic and have a total fineness of about 300,00-1,500,000 denier and the sub-tows each of which has a total fineness of about 50,000-250,000 denier, with a filament fineness of about 1-2 denier, and each sub-tow has a degree of entanglement of about 10-40 m −1 as measured by the hook drop test.
The separable tow is made of a plurality of sub-tows, after separately drawing the sub-tows and subsequently removably joining the sub-tows into a single tow. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
FIELD OF THE INVENTION
This invention relates to steam cleaning devices, and more particularly, to a jewelry cleaning device utilizing a jet of steam which is suitable for personal use.
BACKGROUND OF THE INVENTION
Rings, bracelets, necklaces, watches, gems, earrings, and the like present a collection of various types of jewelry which many people today own and wear due to their aesthetically pleasing appearance. Nevertheless through daily wear, this jewelry can become dirty and tarnished thus diminishing their sightly appearance. Therefore, these items must be periodically cleaned in order to maintain their original beauty. Liquid jewelry cleaning formulations which have been developed for this purpose have enjoyed limited success, due mainly to the fact that several common forms of dirt and grime are unaffected thereby. Steam cleaning devices on the other hand have been known for a long time as a valid means of thoroughly cleaning most forms and dirt and grime from jewelry pieces; however, the use of these steam cleaning devices for jewelry items have largely been relegated to jewelry stores and other similar commercial establishments due to their rather large size and complicated design.
A number of steam cleaning devices have been developed which disclose a means of cleaning jewelry via a relatively high velocity stream of water vapor or steam and examples of such devices includes U.S. Pat. No. 2,753,212 to Aultman, and U.S. Pat. No. 4,414,037 to Friedheim. In addition, U.S. Pat. No. 4,941,490 to Gross discloses a jewelry cleaning means utilizing a high velocity stream of air mixed with a relatively low temperature cleaning solution. Although all of these devices provide an effective method of cleaning jewelry, they suffer in that they are of complex design thus rendering them cost-prohibitive for personal use. Moreover, these complex designs which have been relegated to commercial use have further compounded the problem of complexity in that more stringent safety mechanisms are necessary due to their operation in a commercial environment, thereby further raising their costs. This is due in part to the fact that their use in a commercial environment has necessitated relatively large sized mechanisms which are able to handle high levels of usage.
Auxiliary mechanisms for steam cleaning devices that have been developed to provide a containment structure for jewelry items being cleaned include U.S. Pat. No. 4,949,738 to Hubbard and U.S. Pat. No. 6,129,097 to Papandrea. Each of these devices discloses a means of insuring that small gems which are inadvertently dislodged from the jewelry piece remain within a containment structure during the cleaning process. Similarly to the large steam cleaning devices to which they are attached, these devices are large bulky items and thus generally unsuitable for personal use.
Thus, there has been a long-felt need for a jewelry cleaning device which is sufficiently small and simple in design to enable its use in a residential environment. Moreover, the device's simple, non-complex construction should thus be inexpensive to produce as well as easy to maintain thereby enabling the personal use thereof.
SUMMARY OF THE INVENTION AND OBJECTIVES
The present invention provides a solution to these as well as other needs via a jewelry cleaning device which is small and inexpensive to produce thereby allowing its usage in a residential environment. The device generally comprises a steam generator in fluid communication with a spout which emits a high velocity jet of steam under manually operable control means whereby jewelry items may be effectively cleaned thereby. The jewelry cleaning device of the present invention is lightweight and relatively compact in size thus enabling its use on virtually any tabletop and is easily stored when not in use. The steam generator is commensurately small in size thus minimizing the severity of any safety hazard produced via any of the potential failure modes thereof. The steam generator is powered by conventional electrical power and is controlled by means of a thermostat to maintain the water/steam mixture at a predetermined temperature while in operation. Safety mechanisms include a pressure relief valve to automatically expel steam from the generator when the internal pressure thereof exceeds a predetermined level and a thermal fuse configured in a series connection with the heating element of the steam generator.
Optionally, a containment device is provided in order to trap gems or other small parts which are inadvertently dislodged from the jewelry piece during the cleaning operation. The containment device, which is made of screen mesh and fashioned into a cup-like shape, is slidably engaged onto the sidewall of the jewelry cleaning device and is disposed underneath the spout in such a manner that the entire jet of steam passes therethrough. The mesh of the screen is sufficiently fine to trap any sized gem on its upper surface yet allows the steam stream to easily pass therethrough.
One aspect of the present invention contemplates a jewelry device that is inexpensive to produce and maintain. The present invention utilizes a steam generation means having a design that has been approved for use in residential environments by unskilled operators though the supervisory safety regulatory agencies, yet heretofore has not been known to the art of jewelry cleaning. The present invention's design also differs from the prior known steam cleaning devices for jewelry in that the supervisory regulatory agencies do not require periodic maintenance or inspection thereof, thus further reducing costs. In addition, the relatively small size and lightweight design provides for inexpensive materials costs as well as inexpensive shipping and handling costs.
Another aspect of the present invention is a jewelry cleaning device that is easy to use. The jewelry cleaning device has relatively few moving parts and requires no adjustment mechanisms, thereby allowing use by an unskilled user. The temperature within the steam generator is automatically controlled in order to maintain a constant pressure thereby obviating the need for user adjustment, whereby a consistent spray pattern is always available to the user upon demand. In addition, the present invention exists as a compact space-efficient package, not having any bulky elongated flexible hoses or other cable control structures attached thereto. This compact design also provides for easy storage of the device when not in use.
It is therefore an object of the present invention to provide a jewelry cleaning device which is relatively inexpensive to produce as well as to maintain, thereby enabling the personal use thereof.
A further object of the present invention is to provide a jewelry cleaning device utilizing a pressurized steam generation means to deliver a relatively high velocity jet of steam requiring no external adjustment mechanisms in order to enable its use by an unskilled user.
A related object of the present invention is to provide a jewelry cleaning device which is relatively compact in size thereby allowing the easy storage thereof when not in use.
Another object of the present invention is to provide a jewelry cleaning device having a gem containment means for the trapping of small gems which become dislodged from the jewelry piece during the cleaning operation that is relatively small and lightweight and is releasably attachable thereto.
These and other objects of the present invention will become readily apparent to those familiar with the construction and use of steam cleaning devices and will become apparent in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a preferred embodiment of the present invention showing the entire device as a self-contained unit suitable for use on a conventional tabletop.
FIG. 2 is a front elevational view of the embodiment of FIG. 1 .
FIG. 3 is a side elevational view of the embodiment of FIG. 1 .
FIG. 4 is a rear elevational view of the embodiment of FIG. 1 showing a vertically oriented, elongated depression in the rear sidewall into which tongs are releasably disposed.
FIG. 5 is an elevational cross-sectional view of the embodiment of FIG. 2 taken at 5 — 5 .
FIG. 6 is a plan view of the slidably removable catch basket of the embodiment of FIG. 1 .
FIG. 7 is a side elevational view of the slidably removable catch basket of FIG. 6 .
FIG. 8 is a side elevational view of the valve actuator button of the embodiment of FIG. 1 .
FIG. 9 is a front elevational view of the valve actuator button of FIG. 8 .
FIG. 10 is a plan view of the rocker arm of the embodiment of FIG. 1 .
FIG. 11 is a side elevational view of the rocker arm of FIG. 10 .
FIG. 12 is a front elevational view of the rocker arm of FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 through 4 , a jewelry cleaning device embodying a preferred embodiment of the instant invention is designated generally by reference numeral 10 . The jewelry cleaning device is generally shown having a housing for enclosing a steam generator (to be described later), a pressure safety cap 85 , a valve actuator button 100 , and a steam tube 64 for directing a jet of steam downwards through a removable catch basket 30 . The steam tube 64 has a terminating end 65 which is constricted in order to emit the steam at a relatively high velocity. The valve actuator button 100 is selectively operable by a user to cause a momentary burst of steam to emanate from the terminating end 65 of the steam tube 64 . The space directly below the terminating end 65 of the steam tube 64 which includes the relatively high velocity jet of steam that is above the catch basket 30 defines a cleaning zone 17 whereby jewelry or other small items may be cleaned thereby. The catch basket is provided to trap small gems which may inadvertently become dislodged during the cleaning operation.
The housing shown generally comprises an upper wall 11 , and left 12 , right 13 , rear 14 , front 15 , and bottom 21 sidewalls made of any thermoplastic material, preferably polypropylene. The front sidewall 15 is generally concave in shape having an aperture 16 proximate the upper wall 11 thereof for receipt of the steam tube 64 therethrough. The front sidewall 15 is generally concave in shape in order to conform to the lateral space defined by the cleaning zone and to minimize the lateral distance which the steam tube must protrude beyond the front sidewall. The front sidewall 15 also has a catch basket retaining member 18 which extends laterally across the front wall 15 having a slot 19 formed therein to slidably receive the rim 32 of the catch basket 30 . The front edge of the upper wall 11 is integrally attached to the front sidewall 15 to define an adjoining edge 20 which is chamfered in order to create an aesthetically pleasing finish. In addition, the aesthetic appeal of the housing is further enhanced by the multi-tiered contour of the left 12 and right 13 sidewalls. The rear sidewall sidewall 14 is selectively removable in order to provide access to the contents of the housing. The rear sidewall 14 is removably attached via screws 23 which are inserted through cup-shaped depressions 22 in the rear sidewall 14 and anchored to pedestals 24 which are integrally attached to the left 12 and right 13 sidewalls as best shown in FIG. 5 . The jewelry cleaning device 10 of the present invention also includes an elongated depression 26 disposed in the rear sidewall 14 for placement of tongs 27 therein. The tongs 27 provide a means of holding the jewelry piece during the cleaning operation. The width of the depression 26 is chosen such that the tongs 27 are removably held therein with a snug fit. A finger access depression 28 is included which is adjoined to the elongated depression 26 in order to allow easy access to the tongs 27 by a user.
The catch basket 30 which is shown in greater detail in FIGS. 6 and 7 , has a screen member 31 formed into a hemi-ellipsoid shape whose upper edge is attached to a rim 32 . The rim 32 comprises an annular ring portion 33 which extends around the entire circumference of the screen 31 and a lip portion 34 which is integrally attached to the ring portion 33 for slidable insertion into the slot 18 . FIGS. 1 through 3 show the catch basket in the inserted position, however, the user may optionally remove the catch basket from the housing by pulling the catch basket 30 away from the housing, thereby enabling the cleaning of larger items or for the efficient storage thereof.
As shown in FIG. 5 , the steam generator includes a canister portion 41 made of any metal, preferably aluminum, which has a maximum water holding capacity of up to approximately 16 ounces of fluid, and most preferably about 8 ounces of fluid. The canister portion 41 has a cup-shaped neck member 42 which is integrally attached to a generally frusto-conical shaped body member 43 , and a bottom member 44 which is removably attached to body member 43 with a heat resistant gasket 46 sandwiched therebetween to form a pressure tight chamber for the heated steam/water mixture. Removable attachment of the bottom member 44 to the body member 43 is provided by bolts 47 which extend through apertures formed in the bottom member 44 as well as apertures formed in flanges 51 which are integrally attached to body member 43 . Conical shaped depressions 54 in the walls of the body member 43 allow access to the associated nuts of the bolts 47 . A pedestal 60 is provided for support of the canister 41 within the housing. The pedestal 60 is integrally attached to the bottom member 44 and extends downward therefrom to the bottom sidewall 21 and is secured thereto with bolt 61 .
The bottom member 44 has an annular slot 56 for housing a ring-shaped heater element 57 therein. The heater element 57 is preferably an 800 watt calrod device. The bottom member 44 also has a thermostat 58 mounted thereto which is electrically connected to the heater element 57 via a series connection which turns on power to the heater element when the canister temperature drops below a first predetermined threshold and turn off power when the temperature goes above a second predetermined threshold. To prevent thermal runaway of the canister temperature due to a failure of the thermostat, a thermal fuse 59 which is mounted to the bottom member 44 and thus in thermal communication thereto is also configured in a series connection with the heater element 57 to create an electrically open circuit if the temperature of the canister goes above a predetermined temperature, preferably about 450 degrees Fahrenheit. The heater element 57 , thermostat 58 , and thermal fuse 59 define an electrical circuit which terminates in an electrical cord (not shown) for connection to a suitable source of electrical power.
The neck member 42 has a valve body 62 integrally formed therein to provide for selective communication of the steam from the canister to the steam tube 64 . The valve body 62 has an aperture 66 disposed at its lower end in order to provide fluid communication from the canister 41 into the valve body 62 . Steam flow through the aperture 66 is regulated by a valve pin assembly which is slidably received in a hollow shaped plug 67 having an o-ring 68 disposed therebetween to prevent the leakage of steam therethrough. The upper end of the inner wall of the valve body 62 is threaded to threadably receive the plug 67 wherein the head 69 thereof is hexagonally shaped in order to facilitate insertion via a conventional wrench. The valve pin assembly generally includes a pin head 71 which is screwably connected to a connecting rod 72 having a seat flange 73 attached at its lower extremity. A thermally resistant valve seat 74 which is attached to the bottom surface of the seat flange 73 using any suitable adhesive is springably biased against the aperture 66 via compression spring 75 . Thus, communication of the steam through the valve is inhibited when no external force is placed upon the pin head 71 . Conversely, when a generally upward directing force acts on the pin head 71 , the valve is opened and steam is allowed to flow freely from the canister to the steam tube 64 . A tube-shaped projection 78 is integrally attached to the neck member 42 having an aperture 79 therebetween, wherein projection 78 has threads on its inner surface to threadably receive the steam tube 64 therein. The steam tube 64 is preferably made from a thermoplastic material such as polypropylene to minimize the amount of heat conduction to the outer perimeter thereof due to hot steam passing therethrough.
Integrally formed with the neck member 42 is a fill tube 81 which extends vertically thereabove. The fill tube 81 extends slightly above the bottom wall of a cup-shaped depression 25 and is held in place with a snug water-tight fit with a grommet 82 therebetween. The depression 25 is integrally attached to the upper wall 11 of the housing having a predetermined diameter to accommodate the bottom edge of the pressure safety cap 85 with an air gap 83 therebetween. The fill tube 81 has internal threads to threadably receive the external threads of the safety valve portion 86 of the pressure safety cap 85 . The safety valve portion 86 generally comprises a cylindrical pressure relief housing 87 made preferably of brass, having a generally disk-shaped member 88 integrally attached thereto. An o-ring 84 which extends around the periphery of the housing 87 and abuts member 88 thereunder serves to prevent the leakage of steam past the housing 87 . The bottom end of pressure relief housing has a seat having an aperture 90 therein for receipt of a small ball valve member 89 which is springably biased to the closed position. A compression spring 91 exerts a downward force on ball member such that when the internal pressure within the canister exceeds a predetermined pressure, preferably less than 15 psi, the steam may be vented therefrom. Vent holes 93 disposed in member 88 allow the steam within housing 87 to pass through to the ambient environment. The pressure safety cap 85 also comprises a shroud portion 95 for hand screwing of the valve portion to and from the fill tube 81 . The shroud portion 95 comprises a generally inverted cup-shaped member 96 made of any material, preferably polypropylene, having an annular-shaped valve mount member 97 integrally attached thereto for securement of the safety valve portion 86 via a press fit.
Manual control of the jet of steam is provided by a valve actuator button 100 disposed within a rectangular shaped hole 101 in the upper wall 11 proximate the rear edge thereof in conjunction with a rocker arm 107 . The valve actuator button 100 constructed of any material, preferably plastic, comprises a body portion 102 having two arms 103 which depend downward from and are integrally attached thereto as best shown in FIGS. 8 and 9 . Both of the arms 103 have holes 104 formed therein for receipt of a pintle bolt 105 therethrough. The rocker arm 107 acts to translate the vertically directing downward force of the button 100 to a generally upward directing force on the pin head 71 of the valve pin assembly via fulcrum member 116 . The rocker arm 107 is comprised of a an elongated section of sheet metal having a generally inverted U-shaped cross-section defining top 108 , and side walls 109 which terminate at proximal 112 and distal 113 ends. The top wall 108 has a circular shaped hole 115 formed therein through which the fill tube 81 extends. Two fulcrum members 116 depend from and are integrally attached to each of the side walls 109 which rest upon the surface of the neck member 42 thereby allowing the rocker arm 107 to pivot about its axis. Holes 118 exist in each side wall 109 proximate the proximal end 112 thereof for providing a rotatable connection to the arms 103 of button 100 via bolt 105 . Similarly, holes 120 exist in each side wall 109 proximate the distal end 113 thereof for providing a rotatable connection the pin head 71 via bolt 121 . Thus, when a downward force on the button 100 is applied by a user, the button consequently rotates the rocker arm 107 about fulcrum member 116 and lifts the valve pin assembly thereby opening the valve.
To use, the pressure safety cap 85 is temporarily unscrewed from the device 10 and a predetermined volume of water which is less than the maximum water holding capacity of the canister is poured into the canister 41 via the fill tube 81 . It is to be understood that the maximum water holding capacity is slightly less than the absolute volumetric capacity of the canister so that the water level does not extend above the aperture 66 of the valve body 62 . Next, the pressure safety cap 85 is screwed onto the fill tube 81 and the electrical cord connected to a suitable source of electrical power. As electrical power is applied to the heater element 57 , the steam generated thereby raises the pressure within the canister to a level which is maintained in equilibrium by the thermostat 58 . When equilibrium of the steam/water mixture has been achieved, the device 10 is ready to use. A jewelry piece is placed within the cleaning zone 17 using tongs 27 and the actuator button 100 pressed by a user thereby causing a jet of steam to be emitted from the tube 64 and enveloping the jewelry piece to be cleaned. Failure protection mechanisms include a pressure safety valve which automatically releases steam from the canister 41 if the internal pressure of the canister exceeds a predetermined level and a thermal fuse 59 which automatically opens the circuit to the heater element 57 if the temperature exceeds a predetermined level.
The present invention may be embodied in other specific forms without departing from the spirit or scope of the invention. For example, although the present disclosure described a means of cleaning jewelry, is well known in the art that other small items may be cleaned by immersion in the jet of steam such as coins, trinkets, or the like. Therefore, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A jewelry cleaning device which emits a jet of steam under manually operable control means for the cleansing of various types of small items including jewelry, coins, trinkets, or the like. The jewelry cleaning device of the present invention is lightweight and relatively compact in size thus enabling its use on virtually any conventional tabletop and is easily stored when not in use. The steam generator is powered by conventional electrical power and is controlled by means of a thermostat to maintain the water/steam mixture at a predetermined temperature while in operation. Safety mechanisms include a pressure relief valve to automatically expel steam from the generator when the internal pressure thereof exceeds a predetermined level and a thermal fuse configured in a series connection with the heating element of the steam generator. A containment device is optionally provided which is made of screen mesh and fashioned into a cup-like shape, is slidably engaged onto the sidewall of the jewelry cleaning device housing and is disposed underneath the spout in such a manner to trap gems or other small parts which are inadvertently dislodged from the jewelry piece during the cleaning operation. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to reducing the color forming tendencies of certain esters and, more particularly, to the treatment of methyl esters with an alkali metal methylate.
2. Description of the Prior Art
U.S. Pat. No. 3,642,871 issued on Feb. 15, 1972 discloses the use of an alkali metal alkoxide, e.g., sodium methylate necessarily combined with phosphorus atoms, e.g., phosphoric acid to improve the color stability of a wide variety of organic esters including diesters of aliphatic carboxylic acids, e.g., dimethyl adipate, dibutyl sebacate and diisopropyl succinate.
SUMMARY OF THE INVENTION
A process for reducing the color forming tendency of alkanedioic acid methyl esters, e.g., those esters derived from dicarboxylic acids having 4-12 carbon atoms which comprises, consists or consists essentially of contacting the esters with alkali metal methylate, preferably sodium methylate.
DETAILED DESCRIPTION OF THE INVENTION
The methyl esters to which the present invention is particularly applicable are those prepared from the acids isolated as co-products from the air oxidation of cyclic hydrocarbons to cyclic ketones and alcohols followed by the oxidation of the ketones and alcohols with nitric acid. The oxidation of cyclohexane to cyclohexanol and cyclohexanone can be conducted according to the teachings, for example, of U.S. Pat. No. 3,530,185 issued on Sept. 22, 1970. Cyclohexanol and cyclohexanone produced according to the aforementioned Patent are then oxidized with nitric acid according to the teachings of U.S. Pat. No. 3,359,308 issued on Dec. 19, 1967 and U.S. Pat. No. 3,365,490 issued on Jan. 23, 1968. Illustrative of the co-product acids that are produced along with adipic acid in the aforementioned processes are succinic acid and glutaric acid.
The preparation of alkane dicarboxylic acids having from 8 to 12 carbon atoms by the nitric acid oxidation of the corresponding alcohols and ketones is disclosed in U.S. Pat. No. 3,758,564 issued on Sept. 11, 1973. Illustrative of the co-product acids produced in this process are pimelic acid, suberic acid, azelaic acid, sebacic acid and undecanedioic acid.
The principal acids produced in the above described processes, i.e., adipic acid and dodecanedioic acid are commonly separated from the co-product acids by crystallization and the co-product acids then recovered from the mother liquor by known methods. These co-product acids can be converted to esters by known esterification processes. Even after rigorous distillation, these esters still exhibit a marked tendency to turn yellow when subjected to alkaline conditions or when heated to temperatures for which the esters are eventually employed, e.g., for the preparation of other esters and polyesters by transesterification.
The color-forming tendency of esters which are treated according to the process of the present invention is believed due to the presence of small amounts of aliphatic nitro compounds which form during the nitric acid oxidation of the ketones or alcohols and/or during acid catalyzed esterification in the presence of residual nitrate ion. These impurities co-distill with the esters; are not adsorbed to any significant extent on activated carbon and are not amenable to bleaching, e.g., with peroxides or aqueous hypochlorites.
The methylates which are operable in the present invention include sodium, potassium and lithium methylate and mixtures of the foregoing. Sodium methylate is preferred.
The method for contacting the methylate with the esters is not critical to the present invention. Adding the solid methylate to the esters with low shear stirring at ambient temperature has been found completely satisfactory. As one skilled in the art can appreciate, elevated temperatures will accelerate the reaction. The contacting may be conducted at temperatures up to 225° C. and preferably 75°-100° C. for times varying from about 0.5-2 hours. Time can be decreased as the temperature is increased. The presence of water markedly reduces the effectiveness of the methylate and it is preferred to maintain water at the lowest practical level, e.g., less than 0.1% by weight based upon the weight of the esters.
The esters should be neutral or slightly basic for optimum utilization of the methylate and for color reduction. Usually a precipitate is formed during the contact of the ester and the methylate which can if desired be removed by known methods, e.g., filtration before further processing of the treated esters.
The amount of methylate required will, of course, depend upon the amount of color-formers present which is dictated by the conditions used in preparing the acids and/or the esters. It has been determined that 2-25 and usually about 5 parts by weight of methylate per 1000 parts by weight of ester is usually sufficient for complete reduction in color. In many instances less than one part of methylate per 1000 parts of ester can accomplish complete color reduction. In any event, the amount of methylate required is readily determined by increasing or decreasing the amount of methylate until the desired level of color is obtained. Excess methylate can be employed to assure an essentially complete reduction in color forming tendency.
The following examples are presented to illustrate but not to restrict the present invention. Parts and percentages are by weight unless otherwise specified. The color forming tendencies of the esters treated according to the process of the present invention were determined by adding two drops of a 40% by weight solution of benzyltrimethyl ammonium-hydroxide in methanol to 5 ml of esters, followed by shaking the solution. The esters reported in the Examples were treated in this manner before determining the color. Color was judged using a Hellige Color Comparator equipped with a Gardner color disc (color system of the Institute of Paint and Varnish Research). This technique measures the yellowness of samples on a scale from 1 (very light yellow) to 10 (dark yellow). A colorless sample exhibits a Gardner color of less than 1.
EXAMPLE 1
To a 500 ml flask fitted with a simple distillation head and suitable heating equipment was added 227 grams of the mixed methyl esters of succinic, glutaric and adipic acid, having the analysis set forth in Table I and a Gardner color of 4.
TABLE I______________________________________Dimethyl succinate 2%Dimethyl glutarate 71%Dimethyl adipate 27%______________________________________
This ester mixture was prepared as described hereinabove by esterification of the acids obtained by the nitric acid oxidation of a mixture of cyclohexanol and cyclohexanone followed by removal of the majority of adipic acid by crystallization.
Approximately 3.5 grams of sodium methylate was introduced into the flask. The resultant slurry was heated with stirring at 75° C. for one hour whereupon the contents of the flask turned yellow. This ester was then distilled with essentially no fractionation under 25 mm Hg vacuum. Approximately 215 grams of distillate having a Gardner color of <1 was collected.
EXAMPLE II
A mixture of C 7-12 straight chain dibasic acids recovered from the nitric acid oxidation of cyclododecanone and cyclododecanol as described hereinabove were esterified with methanol using a dodecylbenzene sulfonic acid catalyst. The resultant esters were then distilled under 1 mm Hg pressure and a distillate boiling in the range of 95°-140° C. and having a Gardner color of 9 was recovered. This ester distillate had the composition given in Table II.
TABLE II______________________________________Dimethyl pimelate 0.5% Dimethyl sebacate 7.5%Dimethyl suberate 1.5% Dimethyl undecandioate 48.4%Dimethyl azelate 4.2% Dimethyl dodecandioate 37.9%______________________________________
To 124 parts of the ester distillate was added 2 parts of sodium methylate with mild agitation at room temperature. The mixture was then distilled at <1 mm Hg pressure. After a small foreshot which was discarded, 104 parts of treated esters were collected which had a Gardner color of less than 1. | Process for reducing the color forming tendency of alkanedioic acid methyl esters by contact with an alkali metal methylate. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The object of the invention is a security feature and a corresponding proof process for security documents, which process is based on the piezo effect.
2. Description of the Related Art
Hitherto there has been merely known the practice of applying the security features to security documents and documents of value in the form of particles, these particles having been formed as electro-luminescence elements. Such electro-luminescence elements react in an electromagnetic alternating field, as they emit a given light. A precondition for this security feature, to be sure, is the applying of an external electromagnetic field, which is associated with relatively high expenditures. Furthermore, the application range of these security and value documents provided with EL particles is restricted to the condition that only a light of a given wavelength is emitted.
Underlying the invention, therefore, is the problem of further developing security and value documents of the type mentioned at the outset in such manner that a further security feature can be added. The use purpose of such a document is therewith to be extended. Besides the optical detection of security features there is further to be made possible a detection in another frequency range. An additional feature of the present invention lies in that a process is described for the detection of this security characteristic.
BRIEF SUMMARY OF THE INVENTION
The solution of the first problem occurs essentially through the feature that the value and security document is equipped with piezo-electric properties.
The solution of the second problem occurs essentially by the means that the value and security document is exposed to the signals, in which the piezoelectric properties are utilized. The signals given off from the piezo elements are thereupon detected and evaluated.
In a preferred embodiment of the invention it is provided that the piezoelectric properties of this value and security documents were introduced onto or into the document in the form of piezo material.
If value and security documents or other relevant products are equipped with piezoelectric security features, then these can be mechanically excited (for example by impacts or acoustically) or optionally electrically, and their answers can be detected and evaluated. From the system answer of the value and security document it is possible to infer the materials used and their geometrical dimensions. A comparison of test piece and reference sample makes possible a distinguishing of genuine and forged value papers or products.
The equipping of relevant products with piezoelectric security features can occur in the following manners:
piezoelectric micron particles are admixed to the printing inks or other application layers,
piezoelectric micron particles are admixed to the base material of the security product (for example paper, foils, glass) during the production,
metallized piezo-polymer foils in the micron range are applied as intermediate product and/or layer in or onto the value paper/product (gluing, laminating, laser welding etc.), or
piezo ceramic platelets are laminated in with thicknesses of much less than 100 microns.
As micron particles there are designated elements the geometric dimensions of which lie in the range of microns.
Excited with impulses, the piezo elements react with vibrations which again are electrically or mechanically (acoustically) transferred and can be suitably evaluated. Especially the natural frequencies of these vibrations are a highly significant characteristic for types of materials used and their geometric dimensions. As additional information parameters there can be evaluated the signal damping (FFT) of a transmitted signal.
In the invention therefore both the piezo effect and also the reciprocal piezo effect is drawn upon for the evaluation.
Thus there is obtained with the frequency spectrum according to reception signal scanning and FFT, a sort of “Fingerprint” of the value paper or product.
In a preferred embodiment of the present invention there is provided that in such a value and security document there are embedded piezo-electrically active particles. Here it is not a matter of the grain size and the type and the arrangement of these particles in detail. They can be either uniformly embedded into the material of the value and security document, in which case, however, they could be heaped up in certain places of the value and security document.
In another embodiment they can be applied to the surface of the value and security document, (and be embedded into the document on the surface, or they can additionally be covered by means of a covering layer, a lacquering, a plastic covering or a lamination foil.
In a further embodiment of the invention it can be provided that instead of using individual particle-form piezo materials, a piezo effect may also be produced in a polymer foil.
As an example for such a polymer foil there is to be mentioned a PVDF foil.
Instead of the use of individual piezo particles that are applied in uniform or non-uniform form to or on a value or security document it is possible in another embodiment to sinter such elements, especially in crystal structure, in order to create from them a larger piezo element. Also such a larger piezo element can be embedded—as stated earlier—either on the surface or at the surface of the value and security document or also embedded in the surface.
What is important in the invention is that to the first mentioned security feature known per se, i.e. the emitting of a certain light spectrum, there is now allocated a further security feature which can act standing alone or in connection with other security features. In the corresponding excitation of the piezo material mentioned, therefore, a vibration answer is generated to a corresponding mechanical or acoustical excitation of the piezo material.
On mechanical loading of certain crystals, such as, for example, quartz, tourmaline, Seignette salt in given directions to the crystal axes there occur, namely, electrical displacements, consequently free surface charges, which are proportional to the generating force. This piezoelectric effect is suited as the basis for the security feature described here. The preferably used quartz crystallizes in hexagonal prisms. Correspondingly to its atomic structure it has 3 polar electric axes, 3 mechanical neutral axes and one optical axis standing perpendicularly to these. From the crystal then, parallel plates are cut out, which are suitable as feelers.
If these are pressed in X- or Y-direction, then there arises on the X-Z surfaces the charging of the piezo module.
The invention is not restricted, however, to the use of mono-crystalline crystals, but—as indicated earlier—crystal agglomerates can be used, or also sintered crystals.
Instead of such crystals ceramic bodies can also be used, which are likewise known to have a piezoelectric effect.
The excitation of such a piezo material occurs preferably with an acoustic or electric impulse. Likewise the excitation can occur with a signal source in which all the frequencies are present, which, therefore generates a wide-band, white noise.
Instead of these excitation mechanisms the excitation can also occur by means of a laser impulse.
The vibration answer of the piezo material occurs in the sense of a natural frequency of this material. If, therefore, excitation is performed with a single impulse, this piezo material is excited up to free-running vibration and it vibrates over a certain impulse duration with a natural frequency which can be detected and evaluated outside of the security and value document. The frequency of the vibration answer lies here in the kilohertz up into the gigahertz range and can be picked up and evaluated with corresponding measurement value receivers.
Preferably, therefore, for the vibration stimulation a single impulse generator is used, which, therefore, mechanically delivers a single impulse onto the value and security document to be tested and with corresponding measurement value receiver technique, then, the vibration answer is detected and evaluated.
Here it is important that always the total system of the value and security document is checked. If, therefore, for example adhesive additives, material denudation fragments or other (also local) attacks were made on the document, then therewith (also locally limitedly) the system-answer of the total system is displaced.
In another embodiment a continuous excitation can occur by means of a white noise which is delivered to the value and security document over a corresponding vibration generator.
Likewise the excitation of the value and security document can occur in feedback operation, i.e. a certain excitation frequency is used; the answer frequency is then investigated and fed back onto the excitation frequency, in order in this way to obtain a vibration excitation and to excite the piezo material in the range of its resonance frequency.
The type of resonance frequency is then an image of the vibration property of the piezo material, and is therewith characteristic as a fingerprint for the security feature which is accommodated in the security document. It is a matter here of a peak pattern which is generated not at a single characteristic frequency, but in a certain frequency band.
The resonance frequency is dependent on the geometry of the individual piezo grain. The effects described earlier obviously serve in a like manner for the piezo electric foil already described, the PVDF foil which is excited in the same manner and that generates a corresponding vibration answer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
All the indications and features disclosed in the documents, inclusive of the abstract, especially the spatial design represented in the drawing, are claimed as essential to the invention insofar as they are novel individually or in combination with respect to the state of the art.
In the following the invention is explained in detail with the aid of drawings representing only one course of execution. Here there proceed from the drawings and their description further essential features and advantages of the invention.
In the drawing:
FIG. 1 shows schematically a section through a value document in a first form of execution with representation of the evaluating unit,
FIG. 2 : two half-sections through a value and security document with two different examples of execution for the application of the piezo material,
FIG. 3 : the explanation of the mechanical functioning of the piezo material on its excitation,
FIG. 4 : a form of execution modified with respect to FIG. 3 in which the piezo material is stimulated by means of an impulse,
FIG. 5 : a section through a value document with piezoelectric properties laminated in card form,
FIG. 6 : the enlarged section through a piezo element with individual piezo crystals.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is represented in general a value document 1 , in which a piezo material 2 is embedded. The embedding here can occur in the paper manufacture, so that the piezo material is embedded into the material of the paper in the form of individual granulates, grains, crystal structures and the like.
Obviously the value document 1 does not have to consist of a paper material; it can also be a plastic, a multiply laminated plastic or any arbitrary other material, into which the piezo material is embedded.
It is represented that by means of an excitation 3 the piezo material 2 is acted upon, which then answers with a corresponding vibration answer 4 , which is received by a vibration receiver 5 .
The vibration receiver 5 can be constructed here as a microphone; i.e., the vibration answer is an acoustic wave which is received by the vibration receiver 5 . Consequently, the vibration receiver 5 can itself also be constructed as a crystal or piezo-crystal microphone.
It can, of course, also be emplaced directly on the document, so that depending directly on the value document itself, a further piezo vibration receiver is emplaced, which receives the vibration answer 4 from the piezo material 2 and evaluates it correspondingly. In the example of execution shown, the vibration receiver 5 is connected with an amplifier 6 that for its part is connected with a frequency analyzer 7 , which spectrally evaluates the vibration answer 4 . The frequency analyzer 7 is then connected with a display device which then generates a true/false announcement.
In FIG. 2 it is represented that the piezo material 2 can also be applied directly to the surface of the value document 1 and can be connected with this value document 1 in arbitrary manner.
The right half-section in FIG. 2 shows that the piezo materials 2 can also be covered with a corresponding coating 9 . The coating 9 can be formed here as lacquer, as foil, as printing ink or the like.
They can also protrude in part from the coating 9 .
In FIG. 3 there is presented the general principle of the piezo crystal. It is evident that in the mechanical equivalent two printing plates 10 , 11 can act from both sides on the piezo material 2 and here one printing force 12 , 13 acts in each case on one printing plate 10 , 11 . Obviously, the invention is not restricted to this; the printing plate 11 and the appertaining printing (or pressure) force 13 can be entirely omitted, because, after all, the applying of a force from above over a corresponding vibration generator fully suffices, since, after all, the piezo material 2 is embedded on a solid or in a solid substrate.
In this equivalent circuit diagram according to FIG. 3 it is supposed to be represented that by reason of the introduction of vibrations the piezo material begins to vibrate in the arrow directions 14 and here there occurs a corresponding surface charging 15 , 16 , which is always pole-reversed, so that—according to FIG. 4 —then by reason of the pole-exchanging surface charges 15 , 16 there occurs a vibration emission, i.e., therefore, a vibration answer 4 .
This is represented better in FIG. 4, where it is evident that the excitation 3 is applied either as a sole impulse, as excitation by means of a certain excitation frequency (therefore continuous excitation) or as white noise, and here by reason of the pole reversal in the arrow directions 14 the vibration answer 4 is generated.
In FIG. 5 there is presented the technology of a value and security document in the construction as a value card 17 .
Such a value card can be a pass card, a personal identification, a driver's license or another security or credit card.
Here it is represented that an upper laminate layer 19 is present, which covers a piezo-electrically active foil (piezo foil 18 ). This piezo foil is a polymer foil that has piezoelectric properties. If, accordingly, an excitation 3 is initiated onto the piezo foil 18 , the latter answers with a vibration answer 4 which can be evaluated correspondingly by an evaluating unit according to FIG. 1 .
Besides the evaluation according to an evaluating unit according to FIG. 1, however, the evaluation can also occur by two capacitor plates 24 , 25 which take up between them the value card 17 . After the vibration answer 4 alters the dielectric between the capacitor plates 24 , 25 , a corresponding measuring arrangement which measures the impedance between capacitor plates 24 , 25 can be drawn upon to evaluate the vibration answer 4 .
Obviously it is also possible to pick up the charge displacement which is yielded on the upper side and under side of the piezo foil 18 directly. Here, after all, it is not necessary for the solution that the piezo foil 18 be enclosed in the laminate structure; it can also be present directly on the surface or partly on the surface in order to permit a corresponding contacting.
In the example of execution it is further represented that underneath the piezo foil 18 there can be arranged a substrate layer 20 , which again is covered downward by a laminate layer 19 .
FIG. 6 shows that also larger piezo elements 21 can be created, which consist of a collection of piezo crystals 23 which, for example, are sintered with one another by a sintering process. It is a matter, therefore, of a piezo crystal.
Likewise the individual piezo crystals 23 can be bound in a carrier substance 22 which is, for example, a plastic.
Besides the excitation by an impulse- or sound-source 3 , still other excitation mechanisms can also be used, especially also evaluation mechanisms. It was indicated earlier that the vibration answer 4 is evaluated by corresponding receivers. Instead of the evaluation of the frequency of the vibration answer, however, also the response time can be detected. If, namely, the time point of the vibration excitation is known, there is only needed, still, to measure at which time point the vibration answer 4 is measurable on the measuring value receiver 5 , in order in this way to make possible a response time measurement. Instead of the frequency evaluation, therefore, instead of this, a response time measurement can be carried out. With this response time measurement it is further possible, incidentally, to state the exact position (depth of the piezo materials) in the value document to be checked, because, after all, the response time of the vibration answer is a measurement for the depth at which the piezo material 2 is embedded in the document.
After the vibration answer 4 has also been altered by the layers lying above and below in the value document, it is also possible, by the evaluation of the damping of the vibration answer, to infer the materials lying underneath and above.
LEGENDS FOR DRAWINGS
1 Value document
2 Piezo material
3 Excitation 3 a
4 Vibration answer
5 Vibration receiver
6 Amplifier
7 Frequency analyzer
8 Indicating device
9 Coating
10 Printing plate (or Pressure plate)
11 Printing plate (or Pressure plate)
12 Pressure force
13 Pressure force
14 Arrow direction
15 Surface charge
16 “ ”
17 Value card
18 Piezo foil
19 Laminate layer
20 Substrate layer
21 Piezo element
22 Carrier substance
23 Piezo crystals
24 Capacitor plate
25 “ ” | A security feature is provided for value and security documents in the form of piezo security particles. Electrical and mechanical properties of the piezo-security particles are utilized to detect and evaluate the security feature of the value and security document. | 6 |
This application is a continuation of application Ser. No. 07/617,175 filed Nov. 23, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compound semiconductor devices and more particularly, to formation of a contact to an n type Al x Ga 1-x As (0≦×≦1) material.
2. Description of the Related Art
GaAs has been considered to offer a very promising prospect as a material for a high speed device, because the material has a mobility of about 6 times larger than that of silicon (Si) and can be easily made into a semi-insulating substrate.
Al x Ga 1-x As obtained by adding aluminum (Al) to GaAs is very close in lattice constant to GaAs and allows good epitaxial growth with GaAs. For this reason, attention has been increasingly directed to development of heterojunction devices based on an Al x Ga 1-x As/GaAs heterojunction.
As a result, many sorts of devices have been developed, including, for example, an Al x Ga 1-x As/GaAs heterojunction bipolar transistor (HBT) having a wide gap emitter of Al x Ga 1-x As, and a high electron mobility transistor (HEMT) having an electron supply layer of Al x Ga 1-x As.
For the purpose of enhancing the performances of these devices, it is very important to reduce the resistance of their ohmic contact.
Generally speaking, it is difficult to form an ohmic contact of low resistance on an Al x Ga 1-x As layer (0<×≦1). For this reason, even when such an Al x Ga 1-x As layer must be placed as the top layer of a device, an n + type GaAs layer has been formed on the Al x Ga 1-x As layer as a cap layer for the ohmic contact. To this end, the composition of metal material of its electrodes, the temperature of heat treatment for the formation of the alloy, etc., have been correspondingly devised.
Since these GaAs and Al x Ga 1-x As materials are large in band gap and low in the upper limit of obtained electron concentration when compared with Si material, the reduction of the ohmic contact resistance is limited thereby.
To overcome this, there has been proposed a method of using In x Ga 1-x As material having a band gap smaller than the Al x Ga 1-x As or GaAs as a contact layer (refer to J. Vac. Sci. Technol., 19 (3), 1981, pp626-627).
FIG. 5 shows, as one of such prior art examples, an ideal energy band between an n type GaAs layer and a metallic electrode with an n + type In x Ga 1-x As layer and an n + InAs layer interposed therebetween at the time of forming a contact to the n type GaAs. For the purpose of smoothly connecting together the bands of the GaAs and InAs layers, the graded-composition layer of the In x Ga 1-x As material (x=0→1) is inserted between the GaAs and InAs layers. Since no Schottky barrier is present between the InAs layer and the electrode, a low resistance contact can be obtained.
However, there is a lattice misalignment as large as about 7% between the InAs and GaAs layers.
This lattice misalignment causes the InGaAs layer to be subjected to a misfit dislocation. In the event where the thickness of the InGaAs layer is below its critical thickness, no misfit dislocation takes place. When it is desired to form an ohmic contact of lower resistance, however, it is preferable that an In mixed crystal ratio x is closer to 1 and the critical thickness becomes correspondingly smaller. When the InGaAs layer has a mixed crystal ratio x of 0.5, its critical thickness is below several ten Å. In addition, as the mixed crystal ratio x is closer to 1, the thickness of the In x Ga 1-x As graded-composition layer necessary for smoothly connecting the bands of the InAs and GaAs layers is larger. Meanwhile, when the element performance, process, etc., are taken into consideration, it is preferable to make small the thickness of the contact layer. From these reasons, when an ohmic contact of low resistance is to be formed with use of a practical structure, the occurrence of a misfit dislocation cannot be avoided.
Furthermore, the occurrence of such a misfit dislocation is concentrated, in particular, in the In x Ga 1-x As as an intermediate layer to compensate for the carriers in this area, which involves a problem that the carrier concentration is reduced.
It is known that the upper limit of the usual carrier concentration, which depends on the epitaxial growth conditions and so on, is about 2×10 19 cm -3 and about 1×10 19 cm -3 for InAs and GaAs respectively. In the case of the InAs/In x Ga 1-x As/GaAs structure, a large carrier concentration dip occurs, in particular, in the intermediate layer of In x Ga 1-x As. When the thickness of the In x Ga 1-x As is made sufficiently large, the dislocation density (cm -3 ) is also reduced and the carrier concentration dip is correspondingly decreased.
When consideration is paid to the application of such a structure to a semiconductor device having an n type ohmic contact, however, it is not practical to increase the layer thickness.
Turning now to FIG. 6, there is shown a measurement result of carrier concentration distribution in the InAs/In x Ga 1-x As/GaAs structure doped with silicon. In the drawing, the film thickness of the In x Ga 1-x As layer was set to be 500Å and 1.5×10 19 cm -3 of silicon was doped into the InAs and In x Ga 1-x As. As will be seen from the drawing, the carrier concentration largely drops in the In x Ga 1-x As layer and there is an area therein where the carrier concentration is substantially zero especially in the vicinity of the interface with the GaAs layer. Under such a condition, the contact resistance when a current x flows in a vertical direction with respect to the semiconductor layer was as high as 5×10 -6 Ω cm 2 .
Thus, the conventional structure has had such a problem that, even when a low-resistance contact can be obtained at the InAs/electrode interface, it is impossible for the entire contact to have a sufficiently low resistance.
In this way, the conventional method of forming the ohmic contact to the n type GaAs layer using the In x Ga 1-x As layer has had a problem that the carrier compensation caused by the misfit dislocation causes the reduction of the carrier concentration, which results in that an area having a high resistance is formed and the contact resistance becomes correspondingly large.
SUMMARY OF THE INVENTION
In view of the above circumstances, it is an object of the present invention to realize an ohmic contact having a very low resistance, which can avoid such a problem in the prior art that, at the time of forming an ohmic contact to an n type GaAs layer using an In x Ga 1-x As layer, reduction in the carrier concentration of the In x Ga 1-x As graded-composition layer causes formation of a high-resistance layer.
According to the present invention, in forming a metal electrode layer on an n type Al x Ga 1-x As layer via an In x Ga 1-x As graded-composition layer and an In x Ga 1-x As contact layer having a constant composition, the In x Ga 1-x As graded-composition layer doped with an n type impurity which concentration is higher than a concentration of an impurity to be activated as n type is used.
And desirably, a carrier concentration of an area within the In x Ga 1-x As graded-composition layer which area is contacted with the In x Ga 1-x As contact layer is set higher than a carrier concentration of an area therewithin which area is contacted with the Al x Ga 1-x As layer.
Further, preferably, an n type impurity concentration of an area within the In x Ga 1-x As graded-composition layer which area is contacted with the In x Ga 1-x As contact layer is set higher than an n type impurity concentration of an area therewithin which area is contacted with the Al x Ga 1-x As layer.
The inventors of the present application have studied and conducted many tests on the basis of measurement results of carrier concentration distribution in such an InAs/In x Ga 1-x As/GaAs structure doped with silicon as shown in FIG. 6, and eventually found the fact that, when the amount of n type impurity doped into the In x Ga 1-x As graded-composition layer is set to be remarkably large, a large dip or drop in the carrier concentration within the composition layer can be eliminated.
The present invention is based on this fact.
That is, in accordance with the present invention, the In x Ga 1-x As graded-composition layer is doped with an n type impurity which concentration is higher than an n type-activated impurity concentration so that, even when a current is vertically passed through the semiconductor device, a very low contact can be attained.
In this case, when a carrier concentration of an area within the In x Ga 1-x As graded-composition layer which area is contacted with the In x Ga 1-x As contact layer is set higher than a carrier concentration of an area therewithin which area is contacted with the Al x Ga 1-x As layer, the contact resistance can be further reduced.
Further, when an n type impurity concentration of an area within the In x Ga 1-x As graded-composition layer which area is contacted with the In x Ga 1-x As contact layer is set higher than an n type impurity concentration of an area therewithin which area is contacted with the Al x Ga 1-x As layer, the carrier concentration within the graded-composition layer can be increased and the contact resistance can be much more reduced.
From our experimental results, it is desirable that the impurity concentration is set to be above 3×10 19 cm -3 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a heterojunction bipolar transistor in accordance with a first embodiment of the present invention;
FIG. 2(a) is a graph showing a relationship between n type impurity concentration and depth for respective layers of an emitter contact portion in the transistor of FIG. 1;
FIG. 2(b) is a graph showing a relationship between carrier concentration and depth for the same layers;
FIG. 3(a) is a graph showing a relationship between n type impurity concentration and depth for respective layers of an emitter contact portion in a transistor in accordance with a second embodiment of the present invention;
FIG. 3(b) is a graph showing a relationship between carrier concentration and depth for the layers in the same transistor;
FIG. 4(a) is a graph showing a relationship between n type impurity concentration and depth for respective layers of an emitter contact portion in a transistor in accordance with a third embodiment of the present invention;
FIG. 4(b) is a graph showing a relationship between carrier concentration and depth for the layers in the same transistor;
FIG. 5 shows an ideal energy band for a structure of an n type GaAs layer, n + type In x Ga 1-x As layer and an InAs electrode; and
FIG. 6 is a graph showing a relationship between carrier concentration and depth for respective layers of a conventional n type GaAs/n + type In x Ga 1-x As/InAs electrode structure doped with silicon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown, in cross section, a heterojunction bipolar transistor which is based on AlGaAs/GaAs heterojunction in accordance with the present invention.
The heterojunction bipolar transistor shown in FIG. 1 includes a collector contact layer 2 formed on a semi-insulating substrate 1, a collector layer 3, which may be formed of an n type GaAs material, formed on collector contact layer 2, a base layer 4, which may be formed of a p type Al x Ga 1-x As material where 0≦×<1, formed on collector layer 3, a constant-composition emitter layer 5, which may be formed of an n type Al x Ga 1-x As material where 0≦×≦1, formed on base layer 4, and a graded-composition emitter layer 6, which may be formed of an n type Al x Ga 1-x As material where 0≦×≦1, formed on constant-composition emitter layer 5. An emitter contact formed on graded-composition emitter layer 6 includes an Al x Ga 1-x As constant-composition layer 7 where 0≦×≦1, an In x Ga 1-x As graded-composition layer 8 where 0≦×≦1, and an In x Ga 1-x As constant-composition contact layer 9 where 0<×≦1. A metal electrode 10 is formed on an In x Ga 1-x As constant-composition contact layer 9.
Specific embodiments of the present invention will be discussed in detail with reference to the attached drawings.
EMBODIMENT 1
The illustrated heterojunction bipolar transistor is characterized in that a contact to an emitter layer made up of an n type Al 0 .3 Ga 0 .7 As layer 5 of 2000 Å thickness and an n type Al x Ga 1-x As graded-composition layer (x=0.3→0) 6 of 300 Å thickness comprises an n + type GaAs layer 7 of 500 Å thickness, an n + type In x Ga 1-x As graded-composition layer (x=0→1) 8 of 400 Å thickness and an n + type InAs layer 9 of 400 Å, and in that the n + type InAs layer 9 and n + type In x Ga 1-x As layer 8 are set to have both a high impurity concentration of 3.5×10 19 cm -3 and an emitter electrode 10 of Cr/Au material is formed on the n + type InAs layer 9. In this case, the measured impurity concentration of the n + type In x Ga 1-x As layer 8 is 3.5×10 19 cm -3 as shown in FIG. 2(a). Si is used as the n type impurity and Be is used as the p type impurity.
More specifically, in the heterojunction bipolar transistor, its element region includes an n + type GaAs layer 2 of 5000 Å thickness formed on a semi-insulating GaAs substrate 1 as a collector contact layer, an n - type GaAs layer 3 of 5000 Å as a low-concentration collector layer, a p + type GaAs layer 4 of 1000 Å as a base layer, the n type Al 0 .3 Ga 0 .7 As layer 5 of 2000 Å forming the emitter layer, and the n type Al x Ga 1-x As graded-composition layer (x=0.3→0) 6 of 300 Å, these layers being sequentially formed in this order. The contact to the emitter layer includes the n + type GaAs layer 7, the n + type In x Ga 1-x As graded-composition layer (x=0→1) 8 and the n + type InAs layer 9.
The emitter, base and collector electrodes 10, 11 and 12 are provided to the corresponding layers respectively.
The respective semiconductor layers of this heterojunction bipolar transistor are formed on the substrate by one of a number of possible epitaxial growth techniques including a molecular beam epitaxy technique (MBE technique), a gas source molecular beam epitaxy technique (GSMBE technique) and metal organic CVD technique (MOCVD technique). In the illustrated embodiment, the MBE technique is employed.
In the present embodiment, the x in the n + type In x Ga 1-x As graded-composition layer (x=0→1) 8 is set to increase from 0 to 1 from its bottom to top, whereby the conduction bands of the n + type GaAs layer 7 and n + type InAs layer 9 can be smoothly connected together.
Actually measured results of the carrier concentration for the n + type GaAs layer 7, n + type In x Ga 1-x As intermediate layer or graded-composition layer (x=0→1) 8 as an intermediate layer and n + type InAs layer 9 in the HBT are shown in FIG. 2(b). As will be observed from the drawing, a dip in the carrier concentration of the n + type In x Ga 1-x As intermediate layer is remarkably shallow as compared with that in the prior art.
An emitter contact resistance of the HBT thus obtained was 7×10 -8 Ωcm 2 , which is very small compared with 5×10 -6 Ωcm 2 in the prior art HBT.
In this way, in accordance with the HBT of the present invention, since the emitter resistance can be made very low, its transconductance Gm can be improved over the prior art HBT and therefore the HBT of the present invention can be operated in a high current density zone.
With respect to a cut-off frequency f T as one of the performance criteria of a transistor, the present invention has a cut-off frequency f T of 90 GHz that is remarkably improved over 70 GHz of the prior art.
Given below in Table 1 are measurement results of impurity concentration and corresponding contact specific resistance of the HBT having the same structure as above but when only the impurity concentration of the n + type In x Ga 1-x As intermediate layer 8 is varied.
TABLE 1______________________________________n type impurity concentrationof In.sub.x Ga.sub.1-x As intermediate Contact specificlayer resistances obtained______________________________________5 × 10.sup.18 cm.sup.-3 About 8 × 10.sup.-6 Ωcm.sup.21.5 × 10.sup.19 cm.sup.-3 About 5 × 10.sup.-6 Ωcm.sup.23 × 10.sup.19 cm.sup.-3 About 7 × 10.sup.-8 Ωcm.sup.25 × 10.sup.19 cm.sup.-3 About 5 × 10.sup.-8 Ωcm.sup.2______________________________________
In this case, the upper limit of the obtained in type carrier concentrations is about 2×10 19 cm -3 but as will be seen from the above Table 1, when the impurity concentration of the n + type In x Ga 1-x As intermediate layer 8 is set to be above 3×10 19 cm -3 , a very low contact resistance can be obtained.
EMBODIMENT 2
Explanation will next be made as to an HBT of a second embodiment of the present invention, which has the same structure as the HBT of the embodiment 1 of FIG. 1 and wherein the impurity concentration of the n + type In x Ga 1-x As graded-composition layer 8 is varied therein.
More in detail, in the HBT of the embodiment 2, the n type impurity concentration of the n + type In x Ga 1-x As graded-composition layer 8 is set to gradually decrease from its side of the n + type GaAs layer 7 to the side of the n + type InAs layer 9, as shown in FIG. 3(a). In other words, the HBT of the present embodiment 2 is arranged so that the n type impurity concentration of the n + type In x Ga 1-x As graded-composition layer 8 is gradually decreased from its n + type GaAs layer 7 side to its n + type InAs layer 9 side as shown in FIG. 3(a). That is, the n type impurity concentration d1 of the area of the n + type In x Ga 1-x As graded-composition layer 8 contacted with the GaAs layer 7 is set higher than the n type impurity concentration d2 of that area of the layer 8 contacted with the n + type InAs layer 9. In the present embodiment, the n type impurity concentration d2 of the layer 8 contacted with the InAs contact layer 9 was set at 3.5×10 19 cm -3 while the n type impurity concentration d1 of the area contacted with the GaAs layer 7 is set at 4.0×10 19 cm -3 .
FIG. 3(b) shows measured results of the carrier concentrations for the n + type GaAs layer 7, n + type In x Ga 1-x As intermediate or graded-composition layer (x=0→1) 8 and n + type InAs layer 9 of the HBT. It will be appreciated from the drawing that any appreciable dip in the carrier concentration is not present within the n + type In x Ga 1-x As intermediate layer 8 and the carrier concentration D2 of that area of the n + type In x Ga 1-x As graded-composition layer 8 which is contacted with the InAs contact layer 9 is higher than the carrier concentration D1 of that area of the layer 8 contacted with the GaAs layer.
The emitter contact resistance of the thus obtained HBT was 5×10 -8 Ωcm 2 , which was smaller than the emitter contact resistance of the HBT of the embodiment 1 and that was much smaller than 5×10 -6 Ωcm 2 in the prior art HBT.
In this way, in the case of the HBT of the embodiment 2, since the emitter resistance can be made very small, the transconductance Gm can be further improved and the HBT can be operated in a higher current density zone.
With regard to the cut-off frequency f T as one of the performance indexes of a transistor, the HBT has a cut-off frequency f T of 100 GHz that is much improved over that of the HBT of the embodiment 1.
Given below in Table 2 are measurement results of impurity concentration and corresponding contact specific resistance of the HBT having the same structure as above but when only the impurity concentration of the n + type In x Ga 1-x As intermediate layer 8 is varied.
TABLE 2______________________________________n type impurity concentrationof In.sub.x Ga.sub.1-x As intermediate Contact specificlayer resistances obtained______________________________________d1: 7 × 10.sup.18 cm.sup.-3 About 7 × 10.sup.-6 Ωcm.sup.2d2: 5 × 10.sup.18 cm.sup.-3d1: 2 × 10.sup.19 cm.sup.-3 About 5 × 10.sup.-6 Ωcm.sup.2d2: 1 × 10.sup.19 cm.sup.-3d1: 5 × 10.sup.19 cm.sup.-3 About 7 × 10.sup.-8 Ωcm.sup.2d2: 3 × 10.sup.19 cm.sup.-3d1: 7 × 10.sup.19 cm.sup.-3 About 3 × 10.sup.-8 Ωcm.sup.2d2: 5 × 10.sup.19 cm.sup.-3______________________________________
In this case, the upper limit of the obtained n type carrier concentrations is about 2×10 19 cm -3 but as will be seen from the above Table 2, when the impurity concentration of the n + type In x Ga 1-x As intermediate layer 8 is set to be above 3×10 19 cm -3 , a very low contact resistance can be obtained.
EMBODIMENT 3
In the HBT of the foregoing embodiment 2, the impurity concentration of the n + type In x Ga 1-x As graded-composition layer 8 has been set to be gradually decreased from its GaAs layer 7 side to its InAs contact layer 9 side. In the present embodiment 3, as shown in FIG. 4(a), the n type impurity concentration of the n + type In x Ga 1-x As graded-composition layer 8 is set to have a high level in an area within the layer 8 located apart from that area of the layer 8 contacted with the InAs contact layer 9 by a short distance, and to be gradually decreased from the high-level area to that area of the layer 8 contacted with the GaAs layer 7. FIG. 4(b) shows measured results of the carrier concentrations for the n + type GaAs layer 7, n + type In x Ga 1-x As intermediate or graded-composition layer (x=0→1) 8 and n + type InAs layer 9 of the HBT. It will be observed from the drawing that any appreciable dip in the carrier concentration is not present within the n + type In x Ga 1-x As intermediate layer 8 and the carrier concentration D2 of that area of the n + type In x Ga 1-x As graded-composition layer 8 which is contacted with the InAs contact layer 9 is higher than the carrier concentration D1 of that area of the layer 8 contacted with the GaAs layer. And the emitter contact resistance of the thus obtained HBT was 4×10 -8 Ωcm 2 that was much smaller than the emitter contact resistances of the HBTs of the foregoing embodiments.
The impurity concentration and thickness of the respective semiconductor layers in the HBT are not limited to the particular values used in the foregoing embodiments and may be modified as necessary.
In addition, the present invention may be modified in various ways within the sprit and scope of the attached claims. | A compound semiconductor device wherein a contact to an n type Al x Ga 1-x As layer comprises an In x Ga 1-x As graded-composition layer, an In x Ga 1-x As contact layer having a constant composition and a metal electrode layer, the In x Ga 1-x As graded-composition layer is doped with an n type impurity which concentration is higher than a concentration of an impurity activated as n type, whereby, even when a thickness of the In x Ga 1-x As graded-composition layer is made sufficiently small, a reduction in the carrier concentration of the thin graded-composition layer causes no increase of its resistance and a low-resistance contact is realized. | 7 |
[0001] The present invention relates to photon-to-plasmon couplers for converting photons to plasmons or vice versa.
BACKGROUND OF THE INVENTION
[0002] During the last decade the field of quantum plasmonics has developed into a fast growing research area [1]. For quantum optics experiments on a chip and for the miniaturization of optical applications, plasmons promise unique opportunities since they can beat the diffraction limit of light, reaching extremely high electromagnetic energy densities and low mode volumes [2]. Thus, plasmonic structures offer the tools necessary to achieve a higher level of control to light-matter interactions on a nanometer scale.
[0003] A key step in order to make use of these features is an efficient and controlled in- and out-coupling of plasmons to and from plasmonic structures [3]. For example, in proposed single-photon transistors [4] efficient photon-to-plasmon waveguide coupling is crucial. Furthermore, on-chip detection of plasmons is challenging [5] so that scattering of plasmons into photons and their subsequent detection with standard optical technology seems more feasible at present. Therefore, a number of photon-to-plasmon coupler schemes have been numerically investigated in two dimensions (2D) [6-8] and three dimensions (3D) [9-16] some of which have been fabricated in recent years [9-11].
[0004] Nevertheless, the above coupler schemes exhibit certain shortcomings in particular with respect to quantum plasmonics, so that novel designs are required. Specifically, these designs should allow for easy and reliable fabrication, e.g. via standard electron beam techniques.
OBJECTIVE OF THE PRESENT INVENTION
[0005] An objective of the present invention is to present a photon-to-plasmon coupler that is easy to fabricate and provides a good coupling efficiency between photonic and plasmonic waveguides.
BRIEF SUMMARY OF THE INVENTION
[0006] An embodiment of the invention is directed to a photon-to-plasmon coupler for converting photons to plasmons or vice versa, said photon-to-plasmon coupler comprising
a photonic waveguide for guiding photons, a plasmonic waveguide for guiding plasmons, and two plasmonic strip waveguides, each of said two plasmonic strip waveguides being connected to said plasmonic waveguide and embracing an end section of the photonic waveguide such that each of said plasmonic strip waveguides is optically coupled to the end section of the photonic waveguide.
[0011] This embodiment of the present invention exhibits a very high coupling efficiency. The coupling results from an evanescent field between the plasmonic strip waveguides and the photonic waveguide. The coupling efficiency has been confirmed by 3D-simulation of the results which are described further below with reference to the figures.
[0012] Preferably, the two plasmonic strip waveguides form a Y-shaped plasmonic strip waveguide structure that converges towards the plasmonic waveguide and embraces the end section of the photonic waveguide.
[0013] Two stripe-like gaps may be formed between the Y-shaped plasmonic strip waveguide structure and the end section of the photonic waveguide. Via the width of the gap, the coupling behaviour may be optimized. The ratio between the width of the gap and the width of the plasmonic strip waveguides is preferably between 0.01 and 2.
[0014] The width of the gap between one of the plasmonic strip waveguides and the end section of the photonic waveguide preferably equals the width of the gap between the other one of the plasmonic strip waveguides and the end section of the photonic waveguide.
[0015] The width of the gap between the first section of each of the plasmonic strip waveguides and the end section of the photonic waveguide may be at least partially constant along the propagation direction of the photons and plasmons.
[0016] Preferably, the waveguide width of the plasmonic strip waveguides is at least partially or entirely constant along the propagation direction of the photons and plasmons. The plasmonic strip waveguides are preferably plasmonically decoupled from one another by the end section of the photonic waveguide.
[0017] Each of the plasmonic strip waveguides preferably comprises a first section being coupled to the photonic waveguide, and a second section that is less coupled to the photonic waveguide than the first section or entirely decoupled from the photonic waveguide.
[0018] The ratio between the length of the second section of each of the plasmonic strip waveguides and the width of the photonic waveguide is preferably between 1 and 4.
[0019] The photonic waveguide may comprise a middle section adjacent to the end section. The waveguide width of the middle section of the photonic waveguide may be larger than the width of each of the plasmonic strip waveguides. Alternatively, the waveguide width of the middle section of the photonic waveguide and the width of each plasmonic strip waveguide may be equal.
[0020] The end section of the photonic waveguide is preferably tapered, e.g. adiabatically tapered. The term “adiabatically tapered” refers to a taper that changes its waveguide width so smoothly that the additional losses caused by the taper are negligible.
[0021] The plasmonic waveguide may be a strip waveguide and may form a third plasmonic strip waveguide of the photon-to-plasmon coupler. Alternatively, the plasmonic waveguide may be a slot waveguide that is connected to each of the plasmonic strip waveguides.
[0022] The width of each of the plasmonic strip waveguides is preferably either smaller than the width of the plasmonic waveguide or as large as the width of the plasmonic waveguide.
[0023] A further embodiment of the present invention relates to a photon-to-plasmon coupler for converting photons to plasmons or vice versa, said photon-to-plasmon coupler comprising
a photonic waveguide for guiding photons, a plasmonic waveguide for guiding plasmons, and two plasmonic strip waveguides, that converge towards the plasmonic waveguide and form a Y-shaped plasmonic strip waveguide structure, said Y-shaped plasmonic strip waveguide structure being optically coupled to an end section of the photonic waveguide.
[0028] As discussed above, a Y-shaped plasmonic strip waveguide structure supports an evanescent coupling between the two plasmonic strip waveguides and the photonic waveguide.
[0029] A further embodiment of the present invention relates to a photon-to-plasmon coupler for converting photons to plasmons or vice versa, said photon-to-plasmon coupler comprising
a photonic waveguide for guiding photons, a plasmonic waveguide for guiding plasmons, and two plasmonic strip waveguides, each of said two plasmonic strip waveguides being coupled to an end section of the photonic waveguide but separated from the end section of the photonic waveguide by a gap.
[0034] As discussed above, the width of the gap provides a further parameter for optimizing the evanescent coupling between the two plasmonic strip waveguides and the photonic waveguide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order that the manner in which the above-recited and other advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended figures. Understanding that these figures depict only typical embodiments of the invention and are therefore not to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail by the use of the accompanying drawings:
[0036] FIG. 1 shows a first exemplary embodiment of a photon-to-plasmon coupler according to the present invention.
[0037] FIG. 2 shows the energy flux Φ along the surface plasmon waveguide after the coupling process of the coupler shown in FIG. 1 . The flux is normalized to the incoming energy flux Φ0. The fast decay at the beginning corresponds to scattered light whereas the slow decay fits to the predicted waveguide damping and thus corresponds to the guided plasmon mode. The intensity value at a propagation length of zero gives the coupling efficiency η.
[0038] FIG. 3 shows—with respect to the coupler shown in FIG. 1 —the field distribution (intensity) of the momentum-matched guided (a) dielectric and (b) plasmonic mode.
[0039] FIG. 4 shows—with respect to the coupler shown in FIG. 1 —a top view on electrical field distribution (component parallel to SiO2 surface) at the interface between air and the SiO2-substrate with the mesh of the coupler geometry (only upper half).
[0040] FIG. 5 shows—with respect to the coupler shown in FIG. 1 —the dependence of the coupling efficiency on the taper-length L 1 starting from the optimized structure revealing an oscillatory behavior. The solid line is fit of the data with the analytic model A*exp(−Bx)*cos(Cx)+D.
[0041] FIG. 6 shows—with respect to the coupler shown in FIG. 1 —the wavelength dependence of the coupling efficiency η of the optimized structure. The solid line is a guide for the eye.
[0042] FIGS. 7-15 show an exemplary embodiment of process steps for fabricating the photon-to-plasmon couplers of FIGS. 1 and 16 .
[0043] FIG. 16 shows a second exemplary embodiment of a photon-to-plasmon coupler according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The preferred embodiments of the present invention will be best understood by reference to the drawings, wherein identical or comparable parts are designated by the same reference signs throughout.
[0045] It will be readily understood that the present invention, as generally described herein, could vary in a wide range. Thus, the following more detailed description of the exemplary embodiments of the present invention, is not intended to limit the scope of the invention, as claimed, but is merely representative of presently preferred embodiments of the invention.
[0046] FIG. 1 shows a first exemplary embodiment of a photon-to-plasmon coupler 10 according to the present invention. The photon-to-plasmon coupler 10 comprises a photonic waveguide 20 for guiding photons. The photonic waveguide 20 is preferably a dielectric waveguide.
[0047] The photon-to-plasmon coupler 10 further comprises a plasmonic waveguide 30 for guiding plasmons and two plasmonic strip waveguides 40 and 50 . The plasmonic waveguide 30 and the two plasmonic strip waveguides 40 and 50 are preferably made of metal.
[0048] The two plasmonic strip waveguides 40 and 50 are connected to the plasmonic waveguide 30 and embrace an end section 21 of the photonic waveguide 20 such that each of the plasmonic strip waveguides 40 and 50 is optically coupled to the end section 21 of the photonic waveguide 20 .
[0049] FIG. 1 shows that the two plasmonic strip waveguides 40 and 50 form a Y-shaped plasmonic strip waveguide structure 51 that converges towards the plasmonic waveguide 30 and embraces the end section 21 of the photonic waveguide 20 . The two plasmonic strip waveguides 40 and 50 are also referred to as V-shaped metal arms hereinafter.
[0050] Two stripe-like gaps 60 and 70 are formed between the Y-shaped plasmonic strip waveguide structure 51 and the end section 21 of the photonic waveguide 20 . The width D of the gaps 60 and 70 strongly influences the coupling behaviour of the photon-to-plasmon coupler 10 .
[0051] The ratio between the width D of the gaps 60 and 70 and the width Wp of the plasmonic strip waveguides 40 and 50 is preferably between 0.01 and 2. The width D of the gap 60 between the plasmonic strip waveguide 40 and the end section 21 of the photonic waveguide 20 preferably equals the width D of the gap 70 between the plasmonic strip waveguide 50 and the end section 21 of the photonic waveguide 20 .
[0052] The plasmonic strip waveguides 40 and 50 preferably comprise a first section 42 and 52 that is coupled to the photonic waveguide 20 , and a second section 43 and 53 that is less coupled to the photonic waveguide 20 than the first section 42 and 52 or entirely decoupled from the photonic waveguide 20 .
[0053] The width D of the gaps 60 and 70 between the first section 42 and 52 of both plasmonic strip waveguides 40 and 50 and the end section 21 of the photonic waveguide 20 is preferably at least partially constant along the propagation direction of the photons and plasmons. In addition, the waveguide width Wp of the plasmonic strip waveguides 40 and 50 is at least partially or entirely constant along the propagation direction of the photons and plasmons.
[0054] The ratio between the length L 2 of the second section 43 and 53 of the plasmonic strip waveguides 40 and 50 and the width Wd of the photonic waveguide 20 in a middle section 22 is preferably between 1 and 4.
[0055] The end section 21 of the photonic waveguide 20 is preferably adiabatically tapered.
[0056] In the embodiment shown in FIG. 1 , the plasmonic waveguide 30 is a strip waveguide and forms a third plasmonic strip waveguide of the photon-to-plasmon coupler 10 .
[0057] Alternatively, the plasmonic waveguide 30 may be a slot waveguide that is connected to each of the plasmonic strip waveguides. Such an embodiment is shown in FIG. 16 .
[0058] Preferred materials for the plasmonic waveguide 30 and the two plasmonic strip waveguides 40 and 50 are silver, gold, copper, and aluminium. The photonic waveguide 20 is preferably a dielectric waveguide which may consist of or comprise silicon, silicon dioxide, silicon nitride, gallium phosphide, and/or acrylic glass.
[0059] Typical sizes of the photonic waveguide 20 are heights from 50 nm to 5 μm and widths of 100 nm to 10 μm. The typical sizes of the plasmonic waveguides 30 , 40 and 50 are widths of 50 nm to 10 μm and heights of 10 nm to 300 nm.
[0060] The photon-to-plasmon coupler 10 may be optimized with simulation tools. The explanations hereinafter and the results discussed with regard to specific dimensions of photon-to-plasmon couplers are to be understood as exemplary, only.
[0061] The photon-to-plasmon coupler 10 shown in an exemplary fashion in FIG. 1 may exhibit a strong evanescent field at frequencies corresponding to 780 nm vacuum wavelength which is accessible with single emitters. For characterization and optimization a full 3D simulation of the structure has been performed and the coupling efficiency η has been calculated.
[0062] The rectangular dielectric waveguide 20 of the photon-to-plasmon coupler 10 shown in FIG. 1 is tapered at one end. The increasing evanescent part of the waveguide's electromagnetic field couples over gaps 60 and 70 to the V-shaped metal arms 40 , 50 which merge with the plasmonic waveguide near the taper tip into a straight rectangular metal waveguide 30 for surface plasmons.
[0063] The coupler-structure is completely defined by both waveguide's cross sections (which are fixed after matching their effective refractive indices) and four free parameters: i) the distance De of the metal arms from the dielectric waveguide at their ends, i) the width D of the gaps 60 and 70 between dielectric and metal in the taper region, iii) the width Wp of the metal arms, and iv) the length L 1 of the tapered region (see FIG. 1 ).
[0064] The materials considered here are silicon-nitride (Si3N4) for the dielectric and gold (Au) for the plasmonic waveguides on a silica-substrate (SiO2). The structure has been optimized for a wavelength of 780 nm with the relative permeabilities ∈′+i∈″ of 3.99 (Si3N4), 2.37 (SiO2) and −22.46+i1.39 (Au). These values respectively correspond to refractive indices n′+in″ of 1.9974, 1.5388 and 0.1754+i4.9123.
[0065] Since coupling of single emitters to the structures on the chip for example by nano-manipulation techniques is desired, gold has been chosen over silver because it does not oxidize and thus can be used without protective capping layers.
[0066] Silicon nitride on SiO2 is chosen for convenience, as it is commercially available grown on silicon wavers, nicely processable by lithography and widely used in waveguiding. Compared to silicon, Si3N4 has a wide bandgap and is used for integrated optical structures in the visible spectral range. This general coupler-scheme fulfils heavy demands for easy fabrication since it only requires standard e-beam lithography methods.
[0067] For the simulations a commercial FEM Maxwell's equations-solver (JCMwave) has been used which allows for full 3D computations and supports non-uniform and adaptive meshing. FEM generates relatively fast and accurate simulation results for setups involving metals and complex 3D geometries, also convergence checks are straight-forward. In order to optimize the structure towards a high coupling efficiency the Taguchi-method has been used which is well known in the field of design of experiments (DoE). Taguchi's statistical method strongly reduces the number of computational runs. In this case with 4 parameters (De, D, Wp, L 1 ) where each is varied over a reasonable range in 3 steps (levels), the number of required runs can be reduced to 9 (instead of 3 4 =81 generally needed to check all possible combinations of 4 parameters and 3 levels). The combination of FEM with the Taguchi-method makes the approach very time-efficient.
[0068] First, the performance of the uncoupled photonic and plasmonic waveguides is investigated. With a propagating mode solver it is searched for thickness and height of the rectangular waveguides where single mode operation is ensured. The importance of these first calculations is threefold: i) a field distribution for the dielectric waveguide is computed which can be used as a source for the full coupler computations, ii) the effective refractive indices n eff (and thus their propagation constants β=2π*Re(n eff )/λ) of the dielectric and those of the plasmonic modes can be matched, and iii) the damping of the surface plasmons in the metal waveguide can be derived. With the source thus generated, the simulations of the coupler can be performed.
[0069] A very important step in coupler design is a precise and reliable evaluation of the coupling efficiency η. The evaluation method uses the fact that only the guided field, i.e. the plasmon will be confined to the metallic waveguide over longer distances in contrast to scattered fields. Therefore, a total of 5 μm of plasmon waveguide is retained in the computational domain and the Poynting vector fields in planes perpendicular to the propagation direction in equal steps along the waveguide are exported. By summing up over all points of the exported fields the flux Φ can be obtained through these surfaces.
[0070] FIG. 2 shows the results for the optimized structure where a fast decay followed by a slower exponential decay can be clearly observed. The latter is fit with a mono-exponential model f(z)=A0 exp(−αz) where α is the attenuation constant of the plasmon mode derived from the propagating mode solver (α=4π Im(n eff )/λ). The amplitude A0 which is the only open parameter of the fit gives us the coupling efficiency η directly after the coupler, i.e. where the metal stripe waveguide begins (after normalization to the source field's energy-flux Φ0). It is noted that the method is independent of assumptions regarding power-orthogonality. This is in contrast to several other methods that have been utilized in prior art. It is also emphasized that the method used here does not simply place a “monitor” at the end of the coupler which would easily lead to an overestimated coupling efficiency η.
[0071] For both waveguides two guided modes are found, a purely TE and TM mode for the dielectric waveguide, whereas there are two TEM modes for the metal waveguide. The field distributions of the momentum-matched modes for both waveguides are depicted in FIG. 3 .
[0072] An n eff-diel of 1.6886 for the TE mode of the dielectric waveguide with a height of 300 nm and a width of 510 nm and an n eff-metal of 1.6871+i0.0166 for the metallic waveguide with a height of 50 nm and a width of 400 nm is found, respectively. The imaginary part of n eff-metal corresponds to a decay constant of α=3.74 μm. The TE mode has been chosen due to geometric reasons: since its evanescent field is pronounced at the sides of the waveguide it will couple over the gap in the tapered region and its polarization parallel to the silica-substrate SiO2 surface is well suited to polarize the metal arms and thus excite plasmons.
[0073] Now the coupler problem is computed. After the Taguchi-optimization the best coupling efficiency of η=47% is found for the parameters De=100 nm, D=24 nm, Wp=120 nm and L 1 =1030 nm. The mesh of the coupler problem and the field distribution are shown in FIG. 4 . It is pointed out that by capping the structure with a higher index dielectric than air and using silver instead of gold, higher coupling efficiencies η's above 60% can easily be reached.
[0074] A drawback of the Taguchi-method is the missing insight into the importance of the individual parameters on the result. In order to analyze effects caused by imperfections in fabrication four parameter scans have been performed. Starting from the optimized structure the parameter may be varied while keeping the others fixed. Whereas the three parameters De, D and Wp show only moderate influence on the coupling efficiency η the scan of the taper length L 1 reveals a clear oscillatory behavior ( FIG. 5 ). This reflects the working principle of the coupler design: the evanescent part of the dielectric mode excites surface plasmons in the V-shaped metal arms, the electromagnetic energy is then coupled back and forth between the inner and outer edge of the arms while propagating towards the taper-tip. The coupling efficiency η is at its maximum when the taper length L 1 is such that most of the electromagnetic energy has coupled to the outer side and fits to the field distribution of the guided plasmon mode. At the same time the taper length L 1 has to be kept as short as possible because of dissipative attenuation in the metal arms 40 and 50 .
[0075] FIG. 6 shows the spectral bandwidth of the coupler by scanning over a variety of input frequencies (dielectric constants taken from Ref. 25). From this a broad bandwidth of approximately 220 nm can be extracted.
[0076] In conclusion, an easy-to-fabricate, versatile photon-to-plasmon coupler for on-chip quantum plasmonics has been presented. In contrast to prior art, the focus is on shorter wavelength in the visible spectral range. By using FEM combined with the Taguchi-method a very time-efficient optimization and computation approach executable on conventional PCs has been presented. To avoid overestimated coupling efficiency a simple but reliable method based on the decay of coupled plasmons has been introduced.
[0077] FIGS. 7-15 show exemplary method steps for fabricating the couplers 10 that are shown in FIGS. 1 and 16 . The method steps start from a layer structure comprising a silicon wafer 100 , a SiO2-layer 110 , and a SiN-layer 120 as shown in FIG. 7 .
[0078] FIGS. 8 , 9 and 10 show the fabrication of the photonic strip waveguide 20 . The SiN-layer 120 is structured by a lithography step that includes a photo resist layer 130 and an etch step. The photonic strip waveguide 20 is formed by a remaining strip in the SiN-layer 120 .
[0079] Thereafter, the two plasmonic strip waveguides 40 and 50 are fabricated. This is shown in FIGS. 12-15 . The photonic strip waveguide 20 is covered by a second photoresist layer 140 . Then, a metal layer 150 is deposited thereon. By removing the buried photoresist layer 140 the photonic strip waveguides 40 and 50 are completed.
REFERENCE NUMERALS
[0000]
10 photon-to-plasmon coupler
20 photonic waveguide
21 end section
22 middle section
30 plasmonic waveguide
40 plasmonic strip waveguide
42 first section
43 second section
50 plasmonic strip waveguide
51 Y-shaped plasmonic strip waveguide structure
52 first section
53 second section
60 stripe-like gap
70 stripe-like gap
100 silicon wafer
110 Si02-layer
120 SiN-layer
130 photo resist layer
140 photo resist layer
150 metal layer
D width of the gaps
De distance
L 1 length
L 2 length
Wd width of the photonic waveguide
Wp width of plasmonic strip waveguide
LITERATURE
[0000]
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[39] G. Kewes et al. Appl. Phys. Lett., 102, 051104, (2013) | An embodiment of the present invention relates to a photon-to-plasmon coupler for converting photons to plasmons or vice versa, said photon-to-plasmon coupler comprising
a photonic waveguide for guiding photons, a plasmonic waveguide for guiding plasmons, and two plasmonic strip waveguides, each of said two plasmonic strip waveguides being connected to said plasmonic waveguide and embracing an end section of the photonic waveguide such that each of said plasmonic strip waveguides is optically coupled to the end section of the photonic waveguide. | 6 |
This invention relates to an improved article carrying member detachably secured to a conveyor chain and more particularly relates to a construction of such carrying member alone and in combination with a conveyor chain enabling breakaway of a carrying member without damage to the chain.
BACKGROUND OF THE INVENTION
Conveyor chains with one or more article carrying members are well known in the prior art. For examples: Lynch U.S. Pat. No. 1,707,088 shows solid cylindrical rods extending to one side of successive roller chain links with each rod having a reduced shank in the form of a pintle that acts as a link pin in the chain; Talbott U.S. Pat. 4,129,206 shows a similar link pin and rod with a scored sleeve, for receiving an empty can, extending outward of a hub rotatably mounted on the rod; Tracy U.S. Pat. No. 4,501,351 shows similar rods extending to one side of occasional special roller chain links wherein each rod pintle is plugged into a hollow link pin and the rod is coupled to an adjacent extended regular link pin by a supplemental link plate that is fastened substantially flush against an interconnected regular outer pin link plate by a cotter pin through the regular link pin; and Michalik U.S. Pat. No. 4,388,990 shows a modified roller chain wherein each link pin extends uniformly beyond the outer pin link plate to one side of the chain and solid cylindrical extension rods are connected to and aligned with occasional pins by means of split sleeves or bushings which will open to release the extension rods should an obstruction occur in the conveyor path. There is also a known commercially available variation of the Tracy patent structure (produced by a division of the patent assignee, Incom International Inc.) wherein the pintle is eliminated and a hollow rod is press fitted to the end of one extended regular link pin and coupled to an adjacent extended link pin by a cotter pin and a supplemental link plate that is mounted flush with the rod end.
A disadvantage of the aforedescribed prior art, with the exception of the Michalik patent, is that the rods, which are spaced in accordance with the particular conveyor installation to carry items suspended to one side of a single chain conveyor, are made essentially integral with the chain and risk damage to the chain, such as a chain break or detachment from the chain drive, should something obstruct movement of the rods or articles carried thereby. Since these chains are usually utilized to transport articles between and through processing stations, such obstructions do occur; and additionally significant routine forces are imparted to the rods at the processing stations. In the Talbott patent structure the sleeve is weakened to break free outwardly of the supporting rod but the chain is not fully protected thereby. While the structure of the Michalik patent overcomes, to a degree, the risk of chain damage, it involves a significant risk that the split sleeve will open to release the carrying rod when subjected to routine processing forces or that it will gradually allow the rod to slip away during repeated cycles through processing operations. The latter risk is further increased if there is even a slight difference between the cross sections of the link pin and an extension rod aligned therewith because one will tend to hold open the split sleeve respecting the other. The present invention overcomes the deficiencies of the structure described by Michalik.
SUMMARY OF THE INVENTION
Accordingly it is a principal object of the present invention to provide an improved article carrying member for a conveyor chain that will readily detach without damage to the chain if subjected to unusual forces yet will not detach due to repeated routine forces.
Another object of the present invention is to provide an article carrying member and means for detachably connecting it to a conveyor chain link pin which means will compensate for differences in the cross section of the connected parts.
A further object of the present invention is to provide conveyor chain with an article carrying member connected to a chain link pin by means which will compensate for differences in the cross sections of the connected parts.
Briefly stated the invention comprises a carrying member for a roller chain with at least some link pins that extend a short distance beyond the outer pin link plates to one side of the chain, wherein the carrying member has at least one extension rod aligned with a link pin and connected thereto by a fracturable split sleeve which sleeve is telescoped over both the rod and pin with a compression member applied to close the split sleeve on both parts.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages will become apparent upon reading the following detailed description of the present invention in conjunction with the accompanying drawing wherein:
FIG. 1 is a plan view of a preferred embodiment of the invention with an article carrying member shown mounted to a link pin projecting to one side of a roller chain; and
FIG. 2 is a sectional view taken at line 2--2 in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 it will be seen that an article carrying member generally 10 extends to one side of an essentially standard form of conveyor chain generally 12. The conveyor chain 12 comprises a plurality of sets of paired rollers 20, 22 rotatably supported on bushings or the like (not shown) between roller link plates 24, 26 with successive adjacent roller sets interconnected by outer pin link plates 30, 32 and link pins 40, 42. As is well understood the link pins 40, 42 extend coaxially with rollers and holes (not shown) in successive pairs of roller link plates 24, 26 and 24a, 26a and through holes (not shown) in the outer pin link plates 30, 32. In the preferred conveyor configuration each link pin has an extended end 44 that projects a short distance beyond the respective pin link plate 32, which distance is sufficient to receive the carrying member 10 as hereafter described. The projection distance will, of course, vary with the size of the chain, but a distance of about one four tenths (0.4) inch is usually adequate for chain sized to have a pitch of about three quarters (0.75) of an inch.
The preferred carrying member 10 comprises a cylindrical extension rod 50, which may be either solid or hollow, having an outer dimension and cross section substantially the same as the projecting end 44 of a link pin 40 to which it is to be aligned and mounted. A split sleeve or bushing 52 having a longitudinal opening 54 and a normal internal dimension slightly less than the outer diameter of the link pin 40 is pressed onto the projecting end 44 thereof and telescoped thereover until a sleeve end 56 abuts the pin link plate 32. The split sleeve 52 must be of a length greater than the distance the link pin end 44 extends from the pin link plate 32 and sufficient to grip and retain an end of the extension rod 50. Preferably the sleeve 52 length is more than twice the extension of pin end 44 and optimally is about three times that distance so as to receive a relatively greater length of extension rod 50. As seen in FIG. 1, the rod 50 is pressed into the sleeve 52 so as to abut the end 44 of link pin 40.
The longitudinal opening 54 in sleeve 52 may be randomly oriented, that is there is no preferred position with respect to the direction of conveyor travel as it is intended that the split sleeve 52 not act to open and thereby separate from the link pin 40 when an excessive force is applied to the extension rod 50. Instead, according to the present invention, the split sleeve 52 includes a compression means that functions to urge the longitudinal opening 54 to close toward both ends and thereby compress upon both a link pin end 44 and an end of extension rod 50 even where either part may differ slightly in diameter or be slightly out of round. The compression means may take the form of an encircling washer 60 that is pressed onto the outer surface of split sleeve 52 and positioned at about the juncture of pin end 44 and rod 50. Preferably the washer 60 is positioned with one face 62 at the plane of the link pin end 44 and with the body of the washer encircling the end of rod 50.
The split sleeve 52 is a low cost coupling device and the longitudinal opening 54 therein functions mainly to permit telescoping onto both the link pin 40 and extension rod 50. The sleeve is designed to fracture so as to permit detachment of the extension rod from the link pin end 44. To accomplish this the sleeve may be fabricated from a relatively brittle material, such as carburized steel, and/or it may have an encircling score 64 on the outer surface thereof. Where a weakening score 64 is utilized, it is preferably located adjacent the face 62 of washer 60 so that any detachment fracture will occur at the plane of juncture between pin end 44 and rod 50. Should such detachment occur a carrying member 10 may be readily replaced after first extracting the part of a split sleeve 52 that may remain on a link pin end 44.
Obviously the conveyor chain generally 12 may have any appropriate member and spacing of the aforedescribed carrying member 10, particularly if all link pins 40, 42 throughout the conveyor have uniformly extended ends 44. However, it is possible to employ a single extended pin in each pair sharing pin link plates 30, 32 or even to employ extended pins at only those points appropriately spaced in a given application. Moreover, the extension rod 50 may be modified to include a variety of shapes, such as a hook or funnel, or appendages, such as clamps or grommets, outward of the rod end that telescopes within the split sleeve 52.
Other alterations and modifications may be made without departing from the spirit and scope of the present invention which is defined in the following claims: | A conveyor chain and an article carrying member extending from a chain link pin wherein the carrying member comprises a rod aligned and abutted to a link pin and secured thereto by a fracturable split sleeve and a compression washer pressed on the outside of the sleeve. | 1 |
The invention concerns a cutting tool comprising a main body and a multi-layer coating applied thereto.
STATE OF THE ART
Cutting tools include a main body which is made for example from hard metal, cermet, steel or high speed steel and a single-layer or multi-layer hard material coating applied to the main body to increase the service lives or also to improve the cutting properties. CVD processes (chemical vapour deposition) and/or PVD processes (physical vapour deposition) are used to apply the hard material coating.
WO 96/23911 describes a cutting tool comprising a multi-layer wear resistant coating comprising a plurality of individual layers, wherein an individual layer comprising a hard metallic material is applied directly to the main body and further individual layers are arranged thereover so that the individual layers form a periodically repeating composite comprising three different respective individual layers, which each include two different metallic hard material layers and a covalent hard material layer. In an embodiment described as being preferred the three-layer composite comprises two individual layers of titanium nitride and titanium carbide and an individual layer comprising the covalent hard material boron carbide. It is described therein that the wear resistant coating is to include at least three covalent hard material layer portions and thus comprises at least nine individual layers. Preferably the first individual layer disposed on the main body is a layer of titanium nitride or titanium carbide as they are said to adhere well to the main body of steel or hard metal. Besides the particularly preferred boron carbide, silicon carbide, silicon nitride, boron nitride, Sialon (mixed crystal of silicon and aluminium oxynitride), carbon and others are specified for the individual layers of covalent hard material. It has been found however that the described individual layers comprising the hard metallic materials titanium nitride and titanium carbide do not meet the present day demands in terms of protection from wear. Titanium carbide is admittedly hard but it is too brittle for a wear resistant layer. Titanium nitride is softer and less brittle than titanium carbide. Both titanium carbide and also titanium nitride have inadequate temperature resistance for uses involving high temperature loadings. Heat dissipation into the chips and cuttings when machining metal is also inadequate.
Object
The object is attained by a cutting tool comprising a main body and a multi-layer coating applied thereto, wherein applied to the main body is a first layer A of a hard material selected from titanium aluminium nitride (TiAIN), titanium aluminium silicon nitride (TiAISiN), chromium nitride (CrN), aluminium chromium nitride (AICrN), aluminium chromium silicon nitride (AICrSiN) and zirconium nitride (ZrN), and a second layer B of silicon nitride (Si 3 N 4 ) is applied directly over the first layer A.
DESCRIPTION OF THE INVENTION
The object is attained by a cutting tool comprising a main body and a multi-layer coating applied thereto, wherein applied to the main body is a first layer A of a hard material selected from titanium aluminium nitride (TiAlN), titanium aluminium silicon nitride (TiAlSiN), chromium nitride (CrN), aluminium chromium nitride (AlCrN), aluminium chromium silicon nitride (AlCrSiN) and zirconium nitride (ZrN), and a second layer B of silicon nitride (Si 3 S 4 ) is applied directly over the first layer A.
In comparison with the metallic hard material layers like for example TiC or TiN known from the state of the art, the first nitride layer A has markedly improved temperature resistance and at the same time a high degree of hardness which is comparable to the hardness of TiC but which is not as brittle as same. The second layer of silicon nitride (Si 3 N 4 ) is hard and wear-resistant and in combination with the first nitride layer A very effectively prevents heat transfer through the wear resistant coating into the main body and thus promotes improved heat dissipation into the chips and cuttings in metal machining with the cutting tool. Prevention of the heat transfer is similarly effectively caused by the silicon nitride as by aluminium oxide which is very frequently used as a hard wear resistant layer. In addition the second layer B of silicon nitride (Si 3 N 4 ) has very high resistance to oxidation even at high temperatures.
In a particularly preferred embodiment of the invention the first layer A of hard material is applied directly to the main body. It affords particularly good adhesion between the silicon nitride and the main body, particularly if the first layer A comprises TiAlN.
In a further preferred embodiment of the invention at least one further periodically repeated succession of layers A and B is applied over the second layer B, wherein the layers A in the periodically repeated succession of layers A and B are also selected from titanium aluminium nitride (TiAlN), titanium aluminium silicon nitride (TiAlSiN), chromium nitride (CrN), aluminium chromium nitride (AlCrN), aluminium chromium silicon nitride (AlCrSiN) and zirconium nitride (ZrN), but can be different from the hard material of the first layer A. Preferably the layers A are each titanium aluminium nitride (TiAlN) and the layers B are respectively silicon nitride (Si 3 N 4 ).
In a further preferred embodiment of the invention the silicon nitride (Si 3 N 4 ) of the hard material layer B is amorphous. Amorphous silicon nitride has surprisingly good wear resistant properties and good temperature resistance with at the same time a high level of hardness.
The silicon nitride (Si 3 N 4 ) of the hard material layer B can respectively contain up to 20 atomic %, preferably up to 5 atomic %, of usual or unusual impurities or doping elements. Those usual or unusual impurities or doping elements are preferably selected from oxygen, carbon, boron, gallium and arsenic.
In a quite particularly preferred embodiment of the invention the hard material of the first layer A is titanium aluminium nitride (TiAlN). TiAlN has proven to be particularly advantageous in combination with the second layer B of silicon nitride (Si 3 N 4 ). TiAlN has a cubic face-centered crystal lattice like also TiAlSiN which can be contained in the TiAlN layer in an amount of up to 5% by weight.
In a further embodiment of the invention applied over the layers A and B or the periodically repeated composite of layers A and B is at least one further hard material layer or metallic layer selected from aluminium oxide, aluminium chromium oxide, chromium oxide, zirconium nitride, titanium nitride and aluminium metal, wherein all aforementioned hard materials can be optionally doped with one or more further elements.
In a variant of the invention at least one further hard material layer comprising aluminium oxide is applied over the layers A and B and applied thereover is a further layer of zirconium nitride, titanium nitride or aluminium metal.
The further layers which can be applied over the layers A and B are basically known. Aluminium oxide is for example a very hard and good wear resistant layer, and similarly also aluminium chromium oxide and chromium oxide. In comparison zirconium nitride, titanium nitride and aluminium metal are usually applied for colouring the cutting tool and as indicator layers for use of the cutting tool, in the form of outermost layers.
Desirably the multi-layer coating according to the invention has an overall layer thickness in the region of 2 to 10 μm, preferably 3 to 6 μm. Desirably the first layer A which is preferably applied directly to the main body has a layer thickness in the region of 0.5 to 4 μm, preferably 1 to 3 μm. The layer thicknesses of optionally present further layers A are in comparison desirably in the region of 0.2 to 2 μm, preferably 0.3 to 1 μm. Desirably the layers B have layer thicknesses in the region of 0.2 to 5 μm, preferably 0.3 to 3 μm, particularly preferably in the region of 0.5 to 1 μm. With excessively great layer thicknesses there is generally the risk of spalling because of excessively high mechanical stresses in the layer. With excessively small layer thicknesses there is the danger that the respective individual layer does not perform the function wanted therefrom or does not adequately perform it.
Preferably the layers A and B in the coating according to the invention are layers applied to the main body by means of PVD processes, wherein the layers A are particularly preferably applied by means of arc vapour deposition (arc PVD) and the layers B are particularly preferably applied by means of magnetron sputtering, in particular dual magnetron sputtering or HIPIMS (high power impulse magnetron sputtering).
The main body of the cutting tool according to the invention is preferably produced from hard metal, cermet, steel or high speed steel (HSS).
The novel coating of the present invention affords a broad range of possible options for improving and/or adapting wear resistance, service lives and cutting properties of cutting tools. The wear resistance, stability and cutting properties of a coating on a cutting tool depend on various factors such as for example the material of the main body of the cutting tool, the succession, nature and composition of the layers in the coating, the thickness of the various layers and not least the nature of the cutting operation performed with the cutting tool. Different levels of wear resistance can be afforded for one and the same cutting tool in dependence on the nature of the workpiece to be machined, the respective machining process and the further conditions during the machining operation such as for example the generation of high temperatures or the use of corrosive cooling fluids. In addition a distinction is drawn between various kinds of wear which can influence the period of use of a tool, that is to say its service life, to a greater or lesser extent, depending on the respective machining operation. Therefore further development of and improvement in cutting tools is always to be considered in consideration of which tool properties are to be improved and are to be assessed under comparable conditions in comparison with the state of the art.
Substantial improvements in the cutting tools according to the invention with a main body and a multi-layer coating according to the invention are adhesion of the coating on the main body, which is improved over the state of the art, better high-temperature properties, better hardness values and improved wear resistance.
A further surprising effect which was observed with the coatings according to the invention is a reduction in the thermal conductivity of the overall coating. That surprisingly achieved reduction in thermal conductivity of the coating has a highly positive effect in use of such cutting tools in cutting metals and composite materials. The reduced thermal conductivity leads to improved thermal shock resistance and thus increased comb cracking strength of the material of the main body, in particular hard metal.
It is self-evident that all individual features as are described herein for certain embodiments according to the invention, insofar as this is technically meaningful and possible, can be combined with all other described features of embodiments according to the invention and such combinations are deemed to be disclosed within this description. It is only for reasons of better readability that individual naming of all possible combinations is dispensed with herein.
Further advantages, features and embodiments of the present invention are described by means of the following examples.
EXAMPLES
In a PVD coating installation (Flexicoat; Hauzer Techno Coating) hard metal main bodies were provided with a multi-layer PVD coating. The geometry of the main body was SEHW120408 or ADMT160608-F56 (according to DIN-ISO 1832). Before deposition of the layers the installation was evacuated to 1×10 −5 mbar and the hard metal surface cleaned by etching with argon ions at 170 V bias voltage.
Example 1
Layer A: TiAlN
PVD-process: Arc vapour deposition (Arc-PVD)
Target: Ti/Al (33/67 atomic %),round source (63 mm diameter)
Deposition: Temperature: 500° C.; vaporiser current: 65 amperes; 3.2 Pa N 2 pressure, 50 volts substrate bias voltage
Layer B: Si 3 N 4
PVD process: Dual magnetron sputtering
Target: Rectangular Si source (80 cm×20 cm)
Deposition: Temperature: 500° C.; 6 W/cm 2 ; 200 sccm N 2 ; 0.5 Pa Ar pressure, 90 volts substrate bias voltage
Structure X-ray amorphous
Bonding character: Covalent according to XPS
Layer succession: Main body/2.5 μm TiAlN/0.6 μm Si 3 N 4 .
Comparative Example 1
Deposition of a 3.3 μm thick TiAlN layer with otherwise the deposition parameters of Example 1, but without deposition of a further silicon nitride layer B.
In a milling test on a workpiece comprising 42CrMo4-steel (strength: 950 MPa), the cutting tools of Example 1 and comparative Example 1 were compared. Downcut milling was effected without cooling lubricant at a cutting speed v c =235 m/min and with a tooth advance f 2 =0.2 mm. Wear was measured on the relief surface as mean wear mark width VB mm (at the main cutting edge) after a milling travel of 4800 mm.
The following wear mark widths VB were found:
Wear mark width VB
Example 1:
0.06 mm
Comparative Example 1:
0.10 mm
Example 2
The layer of TiAlN and the layer B of Si 3 N 4 was deposited with the same PVD processes and with the same parameters as in Example 1.
Layer succession: Main body/2.5 μm TiAlN/0.6 μm Si 3 N 4 /0.3 μm TiAlN/0.1 μm Si 3 N 4 /0.3 μm TiAlN/0.1 μm Si 3 N 4 .
Comparative Example 2
Like comparative Example 1, but with deposition of a 4.0 μm thick TiAlN layer.
In a milling test carried out as for Example 1 but with a cutting speed v c =283 m/min and a tooth advance f 2 =0.3 mm the following wear mark widths VB were found:
Wear mark width VB
Example 2:
0.10 mm
Comparative Example 2:
0.30 mm | The invention relates to a cutting tool comprising a main part and a multilayer coating applied thereon. A first layer A made of a hard material is applied on the main part, said hard material being selected from titanium aluminum nitride (TiAlN), titanium aluminum silicon nitride (TiAlSiN), chromium nitride (CrN), aluminum chromium nitride (AlCrN), aluminum chromium silicon nitride (AlCrSiN), and zirconium nitride (ZrN), and a second layer B made of silicon nitride (Si3N4) is applied directly over the first layer A. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority to U.S. Provisional Patent Application No. 61/655,205 filed on Jun. 4, 2012, and entitled “COMBINATION HIGH AVAILABILITY CHP AND HIGH DENSITY DATA CENTER,” which is hereby incorporated by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The instant disclosure relates to a power source. The instant disclosure more specifically relates to redundant and highly-reliable power sources for a data center.
BACKGROUND
[0003] Data centers house large amounts of information technology (IT) equipment, such as servers, data storage devices and network equipment. This equipment has the ability to consume power in excess of 600 watts/square foot (SF). To reduce the amount of real estate occupied by the IT equipment, the equipment is stored in racks or enclosures that allow large quantities of equipment to be compressed into small footprints. However, the density, e.g., compaction of the IT equipment, of current data centers is limited by the availability of adequate, redundant, and reliable publically-available electric power to support both the IT equipment and electro-mechanical cooling of the IT equipment. Thus, data center capacity is generally limited by the amount of power that can be provided by the local electrical-utility grid. In stressed areas and in urban environments, the power limit may be in the range of 20 to 25 megavolt-amperes (MVA). However, many high-density data centers have power loads of 180 MVA or greater. In many areas, the public electrical-utility grid cannot supply this quantity of power. Furthermore, data centers, which have become the nerve cluster of many corporations and internet service providers (ISPs), are critical components that must have both power quality and redundancy to prevent data center outages. Thus, even if the public electrical-utility grid could supply sufficient power, the amount of physical space required to provide the necessary power quality and redundancy required would be extremely large and prohibitive in both physical size and cost.
[0004] FIG. 1 is a block diagram illustrating a conventional data center power arrangement. A data center 100 may include connections 102 and 104 to a local electrical-utility grid. The electrical service is supplied to electrical substations 106 and 108 from the connections 102 and 104 , respectively. The electrical power from the substations 106 and 108 simultaneously provide power to information technology (IT) equipment in normal operating conditions. Normal power flow to the IT equipment is from substations 106 and 108 respectively through UPSs 114 and 116 and through the PDUs 118 and 120 , respectively, to remote power panels (RPPs). When public electrical power is lost, generators 110 and 112 may activate to supply electrical power to the IT equipment and prevent loss of service within the data center. Due to the start-up time of the generators 110 and 112 , uninterruptable power supplies (UPS) 114 and 116 are connected in-line between the IT equipment and the generators 110 and 112 . The UPSs 114 and 116 include batteries that provide instantaneous power upon loss of the electrical connections 102 and 104 .
[0005] However, the volume of batteries and supporting equipment increases proportionally to the amount of IT equipment and the load of the IT equipment. For example, the data center 100 must also include paralleling gear coupled to the generators 110 and 112 to support switch-over during public electrical power outages. Furthermore, switches 114 A and 116 A coupled to the UPSs 114 and 116 are necessary to support switch-over during failures of the UPSs 114 and 116 , respectively. Real estate occupied by the batteries and supporting equipment is prohibitive to construction of large high-density data centers. Furthermore, the number and size of the generators 110 and 112 scales with the electrical and cooling load of the IT equipment, which further inhibits development of high-density data centers, as air permitting and space requirements grow with the quantity and size of the generators. Finally, the reliance on public electrical service 102 and 104 and on-site generators 110 and 112 requires the use of complex power conditioning systems, uninterruptable power supplies (UPSs) 114 and 116 , and power distribution units (PDUs) 118 and 120 to condition and distribute power to IT equipment.
SUMMARY
[0006] A data center may be powered by a highly-reliable power plant, which may be configured in a combined heat and power (CHP) plant arrangement, such that the data center does not rely on the public electrical-utility grid for primary or tertiary power supply. The power and cooling distribution from the CHP plant may be in a dual output path configuration to provide redundancy in the power and cooling supplied to the data center. In one embodiment, the data center may be separated into modules that are further segmented into pods, such that power and cooling distribution systems may be segmented for redundancy and availability. In one embodiment, the CHP plant may be co-located with the data center.
[0007] A power plant may improve the fuel source power generation efficiency by using waste heat from generation as output to other processes, which increases the per-British Thermal Unit (BTU) efficiency of the fuel source. Multiple engines, of multiple types, may be configured in the power plant to allow for concurrent maintainability of the power plant components without affecting availability and redundancy during maintenance. In one embodiment, the power plant may have redundant fuel source connections, such that there is no single failure point for the power plant that would reduce availability of the power and cooling to the data center. The engines may be connected to a segmented bus. The bus may be configured as redundant busses with transient surge suppression and power-drop protection and multiple distribution legs for redundancy and diversity.
[0008] On-site electric generation may provide large levels of high-quality electricity to power the data center. On-site electrical generation provides advantages over public utility power, such as allowing for the reduction or elimination of power conditioning equipment and systems in the data center, allowing for the reduction or elimination of all backup diesel generation and fuel oil storage for data center back-up power, increasing power quality as there are no overhead lines subject to interruption or intermediate shorts, reducing voltage sags, harmonics, or power factor correction requirements because there are no other customers to affect power quality, reducing brown-outs or outages due to the electric grid stresses during peak usage periods, reducing public electrical-utility grid transmission and distribution losses, and/or reducing overall environmental emissions because the electric load is generated by natural gas, rather than coal, and the generation plant does not have to produce additional power to overcome typical transmission and distribution losses (estimated at 15% to 20%) and that less overall electricity is required to be produced because the cooling loads are driven by the discharge heat stream, rather than by electric driven motors. A natural gas power plant may have an overall efficiency greater than 75%, while the fossil fuel utility plants have an efficiency of only around 30%. Although natural gas-fired power plants are described herein, other fuel sources may be used at the on-site power plant.
[0009] When the power plant is co-located with the data center, energy losses from the utility generation plant to the site may be reduced or eliminated. The co-location of the power plant may generate a significant savings in the quantity of prime energy required to generate electric power, due to reduction or elimination of typical electric transmission and distribution losses on the local electrical-utility grid.
[0010] In some embodiments, the power plant may produce excess power, which may be sold to the local electrical-utility grid or another off-taker. In one embodiment, the ability to synchronize to the local electrical-utility grid may provide additional system electrical stability. Electrical power flow may be controlled to increase efficiency between the requirements of the data center and the electrical-utility grid. The use of steady mechanical and electrical loads by IT equipment may allow for the optimization of the controls through specialized algorithms accounting for maximizing the production of electricity and chilled water (or steam) over the entire operating range of a data center. For example, on hot days production of chilled water may be favored over steam. In another example, if the electrical load requirements are high and the cooling loads are low, additional power may be generated through steam-driven electric generators. At times when cooling loads are high, compared to the electrical requirements, steam may be diverted to produce additional cooling. Because the cooling plant may be used primarily to cool non-latent loads, the chilled water temperature may be adjusted to provide maximum efficiency and optimum balance for the electric plant.
[0011] In embodiments with a power plant configured in a redundant manner, the electric plant may be configured in an N+y configuration, where N is a number of primary units and y is a number of redundant units. The y redundant units may be operated to provide standby capacity should a loss of any primary unit occur. The y redundant units may also be operated to generate additional electricity for exported to the grid or to local off-takers. At times when excess electrical energy is generated, heat from the prime-mover exhaust discharge may be converted to steam to which will be used to produce additional electric capacity and increase operational efficiency.
[0012] A power plant co-located with a data center may be configured to operate in an islanded mode of operation, in which the power plant maintains the required power quality through the use of various generation components and transient load absorbing components. In this configuration, the power plant may be disconnected from the electrical-utility grid and continue to provide uninterrupted power and cooling to the data center. Furthermore, the exhaust heat from the turbines and engines of the power plant may be recovered through the use of absorption chillers to produce chilled water, further reducing the overall quantity of electrical energy production required by the system through the elimination of electrical driven chillers.
[0013] The use of dedicated electric and chilled water plants allows for the construction of data centers in locations currently prohibited or challenging due to insufficient and/or unaffordable power availability.
[0014] In one embodiment, an apparatus may include a combined heat and power (CHP) plant having redundant power sources and/or provide redundant power generation. For example, the CHP plant may have dual diverse natural gas inputs. In another example, the CHP plant may have redundant engines and turbines for generating power. The redundant power sources, either at the input of the CHP plant or within the CHP plant, reduce the likelihood of a single-point failure within the CHP plant. The apparatus may also include a data center coupled to the power plant. The data center may be co-located with the power plant on the same physical property.
[0015] In a further embodiment, a method may include receiving a first fuel source. The method may also include receiving a second fuel source different from the first fuel source. The method may further include generating electrical power from at least one of the first fuel source and the second fuel source in a plant co-located with a data center. The method may also include providing the electrical power to the data center.
[0016] The foregoing has outlined rather broadly certain features and technical advantages of embodiments of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter that form the subject of the claims. It should be appreciated by those having ordinary skill in the art that the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same or similar purposes. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features that are believed to be characteristic, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a more complete understanding of the disclosed system and methods, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.
[0018] FIG. 1 is a block diagram illustrating a conventional data center power arrangement.
[0019] FIG. 2 is a block diagram illustrating a system with a data center co-located with a combined heat and power (CHP) power plant according to one embodiment of the disclosure.
[0020] FIG. 3 is a block diagram illustrating connections within a system with a data center co-located with a combined heat and power (CHP) plant according to one embodiment of the disclosure.
[0021] FIG. 4 is a block diagram illustrating a configuration of N natural gas turbines and M engines to produce electricity in a redundant manner according to one embodiment of the disclosure.
[0022] FIG. 5 is a block diagram illustrating cooling a module of a data center according to one embodiment of the disclosure.
[0023] FIG. 6 is a block diagram illustrating electrical distribution within each pod according to one embodiment of the disclosure.
DETAILED DESCRIPTION
[0024] A combined heat and power (CHP) plant may include both electrical and mechanical services. At capacity, the generated electric load and the electric cooling load requirements of a data center may be balanced against the electrical and mechanical services of the CHP plant and provide upward of 75% overall power plant efficiency. This high efficiency may be achieved, for example, through the use of selective heat recovery equipment on the exhaust stream from the turbine and engine generation equipment.
[0025] FIG. 2 is a block diagram illustrating a system with a data center co-located with a combined heat and power (CHP) power plant according to one embodiment of the disclosure. In a system 200 with a power plant 302 co-located with a data center 312 , the data center 302 may provide two independent electric service buses 306 A and 306 B. The electric service buses 306 A and 306 B may be coupled to electric substations 204 A and 204 B, respectively. A distribution system 202 may be coupled to the substations 204 A and 204 B for distributing power received from the power plant 302 to IT equipment.
[0026] FIG. 3 is a block diagram illustrating a system 300 with a data center co-located with a combined heat and power (CHP) plant according to one embodiment of the disclosure. The power plant 302 may provide chilled water 304 A and 304 B to a data center 312 . Although two redundant water supplies 304 A and 304 B are shown, additional chilled water supplies may be provided to the data center 312 . The power plant 302 may also provide electric service 306 A and 306 B to the data center 312 . Although two electric service connections 306 A and 306 B are shown, additional electric service connections may be provided to the data center 312 . Furthermore, the power plant 302 may provide a steam connection 308 to the data center 312 for heat, humidification and/or other electro-mechanical generation. The power plant 302 may also provide a steam connection 342 and electrical connection 344 to a third-party off-taker for heat and/or other electro-mechanical generation. In one embodiment, the connection 344 may provide an output to sell electric power to other customers in close proximity not requiring connection to the electric grid.
[0027] An exhaust gas stream 342 of a power plant 302 may be used to produce steam of sufficient quantity and pressure to drive additional electric generation or for process uses or comfort heating to third-party off takers. The remaining heat, not used in the direct production of additional electricity or chilled water, may be used to pre-heat boiler make-up and for other minor heating loads. Overall the efficiency of the system may be as high or greater than 75% efficient due to the significant and stable cooling requirements of the high-density data center.
[0028] The power plant 302 may include a number of natural gas-driven generation units, embodied as a combination of turbines and engine generators, power conditioning devices (PCDs), heat recovery boilers, embodied as either steam or hot water generating units, steam turbine driven generators, and/or absorption chillers, configured in a redundant and concurrently maintainable configuration.
[0029] The power plant 302 and the data center 312 may be a single assembly with a closely-coupled arrangement between the data center 312 and the output of the power plant 302 . Auxiliary power and cooling production may be optimized to allow greater use of waste heat and provide optimum control over power and cooling though the implementation of proprietary control schemes.
[0030] The power plant 302 may be coupled to fuel sources through a first natural gas source 322 and a second natural gas source 324 . The two natural gas sources 322 and 324 may couple to independent natural gas stations, such that the availability of uninterrupted natural gas is increased. The power plant 302 may also include a connection 326 to a local electrical-utility grid for either importing or exporting electricity. The natural gas may be supplied from diversely-routed services, each capable of providing full-load capacity in case of a supply disturbance. Although natural gas sources are described herein, other sources of fuel may be provided instead of or in addition to natural gas, such as propane, methane, gasoline, and/or diesel. Likewise, water to the power plant 302 may be provided through two sources 328 and 330 , which may be two independent connections from diversely-routed sources, which may include a self-contained well near the power plant 302 .
[0031] In one embodiment, the only energy input to the site 300 may include the dual diverse natural gas services 322 and 324 . The connection 326 may provide an output to sell electric power to other customers and to provide a synchronizing source for the generated power. The connection 326 may provide a black-start capability to the utility grid, VAR, voltage reinforcement or capacity enhancement. A metering system may be coupled to the connection 326 or the connection 344 to measure power provided to other customers or power provided to the local electrical-utility grid.
[0032] The power plant 302 may also provide a CO 2 output 346 . In one embodiment, the connection 346 may provide an output to collect and refine the emitted CO 2 from the exhaust gas stream and produce high quality CO 2 gas for industrial and food applications.
[0033] In one embodiment, the data center 312 may provide a connection 348 for low-grade heat. The low-grade heat may be provided or sold to third-party off-takers, such as for greenhouses, aquaponics and/or hydroponics applications.
[0034] FIG. 4 is a block diagram illustrating a configuration of N natural gas turbines and M engines to produce electricity in a redundant manner according to one embodiment of the disclosure. A power plant 410 may include N turbines 412 and M engines 422 . The turbines 412 and engines 422 may provide power to electrical buses 432 and 434 . The turbines 412 and engines 422 may also provide exhaust output to one or more heat recovery units 442 , such as boilers. The heat recovery units may produce steam for powering one or more absorption chillers 448 and/or one or more steam turbines 450 to generate additional power for electrical buses 432 and 434 . In one embodiment, the heat recovery units 442 may be integrated with the absorption chillers 448 .
[0035] The engines 422 may provide response to changes in load more rapidly than the turbines 412 . Each engine 422 may provide distribution to alternate electrical buses 432 and 434 , such that a failure on one bus will not affect the other bus. Heat from the exhaust gas stream from both the turbines 412 and the engines 422 may be recovered in the form of steam and hot water. Steam may be produced at high pressure to drive additional electric generation, such as at the turbines 446 . Heat from the turbines 412 and the engine exhaust may be recovered and delivered to absorption chillers 448 to produce chilled water. Additionally, hot water may be extracted from the remaining discharge gas stream and may be reclaimed to preheat boiler feed water or some space heating use.
[0036] The power plant 410 provides diverse electrical services to a data center. Multiple engines 422 interfaced through multiple buses 432 and 434 may allow for redundant and resilient configurations providing alternate paths should one path become unavailable. The distribution buses 432 and 434 may include minimal surge suppression and power conditioning equipment to support changes in the bus voltage and frequency. The power plant 410 may have the capability of exporting excess power to a local electrical-utility grid when power production exceeds the amount consumed by the data center. In one embodiment, steam may be extracted from an intermediate stage of the steam turbine to provide minimum humidification to the data center and, depending on actual data center load, steam may be exported to additional off-takers.
[0037] A mechanical plant may include a combination of absorption chillers and centrifugal chillers configured in a dual-bus arrangement. Electric-driven centrifugal chillers (not shown) may supplement the absorption chillers 448 when additional cooling load is desired and for quick response to changes in the cooling load. During periods when the data center cooling loads are reduced, such as during winter and shoulder periods, the steam and hot water may be exported to local non-data center users. In climates where the full-load operating hours of the chiller plant are low and the humidity levels are within tolerance, the chiller loads may be displaced with refrigerant systems.
[0038] A data center may be configured in a modular configuration where multiple modules are constructed. FIG. 5 is a block diagram illustrating a module of a data center according to one embodiment of the disclosure. Each module 502 may be comprised of a number of smaller enclosures, such as pods 504 A and 504 B. In certain embodiments, there may be as many as 16 pods in one module. Each of the pods 504 A and 504 B may operate at different power densities and cooling levels depending on specific client requirements. The pods 504 A and 504 B may include IT equipment, such as network equipment, routers, switches, storage nodes, and/or servers. The primary cooling for the high-density data center may include filtration of outside air and this air may be ducted into the data center based on proper outside air conditions. In the embodiment of FIG. 5 , the pods 504 A and 504 B may be cooled through redundant chilled water connections 512 and 514 coupled to air handlers, or heat exchangers 522 A and 522 B, respectively. The water connections 512 and 514 may include both a supply path 512 A and 514 A and a return path 512 B and 514 B, respectively.
[0039] Although not shown, in one embodiment the pods 504 A and 504 B may be cooled through the use of DX, or similar, non-water cooled, systems, thereby allowing additional electrical power and steam production depending on the requirements of the specific installation.
[0040] Electrical service may also be distributed in a pod system as described with cooled water in FIG. 5 . FIG. 6 is a block diagram illustrating electrical distribution with each pod according to one embodiment of the disclosure. Redundant electrical buses 612 and 614 may provide redundant and independent sources of electric power to IT equipment in each of the pods 504 A and 504 B. Within the pods 504 A and 504 B, IT equipment may be arranged on racks, such as rack 622 , which includes a connection to the buses 612 and 614 .
[0041] Although the present disclosure and certain of its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the present invention, disclosure, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | A power plant, in the form of a combined heat and power (CHP) plant, may be co-located with a data center to provide redundant electrical power. The CHP plant and the data center may operate as an island, separate from the local electrical-utility grid. The CHP plant may have a redundant fuel source connection to reduce unavailability of fuel for the CHP and increase the uptime of the data center. The CHP plant may include turbines and engines to manage variable loads within the data center. The power plant may include multiple distributions busses in high-availability configurations to provide highly-reliable and high-quality electricity to the data center. The positioning of these elements in the power plant design provides economies of scale and eliminates single points of failure commonly found in data center configurations, increasing the reliability of the data center. | 5 |
FIELD OF THE INVENTION
The present invention relates to a brake disc for vehicles; in particular, the present invention relates to brake discs that are suitable for being used on motorcycles.
BACKGROUND OF THE INVENTION
As we know, in some motorcycles the front or back wheels often comprise an integrally formed brake disc, in other words comprising a portion for connecting to the hub, a braking band and a plurality of spokes made in a single piece.
During braking, these brake discs may suffer vibrations that cause an irritating whistling.
Solutions suitable for eliminating this inconvenience are not known in the art.
SUMMARY OF THE INVENTION
The problem of the present invention is to make a brake disc for vehicles that resolves the inconveniences stated with reference to the prior art.
These inconveniences are resolved by a brake disc for vehicles as described below.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the present invention will be appreciated from the following description of a preferred embodiment, wherein:
FIG. 1 represents a perspective view of a brake disc according to an embodiment of the present invention;
FIG. 2 represents a front view of the disc in FIG. 1 , from the side of the arrow II in FIG. 1 ;
FIG. 3 represents a front view of a brake disc according to a further embodiment of the present invention;
FIG. 4 represents a perspective view with separate parts of a disc according to a further embodiment of the present invention;
FIG. 5 represents a front view of the disc in FIG. 4 , from the side of the arrow V in FIG. 4 ;
FIG. 6 represents a section view of the disc in FIG. 5 , along the VI-VI section line in FIG. 5 ;
FIG. 7 represents a perspective view with separate parts of a brake disc according to a further embodiment of the present invention;
FIG. 8 represents a perspective view of the disc in FIG. 7 in an assembly configuration, from the side of the arrow VIII in FIG. 7 ;
FIG. 9 represents a perspective view of the disc in FIG. 7 in an assembly configuration, from the side of the arrow IX in FIG. 7 ;
FIG. 10 represents a perspective view of a disc according to a further embodiment of the present invention;
FIG. 11 represents a front view of the disc in FIG. 10 , from the side of the arrow XI in FIG. 10 ;
FIG. 12 represents a section view of the disc in FIG. 10 , along the XII-XII section line in FIG. 11 ;
FIG. 13 represents a perspective view of a disc according to a further embodiment of the present invention;
FIG. 14 represents a front view of the disc in FIG. 13 , from the side of the arrow XIV in FIG. 13 ;
FIG. 15 represents a section view of the disc in FIG. 13 , along the XV-XV section line in FIG. 14 .
DETAILED DESCRIPTION OF THE INVENTION
The elements or parts of elements in common between the subsequently described embodiments will be indicated with the same numeral references.
The term radial direction means a direction that is substantially perpendicular to an X rotation axis of the disc.
The term axial direction means a direction that is substantially parallel to the X rotation axis of the disc.
The term tangential direction means a direction that is substantially perpendicular to the axial direction and to the radial direction.
With reference to the above drawings, a brake disc for vehicles with an X rotation axis is generally indicated with reference numeral 4 .
The brake disc 4 comprises a connecting portion 8 to a wheel hub of a vehicle, a braking band 12 and at least one spoke 16 interconnecting the connecting portion 8 and the braking band 12 .
The braking band 12 is preferably connected to the connecting portion 8 by means of a plurality of spokes 16 that are preferably arranged in step.
The brake disc 4 is formed integrally, in particular, the braking band 12 is integral with the connecting portion 8 and with the spokes 16 .
Advantageously, at least one spoke 16 comprises an active section reduction 18 to provide reduced rigidity in relation to the corresponding integral section.
According to an embodiment of the present invention, the section reduction 18 is made with a lightening 19 that is suitable for reducing the axial thickness of a portion of the spoke.
According to one embodiment ( FIGS. 11 , 12 ), the lightening 19 has a tangential course that is sufficient to influence the whole tangential width of the spoke 16 . The lightening 19 can be defined by one or more chamfers or flares 20 , which are arranged tangentially and parallel between each other.
According to a further embodiment ( FIGS. 13-15 ), the lightening 19 has a circular course defining a cylindrical pocket.
The lightening 19 with a circular course is preferably defined by a chamfer or flare 20 arranged on the side of one face of the disc.
The lightening 19 preferably limits the active section of the spoke 16 to maintain the continuity, level with said spoke 16 , between the connecting portion 8 and the braking band 12 . In other words, the lightening 19 reduces the active section of the spoke 16 but does not completely interrupt the continuity of the same spoke, or rather the mechanical connection that the spoke forms between the braking band 12 and the connecting portion 8 .
The lightening 19 preferably reduces the active section of the spoke 16 to no more than 40% of the active section of the integral spoke 16 . In other words, the lightening 19 reduces the active section of the spoke 16 by at least 60% compared with the corresponding section of the integral spoke 16 .
According to an advantageous embodiment ( FIGS. 1-5 ), the section reduction 18 creates an interruption 22 of the spoke 16 so as to divide the spoke 16 into two parts and interrupt the continuity between the connecting portion 8 and the braking band 12 .
According to an embodiment, the interruption 22 is arranged level with a portion of the spoke 16 next to the braking band 12 .
According to an embodiment, the interruption 22 comprises a direct channel 24 that is substantially tangential to the braking band 12 so as to affect the whole tangential thickness of the spoke 16 dividing it into two separate parts.
The interruption 22 preferably comprises at least one indentation 28 in relation to a radial direction, which is suitable for defining a slot 32 with said channel 24 .
According to an embodiment, the interruption 22 comprises a pair of indentations 28 that are radially facing and arranged on each of the ends of the opposite portions of the spoke 16 facing each other, the indentations 28 defining a slot 32 with the channel 24 .
The slot 32 is preferably symmetrical in relation to a radial direction passing the X rotation axis of the disc 4 .
The slot 32 is also preferably symmetrical in relation to a tangential direction, perpendicular to a radius of the disc.
According to an advantageous embodiment, the disc 4 comprises at least one bush 40 contained in the slot 32 and the channel 24 so it is constrained by the indentations 28 in relation to a tangential direction.
According to an embodiment, the bush 40 comprises a bush body 44 and constraining means 48 . According to an embodiment the bush 40 is formed integrally and level with an axial end, said constraining means comprise a first head 50 , and at the opposite end they comprise a second head 51 , which is obtained, for example, by riveting. These heads 50 , 51 exhibit a greater diameter than the diameter of the slot 32 so as to axially constrain the bush 40 in relation to the slot 32 .
An elastic element 52 is preferably inserted between the bush body 44 and one of the heads 50 , 51 , suitable for pre-charging the bush body 44 and the constraining means 50 , 51 in relation to an axial direction.
According to an embodiment, said elastic element 52 is a washer spring.
The mass of the bush 40 is preferably substantially equal to the mass of material removed from the spoke 16 to form the interruption.
According to a further embodiment, the disc comprises at least one small plate 60 suitable for being connected to the slot 32 or the channel 24 so as to cover the interruption 22 at least partially.
The small plate 60 preferably has a plate body 64 , for example that is flat and equipped with a pair of fastening flaps 68 that are suitable for being constrained by clicking or mortising to special fastening holes 72 , which are arranged, for example, on the spoke on the side of the connecting portion 8 and the braking band 12 .
According to an embodiment, the plate body 64 comprises two flaps 76 suitable for being hooked by clicking onto side edges 78 of the spoke, which are separated by the interruption 22 .
The plate body 64 preferably has a tangential extension so as to completely cover the interruption 22 .
The mass of said plate 60 is preferably substantially equal to the mass of material removed from the spoke 16 to form the interruption 22 .
Advantageously, in an assembly configuration of the disc 4 on the relative wheel hub, the disc is oriented angularly to bring the interruption 22 and the connectable bush 40 or plate 60 into a diametrically opposite position in relation to the inflation valve of the relative tyre to be connected to the rim.
According to a further embodiment, at least two spokes 16 of the disc 4 comprise an active section reduction 18 to exhibit reduced rigidity in relation to the corresponding integral section.
Said active section reduction 18 can be made with a lightening 19 or an interruption 20 . In an embodiment comprising two spokes 16 , with an active section reduction 18 , said spokes 16 are preferably arranged in diametrically opposite positions in relation to said X rotation axis of the disc 4 .
In an embodiment comprising at least two spokes 16 or a plurality of spokes 16 , comprising an active section reduction 18 , the spokes 16 , comprising an active section reduction 18 are preferably arranged in step in relation to the X rotation axis.
As we can appreciate from the description, the brake disc of the present invention enables the inconveniences exhibited by the brake disc of the prior art to be overcome.
In particular, the disc according to the invention does not vibrate and whistle during braking.
The disc in the present invention maintains a gyroscopic effect, as well as a reduced, non suspended mass.
In order to satisfy specific and contingent needs, a person skilled in the art can make numerous modifications and variations to the above described brake discs, all of which are included in the scope of the invention, as defined by the following claims. | A brake disc of the type comprising a braking band, a connecting portion and connecting spokes made in a single piece. In said disc at least one spoke exhibits an active section reduction that is sufficient to prevent vibrations and whistling during the braking phase. The disc, according to the present invention, is not subject to vibrations and possesses a limited gyroscopic effect and mass. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to the construction of a brick facing, and in particular to improvements in the components used in securing the thin brick facing onto a building structure.
As is well known, thin bricks are used in place of standard bricks to create a brick facing on building structures. These exterior brick surfaces are not intended to be load bearing, and primarily serve an aesthetic function. The use of standard load bearing bricks can be expensive in that the bricks themselves, being larger, require additional material in forming. Further, laying standard sized bricks requires highly trained masons who have developed expertise in brick laying. The process is time-consuming, and most individuals lack the requisite skills.
Thin bricks have the advantage of being easier to install. Generally, the assemblies have an insulation board or backing board to which thin bricks are mounted. The backing board is attached to supporting structure on the building and mortar is then applied in the joints between the bricks. In one type of system, brick panels are pre-fabricated by gluing the thin bricks to the backing board. The pre-fabricated brick panels are then transported to the job site to be attached to the building. This type of system is disclosed in U.S. Pat. No. 4,407,104.
In the assembly disclosed in the '104 patent, support clips connect the brick assembly to the underlying building support structure. The brick tile facing, through the use of these clips, can then be supported independent of the backing member. Although commercially successful, a disadvantage of this system is that the pre-fabricated brick panels are difficult to transport, and are difficult to cut into desired shapes. Use of pre-fabricated brick panels is particularly undesirable for a person doing smaller home-improvement projects.
As an alternative, attempts have been made to provide a more manageable system adjusted particularly for the home-improvement user. A system that has smaller disassembled pieces which can be packaged more easily and assembled at the job site. Such a brick facing system can be constructed at less cost, and the individual components are transported more easily.
One such attempt at providing a brick panel system requiring assembly includes a backing member having an insulation layer and a separate plastic face which must be attached to the insulating layer. See U.S. Pat. No. 4,809,470. The plastic face contains channels for aligning brick tiles into rows. These two layer backing members are more complicated and thereby more costly to produce than a backing member formed of a single material. Also, the channels are believed to be more rigid and less receptive to bricks having varying widths which is sometimes a problem.
The use of a backing member formed from a single sheet of material is known. Great Britain Patent GB 1478863 discloses a backing member formed from a foam insulation sheet which includes channels formed directly in the sheet. The channels are adapted to retain individual brick tiles. The channels further include projections which extend transversely into an adjacent channel to provide resistance to hold the brick tile.
The difficulty with this type of panel is that the transversely extending projections can cause difficulties with placing the thin brick tile fully into the channel. If the brick tiles do not lay uniformly and properly within the channel of the backing member, the completed brick wall will have an uneven, undesirable finish.
It is therefore an object of this invention to provide an improved backing member adapted to uniformly retain standard thin brick tiles, the backing member being formed of a single insulating sheet which can be easily and inexpensively formed in mass production. It is a further object of this invention to provide a support clip which can be used in conjunction with this backing member to easily connect the insulating sheet to an underlying support structure and which when mortared will directly connect the bricks to the underlying structure.
SUMMARY OF THE INVENTION
The present invention discloses improvements in constructing a brick facing on a building structure. The brick facing assembly includes an improved backing member adapted to retain thin brick tiles within channels, and improved support clips which are used to initially secure the backing member and ultimately the completed brick facing to an underlying support structure of the building.
The backing member is formed from a single sheet of material which has channels cut directly into an insulation layer in order that rectangularly-shaped thin brick tiles may be received uniformly throughout each channel. Support clips in the channels have direct contact with the thin brick tile, and extend into the mortar area. The support clips are fastened to an underlying support structure of the building. The thin brick tiles are easily placed flat against the uniformly smooth area of the channel which is adjacent to the rear surface of the thin brick tile. Mortar is then placed between the individual brick tiles to form the brick facing. The support clips extend into the mortar.
The backing member includes parallel holding guides which extend outwardly to define the channels. One side of the holding guide is generally perpendicular to the insulate base, and provides for facial contact with an adjacent thin brick tile. Another side of the holding guide is under-cut so that the side is angled outwardly towards the channel. The under-cut side provides a knife-like edge for line contact with adjacent thin brick tiles. The arrangement allows for a thin brick tile to be snapped into the channel, having enough resistance to hold the thin brick tile, but not so much resistance as to prevent the thin brick tile from being fully received in the channel.
Further, the backing member has a substantially identical cross-section along its entire length allowing channels to be cut into an original sheet by a hot wire cutting process. With this design, the backing member can be easily and cost effectively mass produced.
Support clips are used to directly connect the brick facing to the building structure. The support clips include a rear plate which is disposed between a brick tile and the backing member and which extends along a back surface of the thin brick tile. A shelf extends from an edge of the rear plate to provide direct vertical support for the brick tile. Teeth extend from an edge of the shelf into the mortar area between individual brick tiles. The teeth are spaced from each other to provide a locking means for the support clip to be solidly embedded into the mortar area.
These and other features of the present invention can best be understood from the following specification and drawings, of which the following is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the thin brick panel assembly.
FIG. 2 is a front view of a completed brick facing incorporating the present invention.
FIG. 3 is a cross-sectional view substantially along line 3--3 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-3, an inventive thin brick panel assembly 20 includes a backing member 22, support clips 24 and individual thin brick tiles 26. Mortar 28 is applied along the area between the thin brick tiles 26 to form a brick facing 30. Support clips 24 are used during assembly to initially anchor the backing member 22 and ultimately the completed brick facing 30 to the underlying building structure 32.
The backing member 22 is formed from a single sheet of material. Backing member 22 includes an insulate base 34 and generally parallel holding guides 36 which extend outwardly from and are integral to the insulate base 34. The holding guides 36 are spaced to define channels 38. One side 39 of the holding guide 36 is angled to form a knife edge 40 which extends into adjacent channel 38. Knife edge 40 retains thin brick tiles 26 within channel 38, and also allows accommodation of tolerances in the size of thin brick tiles 26. Another side 41 of the holding guide 36 is generally perpendicular to the insulate base 34. A generally vertical groove 43 is formed in backing member 22 to allow water to drain. The groove 43 is preferably on 16 inch centers and has a depth of 1/8 inch into the channel 38. As should be understood, the groove 43 extends through sides 39 and 41 as well as into backing member 22 1/8 inch.
The channels 38 of the backing member 22 are formed by cutting directly into an original sheet of insulation material. The knife edge 40, in particular, is formed by cutting side 39 of the holding guide 36 at an angle inwardly from a top portion of the holding guide 36. Side 39, having the knife edge 40, forms an acute angle with the channel 38. This design permits knife edge 40 to have line contact with a shin brick tile 26, in order to provide sufficient resistance to retain a thin brick tile 26 within channel 38, but not excessive resistance which would prevent channel 38 from fully receiving the brick tile 26. This knife edge 40, in connection with a standard thin brick tile, permits the thin brick tile 26 to "snap" into channel 38.
The channel 38 is generally uniform and flat along the area defined by insulate base 34, which is adjacent to the back portion 42 of a thin brick tile 26. This also assures that thin brick tiles 26 lay uniformly within channels 38.
In constructing the brick facing 30, the pre-cut backing member 22 is first positioned along the building structure 32. Support clips 24 are then placed on an outer surface 44 of backing member 22 in, for example, a pattern illustrated in FIG. 3, and are attached by a fastening means 46, such as a nail. The fastening means 46 passes through backing member 22 into the building structure 32, allowing support clip 24 to remain on the outer surface 44 adjacent to thin brick tile 26. In addition to securing the backing member 22, support clip 24 provides a means for the brick facing 30 to be directly attached to the building structure 32 independent of the backing member 22. This is accomplished by having portion 51 of the support clip 24 extend into the area between individual thin brick tiles 26 which receives mortar 28. This will be discussed in greater detail below.
In order to insert the thin brick tiles 26 into channels 38, the thin brick tiles 26 are first placed against side 41 of the holding guide. The thin brick tile 26 is then snapped completely into the channel 38, causing knife edge 40 to deform slightly. In the preferred method of assembly, glue is applied to the bricks or channel to ensure that the bricks 26 are secured in channel 38. Mortar 28 is then applied to the area between thin brick tiles 26, embedding portion 51 of support clip 24. Once mortar 28 is set and hardened, the brick facing 30 is secured through the clip 24 to the building structure 32.
The support clip 24 includes a rear plate 50 which is intended to be disposed between the thin brick tile 26 and backing member 22. In the preferred embodiment, Rear plate 50 extends greater than one-half the distance of the back portion 42 of thin brick tile 26. A shelf 52 extends from an edge of rear plate 50 and abuts side 41 of the holding guide 36. Shelf 52 has facial contact with a portion of thin brick tile 26 and provides direct vertical support. The rear plate 50 and shelf 52 combine to provide significant direct facial contact with the thin brick tile 26, proving firm support. Portion 51 includes teeth 56 which extend from an edge of shelf 52 into the mortar area between individual brick tiles 26. Teeth 56 are alternately angled from shelf 52 to form rows, allowing the teeth in each row to be spaced from each other, and to resist loads applied to the brick facing 30. Each tooth 56 is embedded in the mortar 28 on three sides to ensure that portion 51 is locked into the mortar 28.
The backing member 22 has a longitudinal dimension defined by the holding guides 36 extending along a longitudinal axis and has a uniform cross-section along the entire longitudinal dimension. Since backing member 22 has a uniform cross-section along the entire longitudinal dimension, channels 38 can be cut directly into the original sheet of material by a hot wire cutting process. This design and process allows the backing member 22 to be easily and inexpensively mass produced.
Preferably, backing members 22 includes tongue and groove joints along the edges to improve structural integrity. Each backing member 22 includes a tongue 58 extending from one edge. An adjacent backing member 22 includes a groove 60 on a corresponding edge which aligns to receive tongue 58.
Preferably, the original sheet of material forming the backing member 22 is extruded polystyrene. In one embodiment, the insulate base 34 is approximately 3/4 inches thick, the holding guides 36 extend approximately 3/16 inch from the insulate base 34 and the thin brick tile 26 is approximately 1/2 inch thick, providing approximately 5/16 inch of thickness for mortar 28. The support clips 24 are formed of metal.
A preferred embodiment of the present invention has been disclosed. A worker of ordinary skill in the art, however, would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied in order to determine the true scope and content of this invention. | A thin brick panel assembly for forming a brick facing on a building includes a backing member formed from of a single sheet of material which is adapted to properly retain individual thin brick tiles, and support clips utilized in supporting the completed brick facing. The backing member has a uniform cross-section throughout its entire length, and provides channels which allow the thin brick tiles to lay uniformly across each row. Support clips secure the completed brick facing to an underlying support structure of the building. | 4 |
The present invention relates to novel benzamide, heteroarylamide and reverse amide, processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them, and their use in therapy. The active compounds of the present invention are useful in the treatment of inflammatory diseases such as osteoarthritis and rheumatoid arthritis; allergies, asthma; COPD, cancer, reperfusion or ischemia in stroke or heart attack, autoimmune diseases and other disorders. The active compounds are also antagonists of the P2X 7 receptor.
The P2X 7 receptor (previously known as P2Z receptor), which is ligand-gated ion channel, is present on a variety of cell types, largely those known to be involved in the inflammatory/immune process, specifically, macrophages, mast cells and lymphocytes (T and B). Activation of the P2X 7 receptor by extracellular nucleotides, in particular adenosine triphosphate, leads to the release of interleukin-1β (IL-1β) and giant cell formation (macrophages/microglial cells), degranulation (mast cells) and proliferation (T cells), apoptosis and L-selectin shedding (lymphocytes). P2X 7 receptors are also located on antigen-presenting cells (APC), keratinocytes, salivary acinar cells (parotid cells), hepatocytes and mesangial cells.
P2X 7 antagonists are known in the art, such as International Patent Publications WO 01/46200, WO 01/42194, WO 01/44213, WO99/29660, WO 00/61569, WO 99/29661, WO 99/29686, WO 00/71529, and WO 01/44170.
Benzamides, heteroarylamides and reverse amides for uses other than inhibition of P2X 7 have been published, such as International Patent Publications WO 97/22600, EP 138,527, WO 00/71509, WO 98/28269, WO 99/17777 and WO 01 58883.
SUMMARY OF THE INVENTION
The present invention relates to a compound of the formula
wherein A is —(C═O)NH— or —NH(C═O)—;
X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═(CR 8 )—; or ═N—, ═(CR 7 )—, and ═(CR 8 )—; or ═(CR 6 )—, ═N—, and ═(CR 8 )—; or ═(CR 6 )—, ═(CR 7 )—, and ═N—; or ═N—, ═(CR 7 )—, and ═N—; or ═(CR 6 )—, ═N—, and ═N—; or ═N—, ═N— and ═(CR 8 )—; respectively;
R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl containing one to six heteroatoms independently selected from —N═, —N<, —NH—, —O— and —S(O) n —; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl is substituted by at least one oxo group or one of said heteroatoms is —S(O) n —, wherein n is one or two; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any carbon atom able to support additional substituents, by one R 9 (preferably 1–8 R 9 groups per ring, more preferably 1–3 R 9 groups per ring), each R 9 is independently selected from the group of suitable substituents, such as hydrogen, halo, hydroxy, —CN, HO—(C 1 –C 4 )alkyl, (C 1 –C 4 )alkyl optionally substituted with one to three fluoro, (C 1 –C 4 )alkoxy optionally substituted with one to three fluoro, HO 2 C—, (C 1 –C 6 )alkyl-O—(C═O)—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(C═O)—, R 4 R 5 N(CH 2 ) t —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 ) heterocyclyl-O—; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any ring nitrogen atom able to support an additional substituent by one to two R 10 groups per ring, each R 10 is independently selected from the group of suitable substituents such as hydrogen, (C 1 –C 4 )alkyl optionally substituted with one to three fluoro, (C 1 –C 4 )alkyl-(C═O)—, (C 1 –C 4 )alkyl-SO 2 —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 9 and R 10 substituents may optionally be substituted on any ring carbon atom by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 ) alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
n is an integer from zero to two;
q is an integer one or two;
s is an integer from one to three;
t is an integer from zero to three;
R 2 is chloro, bromo, (C 1 –C 4 )alkyl, —CF 3 or —CN;
R 3 is selected from the group consisting of (C 4 –C 10 )alkyl, (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —, (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s —; wherein said (C 4 –C 10 )alkyl may optionally be independently substituted with one to three suitable substituents such as halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of said R 3 group members (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — contain one to three heteroatoms independently selected from —0— and —S(O) n —; wherein each of said R 3 group members (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —, (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—, (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — may optionally be substituted on any carbon atom able to support an additional independent suitable substituent, by one to four substituents per ring, such as halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, benzyl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said R 3 group members (C 3 –C 8 )cycloalkyl-(CR 11 R 12 ) s — and (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — may also optionally be substituted by oxo; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 3 substituents may optionally be substituted on any ring carbon atom by one to three independent suitable moieties per ring, such as halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 —N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle;
R 6 , R 7 and R 8 are each independently selected from the group consisting of hydrogen, halogen, cyano, hydroxyl, (C 1 –C 6 )alkyl optionally substituted by one to four chloro or fluoro, and (C 1 –C 6 )alkyloxy optionally substituted by one to four chloro or fluoro;
R 11 and R 12 are each independently selected from the group consisting of hydrogen, fluoro, cyano, hydroxyl, —CF 3 , CF 3 O—, (C 1 –C 6 )alkyl, (C 3 –C 8 )cycloalkyl, (C 1 –C 6 )alkyloxy, (C 3 –C 8 )cycloalkyloxy, phenyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein said (C 1 –C 6 )alkyl, (C 3 –C 8 )cycloalkyl, (C 1 –C 6 )alkyloxy, (C 3 –C 8 )cycloalkyloxy, phenyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl may optionally be substituted by one to three suitable substituents such as independently selected from chloro, fluoro, cyano, hydroxyl, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, or (C 1 –C 4 )alkyl-(C═O)—,
with the proviso that when said R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) 5 —; R 1 and R 2 are each hydrogen; and s is one or two; then said (C 3 –C 12 )cycloalkyl must be other than optionally substituted adamantyl;
or the pharmaceutically acceptable salts or solvates or prodrugs thereof.
The present invention also relates to the pharmaceutically acceptable acid addition salts of compounds of the formula I. The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as the chloride, bromide, iodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, acetate, lactate, citrate, acid citrate, tartrate, bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate [i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)]salts.
The invention also relates to base addition salts of formula I. The chemical bases that may be used as reagents to prepare pharmaceutically acceptable base salts of those compounds of formula I that are acidic in nature are those that form non-toxic base salts with such compounds. Such non-toxic base salts include, but are not limited to those derived from such pharmacologically acceptable cations such as alkali metal cations (e.g., potassium and sodium) and alkaline earth metal cations (e.g., calcium and magnesium), ammonium or water-soluble amine addition salts such as N-methylglucamine-(meglumine), and the lower alkanolammonium and other base salts of pharmaceutically acceptable organic amines.
This invention also encompasses pharmaceutical compositions containing prodrugs of compounds of the formula I. Compounds of formula I having free amino, amido, hydroxy or carboxylic groups can be converted into prodrugs. Prodrugs include compounds wherein an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues which are covalently joined through peptide bonds to free amino, hydroxy or carboxylic acid groups of compounds of formula I. The amino acid residues include the 20 naturally occurring amino acids commonly designated by three letter symbols and also include, 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline, homocysteine, homoserine, ornithine and methionine sulfone. Prodrugs also include compounds wherein carbonates, carbamates, amides and alkyl esters which are covalently bonded to the above substituents of formula I through the carbonyl carbon prodrug sidechain.
This invention also encompasses compounds of formula I containing protective groups. One skilled in the art will also appreciate that compounds of the invention can also be prepared with certain protecting groups that are useful for purification or storage and can be removed before administration to a patient. The protection and deprotection of functional groups is described in “Protective Groups in Organic Chemistry”, edited by J. W. F. McOmie, Plenum Press (1973) and “Protective Groups in Organic Synthesis”, 2nd edition, T. W. Greene and P. G. M. Wuts, Wiley-Interscience (1991).
The compounds of this invention include all stereoisomers (e.g., cis and trans isomers) and all optical isomers of compounds of the formula I (e.g., R and S enantiomers), as well as racemic, diastereomeric and other mixtures of such isomers.
The compounds, salts and prodrugs of the present invention can exist in several tautomeric forms, including the enol and imine form, and the keto and enamine form and geometric isomers and mixtures thereof. All such tautomeric forms are included within the scope of the present invention. Tautomers exist as mixtures of a tautomeric set in solution. In solid form, usually one tautomer predominates. Even though one tautomer may be described, the present invention includes all tautomers of the present compounds. One example of a tautomeric structure is when R 1 is a group of the formula
One skilled in the art will appreciate that this group can also be drawn as its tautomer
The present invention also includes atropisomers of the present invention. Atropisomers refer to compounds of formula I that can be separated into rotationally restricted isomers.
The compounds of this invention may contain olefin-like double bonds. When such bonds are present, the compounds of the invention exist as cis and trans configurations and as mixtures thereof.
A “suitable substituent” is intended to mean a chemically and pharmaceutically acceptable functional group i.e., a moiety that does not negate the inhibitory activity of the inventive compounds. Such suitable substituents may be routinely selected by those skilled in the art. Illustrative examples of suitable substituents include, but are not limited to halo groups, perfluoroalkyl groups, perfluoroalkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, hydroxy groups, oxo groups, mercapto groups, alkylthio groups, alkoxy groups, aryl or heteroaryl groups, aryloxy or heteroaryloxy groups, aralkyl or heteroaralkyl groups, aralkoxy or heteroaralkoxy groups, HO—(C═O)— groups, amino groups, alkyl- and dialkylamino groups, carbamoyl groups, alkylcarbonyl groups, alkoxycarbonyl groups, alkylaminocarbonyl groups dialkylamino carbonyl groups, arylcarbonyl groups, aryloxycarbonyl groups, alkylsulfonyl groups, arylsulfonyl groups and the like. Those skilled in the art will appreciate that many substituents can be substituted by additional substituents.
As used herein, the term “spiro” refers to a connection between two groups, substituents etc., wherein the connection can be depicted according to the following formula
As used herein, the term “alkyl,” as well as the alkyl moieties of other groups referred to herein (e.g., alkoxy), may be linear or branched (such as methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, secondary-butyl, tertiary-butyl); optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. The phrase “each of said alkyl” as used herein refers to any of the preceding alkyl moieties within a group such alkoxy, alkenyl or alkylamino. Preferred alkyls include (C 1 –C 4 )alkyl, most preferably methyl and ethyl.
As used herein, the term “cycloalkyl” refers to a mono, bicyclic or tricyclic carbocyclic ring (e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclopentenyl, cyclohexenyl, bicyclo[2.2.1]heptanyl, bicyclo[3.2.1]octanyl and bicyclo[5.2.0]nonanyl, etc.); optionally containing 1 or 2 double bonds and optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “halogen” includes fluoro, chloro, bromo or iodo or fluoride, chloride, bromide or iodide.
As used herein, the term “halo-substituted alkyl” refers to an alkyl radical as described above substituted with one or more halogens included, but not limited to, chloromethyl, dichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trichloroethyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “alkenyl” means straight or branched chain unsaturated radicals of 2 to 6 carbon atoms, including, but not limited to ethenyl, 1-propenyl, 2-propenyl (allyl), iso-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “(C 2 –C 6 )alkynyl” is used herein to mean straight or branched hydrocarbon chain radicals having one triple bond including, but not limited to, ethynyl, propynyl, butynyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “carbonyl” or “(C═O)” (as used in phrases such as alkylcarbonyl, alkyl-(C═O)— or alkoxycarbonyl) refers to the joinder of the >C═O moiety to a second moiety such as an alkyl or amino group (i.e. an amido group). Alkoxycarbonylamino (i.e. alkoxy (C═O)—NH—) refers to an alkyl carbamate group. The carbonyl group is also equivalently defined herein as (C═O). Alkylcarbonylamino refers to groups such as acetamide.
As used herein, the term “oxo” is used herein to mean a double bonded oxygen (═O) radical wherein the bond partner is a carbon atom. Such a radical can also be thought as a carbonyl group.
As used herein, the term “(C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—” is used herein to mean a radical of the formula
As used herein, the term “aryl” means aromatic radicals such as phenyl, naphthyl, tetrahydronaphthyl, indanyl and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl.
As used herein, the term “heteroaryl” refers to an aromatic heterocyclic group usually with one heteroatom selected from O, S and N in the ring. In addition to said heteroatom, the aromatic group may optionally have up to four N atoms in the ring. For example, heteroaryl group includes pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, thienyl, furyl, imidazolyl, pyrrolyl, oxazolyl (e.g., 1,3-oxazolyl, 1,2-oxazolyl), thiazolyl (e.g., 1,2-thiazolyl, 1,3-thiazolyl), pyrazolyl, tetrazolyl, triazolyl (e.g., 1,2,3-triazolyl, 1,2,4-triazolyl), oxadiazolyl (e.g., 1,2,3-oxadiazolyl), thiadiazolyl (e.g., 1,3,4-thiadiazolyl), quinolyl, isoquinolyl, benzothienyl, benzofuryl, indolyl, and the like; optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. Particularly preferred heteroaryl groups include oxazolyl, imidazolyl, pyridyl, thienyl, furyl, thiazolyl and pyrazolyl. Most preferred R 3 heteroaryls are thienyl and furyl.
The term “heterocyclic” as used herein refers to a cyclic group containing 1–9 carbon atoms and 1 to 4 hetero atoms selected from N, O, S(O) n or NR′. Examples of such rings include azetidinyl, tetrahydrofuranyl, imidazolidinyl, pyrrolidinyl, piperidinyl, piperazinyl, oxazolidinyl, thiazolidinyl, pyrazolidinyl, thiomorpholinyl, tetrahydrothiazinyl, tetrahydrothiadiazinyl, morpholinyl, oxetanyl, tetrahydrodiazinyl, oxazinyl, oxathiazinyl, indolinyl, isoindolinyl, quinuclidinyl, chromanyl, isochromanyl, benzoxazinyl, and the like. Examples of said monocyclic saturated or partially saturated ring systems are tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, imidazolidin-1-yl, imidazolidin-2-yl, imidazolidin-4-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, piperidin-1-yl, piperidin-2-yl, piperidin-3-yl, piperazin-1-yl, piperazin-2-yl, piperazin-3-yl, 1,3-oxazolidin-3-yl, isothiazolidine, 1,3-thiazolidin-3-yl, 1,2-pyrazolidin-2-yl, 1,3-pyrazolidin-1-yl, thiomorpholin-yl, 1,2-tetrahydrothiazin-2-y, 1,3-tetrahydrothiazin-3-yl, tetrahydrothiadiazin-yl, morpholin-yl, 1,2-tetrahydrodiazin-2-y, 1,3-tetrahydrodiazin-1-yl, 1,4-oxazin-2-yl, 1,2,5-oxathiazin-4-yl and the like; optionally containing 1 or 2 double bonds and optionally substituted by 1 to 3 suitable substituents as defined above such as fluoro, chloro, trifluoromethyl, (C 1 –C 6 )alkoxy, (C 6 –C 10 )aryloxy, trifluoromethoxy, difluoromethoxy or (C 1 –C 6 )alkyl. Preferred heterocyclics include tetrahydrofuranyl, pyrrolidinyl, piperidinyl, piperazinyl and morpholinyl. A group of R 1 heterocycles of particular interest are those heterocycles with 2 or more oxo substituents. Another group of R 1 heterocycles of particular interest are those heterocycles with three or more heteroatoms. Another group of R 1 heterocycles include 2-oxazepinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxopyridyl and 2-oxoquinolinyl. Preferred R 1 heterocycles include 6-azauracil, uracil, 2-oxo-piperidine, 2,3-dioxo-piperazine, 2-oxo-oxazole and 2-oxo-benzthiazine, most preferably 6-azauracil. Preferred R 3 heterocyclics include tetrahydrofuranyl, dioxanyl, tetrahydrothiophenyl, chromanyl, isochromanyl and sulfolanyl.
Nitrogen heteroatoms as used herein refers to N═, >N and —NH; wherein —N═ refers to a nitrogen double bond; >N refers to a nitrogen containing two bond connections and —N refers to a nitrogen containing one bond.
“Embodiment” as used herein refers to specific groupings of compounds or uses into discrete subgenera. Such subgenera may be cognizable according to one particular substituent such as a specific R 1 or R 3 group. Other subgenera are cognizable according to combinations of various substituents, such as all compounds wherein R 2 is chloro and R 3 is optionally substituted phenethyl. The phrase “in combination with each of the aforementioned embodiments” refers to combinations of the identified embodiment with each embodiment previously identified in the specification. Thus an embodiment of compounds wherein R 3 is optionally substituted phenethyl “in combination with each of the aforementioned embodiments” refers to additional embodiments comprising combinations of the R 3 is optionally substituted phenethyl embodiment with each embodiment previously identified in the specification.
A preferred embodiment of the invention is that group of phenyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═(CR 8 )— respectively, more preferably wherein each of R 6 , R 7 , and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═N—, ═(CR 7 )—, and ═(CR 8 )— respectively, more preferably wherein each of R 7 and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═N—, and ═(CR 8 )— respectively, more preferably wherein each of R 6 and R 8 is hydrogen.
Another embodiment of the invention is that group of pyridyl compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═(CR 7 )—, and ═N— respectively, more preferably wherein each of R 6 and R 7 is hydrogen.
Another embodiment of the invention is that group of pyridazine compounds of formula I wherein X, Y and Z are ═N—, ═(CR 7 )—, and ═N— respectively, more preferably wherein R 7 is hydrogen.
Another embodiment of the invention is that group of pyrimidine compounds of formula I wherein X, Y and Z are ═(CR 6 )—, ═N—, and ═N— respectively, more preferably wherein R 6 is hydrogen.
Another embodiment of the invention is that group of pyrazine compounds of formula I wherein X, Y and Z are ═N—, ═N—, and ═(CR 8 )— respectively, more preferably wherein R 8 is hydrogen.
Another more preferred embodiment of the invention is that group of amide compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds) wherein A is —(C═O)NH— and are known as the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups, respectively.
Another embodiment of the invention is that group of reverse amide compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds) wherein A is —NH(C═O)— and are known as the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups, respectively.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 4 –C 10 )alkyl, more preferably substituted with one to three substituents independently selected from hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl or wherein at least one of R 11 and R 12 is other than hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); more preferably wherein said substituents include one to three substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said substituents are independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted by at least one substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)-, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted by at least one spiro substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl spiro substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s —;
wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen);
wherein said (C 3 –C 12 )cycloalkyl of said (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — is substituted by one substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—; and
wherein said (C 3 –C 12 )cycloalkyl of said (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — is substituted by one or two substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said substituents are independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); more preferably wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by one to three substituents independently selected from the group consisting of hydrogen, halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, formyl, benzyloxy and (C 1 –C 4 )alkyl-(C═O)—; more preferably wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by one to three substituents independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, benzyloxy and (C 1 –C 4 )alkoxy.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); and wherein said (C 6 –C 10 )aryl of said (C 6 —C,O)aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by at least one substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); and wherein said (C 6 –C 10 )aryl of said (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )— group member is substituted by at least one spiro substituent (more preferably one substituent) selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid spiro substituent may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on any ring carbon atom able to support an additional substituent by one to three substituents per ring independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)— (more preferably wherein said substituents are independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, formyl, and (C 1 –C 4 )alkyl-(C═O)—).
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heteroaryl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on at least one ring carbon atom able to support an additional substituent by a substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O— substituent may optionally be substituted on any ring carbon atom by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on any ring carbon atom (more preferably one carbon atom) able to support an additional substituent by one to three substituents per ring independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)-(more preferably wherein said substituents are independently selected from the group consisting of halo, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, oxo, formyl, and (C 1 –C 4 )alkyl-(C═O)—).
Another embodiment of the invention is that group of compounds of formula I (and the phenyl, pyridyl, pyridazinyl, pyrimidyl, and pyrazinyl groups of compounds and the benzamide, nicotinamide, picolinamide, isonicotinamide, pyridazinamide, pyrimidinamide, and pyrazinamide groups of compounds and the formanilide, carboxaminopyridine, carboxaminopyridazine, carboxaminopyrimidine and carboxaminopyrazine groups of compounds) wherein R 3 is (C 1 –C 10 )heterocyclyl-(CR 11 R 12 ) s — (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen) optionally substituted on at least one ring carbon atom (more preferably one carbon atom) able to support an additional substituent by a substituent selected from the group consisting of (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O— substituent may optionally be substituted on any ring carbon atom by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another embodiment of the invention is that group of compounds wherein R 2 is chloro or bromo, more preferably wherein R 2 is chloro.
Another embodiment of the invention is that group of compounds wherein R 2 is (C 1 –C 4 )alkyl or —CN, more preferably wherein R 2 is methyl.
Another embodiment of the invention is that group of compounds wherein R 2 is hydroxy.
Another embodiment of the invention is that group of compounds wherein R 7 is other than hydrogen.
Another embodiment of the invention is that group of compounds of formula I wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
for simplicity, in the aforementioned examples of R 1 the substituents R 9 and R 10 have not been shown.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
for simplicity, in the aforementioned examples of R 1 the substituents R 9 and R 10 have not been shown.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 4 and R 5 are each independently selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl, or R 4 and R 5 may optionally be taken together with the nitrogen atom to which they are attached to form a 3 to 8 membered heterocycle.
Another embodiment of the invention is that group of compounds wherein R 1 is optionally substituted (C 1 –C 10 )heterocyclyl selected from the group consisting of
wherein R 9 is selected from the group consisting of hydrogen, —CF 3 , (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group;
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group.
Another embodiment of the invention is that group of compounds wherein R 9 is independently selected from the group of substituents selected from hydrogen, halo, —CN, and (C 1 –C 4 )alkyl optionally substituted with one to three fluoro; more preferably hydrogen or methyl.
Another embodiment of the invention is that group of compounds wherein R 9 is independently selected from the group of substituents selected from hydroxy, amino, (C 1 –C 4 )alkoxy optionally substituted with one to three fluoro, HO 2 C—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S—[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(O═C)—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N— and R 4 R 5 N(CH 2 ) t —.
Another embodiment of the invention is that group of compounds wherein each R 9 is independently selected from the group of substituents selected from (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—.
Another embodiment of the invention is that group of compounds wherein R 10 is independently selected from the group of substituents consisting of hydrogen and (C 1 –C 4 )alkyl optionally substituted with one to three fluoro; more preferably hydrogen or methyl.
Another embodiment of the invention is that group of compounds wherein each R 10 is independently selected from the group of substituents consisting of (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, wherein each of the aforesaid (C 6 –C 10 )aryl and (C 3 –C 8 )cycloalkyl, anywhere on said R 10 substituents may optionally be substituted by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—;
Another embodiment of the invention is that group of compounds wherein each R 10 is independently selected from the group of substituents consisting of (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 10 substituents may optionally be substituted by one to three suitable moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 —CH 2 —, CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
Another preferred embodiment of the invention is that group of compounds wherein R 1 is selected from the group
wherein R 9 is selected from the group consisting of hydrogen, —CF 3 , (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl or (C 3 –C 8 )cycloalkyl group.
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, CF 3 —CH 2 —, HO—(C 2 –C 6 )alkyl or (C 3 –C 8 )cycloalkyl group.
A preferred embodiment of the invention relates to compounds of formula I wherein R 1 is
wherein R 10 is selected from the group consisting of hydrogen, (C 1 –C 6 )alkyl, HO—(C 2 –C 6 )alkyl and (C 3 –C 8 )cycloalkyl group.
A more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is (C 4 –C 10 )alkyl; wherein said (C 4 –C 10 )alkyl may optionally be substituted by one to four substituents independently selected from chloro, fluoro, (C 6 –C 10 )aryl, (C 3 –C 6 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of said (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl or (C 1 –C 10 )heterocyclyl may optionally be substituted on any carbon atom able to support an additional moiety, by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said (C 3 –C 8 )cycloalkyl and (C 1 –C 10 )heterocyclyl substituents may also optionally be substituted by oxo; and
R 10 is hydrogen or (C 1 –C 4 )alkyl;
or a pharmaceutically acceptable salt or solvate thereof.
Another more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is (C 6 –C 10 )aryl-(CR 11 R 12 ) q —(CH 2 )—; wherein said (C 6 –C 10 )aryl may optionally be substituted by one to two substituents independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—.
or a pharmaceutically acceptable salt or solvate thereof.
Another more preferred embodiment of the invention relates to compounds of formula I wherein said compound of formula I has the formula
wherein R 3 is optionally substituted (C 3 –C 12 )cycloalkyl-(CR 11 R 12 ) s — wherein R 11 and R 12 are each independently hydrogen or (C 1 –C 4 )alkyl or wherein at least one of R 11 and R 12 is other than hydrogen or (C 1 –C 4 )alkyl (more preferably wherein each of R 11 and R 12 of the CR 11 R 12 directly attached to group A are hydrogen); halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, (C 1 –C 4 )alkyl-O—(C═O)—, formyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-S—.
Examples of specific preferred compounds of the formula I are the following:
2Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2,2-diphenyl-ethyl)-benzamide;
N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-benzamide;
N-[2-(2-Benzyloxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-benzamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-benzamide; and
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide.
Examples of other compounds of the formula I are the following:
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-butyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(4-phenyl-butyl)-benzamide;
2-Chloro-N-[2-(4-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-phenethyl-benzamide;
N-[2-(4-Bromo-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-fluoro-phenyl)-ethyl]-benzamide;
2-Chloro-N-[2-(2,6-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-methoxy-phenyl)-ethyl]-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-pentyl-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-ethoxy-phenyl)-ethyl]-benzamide;
N-[2-(5-Bromo-2-methoxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-octyl-benzamide;
2-Chloro-N-[2-(3-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-N-[2-(2,4-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-hexyl-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(4-fluoro-phenyl)-ethyl]-benzamide;
2-Chloro-N-cyclohexylmethyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-N-[2-(3,4-dichloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-phenyl-propyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-thiophen-2-yl-ethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-thiophen-2; -yl-ethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-methoxy-phenyl)-ethyl]-benzamide;
N-[2-(2-Bromo-4-methoxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-N-[2-(4-chloro-phenyl)-propyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cyclohexylmethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(5-hydroxy-1,3,3-trimethyl-cyclohexylmethyl)-benzamide;
N-Bicyclo[2.2.1]hept-2-ylmethyl-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-yl)-benzamide;
3-{[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoylamino]methyl}-cyclohexanecarboxylic acid methyl ester;
N-Bicyclo[2.2.1]hept-2-ylmethyl-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-d ioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-m-tolyl-ethyl)-benzamide;
2-Chloro-N-[2-(3-chloro-phenyl)-2-hydroxy-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-fluoro-phenyl)-2-hydroxy-ethyl]-benzamide;
3-{2-[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoylamino]-ethyl}-benzoic acid methyl ester;
2-Chloro-N-(6,6-dimethyl-bicyclo[3.1.1]hept-2-ylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-hydroxy-2-phenyl-ethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-isochroman-1-ylmethyl-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(3-methylsulfany-phenyl)-ethyl]-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-methoxy-2-phenyl-ethyl)-benzamide;
2-Chloro-N-(6,6-dimethyl-bicyclo[3.1.1]hept-2-ylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclopentylmethyl)-benzamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-methoxy-2-oxo-2H-pyridin-1-yl)-benzamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-ethyl-2,3-dioxo-piperazin-1-yl)-benzamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-oxazolidin-3-yl)-benzamide;
2-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-benzamide;
2-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide;
N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-methyl-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide;
N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-methyl-5-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-benzamide;
5-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-2-methyl-benzamide;
N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-methyl-benzamide;
N-[2-Chloro-5-(3-methyl-2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-phenyl]-3-(2-chloro-phenyl)-butyramide;
N-[2-Chloro-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-phenyl]-3-(2-chloro-phenyl)-3-methyl-butyramide;
2-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-benzamide;
2-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide;
N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-2-methyl-5-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-benzamide;
2-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-5-(3-oxo-2,3-dihydro-[1,4]thiazin-4-yl)-benzamide;
2-Chloro-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-benzamide;
2-Chloro-5-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-benzamide;
2-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-benzamide;
2-Chloro-N-(1-hydroxy-cycloheptylmethyl)-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide;
2-Chloro-N-cycloheptylmethyl-5-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide;
2-Chloro-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-benzamide;
2-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide;
2-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-benzamide;
N-[2-Chloro-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-phenyl]-3-[2-(1-hydroxy-1-methyl-ethyl)-phenyl]-propionamide; and
N-[2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-phenyl]-3-[2-(1-hydroxy-1-methyl-ethyl)-phenyl]-propionamide.
Examples of specific nicotinamides of the invention include:
2-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-nicotinamide;
2-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide;
N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-methyl-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide;
N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-methyl-5-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-nicotinamide;
5-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-2-methyl-nicotinamide;
N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-methyl-nicotinamide;
2-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-nicotinamide;
2-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide;
N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-2-methyl-5-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide;
2-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-5-(3-oxo-2,3-dihydro-[1,4]thiazin-4-yl)-nicotinamide;
2-Chloro-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-nicotinamide;
2-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-nicotinamide;
2-Chloro-N-(1-hydroxy-cycloheptylmethyl)-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide;
2-Chloro-N-cycloheptylmethyl-5-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide;
2-Chloro-5-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-nicotinamide;
2-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-nicotinamide;
2-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-5-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-nicotinamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl))-N-(2,2-diphenyl-ethyl)-nicotinamide;
N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-nicotinamide;
N-[2-(2-Benzyloxy-phenyl)-ethyl]-2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-nicotinamide;
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-nicotinamide;
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-nicotinamide; and
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-nicotinamide.
Examples of specific isonicotinamides of the invention include:
5-Chloro-N-[1-(4-chloro-phenyl)-4,4-difluoro-cyclohexylmethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-N-[3-(4-chloro-phenyl)-tetrahydro-pyran-3-ylmethyl]-2-[3,5-dioxo-4-(2,2,2-trifluoro-ethyl)-4,5-dihydro-3H-[1,2,4]triazin-2-yl]-isonicotinamide;
5-Chloro-N-[2-(4-fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-2-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide;
N-[2-(4-Fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-5-methyl-2-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide;
N-[2-(4-Fluoro-phenyl)-tetrahydro-pyran-2-ylmethyl]-5-methyl-2-[5-oxo-3-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-isonicotinamide;
2-(2,6-Dioxo-3,6-dihydro-2H-pyrimidin-1-yl)-N-[2-(4-fluoro-phenyl)-2-hydroxy-propyl]-5-methyl-isonicotinamide;
N-[2-(2-Chloro-phenyl)-2-hydroxy-propyl]-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-5-methyl-isonicotinamide;
5-Chloro-N-[2-(2-chloro-phenyl)-2-methyl-propyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]oxazin-4-yl)-isonicotinamide;
5-Chloro-N-[2-(2-chloro-thiophen-3-yl)-ethyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide;
N-[2-(3-Chloro-thiophen-2-yl)-ethyl]-5-methyl-2-(7-methyl-3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide;
5-Chloro-N-[2-(3-methyl-furan-2-yl)-ethyl]-2-(3-oxo-2,3-dihydro-[1,4]th iazin-4-yl)-isonicotinamide;
5-Chloro-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-N-(2-furan-2-yl-ethyl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-hydroxy-cycloheptylmethyl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-2,5-dihydro-3H-[1,2,4]triazin-4-yl)-N-(1-hydroxy-cycloheptylmethyl)-isonicotinamide;
5-Chloro-N-(4,4-difluoro-1-hydroxy-cyclohexylmethyl)-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-N-[4,4-difluoro-1-(5-methyl-thiophen-2-yl)-cyclohexylmethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(5-fluoro-thiophen-2-yl)-tetrahydro-pyran-2-ylmethyl]-isonicotinamide;
5-Chloro-N-(1-hydroxy-cycloheptylmethyl)-2-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide;
5-Chloro-N-cycloheptylmethyl-2-(5-oxo-3-trifluoromethyl-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide;
5-Chloro-2-(3-methyl-5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-N-[2-(4-trifluoromethyl-phenyl)-[1,3]dioxan-2-ylmethyl]-isonicotinamide;
5-Chloro-N-[2-(4-fluoro-phenyl)-[1,3]dioxan-2-ylmethyl]-2-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-isonicotinamide;
5-Chloro-N-[3-(4-fluoro-phenyl)-tetrahydro-pyran-3-ylmethyl]-2-[5-oxo-1-(2,2,2-trifluoro-ethyl)-1,5-dihydro-[1,2,4]triazol-4-yl]-isonicotinamide;
5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2,2-diphenyl-ethyl)-isonicotinamide;
N-[2-(2-Chloro-phenyl)-ethyl]-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-5-methyl-isonicotinamide;
N-[2-(2-Benzyloxy-phenyl)-ethyl]-5-chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-phenyl-cyclohexylmethyl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(1-p-tolyl-cyclohexylmethyl)-isonicotinamide;
5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-isonicotinamide;
5-Chloro-2-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-isonicotinamide; and
5-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-2-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-isonicotinamide.
Specific examples of other pyridine-2-carboxamides include:
3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide
3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (2,2-diphenyl-ethyl)-amide;
6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-3-methyl-pyridine-2-carboxylic acid [2-(2-Chloro-phenyl)-ethyl]-amide;
3-chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-Benzyloxy-phenyl)-ethyl]-amide;
3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (1-phenyl-cyclohexylmethyl)-amide;
3-Chloro-6-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid (1-p-tolyl-cyclohexylmethyl)-amide;
3-Chloro-6-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide;
3-Chloro-6-(3,5-d ioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-pyridine-2-carboxylic acid [2-(2-trifluoromethyl-phenyl)-ethyl]-amide; and
3-Chloro-6-(3-oxo-2,3-dihydro-benzo[1,4]thiazin-4-yl)-pyridine-2-carboxylic acid [2-(2-chloro-phenyl)-ethyl]-amide.
The present invention also includes isotopically-labelled compounds, which are identical to those recited in Formula I, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine, such as 2 H, 3 H, 13 C, 14 C, 15 N, 18 O, 17 O, 31 P, 32 P, 35 S, 18 F, and 36 Cl, respectively. Compounds of the present invention, prodrugs thereof, and pharmaceutically acceptable salts of said compounds or of said prodrugs which contain the aforementioned isotopes and/or other isotopes of other atoms are within the scope of this invention. Certain isotopically-labelled compounds of the present invention, for example those into which radioactive isotopes such as 3 H and 14 C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e., 3 H, and carbon-14, i.e., 14 C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium, i.e., 2 H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically-labelled compounds of Formula I of this invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the Schemes and/or in the Examples and Preparations below, by substituting a readily available isotopically-labelled reagent for a non-isotopically-labelled reagent.
The compounds of Formula I or a pharmaceutically acceptable salt thereof can be used in the manufacture of a medicament for the prophylactic or therapeutic treatment of any disease state in a human, or other mammal, which is exacerbated or caused by excessive or unregulated cytokine production by such mammal's cells, such as but not limited to monocytes and/or macrophages.
The present invention relates to a method for treating a P2X 7 mediated disease in a mammal in need thereof, which comprises administering to said mammal an effective amount of a compound of formula I.
The present invention also relates to a method for treating a condition selected from the group consisting of arthritis (including psoriatic arthritis, Reiter's syndrome, rheumatoid arthritis, gout, traumatic arthritis, rubella arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and acute synovitis), inflammatory bowel disease, Crohn's disease, emphysema, acute respiratory distress syndrome, adult respiratory distress syndrome, asthma, bronchitis chronic obstructive pulmonary disease, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoidosis, allergic reactions, allergic contact hypersensitivity, eczema, contact dermatitis, psoriasis, sunburn, cancer, tissue ulceration, restenosis, periodontal disease, epidermolysis bullosa, osteoporosis, bone resorption disease, loosening of artificial joint implants, atherosclerosis, aortic aneurysm, congestive heart failure, myocardial infarction, stroke, cerebral ischemia, head trauma, neurotrauma, spinal cord injury, neuro-degenerative disorders, Alzheimer's disease, Parkinson's disease, migraine, depression, peripheral neuropathy, pain, cerebral amyloid angiopathy, nootropic or cognition enhancement, amyotrophic lateral sclerosis, multiple sclerosis, ocular angiogenesis, corneal injury, macular degeneration, corneal scarring, scleritis, abnormal wound healing, burns, autoimmune disorders, Huntington's disease, diabetes, AIDS, cachexia, sepsis, septic shock, endotoxic shock, conjunctivitis shock, gram negative sepsis, toxic shock syndrome, cerebral malaria, cardiac and renal reperfusion injury, thrombosis, glomerularonephritis, graft vs. host reaction, allograft rejection, organ transplant toxicity, ulcerative colitis, or muscle degeneration, in a mammal, including a human, comprising administering to said mammal an amount of a compound to formula I, effective in treating such a condition.
The present invention relates to a pharmaceutical composition for the treatment of a P2X 7 mediated disease in a mammal which comprises an effective amount of a compound according to formula I and a pharmaceutically acceptable carrier.
The present invention relates to a pharmaceutical composition for the treatment of a condition selected from the group consisting of arthritis (including psoriatic arthritis, Reiter's syndrome, rheumatoid arthritis, gout, traumatic arthritis, rubella arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and acute synovitis), inflammatory bowel disease, Crohn's disease, emphysema, acute respiratory distress syndrome, adult respiratory distress syndrome, asthma, bronchitis, chronic obstructive pulmonary disease, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoidosis, allergic reactions, allergic contact hypersensitivity, eczema, contact dermatitis, psoriasis, sunburn, cancer, tissue ulceration, restenosis, periodontal disease, epidermolysis bullosa, osteoporosis, bone resorption disease, loosening of artificial joint implants, atherosclerosis, aortic aneurysm, congestive heart failure, myocardial infarction, stroke, cerebral ischemia, head trauma, neurotrauma, spinal cord injury, neuro-degenerative disorders, Alzheimer's disease, Parkinson's disease, migraine, depression, peripheral neuropathy, pain, cerebral amyloid angiopathy, nootropic or cognition enhancement, amyotrophic lateral sclerosis, multiple sclerosis, ocular angiogenesis, corneal injury, macular degeneration, corneal scarring, scleritis, abnormal wound healing, burns, autoimmune disorders, Huntington's disease, diabetes, AIDS, cachexia, sepsis, septic shock, endotoxic shock, conjunctivitis shock, gram negative sepsis, toxic shock syndrome, cerebral malaria, cardiac and renal reperfusion injury, thrombosis, glomerularonephritis, graft vs. host reaction, allograft rejection, organ transplant toxicity, ulcerative colitis, or muscle degeneration in a mammal, including a human, comprising an amount of a compound to formula I, effective in treating such a condition and a pharmaceutically acceptable carrier.
Preferably, the compounds of the invention are useful for the treatment of rheumatoid arthritis, osteoarthritis, psoriasis, allergic dermatitis, asthma, chronic obstructive pulmonary disease (COPD), hyperresponsiveness of the airway, septic shock, glomerulonephritis, irritable bowel disease, Crohn's disease, ulcerative colitis, atherosclerosis, growth and metastases of malignant cells, myoblastic leukemia, diabetes, Alzheimer's disease, meningitis, osteoporosis, burn injury, ischemic heart disease, stroke and varicose veins.
The present invention also provides a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined for use in therapy.
In another aspect, the invention provides the use of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined in the manufacture of a medicament for use in therapy.
The invention further provides a method of treating osteoarthritis which comprises administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The invention further provides a method of effecting immunosuppression (e.g. in the treatment of rheumatoid arthritis, irritable bowel disease, atherosclerosis or psoriasis) which comprises administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The invention also provides a method of treating an obstructive airways disease (e.g. asthma or COPD) which comprises administering to a patient a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined to a patient.
The term “treating”, as used herein, refers to reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition. The term “treatment”, as used herein, refers to the act of treating, as “treating” is defined immediately above.
The present invention also provides a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined in association with a pharmaceutically acceptable adjuvant, diluent or carrier.
The invention further provides a process for the preparation of a pharmaceutical composition of the invention which comprises mixing a compound of formula (I), or a pharmaceutically acceptable salt or solvate thereof, as hereinbefore defined with a pharmaceutically acceptable adjuvant, diluent or carrier.
For the above-mentioned therapeutic uses the dosage administered will, of course, vary with the compound employed, the mode of administration, the treatment desired and the disorder indicated. The daily dosage of the compound of formula (I)/salt/solvate (active ingredient) may be in the range from 1 mg to 1 gram, preferably 1 mg to 250 mg, more preferably 10 mg to 100 mg.
The present invention also encompasses sustained release compositions.
The present invention also relates to processes of preparing the compounds of formula I and intermediates used in such processes.
One embodiment of the processes of the invention relates to the preparation of compounds of formula
wherein A, X, Y, Z, R 1 , R 2 and R 3 are as described above (including all embodiments and preferences of formula I described above); comprising reacting:
a) a compound of formula
wherein X, Y, Z, R 1 and R 2 are as defined above; L is halo or anhydro, with a compound of the formula.
H 2 N—R 3 III
wherein R 3 is as defined above; and a base; or
b) a compound of the formula
wherein X, Y, Z, R 1 and R 2 are as described above; with a compound of formula
H 2 N—R 3 III
wherein R 3 is as defined above; in the presence of a coupling reagent, a base and a solvent; or
c) a compound of the formula
wherein X, Y, Z, R 1 and R 2 are as defined above; with a compound of the formula
wherein L 1 is a leaving group selected from the group consisting of chloro, fluoro, bromo, iodo or anhydro, and a base and a solvent.
Another embodiment of the present invention are intermediates of the formula
wherein X, Y, Z, R 1 , R 2 and L are described as above (including all embodiments and preferences for X, Y, Z, R 1 and R 2 described above).
Another embodiment of the present invention are intermediates of the formula
wherein X, Y, Z, R 1 and R 2 are as described above (including all embodiments and preferences for X, Y, Z, R 1 and R 2 described above).
One of ordinary skill in the art will appreciate that the compounds of the invention are useful in treating a diverse array of diseases. One of ordinary skill in the art will also appreciate that when using the compounds of the invention in the treatment of a specific disease that the compounds of the invention may be combined with various existing therapeutic agents used for that disease.
For the treatment of rheumatoid arthritis, the compounds of the invention may be combined with agents such as TNF-α inhibitors such as anti-TNF monoclonal antibodies (such as Remicade, CDP-870 and D 2 E 7 ) and TNF receptor immunoglobulin molecules (such as Enbrel®), COX-2 inhibitors (such as meloxicam, celecoxib, rofecoxib, valdecoxib and etoricoxib) low dose methotrexate, lefunomide; ciclesonide; hydroxychloroquine, d-penicillamine, auranofin or parenteral or oral gold.
The present invention still further relates to the combination of a compound of the invention together with a leukotriene biosynthesis inhibitor, 5-lipoxygenase (5-LO) inhibitor or 5-lipoxygenase activating protein (FLAP) antagonist selected from the group consisting of zileuton; ABT-761; fenleuton; tepoxalin; Abbott-79175; Abbott-85761; N-(5-substituted)-thiophene-2-alkylsulfonamides; 2,6-di-tert-butylphenol hydrazones; methoxytetrahydropyrans such as Zeneca ZD-2138; the compound SB-210661; pyridinyl-substituted 2-cyanonaphthalene compounds such as L-739,010; 2-cyanoquinoline compounds such as L-746,530; indole and quinoline compounds such as MK-591, MK-886, and BAY×1005.
The present invention still further relates to the combination of a compound of the invention together with a receptor antagonists for leukotrienes LTB 4 , LTC 4 , LTD 4 , and LTE 4 selected from the group consisting of the phenothiazin-3-ones such as L-651,392; amidino compounds such as CGS-25019c; benzoxalamines such as ontazolast; benzenecarboximidamides such as BIIL 284/260; and compounds such as zafirlukast, ablukast, montelukast, pranlukast, verlukast (MK-679), RG-12525, Ro-245913, iralukast (CGP 45715A), and BAY×7195.
The present invention still further relates to the combination of a compound of the invention together with a PDE4 inhibitor including inhibitors of the isoform PDE4D.
The present invention still further relates to the combination of a compound of the invention together with a antihistaminic H 1 receptor antagonists including cetirizine, loratadine, desloratadine, fexofenadine, astemizole, azelastine, and chlorpheniramine.
The present invention still further relates to the combination of a compound of the invention together with a gastroprotective H 2 receptor antagonist.
The present invention still further relates to the combination of a compound of the invention together with an α 1 - and α 2 -adrenoceptor agonist vasoconstrictor sympathomimetic agent, including propylhexedrine, phenylephrine, phenylpropanolamine, pseudoephedrine, naphazoline hydrochloride, oxymetazoline hydrochloride, tetrahydrozoline hydrochloride, xylometazoline hydrochloride, and ethylnorepinephrine hydrochloride.
The present invention still further relates to the combination of a compound of the invention together with anticholinergic agents including ipratropium bromide; tiotropium bromide; oxitropium bromide; pirenzepine; and telenzepine.
The present invention still further relates to the combination of a compound of the invention together with a β 1 - to β 4 -adrenoceptor agonists including metaproterenol, isoproterenol, isoprenaline, albuterol, salbutamol, formoterol, salmeterol, terbutaline, orciprenaline, bitolterol mesylate, and pirbuterol; or methylxanthanines including theophylline and aminophylline; sodium cromoglycate; or muscarinic receptor (M1, M2, and M3) antagonist.
The present invention still further relates to the combination of a compound of the invention together with an insulin-like growth factor type I (IGF-1) mimetic.
The present invention still further relates to the combination of a compound of the invention together with an inhaled glucocorticoid with reduced systemic side effects, including prednisone, prednisolone, flunisolide, triamcinolone acetonide, beclomethasone dipropionate, budesonide, fluticasone propionate, and mometasone furoate.
The present invention still further relates to the combination of a compound of the invention together with (a) tryptase inhibitors; (b) platelet activating factor (PAF) antagonists; (c) interleukin converting enzyme (ICE) inhibitors; (d) IMPDH inhibitors; (e) adhesion molecule inhibitors including VLA-4 antagonists; (f) cathepsins; (g) MAP kinase inhibitors; (h) glucose-6 phosphate dehydrogenase inhibitors; (i) kinin-B 1 - and B 2 -receptor antagonists; (j) anti-gout agents, e.g., colchicine; (k) xanthine oxidase inhibitors, e.g., allopurinol; (I) uricosuric agents, e.g., probenecid, sulfinpyrazone, and benzbromarone; (m) growth hormone secretagogues; (n) transforming growth factor (TGFβ); (o) platelet-derived growth factor (PDGF); (p) fibroblast growth factor, e.g., basic fibroblast growth factor (bFGF); (q) granulocyte macrophage colony stimulating factor (GM-CSF); (r) capsaicin cream; (s) Tachykinin NK 1 and NK 3 receptor antagonists selected from the group consisting of NKP-608C; SB-233412 (talnetant); and D-4418; and (t) elastase inhibitors selected from the group consisting of UT-77 and ZD-0892.
The present invention still further relates to the combination of a compound of the invention together with an inhibitor of matrix metalloproteases (MMPs), i.e., the stromelysins, the collagenases, and the gelatinases, as well as aggrecanase; especially collagenase-1 (MMP-1), collagenase-2 (MMP-8), collagenase-3 (MMP-13), stromelysin-1 (MMP-3), stromelysin-2 (MMP-10), and stromelysin-3 (MMP-11).
The compounds of the invention can also be used in combination with existing therapeutic agents for the treatment of osteoarthritis. Suitable agents to be used in combination include standard non-steroidal anti-inflammatory agents (hereinafter NSAID's) such as piroxicam, diclofenac, propionic acids such as naproxen, flubiprofen, fenoprofen, ketoprofen and ibuprofen, fenamates such as mefenamic acid, indomethacin, sulindac, apazone, pyrazolones such as phenylbutazone, salicylates such as aspirin, COX-2 inhibitors such as celecoxib, valdecoxib, rofecoxib and etoricoxib, analgesics and intraarticular therapies such as corticosteroids and hyaluronic acids such as hyalgan and synvisc.
The compounds of the present invention may also be used in combination with anticancer agents such as endostatin and angiostatin or cytotoxic drugs such as adriamycin, daunomycin, cis-platinum, etoposide, taxol, taxotere and farnesyl transferase inhibitors, VegF inhibitors, COX-2 inhibitors and antimetabolites such as methotrexate antineoplastic agents, especially antimitotic drugs including the vinca alkaloids such as vinblastine and vincristine;.
The compounds of the invention may also be used in combination with antiviral agents such as Viracept, AZT, aciclovir and famciclovir, and antisepsis compounds such as Valant.
The compounds of the present invention may also be used in combination with cardiovascular agents such as calcium channel blockers, lipid lowering agents such as statins, fibrates, beta-blockers, Ace inhibitors, Angiotensin-2 receptor antagonists and platelet aggregation inhibitors.
The compounds of the present invention may also be used in combination with CNS agents such as antidepressants (such as sertraline), anti-Parkinsonian drugs (such as deprenyl, L-dopa, Requip, Mirapex, MAOB inhibitors such as selegine and rasagiline, comP inhibitors such as Tasmar, A-2 inhibitors, dopamine reuptake inhibitors, NMDA antagonists, Nicotine agonists, Dopamine agonists and inhibitors of neuronal nitric oxide synthase), and anti-Alzheimer's drugs such as donepezil, tacrine, COX-2 inhibitors, propentofylline or metryfonate.
The compounds of the present invention may also be used in combination with osteoporosis agents such as roloxifene, droloxifene, lasofoxifene or fosomax and immunosuppressant agents such as FK-506, rapamycin, cyclosporine, azathioprine, and methotrexate;.
DETAILED DESCRIPTION OF THE INVENTION
Compounds of the formula I may be prepared according to the following reaction schemes and discussion. Unless otherwise indicated A, X, Y, Z, n, q, s, t, and R 1 through R 12 and structural formula I in the reaction schemes and discussion that follow are as defined above.
Scheme 1 refers to the preparation of compounds of formula I. Compounds of formula I, wherein A is —(C═O)—NH—, can be prepared from compounds of formula II, wherein L is a halo or an anhydride leaving group of the formula R—(C═O)—O— wherein R is optionally substituted alkyl or aryl, by reaction with a compound of formula III
in the presence of a base. Suitable bases include an excess of compound of formula III as well as triethylamine, dimethylaminopyridine, sodium carbonate, pyridine, and Hunigs base, preferably triethylamine. The aforesaid reaction may be performed neat or in the presence of a solvent. Suitable solvents include methylene chloride, tetrahydrofuran, and toluene, preferably methylene chloride.
Alternatively, compounds of formula I, wherein A is —C═ONH—, can be prepared from compounds of formula IV, by reaction with a compound of formula III in the presence of a coupling reagent, such as 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide (EDC) or dicyclohexyl carbodiimide (DCC) and hydroxybenzotriazole hydrate (HOBt), and a base, such as diisopropylethylamine (DIEA) or triethylamine, in an aprotic solvent, such as methylene chloride. Suitable solvents include methylene chloride and dimethyl formamide, preferably methylene chloride. The aforesaid reaction may be run at a temperature from about 0° C. to about 50° C., for a period from about 1 hour to about 16 hours (as illustrated in Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc. (1989) pp. 972–976).
Compounds of formula I, wherein A is —NH—(C═O)—, may be prepared from compounds of formula V by reaction with a compound of the formula VI
wherein L′ is a leaving group such as chloro, fluoro, bromo, iodo or an anhydride leaving group of the formula R—(C═O)—O—, wherein R is optionally substituted alkyl or aryl. The aforesaid reaction may be conducted in the presence of a suitable base. Suitable bases include an excess of compound of formula V as well as triethylamine, dimethylaminopyridine, sodium carbonate, pyridine, and HOnigs base, preferably triethylamine. The aforesaid reaction may be performed neat or in the presence of a solvent at a temperature from about 0° C. to about 50° C., for a period from about 10 minutes to about 16 hours. Suitable solvents include methylene chloride, tetrahydrofuran, and toluene, preferably methylene chloride.
Compounds of formula II and IV can be made according to the methods of Scheme 2.
Compounds of formula V can be made according to the methods of Scheme 3.
Scheme 2 refers to the preparation of compounds of formulae IV and II, wherein L is a leaving group and R 1 is nitrogen linked (C 1 –C 10 )heterocyclyl. Compounds of formulae II and IV can be converted into compounds of formula I according to the methods of Scheme 1.
Referring to Scheme 2, a compound of the formula IV can be prepared from a compound of the formula II, wherein L is a leaving group such as a methyl or ethyl ester, by reaction with a saponification reagent such as with an aqueous base, such as sodium hydroxide in an alcoholic solvent such as methanol, ethanol or tert.-butanol. The aforesaid reaction may be run at a temperature from about 0° C. to about 100° C., for a period from about 1 hour to about 24 hours. When L is a leaving group such as tert.-butyl ester, a compound of the formula IV can be prepared by the reaction of a compound of formula II with an acid such as hydrochloric acid in a solvent such as dioxane at a temperature between 25° C. to about 80° C., for a period from about 10 minutes to about 6 hours.
A compound of the formula II, wherein L is a leaving group such as alkoxy, and R 1 is nitrogen linked (C 1 –C 10 )heterocyclyl, can be prepared from a compound of the formula VI by reaction with a compound of the formula
wherein d is 1 to 8 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond; W is >C═O or >SO 2 ; and each L 2 is independently hydrogen, (C 1 –C 6 )alkyl or halo; under reductive amination conditions. The reductive amination is typically carried out with a reducing agent, such as sodium cyanoborohydride or sodium triacetoxyborohydride, preferably at a pH of between 6 and 8. The reaction is normally performed in a protic solvent, such as methanol or ethanol, or in a mixture of solvents, such as dichloroethane/methanol, at temperature of about −78° C. to about 40° C. for a period from about 1 hour to about 24 hours. (See A. Abdel-Magid, C. Maryanoff, K. Carson, Tetrahedron Lett ., Vol. 34, Issue 31, 5595–98, 1990). Other conditions involve the use of titanium isopropoxide and sodium cyanoborohydride (R. J. Mattson et al., J. Org. Chem. 1990, 55, 2552–4) or involve the formation of the imine under dehydrating conditions followed by reduction ( Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc (1989) pp. 421–425).
Alternatively, a compound of the formula II, wherein L is a leaving group such as alkoxy, and R 1 is (C 1 –C 10 )heterocyclyl wherein the bridgehead atom is nitrogen, can be prepared from the diazonium intermediate derived from a compound of the formula VII. The diazonium intermediate is prepared by reaction of a compound of the formula VII with an acid such as hydrochloric acid followed by treatment with sodium nitrite in a solvent such as glacial acetic acid at a temperature from about 0° C. to about 30° C., and the reaction is generally run for a period of about 30 min to about 3 hours. The compound of the formula II is prepared by the reaction of the above diazonium intermediate with a compound of the formula VIII wherein d is 1 to 8 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with either an oxo group or a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond; W is >C═O or >SO 2 ; and each L 2 is independently alkoxy or halo; under basic conditions. The reaction is typically carried out with sodium acetate as base at a temperature from about 0° C. to about 120° C., and the reaction is generally run for a period of about 1 hour to about 24 hours. (For example, see R. D. Carroll et al., J. Med. Chem. 1983, 26, 96–100).
Alternatively, one skilled in the art will also appreciate that a compound of formula II wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocycle, can be prepared by standard synthetic methods from a compound of the formula VII, wherein L is a protecting group such as alkoxy, by reaction with a bidentate reagent wherein two different transformable groups exist, such as an alkylating and acylating group of the formula
wherein L is a leaving group such as halo, L 2 is hydrogen, (C 1 –C 6 )alkyl, hydroxy, (C 1 –C 6 )alkoxy or halo; W is >C═O or >SO 2 ; d is 1 to 9 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond.
Alternatively, one skilled in the art will also appreciate that a compound of formula II wherein R 1 is an nitrogen linked (C 1 –C 10 )heterocycle, can be prepared by standard synthetic methods from a compound of the formula VII, wherein L is a protecting group such as alkoxy, by reaction with an anhydride reagent of the formula
wherein d is 1 to 9 and wherein any of said —CH 2 — groups may be optionally substituted by one or two R 9 substituents, and wherein any of said —CH 2 — groups may optionally be replaced with a heteroatom selected from —O—, —S(O) n —, or —NR 10 — wherein n is an integer from zero to 2; or any single bond between any two CH 2 groups may optionally be a double bond.
Compounds of the formula VII can be prepared from compounds of the formula XI by reaction with an alcohol of the formula ROH, wherein R is optionally substituted (C 1 –C 4 )alkyl or (C 6 –C 10 )aryl, in the presence of an acid (a so called Fischer esterification) or a coupling reagent, such as 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide (EDC) or dicyclohexyl carbodiimide (DCC) and hydroxybenzotriazole hydrate (HOBt), and a base, such as diisopropylethylamine (DIEA) or triethylamine, in an aprotic solvent, such as methylene chloride. Suitable solvents include methylene chloride and dimethyl formamide, preferably methylene chloride. The aforesaid reaction may be run at a temperature from about 0° C. to about 50° C., for a period from about 1 hour to about 16 hours (as illustrated in Comprehensive Organic Transformation , R. C. Larock, VCH Publisher, Inc. (1989) pp. 972–976).
Compounds of the formulae VII, IX, X and XI are commercially available or can be made by methods well known to those of ordinary skill in the art.
Scheme 3 refers to the preparation of the compounds of formula V which are intermediates useful in the preparation of compound of formula I, in Scheme 1. Referring to Scheme 3, a compound of formula V is prepared by reduction of a compound of the formula XII. Reduction may be effected with hydrogen gas (H 2 ), using catalysts such as palladium on carbon (Pd/C), palladium on barium sulfate (Pd/BaSO 4 ), platinum on carbon (Pt/C), or tris(triphenylphosphine) rhodium chloride (Wilkinson's catalyst), in an appropriate solvent such as methanol, ethanol, THF, dioxane or ethyl acetate, at a pressure from about 1 to about 5 atmospheres and a temperature from about 10° C. to about 60° C., as described in Catalytic HVdrogenation in Organic Synthesis , Paul Rylander, Academic Press Inc., San Diego, 31–63 (1979). The following conditions are preferred: Pd on carbon, methanol at 25° C. and 50 psi of hydrogen gas pressure.
An alternative procedure employing the use of reagents such as ammonium formate and Pd/C in methanol at the reflux temperature under an inert atmosphere (e.g., nitrogen or argon gas) is also effective.
Another alternative reduction procedure, for use when R 1 contains a group incompatible with the above hydrogenation conditions (e.g., an olefin or halide group), is a dissolving metal reduction wherein the compound of formula XII is treated with a metal, such as zinc, tin or iron, in the presence of an acid such as hydrochloric or sulfuric acid. The aforesaid reaction may be run at a temperature from about 0° C. to about 100° C., for a period from about 1 hour to about 16 hours.
Compounds of the formula XII can be prepared from compounds of formula XIII by reaction with reagents of the formulae VII, IX and X as described previously in Scheme 2 for the conversion of a compound of formula VII to II.
The starting materials of the formula XIII are either commercially available or known in the art.
Scheme 4 refers to alternate preparations of compounds of formula I.
Referring to Scheme 4, compounds of the formula I, wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl, can be prepared by an aryl palladium coupling reaction. Aryl palladium coupling reactions are well known to those skilled in the art. One well known coupling method, so called Buchwald and Hartwig conditions, involves the coupling of a compound of formula XIV, wherein L 2 is Cl, Br, I or triflate (TfO), with a compound of the formula R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, in the presence of a palladium (0) catalyst and a base. Palladium (0) catalysts include tris(dibenzylidene acetone)dipalladium (O) (Pd 2 (dba) 3 ), di(dibenzylidene acetone)palladium(O) (Pd(dba) 2 ), palladium acetate (Pd(OAc) 2 , and a suitable ligand, such as a triaryl phosphine ligand, tri(t-butyl)phosphine, 1,1′-bis(diphenylphosphanyl)ferrocene (DPPF), 2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyl (BINAP), or PHANEPHOS, preferably tri(ortho-tolyl)phosphine. Suitable bases include K 2 CO 3 , K 2 PO 4 , CsCO 3 , LiN(TMS) 2 or an alkoxide base such as sodium methoxide, sodium ethoxide, potassium t-butoxide, preferably sodium tert-butoxide. Suitable solvents include toluene or an ethereal solvent, preferably dioxane. The aforesaid reaction may be run at a temperature of about 40° C. to 110° C. for about 1 to 48 hours. Such conditions are reviewed in Angew. Chem. Int. Ed. Engl. 1998, 37, 2046–2067 and are well known to those of ordinary skill in the art. Preferred Buchwald conditions use palladium acetate (Pd(OAc) 2 ) or palladium tetra-triphenylphosphine (Pd(PPh 3 ) 4 ) as the source of the palladium. Suitable solvents include THF, toluene or ethereal solvents. The aforesaid reaction may be run at a temperature of about 25° C. to 110° C. for about 1 to 4 hours, preferably 2 hours. Nickel catalysts, such as Ni(cod) (nickel 1,5-cyclooctadiene), are also well known.
Alternatively, compounds of formula I, can be prepared according to a so called Ullmann reaction by reaction of a compound of the formula XIV, wherein L 2 is a halide, with a compound of the formula R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, in the presence of a suitable base and a suitable catalyst. Suitable bases include alkali metal carbonates or hydroxide bases, preferably potassium carbonate. Suitable catalysts include copper (0) catalyst, preferably finely powdered copper bronze. Suitable solvents for the aforesaid reaction include neat or polar aprotic solvents, such as dimethylformamide (DMF), N,N dimethylacetamide or N-methylpyrrolidinone (NMP). The aforesaid reaction may be run at a temperature between about 80° C. and 180° C. for about 6 to 24 hours.
Alternatively, coupling can be carried out by a so called Suzuki coupling reaction of said compound of formula XIV, wherein L 2 is borate or boronic acid, with an R 1 —H, wherein H is a hydrogen on a nitrogen ring atom, a catalyst, a base and a dehydrating agent. Suitable borates include (HO) 2 B—, 9-BBN, and alkylboranes. Suitable catalysts include copper or palladium (such as palladium acetate (Pd(OAc) 2 ), palladium triphenylphosphine or Pd(dppf)Cl 2 ), preferably copper (II) acetate. Suitable dehydrating agents include 4 angstrom molecular sieves. Suitable bases include tertiary amine bases, such as triethylamine or pyridine, Na 2 CO 3 , sodium ethoxide, and K 3 PO 4 . Suitable solvents include methylene chloride, dimethyl sulfoxide (DMSO) or tetrahydrofuran (THF). The aforesaid reaction is typically performed under an atmosphere of oxygen gas at a temperature of about 10° C. to 50° C., preferably about 23° C. for about 6 to 72 hours. Palladium-catalyzed boronic acid couplings are described in Miyaura, N., Yanagi, T., Suzuki, A. Syn. Comm. 1981, 11, 7, p. 513.
Alternatively, compounds of formula I can also be prepared from compounds of formula XV or XVI via intermediates of the formula II and XII. The intermediates of the formula II and XII can be converted to compounds of formula I according to the methods of Schemes 1 and 3 respectively. The compounds of formulae II and XII can be prepared from compounds of the formulae XV and XVI, respectively, by coupling reactions analogous to those described above for the conversion of compounds of formula XIV to formula I.
Compounds of formula XIV can be prepared from compounds of formula XV or XVI by methods analogous to the conversion of compounds of formula II to I and XII to I.
Compounds of the formula XV and XVI are commercially available or can be made by methods well known to those skilled in the art.
Scheme 5 refers to an alternate preparation of compounds of formula I. Referring to Scheme 5, a compound of formula I is prepared from a compound of formula XVII by reduction with tin in the presence of an acid such as hydrochloric acid followed by a so called Sandmeyer reaction wherein a diazonium intermediate is prepared by treatment with sodium nitrite followed by cuprous halide quench such as cuprous chloride or cuprous bromide. Suitable solvents include alcohols such as methanol and ethanol. The aforesaid reaction is conducted at a temperature from about −20° C. to about 0° C., and the reaction is generally run for a period of about 1 to 48 hours.
The compound of formula XVII, wherein R 1 is a standard transformable group, such a —NH 2 , or a heterocycle can be prepared from a compound of the formula XVIII by reaction with a nucleophile according to standard chemical methods well known to those skilled in the art. Methods for nucleophilic aromatic substitution are reviewed in Belfield et al., Tetrahedron, 55, 11399–11428 (1999) and in March, Advanced Organic Chemistry, 641–676 (John Wiley & Sons, Inc., Fourth Edition, 1992).
Other compounds of formula XVII, wherein R 1 is a nitrogen linked (C 1 –C 10 )heterocyclyl containing one to six heteroatoms independently selected from —N═, —N<, —NH—, —O— and —S(O) n —; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl is substituted by at least one oxo substituent; wherein said nitrogen linked (C 1 –C 10 )heterocyclyl may also optionally be substituted on any carbon atom able to support an additional substituent, by one to three R 9 substituents per ring, each R 9 is independently selected from the group consisting of hydrogen, halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, HO 2 C—, R 4 R 5 N(O 2 S)—, (C 1 –C 4 )alkyl-(O 2 S)—NH—, (C 1 –C 4 )alkyl-O 2 S-[(C 1 –C 4 )alkyl-N]—, R 4 R 5 N(O═C)—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, R 4 R 5 N(CH 2 ) t —, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl, (C 1 –C 10 )heterocyclyl, (C 6 –C 10 )aryl-O—, (C 3 –C 8 )cycloalkyl-O—, (C 1 –C 10 )heteroaryl-O— and (C 1 –C 10 )heterocyclyl-O—; wherein said (C 1 –C 10 )heterocyclyl may also optionally be substituted on any ring nitrogen atom able to support an additional substituent by one to two R 10 substituents per ring, each R 10 is independently selected from the group consisting of hydrogen, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkyl-(C═O)—, (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl; wherein each of the aforesaid (C 6 –C 10 )aryl, (C 3 –C 8 )cycloalkyl, (C 1 –C 10 )heteroaryl and (C 1 –C 10 )heterocyclyl anywhere on said R 9 and R 10 group members or substituents may optionally be substituted by one to three moieties per ring, independently selected from the group consisting of halo, hydroxy, amino, —CN, (C 1 –C 4 )alkyl, (C 1 –C 4 )alkoxy, —CF 3 , CF 3 O—, (C 1 –C 4 )alkyl-NH—, [(C 1 –C 4 )alkyl] 2 -N—, (C 1 –C 4 )alkyl-S—, (C 1 –C 4 )alkyl-(S═O)—, (C 1 –C 4 )alkyl-(SO 2 )—, —(C 1 –C 4 )alkyl-O—(C═O)—, formyl, and (C 1 –C 4 )alkyl-(C═O)—; can be prepared by standard conversion methods from compounds of formula XVII, wherein R 1 is a standard transformable group.
Compounds of formula XVIII are commercially available or can be made by methods known to those skilled in the art.
Alternatively, compounds of formula I and II can be prepared from compounds of formula XX by analogous Sandmeyer methods as described above.
Compounds of formula XX can be prepared from compounds of formula XXI by methods analogous to the conversion of compounds of formula XVIII to XVII described above.
Compounds of formula XXI are commercially available or can be made by methods well known to those skilled in the art.
The compounds of the formula I which are basic in nature are capable of forming a wide variety of different salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to initially isolate a compound of the formula I from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert the latter back to the free base compound by treatment with an alkaline reagent, and subsequently convert the free base to a pharmaceutically acceptable acid addition salt. The acid addition salts of the base compounds of this invention are readily prepared by treating the base compound with a substantially equivalent amount of the chosen mineral or organic acid in an aqueous solvent medium or in a suitable organic solvent such as methanol or ethanol. Upon careful evaporation of the solvent, the desired solid salt is obtained.
The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as chloride, bromide, iodide, nitrate, sulfate or bisulfate, phosphate or acid phosphate, acetate, lactate, citrate or acid citrate, tartrate or bitartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate and pamoate [i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)] salts.
Those compounds of the formula I which are also acidic in nature, e.g., where R 4 includes a 6-azauracil or barbituric acid moiety, are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include the alkali metal or alkaline-earth metal salts and particularly, the sodium and potassium salts. These salts are all prepared by conventional techniques. The chemical bases which are used as reagents to prepare the pharmaceutically acceptable base salts of this invention are those which form non-toxic base salts with the herein described acidic compounds of formula I. These non-toxic base salts include those derived from such pharmacologically acceptable cations as sodium, potassium, calcium and magnesium, etc. These salts can easily be prepared by treating the corresponding acidic compounds with an aqueous solution containing the desired pharmacologically acceptable cations, and then evaporating the resulting solution to dryness, preferably under reduced pressure. Alternatively, they may also be prepared by mixing lower alkanolic solutions of the acidic compounds and the desired alkali metal alkoxide together, and then evaporating the resulting solution to dryness in the same manner as before. In either case, stoichiometric quantities of reagents are preferably employed in order to ensure completeness of reaction and maximum product yields.
The activity of the compounds of the invention for the various disorders described above can be determined according to one or more of the following assays.
Pharmacological Analysis
Certain compounds such as benzoylbenzoyl adenosine triphosphate (bbATP) are known to be agonists of the P2X 7 receptor, effecting the formation of pores in the plasma membrane (Drug Development Research (1996), 37(3), p. 126). Consequently, when the receptor is activated using bbATP in the presence of ethidium bromide (a fluorescent DNA probe), an increase in the fluorescence of intracellular DNA-bound ethidium bromide is observed. Alternatively, the propidium dye YOPRO-1 can be substituted for ethidium bromide so as to detect uptake of the dye. The increase in fluorescence can be used as a measure of P2X 7 receptor activation and therefore to quantify the effect of a compound on the P2X 7 receptor.
In this manner, the compounds of the invention can be tested for antagonist activity at the P2X 7 receptor. 96-Well flat bottomed microtitre plates are filled with 250 μl of test solution comprising 200 μl of a suspension of THP-1 cells (2.5×10 6 cells/ml, more preferably prestimulated as described in the literature with a combination of LPS and TNF to promote receptor expression) containing 10 −4 M ethidium bromide, 25 μl of a high potassium, low sodium buffer solution (10 mM Hepes, 150 mM KCl, 5 mM D-glucose and 1.0% FBS at pH 7.5) containing 10 −5 M bbATM, and 25 μl of the high potassium buffer solution containing 3×10 −5 M test compound (more preferably 5×10 −4 M, more preferably 1×10 −4 M. more preferably 1×10 −3 M). The plate is covered with a plastic sheet and incubated at 37° C. for one hour. The plate is then read in a Perkin-Elmer fluorescent plate reader, excitation 520 nm, emission 595 nm, slit widths: Ex 15 nm, Em 20 nm. For the purposes of comparison, bbATP (a P2X 7 receptor agonist) and pyridoxal 5-phosphate (a P2X 7 receptor antagonist) can be used separately in the test as controls. From the readings obtained, a pIC 50 figure can be calculated for each test compound, this figure being the negative logarithm of the concentration of test compound necessary to reduce the bbATP agonist activity by 50%.
In like manner, the compounds of the invention can be tested for antagonist activity at the P2X 7 receptor using the cytokine IL-1 β as the readout. Blood collected from normal volunteers in the presence of heparin is fractionated using lymphocyte separation medium obtained from Organon Technica (Westchester, Pa.). The region of the resulting gradient containing banded mononuclear cells is harvested, diluted with 10 ml of Maintenance Medium (RPMI 1640, 5% FBS, 25 mM Hepes, pH 7.2, 1% penicillin/streptomycin), and cells are collected by centrifugation. The resulting cell pellet was suspended in 10 ml of Maintenance Medium and a cell count was performed. In an average experiment, 2×10 5 mononuclear cells are seeded into each well of 96-well plates in a total volume of 0.1 ml. Monocytes are allowed to adhere for 2 hours, after which the supernatants are discarded and the attached cells are rinsed twice and then incubated in Maintenance Medium overnight at 37° C. in a 5% CO 2 environment.
The cultured monocytes can be activated with 10 ng/ml LPS ( E. coli serotype 055:B5; Sigma Chemicals, St. Louis, Mo.). Following a 2-hour incubation, the activation medium is removed, the cells are rinsed twice with 0.1, ml of Chase Medium (RPMI 1640, 1% FBS, 20 mM Hepes, 5 mM NaHCO 3 , pH 6.9), and then 0.1 ml of Chase Medium containing a test agent is added and the plate is incubated for 30 minutes; each test agent concentration can be evaluated in triplicate wells. ATP then is introduced (from a 100 mM stock solution, pH 7) to achieve a final concentration of 2 mM and the plate is incubated at 37° C. for an additional 3 hours. Media were harvested and clarified by centrifugation, and their IL-1β content was determined by ELISA (R&D Systems; Minneapolis, Minn.).
The compositions of the present invention may be formulated in a conventional manner using one or more pharmaceutically acceptable carriers. Thus, the active compounds of the invention may be formulated for oral, buccal, intranasal, parenteral (e.g., intravenous, intramuscular or subcutaneous), topical or rectal administration or in a form suitable for administration by inhalation or insufflation.
For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinized maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolate); or wetting agents (e.g., sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters or ethyl alcohol); and preservatives (e.g., methyl or propyl p-hydroxybenzoates or sorbic acid).
For buccal administration, the composition may take the form of tablets or lozenges formulated in conventional manner.
The compounds of formula I can also be formulated for sustained delivery according to methods well known to those of ordinary skill in the art. Examples of such formulations can be found in U.S. Pat. Nos. 3,538,214, 4,060,598, 4,173,626, 3,119,742, and 3,492,397, which are herein incorporated by reference in their entirety.
The active compounds of the invention may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.
The active compounds of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
For intranasal administration or administration by inhalation, the active compounds of the invention are conveniently delivered in the form of a solution, dry powder formulation or suspension from a pump spray container that is squeezed or pumped by the patient or as an aerosol spray presentation from a pressurized container or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, heptafluoroalkanes, carbon dioxide or other suitable gas. In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container or nebulizer may contain a solution or suspension of the active compound. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.
A proposed dose of the active compounds of the invention for oral, parenteral or buccal administration to the average adult human for the treatment of the conditions referred to above (inflammation) is 0.1 to 200 mg of the active ingredient per unit dose which could be administered, for example, 1 to 4 times per day.
The compound of formula (I) and pharmaceutically acceptable salts and solvates thereof may be used on their own but will generally be administered in the form of a pharmaceutical composition in which the formula (I) compound/saltisolvate (active ingredient) is in association with a pharmaceutically acceptable adjuvant, diluent or carrier. Depending on the mode of administration, the pharmaceutical composition will preferably comprise from 0.05 to 99% w (percent by weight), more preferably from 0.10 to 70% w, of active ingredient, and, from 1 to 99.95% w, more preferably from 30 to 99.90% w, of a pharmaceutically acceptable adjuvant, diluent or carrier, all percentages by weight being based on total composition.
Aerosol formulations for treatment of the conditions referred to above in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains 20 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
Aerosol combination formulations for treatment of the conditions referred to above (e.g., adult respiratory distress syndrome) in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains from about 1 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
Aerosol formulations for treatment of the conditions referred to above (e.g., adult respiratory distress syndrome) in the average adult human are preferably arranged so that each metered dose or “puff” of aerosol contains from about 20 μg to 1000 μg of the compound of the invention. The overall daily dose with an aerosol will be within the range 100 μg to 10 mg of the p38 kinase inhibitor. Administration may be several times daily, for example 2, 3, 4 or 8 times, giving for example, 1, 2 or 3 doses each time.
This invention also encompasses pharmaceutical compositions containing and methods of treating or preventing comprising administering prodrugs of compounds of the formula I. Compounds of formula I having free amino, amido, hydroxy or carboxylic groups can be converted into prodrugs. Prodrugs include compounds wherein an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues which are covalently joined through peptide bonds to free amino, hydroxy or carboxylic acid groups of compounds of formula I. The amino acid residues include the 20 naturally occurring amino acids commonly designated by three letter symbols and also include, 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline homocysteine, homoserine, ornithine and methionine sulfone. Prodrugs also include compounds wherein carbonates, carbamates, amides and alkyl esters which are covalently bonded to the above substituents of formula I through the carbonyl carbon prodrug sidechain.
The following Examples illustrate the preparation of the compounds of the present invention. Melting points are uncorrected. NMR data are reported in parts per million (d) and are referenced to the deuterium lock signal from the sample solvent (deuteriochloroform unless otherwise specified). Mass Spectral data were obtained using a Micromass ZMD APCI Mass Spectrometer equipped with a Gilson gradient high performance liquid chromatograph. The following solvents and gradients were used for the analysis. Solvent A; 98% water/2% acetonirile/0.01% formic acid and solvent B; acetonitrile containing 0.005% formic acid. Typically, a gradient was run over a period of about 4 minutes starting at 95% solvent A and ending with 100% solvent B. The mass spectrum of the major eluting component was then obtained in positive or negative ion mode scanning a molecular weight range from 165 AMU to 1100 AMU. Specific rotations were measured at room temperature using the sodium D line (589 nm). Commercial reagents were utilized without further purification. THF refers to tetrahydrofuran. DMF refers to N,N-dimethylformamide. Chromatography refers to column chromatography performed using 32–63 mm silica gel and executed under nitrogen pressure (flash chromatography) conditions. Room or ambient temperature refers to 20–25° C. All non-aqueous reactions were run under a nitrogen atmosphere for convenience and to maximize yields. Concentration at reduced pressure means that a rotary evaporator was used.
One of ordinary skill in the art will appreciate that in some cases protecting groups may be required during preparation. After the target molecule is made, the protecting group can be removed by methods well known to those of ordinary skill in the art, such as described in Greene and Wuts, “Protective Groups in Organic Synthesis” (2 nd Ed, John Wiley & Sons 1991).
EXAMPLE 1
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-hexyl)-benzamide
A: 2-(3-Carboxy-4-chloro-phenyl)-3,5-dioxo-2,3,4,5-tetrahydro-[1,2,4]triazine-6-carboxylic acid
To a mechanically stirred solution of 5-amino-2-chloro-benzoic acid methyl ester (5.0 g, 26.9 mmol) in glacial acetic acid (100 ml) was added 12 N hydrochloric acid (7.5 ml). After 30 minutes at room temperature the reaction mixture was cooled to 10° C. and a solution of NaNO 2 in water (5 ml) was added dropwise at a rate that kept the reaction temperature between 10° and 15° C. During this time it was observed that the reaction went from purple to light brown. After stirring for 30 minutes at 10° C. sodium acetate (5.4 g) followed by (3-ethoxycarbonylamino-3-oxo-propionyl)-carbamic acid ethyl ester (7.2 g) were added at once. After stirring for 20 minutes at 10° C. followed by 1 hour at room temperature an additional 2.2 g of sodium acetate was added. After stirring at reflux for 6 hours the reaction mixture was cooled to room temperature and 50% aqueous sulfuric acid (29 ml) was added. After stirring the resulting mixture at reflux for 2 hours the mixture was cooled to room temperature, diluted with water (135 ml) and filtered. The precipitate was washed with water and dried under vacuum. The crude solid was recrystallized from isopropyl ether to give 3.8 g (46%) of the title intermediate as an orange solid. Mass spec [M−1] 3:1 ratio of 310.1 and 312.1; 1 H nmr (500 MHz, CD 3 OD) δ 7.64 (d, J=8.8 Hz, 1H), 7.75 (d, J=8.8 Hz, 1H), 8.14 (d, J=2.6 Hz, 1H).
B: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid
A suspension of 2-(3-carboxy-4-chloro-phenyl)-3,5-dioxo-2,3,4,5-tetrahydro-[1,2,4]triazine-6-carboxylic acid (3.4 g) in mercaptoacetic acid (2 ml) was stirred at 175° C. After 20 h the resulting solution was cooled to room temperature during which time a precipitate formed. The mixture was dumped into ice-water, stirred for 30 minutes and filtered to give a yellow solid. The solid was dried under vacuum for 24 hours to give 2.1 g of the title intermediate. Mass spectrum [M−1] 3:1 ratio of 266.1 and 268.1; 1 H nmr (500 MHz, CD 3 OD) δ 7.58 (s, 1H), 7.60 (d, J=8.8 Hz, 1H), 7.72 (dd, J=2.6 and 8.8 Hz), 8.09 (d, J=2.6 Hz).
C: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoyl chloride
A mixture of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid (50 mg) in thionyl chloride (1 ml) was stirred at reflux for 1 hour. The mixture was concentrated under vacuum to provide 50 mg of the title intermediate as an amorphous amber solid that was used immediately in the next step.
D: 2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-(2-ethyl-hexyl)-benzamide
To a solution of 2-ethylhexylamine (15 mg, 0.125 mmol) in dichloroethane (1 ml) was added diisopropylethylamine resin (60 mg, 0.225 mmol) followed by a solution of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoyl chloride (21 mg, 0.075 mmol) in a 3:1 mixture of dichloroethane and THF (15 ml). The reaction mixture was shaken for 16 hours and filtered. The filtrate was treated with MP-carbonate resin (75 mg, 0.225 mmol) and the resulting mixture was shaken for 3 hours. The mixture was filtered and the resin washed with dichloromethane followed by 9:1 methanol/acetic acid. The combined filtrates were concentrated under reduced pressure to give the title compound as an amorphous solid. Mass spec [M−1] 3:1 ratio of 377.2 and 379.2; 1 H nmr (500 MHz, CDCl 3 ) δ 0.92 (t, 3H), 0.96 (t, 3H), 1.26–1.66 (m, 9H), 3.46 (m, 2H), 6.26 (broad s, 1H), 7.51 (d, 1H), 7.59–7.62 (m, 2H), 7.94 (s, 1H), 8.72 (broad s, 1H).
Examples 2–44 are presented in Table 1 and were prepared analogously to the synthesis outlined in Example 1D, coupling the appropriate amine to 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoylbenzoyl chloride. In some examples the product was purified by preparative HPLC using a Shimadsu LC-8A preparative liquid chromatograph. All final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A=98% Water+2% Acetonitrile+0.01% Formic Acid
Solvent B=Acetonitrile+0.005% Formic Acid
TABLE 1
Mass
LC
Mass Spectra
Spectra
Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
2
351.2
349.2
2.2
3
399.1
397.0
2.4
4
405.0
403.0
2.3
5
371.1
369.0
2.0
6
451.0
448.9
2.3
7
389.1
387.0
2.1
8
441.0
436.9
2.3
9
401.1
399.0
2.2
10
405.0
403.0
2.2
11
337.1
335.1
2.1
12
389.1
387.0
2.0
13
447.1
445.0
2.4
14
415.1
413.0
2.3
15
481.0
479.0
2.3
16
379.2
377.1
2.7
17
405.0
403.0
2.2
18
439.0
438.9
2.5
19
351.2
349.1
2.3
20
389.1
387.0
2.1
21
363.2
361.1
2.2
22
441.0
439.0
2.4
23
385.1
383.0
2.3
24
377.1
375.0
1.9
25
421.7
419.8
2.0
26
375.6
373.7
2.4
27
421.9
419.6
2.1
28
375.8
373.8
2.4
29
385.2
383.1
2.2
30
421.1
419.1
1.9
31
405.2
403.1
1.7
32
429.2
427.1
2.0
33
477.2
475.2
2.6
34
403.3
401.2
2.6
35
387.2
385.1
1.5
36
413.2
411.1
2.0
37
417.2
415.1
2.2
38
401.2
399.1
2.0
39
403.3
401.2
2.6
40
439.3
437.2
2.6
41
401.5
399.6
2.1
42
481.5
479.5
2.2
43
453.3
451.2
2.8
44
425.3
423.2
2.5
45
510.1
508.1
2.4
46
475.2
473.2
2.2
47
429.5
427.5
2.7
EXAMPLE 48
2-Chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-N-[2-(2-trifluoromethyl-phenyl)-ethyl]-benzamide
To a stirred solution of 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid (75 mg, 0.3 mmol), EDCl (60 mg) and HOBT (50 mg) in DMF (3 ml) was added 2-(2-trifluoromethylphenyl)ethylamine (53 mg, 0.3 mmol). After 30 minutes triethylamine (45 μl) was added. After 3 hours the reaction mixture was diluted with ethyl acetate (75 ml) and washed sequentially with water and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated under vacuum to give 73 mg of an amorphous solid. The solid was purified by silica gel chromatography eluting with 1:1 ethylacetate/hexanes, followed by crystallization from isopropyl ether to give 36 mg of the title compound as a white solid.
Melting Point=148–150° C.; Mass spectra [M−1] 437.6; Mass spectra [M+1] 439.9.
Examples 49–50 are presented in Table 2 and were prepared analogously to the synthesis outlined in Example 48, coupling the appropriate amine to 2-chloro-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid. Final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A=98% Water+2% Acetonitrile+0.01% Formic Acid
Solvent B=Acetonitrile+0.005% Formic Acid
TABLE 2
LC
Mass Spectra
Mass Spectra
Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
49
419.5
417.5
2.4
50
379.4
377.4
1.6
EXAMPLE 51
N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-yl)-2-methyl-benzamide
A: 2-Methyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid
5-Amino-2-chloro-benzoic acid methyl ester (3.5 g, 21.2 mmol) was dissolved in glacial acetic acid (80 ml) and 5.5 ml of concentrated HCl was added. After stirring with an overhead stirrer for 30 minutes at ambient temperature the mixture was cooled to 10° C. and a solution of NaNO 2 (1.6 g) in water (4 ml) was added dropwise, keeping the internal temperature below 15° C. During this addition the reaction mixture changed from amber to a cloudy orange. After 30 minutes sodium acetate (3.8 g, 46.6 mmol) and (3-ethoxycarbonylamino-3-oxo-propionyl)-carbamic acid ethyl ester (5.7 g, 23.3 mmol) were added at once. After 10 minutes the reaction was warmed to ambient temperature. After 1 hour additional sodium acetate (1.7 g, 21.2 mmol) was added and the reaction mixture was heated at reflux. After 3 hours the deep red-brown mixture was treated with 50% sulfuric acid (23 ml) and heated again at reflux. After 2 hours the mixture was concentrated under reduced pressure and then water (200 ml) was added. After stirring for 30 minutes the gold precipitate (3.5 g) was collected by filtration. The resulting solid was suspended in 3 ml of mercaptoacetic acid and stirred at 175° C. After 4 hours the mixture was allowed to cool and sit for 16 hours. The mixture was diluted with water (100 ml) and stirred for 1 hour. The resulting brown solid (2.1 g) was collected by filtration. Mass spectrum [M−1] 246.4.
B: N-[2-(2-Chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-2-methyl-benzamide
The title compound was prepared using the method outlined in Example 48, coupling 2-methyl-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzoic acid with 2-(ortho-chlorophenyl)ethylamine. The product was a colorless oil. MS (ES+) 385.2; (ES−) 383.2; LC retention time=2.1 min (using the LC/MS and method outlined for the examples in Table 1).
EXAMPLE 52
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(4-methyl-3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide
To a stirred solution of 2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(3,5-dioxo-4,5-dihydro-3H-[1,2,4]triazin-2-yl)-benzamide (70 mg, 0.173 mmol) in dioxane (1.5 ml) was added methanol (0.36 ml) followed by a 2.0 M solution of (trimethylsilyl)diazomethane (0.35 ml). After stirring for 16 hours at ambient temperature the mixture was concentrated under reduced pressure to give 75 mg of a white amorphous solid. Purification by silica gel chromatography eluting with 2:1 hexaned/ethyl acetate provided 39 mg of the title compound as a white amorphous solid. Melting Point 157–161° C.;
Mass Spectrum (ES+) 419.2; (ES−) 417.1; LC retention time=2.4 minutes (using the LC/MS and method outlined for the examples in Table 1).
EXAMPLE 53
2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide
A: 5-Bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide
To a stirred solution of 2-chloro-5-bromobenzoic acid (1.5 g, 6.3 mmol), EDCI (1.63 g, 8.5 mmol), and HOBT (1.15 g, 8.5 mmol) in DMF (20 ml) was added 2-(2-chlorophenyl)ethylamine (1.06 ml, 7.5 mmol). After 15 minutes triethylamine (1.18 ml, 8.5 mmol) and DMF (5 ml) was added. After 2 hours at ambient temperature the mixture was diluted with ethyl acetate (50 ml) and washed with 1N HCl followed by a saturated solution of sodium bicarbonate, followed by water, and then brine. The organic layer was separated and dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 2.12 g of an amorphous solid. Mass Spectrum (ES+) 374.6, (ES−) 372.2.
B: 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(2-oxo-piperidin-1-yl)-benzamide
A mixture of 5-bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide (200 mg, 0.536 mmol), δ-valerolactam (106 mg, 1.07 mmol), potassium carbonate (156 mg, 1.13 mmol), dioxane (1 ml, purged with nitrogen), and copper (I) iodide (5 mg) in an oven-dried round bottom flask equipped with a reflux condenser under a nitrogen atmosphere was heated in an oil bath at 120–125)C. After 21 hours the mixture was cooled to room temperature, filtered through a pad of silica gel and concentrated under reduced pressure to give 50 mg of crude product. Purification by preparative HPLC (Shimadsu LC-8A preparative liquid chromatograph) eluting with a gradient of 0.1% aqueous formic acid in acetonitrile provided 2.5 mg of the title compound as a colorless amorphous solid. Mass Spectrum (ES+) 391.6; LC retention time=2.3 minutes (using the LC/MS and method outlined for the examples in Table 1).
Examples 54–57 are presented in Table 3 and were prepared analogously to the synthesis outlined in Example 53, coupling the appropriate lactam to 5-bromo-2-chloro-N-[2-(2-chloro-phenyl)-ethyl]-benzamide. In some examples the product was purified by preparative HPLC using a Shimadsu LC-8A preparative liquid chromatograph. All final products were analyzed by LC/MS using a Micromass ZMD LC/MS (ESI mode). The method used for the HPLC mobile phase gradient change was as follows:
Time (min)
A %
B %
0.00
95
5
1.0
80
20
2.3
50
50
3.7
0
100
3.7
95
5
Solvent A=98% Water+2% Acetonitrile+0.01% Formic Acid
Solvent B=Acetonitrile+0.005% Formic Acid
TABLE 3
LC
Mass Spectra
Mass Spectra
Retention
Ex.
Structure
(ES+)
(ES−)
Time (min)
54
417.7
—
2.3
55
434.3
—
2.1
56
379.8
—
2.4
57
457.1
—
2.8
EXAMPLE 58
2-CHLORO-N-[2-(2-CHLORO-PHENYL)-ETHYL]-5-(5-OXO-1,5-DIHYDRO-[1,2,4]TRIAZOL-4-YL)-BENZAMIDE
A: 2-Chloro-5-phenoxycarbonylamino-benzoic acid methyl ester
To a stirred mixture of 5-amino-2-chloro-benzoic acid methyl ester hydrochloride (1.110 g, 5.0 mmol) and pyridine (0.79 g, 10.0 mmol) in anhydrous THF (15 mL) at 0° C. was added phenylchloroformate (0.95 g, 6.0 mmol). After warming to room temperature, the reaction mixture was diluted with ethylacetate (50 mL), washed sequentially with 10% HCl, water and brine and dried over sodium sulfate. Removal of solvent under vacuum and purification of the product by flash chromatography (10% ethyl acetate in hexanes) yielded 0.8 g (53%) of a colorless solid. 1 H NMR (300 MHz, DMSO-d 6 ) δ3.9 (s, 3H), 7.0 (br s, 1H), 7.18 (m, 2H), 7.4 (m, 3H), 7.6 (m, 1H), 7.9 (d, J=2.5 Hz, 1H). Mass Spectrum (M−H): 3:1 ratio of 304 and 306.
B: 1-Formyl-4-(2-Chloro-5-carbomethoxyphenyl)semicarbazide:
To a solution of 2-chloro-5-phenoxycarbonylamino-benzoic acid methyl ester (0.22 g, 0.72 mmol) in dimethyl sulfoxide (1.4 mL) was added formic hydrazide (0.135 g, 3.15 mmol). After stirring at room temperature for 20 hours, the reaction mixture was partitioned between ethyl acetate and 1.0 N HCl. The organic phase was washed with brine, dried and concentrated in vacuo. The residue was purified on silica gel (30% methanol in ethyl acetate) to yield 0.03 g (17%) of a colorless solid: Mass Spectrum: (M+H) 3:1 ratio of 272 and 274.
C: 2-Chloro-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid
A solution of 1-formyl-4-(2-chloro-5-carbomethoxyphenyl)semicarbazide (0.03 g, 0.11 mmol) in 1.0 M KOH in methanol (MeOH) (0.44 mL) was heated at 80° C. for 72 hours and cooled to room temperature. 1.0 N HCl (0.8 mL) was added and the mixture evaporated to dryness in vacuo. The residue was taken up in MeOH (1.5 mL) and filtered. The filtrate was concentrated in vacuo to yield 0.028 g (100%) of the title intermediate as an amorphous solid. Mass Spectrum (M−H): 3:1 ratio of 238 and 240.
D: 2-Chloro-N-[2-(2-chloro-phenyl)-ethyl]-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzamide
To a solution of 2-chloro-5-(5-oxo-1,5-dihydro-[1,2,4]triazol-4-yl)-benzoic acid (0.028 g, 0.117 mmol) in anhydrous dimethyl fomamide (DMF) (4 mL) was added 1-hydroxybenzotriazole (0.018 g, 0.14 mmol). After stirring at room temperature for 10 minutes, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.025 g, 0.13 mmol) was added. After stirring at room temperature for 30 minutes, 2-chlorophenethylamine (0.018 g, 0.12 mmol) and triethylamine (0.012 g, 0.12 mmol) were added and the mixture stirred at room temperature overnight. The reaction mixture was diluted with EtOAc, washed sequentially with water and brine, and dried over sodium sulfate. Removal of solvent in vacuo followed by purification by reverse phase HPLC yielded 0.042 g (10%) of the title compound as a colorless solid. 1 H NMR (300 MHz, CDCl 3 ) δ (m, 2H), 3.45 (m, 2H), 7.25 (m, 2H), 7.35 (m, 2H), 7.60 (d, J=7.9 Hz, 1H), 7.76 (s, 1H), 7.78 (s, 1H), 8.43 (s, 1H) and 8.64 (m, 1H). Mass Spectrum (M−H) 3:1 Ratio of 375 and 377. | The present invention relates to novel to P2X 7 inhibitors of formula I
and to processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them, and their use in therapy. The active compounds of the present invention are potent inhibitors of P2X 7 and as such are useful in the treatment of inflammation, osteoarthritis, rheumatoid arthritis, cancer, reperfusion or ischemia in stroke or heart attack, autoimmune diseases and other disorders. | 2 |
BACKGROUND OF THE INVENTION
The invention is directed to improvements in fuel injection pumps whose supply pressure is controllable by a valve in accordance with at least one operating characteristic of the engine.
In a fuel injection pump of this type, disclosed in F.R.G. Pat. No. 19 13 808, the valve, in the form of an electrically controllable valve, is disposed in the fuel supply line leading from the fuel supply chamber of the pump to the pump work chamber. The valve is a magnetic valve, the closing member of which is located in the closing position when the coil is not excited. When the fuel injection pump is in operation, the magnetic valve is moved into its opening position by an rpm signal and is kept there until such time as the rpm exceeds a predetermined value. When this value is exceeded the result is an interruption of the supply of electric current to the magnetic valve, so that the fuel supply line is closed by the closing member of the magnetic valve. The rpm threshold value is detected via fuses located in the current supply circuit of the magnetic valve, which via a response value limit the rpm-dependent current load on the magnetic valve. The control provided in the known apparatus serves to shut off the engine if the maximum rpm is exceeded.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the invention to provide a fuel injection pump having the advantage over the prior art that the engine can continue to be operated even if an unusual operating condition should arise. Because of the pressure drop in the fuel supply chamber that is produced by the controllable valve in the intake line or bypass line, the extent to which the pump work chamber is filled by the individual intake strokes of the pump piston is advantageously decreased, and thus the supply of fuel to the engine associated with the fuel injection pump is decreased as well. This action takes place independently of a control device otherwise provided for controlling the fuel injection quantity. In this way, the maximum vehicle speed or maximum rpm of the engine driving the vehicle can be limited on the one hand, and on the other hand emergency operation of the engine is possible in the event that the associated control device for the fuel injection quantity should fail.
It is another object of the invention to provide fail-safe operation whenever an electronic control unit is provided as the control device. The person operating the machine is then capable of arbitrarily actuating the valve. The engine can be driven at low load if the intake line or bypass line is opened or closed in a throttled manner. If the intake line is fully open, then an injection quantity adjustment takes place, corresponding to a defined position of the quantity control element controlled by the control device.
A further effect of throttling the intake line or the bypass line is that because of the attendant decreasing pressure in the fuel supply chamber, the control of injection time that is provided for the fuel injection pump is varied as well; for instance, with rpm-dependent pressure control in the fuel supply chamber, the injection onset is shifted toward "late". This in turn has the further effect of reducing the efficiency of the fuel injection pump, so that the rpm or power of the engine is reduced and the engine is in danger of overheating. This problem is alleviated by providing a means by which the injection time control can be brought to a conventional mean value position despite the reduction in fuel pressure in the fuel supply chamber.
It is yet another object of the invention that controlling a reduced pressure by adjusting the valve is advantageously facilitated by relieving the fuel supply chamber via a pressure maintenance valve, rather than via an open throttle connection.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first exemplary embodiment of the invention in a partially schematic arrangement having a valve located in the intake line or in the bypass line around the overflow throttle and being switchable upon exceeding a set maximum rpm or for shutting off the engine;
FIG. 2 is another version of the exemplary embodiment of FIG. 1, showing an additional feed pump for supplying an injection adjuster with pressure medium; and
FIG. 3 shows a third exemplary embodiment, based on FIG. 1, having a controllable cross section in the intake line or in the bypass line around the overflow throttle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the exemplary embodiment shown in FIG. 1, a cylinder bore 2 is provided in a pump housing 1 of a fuel injection pump. A pump piston 3 defines a pump work chamber 4 in the cylinder bore 2. The pump piston is driven in rotation by means not shown via a cam disk 5, which runs on a roller ring 6 (in this drawing, this is shown offset by 90° into the plane of the drawing), and as it rotates it executes a reciprocating pumping movement with an intake stroke and a supply stroke. The supply of fuel to the pump work chamber is effected via a fuel supply conduit 8, which leads from a fuel supply chamber 9 into the cylinder 2, its entry being controlled via longitudinal grooves 10 originating at the end face of the pump piston. The fuel supply chamber is located inside the pump housing and is supplied with fuel by means of a fuel feed pump 12, which is driven synchronously with the pump piston. To this end, the fuel feed pump communicates via an intake line 14 with a fuel supply tank 15. Parallel to the fuel feed pump, there is a pressure control valve 16, by means of which, beyond the rpm-dependent pumping of the fuel feed pump, the pressure in the fuel supply chamber 9 is controlled. In order to perform control of the instant of injection, this pressure is preferably dependent on the rpm at which the fuel injection pump is driven.
The pump piston protrudes into the fuel supply chamber on the side toward the cam disk and this part of the pump piston has an annular slide 18, with the upper edge of which the outlet of a transverse bore 19 on the pump piston into the fuel supply chamber 9 can for instance be controlled. A longitudinal bore 20 begins at the transverse bore 19 and communicates continuously, as a relief conduit, with the pump work chamber 4. Branching off from this relief conduit is a radial bore 21 that discharges into a distributor groove 22. As the pump piston rotates, this groove 22 is brought into successive communication with one fuel injection line 24 at a time. The fuel injection lines are disposed on the circumference of the cylinder bore 2 in the operative region of the distributor groove 22 in accordance with the number of engine cylinders to be supplied.
The annular slide 18 serves to control fuel quantity and is axially displaced on the pump piston by an electromagnetic final control element 25; the quantity of fuel pumped into one of the injection lines per pumping stroke of the pump piston is the greater, the more the annular slide 18 is displaced toward top dead center of the pump piston. The electromagnetic final control element 25 is controlled by a control device that emits a control signal to the electromagnetic final control element in accordance with operating parameters. As operating parameters, the rpm of the engine is detected via an rpm transducer 26, which cooperates with a gear disk 28 coupled to the drive shaft 27 of the fuel injection pump. The position assumed by the electromagnetic final control element 25 is also detected by a feedback transducer 29, and the location of the instant of injection for overall injection control is ascertained with an injection time transducer 30. In this exemplary embodiment, this may be a transducer that detects the position of the roller ring, but other injection time transducers, such as needle stroke transducers and the like, may also be provided. Via a gas pedal 32, the torque desired by the driver operating the engine is fed to the control device 23. Other parameters, such as the temperature T or the density of the air supplied to the engine combustion chambers, can be taken into account in forming the fuel quantity signal. Controls of this kind are well known and need no further description here.
To adjust the injection timing, an injection adjuster piston 34 is also provided, which is displaceable in a working cylinder 35 and is coupled with the roller ring 6. One side of the injection adjusting piston 34 is loaded by a restoring spring 37 and the other side encloses a work chamber 38 in the working cylinder; the work chamber 38 communicates with the fuel supply chamber 9 via a throttle 39. As the pressure in the fuel supply chamber rises with the increasing rpm, the injection adjuster piston 34 is displaced counter to the force of the spring 37 and thereby rotates the roller ring 6 such that the piston stroke movement takes place at an earlier rotational angle of the injection pump drive shaft 27.
The above-described system relates to a known fuel injection pump of the distributor pump type, having electrical control. Electrical controls of this kind may fail for various reasons, or may malfunction, and so supplementary measures are advantageously provided to assure that a maximum rpm of the engine supplied by the fuel injection pump cannot be exceeded, to enable reliable shutoff of the engine, and to maintain emergency operation of the engine if the electric control unit should fail. In this emergency operation, it must be assured that the engine can be operated at least at low load until such time as the vehicle can escape from a dangerous situation or can be driven under its own power to a repair facility. To this end, a valve 41 is provided in the intake line 14, located downstream of where the relief line leading from the pressure control valve discharges into the intake line. In the example shown in FIG. 1, the valve 41 is an electromagnetically actuated switching valve that is triggered by the control unit 23. This control unit has supplementary electronics, which if a maximum permissible rpm is exceeded emits a control signal via a control line 42 to the magnetic coil 43 of the magnetic valve 41. If the permissible rpm is exceeded, the magnetic valve 41 is closed, so that the fuel feed pump 12 cannot pump any more fuel into the fuel supply chamber. The internal pressure in the chamber then drops, and in the individual intake strokes of the pump piston 3, the pump work chamber is no longer filled completely, or is filled at reduced pressure. The injection pumping capacity of the pump piston drops accordingly, and the fuel injection quantity is reduced. As a result, the rpm, which had previously been exceeded, drops once again, and the valve 41 can be opened. In this manner, engine operation can be maintained despite a defectively operating control unit, yet without exceeding the maximum rpm.
In supplementation to this arrangement, a switch 44 is provided, in the closing position of which the control line 42 is supplied with a fixed voltage, which likewise closes the valve 41. The control unit 23 may be protected by an uncoupling diode 45 incorporated into the control line 42. The engine can be brought to a stop in a simple manner with this switch 44. The switch may be wired so as to reinforce some other shut-off provision, so that the rapid drop, effected by the switch 44, of the fuel pressure in the fuel supply chamber 9 makes the shutoff take place faster.
An alternative 47 to the above-described option for varying the fuel pressure in the fuel supply chamber 9 functions similarly. The device 47 comprises an electromagnetic valve 46, which is located in a bypass line 49 around an overflow throttle 50 and actuated by a magnetic coil 48; in a known manner, part of the fuel pumped into the fuel supply chamber 9 is diverted again by this valve 46, so as to scavenge the fuel supply chamber and keep it free of vapor bubbles. In order for this alternative to function properly, however, the then-operative cross section of the valve 46 must be relatively large, however, since the fuel pump 12 continues to introduce the entire supply quantity into the fuel supply chamber.
If the fuel injection pump is operated with the injection timing control device provided in FIG. 1, then the drop in the fuel pressure in the fuel supply chamber shifts the injection timing toward "late". However, this also lowers the efficiency of the engine, and the toxic component of the engine exhaust gases increases because of the incomplete combustion that then takes place. In particular for limiting the maximum rpm, it is accordingly advantageous to provide a supplementary measure, in which when the valve 41 in the intake line 14 is switched a minimum pressure is maintained in the work chamber 38 before the injection adjuster piston 34.
FIG. 2 schematically shows the fuel injection pump 1 with the injection timing adjuster, the work chamber 38 of which communicates via the throttle 39 with the fuel supply chamber 9. Aside from the fuel feed pump 12, an additional fuel feed pump 52 is also provided, which aspirates fuel from the fuel supply tank 15 and delivers it to the work chamber 38 via a pressure line 54 that contains a check valve 53. Between the fuel feed pump 52 and the check valve 53 a relief line 55 branches off, returning to the fuel supply tank 15; it contains a pressure limiting valve 58, by means of which the fuel pressure in the work chamber 38 can be limited to a value of 7 bar, for instance. The additional fuel feed pump 52 is triggered by the control unit 23 simultaneously with the valve 41 and put into operation as soon as the valve 41 has been put into its closing position. This assures that an at least approximate instant of injection is established, while the fuel pressure in the fuel supply chamber 9 can be dropped to a more or less great extent. This also enables better performance when the engine is put back into normal operation.
This arrangement is advantageously usable in the exemplary embodiment of FIG. 3 as well. This system contains substantially the same structural components as that of FIG. 1, except that the valve 41, which in the foregoing embodiments was in the form of a switching valve, is now embodied as a valve with a variable flow cross section. Thus an adjustable throttle 58 is provided in the intake line 14 instead of the valve 41, and this throttle 58 is provided with an actuating element 59. The actuating element is adjustable by means of an adjusting lever 60, which is actuable by the driver of the vehicle. A switch 62 is also provided, which can be switched automatically or by the vehicle driver out of a first switching position I shown in FIG. 3 into a second switching position II if the electric control unit is not functioning properly. In position I, the switch 62 supplies the control unit 23 with the operating voltage, which in position II is fed to the control unit 23 in such a way that the unit 23 moves the electromagnetic final control element 24 into a preferred position in the partial-load range.
The system of FIG. 3 described thus far operates such that in the event that the electric control unit is no longer functioning properly, the annular slide 18 that determines the injection quantity is moved into a preferred position by the final control element 25. The fuel quantity injected in this position can be still further modified by throttling the intake line 14 to a greater or lesser extent. With the lever 60, the driver of the vehicle can adjust the throttle 58 and thereby reduce the fuel pressure in the fuel supply chamber 9, for example. As a result, the fuel injection quantity that is pumped is reduced as compared with the quantity that is determined by the position of the annular slide 18. Depending upon the extent of throttling, output can be regulated for emergency operation, even within narrow limits. To this end, a check valve 64 is advantageously provided in the relief line 63 containing the overflow throttle 50; the check valve 64 establishes a minimum pressure in the fuel supply chamber 9.
This embodiment, like that of FIG. 1, can again be modified by providing an alternative 47', in which an adjustable throttle 66 is disposed parallel to the overflow throttle 50. This throttle 66 would then be adjusted by the adjusting lever 60 via an actuating lever 67, in a manner analogous to the throttle 58. Instead of a mechanical coupling between the adjusting lever 60 and the actuating lever 59 or 67, an electric coupling may be provided, in which the adjusting movement of the adjusting lever 60 is transmitted to a control circuit 68 that is activated in position II of the switch 62 and controls a control motor 69 in accordance with the angular position of the adjusting lever 60. The motor 69 adjusts the actuating member 59, counter to the force of a restoring spring 70. Once again it is particularly advantageous if the work chamber 38 can be acted upon by an additional source of control pressure, which over the duration of emergency operation assures an approximately correct instant of injection. In addition to this arrangement, the control circuit 68 or the control motor 69 may also be triggered by an excessive-rpm protecting means similarly to the exemplary embodiment of FIG. 1.
The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A fuel injection pump for internal combustion engines is described, which for controlling fuel quantity is provided with control unit that controls an electric final control element, which in turn actuates the regulating member that determines the fuel injection quantity per pump piston supply stroke. The supply of fuel to the pump work chamber is effected from a fuel supply chamber, which is kept at a controlled pressure by a fuel feed pump. To limit the maximum speed of the engine supplied by the fuel injection pump in the event of failure of the control unit, a valve is provided in the intake line of the fuel feed pump. Using this valve, the flow cross section of the intake line can be varied or closed. By means of the modification of the fuel pressure in the fuel supply chamber effected thereby, a control of the fuel injection quantity that is not dependent on the position of the quantity-determining member is attained. | 5 |
BACKGROUND OF THE INVENTION
The invention relates generally to sealed silos and more particularly to air breather bags which maintain pressure equilibrium between the inside and the outside of the sealed silo. The silo is recognized as a fundamental development in the art of storing silage and fodder materials which are utilized as feed for various farm animals. It has been determined that the storage life of various silage and fodder feed is extended markedly by preserving such feed in an atmosphere devoid of oxygen. Recently, therefore, silos have been designed to be substantially airtight to prevent the ingestion of oxygen laden air. Such a sealed silo is manufactured by A. O. Smith Harvestore Products, Inc., of Arlington Heights, Ill.
Such sealed silos may be forty to as much as sixty feet high and have diameters from twenty to thirty feet. Basically, therefore, the structures define sealed cylinders. Since they are located out of doors, they are subject to wide variations in temperature, produced by both the sun's radiant energy and ambient conditions, as well as variations in the barometric pressure. Absent a structure to compensate for the variations in internal pressure, the walls of a sealed silo would be subjected to substantial hoop stresses when the internal pressure was above the ambient and, likewise, subjected to crushing and collapsing forces when the reverse condition was true. It was therefore appreciated that a pressure equalizing device which maintained the silo in a sealed condition must be incorporated thereinto.
Such a pressure equalizing device is the air breather bag of the instant invention. Numerous designs have been suggested. Early breather device patents teach the use of long rectangular plastic breather bags or toroidal bags having a semi-circular profile. A configuration which has become somewhat standard within the industry comprises two separate arcuate, half-toroidal sections each having a circular cross section. Each half toroidal section is hung near the top of the silo with its ends generally abutting the ends of the other breather bag. The use of two half-toroid bags not only minimizes replacement costs resulting from the failure of a portion of one breather bag but also facilitates their manufacture and installation. Alternatively, three bags, each subtending an arc of approximately 120°, may be desirable to further reduce individual cost and further facilitate manufacture.
The present sophistication of silo breather bags is the result of various attempts to improve the service life of such breather bags through the strategic location of seams along lines of low stress and sealing methods which inhibit stress concentrations. An early breather bag seam configuration comprehends the use of a plurality of axially abutting bands. Such a design often utilized as many as twelve plastic panels which were formed into hoops and subsequently axially aligned and sealed. Finally, circular end panels were secured to opposite ends of the generally toroidal breather bag. The resulting breather bag exhibited a high seam length to volume ratio and was subject to early failure which invariably occurred along a seam.
Another previous design is disclosed in U.S. Pat. No. 3,888,288 to Hickle and Sherbourne which discloses a half-toroidal breather bag which includes staggered non-coextensive sealed edges which have no more than three sealed panels contiguous at any one point.
SUMMARY OF THE INVENTION
The instant invention comprehends a plastic, half-toroidal silo breather bag having a circular cross section. The three breather bag embodiments disclosed herein all comprise at least three plastic panels which are cut according to a pattern described herein and sealed along overlapping edges. Two of the panels have a dimensionally identical semi-circular outline and the third is a generally hour-glass-like shape. The distinctions between the three embodiments are associated with the various hanger structures and methods of securing such structures to the breather bag. In the preferred embodiment, an arcuate segment adjacent the chordal edge of one of the semi-collar panels is removed, a hanger strap is sealed to the bag and a second, somewhat larger arcuate segment which replaces the just-removed segment is sealed in place. The hanger strap has a plurality of openings useful for hanging the silo breather bag on hooks disposed for such purpose within the silo.
In the first alternate embodiment the hanger strap is replaced by a plurality of individual tether pads or eyelets which may be attached to the semicircular panel forming the top of the breather bag without the segment removal and resealing steps associated with the preferred embodiment.
The second alternate embodiment also utilizes the hanger strap but rather than requiring the removal of a panel segment, the panel is slit along three radial lines in the area which corresponds generally to the removed segment of the preferred embodiment. These slits facilitate the attachment of the hanger strap and are subsequently resealed with patches.
The remaining structure and assembly steps are the same for all embodiments. Two breather conduits are sealed to the panel having the hanger strap or eyelets. Four hanger eyelets are then secured to the other semi-circular panel along a line disposed similarly to the hanger strap or eyelets of the first semi-circular panel. Finally, the plastic panels are positioned with appropriate seams abutting and sealed by the application of high frequency energy.
The silo breather bag made in accordance with the foregoing has a low seam length to volume ratio and is thus less subject to seam fatigue and failure then conventional designs. Furthermore, the bag is assembled from a minimum number of segments and in the first alternate embodiment two of the three panels are identical.
It is an object of the instant invention to provide a pressure compensating silo breather bag which exhibits superior service life under extreme conditions of temperature, humidity and pressure.
It is a further object of the instant invention to provide a silo breather bag which incorporates a seam configuration having a low seam length to bag volume ratio.
It is a still further object of the invention to provide a silo breather bag having a minimum number of panels and seams which are also disposed along lines of minimum stress concentration.
Further objects and benefits of the instant invention will become apparent by reference to the following specification and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational sectional view of a sealed silo employing the instant breather bag invention;
FIG. 2 is a top plan view of a silo breather bag of the instant invention;
FIG. 3 is a side elevational view of a silo breather bag of the instant invention;
FIG. 4 is a plan view of the top and bottom semi-circular panel, the inner arcuate line representing the cutout and insert in the top panel of the preferred embodiment only which facilitates the attachment of the breather bag hanger strap;
FIG. 5 is a plan view of the hour-glass panel of the silo breather bag of the instant invention;
FIG. 6 is a top plan view of a silo breather bag according to a first alternate embodiment of the instant invention;
FIG. 7 is a side elevational view of a silo breather bag according to the first alternate embodiment of the instant invention;
FIG. 8 is an enlarged perspective view of a tether eyelet assembly of the instant invention;
FIG. 9 is a plan view of a plastic panel utilized in the tether eyelet assembly of the instant invention;
FIG. 10 is a top plan view of a silo breather bag according to a second alternate embodiment of the instant invention; and
FIG. 11 is a plan view of the top semi-circular panel according to the second alternate embodiment of the instant invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a silo breather bag of the instant invention is generally designated by the reference numeral 10. The breather bag 10 is suspended within a sealed silo 11 which contains a quantity of ensilage, fodder or other stored material 12. Each of a pair of two such breather bags 10, having a half-toroidal shape with a circular cross section, includes a hanger strap 14 having a plurality of openings 16 located therein. The openings 16 in the strap 14 are engaged with a like plurality of hooks 18 secured to the inner structure of the silo 11 which suspend the silo breather bag 10 therein. Two breather conduits 20 are secured to the breather bag 10 about two openings 21 (shown in FIG. 2). The silo 11 includes a plurality of vent openings 22 to the atmosphere, one for each breather bag 10 to be installed therein. One of the conduits 20 of the breather bag 10 is sealed about one of the openings 22 and establishes communication between the interior of the bag 10 and the atmosphere. It is necessary to connect only one of the two conduits 20 of a bag 10 to one of the openings 22, preferably the one more proximate; the other conduit 20 may be tied off.
The pressure within the breather bag 10 is generally equal to that of the outside atmosphere. When the temperature and barometric conditions begin to change such that a pressure differential between the inside and the outside of the silo is incipient, air will be ingested or exhausted through the conduits 20 and into or from the interior of the silo bag 10 to maintain pressure equilibrium. For example, if the silo 11 is exposed to sunlight, the structure will warm and an incipient pressure increase within the silo 11 will result. As the air within the silo warms and expands, air is exhausted from the breather bag 10 to maintain equal pressure within and without the silo 11. Conversely, and more importantly, as the silo 11 cools, an internal incipient pressure decrease will result in the ingestion of air through the conduits 20 and into the interior of the breather bag 10, thereby maintaining this pressure equilibrium without permitting the outside air to mix with the air inside the silo. The ingestion of air into the silo 11 due to a lower pressure within the silo than without highlights the utility and necessity of the silo breather bag 10 since, without it, oxygen laden air would be ingested into the silo 11 and hasten the deterioration of the ensilage or fodder 12 contained therein.
It is possible that the volumetric compensation which the breather bag 10 may accomplish is insufficient to ingest or exhale sufficient air to establish a pressure equilibrium between the inside and the outside of the silo 11. When this occurs, the breather bag will resiliently and harmlessly expand in an attempt to achieve pressure equilibrium. While it is clear that the resilient expansion of the bag indicates that pressure equilibrium has not been achieved (i.e., that a pressure differential does exist between the inside and the outside of the silo), it has been found that the volumetric compensation available through the use of such a silo breather bag is sufficient to at least limit the maximum pressure differential experienced under normal circumstances such that neither minor damages such as wrinkling or stress cracking nor major damage such as implosion or explosion of the silo will occur.
FIG. 2 illustrates the silo breather bag 10 in plan view. Arcuately disposed along the upper center line of the breather bag 10 is the hanger strap 14. The hanger strap 14 includes a plurality of openings 16 usable to hang the breather bag 10 within a silo as has been previously described. The hanger strap 14 is preferably secured to the breather bag 10, proper, through the use of high frequency energy sealing techniques well known in the art.
Referring to FIGS. 2 and 3, the panel and seam location can be readily seen. The upper generally semi-circular panel 30 defines an arcuate cutout which is removed to facilitate the attachment of the hanger strap 14. An arcuate insert 31, slightly larger than the cutout is subsequently positioned thereover and sealed to the panel 30. A lower semi-circular panel 40 is symmetrically positioned relative to the panel 30 but includes neither the cutout nor the insert 31 corresponding to the structures in the panel 30. The fourth panel, an hour-glass shaped inner panel 50, completes the breather bag 10 and joins the upper panel 30 and lower panel 40 in the region of the concave, vertical sidewall.
Referring now to FIG. 4, the upper panel 30 which is substantially identical to the lower panel 40 is illustrated in flat pre-assembly configuration. The upper panel 30 defines two openings 21 about which the breather conduits 20 are sealingly attached. The upper panel 30 is basically of semi-circular configuration and includes a semi-circular edge 32 having truncated terminal portions 33 and 34 which meet with edges 35 and 36, respectively, at an acute angle. The edges 35 and 36 likewise intersect a dart edge 37 and 38, respectively, at an acute angle. The dart edges 37 and 38 are joined by the chordal edge 39.
The lower breather bag panel 40 is of the same outline and dimensions as the upper panel 30. There are two distinctions, however. First, the two openings 21 for the breather conduits 20 are not present in the bottom panel 40. Secondly, the cutout and insert 31 are not needed inasmuch as no hanger strap is sealed to the lower panel 40. The numeral 40, in FIG. 4, designates the lower panel and the numerals 42-49 placed on the illustration outside the panel outline refer to the edges of the bottom panel 40 which correspond to the edges 32-39 of the top panel 30. Again, there is no numeral 41 since an insert corresponding to the insert 31 is not required in the lower panel 40.
Referring now to FIG. 5, the outline of the hour-glass shaped panel 50 is illustrated. Basically, the panel 50 comprises two vertically and horizontally symmetrical parabolic edges 51 and 52. The two parabolic edges 51 and 52 each intersect two dart edges 53A and 54A and 55A and 56A, respectively, at an acute angle. Disposed at an acute angle to the four dart edges 53A, 54A, 55A and 56A are four adjacent dart edges 53B, 54B, 55B and 56B, respectively. Intersecting the four dart edges 53B, 54B, 55B and 56B at an obtuse angle are four edges 57, 58, 59 and 60, respectively. Disposed at an obtuse angle to the four edges 57, 58, 59 and 60 are four terminal edges 61, 62, 63 and 64, respectively. Adjacent and connecting the two edges 61 and 63 is a non-symmetrical dart comprised of two edges 65A and 65B. Likewise, adjacent and connecting the two edges 62 and 64 is a non-symmetrical dart having two edges 66A and 66B.
Referring to FIGS. 3, 8 and 9, the breather bag 10 also includes a plurality of tether eyelet assemblies 74. The tether eyelet assemblies 74 are used to draw the bag away from the center of the silo 11 to facilitate loading. The tether eyelet assemblies 74 comprise a generally oval or elliptical panel of plastic 75 having two inwardly directed darts 76A and 76B symmetrically disposed about the intersection of the major axis of the panel 75 with its edge, as is seen in FIG. 9. The elliptical panel 75 is given a third dimensional or height aspect by the overlapping and sealing of the adjacent edges of the opposed darts 76A and 76B. A plastic eyelet 77 having a generally elliptical stress dispersing washer 78 is in turn secured to the plastic panel 75.
The manner of construction of the breather bag is as follows. Referring to FIGS. 2, 3 and 4, the cutout generally defined by the arcuate insert 31 is removed from the top panel 30 and the hanger strap 14 is sealed thereto. Then, the insert 31 is overlapped and sealed to the top panel 30. The openings 21 for the two breather conduits 20 are cut and the conduits 20 are installed. Next, the edge 37 is overlapped and sealed along its length to a portion of the edge 35 and likewise the edge 38 is overlapped and sealed along its length to a portion of the edge 36. In an identical fashion, the edge 47 of the bottom panel 40 is overlapped and sealed along its length to a portion of the edge 45 and the edge 48 is overlapped and sealed along its length to a portion of the edge 46. The tether eyelet assemblies 74 are affixed to the bottom panel 40 at this time.
Referring next to FIGS. 5 and 3, the hour-glass segment 50 is prepared. The four dart edges 53A and 53B, 54A and 54B, 55A and 55B and 56A and 56B are overlapped and sealed along their lengths. Likewise, the non-symmetrical dart edges 65A and 65B and 66A and 66B are overlapped and sealed.
Referring now to FIGS. 2 and 3, the upper panel 30 is positioned with its chordal edge 39 generally coincident with and slightly overlapping the three edges 51, 57 and 58 of the hour-glass panel 50 and sealed thereto. Likewise, the lower panel 40 is positioned with its edge 49 coincident with and overlapping the edges 52, 59 and 60 and sealed thereto. Next, the generally spherical ends of the breather bag 10 are formed by overlapping and sealing the following pairs of edges: 35 and 61; 36 and 62; 45 and 64; and 46 and 63. Finally, the full length seal along the convex outer periphery of the breather bag 10, comprised of the edges 32 and 42, is sealed by placing these edges in overlapping coincidence and applying sealing energy.
It will be appreciated that the breather bag manufactured according to the preceding description exhibits extended service life due to two features. First, the upper panel 30, the insert 31, the lower panel 40 and the hour-glass panel 50, shaped and cut according to this description, provide a highly accurate development of a half-toroid having generally spherical ends and a circular cross section. The panels thus accurately conform to the regular geometric shape the bag 10 assumes when it is inflated. Wrinkles, folds and excess material are therefore minimized. Secondly, and most importantly, the seams in the breather bag 10 are in regions of low stress concentration and thus are less subject to such stresses and eventual failure caused thereby than are breather bags constructed according to previous designs. It is a further consideration that this design minimizes the total length of lineal seam which further improves life. The seam length to volume ratio of the instant design is low.
A first alternate embodiment of the instant invention is illustrated in FIGS. 6-9. In FIG. 5, a breather bag 70 is illustrated which comprises an upper panel 71 identical to the upper panel 30 illustrated in FIG. 4 except that due to a unique hanger design, the cutout and arcuate insert 31 of the preferred embodiment are not required. The breather bag 70 also includes a bottom panel 72 which is identical in all respects to the bottom panel 40, illustrated in FIG. 4. The breather bag 70 further includes two breather conduits 20 which in structure and function are identical to the like numbered components of the preferred embodiment. The third panel of the first alternate embodiment breather bag 70 is an hour-glass panel 73 which is identical in all respects to the hour-glass panel 50 illustrated in FIG. 5. It should be apparent that the alternate embodiment requires a total of only three panels of plastic material. Furthermore and more importantly, the panels 71, 72 and 73 undergo no intermediate steps, that is, they need only be cut to the outlines illustrated in FIGS. 4 and 5 and sealed together along the appropriate edges. Finally, it should be clear that the first alternate embodiment of the breather bag 70 requires only two different shapes of panels since the top panel 71 and the bottom panel 72 are in all respects identical.
Referring to FIG. 8, the first alternate embodiment 70 of the breather bag 10 further comprehends the inclusion of a plurality of tether eyelet assemblies 74. The tether eyelet assemblies 74 comprise a generally oval or elliptical panel of plastic 75 having two inwardly directed darts 76A and 76B symmetrically disposed about the intersection of the major axis of the panel 75 with its edge, as is seen in FIG. 9. The elliptical panel 75 is given a third dimensional or height aspect by the overlapping and sealing of the adjacent edges of the opposed darts 76A and 76B. A plastic eyelet 77 having a generally elliptical stress dispersing washer 78 is in turn secured to the plastic panel 75. The hanger assemblies 74 are then attached to the arcuate center lines of the upper and lower panels 71 and 72 as illustrated in FIGS. 6 and 7. The final assembly of a silo breather bag 70 according to the first alternate embodiment follows the same steps as have been recited in connection with the assembly of the preferred embodiment and thus will not be here repeated.
A second alternate embodiment is illustrated in FIGS. 10 and 11. As in the first alternate embodiment the deviation from the structure of the preferred embodiment centers on the preparation of the top panel prior to the attachment of the hanger means. A second alternate embodiment of a silo breather bag 80 comprises a top panel 81, a bottom panel 82 and an hour-glass panel 83 having flat preassembly configurations and assembled seam locations which correspond to those of the preferred and first alternate embodiments of the silo breather bag of the instant invention.
The breather bag 80 likewise includes two breather conduits 20 which in structure and function are identical to the like numbered components of the preferred and first alternate embodiments. The breather bag 80 further includes a hanger strap 16 disposed along the arcuate center line of the top panel 81 in a manner identical to the preferred embodiment. The breather bag 80 further includes a plurality of tether eyelet assemblies 74 disposed along the arcuate center line of the bottom panel 82. (The eyelet assemblies 74 are not visible in FIG. 10 but are visible in and are disposed as illustrated in FIGS. 1 and 3.)
To facilitate the attachment of the hanger strap 16, the top panel 81 is prepared by cutting three radial slits 84 therein near its chordal edge. The plastic panel 81 may then be folded and maneuvered into positions which facilitate the attachment of the hanger strap 16. Subsequent to the attachment of the strap 16, the top panel 81 is spread flat and the three radial slits 84 are each resealed with an oblong patch 85. Final assembly of the breather bag 80 coincides with those steps previously enumerated with regard to the preferred embodiment.
It will be apparent that the two alternate embodiments just described exhibit the same advantages regarding extended service life as the preferred embodiment does inasmuch as they incorporate the same accurate half-toroid development, the same low stress concentration at the seams and substantially the same low seam length to volume ratio.
It will be apparent to those skilled in the art that various modifications may be made to the preferred embodiment described above without departing from the spirit and scope of the following claims. | A breather bag for use in a sealed silo maintains pressure equilibrium between the inside and the outside of the silo by its volumetric change while preventing the ingestion of oxygen laden air. The breather bag is of generally arcuate or semi-circular shape and has a generally circular cross section. The breather bag includes at least one flexible conduit which extends between the breather bag and the silo roof and provides communication between the inside of the breather bag and the atmosphere. The breather bag is comprised of at least three plastic panels which are sealed together along overlapping edges. Two of the panels are a generally semi-circular shape and the third is a generally hour-glass shape. A continuous hanger strap is sealed along the upper arcuate center line of the breather bag to facilitate hanging the bag within a silo. An alternate embodiment utilizes individual hanger pads disposed along the upper arcuate surface of the breather bag which performs the function of the hanger strap which they replace. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority benefits under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 60/612,087, filed on Sep. 21, 2004. This application also claims priority benefits under 35 U.S.C. § 119(a) to European Patent Application 04447204.1, filed on Sep. 21, 2004. U.S. Provisional Patent Application 60/612,087 and European Patent Application 04447204.1 are incorporated herein by reference in their entirety.
BACKGROUND
[0002] I. Field
[0003] This disclosure relates to methods and apparatus for creating and controlling transient cavitation in a liquid.
[0004] II. Description of Related Art
[0005] Cavitation is generally known and defined as the activity of bubbles (e.g., gas bubbles) in a liquid. Such activity includes growth, pulsation and/or collapse of bubbles in a liquid. The pulsation of bubbles is known as stable cavitation, whereas the collapse of bubbles is known as transient cavitation. The occurrence of transient cavitation can release high amounts of energy towards an area surrounding the cavitation. Such energy may be, for example, in the form of heat, shockwaves, etc.
[0006] Transient cavitation is applied in a large number of technical fields. For example, in sonochemistry, bubbles collapsing in an ultrasonic field have a catalytic effect on chemical reactions. Also, cavitation is used in medical applications, for example, as a contrast enhancer in ultrasound diagnostics. However, one of the best-known applications of cavitation may be the removal of particles from a surface of a substrate, such as a semiconductor substrate.
[0007] A common problem in these various applications is control of transient cavitation such that it occurs in a desired fashion with respect to location and mechanics of bubble collapses. For example, in substrate cleaning technology, a common problem is non-uniform removal of particles from substrate surfaces. In such applications, it is desirable that the particles being removed are removed from the substrate surface without damaging the substrate as a result of “heavy collapse” and that a uniformly cleaned surface results. This outcome is difficult to accomplish using current approaches.
[0008] Particle removal mechanisms have been previously studied for approaches that include (i) gasifying a cleaning liquid with gasses such as oxygen, nitrogen, argon, xenon, carbon dioxide, etc., or (ii) degassing a cleaning liquid. These liquids are then used to clean a wafer and sonoluminescence (SL) signals are generated by collapsing bubbles. Furthermore, after the cleaning process, particle removal efficiency is determined.
[0009] FIG. 1 is graph which demonstrates that the presence of gas in a liquid (a gasified liquid) results in achieving higher particle removal efficiency (PRE) percentages. FIG. 2 is a graph that illustrates SL signals that are plotted for gasified and degassed liquids. In gasified liquids, SL signals, generated by collapsing bubbles, can be detected as compared to a degassed liquid in which little to no SL signal is detected. The combination of FIGS. 1 and 2 illustrates that transient cavitation is one basis for particle removal in such approaches.
[0010] FIG. 3 is a graph presented by Neppiras in Acoustic Cavitation, 1980, which illustrates, that dependent on a driving pressure, a frequency of an acoustic field and gas bubble radius, gas bubbles can grow (zone Y) and then collapse when entering area Z, or may dissolve without collapse, if the bubbles are small enough to enter zone X.
[0011] In U.S. Pat. No. 6,048,405 to Skrovan (hereafter “Skrovan”), a cleaning method for use in the microelectronics industry is disclosed. In the method described in Skrovan, gas bubbles are introduced below the surface of a substrate assembly such that the bubbles pass across the surface as they rise in the liquid. In the method described in Skrovan, the substrate assembly is immersed in a region or a liquid through which megasonic energy is projected. In Skrovan, particles are released from the surface by shockwaves from the megasonic field.
[0012] As was demonstrated by FIGS. 1 and 2 , the use of megasonic energy alone is not an efficient approach for particle removal as compared to gasified liquid in combination with megasonic energy. Therefore, application of the method disclosed in Skrovan results in a non-uniform cleaning being obtained. Further, simply gasifying the liquid used in the method of Skrovan could result in substrate damage, e.g., due to heavy collapse. Thus, alternative approaches for cleaning processes using gasified liquids are desirable.
[0013] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
SUMMARY
[0014] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods, which are given by way of example and meant to be illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
[0015] Example methods for creating and controlling transient cavitation are disclosed. One such method includes creating gas bubbles having a range of bubble sizes in a liquid, creating an acoustic field and subjecting the liquid to the acoustic field. In such methods, the range of bubble sizes and/or the characteristics of the acoustic field are selected so as to control transient cavitation in the liquid for the range of bubble sizes.
[0016] The liquid may be selected from, or may be a combination of one or more of the following: (i) an aqueous solution, (ii) an organic solvent, (iii) an inorganic solvent, (iv) a polar or non-polar solvent, (v) a mixture of chemicals, or (vi) any fluid in which a gas can be dissolved or injected, such as deionized water. Such methods may be used in any number of cleaning applications, e.g. for medical equipment or for wafers in the semiconductor industry.
[0017] The characteristics of the applied acoustic field that are utilized for adjusting the character of the acoustic field may include frequency, intensity, position of a transducer or transducers, or any other parameter affecting the acoustic makeup of the field. For instance, the acoustic field may be generated using a single frequency, or may be generated using multiple frequencies.
[0018] In certain embodiments of such methods, the range of bubble sizes may be selected subsequent to and in correspondence with selected characteristics of the acoustic field. If the characteristics of the acoustic field are fixed or if the selection of those characteristics is limited, the range of bubble sizes may be adjusted in correspondence with the generated (available) acoustic field.
[0019] In other embodiments, the characteristics of the acoustic field may be selected subsequent to and in correspondence with a selected range of bubble sizes. As part of such a method, the range of bubble sizes may be determined using any number of possible approaches. If the range of bubble sizes is fixed, or if the selection of a range of bubble sizes is limited, the characteristics of the acoustic field may be adjusted in correspondence with the range of bubble sizes.
[0020] Creating gas bubbles having a selected range of bubble sizes may accomplished in any number of fashions. For example, creating the gas bubbles may include (i) dissolving gas in a liquid by means of a gasification unit or any other means to dissolve gas in the liquid; (ii) injecting gas in a liquid by means of a bubbler system, a capillary, a nozzle, a membrane contactor or any device for injecting gas bubbles into the liquid; (iii) applying a pressure drop, preferably a rapid pressure drop or applying one or multiple compression/decompression cycles; (iv) raising the temperature of a liquid, or one or more cycles of heating/cooling the liquid; (v) subjecting a liquid to an additional acoustic field; (vi) dissolving or injecting two or more different gasses into the liquid; and/or (vii) adding a surfactant to the liquid. Using the foregoing (or other) techniques, the range of bubble sizes may be varied.
[0021] An example apparatus for generating and controlling transient cavitation includes a device for creating gas bubbles having a range of bubble sizes in a liquid. The apparatus further includes an acoustic field generator for generating an acoustic field having one or more component frequencies. The acoustic field generator is acoustically coupled with the liquid. In the apparatus, at least one of (i) the device for creating gas bubbles having a range of sizes in the liquid and (ii) the acoustic field generator is adjustable so as to tune the range of bubble sizes or the acoustic field so as to control transient cavitation in the liquid for a selected range of bubble sizes.
[0022] Depending on the particular embodiment, the device for creating gas bubbles having a range of bubble sizes may include (i) a gasification unit or other device for dissolving one or more gasses in a liquid; (ii) a valve, a nozzle, a membrane contactor or other device for injecting gas bubbles (of one or more gasses) in a liquid; (iii) a heat exchanging system or any means for heating/cooling a liquid; (iv) a pressure regulating device for generating a pressure drop or generating one or multiple compression/decompression cycles; (v) a second acoustic field generator for subjecting a liquid to an additional acoustic field; and/or (vi) a device for adding a surfactant to the liquid.
[0023] Depending on the particular embodiment, apparatus for generating and controlling transient cavitation may further include a measurement unit for measuring the range of bubble sizes; and/or a control unit for controlling the device used to create gas bubbles and/or controlling the acoustic field generator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Example embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
[0025] FIG. 1 is a graph illustrating particle removal efficiency (PRE) as a function of particle size and gas concentration in a liquid;
[0026] FIG. 2 is a graph that illustrates sonoluminescence (SL) signals as a function of time and gas concentration in a liquid;
[0027] FIG. 3 is a graph that illustrates the behavior of gas bubbles in a liquid as a function of acoustic field characteristics and bubble size;
[0028] FIG. 4 is a graph that illustrates collapse as a function of bubble size and acoustic field characteristics;
[0029] FIG. 5 is a graph that illustrates temperature and pressure during collapse as a function of frequency;
[0030] FIG. 6 is a diagram that illustrates an arrangement of two pluralities of transducers that may used to implement methods as described herein;
[0031] FIG. 7 is flowchart illustrating a process flow of a particular method for generating and controlling transient cavitation;
[0032] FIG. 8 is a schematic drawing of a spray nozzle that may be used to implement methods as described herein;
[0033] FIG. 9 is a diagram illustrating the PRE for a cleaning process conducted at 1.8 MHz, 5 W/cm 2 , 2.5 bar overpressure and 18 ppm oxygen;
[0034] FIG. 10 is a diagram illustrating the PRE for a cleaning process conducted at 1.8 MHz, 5 W/cm 2 , 2.5 bar overpressure and 10 ppm oxygen; and
[0035] FIG. 11 is a graph illustrating an amount of bubbles versus saturation level.
DETAILED DESCRIPTION
[0036] The present disclosure relates to methods and apparatus for creating and/or controlling transient cavitation in a liquid. Such methods and apparatus can be used for cleaning purposes, e.g., in medical applications where sterilization is required, or in the semiconductor industry for cleaning wafers. Certain embodiments will be described with reference to certain drawings. However, it will be appreciated that these embodiments are given by way of example and not by way of limitation.
[0037] Transient cavitation is a form of cavitation where the primary activity occurring in a liquid is bubble collapse. Such bubble collapses can release high amounts of energy towards areas surrounding such collapses. For instance, energy may be released via heat, shockwaves, etc.
[0038] Methods and apparatus are disclosed herein for controlling transient cavitation in a liquid that address the problem of non-uniform cleaning performance associated with transient cavitation that was discussed above. In an example method, a specific bubble distribution is generated in a liquid (e.g., a liquid used for cleaning) and the bubbles in the distribution are brought into a specific acoustic field that corresponds with a range of bubble sizes in the distribution so as to control transient cavitation. Such a method may include (i) creating gas bubbles having a range of bubble sizes in a liquid, (ii) creating an acoustic field, and (iii) subjecting the liquid to the acoustic field. In this method, at least one of the range of bubble sizes and the acoustic field are adjusted such that transient cavitation is controlled and, for example, a substantially uniform cleaning is achieved.
[0039] Creating bubbles in the liquid can be accomplished in any number of different ways. Generally speaking, creating bubbles in the liquid includes the addition of gas to the liquid. For instance, gases such as nitrogen, oxygen, carbon dioxide, argon, helium, xenon, etc. may be added to the liquid using a gasification unit, e.g., a membrane contactor. Alternatively, (i) the ambient pressure of the liquid; (ii) the hydrostatic pressure of the liquid; (iii) the vapor pressure of the gas; (iv) the liquid flow; (v) the liquid temperature; and/or (vi) the contact area between gas and liquid are some of the parameters that may be used to control the amount of gas that is dissolved in the liquid. In certain embodiments, most of the gas will be present in a dissolved state. Increasing the pressure of the liquid and/or lowering the temperature allows for the dissolution of more gas in the liquid. It will be appreciated that the amount of gas dissolved and the saturation level for the particular gas (or combination of gasses) being dissolved in a particular liquid will have an influence on bubble formation.
[0040] Bubble formation (from the dissolved gas) may be obtained by one (or multiple) compression and decompression cycles. In such an approach, the gasified liquid may be held in a tank that allows for pressurization of the liquid (e.g., increasing the hydrostatic pressure). After pressurization of the gasified liquid, a pressure drop may be realized using a pressure-release valve to release some (or all) of the pressure above an ambient pressure from the tank.
[0041] Alternatively, a pressure drop may be achieved using a valve, an orifice or a membrane that couples two tank compartments, where one compartment is at a higher pressure (e.g., the tank containing the liquid) than the other, Opening the valve, orifice or membrane allows for equalization of pressure in the two compartments, which results in a pressure drop in the compartment that initially has the higher pressure and the creation of gas bubbles in the liquid. In such an approach, controlling the pressure differential and/or the speed of the cycles of compression/decompression is one way to control the amount of bubbles and the range of sizes of the gas bubbles.
[0042] Yet another way to create bubbles from gas dissolved in a liquid is to raise the temperature of the liquid, e.g., using a heat exchange system. The amount of temperature shift and/or the rate of temperature change is determinative of the size (range of sizes) of the bubbles.
[0043] As yet another alternative, acoustic energy may be used to create bubbles in a gasified liquid. In such an approach, bubbles are formed as a result of acoustic energy waves (which are pressure waves) causing compression/decompression cycles in the liquid.
[0044] Instead of forming bubbles out of a dissolved gas, direct injection of gas bubbles in a liquid may be used in methods for generating and controlling transient cavitation. In an example of such an approach, a bubbler system, a capillary, a nozzle, etc. is used to inject gas bubbles into a liquid. Alternatively, a membrane contactor with a dedicated pore size may be used, where the membrane separates the liquid from the injected gas.
[0045] In general, the design of apparatus used to implement such methods, the amount of gas present in a liquid, the decompression rate, the amount and/or rate of temperature shift, the presence of surface-active agents (e.g. surfactants), etc. affects the final size of the bubbles present in the liquid. The smallest bubbles will disappear again as dissolved gas and the bigger bubbles will grow. The size of a bubble is determinative of whether a bubble grows or disappears (dissolves). This size is dependent on the vapor pressure in the liquid, the ambient pressure of the liquid and the surface tension of the liquid.
[0046] Any number of techniques may be used to measure bubble sizes. These techniques include light-scattering and sound dispersion.
[0047] In one light-scattering approach, a laser beam is directed through a cell in which a liquid containing gas bubbles is flowing in a continuous way, generally perpendicular to the laser beam. Bubbles in the liquid which cross the path of the laser beam cause light-scattering, which is then detected by a photodiode connected to an oscilloscope. The laser beam itself is blocked by a beam stopper after crossing the cell. The intensity of the light-scattering signal is a measure for the bubble size and is calibrated by means of latex sphere equivalent sizes. This approach may be applied in the presence of an acoustic field.
[0048] In one sound-dispersion method, an acoustic transmitter sends an acoustic signal towards a receiver through a fluid medium (liquid) containing gas bubbles. The bubbles present in the fluid influence attenuation and a group velocity of the acoustic signal. These two parameters can then be used to determine a measure of gas bubble size(s) and a number of bubbles. In comparison with the light-scattering method described above, this sound-dispersion method may not be applicable in the presence of an acoustic field due to influences of the acoustic field on the acoustic signal for measuring bubble size(s) and number.
[0049] In an example method, the created gas bubbles (or at least a portion of the bubbles) are subjected to an acoustic field with a given acoustic pressure and a given frequency. The applied acoustic field causes particular bubble activity: growth, pulsation and/or collapse of bubbles. All bubbles in the acoustic field are considered active but not all of them may collapse. For instance, as was previously discussed, only bubbles with a particular distribution of bubble size will collapse so as to result in transient cavitation. This phenomenon is described by the Rayleigh-Plesset model, which is known to those working in this area. The following equation describes the adiabatic collapse of a gas bubble in a liquid:
ρ ( R R ¨ + 3 2 R . 2 ) = P g ( R ) - P 0 - P a ( t ) + R c ⅆ ⅆ t [ P g ( R ) - P a ( t ) ] - 4 η R . R - 2 σ R
wherein R is the bubble radius, ρ is the liquid density, P g is the vapor pressure, P 0 is the ambient hydrostatic pressure, P a is the time dependent driving pressure, c is the speed of the acoustic waves in the liquid, η is the liquid viscosity and σ is the liquid surface tension. The driving pressure is dependent on the frequency and intensity (power) of the acoustic field.
[0050] Generally, for particle removal applications (such as cleaning of semiconductor substrates), collapsing bubbles cause micro-streaming and shockwaves that result in the creation of a drag force over particles that are present on the surface. If the drag force overcomes the VanderWaals and electrostatic forces between the particle and the surface being cleaned, those particles have a high probability of being removed. Thus, in order to obtain a achieve a more efficient cleaning, it is desirable to increase the amount of micro-streaming and/or shockwaves in a liquid that impinge on the surface being cleaned with the liquid. Such an increase in micro-streamimg and/or shockwaves may be achieved by increasing the number of gas bubbles that collapse in the liquid near the surface being cleaned (e.g., a semiconductor substrate).
[0051] Theoretical calculations and experimental data showed that only a specific range of bubble sizes collapse in a corresponding specific acoustic field. FIG. 4 is a graph which illustrates that bubbles smaller than a first threshold bubble size or bigger than a second threshold bubble size do not tend to collapse in an acoustic field with a particular intensity and a particular frequency, in this case 1 MHz.
[0052] FIG. 5 is a graph that illustrates that an upper-pressure limit (Pm) and an upper-temperature limit (Tm) during bubble collapse is dependent on a frequency of an applied acoustic field. Thus, by generating an appropriate bubble size (or range of sizes) for a particular acoustic field, transient cavitation may be controlled. For cleaning applications, the process conditions may be adjusted in order to obtain substantially uniform cleaning (e.g., particle removal) and reduce the potential for damage to a surface (e.g., a semiconductor substrate) being cleaned by controlling violently collapsing bubbles.
[0053] In methods for generating and controlling transient cavitation, a range of gas bubble sizes in the region where an acoustic field is provided and the parameters of the acoustic field are established in correspondence with one another, so as to result in substantially uniform transient cavitation occurring in that region. Accordingly, if the useful range of gas bubble sizes is limited (such as due to the technique used to create bubbles), the parameters of the acoustic field may be adjusted to obtain the desired transient cavitation. Likewise, if there are limitations on varying the parameters of the applied acoustic field, the range and distribution of bubble sizes may be adjusted to achieve the desired transient cavitation.
[0054] One way to achieve a desired level of uniformity of transient cavitation in a liquid is by adjusting the range of bubble sizes that are present at the bottom of a tank containing the liquid, when an acoustic field is applied near the surface of the liquid in the tank. This may be achieved in a number of ways. For instance, the range of bubble sizes may be adjusted by adjusting the design or setting of a valve, an orifice, a membrane contactor, etc. used to introduce gas into the liquid. As the bubbles will grow as they rise in the tank, this fact should be considered when adjusting the range of bubble sizes at the bottom of the tank (e.g., when the bubbles are created) so that the bubbles will have the desired range of sizes when entering the acoustic field. In addition the initial size of the generated bubbles, the depth at which the bubbles are generated, the depth of the tank and the position of the acoustic field may be varied. The liquid flow speed and orientation is another parameter that can be varied and has an influence on the size and distribution of the gas bubbles in the liquid.
[0055] Compression and decompression cycles may also be used for adjusting the range of bubble sizes, as well as for generating bubbles in a gasified liquid. Increasing pressure results in a corresponding decrease in bubble size, while decreasing pressure results in a corresponding increase in bubble size. Furthermore, gradual decompression (e.g., releasing pressure in the tank in several steps) may be used to generate bubbles at different depths in the tank in order to achieve a desired bubble distribution.
[0056] Another approach for adjusting the range of bubble sizes is to vary the range of generated bubble sizes over time. In such an approach, the period of time during which smaller bubbles are generated will result in bubbles of the desired range of sizes being present at a shallower depth in the liquid. Comparatively, the period of time during which larger bubbles are generated will result in bubbles of the desired range of sizes being present at deeper depths in the liquid. Because the bubbles grow as they rise, a uniform bubble distribution through a larger range of depths is obtained in this way.
[0057] Alternatively or in combination with other approaches, the gas that is introduced (e.g., dissolved) in the liquid may be varied as a factor in controlling the range of sizes of bubbles. Different gases with different material properties allow for influencing the final bubble size distribution as well. For example, N 2 gas has a lower saturation level in pure water than O 2 gas. Thus, the use of N 2 will more readily result in gas bubbles being formed when compared to O 2 . Therefore, N 2 gas may be introduced into the liquids at a shallower depth than O 2 and produce a region in the liquid where, as the bubbles rise in the tank, the bubble size is approximately the same for both bubbles of both N 2 and O 2 gasses. Of course, more than two types of gasses can be used for further controlling the range of bubble sizes and/or the distribution of bubbles in a liquid.
[0058] Yet another technique that may be used for adjusting the range of sizes of bubbles and the distribution of bubbles is the use of surfactants for lowering the surface tension of the liquid in which the bubbles are being produced. Such a reduction in surface tension will result in a corresponding increase in bubble size.
[0059] Generation of an acoustic field as part of a method for controlling transient cavitation may likewise be accomplished using any number of possible approaches. For example, an acoustic field may be generated using multiple transducers that generate acoustic signals with different frequencies. The acoustic field produced in a liquid contained in a tank using such an approach may be termed a multiple frequency field. Using such an approach, a broader range of bubble sizes can be controlled with respect to cavitation. For example, a megasonic field of 1 MHz affects bigger bubbles than a field of 2 MHz. Therefore, if a megasonic field of 1 MHz is applied at a shallower depth than a 2 MHz field, a broader range of bubble sizes will be affected through the depth of the tank, resulting in more uniform transient cavitation at a desired depth in the tank.
[0060] Furthermore, yet an additional acoustic field (having one or more frequencies) may be applied at depth below a depth where a desired range of bubble sizes is to be achieved. In such an approach, the additional acoustic field (with appropriate parameters) is used to cause a range (or ranges) of bubble sizes that are undesirable to collapse before entering the region where the final range of bubble sizes is desired.
[0061] FIG. 6 is a schematic illustration of an apparatus that may be used to implement at least some of the approaches described herein. For the apparatus illustrated in FIG. 6 , a first acoustic field is generated at the bottom of a liquid tank. The first acoustic field is generated by a first plurality of transducers operating at a common first frequency to create bubbles with a particular range of sizes. At a shallower depth in the tank, a second plurality of transducers operating at a second common frequency is positioned such that it causes grown bubbles to collapse. For a fixed liquid flow and a fixed distance (d) between a given single transducer of the first plurality of transducers at the bottom of the tank and a corresponding given single transducer of the second plurality of transducers at shallower depth, substantially every bubble generated at the given single transducer of the first plurality of transducers will grow by substantially the same amount and will collapse when subjected to the acoustic field of the corresponding given single transducer of the second plurality of transducers.
[0062] FIG. 7 is a flowchart that illustrates an example process flow for generating and controlling transient cavitation. In the process of FIG. 7 , characteristics of an acoustic field are selected, followed by selection of a range of bubble sizes based on the Rayleigh-Plesset model. As was discussed above, these operations may also be done in reverse order.
[0063] In the method of FIG. 7 , the selected range of bubble sizes is created by dissolving gas in the liquid and creating bubbles or, alternatively, by direct injection of gas bubbles in the liquid. When the selected acoustic field is generated, the liquid with bubbles in the selected range of bubble sizes is subjected to it. After creating or injecting gas bubbles, the range of bubble sizes is measured by one of the measurement techniques described above. The results of the measurement are used to control the range and creation/injection of bubbles and/or the characteristics and creation of the acoustic field. In this way a feed-back loop process is created for controlling transient cavitation in the liquid.
[0064] The methods and apparatus described herein may also be used in applications where the acoustic field is not generated in a tank containing a liquid. For example, in semiconductor applications, several batch and single wafer cleaning tools are known where a cleaning solution is applied on a rotating wafer and an acoustic field is communicated to the cleaning solution via the wafer. Also single wafer cleaning tools are known where the cleaning solution is subjected to an acoustic field as the fluid is being supplied (e.g., as it impinges on the surface of a wafer) by means of a megasonic or ultrasonic spray nozzle. Such a spray nozzle can be constructed the fashion shown in FIG. 8 . For the nozzle of FIG. 8 , a de-ionized water (DIW) supply 2 and a gas+DIW supply 3 are communicated through the nozzle. A transducer 4 is mounted in the tip of the nozzle, surrounding the gas+DIW supply 3 . In this set-up, a mixture of DIW and gas, containing gas bubbles with a selected range of bubble sizes, is generated before entering the DIW+gas supply 3 .
[0065] Two other possible fields of application for the approaches described herein are sonochemistry and ultrasound diagnostics, though other applications exist. For sonochemistry, such methods may be used to inject energy from transient cavitation in a controlled way in order to obtain a uniform catalytic effect resulting in a uniform chemical reaction speed. For ultrasound diagnostics, bubble sizes and acoustic field(s) can be modified to enhance scattering of ultrasound by the bubbles so as to result in better image contrast.
EXAMPLES
Example 1
[0066] By means of the Young formula, which is based on the Rayleigh-Plesset model, the resonant radius of a bubble at a particular frequency can be calculated:
ω r 2 = ( 3 γ P 0 ρ R 0 2 )
[0067] If the frequency (φ r )=1.8 MHz and ω r =2πφ r , the adiabatic constant (γ) for oxygen=1.4, the density (ρ) for DIW=1000 kg/m 3 and the hydrostatic pressure (P 0 ) at 0.25 m depth=103800 Pascal, then the resonant radius is 1.85 μm. This means that in a 1.8 MHz acoustic field, even at very low acoustic pressure (e.g. 0.1 W/cm 2 ), bubbles with a radius of 1.85 μm will collapse. At higher acoustic pressures (e.g. 10 W/cm 2 ), a broader range of bubbles sizes close to the resonant radius will collapse as well.
[0068] In a particular Techsonic wafer cleaning tank, an acoustic field of 1.8 MHz and 5 W/cm 2 was generated. The water and gas supply system of the tank, working at 2.5 bar overpressure and containing 18 ppm oxygen after passing a Mykrolis Phasor 2 gasification unit, operated at a flow of 8 SLM with the tank filled a depth 0.25 m from the bottom. A decompression step (to 103800 Pascal) was performed at the inlet of the tank. This decompression step resulted in a bubble size distribution close to the resonant radius at the bottom of the tank. The results of Particle Removal Efficiency (PRE) for 80 nm SiO 2 particles on a silicon wafer, measured by the haze channel of the SP1DLS from KLA-Tencor is shown in FIG. 9 . At the lower part of the wafer, PRE is about 99%, where at the top part, PRE is only 1%.
[0069] When supplying water at the bottom of the tank containing only 10 ppm of oxygen, bubbles with a size below the resonant radius are generated. As they rise in the tank, those bubbles grow in size due to changes in hydrostatic pressure and rectified diffusion until they reach a bubble size distribution close to the resonant radius. In this case, the results of PRE are given in FIG. 10 . At the lower part of the wafer PRE is only 1% where at the top part, PRE is about 99%.
Example 2
[0070] A set of silicon substrates contaminated with 34 nm SiO 2 -particles was used to evaluate the cleaning performance of a single wafer megasonic cleaning tool. The formation of bubbles to achieve (generate) transient cavitation, was done using a chemical supply system prior to applying a megasonic field. A backpressure regulator was used to realize a pressure drop, which created a controlled over-saturation of a specific gas, in this case argon. This process resulted in a specific bubble distribution. To obtain this bubble distribution, ultra pure water was gasified at high pressure (P water =2.6 bar). The amount of argon added was chosen such that the liquid was under-saturated at the 2.6 bar level (no bubbles were present), but 20% over-saturated after the pressure drop (P water ˜1 bar). Due to the over-saturation, the excess amount of argon created a typical bubble distribution in the supply system, which is shown in FIG. 11 . The generated bubble distribution was monitored by an in-line light scattering tool, the tool being designed to measure bubbles larger than 2 μm.
[0071] The ultra pure water containing the argon bubbles was the subjected to the megasonic field. The activity of the bubbles in the area of application of the megasonic field resulted (after 1 minute of subjection to the megasonic field at 125 W input power) in a PRE on the order of 80% for 34 nm SiO 2 -particles as compared to 0% when no gases were added and 40% when the level of saturation was below 100%.
CONCLUSION
[0072] While a number of aspects and embodiments have been discussed above, it will be appreciated that various modifications, permutations, additions and/or sub-combinations of these aspects and embodiments are possible. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and/or sub-combinations as are within their true spirit and scope. | The invention relates to a method for creating transient cavitation comprising the steps of creating gas bubbles having a range of bubble sizes in a liquid, creating an acoustic field and subjecting the liquid to the acoustic field, characterized in that the range of bubble sizes and/or the characteristics of the acoustic field are selected to tune them to each other, thereby controlling transient cavitation in the selected range of bubble sizes. It also relates to an apparatus suitable for performing the method according to the invention. | 8 |
CROSS REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of U.S. application Ser. No. 10/975,780, filed Oct. 28, 2004. The entire teachings of the above application(s) are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] With the proliferation of software products and services, attempts have been made to codify and/or standardize the designing of software and software architecture. Examples include:
[0003] The Booch Method and Modeling Language (see “Object Oriented Analysis and Design” by Grady Booch);
[0004] James Rumbaugh and associates' Object Modeling Technique (OMT);
[0005] the Object Oriented Software Engineering (OOSE) method by Ivar Jacobson; and
[0006] the Unified Modeling Language (UML) which combines the foregoing and industry best practices.
[0007] The UML is a visual modeling language (with formal syntax and semantics) for communicating a model or conceptionalization. Thus the modeling language specification specifies modeling elements, notation and usage guidelines and not order of activities, specification of artifacts, repository interface, storage, run-time behavior and so forth. In general, at the modeling level a “problem” is posed in terms of a customer's needs and requirements and may be referred to as the business problem system. The software designer develops a “solution” software product and or service that addresses the problem. The UML syntax enables software designers to express (specify and document) the subject problems and solutions in a standardized manner, while the UML semantics enable knowledge about the subject system to be captured and leveraged during the problem solving phase. See “UML in a Nutshell” by Simon Si Alhir, published by O'Reilly & Associates, September 1998. As such, the UML enables the sharing of information (including prior solution portions) and extension (without reimplementation) of core object oriented concepts (analysis and design) during the iterative problem-solving process for designing software products.
[0008] A property in UML 2.0 can be marked as being a derived union. The collection of values denoted by the property in some context is derived as the strict union (superset) of all the values denoted, in that context, by properties that subset it. A derived property is identified as a union with a union constraint on the supersetting property.
[0009] The Rose model for UML 2.0 contains many attributes and associations that are constrained to be derived unions. There are, however, no known mechanisms for generating Java code that enforces these constraints. The Eclipse Modeling Framework (EMF) can be used to generate Java code from a Rose model, but provides no automated support for processing derived unions. Indeed, since all such properties are derived, the EMF discards these properties altogether. Even if these properties were retained, the constraint information is discarded by EMF during code generation.
SUMMARY OF THE INVENTION
[0010] The present invention overcomes the above limitation and provides a mechanism for generating target code (e.g. Java) that enforces derived union constraints.
[0011] In one embodiment, a computer method for enforcing derived union constraints includes the steps of:
[0012] providing a model element having one or more derived union properties;
[0013] tracking derived union constraints from the one or more derived union properties of the model element; and
[0014] interpreting the tracked derived union constraints and generating therefrom an implementation that enforces the derived union constraint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0016] FIG. 1 is a schematic illustration of a non-list derived union property “namespace”.
[0017] FIG. 2 is a schematic illustration of the derived union of FIG. 1 subsetted by the “class” property.
[0018] FIG. 3 is a schematic illustration of a list derived union property “ownedElement”.
[0019] FIG. 4 is a schematic illustration of the derived union of FIG. 3 subsetted by the properties “ownedMember”, “elementImport” and “packageImport”.
[0020] FIG. 5 is a block diagram of a preferred embodiment.
[0021] FIG. 6 is a schematic view of a computer environment in which the principles of the present invention may be implemented.
[0022] FIG. 7 is a block diagram of the internal structure of a computer from the FIG. 6 computer environment.
[0023] FIG. 8 is a schematic illustration of computer systems implementing methods of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A description of preferred embodiments of the invention follows.
[0025] Since it would be desirable to generate code that in some way reflects derived union constraints, the present invention records information about derived union properties as constraints. The present invention records this information in the form of annotations on a code generation model. Such properties are made non-changeable, transient, volatile, and non-containment, and corresponding overriding operations are created on classes that contain subsetting properties for the derived unions. Java templates are used to automatically generate code for these operations based on the annotations. The generated comments for the methods associated with these operations indicate for which properties the operation represents a superset, and code is generated for the bodies of these methods, as described below.
[0026] There are a couple of scenarios to consider with respect to derived unions. First, consider the case of a non-list derived union. Shown in FIG. 1 is an example.
[0027] There is shown a class called “NamedElement” 15 with two properties—“name” and “/qualifiedName”. The latter (/qualifiedName) has a derived value which is computed on demand (in real time), as indicated by the forward slash prefix.
[0028] A Namespace object 13 is a type of NamedElement 15 (i.e., is an instance of the class 15 ). The relationship or associations between Namespace 13 and NamedElement 15 model elements (objects) are indicated at 17 and include certain properties 19 a,b of Namespace 13 . Each of these properties 19 is a derived union of a respective set of values indicated between curly brackets. The constraint label (or flag) ‘union’ is also indicated in the curly brackets.
[0029] The “ 0 .. 1 ” in FIG. 1 indicates a multiplicity 27 on the relationship 17 . So the indicated number (multiplicity 27 ) of the Namespace objects 13 can be related to a given NamedElement object 15 .
[0030] Similarly cardinality 29 of the relationship 17 is represented by an asterisk and has a value indicating the number of NamedElement objects 15 related to a given Namespace 13 instance.
[0031] The derived unions (i.e., sets of values) and valid values for multiplicity 27 (and cardinality 29 ) of a relationship 17 are constraints on that relationship (association between objects 13 , 15 ). Further, if Namespace object 13 is related to other instances/objects, then these other instances/objects inherit these constraints.
[0032] In FIG. 2 , property “namespace” 19 b of FIG. 1 is subsetted by the “class” property 21 in the relationship between Property object 23 and Class object 25 . In this context, a subset of the values of namespace 19 b (defined in FIG. 1 as a derived union) is used as the values of class property 21 .
[0033] In the present invention, contents of the curly brackets (i.e., the derived union constraints) are traversed and maintained as annotations on a subject model element instead of being parsed out as in the prior art. As illustrated in FIG. 5 , in the preferred embodiment, a subject Rose model is used and is the basis for a code generation model 61 of interest, i.e., the software product model being designed. The Rose model for 61 provides support for initially capturing the constraints denoted in curly brackets. The present invention records in the form of annotations 59 in respective parts of the code generation model 61 constraint information for each derived union property (generally 57 ) of respective model elements 67 . Next the present invention employs EMF to generate JAVA code (or the like) from the annotated code generation model 61 , 59 in a manner that supports processing derived unions. In particular, the invention EMF processing 63 interprets derived union constraint information and keeps track of derived union (originally curly bracketed) items using the annotation entries 59 . The resulting EMF 63 output is an API (e.g., in an object oriented programming language) 65 that enforces derived union constraints.
[0034] In the case of subsetted properties, corresponding overriding operations are created on classes that contain subsetting properties for the derived unions. Java templates are used to automatically generate code for these operations based on the annotations 59 . The generated comments for the methods associated with these operations indicate for which properties the operation represents a superset, and code is generated for the bodies of these methods.
[0035] For purposes of illustration and not limitation, the present invention generates code for the getNamespace( ) operation on the PropertyImpl class (created to override the implementation inherited from its parent) that resembles the following:
[0000]
if (null != getClass_( ) ) {
return (Namespace) getClass_( );
}
if (null != getOwningAssociation( ) ) {
return (Namespace) getOwningAssociation( );
}
if (null != getDatatype( ) ) {
return (Namespace) getDatatype( );
}
return super.getNamespace( );
[0036] Now consider the case of a list derived union. For example, the ownedElement property 31 of the Element class 35 is a derived union, as shown in FIG. 3 . That is, the property 31 name is preceded with a slash (“/”), and indicated between curly brackets is the ‘union’ constraint 33 . Further, the “ownedElement” 31 derived union is subsetted by, for example, the ownedMember (also a derived union), elementImport, and packageImport properties 43 , 45 , 47 of the Namespace class 41 , shown in the class diagram of FIG. 4 . Thus objects of the Namespace class 41 inherit from the properties “namespace” 39 (also a derived union) and “ownedMember” 43 , the respective derived union and subsets constraints. The “ownedElement” 31 part of these constraints includes its own derived union constraint 33 as discussed in FIG. 3 above and as used here is a nested derived union 33 .
[0037] Similarly, property elementImport 45 and property packageImport 47 each has a nested derived union constraint due to subsetted ownedElement 31 .
[0038] The present invention thus not only maintains annotations 59 ( FIG. 5 ) of the contents between curly brackets for derived unions 57 but also includes any nested derived union data. Such a superset (multiple level inclusive) list of annotations 59 represents the derived union constraints of interest. The preferred embodiment employs EMF 63 to interpret these derived union constraints (including nested ones) from recorded annotation entries 59 and generate a corresponding API 65 that enforces them. An example code generation follows.
[0039] The preferred embodiment generates code for the getOwnedElement( ) operation on the NamespaceImpl class (created to override the implementation inherited from its parent) that resembles the following:
[0000]
Set union = new HashSet( );
union.addAll(super.getOwnedElement( ) );
union.addAll(getOwnedMember( ));
union.addAll(getElementImport( ) );
union.addAll(getPackageImport( ) );
return new EcoreEList.UnmodifiableEList(this,
Uml2Package.eINSTANCE.getElement_OwnedElement( ),
union.size( ), union.toArray( ) );
[0040] FIG. 6 illustrates an example computer environment in which the present invention operates. Client computer(s) 50 and server computer(s) 60 provide processing, storage, and input/output devices executing application programs and the like. Client computer(s) 50 can also be linked through communications network 70 to other computing devices, including other client computer(s) 50 and server computer(s) 60 . Communications network 70 can be part of the Internet, a worldwide collection of computers, networks, and gateways that currently use the TCP/IP suite of protocols to communicate with one another. The Internet provides a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational, and other computer networks, that route data and messages. In another embodiment of the present invention, the methods are implemented on a stand-alone computer. In either network or standalone, the invention output software design and models (API's) are sharable and reusable among users.
[0041] FIG. 7 is a diagram of the internal structure of a computer (e.g., client computer(s) 50 or server computers 60 ) in the computer system of FIG. 6 . Each computer contains system bus 79 , where a bus is a set of hardware lines used for data transfer among the components of a computer. Bus 79 is essentially a shared conduit that connects different elements of a computer system (e.g., processor, disk storage, memory, input/output ports, network ports, etc.) that enables the transfer of information between the elements. Attached to system bus 79 is I/O device interface 82 for connecting various input and output devices (e.g., displays, printers, speakers, etc.) to the computer. Network interface 86 allows the computer to connect to various other devices attached to a network (e.g., network 70 of FIG. 6 ). Memory 90 provides volatile storage for computer software instructions used to implement an embodiment of the present invention (e.g., EMF code and Rose models of subject Program Routines 92 and Data 94 ). Disk storage 95 provides non-volatile storage for computer software instructions and data used to implement an embodiment of the present invention. Central processor unit 84 is also attached to system bus 79 and provides for the execution of computer instructions.
[0042] Referring now to FIG. 8 illustrated is another computer system 10 embodying the present invention techniques mentioned above. Generally, computer system 10 includes digital processor 12 in which subject modeling language and EMF code 20 are utilized. Input means 14 provides user commands, selections (generally communication) to computer system 10 .
[0043] Responsive to input means 14 is user interface 22 . User interface 22 receives user input data from input means 14 and provides input data for processing and manipulation at 20 . The methods of the invention are implemented at 20 for designing Application Program Interfaces that enforce derived union constraints in JAVA, UML, EMF and the like which are output at 16 . Output 16 may be a display monitor, printer or other computer.
[0044] In one embodiment, computer program product 80 , including a computer readable medium (e.g., a removable storage medium such as one or more DVD-ROM's, CD-ROM's, diskettes, tapes, etc.) provides at least a portion of the software instructions at 20 and/or user interface 22 . Computer program product 80 can be installed by any suitable software installation procedure, as is well known in the art. In another embodiment, at least a portion of the software instructions may also be downloaded over a wireless connection. Computer program propagated signal product 83 embodied on a propagated signal on a propagation medium (e.g., a radio wave, an infrared wave, a laser wave, a sound wave, or an electrical wave propagated over a global network such as the Internet, or other network(s)) provides at least a portion of the software instructions at 20 and/or user interface 22 .
[0045] In alternate embodiments, the propagated signal is an analog carrier wave or digital signal carried on the propagated medium. For example, the propagated signal may be a digitized signal propagated over a global network (e.g., the Internet), a telecommunications network, or other network. In one embodiment, the propagated signal is a signal that is transmitted over the propagation medium over a period of time, such as the instructions for a software application sent in packets over a network over a period of milliseconds, seconds, minutes, or longer. In another embodiment, the computer readable medium of computer program product 80 is a propagation medium that the computer system 10 may receive and read, such as by receiving the propagation medium and identifying a propagated signal embodied in the propagation medium, as described above for computer program propagated signal product 83 .
[0046] Generally speaking, the term “carrier medium” or transient carrier encompasses the foregoing transient signals, propagated signals/medium, storage medium and the like.
[0047] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
[0048] For example, the model interpreter 63 may be implemented in UML, EMF and other modeling languages. The resulting API code (generated implementation) 65 may be in Java, UML, EMF, XML and the like. | A computer method and system preserves derived union constraints and enforces the same in generated target code. The method includes (a) providing a model element having one or more derived union properties, (b) tracking derived union constraints from the derived union properties of the model element, and (c) interpreting the tracked derived union constraints and generating therefrom an implementation that enforces the derived union constraint. Tracking may be by annotating the model element accordingly. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to back and front spotfacing and counterboring tools, and more particularly to an improved such tool having a fluid pressure actuated tool bit which is automatically pivoted between operative and inoperative positions. Moreover, this invention relates to a novel method of utilizing a pressurized coolant fluid for automatically actuating the tool bit of an improved tool of the type disclosed herein.
There are currently available in the marketplace a variety of spotfacing and counterboring tools having tool bits which are pivotal relative to the tool body between inoperative positions in which they are housed within recesses within the tool body, and operative positions in which they project outwardly from the tool bodies into work cutting positions. In my pending U.S. patent application Ser. No. 08/775,576 this movement of a tool bit between operative and inoperative positions is effected by a fly wheel which is carried by the tool body; and in my U.S. patent application Ser. No. 08/953,453, this operation is effected by a spring-loaded actuating ring which is rotatably briefly relative to the supporting tool body thereby to effect movement of the associated tool bit each time the rotation of the tool body is reversed. Also as noted in my application Ser. No. 08/953,453, there are several U.S. patents which disclose tools in which the associated cutter elements are moved between operative and inoperative positions by virtue of engagement of a thrust element on the tool with the surface of the workpiece that is to be machined.
In addition to the above-noted tools there also is a U.S. patent Ser. No. 3,572,182, which teaches the manipulation of the cutter blade of a cutting tool by use of a supply of compressed air or hydraulic fluid that is operatively connected to the cutter to manipulate its associated cutter blade.
Among the numerous problems associated with such prior art devices is the fact that much of the movement of the cutter bit relative to the associated cutter body relies upon the rotation of the tool body to produce the desired manipulation of the cutter bit or blade. Thus, any failure of any of the parts that mechanically transmit the rotation of the tool body to the mechanism which manipulates the cutter bit, will result in unsatisfactory manipulation of the cutter bit. Although this is a lesser problem in connection with a cutter bit of the type disclosed by the above-noted U.S. Pat. No. 3,572,182, such fluid pressure operated devices, nevertheless, are rather expensive to construct and install, and require separate valving means used exclusively for controlling the flow of air pressure to and from the associated tool.
It is an object of this invention, therefore, to provide an improved fluid actuated spotfacing and counterboring tool which eliminates the need for employing as part of the tool separate valving means for controlling the flow of operating fluid to and from the tool.
Another object of this invention is to provide an improved spotfacing and counterboring tool of the type described which utilizes a fluid under pressure for moving an associated tool bit from an inoperative to an operative position, and which relies solely upon a spring mechanism for returning the tool bit to its inoperative position.
A further object of this invention is to provide a novel method of utilizing existing pressure operated coolant systems for effecting manipulation of the associated tool bit of an improved tool of the type described herein.
Still other objects of this invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
A cylindrical tool holder has therein an axially reciprocable operating rod drivingly connected at one end to a cutter tool bit, which is mounted in a recess in one end of the holder for pivotal movement by the operating rod between an inactive position within the recess, and an active position in which it projects radially from the holder and out of the recess for engagement with a workpiece. The opposite end of the holder is releasably secured in one end of an axial bore in a tool driver, the opposite end of which has secured therein a retention knob that is used for mounting the cutter in a drill press, or the like. The retention knob has therein an axial bore for supplying coolant under pressure through the bore in the driver, and an axial bore in the tool holder to the recess in which the tool bit is mounted, thereby to supply coolant for the tool bit when the latter is in use.
The interconnected ends of the tool holder and tool driver are surrounded by an annular actuator having at one end a reduced-diameter bore that is axially slidable on the driver, and which at its opposite end is drivingly connected to the operating rod, so that the axial movement of the actuator on the driver imparts axial movement to the tool bit operating rod. A stationary valve ring which surrounds the driver within the actuator cooperates with the reduced-diameter end of the actuator to form an expansion chamber which communicates through a plurality of radial ports in the driver with its bore. A plurality of compression springs interposed between the tool bit holder and the actuator normally retain the actuator in a first limit position in which the operating rod causes the tool bit to be retained with the recess in the holder. However, when coolant fluid under pressure is connected to the bore in the retention knob, the fluid flows through the radial ports of the driver and into the expansion chamber to cause the actuator to be shifted against the resistance of the compression springs to a second limit position in which the operating rod is drawn in the direction to cause the tool bit to be swung outwardly to its operative position.
THE DRAWINGS
FIG. 1 is an axial section view through the center of a fluid actuated spotfacing and counterboring tool made according to one embodiment of this invention, the associated fluid actuated piston being shown in its advanced position in which it has caused the associated tool bit to be retracted into an inoperative position within a recess in the cylindrical tool body;
FIG. 2 is a view similar to FIG. 1, but illustrating the fluid actuated piston in its retracted position in which it has caused the associated tool bit to be swung out of the associated recess in the tool body and into an operative or cutting position;
FIG. 3 is a sectional view taken generally along the line 3--3 in FIG. 1 looking in the direction of the arrows;
FIG. 4 is a fragmentary, axial sectional view through a tool made according to the second embodiment of this invention, the tool bit operating piston being shown in its advanced position; and
FIG. 5 is a fragmentary axial sectional view of the tool shown in FIG. 4, but with the fluid operating piston being shown in its retracted or tool bit operating position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings by numerals of reference, and first to the embodiment shown in FIGS. 1 to 3, 20 denotes generally an automatic fluid actuated spotfacing and counterboring tool having at one end thereof (the right end thereof in FIGS. 1 and 2) a driver body 22, which is circular in cross section, and which has therethrough an axially extending bore 23. For a substantial portion of its axial length driver 22 has formed on one end thereof a cylindrically shaped shank section 24, which terminates at its inner end at one side of an integral, circumferential shoulder 25 that is formed on body 22 intermediate its ends, and which forms no part of this invention. From the other side of shoulder 25 the outer peripheral surface of holder 22 tapers gradually to the right end of the holder as shown in FIGS. 1 and 2, and terminates at a circumferential shoulder 26 which is formed on a conventionally shaped retention knob 27 that is threaded at one end thereof into one end of bore 23. Knob 27, which is utilized in a conventional manner to connect tool 20 to the driving spindle of a drill press, or the like, has therethrough an axial bore 28 which communicates with the bore 23 in the tool body 22.
Projecting coaxially from the end of the tool body 22 remote from the retention knob 27 is an elongate, cylindrically shaped tool bit holder 31 having therethrough an elongate, axial bore 32. At one end thereof (the right end as shown in FIGS. 1 and 2) holder 31 has a slightly reduced diameter shank portion 33, which is secured by a lock screw 34 coaxially in a counterbore in the end of bore 23 remote from the knob 27. Screw 34 is threaded through a radial opening in the tool body shank 24 and projects at its inner end into a radial opening which is formed in the tool holder shank section 33 to communicate with a counterbore formed in section 33 coaxially of, and in communication with the bore 32. Tool holder 31 is thus secured to the body section 22 for rotation therewith, as noted hereinafter, and with its bore 32 in communication with the bore 23 in the tool body 22. The inner end of the tool holder shank 33, which lies on a plane extending diametrally of the bore 23, is positioned adjacent a plurality of openings or ports 36, only two of which are shown in FIGS. 1 and 2, which extend radially through the annular wall of shank 24 at equiangularly spaced points about its axis, and with the axes thereof lying in a diametral plane axially spaced slightly from the plane surface on the inner end of shank 33. The bore 23 of the body 22 thus communicates not only with the axial bore 32 in the holder 31, but also through the ports 36 with the exterior of shank 24 at one side of a stationary, ring-shaped piston 37, which is secured coaxially to the outer peripheral surface of shank 24. The opposite side of piston 37 is engaged with a piston retaining ring 38 which is secured in and projects radially from a circumferential recess formed in shank 24 adjacent to the opening containing the screw 34.
The piston 37 is surrounded coaxially by, and has its outer peripheral surface slidably engaged with, the inner peripheral surface of an annular wall which is formed on one end of a cylindrically shaped hydraulic actuator 41. Actuator 41 has at its opposite end (the right end as shown in FIGS. 1 and 2) a reduced-diameter bore having an inner peripheral surface 42 slidably engaged with the outer peripheral surface of shank 24 of the tool body 22. Piston 37 cooperates with the reduced-diameter end of actuator 41 to form between the annular wall of actuator 41, and the outer peripheral surface of shank 24, an expansion chamber 44 which communicates with the ports 36 for a purpose noted hereinafter.
The end of the actuator 41 remote from its reduced-diameter section (the left end thereof as shown in FIGS. 1 and 2) extends over, and is radially spaced coaxially about a slightly enlarged diameter shoulder section 46 which is formed on the holder 31 just rearwardly of the shank section 33 thereof. Surrounding shoulder section 46 for limited axial sliding movement thereon, and secured by a plurality of screws 47 coaxially in the surrounding end of the actuator 41, is an annular actuator disc 48. Also surrounding the shoulder section 46 for limited axial sliding movement thereon, and secured by a plurality of screws 49 to the plane, outer surface of the inner disc 48, is another annular actuator disc 50, which is generally in similar size to, and which registers coaxially with disc 48. All rotational and axial movement of the actuator 41, is thus transmitted to each of the inner and outer annular discs 48 and 50, respectively.
Secured in a circumferential recess formed in the outer periphery of the shoulder section 46 of holder 31 adjacent shank section 33, is a circular retainer ring 52, a portion of which projects radially beyond the outer surface of section 46. At the side thereof remote from the shank 33, ring 52 is engaged with one side of a circular spring backup ring 53, which is positioned in spaced, confronting relation to the plane inner end of the actuator disc 48. Interposed between the inner end of disc 48 and the backup ring 53 are numerous, coiled compression springs 54, each having one end extending through a registering opening 55 in disc 48, and against the inner end of disc 50. Springs 54 normally urge the interconnected actuator discs 48 and 50, and hence the attached actuator 41 into an advanced or tool bit retracting position as shown in FIG. 1. In this position chamber 44 is reduced to its smallest size, since the springs 54 have caused the actuator 41 to be advanced towards the left on the body 22 to a first limit position in which the reduced-diameter end of the actuator 41 is disposed in closely spaced relation to the piston 37. However, as noted hereinafter, the actuator 41 is capable of being shifted axially on the holder 22, toward the right as shown in FIG. 1, until the right end of the actuator 41 engages and is stopped by a circumferential shoulder 56 formed on the holder shank 24 adjacent the shoulder 25 of the holder. As shown in FIG. 2, when the actuator 41 is in this retracted position, the springs 54 have been compressed, and the chamber 44 has become substantially larger compared to the size thereof when the actuator 41 was in its advanced position.
Mounted for limited axial sliding movement in an elongate, blind bore 61, which is formed in the holder 31 in radially spaced, parallel relation to its bore 32, is a tool bit operating rod 62, the purpose of which will be noted hereinafter. The bore 61, which contains rod 62, opens at one end (the left end in FIGS. 1 and 2) on the exterior holder 31, and at its opposite end extends axially and partway through the portion of holder 31 upon which the shoulder section 46 is formed. Adjacent its inner end operating rod 62 extends parallel to, and registers with an axially extending, radial recess 64 formed in the outer peripheral surface of the shoulder section 46 of the holder 31. Mounted for axial sliding movement in the recess 64 over a slot 65, which is formed on the bottom of the recess to register with the inner end of the operating rod 62, is a slider element 66. Secured intermediate its ends in the slider element 66 medially thereof is a dowel pin 67, one end of which extends through slot 65 and is secured to the operating rod 62 adjacent its inner end. At its opposite end dowel pin 67 extends into registering recesses formed in the confronting faces of the discs 48 and 50, and between the confronting ends of two compression springs 68 and 69, opposite ends of which are seated in registering recesses in the confronting surfaces of the discs 48 and 50.
With this construction, any axial movement of the actuator 41 on shank section 24 of the driver body 22 is transmitted via discs 48 and 50 and their springs 68 and 69 to the dowel pin 67. In turn, any such axial movement of pin 67 is transmitted both to the slider element 67 and to the cutter operating rod 62, by virtue of the connection of the lower end of pin 67 to the inner end of rod 62 as shown in FIGS. 1 and 2.
Adjacent its outer or left end as shown in FIGS. 1 and 2, holder 31 has therein an elongate, generally rectangularly shaped tool bit accommodating recess 71. Pivotally mounted adjacent one end thereof on a pivot pin 72, which is secured in holder 31 to extend transversely of the recess 71, is a pivotal cutter element C. In a manner similar to that disclosed in my pending application Ser. No. 08/953,453, operating rod 62 has formed in a portion thereof which opens on one side of the cutter accommodating notch 71, a rack in the form of a plurality of axially spaced, transversely extending notches or recesses 73 in rod 62 (three in the embodiment illustrated). Notches 73 have meshing, driving engagement with a plurality (three in the embodiment illustrated) of angularly-spaced pins 74, which are secured to the end of the cutter C remote from its cutting end so as to extend transversely across an arcuate groove or slot formed in the pivoted end of the cutter C, and for driving engagement by one of the notches 73 in rod 62. As a consequence, when the operating rod 62 is advanced to the cutter retracting position as shown in FIG. 1, the operating rod 62, via the cooperation of its rack section with the pins 74 on the cutter C, cause the cutter to be swung counterclockwise about the axis of the pivot pin 72 and into a retracted or collapsed position in which it is enclosed within the recess 71 in holder 31. Conversely, when the actuator 41 is shifted toward the right relative to the holder 22, or into the position as shown in FIG. 2, the operating rod 62 is retracted slightly from its position as shown in FIG. 1, thereby its rack section causes the cutter C to be swung or pivoted clockwise into its operative position in which it projects outwardly from the recess 71. Regardless of the position in which the cutter C is disposed, it will be noted as illustrated more clearly in FIG. 1, that the axial bore 32 of the holder 31 opens at one end thereof directly on the recess 71 containing the cutter C.
When the cutter 20 is placed in use, its retention knob 27 is operatively connected to a drill press, or the like, as noted above. The bore 28 in the retention knob is then disposed to be connected to a supply of coolant which is maintained under pressure, and which is disposed to be fed through the retention knob via bore 28 to the bore 23 in the holder 22. For the usual purpose, whenever the cutter is placed in use a portion of the coolant entering bore 23 passes through the bore 32 in the tool holder 31, and into the recess 71 to cool the associated cutter C. However, at the same time, since the supply of coolant is typically maintained under a pressure of anywhere from 30 psi. to 1,000 psi., the fluid coolant entering bore 23 also passes through the ports 36 into the chamber 44, thus creating therein a pressure which causes the activator 41 to be shifted axially rearwardly on the shank 24 of the driver body to the position shown in FIG. 2. This movement of actuator 41 causes retraction of the cutter operating rod 62, which therefore causes the cutter to be swung into its operative position as shown in FIG. 2. As long as the pressure of the coolant is maintained in the bore 23, the activator 41 will remain in its retracted or tool actuating position, notwithstanding the fact that a certain amount of the coolant is discharged from bore 32 against the cutter C and the work that it is operating upon.
However, when the cutting operation ceases, the coolant supply is shut off from the bore 28 in the retention knob 27, and since the remaining coolant fluid in the bore 23 is free to be discharged out of the end of the bore 32 into recess 71, the now-compressed springs 54 begin to expand as the pressure in the chamber 44 drops, and in so doing springs 54 urge the actuator 41 toward the left on shank 24 as shown in FIG. 2, and finally into the tool retracting position as shown in FIG. 1. Thus, simply by employing the pressurized coolant rather than a separate pneumatic or pressurized fluid supply, the present invention allows the coolant not only to cool the operating cutter C, but also to effect actuation of an associated tool bit from a retracted to an advanced, operating position. No separate valving system is necessary to supply fluid under pressure to the tool 20 and also to effect return of the fluid under pressure to the source thereof. On the contrary, the fluid flow is one way, and the only valving mechanism that need be employed is the mechanism which has been employed for turning on and off the flow of coolant to the tool 20.
Moreover, by employing the compression springs 68 and 69, which engage diametrally at opposite sides of the dowel pin 67, such springs function as shock absorbers, thus absorbing any shock which might otherwise be transmitted by the pin 67 through rod 62 to the cutter element C. The same shock absorbing effect prolongs the life of the slider element 66, which reciprocates in the recess 64 in the shoulder section 46 of the holder 31. Also, of course, instead of having to rely upon a pressurized fluid to return the actuator 41 from its retracted to its advanced position, the compression springs 54 automatically perform this function when the supply of coolant under pressure has been removed from the retention knob 27.
Still another advantage of this invention is that, if need be, the holder 31 can be removed from the driver body section 22 simply by removing screws 47 which secure disc 48 to the actuator 41, and then removing screw 34, which then permits disc 48 to be removed from actuator 41, and the shank portion 33 of the holder 31 to be withdrawn from the bore in the driver 22. To enable ready access to the screw 34, an opening 75 is formed in the annular wall portion of the actuator 41 to register with screw 34 when the actuator is in its retracted position.
Referring now to FIGS. 4 and 5, wherein like numerals are employed to denote elements similar to those employed in the first embodiment, 80 denotes generally a modified cutter which is generally similar to that shown in FIGS. 1 to 3, except that the coiled compression springs 54, which are utilized to return the actuator 41 to its cutter retracting position, are now mounted externally of actuator 41 rather than internally thereof. More specifically, the springs 54 are engaged at one end against the right, reduced-diameter end of the actuator 41, and at their opposite ends are seated in an annular recess formed in the confronting end of a ring-shaped spring retainer 82, which is secured coaxially to the outer peripheral surface of the shank section 24, and against the external, circumferential shoulder 56 that is formed on the driver body 22. In use, coolant fluid that is supplied under pressure to the bore 23 in the body 22 is used not only to cool the associated cutter element (not illustrated in FIGS. 4 and 5), but also to pass through the ports 36 to chamber 44, thereby causing actuator 41 to be shifted toward the right in FIG. 4 against the resistance of the springs 54, and into the retracted position in which the springs are compressed almost within the annular recess in a confronting end of the retainer ring 82. In this embodiment the actuator rings 48' and 50', which are generally similar to those of rings 48 and 50, respectively, in the first embodiment, are slightly different from the latter because there is no need for them to accommodate ends of the springs 54, nor is there any need to employ a spring retainer ring similar to the ring 53 employed in the first embodiment.
From the foregoing it will be apparent that the present invention provides a relatively simple and inexpensive means for providing a fluid actuated mechanism for effecting the shifting of a tool bit between a retracted, inoperative position, and an extended, operative position in which it projects radially outwardly from the associated tool holder. By relying upon the use of the pressurized coolant fluid, which is used in almost all existing cutter mechanisms, it is possible to eliminate the need for employing special valving mechanisms for supplying some other fluid under pressure for effecting movement of a tool bit from an inoperative to an operative position. Moreover by using springs 54 to return a tool bit and an associated activator element 41 to inoperative positions, additional costs are saved by eliminating the need for a special valving mechanism for returning fluid under pressure from the pressure chamber in a tool from the original supply of pressurized fluid. On the contrary, with the present construction, once the supply of coolant to the tool is interrupted, the pressurized coolant already in bore 23 and chamber 44 of the tool merely discharges through the relatively small diameter coolant hole or bore 32 in the tool holder, and to the exterior of the tool through the recess 71. Springs 54 then function automatically to return the tool bit to its inactive position.
While this invention has been illustrated and described in detail in connection with only certain embodiments thereof, it will be apparent that it is capable of still further modification, and that this application is intended to cover any such modifications as may fall within the scope of one skilled in the art, or within the accompanying claims. | A spotfacing and counterboring tool has therethrough an axial bore communicating at one end with a recess containing a pivotal cutter blade connected to an actuator which is reciprocable on the tool between a first limited position in which it moves the cutter blade to an inoperative position within the recess, and to a second limited position in which it moves the cutter blade to an operative position in which the blade projects out of the recess. An expansion chamber in the tool communicates at one end with the axial bore in the tool, and at its opposite end is closed by the reciprocable actuator, which normally is urged resiliently into its first position, when the tool is not being used, and in which position it places the chamber in its contracted mode. The end of the tool remote from its end containing the cutter blade is disposed to be connected to a machine tool for rotation thereby selectively in opposite directions, and is disposed also to have the adjacent end of its axial bore connected to a supply of coolant fluid under pressure, which flows into the axial bore in the tool, and into the expansion chamber to force the actuator to its second limit position, thereby moving the cutter blade to its operative position, and also causing a portion of the fluid to flow into the recess and cool the now-active cutter blade. | 1 |
FIELD OF THE INVENTION
This invention relates to a container neck and to a closure for a container neck. In particular, the invention relates to the arrangement of a tamper-evident ring for the container neck and closure.
BACKGROUND OF THE INVENTION
Commonly, tamper-evident rings are provided on closures for containers to indicate whether the container has been opened since manufacture, and to act as a guarantee that the contents of the container have not been tampered with. Such rings are often provided on containers for food, drink and medicaments, as well as containers for other items.
A conventional design for a tamper-evident ring is to mount the ring externally of the closure and the container neck, and to secure it to the closure by thin frangible connections. When the closure is removed from the container, the connections become broken to the release the tamper-evident ring. If a purchaser sees that the ring is not intact with the closure, this indicates that the closure has already been removed at least once from the container.
However, such a design of tamper-evident ring is rather unsightly because it gives the closure a bulky appearance. It can also sometimes be difficult to discern without close inspection whether the ring is intact with the closure, or whether the frangible connections have in fact been broken.
SUMMARY OF THE INVENTION
The present invention aims to overcome the above and/or other drawbacks.
In a first aspect, the invention provides an assembly comprising a container neck, a closure adapted to fit the neck, and a tamper-evident ring, the ring being initially substantially concealed by the closure when the closure is fitted to the container neck, the arrangement being such that, in use, after the occasion on which the closure is first removed from the container neck, the tamper-evident ring remains substantially visible on the container neck when the closure is replaced on the neck.
Such an arrangement provides a positive indication once the closure has been removed for the first time. The positive indication is the appearing of the tamper-evident ring itself. The invention appreciates the real essence of a tamper-evident ring, which is, to provide a warning or positive indication if the closure has been removed from the container at least once. It is not necessary to see the tamper-evident ring if the ring is properly intact.
Before the closure has been opened for the first time the tamper-evident ring, being substantially concealed by the closure, also will not give the closure an unsightly appearance.
Preferably, the tamper-evident ring is movably retained on the container neck, and the assembly further comprises releasable holding means for initially holding the tamper-evident ring in a first position in which it is substantially concealed by the closure, the holding means releasing the tamper-evident ring when the closure is first removed from the container, to allow the ring to move into a second position in which it is not substantially concealed by the closure when the closure is replaced on the container neck.
Preferably, the holding means comprises severable connections between the tamper-evident ring and the closure, which connections are severed when the closure is first removed from the container neck.
The tamper-evident ring may be coloured a contrasting colour to the container so that the tamper-evident ring will be clearly visible, and easily discernable at a glance, once the closure has been removed for the first time. For example, the tamper-evident ring may be coloured red as a warning colour.
The portion of the container neck on which the tamper-evident ring sits when in its visible, second position may itself be coloured a colour which contrasts both the rest of the container and the tamper-evident ring. When the tamper-evident ring is in its concealed, first position, this portion of the neck will be visible, and so it may be coloured with a safety colour, such as blue or green, to indicate that the tamper-evident ring arrangement is intact.
Preferably, the tamper-evident ring is slidably retained on a portion of the neck, and is retained thereon. This prevents a person who has maliciously tampered with the container from the tamper-evident ring arrangement is intact.
Preferably, in the second position the tamper-evident ring is separated from the bottom of the closure by a distance at least equalling the axial width of the tamper-evident ring. With such an arrangement, a user can see quite clearly at a glance that the tamper-evident ring is detached from the closure.
Preferably, the closure includes a recess, or a clearance, in which the tamper-evident ring is received when in its concealed, first position. The severable connections are preferably made between an inner wall or walls of the recess, and an edge of the tamper-evident ring. The recess may be defined by a skirt portion of the closure, which covers the tamper-evident ring.
The closure may be of any suitable type, for example, a screw-on closure, or a snap-fit closure. The invention is also particularly suitable for use with a child resistant closure, such as that described in our U.S. patent application Ser. No. 07/796946 entitled "Improvements in Closures For Containers" (claiming priority from our U.K. applications Nos. 9120264.8 and 9122097.0) and the disclosure of which is incorporated herein by reference. The feature which makes the invention suitable for use with such a closure is that the tamper-evident ring does not interfere with the axial or rotational movement of the outer part of the child-resistant closure.
In a closely related aspect, the invention also provides a closure adapted to fit a container neck, the closure comprising a tamper-evident ring and means for substantially concealing the tamper-evident ring from view when in use on a container, until the closure is first removed from the container neck.
Preferably, the concealing means comprises a recess or clearance within the closure in which recess or clearance the tamper-evident ring is substantially received, and holding means for initially holding the tamper-evident ring within the recess or clearance until the closure is removed from the container neck on the first occasion, whereupon the holding means releases the tamper-evident ring so that it will no longer be concealed within the clearance or recess when the closure is replaced.
The concealing means may be in the form of a skirt portion of the closure which covers the tamper-evident ring.
Preferably, the holding means comprises means for forming severable connections with the tamper-evident ring, which connections are intended to be severed on the first occasion that the closure is removed from the container neck.
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 side view of a container with it closure removed;
FIG. 2 is a side view of the container of FIG. 1 with its closure fitted;
FIG. 3 is a sectional view from the side showing a detail of the container neck and closure in FIG. 2; and
FIG. 4 is a sectional view similar to FIG. 3, but showing the tamper-evident ring fitted to a non-child-resistant closure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawings FIGS. 1 to 3 show a container 10 with a neck portion 12 which has a lower waist portion 14 and an upper crown portion 16. The waist portion 14 is defined at its lower end by a shoulder 18 which joins the neck 12 to the body of the container, and at its upper end by an abutment flange 20. The flange 20 has an radially inwardly inclined upper surface 20a and a flat lower abutment surface 20b. The waist portion 14 is adapted to receive a tamper-evident ring as described hereinafter, and the shoulder 18 and the flange 20 together form retaining means for retaining the ring on the waist portion 14 once the ring has been fitted.
The crown portion 16 of the neck 12 has a foil sealing web 22, and carries screw threads 24 adapted to secure a closure means in the form of a screw threaded closure 26 to the container 10.
In this exemplary embodiment, the closure 26 is a child-resistant closure of the type described in our U.S. patent application Ser. No. 07/796946, although it will be appreciated that other types of child-resistant or non-child-resistant closures might be used instead.
The closure 26 comprises an outer closure part 28 and an inner closure part 30. The outer part 28 has an upstanding flange handle 32, and a lower skirt-portion 34. The inner part 30 is coupled internally to the outer part 28 through a child-resistant mechanism (not shown), and carries an inner screw thread (not shown) to match the screw threads 24 of the container neck 12.
The closure 26 is fitted with a tamper-evident ring 36 in the form of an annular member which is received substantially entirely within the recess, or clearance, inside the skirt portion 34 of the closure. Attached to the top of the ring 36 and integral therewith are eight connecting members 38 which taper upwards from a relatively thick lower region into a relatively thin frangible bridge 40 attached to the bottom of the inner part 30 of the closure 26. On the radially inner face of the ring 36, extending between the connecting members 38, are eight triangular section ring retaining clips 42 which are adapted to engage the abutment flange 20 of the container neck 12. Each clip 42 is profiled with a radially inwardly tapered lower ramp surface 42a and a flat upper abutment surface 42b.
Once the desired contents have been placed in the container 10, the closure 26 is screwed on in the normal way, to secure the container in a sealed condition ready for sale. As the closure 26 is screwed down for the first time, the ramp surfaces 42a of the ring retaining clips 42 bear against the tapered surfaces 20a of the flange 20. The ring 36 deforms sufficiently to allow the ramp surfaces 42a to ride easily over the flange 20. When the closure reaches its fully screwed-down position, the ring 36 will be in the a first position in the neck 12 as illustrated at 36a in FIG. 2, fitting immediately under the flange 20.
In this position, the tamper-evident ring 36 is substantially concealed from view by the outer part 28 of the closure 26. In this condition, the assembly indicates that the closure 26 has not been removed since it was first fitted on to the container.
When the closure 26 is unscrewed for the first time, the abutment surfaces 42b of the ring retaining clips 42 bear against the abutment surface 20b of the flange 20 to prevent the ring 36 from being removable from the neck 12 with the closure. The frangible bridges 40 act as severable connections which are severed as the closure 26 is unscrewed, so that the ring 36 becomes detached from the closure 26. Once detached, the ring 36 is free to slide axially down the waist portion 14 of the neck 12, until it rests at a second position against the shoulder 18 as denoted at 36b in FIG. 2.
When the closure is replaced on the neck 12, the lower skirt portion 34 of the closure no longer conceals the tamper-evident ring 36, and the ring remains visible on the neck 12 to indicate that the closure has been removed at least once since it was first fitted.
In its visible position, the tamper-evident ring 36 is separated from the bottom of the skirt portion 34 of the closure 26 by at least a distance equalling the axial width of the tamper-evident ring. This enables a user, or potential purchaser, to see clearly at a glance that the tamper-evident ring 36 is detached from the closure 26.
The ring 36 is slidable on the waist portion 14 of the neck 12, but is held captive thereon by the shoulder 18 and the abutment flange 20. This ensures that the ring 26 cannot be discarded once it has become detached from the closure 26, and the ring remains on the neck 12 as a permanent indication that the closure 26 has been removed at least once.
The skirt portion 34 of the closure 26 thus acts as a means for concealing the tamper evident ring 36 from view until the closure is removed from the container neck for the first time. The arrangement of the skirt portion 34 of the closure, the severable, or frangible, connections 38, and the abutment flange 20 of the neck together provide means for substantially concealing the tamper evident ring when the closure is fitted to the container neck, until the occasion on which the closure is removed for the first time, and for unconcealing the tamper evident ring, or enabling the ring to be displayed, when the closure is removed for the first time so that the tamper evident ring will remain substantially visible on the container neck when the closure is replaced on the neck. The skirt portion defining the recess in the closure acts as means capable of concealing the tamper evident ring and the frangible bridges act as means for retaining the ring concealed by the skirt portion until the closure is removed for the first time.
The tamper-evident ring 36 is coloured a contrasting colour to the rest of the container and closure, so that it will be clearly visible on the container neck once it has become detached from the closure.
It will be appreciated that this embodiment of the invention is suitable for use with a child-resistant closure, because it does not interfere with the axial movement of the outer closure part 28, and the tamper-evident ring 36 will not become detached if a child tries to open the container 10 by rotating the outer closure part 28. However, the principles of the invention are equally applicable for other types of non-child-resistant screw-on or snap-fit closures.
FIG. 4 shows a modified embodiment including a non-child-resistant closure. In this embodiment, the inner and outer closure parts described previously are replaced by a single-part closure member 48, which may be a screw-threaded closure or a snap-fit closure. The tamper-evident ring 36 is substantially concealed within a lower skirt portion 50 of the closure, and is severably connected thereto by the thin frangible webs 40 in the same manner as described previously.
Although in the preferred embodiment described above the tamper-evident ring is coupled to the closure by severable connections which, in use, are severed by axial forces, in other embodiments, other types of tamper-evident ring may be used. For example, rings which are severed by circumferential twisting forces, or by cutting devices on the neck or closure, may be used.
It will of course be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention. | A container closure assembly is disclosed including a tamper evident ring. The ring is initially substantially concealed by the closure when the closure is first fitted to the neck of the container. After the occasion on which the closure is first removed from the container neck, the tamper evident ring remains substantially visible on the container neck when the closure is replaced on the neck. The closure may include a recess for receiving the ring to conceal the ring, and releasable holding means for retaining the ring in the recess until the closure is removed for the first time. The ring may be slidably retained on a portion of the container neck. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the priority of German Patent Application, Serial No. 10 2014 101 429.4, filed Feb. 5, 2014, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference in its entirety as if fully set forth herein.
BACKGROUND OF THE INVENTION
The present invention relates to a leaf spring arrangement for a motor vehicle axle.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
It is known in the art to equip motor vehicles with axle systems so that the wheels of the motor vehicle are resiliently supported. At standstill, static wheel loads act on the motor vehicle and are superimposed during operation of the motor vehicle with dynamic wheel loads.
Different axle concepts are known, for example a suspended rigid axle or independent wheel suspensions, in order to realize the desired suspension of the motor vehicle. In principle, the wheel is acted upon by a suspension and an attenuation to absorb the static and dynamic wheel loads. Mechanical springs are especially used hereby and may be designed, for example, as round wire springs or also as leaf springs. In order for the leaf springs to be coupled with the motor vehicle axle components, e.g. with the motor vehicle control arms, in particular transverse control arms, it is known to provide a leaf spring at each end thereof with a mount which can be threadably engaged, for example, to a respective transverse control arm and which is typically screwed to the end of the leaf spring by a bolt received in a throughbore in the leaf spring.
FIG. 1 shows a conventional leaf spring 1 configured as transverse leaf spring 2 . The transverse leaf spring 2 has a midsection 3 and two ends 4 . A mount 5 is connected to the each end 4 of the transverse leaf spring by drilling a bore through the end 4 of the transverse leaf spring 2 for passage of a screw bolt 6 so as to couple the end 4 to the mount 5 . The midsection 3 is further provided with attachments 7 to connect the transverse leaf spring 2 to a not-shown motor vehicle body or subframe. A mechanical drilling of the transverse leaf spring 2 in this way to realize the connection between the mount 5 and the end 4 of the leaf spring 2 adversely affects the durability and life of the leaf spring.
It would be desirable and advantageous to provide an improved leaf spring arrangement which obviates prior art shortcomings and which has a long-lasting life while yet being producible in a simple and cost-effective way and reliable in operation.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a leaf spring arrangement for a motor vehicle axle includes a leaf spring made of a fiber composite and having ends, each end having a flat underside to provide a joining surface, and mounts for attachment onto an axle component, the mounts being bonded by an adhesive flatly against the underside of the ends of the leaf spring in an area of the joining surface, each mount having an opening for receiving a metallic bearing or screw bolt.
The present invention resolves prior art problems by applying an adhesive to bond the mount to the end of the leaf spring. Examples of an adhesive include a single-component adhesive or two-component adhesive. Currently preferred is the use of an adhesive that can be thermally activated or an anaerobically curable adhesive. The mount has a flat joining surface which complements the flat joining surface at the end of the leaf spring and is bonded thereto via the adhesive to connect the joining surfaces of leaf spring and mount to one another. The bond at the ends of the leaf spring is effective and allows movements by the suspension and thus any changes in shape of the leaf spring in the inner zone or midsection, while the ends of the leaf spring are able to move in kinematic movement direction but not to move within themselves. Thus, the presence of microcracks, in particular in the bonding zone, is effectively prevented in accordance with the present invention.
According to another advantageous feature of the present invention, the mount may be made of a metallic material. Examples include a steel alloy or light metal alloy.
According to another advantageous feature of the present invention, the leaf spring may be configured as a transverse leaf spring. Currently preferred is the provision of a transverse leaf spring which is made of several layers of a fiber composite. An example of a fiber composite includes a fiberglass composite.
According to another advantageous feature of the present invention, the opening of the mount may extend in substantial orthogonal relation to the joining surface and can be used for receiving a bearing or a bolt to enable connection of the mount with a further axle component, e.g. directly with a transverse control arm or connection to a respective control arm of the wheel suspension via a tie rod or pressure bar.
According to another advantageous feature of the present invention, the flat underside of the ends of the leaf spring may be provided in installation direction. The mount with its joining surface rests flatly against the underside and is bonded thereto by a suitable adhesive.
According to another advantageous feature of the present invention, the mount may be configured to embrace, at least in part, an end face of the leaf spring. Advantageously, an adhesive is applied between the end face of the leaf spring and the mount.
According to another advantageous feature of the present invention, a tie rod or pressure bar may be provided and coupled to the mount to exert a force from the mount in a direction of the end of the leaf spring. The bonding zone in particular is thus acted upon by a compressive force or pressing force such that the presence of a shearing is prevented and any movement to undo the bond between the end of the leaf spring and the mount is avoided.
According to another advantageous feature of the present invention, the mount may include a joining surface and a support shoulder configured to extend beyond the joining surface of the mount with respect to a vertical motor vehicle direction, with the support shoulder resting against the end face of the leaf spring.
According to another advantageous feature of the present invention, the support shoulder may have a contact surface which is bonded with the end face of the leaf spring.
The provision of a bonded joint allows a cost-effective and simple production of the leaf spring. Furthermore, in particular the predominantly transmitting force in pressure direction results in a long durability of the leaf spring arrangement according to the present invention with bonded mount.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
FIG. 1 shows a conventional transverse leaf spring arrangement;
FIG. 2 a shows an exploded perspective view of a leaf spring arrangement according to the present invention;
FIG. 2 b shows a perspective view of the leaf spring arrangement of FIG. 2 a in assembled state;
FIG. 3 a shows a schematic illustration of a leaf spring arrangement according to the present invention with attachment of a tie rod; and
FIG. 3 b shows a schematic illustration of a leaf spring arrangement according to the present invention with attachment of a pressure bar.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to FIG. 2 a , there is shown an exploded perspective view of a leaf spring arrangement 100 according to the present invention. The leaf spring arrangement 100 includes a leaf spring 20 having opposite ends 4 . Each end 4 has an underside 8 with a flat joining surface 9 which complements a joining surface 10 of a mount 50 . Using an adhesive, the joining surface 10 of the mount 50 is bonded to the joining surface 9 , as shown in FIG. 2 b . The mount 50 is provided with an opening 11 which is arranged below the joining surface 9 , as viewed in motor vehicle Z direction, indicated by an arrow. The opening 11 is defined by a longitudinal axis 18 which extends in orthogonal relation to a longitudinal direction 17 of the transverse leaf spring 2 and to the motor vehicle Z direction. With respect to the motor vehicle Z direction, the underside 8 points downwards. The opening 11 of each of the mounts 50 on the opposite ends 4 of the leaf spring 4 can be used for receiving a bearing, in particular a metallic bearing, or a screw bolt, for example.
As shown in FIG. 2 b , the mount 50 is provided with a support shoulder 16 which embraces, at least in part, an end face 12 of the transverse leaf spring 20 so that the support shoulder 16 form fittingly rests against the end face 12 . Advantageously, the support shoulder 16 is bonded by an adhesive to the end face 12 of the transverse leaf spring 20 . The support shoulder 16 provides a self-centering function with respect to the longitudinal direction 17 of the transverse leaf spring 20 , when the mount 50 is connected to the transverse leaf spring 20 . During later operation, the transverse leaf spring 20 undergoes a deflection in motor vehicle Z direction which coincides with a change in length in the longitudinal direction 17 of the transverse leaf spring 20 . The applied forces during changes in length in compressive direction are then additionally compensated by the support shoulder 16 , and the applied forces during changes in length in tensile direction are compensated by the bond between the end face 12 of the transverse leaf spring 20 and the support shoulder 16 .
Advantageously, the support shoulder 16 rests form fittingly against only part of the end face 12 . In particular, the support shoulder 16 covers 10% to 80%, preferably 20% to 60% of the overall area of the end face 12 . Currently preferred is a coverage of 25% to 50%. Advantageously, the end 4 of the transverse leaf spring 20 is not fully encased by the mount 50 , and the mount 50 does not embrace the end 4 of the transverse leaf spring 20 in its entirety so that the mount 50 rests only against the underside 8 and in part against the end face 12 . The adjacent surfaces are advantageously bonded to one another. Also, the mount 50 is sized such that no sides of the transverse leaf spring 20 are embraced.
Adhesive is advantageously applied also between the mount 50 and the end face 12 . This results in a self-centering of the mount 50 upon the transverse leaf spring 20 and additional stability in motor vehicle Y direction.
FIGS. 3 a and 3 b show installation scenarios of the leaf spring arrangement 100 according to the invention. In FIG. 3 a , the end 4 of the transverse leaf spring 20 is coupled with the mount 50 and in kinematic connection with an upper control arm 14 , e.g. a transverse control arm, via a tie rod 13 . A force F, exerted by the control arm 14 , is primarily transmitted upwards through the tie rod, as viewed in the drawing, and causes a compression in the bonded joining surface 10 between the end 4 of the transverse leaf spring 20 and the mount 50 . Stress for both static and dynamic wheel loads mainly occurs in direction of action of the force F so that the tie rod 13 predominantly transmits a depicted tensile load, causing a compression in the joining surface 10 .
FIG. 3 b shows an arrangement with a lower control arm 14 , e.g. transverse control arm, which is coupled by a pressure bar 15 . Thus, a force F is applied via the control arm 14 predominantly in pressing direction of the pressure bar 15 , causing again a compression in the joining surface 10 . Also in this case, the primary force introduction by both static and dynamic wheel loads is established in pressing direction of the pressure bar so that the bond provides sufficient strength and durability between the transverse leaf spring 20 and the mount 50 and is easy to implement.
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. | A leaf spring arrangement for a motor vehicle axle includes a leaf spring which is made of a fiber composite and has ends, each end having a flat underside to provide a joining surface. Bonded flatly by an adhesive against the underside of each end of the leaf spring in an area of the joining surface is a mount for attachment onto a further axle component. The mount has an opening for receiving a metallic bearing or screw bolt. | 1 |
FIELD OF THE INVENTION
The present invention is based on a method and a device for operating an electric motor controlled by pulse width modulation in a direct-voltage network.
BACKGROUND INFORMATION
German patent document DE 199 44 194 A1 discusses a method and device in which the output stage of an electronically commutatable motor is controlled via an electronic control unit using pulse-width-modulated signals. Here, the electric motor is supplied with voltage pulses from a direct-current network corresponding to the control voltage pulses specified by a target value stage.
SUMMARY OF THE INVENTION
The exemplary embodiments and/or exemplary methods of the present invention is to a method and a device for controlling and/or regulating an electric motor. Such electric motors are used for example in motor vehicles in the form of pump motors. In general, the electric motor is supplied with electrical energy from a battery and/or using a generator. The controlling and/or regulation take place using a high-frequency pulse width modulation (PWM). The basic idea of the invention is that when the electric motor is started the PWM is used to continuously increase the motor current required for the operation of the electric motor, e.g. beginning from the value 0.
The advantage of such a controlling of the electric motor is that it makes it possible to avoid current peaks that can result from the large startup currents that occur when electric motors are started. Such current peaks can cause damage to the battery. In addition, these current peaks can cause a dynamic voltage drop, which can cause failure of other consumers also supplied by the battery and/or by the generator.
Therefore, the current gradient with which the motor current is continuously increased is advantageously limited to a prespecified maximum value.
The maximum value, which can also be realized as a target value, can be prespecified dependent on operating parameters of the battery and/or of the generator. Typical operating parameters here are the discharge current of the battery and/or the current increase produced by the generator. In addition, however, the constructive design of the generator can be used to specify the maximum value, for example by determining the maximum rate of current rise that can be achieved by the generator. The latter is defined as the current that can be produced by the generator within a specified period of time.
In order to limit the increase of the motor current, or the current gradient, in an embodiment of the invention it can be provided to limit the rotational speed of the electric motor. Here, for example a maximum target rotational speed can be used that is prespecified dependent on the battery voltage. Another possibility is to take into account the load moment at the electric motor, or that has to be applied by the electric motor, in the determination of the maximum target rotational speed.
In addition, in an embodiment of the invention it is provided that the battery or generator provided for the operation of the electric motor also supplies energy to additional electrical consumers. In this way, the exemplary embodiments and/or exemplary methods of the present invention prevents failure of these additional consumers when current peaks occur during the startup of the electric motor. In a development of the exemplary embodiments and/or exemplary methods of the present invention, it can also be provided that the continuous increase of the motor current, or the current gradient to which this increase is limited, is made dependent on the supplying of the additional consumers with electrical energy. Thus, for example, the current requirement for additional consumers in a vehicle, such as the heating system, the lights, or an ACC (Adaptive Cruise Control) system, can be taken into account in order to determine the allowable current gradient.
In a specific development of the exemplary embodiments and/or exemplary methods of the present invention, it is provided that only the electric motor is supplied with electrical energy by the generator, while the additional electrical consumers are supplied to the greatest possible extent by the electrical energy from the battery. Here, it is also conceivable for this separation of the supplying to take place only during the startup phase of the electric motor.
Further advantages result from the following description of exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows, in a block switching diagram, a device according to the present invention for controlling or regulating an electric motor.
FIG. 2 shows a corresponding switching diagram.
FIG. 3 shows an “equivalent circuit” diagram of the electric motor.
FIG. 4 shows a comparison of the motor current with and without current gradient limiting.
FIG. 5 a shows a depiction to explain the derivation of the rotational speed limitation.
FIG. 5 b shows a depiction to explain the derivation of the rotational speed limitation.
FIG. 5 c shows a depiction to explain the derivation of the rotational speed limitation.
DETAILED DESCRIPTION
During the operation of the electric motor, the startup phase has a high current requirement. If the electric motor is supplied with electrical energy by a battery, a drop in the supply voltage provided by the battery can occur. This dynamic voltage drop can have an adverse effect on other consumers that are also connected to the battery. Especially during the startup of an electrical (pump) motor in a vehicle, for example during pressure buildup in an electro-hydraulic braking system, such a temporarily lowered supply voltage can cause problems in other electrical components in the vehicle.
As a remedy, according to the exemplary embodiments and/or exemplary methods of the present invention the energy supplied to the motor, or the supplied motor current, is increased slowly in order to avoid undesired high current peaks, and to protect the on-board electrical system of the vehicle.
FIG. 1 schematically shows a possible device with which a slow, continuous increase of the motor current at electric motor 180 can be achieved. Here, in a control device 100 there is provided a processing unit 110 , for example in the form of a microprocessor or an ASICS, that evaluates external data and from these data derives control signals that control or regulate electric motor 180 and, if warranted, a generator 190 also present in the vehicle.
As external data, operating parameters of the electric motor itself can be acquired that are recorded by a suitable arrangement 130 and forwarded to processing unit 110 . Operating parameters can also include the pressure ratio in the hydraulic branch before and after a pump motor, which can be determined using pressure sensors or models. In addition, however, prespecified control parameters of the electric motor can also be acquired as operating parameters and can be optionally stored in a suitable storage device directly on the electric motor or in the control device. Such a storage device is schematically represented by block 120 .
In addition, for the initiation of the continuous current increase, it is necessary that a request for the startup of the electric motor be acquired by a corresponding device 140 . In addition, this device can also query the required load moment for the electric motor and can pass this information to processing unit 110 , so that this unit can take this information into account in the controlling.
If a generator 190 is present in the vehicle in which control device 100 is used, its operating parameters can also be used for the production of the control signals of electric motor 180 . For this purpose, the current operating state of generator 190 is acquired, for example using a suitable arrangement 150 . In addition, it is also conceivable that specific design parameters of generator 190 can be taken into account that can be stored in a storage device at the generator or in the control device. Specific design parameters can include for example the maximum rate of current rise that can be produced by the generator, i.e., the current that can be generated within a specified time period.
In addition, the state of battery 160 is acquired and taken into account for the controlling of electric motor 180 . This may be the battery's charge status or the load on the battery by other consumers. However, it is also possible to use a suitable arrangement 170 to purposively acquire the required supply power of the other consumers, in order to produce a prognosis of the load on battery 160 . Such a prognosis can also contribute to the controlling of electric motor 180 , for example if the battery is the only voltage supply for the consumers under consideration.
In another exemplary embodiment, it can also be provided that generator 190 is also capable of being operated dependent on the acquired data and/or dependent on the controlling of electric motor 180 .
FIG. 2 shows a schematic block switching diagram in which control device 200 controls electric motor 220 using a motor voltage U M or a motor current I M . Typically, such a controlling is carried out using a (high-frequency) pulse width modulation. The energy supply to control device 200 or to electric motor 220 is provided in the present case by a battery 230 that supplies a battery voltage U Bat , and by a generator 210 . Through the combination of the battery and the generator, control device 200 or electric motor 220 can be supplied with a higher current I Zul .
Because the generator and the battery in the vehicle are standardly connected in parallel and the generator is limited to a certain rate of current rise (e.g. 300 to 1000 A/s), when there is a jump-type switching on of the motor the current is supplied from the battery. These high currents can damage the battery. Through the specification of a maximum current gradient, i.e. a defined current increase in a specified time period in the controlling of the motor during startup, such damage can be avoided. If, in addition, the current gradient is adapted to the rate of current rise of the generator, the motor current required to run up the motor can be produced completely by the generator of the vehicle. This protects the battery against high current jumps. In addition, such a controlling avoids dynamic voltage drops in the on-board electrical system, because the battery is relieved of stress.
The comparison of the load of a motor startup with and without current gradient limitation is shown in FIG. 4 . Here, the motor current I M required to start up the motor is plotted over time t. The curve according to 420 shows motor current I M without current limitation having a very high current peak shortly after the start of the runup. In contrast, the dashed curve according to 400 shows a continuous curve that after a certain time goes over into a constant current requirement for the operation of the motor, as does the curve according to 420 .
In another exemplary embodiment, different current gradients can also be set that are required according to the hydraulic power requirements of an ESP controller in the vehicle.
Because the electric motor typically also has a rotational speed control unit, the setting of the maximum current gradient can be carried out by specifying a target rotational speed. In a particular exemplary embodiment, the maximum target rotational speed used in this way is calculated as follows:
ω
i
j
+
1
=
1
k
8
(
Δ
i
batt
max
-
k
9
)
The maximum target rotational speed can be derived as follows:
As can be shown on the basis of an equivalent circuit diagram of the electric motor (see FIG. 3 ), the motor voltage U M can be divided into different partial voltages U R (allocated to ohmic resistance 300 of the motor), U Ind (allocation to the inductive resistance 320 of the motor), and U Gen (allocation to the generator portion 340 of the motor).
The system equations of the motor can be derived from the voltage balance and the principle of conservation of angular momentum, and are as follows:
J
ⅆ
ω
ⅆ
t
=
Ki
-
T
load
L
ⅆ
ⅈ
ⅆ
t
=
U
-
Ri
-
K
ω
(
1.1
)
The quantities here are the armature current i and the rotational speed ω. The parameters are inductance L, moment of inertia J, motor constant K, and resistance R. The inputs to the system are the manipulated quantity supply voltage U and load moment T load . The load moment is dependent on the pressures adjacent to the pump elements and on the rotational speed. To a first approximation, the rotational speed dependence can be ignored.
Thus, the load moment is made up of a constant friction portion and a pressure-dependent load portion:
T load =T fric +k load ( p ds −p ss .
Here, p ds is the pressure at the pressure side and p ss is the pressure at the suction side, whose values are taken for example from HIM (hydraulic model of the ESP) or can be acquired directly by pressure sensors. Thus, the load moment can be presumed to be known.
In the following, supply voltage U is calculated in such a way that the desired target rotational speed results. The basis of this is the theory of flat systems.
If, as output, rotational speed ω is selected
y=ω (1.2),
through a first differentiation and placement into the system equations (1.1) a relation is obtained between armature current i and angular acceleration:
y
.
=
ω
.
=
1
J
(
Ki
·
T
load
)
⇒
ⅈ
=
1
K
(
J
ω
.
+
T
load
)
.
(
1.3
)
Further differentiation yields the supply voltage U:
y
¨
=
ω
¨
=
K
JL
(
U
-
Ri
-
K
ω
)
+
T
.
load
J
.
(
1.4
)
Solving for U yields the following:
U
=
JL
K
ω
¨
+
RJ
K
ω
.
+
K
ω
+
R
K
T
load
+
L
K
T
.
load
.
(
1.5
)
This equation can be simplified due to the small influence of the inductance. By putting in the target quantities, a controlling is thus obtained that moves the system along the target trajectory ω d :
U
d
=
RJ
K
ω
.
d
+
K
ω
d
+
R
K
T
load
.
(
1.6
)
Here, the first term takes into account the inertia of the motor, the second term takes into account the voltage induced by the rotation, and the third term takes into account the voltage required due to the load moment.
Planning the Target Trajectory
The sampling rate of the control device is 5 ms. Therefore, both supply voltage U and target trajectory ω d (t) can be modified in these time steps. In a first step, here the trajectory is planned over a sampling cycle. This is shown in FIG. 5 a.
At time j, the target rotational speed at time j+1 is selected such that it is the case both that manipulated quantity limitations are observed and also the current gradient does not exceed the required maximum. In the following, the calculation of the new target value ω d j+1 is described in more detail. For this purpose, first it is necessary to calculate the regulation.
Calculation of the Regulation
For the regulation of the target rotational speed, a linear PI regulator is used. Thus, the regulator portion is made up of a proportional part and an integral part. Thus, the general regulator equations can be written as follows in discretized notation:
U
PI
j
=
k
p
(
ω
d
j
-
ω
meas
j
)
︸
U
j
P
+
k
i
∑
1
=
1
j
(
ω
d
j
-
ω
meas
j
)
︸
U
j
i
However, here the fact must be taken into account that the supply voltage U associated with time j is not outputted until time j+1, so that the target trajectory is shifted by a sampling cycle. This fact is illustrated in FIG. 5 b.
Thus, in the regulator the current rotational speed is compared with the target rotational speed of the last cycle.
Thus, the following equation results for the regulator:
U PI j =( k p +k i )(ω d j−1 −ω mass j )+ I (3.1)
Controlling and Regulation
Manipulated quantity U is made up of pre-controlling U d and regulation U PI :
U
=
U
d
+
U
PI
=
RJ
K
ω
.
d
+
K
ω
d
+
R
K
T
load
+
U
PI
.
(
3.2
)
Here, the rotational speed and angular acceleration used in the controlling still have to be determined. The angular acceleration is determined by linear interpolation of the target rotational speed at times j and j+1:
ω
.
d
=
ω
d
j
+
1
-
ω
d
j
Δ
t
(
3.3
)
Thus, manipulated quantity U j+1 at time j+1 results from:
U
j
+
1
=
(
RJ
K
Δ
t
)
︸
k
1
ω
d
j
+
1
+
(
K
·
RJ
K
Δ
t
)
︸
k
2
ω
d
j
+
R
K
T
load
j
+
U
PI
j
.
(
3.4
)
Here care is to be taken that only the control portion is dependent on the new target quantity ω d j+1 . In the following, this equation is used in order to prevent limitations of manipulated quantities.
Maintenance of Manipulated Quantity Limitations
The rotational speed regulation unit obtains a target rotational speed from higher-order functions. However, it cannot be guaranteed that the pump is capable of executing this speed. Therefore, at the next time (j+1) the target rotational speed should be modified such that manipulated quantity limitations are fulfilled, and the rotational speed can therefore be achieved by the pump. In the following, (3.4) is used to calculate an upper limit ω j+1 max and a lower limit ω j+1 min for the target rotational speed, within which the manipulated quantity limitations are to be held. The target rotational speed is limited by the limits:
ω
mod
j
+
1
=
{
ω
min
j
+
1
w
d
j
+
1
<
ω
min
j
+
1
ω
d
j
+
1
for
ω
min
j
+
1
≤
ω
d
j
+
1
≤
ω
max
j
+
1
ω
max
j
+
1
ω
d
j
+
1
>
ω
max
j
+
1
(
4.1
)
The two limits can be calculated using (3.4). By solving (3.4) for ω j+1 and putting in the maximum voltage, the upper limit is obtained:
ω
max
j
+
1
=
1
k
1
(
U
max
-
k
2
ω
d
j
-
R
K
T
load
j
-
U
PI
j
)
.
(
4.2
)
Putting in the minimum voltage U=U min , yields the lower limit.
ω
min
j
+
1
=
1
k
1
(
U
min
-
k
2
ω
d
j
-
R
K
T
load
j
-
U
PI
j
)
(
4.3
)
Thus, using (4.1)-(4.3), it can be assured that manipulated quantity limitations are maintained. However, very large current gradients can still occur. The limitation of the current gradients is described below.
Limitation of the Current Gradients
a. Limitation of the Motor Current Gradient
From the moment-balance system (1.1), the current im at time m can be expressed dependent on the load moment and the angular acceleration.
i
m
=
1
K
(
T
load
m
+
J
ω
.
m
)
.
(
5.1
)
For the limitation of the current gradient, the modification of the current between the sampling steps is decisive. Using (5.1), the current modification can be determined dependent on the change in the load moment and the change in the angular acceleration:
Δ
i
j
+
1
=
i
j
+
1
-
i
j
=
J
K
(
ω
.
j
+
1
-
ω
.
j
)
+
1
K
(
T
load
j
+
1
-
T
load
j
)
(
5.2
)
Putting in the maximum allowed current change Δi max yields the maximum angular acceleration:
ω
.
max
j
+
1
=
K
J
Δ
i
max
+
ω
.
j
-
1
J
(
T
load
j
+
1
-
T
load
j
)
︸
≈
T
load
j
-
T
load
j
-
1
.
(
5.3
)
Here it is to be noted that the change in the load moment due to the unknown load moment at time j+1 is approximated by the load moment change of the last cycle. Thus, through linear approximation of the angular acceleration, another condition is obtained for the new target rotational speed ω d j+1 :
ω
.
d
j
+
1
=
ω
j
+
1
-
ω
j
Δ
t
≤
ω
.
max
j
+
1
(
5.4
)
ω
i
j
+
1
=
ω
j
+
Δ
t
ω
.
max
j
+
1
.
(
5.5
)
Thus, in addition to the limitations from (4.1) the new target rotational speed is subject to the limitation
ω d j+1 ≦ω i j+1 (5.6)
Under nominal conditions (no modeling errors, ideal load moment estimation), the allowed motor current gradient can thus be maintained through condition (5.6). It is to be noted that both modeling errors and errored load moment estimates can result in deviations.
b. Limitation of the Battery Current Gradient
The decisive factor for the load on the vehicle electrical system is not directly the motor current i mot , but rather the battery current i bat required by the PWM generator. FIG. 5 c shows the PWM generator and its interfaces.
Due to the smoothing of the battery current by filters and the high clock frequency, here averaged direct voltages are assumed. Dependent on the PWM sample ratio and the battery voltage, the motor voltage is calculated as follows:
U mot =PWM U bat . (5.7)
If the energy balance of the PWM generator is taken into account:
U bat i bat =U mot i mot
the following is obtained for the battery current:
i bat =i mot PWM. (5.8)
For the current gradients of the battery voltage, the following thus holds:
{dot over (i)} bat ={dot over (i)} mot PWM+i mot P{dot over (W)}M
or, written with differences, there follows:
Δi bat j+1 = Δi mot j+1 PWM j +i mot j ΔPWM j+1 . (5.9)
Here, the motor current of the last cycle i mot j and the PWM j can be calculated from known quantities of the last cycle:
i
mot
j
=
U
j
-
K
ω
d
j
R
PWM
j
=
U
j
U
batt
.
(
5.10
)
The motor current difference can be expressed as follows, with the help of the motion equation:
Δ
i
j
+
1
=
i
j
+
1
-
i
j
=
J
K
(
ω
.
j
+
1
-
ω
.
j
)
+
1
K
(
T
load
j
+
1
-
T
load
j
)
︸
≈
(
T
load
j
-
T
load
j
-
1
)
=
Δ
T
(
5.11
)
If the angular acceleration of the j+1 cycle is replaced by the corresponding difference approximation, the following is obtained:
Δ
i
j
+
1
=
J
K
(
ω
j
+
1
-
ω
j
Δ
t
-
ω
.
j
)
+
1
K
Δ
T
=
J
K
Δ
t
︸
k
3
ω
j
+
1
-
J
K
Δ
t
ω
j
-
J
K
ω
.
j
+
Δ
T
K
︸
k
4
.
(
5.12
)
The change in the PWM is calculated from the quotient of supply voltage U and battery voltage U bat :
Δ
PWM
j
+
1
=
PWM
j
+
1
-
PWM
j
=
U
j
+
1
U
batt
-
PWM
j
.
(
5.13
)
The calculation of the supply voltage U was already derived above (see (3.4)):
U
j
+
1
=
(
RJ
K
Δ
t
)
︸
k
1
ω
j
+
1
+
(
-
RJ
K
Δ
t
+
K
)
︸
k
2
ω
j
+
R
K
T
load
j
︸
k
5
.
(
5.14
)
In order to prevent feedback effects of the regulation on the trajectory planning, here the regulation portion is ignored.
If this is put into the change of the PWM:
Δ
PWM
j
+
1
=
k
1
ω
j
+
1
+
k
5
U
batt
-
PWM
j
=
k
1
U
batt
︸
k
6
ω
j
+
1
+
k
5
U
batt
-
PWM
j
︸
k
7
(
5.15
)
Putting (5.12) and (5.15) into (5.9), the following is obtained:
Δ
i
batt
j
+
1
=
(
k
3
ω
j
+
1
+
k
4
)
PWM
j
+
i
mot
j
(
k
6
ω
j
+
1
+
k
7
)
=
ω
j
+
1
(
k
3
PWM
j
+
k
6
i
mot
j
)
︸
k
8
+
k
4
PWM
j
+
k
7
i
mot
j
︸
k
9
(
5.16
)
Or, solved for rotational speed ω j+1 :
ω
j
+
1
=
1
k
8
(
Δ
i
batt
j
+
1
-
k
9
)
(
5.17
)
If the maximum allowed value is put in for the battery current change, the associated target rotational speed is obtained:
ω
i
j
+
1
=
1
k
8
(
Δ
i
batt
max
-
k
9
)
(
5.18
) | A method and a device for controlling and/or regulating an electric motor. Such electric motors are used for example in motor vehicles in the form of pump motors. In general, the electric motor is supplied with electrical energy from a battery and/or using a generator. The controlling and regulation take place using a high-frequency pulse width modulation (PWM). When the electric motor is started, the PWM is used to continuously increase the motor current required for the operation of the electric motor, e.g. beginning from 0. | 7 |
FIELD
The present invention pertains to boat maintenance and more particularly to a method and apparatus for cleaning a boat in the water while avoiding or minimizing pollution.
BACKGROUND
The necessity of having to clean the hull of a boat periodically has long been known. Marine organisms must be removed for hull preservation and boat efficiency. Hulls may need old paint removed and new paint applied. Decks and other boat parts also need to be cleaned. If the boat is cleaned in the water, these cleaning tasks typically involve brushing both above and below the waterline. Sanding and the use of various cleaning agents and paint strippers may also be used above the waterline.
Although such cleaning may be effective to maintain a boat, boat cleaning is also known to result in air and/or water pollution, unless special precautions are taken. Brushing and sanding the hull release contaminants, such as old paint containing lead. If cleaners are used, they are usually toxic. Even if the deck of a boat is washed down with fresh water, polluting materials can be discharged or washed overboard.
Voluntary campaigns to control pollution from boat cleaning have been organized, but unfortunately these efforts have not been sufficiently effective. Because of continued concerns about the environment, ever more stringent federal and state laws and programs with tough penalties have been, or are being, enacted or proposed. Under these laws, severe fines and even jail terms have been imposed for those who still pollute the harbor waters as a result of boat cleaning.
A well-recognized way of avoiding water pollution is to clean the boat on land, although the problem of air pollution still exists. Moreover, having to haul a boat onto land to perform the cleaning tasks is inconvenient and expensive, especially burdensome for routine maintenance. As a result many boats are still being cleaned in the water notwithstanding the resulting pollution.
Apart from applicant, no practical and relatively economical solution to the environmental problems associated with routine boat cleaning is known to exist in the past. Some have tried to minimize the fouling of the boat's hull by covering it while moored. For example, the U.S. Patent to Faidi U.S. Pat. No. 5,549,069 discloses a bag that is pressed against the hull a shield the hull from the water. However, providing a protective cover for the hull does not directly address the problem of cleaning as described above, which in any event may be required. If chemicals are placed in the bag to dissolve marine growths, the chemicals may escape into the water. On the other hand, the U.S. Patents to Seiple U.S. Pat. No. 3,752,109 and to Feurt U.S. Pat. No. 4,784,078 do disclose floating hull cleaning equipment so that hull cleaning can take place in the water. These are complicated constructions, expensive to build and use, and do not allow routine boat maintenance at a typical dock or slip. Moreover, Seiple has no provision for avoiding pollution, and Feurt, although providing for the evacuation of contaminated water, does not prevent contaminates from escaping through the entrance and exit curtains.
To applicant's knowledge, applicant's prior U.S. Pat. No. 5,138,963 discloses the only method and apparatus that directly addresses the problem of cleaning a boat hull in the water and at a typical slip while avoiding pollution. Although the concepts disclosed in this earlier patent are still valid, the subject invention provides certain improvements.
SUMMARY
An apparatus and method are disclosed for cleaning a boat in the water while avoiding or minimizing pollution. Included are a floating, water-impervious basin and a filtration system. The basin has side walls sloped downwardly to a nadir spanning substantially the full length of the basin, an opening allowing the surrounding water to enter the basin as well as ingress and egress of boats, and a gate movable into a closed position over the opening and forming a cleaning chamber in the basin containing a pool of water. After the gate is closed behind a boat, the boat is floating in the pool of water that is now isolated from the surrounding water. As the gate is closing behind a boat, it allows water to pass therethrough to facilitate closure and to control the volume of water in the chamber, and yet is substantially sealed when closed. The filtration system includes a collector pipe lying submerged in the nadir and a pair of return pipes that float on the water in the basin. The sloped side walls and water exiting from the return pipes facilitate movement of materials resulting from the cleaning operation toward the collector pipe. The filtration system sucks the water-borne materials into the collector pipe, pumps them through a filter, and returns clean water to the basin through the return pipes. The relationship of the pipes and the basin facilitates reversibility of the basin so that its exterior surface may be periodically cleaned.
An object of the present invention is to clean a boat in the water without causing pollution.
Another object is to facilitate routine maintenance of a boat without causing pollution.
An additional object is to provide a closed system for cleaning the hull and other parts of a boat while in the water, wherein the substances removed from the boat and the materials used to remove them are collected and filtered out and are not allowed to escape into the surrounding water or air.
A further object is to provide a basin into which a boat is placed for cleaning, wherein the shape of the basin facilitates collection and removal of the substances cleaned off the boat and of the materials used to clean the boat.
Yet another object is to form a sheet of flexible waterproof material into a floatable, boat cleaning basin of desired shape, in which a boat may be placed for cleaning purposes, and which facilitates removal of contaminates that result from cleaning the boat in the water.
A still further object is to provide a collector that cooperates with the shape of a basin in which a boat may be cleaned while in the water for the purpose of facilitating the collection and removal of undesirable substances and cleaning materials.
Another object is to provide a boat cleaning apparatus that includes a cooperating pre-shaped basin and filtration system that facilitates movement of contaminated water and solid materials toward a collection area, collects contaminated water from the basin, and returns cleaned water to the basin.
An additional object is to provide a waterproof, floatable boat-cleaning basin that is made of flexible material, that can be configured to retain a desired shape under water and around the hull of a boat, and that resists billowing out of such shape by controlling the volume of water in the basin.
Another object is to provide a collector pipe for a boat cleaning apparatus that cooperates with the cleaning basin of the subject apparatus so that the pipe assists in maintaining the shape of the basin when a boat is floating in water within the basin.
A still further object is to return cleaned water to the pool of water in the cleaning basin of a boat maintenance apparatus so that the water is returned without causing undesirable turbulence in the pool.
An additional object is control the buoyancy of different parts of an apparatus for cleaning a boat in the water in order to control the positions of the parts and their interaction.
Yet another object is to provide a basin, a collector pipe, and return pipes used in a boat maintenance apparatus that cooperate to facilitate easy reversibility of the basin, so that both of its surfaces can be periodically cleaned.
Another object is to provide a gate for a cleaning basin of a boat cleaning apparatus wherein the gate is movable from an open position to a closed position, and while closing, releases water from the basin so as to assist in controlling the volume of water in the basin.
Still an additional object is to provide a gate for a cleaning basin of a boat cleaning apparatus wherein the end wall formed by the gate, and its opposite end wall in the basin, help to retain the desired shape of the basin during the boat cleaning operation.
Yet another object is to provide a boat maintenance apparatus that is adaptable for use by existing boat maintenance facilities so as to reduce the amount of pollution caused by such existing facilities during their boat maintenance operations; for boatyards that have slips used for boat maintenance; and for individual boat owners who desire to clean their own boats, especially routine maintenance on a more frequent basis.
An additional object is to provide a boat maintenance apparatus that is suitable for use with various sizes of boats and types of boats, including both powerboats and sailboats, and various sizes of docks and slips.
A further object is to provide a boat maintenance apparatus that is composed of parts that can be readily assembled and subsequently disassembled, and in the disassembled condition can be folded and otherwise arranged for transport and storage.
A still further object is to provide a boat maintenance apparatus that is resistant to the corrosive action and other adverse effects of seawater but may be cleaned or repaired if damage does occur.
These and other objects, features and advantages of the present invention will become apparent upon reference to the following description, accompanying drawings, and appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of an embodiment of the subject boat maintenance apparatus floating in a floating dock, the apparatus including a cleaning basin and a filtration system. FIG. 1 shows the collector and return pipes of the filtration system removed from the basin and in resting positions on the dock and further shows the gate of the basin floating in an open position.
FIG. 2 is a top plan view of the apparatus and dock shown in FIG. 1 .
FIG. 3 is an end elevation of the apparatus and the dock as viewed from the left end of FIGS. 1 and 2 but with the collector and return pipes shown in their operating positions in the basin.
FIG. 4 is a view similar to FIG. 1 but with gate closed and the collector and return pipes in their operating positions.
FIG. 5 is top plan view of the apparatus and dock shown in FIG. 4 .
FIG. 5 a is a somewhat enlarged, fragmentary section taken on line 5 a — 5 a in FIG. 5 .
FIG. 6 is an end elevation of the apparatus and dock shown in FIGS. 4 and 5 as viewed from the left end of FIGS. 4 and 5.
FIG. 7 is a plan view of the main sheet from which the side walls and gate of the basin of the subject apparatus are formed, it being noted that, except for rolled sleeves at several edges, this sheet is lying flat with the side walls and gate being in a common plane.
FIG. 8 is a plan view of the end sheet constituting the end wall of the basin of the subject apparatus prior to its assembly with the main sheet shown in FIG. 7 .
FIG. 9 is an isometric view of the main and end sheets assembled into the basin of the subject apparatus showing the gate in an open position.
FIG. 9 a is an enlarged fragmentary section taken on-line 9 a — 9 a in FIG. 9 .
FIG. 9 b is an enlarged fragmentary section taken on line 9 b — 9 b in FIG. 9 .
FIG. 10 is a fragmentary perspective view of the dock and basin showing the gate in open position, it being noted that the collector and return pipes are omitted for clarity.
FIG. 11 is a view similar to FIG. 10 but showing the gate in a partially closed position, that is, showing the gate as it is being moved from its open position into its fully closed position wherein water in the chamber of the basin is allowed to escape into the surrounding water through a passageway between the panels of the gate.
FIG. 12 is also a view similar to FIG. 10 but showing the gate in its fully closed position.
FIG. 12 a is a fragmentary enlarged plan view of the aft end of the basin, as viewed from a position indicated by line 12 a — 12 a in FIG. 12, showing the gate nearly closed, this view being for the purpose of showing the relationship of the panels of the gate in their closed positions.
FIG. 12 b is a fragmentary enlarged section taken on line 12 b — 12 b in FIG. 12 .
FIG. 13 is a perspective view of the subject boat maintenance apparatus in fully assembled condition floating within a floating dock, showing the aft end of the collector pipe resting in the nadir of the basin, showing one of the return pipes and part of the return manifold both floating on the water in the basin, and showing the gate open.
FIG. 14 is a side elevation of the subject apparatus and dock, showing the gate in closed position and a boat floating in the pool of water in the basin.
FIG. 15 is a top plan view of the floating dock, the basin floating in the dock, and the boat floating in the basin, it being noted that the superstructure of the boat of FIG. 14 is omitted for simplicity and to indicate that boats of various types may be serviced in the subject apparatus, and it being further noted that return piping is shown floating both port and starboard and forward of the boat.
FIG. 16 is a transverse vertical section taken on line 16 — 16 in FIG. 15 .
FIG. 17 is schematic diagram of the filtration system used in the apparatus of the present invention.
DETAILED DESCRIPTION
The number 20 in the drawings generally indicates an embodiment of a boat maintenance apparatus for cleaning the hull and other parts of a boat. The apparatus may be supported in the water from a dock or slip 22 , or other suitable structure. As shown, the dock is floating in seawater 24 and is U-shaped having spaced side portions 26 , a closed forward portion 28 , and an open aft end 30 . Notwithstanding the reference to “seawater,” it is understood that the subject invention is not limited to use in seawater but may be used in bodies of fresh water, although it is more likely to be used in cleaning boats that have been subjected to the effects of seawater. For purposes of subsequent reference, the level of the water outside of the apparatus is indicated by the number 32 . The dock is provided with a plurality of cleats 36 spaced along the side and rear portions. With particular reference to FIGS. 1-6 and 10 , the subject boat maintenance apparatus 20 includes a cleaning basin 42 and a water filtration system 44 . Each of these main components of the subject apparatus will now be described in detail.
The basin 42 (FIGS. 7-9) is made of sheet material that is flexible, durable, chemically and ultraviolet resistant, waterproof or impervious, relatively lightweight, and resistant to algae and other corrosive and deteriorating effects of seawater. Development of the subject apparatus indicates that vinyl sheet of the type used for lining swimming pools is very suitable for the purposes of the present invention. More particularly, thirty-mil vinyl sheet sold under the trademark Plastimayd by the Plastimayd Corporation of Clackamas, Oreg., 97015, has been successfully used for the subject basin. It should be understood, however, that there are many other sheet materials having the foregoing qualities that would be suitable for the subject basin, and thus the invention is not limited to the Plastimayd sheet. In general, my development indicates that sheet material of the foregoing qualities of a thickness in the range from about thirty mils to about forty mils is preferable for the subject basin. Moreover, for a basin to be used in a dock having a length of about forty-eight feet and an opening of about eighteen feet, a basin made of the Plastimayd sheet will weight approximately two hundred-fifty pounds, a weight that can be handled by one person. Sheet materials that result in much greater weight could be used but because of the handling problem, are not preferred.
With continued reference to FIGS. 7-9, the basin 42 is formed from an end sheet 50 and a main sheet 52 of the selected material. The end sheet or piece is planar and in the shape of an equilateral triangle having side edges 54 and an upper edge 56 . The end sheet constitutes the end wall of the basin and for simplicity is given the same reference numeral, namely 50 , as the end wall The upper edge of the end wall is formed with a sleeve 58 along its length.
The main sheet 52 is also shown in its flat planar condition in FIG. 7 . Although this main sheet is formed into a V-shape, it will first be described in its flat condition so as to enable a better understanding of how the basin is formed. In its flat condition, the main sheet may be thought of as being divided into the various walls or panels of the basin into which it will be formed, it being understood that in the preferred embodiment, these walls and panels are not delineated on the sheet, although for descriptive purposes, they are so illustrated in the drawings. Thus, the sheet has rectangular, planar port and starboard side walls 64 and 66 with each sidewall having an upper edge 68 , a forward end edge 70 , an aft end edge or fold line 72 , the later being shown in dashed lines to indicate that it is merely an eventual fold line in the sheet. The side walls meet along a central juncture or eventual fold line 74 that extends from one end edge 70 to the other end edge 72 of the panels. The end edges 70 and 72 , the upper edge 56 , and the side edges 54 are all of equal length. In addition, the upper edges 68 and the juncture 74 are of equal length.
Sleeves 80 (FIGS. 7-9) are provided along the upper edges 68 of each side wall 64 and 66 , extending from end to end of the upper edges. In addition, grommets 82 are provided in the side walls in inwardly adjacent relation to the sleeves at the forward and aft comers and centrally therebetween.
The main sheet 52 of the basin 42 also includes a gate 90 (FIGS. 7 and 9) that extends rearwardly from the side walls 64 and 66 and is planar with the side walls when the sheet is laid out flat as shown in FIG. 7 . As with the walls 64 and 66 , the main sheet may be thought of as having port and starboard panels 92 and 94 and an intermediate panel 96 between the port and starboard panels. The port and starboard panels have outer edges 98 equal in length to the length of the edges 54 , 56 , 70 and 72 . The intermediate panel also has an outer edge 100 of this same length and which joins the outer edges 98 of the port and starboard panels. Sleeves 102 of smaller diameter than the sleeves 58 and 80 are formed in the outer edges 98 .
With continued reference to FIGS. 7, 8 and 9 and, the main sheet 52 is initially folded along the juncture 74 to bring the side panels 64 and 66 into a V-shaped relationship to each other. It is to understood that because of the sheet material used, such folding produces merely rounding along the juncture as opposed to creasing. The end sheet or wall 50 is assembled with the folded main sheet so that the side edges 54 mate with the forward end edges 70 and the upper edge 56 spans the distance between the forward ends of the upper edges 68 . The end and side walls are then hot sealed together in this assembled relationship, as best seen in FIG. 9, wherein the end wall maintains the side walls in the V-shaped relationship, although with the gate 90 open and the basin 42 not confined within the dock 22 , as shown in FIG. 9, the side walls may diverge rearwardly somewhat towards the gate. When the gate is closed, however, in a manner to be described, and as shown in FIGS. 5, 6 , 12 and 15 , for example, the complete basin 42 is formed with the gate having the same triangular shape and size as the end wall 50 .
To describe the closing of the gate 90 , reference is initially made to FIG. 7 . There, it will be seen that the starboard and port panels 92 and 94 have imaginary first and second fold lines respectively 106 , 108 , 110 and, 112 . All of these fold lines as well as the center fold line or juncture 74 of the panels intersect at a point 114 . The first fold lines 106 and 110 of the starboard and port panels are collinear, whereas the second fold lines 108 and 112 extend from the intersection point 114 rearwardly to the aft ends or corners 116 and 118 on the starboard and port panels, respectively.
Closing of the gate 90 may be initiated at either the starboard or the port panel 92 or 94 (FIGS. 7 and 9 ). Assuming that closing of the gate is initiated with the starboard panel, the corner 116 of the starboard panel is brought transversely of the basin 42 to the aft end of the upper edge 68 of the port side wall 64 . In so doing, the gate folds along the first fold line 106 and the second fold lines 108 and 112 . This causes the intermediate panel 96 to be brought into substantially parallel relation with the port panel 94 and the starboard panel 92 to be brought into parallel relation with the end wall 50 . It is to be noted that the folds along the first fold line 106 and the second fold line 112 project outwardly of the basin, whereas the fold along the second fold line 108 projects inwardly of the basin. In other words, the second fold line 108 is brought into substantially parallel, adjacent relation to the first fold line 110 .
Closing of the gate (FIGS. 7 and 9) is completed by bringing the now adjacent and parallel port and intermediate panels 94 and 96 transversely forwardly up into adjacent parallel relation against the starboard panel 92 , with the folding action occurring along the second fold line 108 and the first fold line 110 so that the first fold line 106 and the second fold line 112 are now in adjacent parallel relation to each other. The gate is then held in this closed position in a manner to be described thereby forming the basin into a polyhedral, trough shape, or what may be visualized as an inverted tent.
With the basin 42 (FIGS. 4-6) formed in the manner described above and understanding that the basin is used in a horizontal upwardly open orientation, the side walls 64 and 66 converge or slope downwardly to the juncture 74 which constitutes a nadir at the bottom of the basin. Moreover, the side and end walls 64 , 66 and 50 meet in a lower forward tip 122 , the side walls and the gate 90 meet in an aft tip 124 , with the nadir extending the full length of the basin between these tips, and the end wall and the gate are in opposed parallel relation to each other. In the closed position of the gate, the basin provides a chamber 130 , which is substantially sealed by the integral association of the end and side walls and because of the folded relationship of the panels 92 , 94 and 96 of the gate.
Hollow side and end flotation tubes 140 and 142 are fitted in the side and end sleeves 80 and 58 , respectively, of the basin 42 , and have their ends capped. These tubes are preferably made of PVC flotation pipe (FIG. 5A) of sufficient diameter to provide positive buoyancy in order to support the basin 42 in the water. On the other hand, flotation tubes 146 (FIGS. 9, 9 A) are fitted in the sleeves 102 of the port and starboard panels 94 and 92 but are filled with lead shot 148 , and their ends capped, in order to provide these tubes with a measure of negative buoyancy, for a purpose to be described. Still further, grommets 150 are provided in the port, starboard and intermediate panels 94 , 92 , 96 adjacent to corners 116 and 118 and the fold lines 106 and 110 .
The basin 42 is fitted within the slip of the dock 22 as best seen in FIGS. 2, 3 , 5 , 6 , 13 and 15 . It will thus be understood that the sheets 50 and 52 from which the basin is constructed are dimensioned so as to fit the basin within the slip and that these dimensions may be varied to fit slips of various sizes. That is, as fitted in the slip, the end wall 50 and the upper edges 68 of the side walls 64 and 66 are in closely adjacent spaced relation to the front and sides 28 and 26 , respectively, of the dock. Furthermore, the common aft end edge 72 of the side walls is in substantial alignment with the opening 30 in the dock so that when the basin is fully within the dock, the gate 90 in its open position extends rearwardly from the dock, as best seen in FIGS. 1, 2 , 10 and 13 . Because of the flotation tubes 140 and 142 as well as the sheet material from which the basin is made, the basin floats within the dock and is moveable upwardly and downwardly in the water relative to the dock.
Because of the negative buoyancy of the flotation tubes 146 , however, the gate 90 in its open position extends downwardly and rearwardly from the aft end of the dock as seen in FIGS. 1, 3 , 10 and 13 . The buoyancy of the flotation tubes is adjusted by adding more or removing some of the lead shot 148 in the tubes so as to maintain the gate at the desired downwardly sloping angle in its open position. In other words, the gate must extend rearwardly and downwardly in order to allow entry and egress of boats into and out of the basin 42 without the keel, the rudder or propeller of a boat becoming fouled with the basin. Furthermore, the gate must not hang vertically downwardly from the dock since this will tend to lift the sidewalls 64 and 66 upwardly, again causing interference with the boat. Tie lines 160 (FIGS. 2, 3 , 5 , 6 , 15 and 16 ) extend through the grommets 82 in the basin and are fastened around the cleats 34 thereby tethering the basin to the dock while allowing relative vertical movement of the basin and the dock.
As thus floating and tethered, the side and end walls 64 , 66 and 50 of the basin 42 extend downwardly from the dock 22 with the side walls in the previously described V-shaped relationship. The construction of the basin 42 in the manner described above is accomplished so as to provide an angle of decline or slope of the side walls that is from about forty-five degrees to about sixty degrees to the horizontal. With the gate 90 open, as shown in FIGS. 1, 2 and 3 , for example, water of course enters the basin from the surrounding sea water 24 . The trough-like or inverted tent shape of the basin results from the construction of the basin, as above described, but also because the weight of the water within the basin tends to maintain this shape, as long as the weight of the water does not exceed certain limits, as further described below.
With the gate 90 in closed position (FIGS. 5, 12 and 15 ), the end and side walls 50 , 64 and 66 and the gate form the closed working or cleaning chamber 130 previously described. Moreover, when the gate closes, it captures a pool 170 of water in the chamber having a water level 172 very close to but below the upper edges 56 and 58 of the basin including the gate. Since the forward end wall 50 is integral with the side walls, no water can escape from the forward end of the basin. In addition, because of the folded panels 92 , 94 and 96 of the gate, the gate essentially seals the aft end of the basin so that no water can escape through this route (FIG. 12 A).
In order to limit the amount of water that is retained in the pool 170 , the gate 90 allows water to exit from the basin 42 while the gate is being closed. More specifically, with reference to FIGS. 10, 11 and 12 , the steps of closing the gate are further described. When the starboard corner 116 is brought up to the aft end of the port sleeve 80 , a passageway 180 is formed between the intermediate and port panels 96 and 94 , allowing water to escape from the basin into surrounding sea water as indicated at 182 (FIG. 11 ). When the port and intermediate panels are folded up against the starboard panel 92 , as shown from FIG. 11 to FIG. 12, water is allowed to escape at 184 from between the intermediate and starboard panels. How this latter escape of water occurs can also be visualized by reference to FIG. 12 A. Thus, by limiting the volume of water in the basin and by allowing the basin to float within the dock 22 , the pool 170 of water effectively maintains the V-shape of the basin without causing the basin to balloon or billow outwardly and downwardly as might occur if the upper edges 56 and 68 of the basin were securely tied by the lines 160 to the cleats 34 . Even if the basin sinks down far enough to place the tethering tie lines 160 under tension, the flotation tubes 140 and 142 have a tendency to yield somewhat and counteract a tendency of the basin to balloon in the water out of its desired shape. Of course, another reason for maintaining the level 172 of the pool 170 below the upper edges of the basin is to isolate the pool 170 from the surrounding sea water.
The downwardly sloping, planar walls 64 and 66 of the basin 42 (FIGS. 3, 6 , 9 , 16 ) of the present invention are to be contrasted with the concave, rounded shape of the walls of the bag of my prior U.S. Pat. No. 5,138,963. As will be described in more detail subsequently, the side walls of the basin of the present invention are sloped at favorable angles directed toward the juncture 74 , which is at the nadir of the bottom of the basin, in order to allow substances that settle on the side walls to gravitate toward the nadir.
The water filtration system 44 (FIGS. 5, 13 , 15 and 17 ) of the subject apparatus 20 includes a pump 200 , a filter 202 , a collector pipe 204 , return piping 206 , an collector hose 208 interconnecting the collector pipe and the pump, and a return hose 210 interconnecting the filter and the return piping. The collector pipe is elongated and perforated having a forward end 216 , an aft end 218 , and provided with a plurality of apertures 220 along its full length from the forward end to the aft end. The length of the collector pipe is approximately the same as the length of the juncture or nadir 74 in the basin 42 and lies along this nadir with the forward end 216 adjacent to the forward end wall 50 and the aft end adjacent to the gate 90 . As positioned in the basin, the apertures of the pipe are directed upwardly and preferably also laterally, as shown in FIG. 5 . The collector pipe may be made of plastic, metal, a composite or other suitable material.
The collector pipe 204 is merely rested in the nadir 24 of the basin 42 but is not attached to the basin. As such, the collector pipe can readily be moved from its operating position in this nadir, as shown in FIGS. 4-6 and 13 - 16 , into a displaced position on one of the side portions 26 of the dock 22 , as shown in FIGS. 1-3. The collector pipe has sufficient weight so that when it is located on and in the nadir of the basin, it remains in that position and helps to hold the basin in its V-shaped or trough configuration, as discussed above. The return piping 206 (FIGS. 5, 13 , 15 and 17 ) includes a forward, floatable manifold 221 having a diameter approximately the same as the collector pipe 204 and floating on the pool 170 of water in the chamber 130 in adjacent spaced relation to the forward end wall 50 of the basin and with its opposite ends in adjacent spaced relation to the upper edges 68 of the side walls 64 and 66 . Elongated floatable lateral return pipes 222 are individually connected by quick connect swivel couplings 224 to the ends of the manifold and have capped aft ends. The manifold and the return pipes are made of PVC flotation pipe so that the return piping readily floats on the surface 172 of the pool 170 . The return pipes are of a diameter less than that of the manifold or the collector pipe and have inwardly and downwardly directed apertures 230 along the entire length of each return pipe. The length of the return pipes is approximately the same as the length of the basin so that the aft ends of the return pipes are adjacent to gate 90 . Also, the length of the manifold is such that the U-shaped return piping fits within the upper portion of the basin 42 with the return pipes in adjacent spaced relation to the side walls 66 and 64 and so that the return piping may float up and down within the basin a limited distance without necessarily resting on the side walls.
With reference to the hydraulic filtration circuit shown in FIG. 17, the collector hose 208 connects the forward end 216 of the collector pipe 204 to the inlet of the pump 200 , and the return hose 210 connects the outlet of the filter 202 to the manifold 221 intermediate the ends thereof. It will thus be understood that with the pump operating, water and water borne contaminants are sucked through the apertures 220 of the collector pipe 204 , drawn by the pump into the filter, and forced by the pump through the filter wherein contaminants are removed from the water. Clean water exits through the return hose into the manifold where it passes into the return pipes and from there through the apertures 230 back into the pool. The apertures in the return pipes are directed downwardly and slightly inwardly over the sloping side walls 64 and 66 and create a gentle downwardly directed current causing the solid materials in suspension in the pool to gravitate downwardly onto the side walls and thence downwardly toward the collector pipe. The apertures 230 in the return pipes are of smaller diameter than the apertures 220 in the collector pipe and are more numerous than the apertures in the collector pipe. Thus clean water is returned to the pool in a gentle shower from each of the return pipes rather than in a higher velocity jet that would emanate from a single return pipe, the later causing turbulence in the water which would counteract the natural tendency of particulants in the pool to gravitate onto the side walls.
Because the both the collector pipe 204 and the return piping 206 are not attached to the basin, they may be readily manually lifted from their operating positions into resting positions on the dock 22 , as illustrated in FIGS. I through 3 . This construction allows the basin to be easily reversed in order to keep both the inside and the outside surfaces of the basin clean. By reversal of the basin is meant to remove the basin from the dock by untying the lines 160 and 270 , turning it inside out so that the surface of the basin that previously faced downwardly in the water will now face upwardly into the chamber. Since there is no outlet cut in the bottom of the basin or associated fitting, as provided in my prior U.S. Pat. No. 5,138,963, and since the pipes 204 and 205 are removable as described, the reversal of the basin is greatly facilitated. As will be understood, the basin is symmetrical irrespective of which surface faces up and, as above noted, has sufficient flexibility to allow it to be turned inside out as it is being reversed, and is light enough to be handled for this purpose. Moreover, this reversal may be accomplished whether the gate 90 is open or closed. Once the basin has been reversed, it is again placed within the dock, tethered thereto by the lines 160 , and both the collector pipe 204 and the return piping 206 are returned to the positions previously described.
OPERATION AND DESCRIPTION OF THE METHOD
As previously indicated, the subject boat maintenance apparatus 20 may be used to clean or otherwise maintain or service various types of boats, but a sailboat 250 is generally shown in FIG. 14 to illustrate how the subject apparatus may be used. Although the apparatus is ideally suited for boat cleaning purposes, other types of service or maintenance may readily be accomplished, such as under-hull or keel inspections or servicing the engine for example. For convenient reference, the boat shown has a bow 252 , a stern 254 , a mast 256 , a hull 258 , a keel 260 , a rudder 262 , and a deck 264 .
Assuming that the basin 42 is suspended and floating within the dock 22 , that both the collector pipe 204 and the return piping 206 are placed in their operating positions, and that the boat 250 is to be cleaned, the gate 90 is opened as seen in FIGS. 1-3, 10 and 13 . In its open position, the gate extends downwardly and rearwardly from the dock, as shown in FIG. 1, and is maintained in this attitude by the negative buoyancy of the flotation tubes 146 in the gate. The boat 250 is then moved into the basin over the open gate without the keel or rudder becoming fouled with the gate or the bottom of the basin since the gate is maintained at an appropriate sloping position below such parts of a boat. After the boat is completely within the basin, the gate is closed by manually handling the sleeved flotation tubes 146 and folding the panels 92 , 94 , and 96 together in the manner previously described. It is to be understood at this point that either the port panel or the starboard panel may be initially brought toward its kitty-corner aft end of the sleeves 80 , although as above described and as shown in FIGS. 10 through 12, the starboard panel is initially folded upwardly.
Assuming that the gate 90 is closed as illustrated in FIGS. 10-12, the corner 116 of the starboard panel 92 is fastened to the kitty-corner aft end 118 of the port sleeve 80 , and the corner 118 of the port panel 94 is fastened to the aft end of the cattycorner starboard sleeve, both by tie lines 270 . As previously mentioned, during the closing of the gate, water escapes as indicated at 182 and 184 thereby to equalize the pressure inside and outside of the basin so as to prevent the capture of water in the pool 170 from causing the basin to billow out of its desired shape. It is to be noted that the presence of the flotation tubes 160 in the sleeves 102 of the port and starboard panels not only assists in closing the gate but also helps to maintain the lateral V-shaped configuration of the basin.
It is here to be noted that the use of the terms “forward” and “aft” may suggest that a boat, such as 250 , must always enter the apparatus 20 with its bow 252 first. It will be understood, however, that a boat may be backed in if so desired since the apparatus 20 will operate the same irrespective of which end of the boat enters the apparatus first.
With the boat 250 floating in the pool 170 of water in the chamber 130 (FIGS. 14 - 16 ), several dimensional relationships are to be noted. Thus, the maximum transverse dimension of the basin 42 between the upper edges 68 is greater than the maximum width of the hull 258 so that port and starboard spaces are provided on opposite sides of the hull, between the hull and the sidewalls 64 and 66 of the basin. Likewise, the length of the basin is longer than the boat so as to provide for minimal aft spaces between the forward end wall 50 and the bow 252 and between the gate 90 and the stern 254 . These port and starboard spaces and the forward space provide room for the return piping 206 to float in the pool around the boat. Still further, the depth of the basin is sufficient to provide space between the keel 258 and the rudder 262 and the collector pipe 204 as well as the nadir 74 of the basin. Working space is thus provided around the boat for divers to operate in the chamber for cleaning the hull of the boat. If additional space is required at a particular location the boat can be moved transversely and longitudinally within the chamber by limited amounts. In this regard and as mentioned above, the principles of the present invention are adaptable to boats of various sizes, that is, the apparatus may be made larger or smaller as desired, although the invention is particularly suited for use with boats from about thirty feet in length to about seventy feet in length.
In this regard, it may be useful to provide the dimensions of a working example of the basin 42 of the present invention in order to gain an appreciation of the sizes here involved. In this example, the length of the sidewalls 64 and 66 laid out is approximately forty-eight feet, and each edge 54 , 56 , 98 and 100 is about eighteen feet, so that the total length of the forward and aft edges 70 and 72 in this example is about thirty feet. In the formed basin, however, the maximum transverse dimension of the basin in this example is about eighteen feet. If the basin is made of the Plastimayd vinyl sheet, the weight of such a basin approximates two-hundred pounds, as previously mentioned.
With the gate 90 closed behind a boat 250 in the chamber 130 (FIGS. 14 - 16 ), a closed fluid system is achieved by the filtration system 44 operating in the pool 170 of water in the chamber 130 . That is, after the boat 250 is within the closed chamber 130 , the filtration system 44 is turned on and a diver or divers enter the pool 170 and are free to move about in order to work on the hull 258 , the keel 260 , the rudder and other parts of the boat accessible to the diver or divers. The divers normally use scrub brushes to clean the hull and other underwater parts of the boat causing the removed materials to enter the water. These materials may include toxics such as lead from paint removed from the hull. The deck 264 of the boat may also be cleaned allowing the dirty water to wash over the sides of the boat into the pool.
Debris removed from the boat 250 (FIGS. 14-16) as well as cleaning materials used above the waterline enter the pool 170 of water and settle onto the side walls 64 and 66 . Because these walls are planar and sloped toward the nadir 74 , the solids and particulates in the water gravitate down these walls toward the collector pipe 204 . There, the water and water borne solids are sucked into the collector pipe through the apertures 220 and are carried by the pump into the filter. The filter removes the contaminants and releases clean water to the manifold 221 and the return pipes 222 . Clean water exits the return pipes in gentle sprays through the apertures 230 onto the upper surface of the pool adjacent to and above the side walls. This gentle downward spray or shower of clean water tends to establish currents causing the suspended materials to gravitate onto the side walls and toward the collector pipe.
The slope of the side walls 64 and 66 (FIGS. 14-16) and the spray of clean water from the return pipes 22 greatly facilitate movement of settling solids toward the collector pipe 204 . Moreover, the reach of the collector pipe throughout the entire length of the basin 42 , that is the length of the nadir 74 , greatly improves the speed and thoroughness of circulation and removal of contaminated water from the pool. This is to be contrasted with my prior U.S. Pat. No. 5,138,963 wherein all of the contaminated water must enter the single outlet from the basin. Since this is a relatively closed system, the pool 170 is isolated from the surrounding sea water 24 so that the water borne contaminants do not enter the surrounding sea water nor even the surrounding air since the substances remain in the water, gravitate into the collector pipe, and are immediately sent into the filter 202 .
After the boat 250 (FIGS. 14-16) has been cleaned or otherwise serviced, the divers exit from the pool 170 , and the filtration system 44 continues to operate in order to clean the water in the pool sufficiently to allow the gate 90 to be opened. Experience shows that after the diver or divers have completed their cleaning operating, the water in the pool is very discolored and may even appear to be black. Before the gate can be opened, therefore, it is necessary to clean this water so that its clarity returns to a normal state of cleanliness. It is here noted that when the divers are in the pool and cleaning the hull, there is considerable turbulence in the water tending to prevent the unwanted solids from gravitating toward the collector pipe 204 . With the divers out of the water and cleaning operation completed, the water in the pool can become more placid, and for thorough cleaning of the pool, it is important that the water in the pool remain in a relatively quiet state. Since it is necessary to continue to operate the filtration system 44 in order to clean the water in the pool, however, the water would remain turbulent if the cleaned return water were merely ejected back into the pool in a strong stream, as in my earlier patent cited above. The subject return piping 206 avoids this problem. That is, the use of the return pipes 222 that feed the returning clean water to the pool in a gentle shower along each side wall 64 and 66 minimizes the turbulence in the water. As a result, not only is the turbulence minimized but the gentle shower of water over the side walls tends to assist in causing solid materials to gravitate toward the collector pipe 204 along the side walls.
Although a preferred embodiment of the present invention has been shown and described, various modifications, substitutions and equivalents may exist without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been disclosed by way of example and not by way of limitation. | An apparatus and method for cleaning a boat in the water without pollution. Included are a floating, water-impervious basin and a filtration system. Included are a floating, water-impervious basin and a filtration system. The basin has side walls sloped downwardly to a nadir spanning substantially the full length of the basin, an opening allowing the surrounding water to enter the basin as well as ingress and egress of boats, and a gate movable into a closed position forming a cleaning chamber in the basin. After a boat is in the chamber, the gate is closed to create a pool of water in the chamber isolated from the surrounding water and in which a boat may float while being cleaned. As the gate is closing behind a boat, it allows water to pass therethrough thereby to facilitate closure, and yet is substantially sealed when closed. The filtration system includes a collector pipe lying submerged in the nadir and a pair of return pipes that float on the water in the basin. The sloped side walls and water exiting from the return pipes facilitate movement of materials resulting from the cleaning operation toward the collector pipe. The filtration system sucks the water-borne materials into the collector pipe, pumps them through a filter, and returns clean water to the basin through the return pipes. The relationship of the pipes and the basin facilitates reversibility of the basin so that its exterior surface may be periodically cleaned. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to an arrangement of fiber optic strands that employs a radial arrangement, which allows a more compact design and adds the ability to define and permit light to emit from the complete perimeter of the arrangement.
BACKGROUND OF THE INVENTION
[0002] There are numerous invents utilizing fiber optic lighting as a panel for illuminating an object.
[0003] Poly-optical Products commercial distributes a product referred to as Two-layer Uniglo® manufactured under U.S. Pat. Nos. 5,312,569 and 5,499,912. The apparatus comprises a backing member, a plurality of fiber optic strands, the strands are adhered to the backing member in a linear, parallel format, and positioned proximate an adjacent strand to manufacture a ribbon type material. The fiber optic strands separate the backing material and are gathered onto a collector. An illumination source, such as an LED is then coupled to the collector by a coupling device providing a means to control the transference of light from the illumination source into the fiber optic strands.
[0004] The light emission has the greatest intensity at the sheared end of each strand. The apparatus is limited in the requirement of an “illumination sourcing tail section” that separates from the backing material and is gathered into a collector. This illumination sourcing tail section can be referred to as a “hot spot” whereby the light intensity is greater and less uniform than the ribbon section. The perimeter of the ribbon can not sheared along the tail section thus limiting the outline of the apparatus as well as the illuminated outline of the apparatus.
[0005] Daniel (U.S. Pat. No. 4,519,017) teaches a light emitting optical fiber assembly that employs a non-woven geometric grid which can be cut or sectioned without losing all light emitting capabilities. FIGS. 2 - 6 illustrate fiber optic materials of continuous strands, using the frame and means of wrapping to create the desired pattern. FIGS. 7 and 8 illustrate the application of placing fibers through apertures within the backing material to create a pattern. Daniel is limited in the same manner as the Poly-Optical product, requiring an illumination sourcing tail section.
[0006] Marsh (U.S. Pat. No. 5,944,416) teaches an ornamental application of light pipes positioned between flexible sheets. Marsh is limited in the same manner as the Poly-Optical product, requiring an illumination sourcing tail section.
[0007] Harrison (U.S. Pat. No. 4,754,372) teaches an illuminable covering of a textile material with at least one lighting source connected to the back of the textile material. Harrison is limited in the same teachings as the above cited arts, wherein Harrison teaches the application of a bundle of light-transmissive fibers to illuminatively couple the fiber optic fibers to the illumination source. Harrison is further limited in the application of the Harrison invention wherein Harrison utilizes the porosity of the textile material to position the ends of the fiber optic strands to provide points of illumination. Harrison is thus limited in that Harrison utilizes the ends of the fiber optic strands for illumination and does not provide a means to illuminate the entire surface area of the material. This is further substantiated within the specification, wherein Harrison describes creating patterns of illumination.
[0008] Fuwausa (U.S. Pat. No. 6,174,075) teaches an illuminated ornamental device, the device using a pliable plastic for transmitting light such as sourced from an LED, formulated for maximum dispersion of light through the unit. Fuwausa is limited in that the object shape is molded, and pliable plastic and of a shape conducive to evenly illuminating the device.
[0009] Each of the above illuminating devices is limited in the ability to freely shape the object. The more desirable, fiber optic material devices are limited by the inclusion of an illumination sourcing tail section. The molded objects are limited by the physics to control the emissions within the shape and size of the molded object. Small objects such as watches, pagers, cell phones, key rings, PDA's, toys, and the like are not conducive to fiber optic panels which include an illumination sourcing tail section. Use in objects, which are manufactured of cloth, are further limited in applications of fiber optic panels that require the illumination sourcing tail section.
[0010] Each of the above taught devices require a coupling device, commonly referred to as a fiber optic ferrule. The fiber optic ferrule gathers the bundle of fiber optic strands of the illumination sourcing tail section and couples the illumination source to the fiber optic light panel.
[0011] A number of lights emitting panels are contained in the prior art that teach lateral emission of light along the length of the fibers. Various methods to disrupt the index of refraction are used and have been in practice for a number of years.
[0012] Daniel (U.S. Pat. No. 4,234,907) teaches a light emitting fabric, utilizing woven optical fibers to provide an illuminated fabric. Daniel utilizes an illumination sourcing tail section to provide illumination to the fabric. Daniel further provides an enhancement of the illumination from the fiber optic strands by introducing small scratches that pierce the outer coating. Daniel is limited in the requirement of the illumination sourcing tail section and by providing a woven pattern, Daniel is limited in the shape of the perimeter of the fabric.
[0013] Levens (U.S. Pat. No. 5,560,700) teaches a light coupler utilizing an array of non-imaging optical microcouplers for collecting sunlight and distributing it within a building. The teachings are limited to a spherical surface. The teachings utilize a hemispherical cone as a means to focus the transfer of light. Levens is limited to a curved surface, requiring the curved shape as a means to focus the illumination from the illumination source to the fiber optic strands.
[0014] Fasanella, et al. (U.S. Pat. No. 6,021,243) teaches a low cost star coupler for use in optical data networks. The star coupler taught comprising a support plate having groves in which polymer optical fibers may be placed and a central aperture. The apparatus is a modular design used to facilitate replacement of fibers. The teaching is limited to an apparatus for coupling fiber optical fibers. The teachings are limited to a coupling apparatus with the apparatus requiring slots and distal proximities between adjacent polymer optic fibers, thus being such that it is incapable of providing illumination such as a backing panel.
[0015] Fasanella, et al. (U.S. Pat. No. 6,058,228) teaches a cost effective side-coupling polymer fiber optics for optical interconnections, whereby the coupler utilizes mirrors comprising a notch and mirrors to transfer the optical signals from one fiber bus to a second fiber bus. Fasanella, et al is limited in the location of the optical source similar to the sourcing of the above devices.
[0016] What is desired is an apparatus, which can provide evenly distributed illuminations and illuminate the entire perimeter.
SUMMARY OF THE INVENTION
[0017] One aspect of the present invention is to provide a fiber optic light panel lacking an illumination source tail section.
[0018] A second aspect of the present invention is to provide a fiber optic light panel whereby the light can be emitted along the entire perimeter of the panel.
[0019] A third aspect of the present invention is to provide an optically coupling an illumination source to a plurality of fiber optic strands positioned about a centralized illumination receiving port, wherein the centralized illumination receiving port is a position within the perimeter of said fiber optic light panel.
[0020] A fourth aspect of the present invention is to provide an aperture within the fiber optic light panel, said aperture is positioned proximate said centralized illumination receiving port.
[0021] A fifth aspect of the present invention is to position the illumination source proximate at least one of said centralized illumination receiving port and said aperture.
[0022] A sixth aspect of the present invention is to provide multiple centralized illumination receiving ports within the perimeter of said fiber optic light panel.
[0023] A seventh aspect of the present invention is to provide multiple apertures respective to said multiple centralized illumination receiving ports.
[0024] An eighth aspect of the present invention is to position multiple illumination sources respective to at least one of multiple centralized illumination receiving ports and multiple apertures.
[0025] A ninth aspect of the present invention is the ability to utilize multiple colors of illumination by positioning differing colors of illumination sources to multiple centralized illumination receiving ports.
[0026] A tenth aspect of the present invention is to provide a light diffuser covering said illumination source and centralized illumination receiving ports to obtain an intensity matching that of the adjacent fiber optic light panel.
[0027] An eleventh aspect of the present invention is the ability to shear the entire perimeter of said fiber optic light panel at any angle between zero and 180 degrees respective to the radial line of the center of the centralized illumination receiving port and the contact point on the perimeter.
[0028] A twelfth aspect of the present invention is the ability to shape the fiber optic light panel into a figurative shape.
[0029] A thirteenth aspect of the present invention is the ability to shape the fiber optic light panel into a figurative shape, the shape comprising the entire outline of said fiber optic light panel.
[0030] A fourteenth aspect of the present invention is the inclusion of a modified surface finish of the fiber optic strands to enhance the intensity of illumination along the length of the fiber optic strand.
[0031] A fifteenth aspect of the present invention is the inclusion of at least one reduced length fiber optic strand, whereby the reduced length fiber optic strand is oriented radially from at least one centralized illumination receiving port to a position distant from the perimeter of said fiber optic light panel providing points of illumination at greater intensity than the surrounding panel.
[0032] A sixteenth aspect of the present invention is the ability to manufacture said fiber optic light panel.
[0033] A seventeenth aspect of the present invention is the placement of the fiber optic strands in a radial orientation.
[0034] An eighteenth aspect of the present invention is the placement of the fiber optic strands through an aperture within a backing material.
[0035] A nineteenth aspect of the present invention is the use of a vacuum to assist in the positioning of the fiber optic strands onto the light panel backing material.
[0036] A twentieth aspect in the positioning of the fiber optic fiber utilizes centrifugal forces to assist in the positioning of the fiber optic strands onto the light panel backing material.
[0037] A twenty-first aspect of the present invention is the use of a shaped placement head to assist in positioning of said fiber optic strands.
[0038] A twenty-second aspect of the present invention is whereby said shaped placement head is of at least one of planar, concave, spherical, conical, or egg shaped, and the like.
[0039] A twenty-third aspect of the present invention is the placement of the fiber optic strands, whereby a first end of the fiber optic strands is positioned adjacent the aperture within the fiber optic light panel.
[0040] A twenty-fourth aspect of the present invention is the shearing of the fiber optic strands adjacent a centralized illumination sourcing position to create an illumination sourcing port proximate said centralized illumination sourcing position.
[0041] A twenty-fifth aspect of the present invention is whereby at least a portion of said centralized illumination exiting ports of the fiber optic strands are sheared prior to said perimeter if said backing member.
[0042] A twenty-sixth aspect of the present invention is the whereby the aperture is reinforced by a pliable grommet.
[0043] A twenty-seventh aspect of the present invention is the ability to provide multiple colors for illumination.
[0044] A twenty-eighth aspect of the present invention is utilization of a flexible material, a rigid material, an opaque material, a translucent material, a non-reflective material, a reflective material, a luminescent material, individually, or in combination as said backing member.
[0045] A twenty-ninth aspect of the present invention is the placement of radially arranged fiber optic strands on both sides of the planar backing member.
[0046] A thirtieth aspect of the present invention is the application of a plurality of layers of radially arranged fiber optic strands to increase the intensity of illumination.
[0047] A thirty-first aspect of the present invention is the use of an adhesive comprising of a luminescent material applied as the adhesive for the plurality of layers of radially arranged fiber optic strands.
[0048] A thirty-second aspect of the present invention is the inclusion of multiple-colored illumination sources, whereby the multiple-colored illumination sources are strategically coupled to specific radially arranged fiber optic strands, the coupling positions such to illuminate the present invention in a multi-colored image.
[0049] A thirty-third aspect of the present invention is the utilization, directly or indirectly, of a natural illumination source such as daylight.
[0050] A thirty-fourth aspect of the present invention is the utilization, directly or indirectly, of a natural illumination source such as daylight, combined with the radially arranged fiber optic strands as a decorative skylight, observatory, and the like.
[0051] A thirty-fifth aspect of the present invention is the inclusion of a diffuser, the diffuser designed to increase thermal dissipation from the illumination source.
[0052] A thirty-sixth aspect of the present invention is the ability to remove the backing material from the radially arranged fiber optic panel, whereby the adhesive between the plurality of fiber optic strands provides the means for supporting the shape of the plurality of fiber optic strands.
[0053] A thirty-seventh aspect of the present invention is the utilization of the radially arranged pattern as a means to index angles for applications such as industrial inspections, and the like.
[0054] A thirty-eighth aspect of the present invention is the application of the radially arranged fiber optic panel within a rotating apparatus, such as a fan, and the like.
[0055] A thirty-ninth aspect of the present invention is the application of a strobing effect for the illumination source optically coupled to the radially arranged fiber optic panel.
[0056] A fortieth aspect of the present invention is the application of multiple layers of radially arranged fiber optic strands in conjunction with multiple centralized illumination receiving positions, whereby the pattern apparatus can present an animated image by synchronously timing the illumination sources. Each specified layer would be coupled to a specified centralized illumination receiving positions, wherein as each illumination source provides illumination, it illuminates a predetermined pattern. As the series of illuminations step through the multiple illuminations, the pattern outputs change, thus animating the radially arranged fiber optic panel.
[0057] A forty-first aspect of the present invention is the application of a radially arranged fiber optic panel within a z-axis, resonating structure, such as an audio speaker.
[0058] A forty-second aspect of the present invention is the application of a colorant such as translucent or luminescent paint, dye, or “ink” to the top surface of the fiber so that decorative, warning, or instructional patterns can be seen.
[0059] A forty-third aspect of the present invention is the application of a solar cell or solar array to power the light source directly or indirectly, or charging of the light power source, thus giving the assembly great mobility.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] [0060]FIG. 1 is an isometric view of a known prior art using a fiber optic ribbon adhered to a backing member.
[0061] [0061]FIG. 2 is an isometric view of a first embodiment as a radially arranged fiber optic light panel representative of the present invention.
[0062] [0062]FIG. 3 is an isometric view of a second embodiment as an ornamental, radially arranged fiber optic light panel representative of the present invention.
[0063] [0063]FIG. 4 is an isometric view of a section of a radially arranged fiber optic light panel illustrating the benefits of the present invention.
[0064] [0064]FIG. 5 illustrates a first phase and state of respective tooling for one embodiment of manufacture of a radially arranged fiber optic light panel.
[0065] [0065]FIG. 6 illustrates a second phase and state of respective tooling for one embodiment of manufacture of a radially arranged fiber optic light panel.
[0066] [0066]FIG. 7 illustrates an alternate embodiment of the first phase and state of respective tooling for an alternate embodiment of manufacture of a radially arranged fiber optic light panel.
[0067] [0067]FIG. 8 is a cross sectional drawing illustrating an installed radially arranged fiber optic light panel, the illustration further comprising a detailed cross sectional drawing illustrating a diffuser.
[0068] [0068]FIG. 9 is an isometric view illustrating a single sided, radially arranged fiber optic light panel, further comprising an illumination source and incorporated into an enclosure.
[0069] [0069]FIG. 10 is a cross sectional drawing illustrating an installed radially arranged fiber optic light panel with radially arranged fiber optic strands positioned on both sides of the backing member.
[0070] [0070]FIG. 11 is a cross sectional view providing a more detailed illustration of a proposed diffuser.
DETAILED DESCRIPTION OF THE INVENTION
[0071] [0071]FIG. 1 is an isometric view of a current, commercially-available, linear fiber optic panel 10 comprising a plurality of fiber optic strands 12 positioned contiguous and parallel one another and adhered to a backing material 14 . The plurality of fiber optic strands 12 are arranged into an illumination sourcing tail section 16 and gathered within an optical coupling member 22 . The ends of the plurality of fiber optic strands 12 are sheared and polished at the illumination-sourcing end 18 of the plurality of fiber optic strands 12 . The illumination source (not shown) would be optically coupled to the illumination sourcing tail section 16 using the optical coupling member 22 ; the light would travel within the plurality of fiber optic strands 12 across the linear fiber optic panel 10 ; and exit at an illumination-exiting end 20 of the plurality of fiber optic strands 12 . The arrangement of the linear fiber optic panel 10 does not allow the shearing of the plurality of fiber optic strands 12 along a linear edge 24 of the linear fiber optic panel 10 . Should the linear edge 24 of the linear fiber optic panel 10 become damaged, the light path will become compromised, thus limiting or no longer transferring the light to the illumination-exiting end 20 .
[0072] [0072]FIG. 2 is an isometric view of a first embodiment of the present invention; a radially arranged fiber optic panel 100 comprising a plurality of radially arranged fiber optic strands 112 positioned radially from at least one centralized illumination receiving position 124 . The fiber optic strands 112 can be of any light transmissive fibers such as plastic optical fiber, glass optical fiber, and the like. The plurality of radially arranged fiber optic strands 112 comprise a first end being an illumination receiving port 126 and a second end being an illumination exiting port 120 . The plurality of radially arranged fiber optic strands 112 are positioned with the centralized illumination receiving port 126 adjacent the at least one centralized illumination receiving position 124 and the illumination exiting port 120 positioned towards a peripheral edge 122 of a radially arranged fiber optic backing member 114 . The plurality of radially arranged fiber optic strands 112 are adhered to said radially arranged fiber optic backing member 114 and adjacent plurality of radially arranged fiber optic strands 112 . The ends of the plurality of fiber optic strands 112 are sheared and polished at the illumination-sourcing end 126 of the plurality of fiber optic strands 112 . The illumination source (not shown) would be optically coupled to the illumination-sourcing end 126 of the plurality of fiber optic strands 112 at said at least one centralized illumination receiving position 124 . The light would travel within the plurality of fiber optic strands 112 across the radially arranged fiber optic panel 100 ; and exit at an illumination-exiting end 120 of the plurality of fiber optic strands 112 . The arrangement of the radially arranged fiber optic panel 100 allows the shearing of the plurality of fiber optic strands 112 along the peripheral edge 122 of the radially arranged fiber optic panel 100 .
[0073] [0073]FIG. 3 is an isometric view of a second embodiment of the present invention; an ornamental, radially arranged fiber optic panel 130 comprising a plurality of radially arranged fiber optic strands 112 positioned radially from at least one centralized illumination receiving position 124 . The plurality of radially arranged fiber optic strands 112 are positioned with a centralized illumination receiving port 126 adjacent the at least one centralized illumination receiving position 124 and an illumination exiting port 120 positioned towards an ornamentally shaped, peripheral edge 132 of a radially arranged fiber optic backing member 114 . The plurality of radially arranged fiber optic strands 112 are adhered to said radially arranged fiber optic backing member 114 and adjacent plurality of radially arranged fiber optic strands 112 . The ends of the plurality of fiber optic strands 112 are sheared and polished at the illumination-sourcing end 126 of the plurality of fiber optic strands 112 . The illumination source (not shown) would be optically coupled to the illumination-sourcing end 126 of the plurality of fiber optic strands 112 at said at least one centralized illumination receiving position 124 . The light would travel within the plurality of fiber optic strands 112 across the ornamental, radially arranged fiber optic panel 130 ; and exit at an illumination-exiting end 120 of the plurality of fiber optic strands 112 . The arrangement of the ornamental, radially arranged fiber optic panel 130 allows the shearing of the plurality of fiber optic strands 112 along the ornamentally shaped, peripheral edge 132 of the an ornamental, radially arranged fiber optic panel 130 .
[0074] The various embodiments can be further enhanced with the inclusion of additional centralized illumination receiving positions 124 to provide for additional sources for illumination. The additional sources can provide a means for applying multiple colors of light to the various embodiments of the present invention. A portion of the plurality of fiber optic strands 112 can be sheared at a position prior to the peripheral edge 122 , 132 of the present invention as a means to increase the intensity of light at positions within the peripheral edge 122 , 132 of the present invention.
[0075] [0075]FIG. 4 illustrates a section of an isometric view of a radially arranged fiber optic panel 100 illustrating the benefit of the present invention. The present invention provides the ability to shape the outline of the radially arranged fiber optic panel 100 in a non-rectangular shape. The radially arranged plurality of fiber optic strands 112 allows the designer to shear the radially arranged fiber optic panel 100 at angles described herein when following the perimeter 122 of the radially arranged fiber optic panel 100 as described in a clockwise direction. The angles described provide the capabilities of the present invention, wherein the actual embodiments reduced to practice may not have the severity of angles as described, while maintaining the same spirit and intention of the present invention. The perimeter 122 can have a first angle θ A shearing the radially arranged fiber optic panel 100 up to 180 degrees (parallel) to the adjacent fiber optic strand 112 towards the at least one centralized illumination receiving position 124 . The perimeter 122 has a second angle θ B shearing the radially arranged fiber optic panel 100 the second angle θ B equal to or greater than 0 degrees and equal to or less than 180 degrees respective to the adjacent fiber optic strand 112 . If the shearing were greater than 180 degrees, the shearing would disunite the continuity of the fiber optic strand 112 , thus limiting the transfer of the illumination at the point of disunity. The perimeter 122 has a third angle θ c shearing the radially arranged fiber optic panel 100 the third angle θ c being up to 180 degrees (parallel) to the adjacent fiber optic strand 112 away from the at least one centralized illumination receiving position 124 . The present invention provides the designer the capability of incorporating angles as described herein and completely circumventing the at least one centralized illumination receiving position 124 . One perfect application of the present invention illustrating the advantage over the prior art would be a round shaped object requiring a back lighting, such as an automotive gauge.
[0076] [0076]FIG. 5 illustrates a first phase in a first embodiment of the steps of manufacture to fabricate the present invention, the first phase being the radial arrangement of a plurality of fiber optic strands 112 . The manufacturing process would include a fiber optic bundle feeding mechanism 140 which directs a predetermined length of fiber optic strands 112 through the at least one centralized illumination receiving position 124 of the fiber optic backing member 114 towards a radially arranging placement head 150 . The radially arranging placement head 150 can comprise of a radially arranging forming member 151 and a vacuum directing member 152 . The radially arranging forming member 151 comprises a placement surface 153 , a compression region 155 and a compression supporting surface 156 . The radially arranging forming member 151 would have a normally non-compressed state providing a normally non-compressed force 154 when the radially arranging forming member 151 is positioned in the radially directing position (as shown). The process can apply a rotational force 144 to the plurality of fiber optic strands 112 to utilize centrifugal force as a means to assist in positioning the plurality of fiber optic strands 112 into the desired radial positions. The fiber optic bundle feeding mechanism 140 can be utilized to apply the rotational force 144 to the plurality of fiber optic strands 112 by shearing the plurality of fiber optic strands 112 , temporarily coupling the plurality of fiber optic strands 112 to the fiber optic bundle feeding mechanism 140 , and rotating the fiber optic bundle feeding mechanism 140 . An adhesive layer 142 can be applied to the fiber optic backing member 114 prior to the positioning of the plurality of fiber optic strands 112 onto the fiber optic backing member 114 . This can expedite the manufacturing process. A vacuum force 160 can be applied to further assist in the radially positioning process, whereby the vacuum force 160 would assist in drawing the plurality of fiber optic strands 112 evenly against the radially arranging forming member 151 .
[0077] [0077]FIG. 6 illustrates a second phase in the first embodiment of the steps of manufacture to fabricate the present invention, the second phase being the positioning of the radially arranged plurality of fiber optic strands 112 onto the fiber optic backing member 114 . The plurality of fiber optic strands 112 are positioned in a radially arranged pattern within the first phase of the manufacturing process. The plurality of fiber optic strands 112 are then positioned onto the fiber optic backing member 114 by bringing the fiber optic backing member 114 and the radially arranging placement head 150 proximate each other. The contacting force (not shown) would overcome the normally non-compressed force ( 154 of FIG. 4) and cause the compression region 155 to collapse as shown. The compression supporting surface 156 would provide support beyond the dimensions provided by the collapse of the compression region 155 . The placement surface 153 would apply a placing force (not illustrated) to position the plurality of fiber optic strands 112 onto the fiber optic backing member 114 . Bonding between the plurality of fiber optic strands 112 and the fiber optic backing member 114 can be completed by any of commonly known means, including, but not limited to pre-applied adhesives, spray adhesives, liquid adhesives, heating, and ultrasonic welding. The vacuum force 160 can optionally be continuously applied to assist in maintaining a radial arrangement of the plurality of fiber optic strands 112 against the placement surface 153 . Upon completion of the bonding process, a shearing mechanism 162 would shear, and preferably polish, the plurality of fiber optic strands 112 . One alternative shearing mechanism 162 would be a punching process, whereby the shearing mechanism 162 vertically shears the plurality of fiber optic strands 112 proximate the at least one centralized illumination receiving position 124 . The final phase of the manufacturing process (not illustrated) would be shaping the radially arranged fiber optic panel 100 by shearing the radially arranged fiber optic panel 100 . One means of accomplishing this is using a steel rule die shearing apparatus.
[0078] The illumination exiting ports ( 120 of FIG. 2) provide a greater intensity of light compared to the intensity of light emitted along the length of the fiber optic strands 112 . The plurality of fiber optic strands 112 can be applied to the fiber optic backing member 114 in several repeated steps, whereby the lengths can be varied. The varied lengths (as shown) positions the illumination exiting ports 120 across the radially arranged fiber optic panel 100 , as opposed to only being along the sheared edge(s).
[0079] [0079]FIG. 7 illustrates an alternate embodiment of the first phase of manufacturing of the radially arranged fiber optic panel 100 . The alternate first phase would comprise the same members as described as within the first embodiment above, with the addition of an air flow, radially position assistance port 180 . The air flow, radially position assistance port 180 would provide air flow 182 directed towards the center of the plurality of fiber optic strands 112 fed from the fiber optic bundle feeding mechanism 140 . The air flow 182 would assist in positioning the plurality of fiber optic strands 112 into a radial position as shown. The air flow, radially position assistance port 180 can be elastically coupled to the radially arranging placement head 150 wherein the air flow, radially position assistance port 180 can elastically adjust vertically to modify the position of the air flow, radially position assistance port 180 respective to the placement surface 153 of the radially arranging forming member 151 . During the first phase of manufacture, the air flow, radially position assistance port 180 can be positioned protruding from the placement surface 153 towards the fiber optic bundle feeding mechanism 140 . During the second phase of manufacture, the air flow, radially position assistance port 180 can be positioned proximate the placement surface 153 . One means to accomplish this would be to place a compliant member such as rubber, a spring, and the like, at least one of coupled to and behind the air flow, radially position assistance port 180 .
[0080] An alternate embodiment would be to utilize electro-static charge to assist in positioning the plurality of fiber optic strands 112 into a radial position. The manufacturing apparatus can apply a charge to the plurality of fiber optic strands 112 , preferably at the fiber optic bundle feeding mechanism 140 . An electro-static charge, with a polarity opposing the charge applied to the plurality of fiber optic strands 112 , would be discharged by a member positioned similar to the air flow, radially position assistance port 180 illustrated. The opposing charges would assist in positioning the plurality of fiber optic strands 112 into a radial position.
[0081] [0081]FIG. 8 illustrates the radially arranged fiber optic panel 100 incorporated within a proposed application. The radially arranged fiber optic panel 100 would be positioned with the centralized illumination receiving position 124 proximate an illumination source 204 . The illustration presents a Printed Circuit Assembly 200 , the Printed Circuit Assembly 200 comprising a Printed Circuit Board 202 , a respective illumination source driving circuit (not shown), and the illumination source 204 . The illumination source 204 would be optically coupled with the centralized illumination receiving port 126 of each of the plurality of fiber optic strands 112 . A light diffuser 170 can be coupled to the assembly proximate the illumination source 204 . It would be preferred that the light diffuser 170 be of a material, transparency, and/or coloration which illuminates to an intensity and colorization similar to that emitted by the plurality of fiber optic strands 112 of the radially arranged fiber optic panel 100 . The present invention can be furthered by the inclusion of a plurality of illumination sources 204 . The present invention can be furthered wherein the illumination source(s) 204 can emit multiple colors. A first means of accomplishing multiple colors can be accomplished by providing a plurality of illumination sources 204 , whereby at least one of the illumination sources 204 illuminates a first color and at least a second of the illumination sources 204 illuminates a second color. A second means of accomplishing multiple colors can be accomplished by providing at least one of illumination source 204 , whereby the least one of illumination source 204 is capable of illuminating in multiple colors. One such available illumination source 204 would be a bi-color LED. A third means of providing multiple colors to the illumination source 204 is by including a color wheel (not shown), the color wheel being a color-tinted, translucent material positioned between the illumination source 204 and the plurality of fiber optic strands 112 . The color wheel can be coupled in a manner providing the ability to change in position respective to the illumination source 204 . If the color wheel comprises multiple colors, the color can be changed by changing the position of the color wheel respective to the illumination source 204 .
[0082] [0082]FIG. 9 illustrates an isometric view of the radially arranged fiber optic panel 100 incorporated within a proposed application as one embodiment of an end product. The embodiment shown is representative of the first reduction to practice achieved by the inventors. The illustrated embodiment comprises the radially arranged fiber optic panel 100 , a Printed Circuit Assembly 200 , the Printed Circuit Assembly 200 comprising a Printed Circuit Board 202 , a respective illumination source driving circuit (not shown), and the illumination source 204 . The radially arranged fiber optic panel 100 and Printed Circuit Assembly 200 are coupled to an enclosure 220 (shown as a cutaway section). The illumination source 204 provides illumination to the plurality of fiber optic strands 112 . The plurality of fiber optic strands 112 distribute the illumination radially whereby the illumination is emitted through the external surface of the fiber optic strands 112 . The distribution of the plurality of fiber optic strands 112 provides illumination across the entire surface area of the radially arranged fiber optic panel 100 , illuminating the enclosure 220 . A light diffuser 170 can be integrated within the enclosure 220 . Additional illumination can be provided from the illumination exiting ports 120 . Features can be provided within the enclosure to direct the illumination from the illumination exiting ports 120 across the surface area of the enclosure 220 . The surface of the enclosure 220 can be textured to change the intensity of the illumination. The enclosure can be manufactured to become more appealing, including such features as colored materials, variations in transparency, images molded within the enclosure, and other known molding processes. The apparatus can include variations for providing color(s) to the illumination. Some examples of applications include, but are not limited to: key chain, Christmas, and other ornaments (first reduction to practice), picture frames, fabric and clothing, art pieces, cell phones, pagers, computers, personal data assistants, automotive accessories, sporting goods, medical devices, musical instruments, training mechanisms, pins, toys (Frisbee, tops, Yo-Yo's, etc.) signs, cards (business, greeting, playing, etc.), trophies and plaques, accent lighting, and timepiece (watch, clock, etc.).
[0083] [0083]FIG. 10 illustrates an installed, encapsulating radially arranged fiber optic light panel 206 with a plurality of radially arranged fiber optic strands 112 positioned on two opposing sides of an encapsulating backing member 222 . The encapsulating radially arranged fiber optic light panel 206 comprises an illumination sourcing compartment 224 positioned either between two backing members ( 114 of FIG. 8) or within the encapsulating backing member 222 . The plurality of radially arranged fiber optic strands 112 can be coupled to one or both sides of the encapsulating backing member 222 . The application can provide two (or more) illumination sources 204 as shown to provide illumination to the plurality of radially arranged fiber optic strands 112 . A Printed Circuit Assembly 200 , the Printed Circuit Assembly 200 comprising a Printed Circuit Board 202 , a respective illumination source driving circuit (not shown), and the illumination source 204 is shown as a means for providing illumination to the encapsulating radially arranged fiber optic light panel 206 . The Printed Circuit Assembly 200 can be double sided to provide the illumination source 204 to both sides of the encapsulating radially arranged fiber optic light panel 206 . Alternatively, the illumination source 204 can be positioned proximate the at least one centralized illumination receiving position 124 . The illumination source 204 can be powered by any remote means such as a circuit comprising a power source, wires, and a switch.
[0084] [0084]FIG. 11 illustrates a more detailed view of two diffuser concepts. The diffuser 170 can be positioned above the illumination source 204 and coupled to the radially arranged fiber optic panel 100 . The diffuser 170 can be of any material, but preferably the material would be of a translucence providing an intensity that is comparable to that of the adjacent fiber optic strands. If the design is such that the illumination at the diffuser 170 is not desired, the diffuser 170 can comprise a reflective material to assist in directing the illumination towards the illumination receiving port 126 . An illumination backing diffuser 224 can be incorporated, the illumination backing diffuser 224 providing a means to direct the illumination towards the illumination receiving port 126 . The illumination backing diffuser 224 can be used to couple the illumination source 204 to the radially arranged fiber optic panel 100 . One means of accomplishing this would be a friction fit between the illumination backing diffuser 224 and the aperture respective to the centralized illumination receiving position 124 . The illumination source 204 is shown including a conductor 226 which can be a wire. The conductor 226 would be electro-mechanically coupled to a power source (not shown). The illumination backing diffuser 224 can include a reflective material to assist as a means to direct the illumination towards the illumination receiving port 126 .
[0085] Applications: It can be recognized that the fiber optic backing member 114 can be of a flexible material, preferably woven, a rigid material, an opaque material, a translucent material, a non-reflective material, and a reflective material. This provides a material whereby the end user can couple multiple sections for applications that can be considered “illuminating fabric” for items such as clothing, hats, accessories, and the like. The planar nature of the radially arranged fiber optic panel 100 provides an apparatus whereby the user can create illuminating shapes that can be assembled into ornamental housings, adhered to glass for decorative applications, etc.
[0086] Additional applications of the present invention would be: illuminated Pavers™ for lawn, driveway and gardens; dishes and cups, buttons, and emblems for clothing and hats; home and office lighted novelties; furniture; outdoor lighting; targets; standard lighting replacements; airport lighting; night-lights; map-readers; and UFO models. | An apparatus and method of manufacture is disclosed for a fiber optic lighting device. The fiber optic lighting device is formed by adhering fiber optic strands onto a backing material in a radial pattern from a centralized illumination receiving port within a perimeter of the backing material. The centralized illumination receiving port of the fiber optic strands is where the illuminating source would transfer the illuminations into the fiber optic strands. The fiber optic strands can include a surface finish, which enhances the intensity of the light emitting from the fiber optic strands. The fiber optic lighting device can provide a non-linear sheared edge along the entire perimeter of the backing material. | 8 |
INTRODUCTION
[0001] This invention relates to a diamond compact body comprising diamond particles bonded together by a silicon-containing binder or bonding phase. Such compacts are well-known in the art and are useful as an abrasive, cutting tool, nozzle or other wear-resistant part. The invention extends to a method of manufacturing such a diamond compact body.
BACKGROUND OF THE INVENTION
[0002] Diamond is the hardest material known to man. Because of this, it finds extensive industrial application where ultra-hard material properties are needed. Due to its high hardness, it is difficult to make diamond tools of different shapes and sizes purely from cutting and shaping diamond. This has led to the development of diamond composite materials which consist of small diamond grains either sintered together through a liquid phase sintering process, or held together in a matrix by a binder phase material. The former process gives rise to the class of polycrystalline diamond materials (PCD), while the latter results in a number of composite materials, of which the foremost is that of SiC-diamond composites. The introduction of the second phase improves the formability and the fracture toughness of such diamond-based material.
[0003] Metallic phases such as cobalt are present in PCD and are commonly used as liquid phase sintering aids in the production of that material. These metals however were found to catalyse the graphitization of diamond thus limiting the application temperatures of these PCD materials to below 1000° C. Silicon carbide has been found to be exceptionally good as a diamond binder phase. Because of the structural similarities between diamond and silicon carbide, a strong bond forms between them that results in a material with very strong adhesion between the diamond grains and the SiC matrix. SiC is commonly formed in situ from the reaction between diamond and/or amorphous carbon or graphite with silicon. SIC does not react with diamond and hence the composite material can be used at temperatures above 1000° C. However, the application temperature may be limited by the melting temperature of silicon if some unreacted silicon is present in the final product.
[0004] There are two different generic routes of production of these composites:
mixing of a powdered silicon source with diamond particles and densification of the mixture under pressure with temperature (reaction sintering), or infiltration by a silicon-containing melt of a preform made from diamond powder or from mixtures of diamond with graphite or resin.
[0007] Reaction sintering to obtain fully dense compacts is only relatively straightforward under the high-pressure high-temperature (HpHT) conditions typically associated with diamond synthesis. Under low pressure conditions (such as Hot Pressing (HP) and Hot Isostatic Pressing (HIP)), the volume decrease associated with the local formation of SiC from the intermingled silicon source and diamond may well result in residual porosity. Therefore a pressure high enough for densification of the reacted compact such as diamond stable conditions can be necessary. This requirement for high or ultra high pressure limits the application of these materials due to production costs and the limited sizes and shapes accessible with this technique.
[0008] On the other hand, infiltration has been successfully utilised in generating fully dense composites even at low pressure conditions. This is explained by the fact that even if/as pores are generated within the structure during sintering, liquid phase is continuously wicked up from the infiltrant source to fill these pores. Effective infiltration therefore requires that the pores or channels in the preform structure remain open for infiltration. The limitation imposed by this pore size and density requirement means that infiltration has been chiefly employed for the manufacture of larger-grained diamond compacts, or those with a wide diamond grain size distribution. Even under HpHT conditions (7.7 GPa, 1400-2000° C.), infiltration of diamond powder with primary grain size of ˜10 nm but secondary particle (agglomerate) size of approximately 1 μm was only possible to a depth of 2 mm.
[0009] This pore retention problem is exacerbated by the ongoing formation of SiC within the preform. SiC formation from the interaction of molten Si infiltrant and the carbon source is accompanied by volume expansion of the solid phase. This reduces the size of the existing pore channels and can result in blockage thereof. This especially becomes a matter of concern for fine-grained preforms, which already have an extremely fine pore structure. An additional concern is that the formation of SiC is strongly exothermic, which further accelerates the reaction in a runaway effect.
[0010] Infiltration has a further advantage in that the purity of the silicon source can be more adequately controlled through the use, for example, of a monolithic silicon wafer. By contrast, a reaction sintering or admixing technique typically requires that a very fine powder be used in order to maximise microstructural homogeneity. This brings with it the associated impurities of high surface area particles, as well as concomitant contamination introduced during the preparative mixing or milling process.
[0011] A further issue in the generation of diamond-SiC compacts relates to the presence of free or elemental silicon in the final binder phase. The thermal stability of a compact containing discernible free silicon may be limited by the melting point of silicon, as the bond between diamond and binder phase can be compromised at this point. Typically the presence of free silicon is the mark of an incomplete reaction with the carbon source. This may occur where substantial SiC formation has masked or blocked off the silicon melt from carbonaceous material, as diffusion of these species through SiC is significantly slower than that along the grain boundaries
[0012] U.S. Pat. No. 4,124,401 describes a diamond compact comprising a mass of diamond crystals adherently bonded together by a silicon atom-containing binder. The compact is made by infiltration under relatively mild hot pressing conditions (<1 kbar), where pressure is applied to dimensionally stabilise the diamond mass before and during infiltration. The resultant binder comprises SiC and a further carbide and/or silicide of a metal component which forms a silicide with silicon. The diamond density of the compact ranges from 70-90 volume %. The metal component for the diamond body is selected from a wide group of metals such as cobalt, chromium, iron etc.
[0013] U.S. Pat. No. 4,151,686 describes a diamond compact similar to that of U.S. Pat. No. 4,124,401 save that the resultant binder comprises SiC and elemental or free silicon. The substantially pore-free compact is generated at significantly higher pressures (in excess of 25 kbar) through infiltration by an elemental silicon melt. These high pressures are required in order to achieve the characteristic high diamond density of the compact (from 80-95 volume %).
[0014] U.S. Pat. No. 4,664,705 discloses a method that infiltrates a silicon alloy through a previously intergrown polycrystalline diamond body, that was initially sintered in the presence of a transition metal solvent/catalyst, where this previous binder has been leached out. SiC forms in situ through the reaction of the molten silicon with the intergrown diamond at HpHT.
[0015] U.S. Pat. No. 6,939,506 and U.S. Pat. No. 7,060,641 describe the manufacture of fully dense diamond-SiC composites by reaction sintering at HpHT conditions (namely 5 GPa and temperatures between 600-2000° C.). The reagent mix is prepared by reactive ball-milling of diamond powder (5-10 μm particle size) and crystalline silicon powder. At higher sintering temperatures, the SiC binder that forms is nanocrystalline in nature; whilst at lower temperatures residual unreacted elemental silicon tends to remain in the binder phase. These compacts had a minimum possible calculated diamond content of 77 mass %. It was observed that ball-milling serves to transform the silicon to the amorphous state, which was critical in determining the nanocrystalline nature of the binder.
[0016] Another approach to the formation of SiC-diamond compacts is disclosed in U.S. Pat. No. 5,010,043 and associated applications. In a specific embodiment of this process, reaction sintering of a diamond-silicon mixture is employed together with silicon melt infiltration to form diamond-SiC compacts with a diamond density of 50-85 volume %. The silicon admixed within the compacts is postulated to melt and wet the surfaces of the diamond particles, establishing a continuous capillary system for infiltration. The compact formation conditions are intermediate between conventional HpHT and low pressure processes, at 10-40 kbar. Critical to this process is a deliberate plastic deformation step that is observed to significantly improve the properties of the resultant compacts and enable the use of p and T conditions reduced from those of HpHT. Given that it is known in the art that plastically deformed diamond is inherently more reactive than diamond which is not (see U.S. Pat. No. 6,680,914), it may be the case that the improved reactivity of the diamond in this invention is what enables effective bonding at lower p, T conditions. This is consistent with the fact that manipulation of the sintering temperatures generates compacts that contain minimal amounts of free silicon in the binder phase, as the SIC formation reaction has been maximised.
[0017] It is also known in the art to produce diamond-SiC compacts where the carbon source for the in situ SiC formation is not dominantly supplied by crystalline diamond but by a carbon introduced or produced on the diamond surface. Both low and higher pressure techniques employing this approach are known.
[0018] U.S. Pat. Nos. 4,220,455 and 4,353,953 describe diamond-SiC compacts formed by coating diamond particles with amorphous carbon before infiltrating under partial vacuum with molten silicon. The amorphous carbon is introduced by pyrolysis of organic binder systems such as resins, polymers etc., or by pyrolytic decomposition of carbonaceous gases. An advantage of the resin or polymer approach is that the organic residue can facilitate formability of the pre-sintered diamond. It was additionally observed that non-diamond carbon coatings were highly reactive in the presence of molten silicon, easily wet by it and hence easily formed SiC. However, the binder phase in these compacts still comprised both SiC and unreacted elemental silicon.
[0019] U.S. Pat. No. 4,381,271 employs carbonaceous materials such as fibrous graphite as an additional carbon source for SiC formation. These fibres are admixed with coated diamond particles before being infiltrated by molten silicon under a partial vacuum. In the final compact binder both SiC and unreacted elemental silicon were observed.
[0020] In most of these cases, any required pyrolysis is carried out to minimise the graphitisation of the diamond; as this is seen as detrimental to the potential properties of the compact. By contrast, U.S. Pat. No. 6,447,852 and associated applications disclose a low pressure infiltration process for the manufacture of diamond-SiC compacts that utilises a deliberate graphitisation step. Preferably 6-30 mass % of the diamond is deliberately graphitised prior to infiltration with molten silicon. It is postulated that the graphitised layer on the diamond surface affects the pore character such that an optimal infiltration environment results. A characteristic of compacts of this invention is the discernible presence of free silicon in the binder phase.
[0021] Infiltration remains a preferred method for the manufacture of diamond-SiC compacts because of the opportunity it provides for exploiting low pressure processes. There are significant cost benefits inherent in this approach over using HpHT; and further benefits of being able to access shapes and sizes not viably attainable in HpHT or even medium pressure processes. However, the use of infiltration for finer-grained diamond structures is problematic because of the fine-scale nature of the pore structure and the ease with which these pores can be blocked. Nonetheless, finer-grained structures would be of great interest as high performance composites. Additionally, the generation of a compact containing no discernible free silicon that uses a low pressure infiltration process would have significant cost and technical benefits.
SUMMARY OF THE INVENTION
[0022] According to a first aspect to the present invention there is provided an abrasive compact comprising a mass of diamond particles and a silicon containing binder phase wherein the diamond particles are present in an amount less than 75 volume % and the binder phase contains less than 5 volume % unreacted (elemental) silicon or silicide. Preferably the diamond particles are present in an amount of more than 5, more preferably 10, and most preferably 20 volume %; but less than 75, more preferably less than 70 volume %. The compact binder phase is characterised in that, whilst it is dominated by a silicon-based chemistry, preferably there is no detectable free or elemental silicon present in the binder system and the majority of silicon present in the binder phase is silicon carbide SiC. Preferably the SiC in the binder phase is microcrystalline in nature. Preferably the diamond particles are not plastically deformed to a significant degree and the particles typically have an average grain size less than 10 μm, more preferably less than 7 μm and most preferably less than 5 μm. (Average grain size is measured using the largest diameter of each grain or particle.)
[0023] Silicide results from the reaction of silicon with impurities such as iron, etc.
[0024] Preferably the binder phase of the compact contains less than about 4 volume % unreacted silicon, more preferably less than about 3 volume % unreacted silicon, more preferably less than about 2 volume % unreacted silicon, most preferably less than about 1 volume % unreacted silicon.
[0025] Preferably the unreacted silicon content is within the range of 0 to 5 volume %.
[0026] Still further according to the invention there is provided a method of producing an abrasive compact including the steps of:
a. forming a feed diamond powder into a diamond preform, b. interposing a separating mechanism between the diamond preform and a silicon infiltrant source c. heating the diamond preform and the silicon infiltrant source until the infiltrant is molten and the preform and infiltrant are isothermal, and d. allowing infiltration from the molten silicon infiltrant source to occur into the diamond preform.
[0031] Preferably the infiltration takes place with the application of mild pressure (<1 kbar). More preferably infiltration takes place while simultaneously removing the separating mechanism.
[0032] Preferably the feed diamond powder is coated with a typically amorphous carbon layer through pyrolysis of an appropriate organic binder. The compact may be a compact as hereinbefore described.
[0033] SiC-diamond with low Si or other soft phases, preferably none is suitable for armour applications (stopping high velocity projectiles). As such, according to a third aspect to the present invention there is provided armour comprising an abrasive compact as hereinbefore described.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In the following description, reference will be made to the following Figures:
[0035] Figure A shows an example infiltration process embodiment, and
[0036] Figure B shows the pore size distributions for diamond preforms made from a diamond powder with an average particle size of 1.5 μm with three different initial contents of phenolic resin. D2Pr05 shows the pore distribution at 5 mass % resin, D2Pr10 at 10 mass % and D2Pr20 at 20 mass %.
[0037] Compacts according to the present invention are typically fine-grained diamond-SIC compacts (where the average diamond grain size is typically less than 10 μm) produced through infiltration of a diamond preform by molten silicon-containing materials. These compacts are unique in that they are free of detectable elemental or free silicon in the final binder microstructure. Further, the diamond in these compacts shows no significant plastic deformation. The compacts of the invention further have a high relative diamond density.
[0038] Compacts of the invention comprise a mass of diamond particles distributed in a binder or binding phase. These diamond particles will typically be uniformly distributed throughout the binder phase. In order to achieve a suitable structure, it has been found necessary for the diamond particles to be present in an amount of more than 20, more preferably 30, and most preferably 40 volume %; but less than 75, more preferably less than 70 volume % in the body. The diamond particles may be of natural or synthetic origin. Diamond particles used in a preferred embodiment of this invention have an average grain size less than 10 μm, more preferably less than 7 μm and most preferably less than 5 μm. However, it is observed that many of the advantages of this invention can also be realised where the diamond grain size is coarser than in the preferred embodiment. The diamond particles may have a monomodal, bimodal or multimodal size distribution.
[0039] The binder or bonding phase is dominated by a silicon-based chemistry, however, there is less than 2% volume of detectable free or elemental silicon or silicides present in the binder system of the final compact and most preferably there is no detectable free or elemental silicon present in the binder system of the final compact. Typically the method used to detect free silicon is XRD (X-ray diffraction). The binder typically comprises microcrystalline SiC, although other silicon-based chemistries may also occur. The silicon-based source for the infiltrant may be elemental silicon or a suitable silicon alloy—if elemental silicon, it may be in powder or monolithic form.
[0040] The compacts of the invention are manufactured using temperatures that ensure that the infiltrant is molten, for example in excess of the melting point of silicon (at approximately 1420° C.); and extremely mild pressures less than 1 kbar. Hence the manufacture process is characterised in that it occurs in the thermodynamic region where diamond is metastable. These conditions will be maintained for a time sufficient to produce the abrasive body.
[0041] Preforms for the compacts according to this invention are generated by initially coating the diamond feed diamond powder with a suitable organic binder. In one embodiment of this invention phenolic resin is used as the organic binder, although it will be appreciated that other suitable binders may be used. Appropriate levels for the initial coating are between 5 and 20 mass %, more preferably about 10 mass %. The coated powder is then formed into a green compact by cold compaction. The pore size and pore diameters are controlled either by varying the compaction pressure on the non-pyrolysed resin-diamond preform, or by varying the amount of resin used The green compact is then heat-treated to pyrolyse the organic coating on the diamond powder compact under an inert atmosphere (at temperature conditions where graphitisation of the diamond will not occur). The green compacts generated by this method retain sufficient structural integrity to be handled easily and assembled into the infiltration assembly for subsequent heat-treatment.
[0042] The preform is then infiltrated with molten silicon or a silicon-containing alloy. The preform is placed into a suitable reaction container in proximity to a silicon source, with an appropriate separating mechanism being interposed between the diamond preform and silicon source to space the diamond preform and silicon source from each other. The container is heated to a temperature in excess of the melting point of the silicon (approximately 1420° C.) or the silicon alloy; until the diamond preform and silicon source are isothermal, and the silicon source is molten. Gentle pressure (approximately 20 MPa) is then applied in order to bring the preform and melt into physical contact with one another and hence initiate infiltration. Sufficient time is allowed for effective infiltration to occur and then the container is optionally cooled.
[0043] The infiltrated compact is then removed from the container and processed appropriately to achieve a suitable final product.
[0044] The introduction of a suitable pyrolysed carbon layer onto the surface of the diamond powder is preferable. Without being limited by theory, it is assumed that the increased reactivity of the amorphous carbon generated by the pyrolysis may allow rapid initial SiC phase nucleation on the diamond/carbon surfaces during initial infiltration. Counter-intuitively, this rapid nucleation process appears to result in the formation of a controlled thin SiC layer that effectively acts as a pseudo-barrier to the subsequent diffusion of reactant species. Hence subsequent SiC growth can be somewhat slowed and the potential runaway SiC formation which results in pore blockage in fine-grained structures controlled. As previously discussed, the carbon source in a similar low/no pressure process (such as that disclosed in U.S. Pat. No. 6,447,852 and associated applications) arises from graphitic layers generated in situ from deliberate graphitisation of the diamond powder. This graphite layer, whilst more soluble and reactive than the diamond itself is substantially less reactive than the amorphous carbon layer of this invention. Hence the slower SIC formation in the initial stages does not effectively mask the diamond surface and prevent runaway SiC formation, leading to an increased probability of pore blockage resulting in ineffective infiltration.
[0045] Also, the introduction of sacrificial non-diamond carbon supplies the molten silicon with a non-diamond reactant, thus sparing the valuable diamond phase from conversion into the softer SiC one. Furthermore, and very importantly, the introduction of a non-diamond carbon layer on the diamond particles results in an increase of the pore size of the pyrolised diamond preform, as shown in Figure B, thus providing the infiltrating silicon with an easier passage. In the green compact, most of the carbon-supplying resin occupies the pores of the diamond preform during initial compaction. Therefore, the resulting non-diamond carbon that is generated after pyrolysis is located in the diamond preform pores, thus allowing for the diamond volume fraction to remain relatively high while still supplying the advancing molten silicon front with a carbon reactant.
[0046] Appropriate selection of the organic binder, required additive levels and suitable pyrolysis cycle requires an understanding of the yield and distribution of the amorphous carbon layer that is generated. Whilst the preferred organic agent of this invention is phenolic resin, it is anticipated that the use of other similar organic materials would be self-evident to those skilled in the art such as paraffin, polysaccharides acrylates etc. The organic binder is additionally useful in that it allows the generation of a pressed green compact that has some strength i.e. can be freely handled and machined. The organic binder of the preferred embodiment is typically introduced into the diamond powder mix in dissolved form in a suitable organic solvent such as acetone. Alternative solution methods such as spraying, or gaseous techniques such as the in situ decomposition of a natural gas on the diamond surface would equally be obvious to those skilled in the art.
[0047] Unfortunately, the engineered increased reactivity of the coated fine diamond was observed to result in a premature reaction in the contact region between the preform surface and the silicon infiltrant, whilst the latter was still in the solid state during the heating cycle. This reaction was seen as highly undesirable because the early generation of SIC in this region would easily block the very fine pore structure of a fine-grained diamond preform, resulting itself in incomplete infiltration. This phenomenon was further exacerbated by the increased viscosity of the infiltrant during the early stages of infiltration before it was fully molten. Any drop in temperature from the infiltrant source to the diamond preform was also found to be extremely disadvantageous, as cooling of the infiltrant within the preform had a similar disruptive effect.
[0048] The identified problem was therefore to prevent a premature reaction at the interface between the diamond preform and silicon source whilst it was still in the solid state; and to ensure that the diamond preform and molten silicon source were isothermal before they were brought in contact. Any separation mechanism additionally required the facility to be triggered remotely in situ during the sintering cycle.
[0049] A set of SIC, SiC-based ceramic foam or graphite felt spacers (stilts) was designed to fit into the interface region between the silicon source and diamond preform. The dimensions of these spacers were chosen such that they did not create a physical barrier per se between the two parts, but interposed a space between them. Hence and by way of example, in the case of an 18 mm diameter preform, three SiC spacers of approximately 2 mm×2 mm×3 mm were used to separate the preform and silicon source. These spacers functioned as effective stilts, maintaining separation between the two parts until, once the silicon source was molten; the application of external pressure forced them down into the molten silicon source and allowed contact. The “stilt” spacers must be of such a material that they remain solid during the course of the reaction and are chemically inert with respect to the infiltration reaction. In addition to the above the “stilts” can also be silicon-infiltrated silicon carbide or recrystalised silicon.
[0050] The combined effect of the pyrolytic carbon layer in increasing reactivity, coupled with a pore maintenance; and the physical separation of the infiltrant and preform until infiltration conditions are optimal, allows diamond-SiC compacts with various unique characteristics, namely:
the elimination of free silicon in the binder phase the effective infiltration of finer-grained diamond preforms increased diamond density over that achieved with known low pressure infiltration routes due to the use of a non-diamond source for at least a part of the SiC formation.
[0054] Essentially, when the diamond content in a compact is high, the likelihood and content of elemental Si being present in the finished article is greatly reduced for the following reasons:
Where the diamond content is high, and especially where the grains are fine, higher pressures are typically required in order to compact the material sufficiently and drive infiltration. Higher pressures may have the benefit of driving the diffusion of Si and C and promoting the reaction to form SiC; Where the diamond content is high, the pores may typically be relatively smaller, resulting in smaller isolated volumes of unreacted, free Si. The present invention teaches low or no Si even where the diamond concentration is relatively low and/or the diamond is relatively fine.
[0058] The invention is further illustrated by the following non-limiting examples:
Example 1
[0059] A preform containing diamond powder (average grain size of 1.5 μm) coated with a pyrolytic carbon layer was prepared.
[0060] An amount of phenolic resin to give 10 mass % in the diamond mix, was dissolved in acetone at a concentration of approximately 34.3 g/l. This solution was then mixed with the diamond powder and heated in a water bath to 70-80° C., whilst stirring, to evaporate off the acetone. The resulting agglomerated powder was crushed and screened using a −325 mesh screen. SEM micrographs of the coated grit showed that the resin was homogeneously distributed on the diamond surfaces, both before and after pyrolysis
[0061] A green compact was then formed by cold compaction of the screened powder at ca. 60 MPa. This green compact was then heat-treated at 120° C. in air for 18 hours, in order to cure the resin. The resin coating on the diamond was then pyrolysed by heat treatment under argon. The heating upramp cycle was in two parts: initially up to 450° C. at 2° C./min; followed by heating to 750° C. at 10° C./min. The preform was then held at 750° C. for 1 hour. After cooling, the porosity of the preform was determined to be approximately 30%. From the weight loss it was evident that about half the mass of the resin had volatilised and left the compact.
[0062] The preform was then infiltrated with molten silicon under very mild pressure.
[0063] A silicon infiltrant source body 5 was placed inside an hBN-coated graphite pot 2 such as that shown in Figure A. Three SiC separating spacers 4 (of dimension such that they served a “stilt” function as previously discussed) were placed on top of this source 5 . The diamond preform 3 was then placed in the pot 2 . An hBN-coated graphite piston 1 was then inserted into the pot 2 . The pot 2 was heated to 1500° C. at a rate of 50° C./min. Once the temperature inside the container reasonably exceeded the melting point of silicon (±1420° C.), a pressure of 20 MPa was applied to the piston 1 . This brought the preform 3 and molten infiltrant 5 into contact, commencing the infiltration process. The temperature was held at 1500° C. for approximately 30 minutes before cooling. (Pressure was continued even during the cooling cycle until the temperature reached 1300° C.)
[0064] The infiltrated sample was recovered from the pot and investigated. Microstructural analysis showed that the compact was well infiltrated to a depth of at least 2.5 mm. The infiltrated volume was observed to be completely free of pores, with a high concentration of diamond. XRD analysis showed only diamond and SiC, with no residual unreacted elemental or free silicon present in the compact. The diamond content of the compact was estimated to be approximately 40 volume %, with the remainder being SiC phase.
Examples 2-7
[0065] Further diamond compacts was prepared according to the method of example 1, save that the diamond average grain size and phenolic resin content were altered as shown in Table A.
[0000]
TABLE A
Table A Summaries of various characteristics
of the compacts produced.
Diamond
Preform
Infiltration
Phase composition
grain size
resin content
depth
(volume %)
Example
(μm)
(mass %)
(mm)
Diamond
SiC
Si
1
1.5
10
2.5
40
60
0
2
9
10
full
53
47
0
3
1.5
5
1.25
—
—
—
4
9
5
2
46
51
3
5
1.5
20
poor
—
—
—
6
9
20
poor
—
—
—
7
16.5
5
full
52
40
8
[0066] As is evident from Table A, excess quantities of phenolic resin are undesirable in that they cause a similar pore-blocking effect to that observed without any resin being present. In this case, optimal levels of resin addition at approximately 10 mass % were observed to maximise the infiltration process and reduce the presence of undesirable free silicon.
Example 8
[0067] The contents of the paper ‘The low-pressure infiltration of diamond by silicon to form diamond-silicon carbide composites’ as authored by Sigalas, Herrmann and Mlungwane is incorporated herein by reference. For the avoidance of doubt, the paper is set out below:
Abstract
[0068] The infiltration of fine-grained diamond preforms by molten silicon is limited by the blocking of the pores as a result of the volume increase during the reaction of diamond with SiC. Therefore in the present paper the infiltration of preforms made with diamond powders with different grain sizes was investigated. The preforms were prepared using phenolic resin as a binder. With increasing resin content the pore size increases, but the pore volume decreases. As a result the infiltration depth increases strongly for medium resin content. For the fine-grained ˜1.5 μm diamond preforms, a maximum infiltration depth of 2.5 mm is obtained at 10% resin, whereas at 5% resin only 1.25 mm could be infiltrated.
1. Introduction
[0069] Diamond is the hardest material known to man. Because of this, it finds extensive industrial application where ultra-hard material properties are needed. Due to its high hardness, it is difficult to make diamond tools of different shapes and sizes purely from cutting and shaping diamond. This has led to the development of diamond composite materials which consist of small diamond grains either sintered together through a liquid phase sintering process, or held together in a matrix by a binder phase material. The former process gives rise to the class of polycrystalline diamond materials (PCD), while the latter results in a number of composite materials, of which the foremost is that of SiC-diamond composites. The introduction of the second phase improves the formability and the fracture toughness of such diamond-based materials 1 .
[0070] Metallic phases such as cobalt are present in PCD and are commonly used as liquid phase sintering aids in the production of that material. These metals however were found to catalyze the graphitization of diamond thus limiting the application temperatures of these PCD materials to below 1000° C. 1 . Silicon carbide has been found to be exceptionally good as a diamond binder phase. Because of the structural similarities between diamond and silicon carbide, a strong bond forms between them 2 resulting in a material with a very strong adhesion between the diamond grains and the SiC matrix. Silicon carbide does not react with diamond and the composite material can be used at temperatures above 1000° C. Application temperature is limited by the melting temperature of silicon if some unreacted silicon is present in the final product.
[0071] SiC is commonly formed in situ from a reaction between diamond and/or amorphous carbon or graphite with silicon. The silicon can be introduced into the diamond in different ways, either by infiltrating molten silicon into a diamond preform or by reaction sintering silicon powder and diamond powder 3, 4, 5.
[0072] The main production route of these composites includes the use of high-pressure and high-temperature in order to achieve sintering within the regions of diamond stability [6]. Use of high pressures however restricts the range of applications of these materials due to high cost of production and the limited range of possible sizes and shapes of the products made. Some attempts 5 have been made to produce this composite material under conditions of low pressure (i.e. in the diamond metastable region). Hot Isostatic Pressing (HIP) method was employed at a maximum pressure applied of 20 MPa. A product more than 90% dense was obtained. It is of great importance to note that for the reaction sintering route, if the reaction proceeds under low pressure conditions, voids are produced within the body because of the volume reduction occurring during the reaction 7 .
[0073] The advantage of infiltration as stated by J. Qian at al 2 , is that the liquid phase keeps filling the pores in the diamond skeleton and hence a more dense material is produced. Infiltration can also be successfully performed at low pressures giving a dense product.
[0074] Infiltration on the other hand has been successful under low pressure conditions only for large grained diamond preforms (7-63 μm grain size) 3, 4 . It should be noted that in these materials a wide grain size distribution was used. Even under high pressure (7.7 GPa, 1400-2000° C.), E. A. Ekimov et al. 8 could infiltrate diamond powder with primary grain size of ˜10 nm but secondary particle (agglomerate) size of ˜1 μm only up to an infiltration depth of 2 mm.
[0075] Therefore the aim of this study is to investigate the infiltration of diamond by silicon using minimal pressure, and to analyze the limitations accompanying the infiltration of small diamond grain size preforms.
2. Experimental
2.1. Preform Preparation
[0076] Preforms were produced using three different diamond powders, labelled D2, D9 and D17 (Element Six (Pty) Ltd). The characteristics of these powders are given in Table 1. The composition of the diamond preforms was modified by the addition of phenolic resin (Plyophen 602N; Fa. PRP Resin). This component was necessary for the formation of the preform during pressing. It acts as a lubricant and a binder. Resin concentrations of 5, 10 and 20 wt % were investigated. The composition and names of the samples are given in Table 2. For the preparation of the preforms phenolic resin was dissolved in acetone (34.3 g/l) and mixed with the diamond powder. This suspension was stirred continuously while kept in a water bath at 70-80° C. to evaporate off the acetone. The resulting powder is agglomerated, the degree of agglomeration increasing with increasing resin content and decreasing diamond particle size. The agglomerated powder is crushed and screened using a −325 mesh screen. The screened powder is pressed into a green compact of 18 mm diameter and 5 mm height under 60 MPa of pressure for about 5 seconds.
[0077] The green compacts were heat treated at 120° C. for 18 hours to cure the resin in air. They were then weighed and the resin pyrolysed under argon by heating at a rate of 2° C./min up to 450° C. followed by 10° C./min up to 750° C. where a dwelling time of 60 minutes was undergone. Cooling to room temperature was carried out at a rate of 10° C./min.
[0078] The preforms' green density and porosity were determined after pyrolysis. The green densities were calculated from the mass and volumes of the preforms while the porosity and the pore size distributions were determined using a mercury porosimeter (Quantachrome Poremaster-60). Raman spectra were acquired with a Jobin-Yvon T64000 Raman spectrometer operating in a single spectrograph mode with an 1800 lines/mm grating. These measurements were performed in order to determine the uniformity of the resin coating. For each sample a line 1000 micron in length and consisting of 100 points was mapped in the central region of the sample using a motorized XY stage.
2.2. Infiltration
[0079] An excess amount of silicon powder (1-20 μm Goodfellow) was cold pressed into an 18 mm diameter tablet. This tablet is then placed in an hBN-coated graphite pot ( FIG. 1 ). The diamond preform is placed on top of this Si tablet. Three SiC pieces of 2×2×3 mm size are used to separate these two tablets so that no reaction in the solid state, during heating up, can take place. An hBN-coated graphite piston covers the pot. The set-up was heated up at 50° C./min to 1500° C. at which temperature it dwelled for 30 minutes. Cooling was achieved at a rate of 20° C./min. Pressure (20 MPa) is applied onto the piston after the temperature exceeds that at which silicon melts (±1420° C.) to bring the preform and the melt into contact so that infiltration can commence. It is then released when the temperature reaches 1300° C. during cooling.
[0080] The products of the infiltration were cross-sectioned. The cross sections were polished using resin bonded diamond wheels with 1 μm diamond at 3000 rpm before characterization with SEM and XRD.
[0081] The phase composition of the infiltrated materials was determined by quantitative image analysis using image Tool3.
3. Results
3.1 Preforms
[0082] SEM micrographs of two of the diamond powders used and the powders mixed with the resin are shown in FIG. 2 . It can be inferred that the resin coated the diamond homogeneously both before and after pyrolysis. This was confirmed also by the Raman spectroscopy measurements. FIG. 3 indicates that both the materials produced from D2 and D9 which initially had 20% resin have thicker graphitic carbon layers than their 5% counterparts. The main graphitic carbon G-band gave fairly constant peak intensity in all samples for all the mapped points, indicating fairly uniform coverage by the resin.
[0083] The pore size distribution determined by Hg-porosimetry is given in FIG. 4 for the preforms prepared from diamond powder D2 and D9. In Table 2 the green densities and mean pore channel diameter are given. An increase in the resin content increases the average pore diameter while decreasing the pore volume. The decrease of the pore volume is more pronounced for the smaller diamond grain sizes. Nevertheless the overall green density is nearly constant.
[0000] 3.2 Infiltration Results The results of the infiltration experiments for the different preforms are given in table 2. The micrographs in FIG. 5 show the cross sections of infiltrated samples. The infiltration depth for the different materials is clearly visible. Increasing the amount of the resin in the preforms up to 10 wt % improves the infiltration of the green compacts for the materials produced from the low grain sizes diamonds, e.g. for the material D2Pr05 with 5% resin the infiltration depth was only 1250 μm and increases up to 2500 μm for the material with 10 wt % resin (D2Pr10).
[0084] The SEM micrographs of the polished sections ( FIG. 6 ) clearly indicate that the infiltrated areas are completely free of pores and with a high concentration of diamond. This could be confirmed by XRD. While in the coarse grained product the presence of free silicon is obvious (the white phase), this is not detectable for the materials with the medium and fine diamond powders, where one can only see the black diamond phase and the grey SIC phase. The amount of diamond determined by image analysis could be slightly overestimated.
4. Discussion
[0085] As was shown previously 9 diamond is well wetted by liquid silicon at temperatures higher than 1450° C. Therefore a pressureless infiltration would be possible.
[0086] The infiltration is hindered by the formation of SiC surface layers on the diamond, which can block the pore channels and reduce the infiltration depth. Additionally the silicon will react with the added phenolic resign. The investigations of the reaction of liquid silicon with CVD-diamonds, glassy carbon and graphite has shown 9-11 , that the reaction in all cases results in a very fast formation of protective SiC-layers with similar thickness. The reaction is faster for less crystalline carbon sources. In the infiltrated samples no residual non diamond carbon was observed. This indicates that the resin converts preferentially into SiC.
[0087] The fast reaction of the carbon with liquid silicon results in blocking of the pore channels and is also the reason why infiltration experiments so far were successful only with preforms made of diamonds having large pore sizes 3-4 . The reaction of silicon with diamond or other carbon sources is further enhanced by the strong exothermic character of the interaction of silicon with carbon. This results in a pronounced heat up of the system 10 and an acceleration of the reaction resulting in premature blocking of the pores.
[0088] The pyrolysed resin in the sample strongly changes the microstructure of preforms. It increases the pore channel diameter, e.g. by a factor of 1.5 times for D2Pr samples and by a factor of 3 for the samples with the medium grain size (D9).
[0089] Unfortunately at the constant pressure used for the preparation of the preforms the pore volume decreases with increasing resin content, i.e. pores between the diamond particles are filled by the pyrolysed resin. The reduction of the pore volume is more pronounced for the low grain size diamond composites (nearly 70%) whereas the change for the samples made with D9 powder it is only 38%. This reduction can be reduced by decreasing the pressure during compaction of the preform.
[0090] Small amounts of resin (5 wt %) are needed to make the pressing of the diamond powder possible. Without the presence of resin no pressed samples could be prepared. The resin coats the diamond particles ( FIG. 2 ). This coating plastically deforms during pressing and glues the diamond particles together. With increasing resin content the resin will begin to fill the pores of the preform, during the pressing process, starting with the smaller ones. Therefore only the larger pores will remain and the overall porosity will be reduced. If the diamond particles had a constant packing density in the green body and the resin fills only the pores then the green density had to be increased with increasing resin content. In the investigated samples the density reduces slightly with the increasing resin content. This indicates that the distance between the diamond particles increases with increasing resin content.
[0091] To some extend the pore structure in the high resin content materials can be related also to the structure of the granulates prior to the pressing of the preform. However no inhomogeneity of the diamond, Si and SiC distribution was found after infiltration ( FIG. 6 ).
[0092] This changed pore structure with increasing resin content will influence infiltration in the following ways:
The increase of the pore channel radius will improve the infiltration. Therefore for preforms with up to 10 wt % resin content a strong increase in the infiltration depth was observed. The reduction of the overall porosity by deposition of the resin between the diamond particles will reduce the infiltration depth due to the possibility of blocking the pores. The volume increase during the reaction of diamond with liquid silicon is much larger than for the amorphous carbon or graphite with silicon. Therefore the reaction of the resin with liquid silicon will result in the blocking of the pores to a lesser extend. This will reduce the influence of the reduction in porosity. It was shown, that carbon preforms with overall densities less than 0.9 g/cm 3 can be fully converted into SiC 12 . Therefore the resin themselves with a density of less than 1 g/cm 3 can be converted completely. Therefore the medium resin content improves the infiltration and only high resin content decrease the infiltration due to the lower porosity. Therefore the reduction of the porosity has only a decisive influence on the infiltration at higher resin content (20%).
[0095] The study of the interaction of diamond with molten silicon has shown that after the onset of the interaction, a SiC layer of 5-10 μm thickness is formed very quickly on the surface of the diamond particles. The thickness of the layer is controlled by the density of the nuclei formed. If the amount of nuclei is large the thickness of the layer directly formed would be lower [9] and infiltration would be possible to a higher infiltration depth. A similar effect could be caused by the faster reaction of the pyrolysed resin, which would help improve the infiltration additionally. For the material D22Pr5 after 30 min infiltration the thickness of the SiC-layers formed on the diamonds can be estimated to be in the range of 2-5 μm. ( FIG. 6 a ). This value is less than what was observed in model experiment with CVD-diamond plates 9 .
[0096] The resin has the additional effect that a smaller amount of diamond is converted to SiC. Therefore high amounts of diamond were observed in our samples after infiltration.
[0097] The large grained products contain some free silicon due to their large pores in the preforms. The Si, which remains after formation of the dense SiC layer around the diamond, reacts only very slowly because this reaction is controlled by the diffusion through the SiC-layer 9, 11 . The medium and fine grained products have no detectable free silicon in them which is in agreement with this explanation.
5. Conclusion
[0098] The investigation of the infiltration of diamond preforms produced from mixtures of phenolic resin and diamond of different grain sizes from 1.5-17 μm can be summarized as follows:
1) The addition of the resin allows a simple shaping of preforms. 2) Increasing the amount of resin causes pronounced increases of the pore channel diameter and reduces the amount of porosity at similar green densities, because the resin fills partially the space in between the skeleton formed by the diamond particles. 3) Despite the fact that the overall porosity is reduced by adding the resin, the infiltration depth increases by a factor of two for the D2Pr10 in comparison to the D2Pr05. Similar effects were found for the samples with coarser grain size (D9Pr10). 4) For a larger resin content the infiltration depth decreases again strongly due to the much lower pore volume
REFERENCES
[0103] The following references are included herein by reference.
1 Tomlinson P. N., Pipkin N. J., Lammer A. and Burnand R. P. Indust. High performance drilling-Syndax 3 shows versatility. Diamond Rev., 6 (1985) 299. 2 Qian J., Voronin G., Zerda T. W., He D. and Zhao Y. High-pressure, high-temperature sintering of diamond-SiC composites by ball-milled diamond-Si mixtures. J. Mater. Res., 17 (8) (2002) 2153. 3 Gordeev S. K, Danchukova L. V., Ekstroem T., Zhukov S. G. Method of manufacturing a diamond-silicon carbide composite and a composite produced by this method. CA2301775, 1999. 4 Gordeev S. K., Zhukov S. G., Danchukova L. V., Ekstrom T. Method of manufacturing a diamond-silicon carbide-silicon composite and a composite produced by this method. EP1253123, 2002. 5 Shimono M. and Kume S., HIP-Sintered Composites of C (Diamond)/SiC. J. Am. Ceram. Soc., 87 (4) (2004) 752. 6 Hall H. T., A Synthetic Carbonado. Science I, 169 (39) (1970) 865. 7 Hillig W. B., Making ceramic composites by Melt Infiltration. American Ceramic Society Bulletin, 73 (4) (1994) 56. 8 Ekimov E. A., Gavriliuk A. G., Palosz B., Gierlotka S., Dluzewski P., Tatianin E, Kluev Y., Naletov A. M. and Presz A. High-pressure, high-temperature synthesis of SiC-diamond nanocrystalline ceramics, App. Phys. Lett., 77 (2000) 954. 9 Mlungwane K., Sigalas I., Herrmann M. and Rodriguez M., The wetting behaviour and reaction kinetics in diamond0silicon carbide system. Submitted for publication In Diamond and Related Materials 10 Sangsuwan P., Tewari S. N. Gatica J. E., Singh R. N., and Dickerson R. Reactive Infiltration of Silicon Melt through Microporous Amorphous Carbon Preforms, Metallurgical and Materials Transactions B, 30B (1999) 933. 11 Zhou h., Singh R N. Kinetics model for the growth of silicon carbide by the Reaction of Liquid Silicon with Carbon. Journal of the American Ceramic Society 78 (9) (1995), 2456-2462 12 Siegel S., Petasch u., Boden G., Biogene Keramik-eine Alternative?, Keramische Zeitschrift, (2004), 4 234-238
[0000]
TABLE 1
The mean particle size of the three
diamond grades used in the experiments.
Mean
particle size (μM)
Diamond grade
D (v, 0.5)
D (v, 0.9)
D2
1.51
2.46
D9
9.02
16.42
D17
16.82
22.38
[0000]
TABLE 2
A summary of the infiltration results of the preforms containing different amounts of resin.
WEIGHT
GREEN DENSITY
INFIL-
PHASE
RESIN
LOSS DURING
(AFTER
MEAN PORE
TRATION
COMPOSITION,
DIAMOND
CONTENT,
PYROLYSIS,
PYROLYSIS),
POROSITY,
DIAMETER,
HEIGHT,
VOL %
SAMPLE
POWDER
wt %
%
g/cm 3
%
μm
μm
Diamond
SiC
Si
D2PR05
D2
5
1.86 ± 0.03
1.82
40
0.47
1250
0
D2PR10
10
4.11 ± 0.01
1.80
29
0.59
2500
0
D2PR20
20
8.73 ± 0.07
1.79
11
0.77
17
36
64
0
D9PR05
D9
5
2.00 ± 0.02
1.84
38
2.7
2000
46
51
3
D9PR10
10
4.10 ± 0.02
1.78
29
4.9
5000 1)
53
47
0
D9PR20
20
9.00 ± 0.03
1.71
15
8.8
97
0
D17PR05
D17
5
2.2 ± 0.2
1.97
25
5.7
5000 1)
52
40
8
D17Pr10
10
2.17
30.2
6.8
5000 1)
1) Fully infiltrated
FIGURE CAPTIONS
[0116] FIG. 1 . The schematic set-up for the infiltration experiments.
[0117] FIG. 2 . SEM micrographs of diamond powders D2 and D9 showing the effect of coating the diamond. a) and b) is powder before coating, c) and d) fracture surfaces of the green compacts before pyrolysis, and e) and f) fracture surfaces of the preforms before infiltration.
[0118] FIG. 3 . The average ratio of G-band intensity to diamond Raman peak intensity for the D2 and D9 diamond with initial 5 and 20% resin after their pyrolysis.
[0119] FIG. 4A . The pore size distribution in D2 diamond preforms containing 5%, 10% and 20% resin.
[0120] FIG. 4B . The pore size distribution in D9 diamond preforms containing 5%, 10% and 20% resin.
[0121] FIG. 5 . SEM micrographs showing the infiltration depths of a) D2 (i) 5% resin, (ii) 10% resin and (iii) 20% resin, and b) D9 (5% resin), after infiltration at 1500° C. for 30 minutes
[0122] FIG. 6 . Typical backscattered SEM micrographs of polished cross sections of a) D17 (5% resin), b) D9 (10% resin) c) D2 (10% resin), after infiltration at 1500° C. for 30 minutes. d) The same as c) but with higher magnification. The black phase is diamond, the white (where present) is free silicon and the grey phase is SiC. | The invention relates to an abrasive compact comprising a mass of diamond particles and a silicon containing binder phase wherein the diamond particles are present in an amount less than 75 volume % and the binder phase contains less than 2 volume % unreacted (elemental) silicon. The invention further relates to a method of producing an abrasive compact including the steps of forming a feed diamond powder into a diamond preform, interposing a separating mechanism between the diamond preform and a silicon infiltrant source, heating the diamond preform and silicon infiltrant source until the infiltrant is molten and the preform and infiltrant are isothermal and allowing infiltration from the molten silicon infiltrant source to occur into the diamond preform. | 2 |
REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 69,367, filed July 2, 1987, now abandoned.
BACKGROUND AND SUMMARY OF INVENTION
The present invention relates to trouble lights and, more particularly, to an improved trouble light and shield therefor in which the risk of being burned through contact therewith is minimized.
Trouble lights are a common device used by service personnel and many automobile owners to illuminate an area, such as, for example, under an automobile, where inadequate lighting conditions hinder the ability to work in such an area. In the past, trouble lights typically consisted of a switch and socket assembly, a light bulb secured within the socket, and a housing combining a sheet metal reflector and a wire guard. These lights utilize the reflector positioned on one side of the bulb to reflect the light towards the work area. The wire guard portion of the housing was used to prevent inadvertent contact with the bulb which would cause burns and possibly break the bulb. Also, the reflector in these lights typically abutted the wire guard and provided one or more points of contact between the two and transferred heat to the wire guard. A problem associated with this type of light stems from the fact that the light bulbs utilized therein must provide sufficient illumination on the work area. The bulbs which fulfill this need develop a considerable amount of heat. Since the bulb is positioned in close proximity to the reflector portion of the housing, the temperature of the reflector portion can rise due to radiation and contact between the reflector and wire guards and produce a painful burn, even after only a short period of use. In addition, trouble lights are often used in applications where the work space is cramped. Therefore, it is desirable to construct the housing assembly as small as possible so that the light can be inserted where desired. Decreasing the size of the housing, however, moves the reflector portion closer to the light bulb and also moves the reflector into contact with the guard and thus increases the temperature of the reflector.
Various types of trouble lights have been designed in an effort to prevent burns caused by the reflector. One is disclosed in U.S. Pat. No. 3,108,752 in which a trouble light having a housing made from a wire guard and a sheet metal shield is disclosed. A reflector having ventilating slots therein is concentrically mounted to the shield between the shield and the bulb by a pair of rivets. While such a construction initially insulates the shield, after prolonged use, both the reflector and the shield attain high temperatures due to the minimal circulation of air between the reflector and the shield.
U.S. Pat. No. 4,328,535 describes a trouble light having a thermal insulating cloth pad which is positioned on the exterior surface of the reflector. This insulating pad may become snagged in a congested work area and become separated from the reflector and thus require the user to occasionally reposition it. In addition, because the pad is made from cloth, it will likely absorb moisture and/or grease and/or oil whereby it will readily conduct heat through the pad, or even worse, become a fire hazard.
Fluorescent bulbs have also been proposed to replace the typical incandescent bulb because of their lower operating temperatures. However, fluorescent bulbs are substantially more expensive than a comparable incandescent bulb thus making the fluorescent-type trouble lights cost prohibitive for many purchasers.
The trouble light of the present invention overcomes the aforementioned shortcomings by utilizing a wire guard assembly which completely encircles the bulb and reflector. The reflector is positioned substantially adjacent the bulb. An air gap is provided between the reflector and the wire guard and contact between the reflector and guard assembly is prevented to effectively prevent substantial heat transfer between the reflector and the wire guard. Any minimal heat transfer which may occur is further minimized by coating the wire guard with a thermal and electrical insulator. The wire guard has a plurality of wires which are radically spaced apart and prevent inadvertent contact by the user with the reflector. The air gap between the wires and reflector permits air to freely pass over the reflector and prevent heat transfer to the guard such that the guard maintains a relatively cool temperature which a user may contact without being burned.
Accordingly, it is a general object of the present invention to provide an improved trouble light.
Another object of the present invention is to provide a trouble light having a predetermined distance and an air gap between the reflector and the guard assembly to eliminate heat transfer to the guard assembly.
Another object of the present invention is to provide a trouble light in which the wire guard assembly surrounding the light bulb is coated with a thermal insulator.
A further object of the present invention is to provide a trouble light in which the wire guard surrounding the light bulb is coated with a thermal and electrical insulator.
A still further object of the present invention is to provide a trouble light in which the light bulb enclosed within the housing is readily accessible.
Yet another object of the present invention into provide a trouble light shield with positioning means to maintain the light reflector a predetermined distance from the guard assembly and to prevent relative movement and contact between the two.
These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the course of this description, reference will be made to the attached drawings in which:
FIG. 1 is a perspective view showing a first embodiment of a trouble light shield constructed in accordance with the principles of the present invention mounted on a trouble light base;
FIG. 2 is a front elevation view of the trouble light shield shown in FIG. 1
FIG. 2A is an enlarged view of a portion of FIG. 2 with the front access portion of the guard assembly removed;
FIG. 3 is a rear elevation view of the trouble light shield shown in FIG. 1;
FIG. 4 is a side elevation view, partly in section, of the trouble light shown in FIG. 1; and
FIG. 5 is a sectional view taken along line 5--5 of FIG. 4 with the light bulb removed for clarity.
FIG. 6 is an enlarged sectional view illustrating a second embodiment of a trouble light shield constructed in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a first embodiment of a trouble light shield 10 incorporating the principles of the present invention. The trouble light shield 10 is shown attached to a conventional handle member 11 which has a light bulb 12 mounted therein. Reflector means in the form of a reflector shield 13 are positioned adjacent the bulb and guard assembly means, indicated generally 14, surround the bulb 12 and reflector means 13.
The handle member 11 is of known construction and includes a conventional socket 15 which receives a light bulb 12. A push-button switch 16 may be provided to operate the light. An outlet 17 may also be provided on handle 11 to provide a convenient location for powering electric hand tools when using the trouble light. An insulated conductor 20 is fed into the handle member 11 through a bore (not shown) in the bottom thereof.
Reflector shield 13 is elongate and preferably formed of metal or a suitable temperature resistant material and as seen in FIG. 2A is generally semi-circular in cross-section. It extends beyond the full length of bulb 12 so that it reflects light from the bulb 12 toward the work area. As best shown in FIG. 5, reflector 13 is dimensioned and mounted adjacent socket 15 by way of a first positioning means which includes a first collar 23 such that it is positioned a predetermined distance away from the outer diameter 22 of the bulb 12. First collar 23 fits into a circumferential groove or channel 24 on the handle 11 and is held in place within the channel 24 also by way of the guard assembly portion of the first positioning means which also includes a second collar 25. In order to properly align the reflector 13 within the guard assembly 14, first and second collars may be provided with alignment means in the format of detents 7,8 which engage each other. As best seen in FIGS. 3 & 5 a first detent 7 is disposed on the reflector first collar 23 and a second detent 8 of a shape similar to that of the first detent disposed on the guard assembly second collar 25.
The guard assembly means 14 comprises a fixed guard portion 26 and a pivoting bulb guard access portion 27. Guard portion 26 is formed from a plurality of radially and equally spaced vertical wires 28 which are secured to collar 25 by welding or the like. At their tops 31, the wires are secured to heat transfer means comprising a generally semi-circular flat plate member 32 in a similar manner to provide a rigid guard structure enclosing bulb 12. The wires 28 are preferably constructed of metal, and may be coated with a thermal and/or electrical insulation 39. Through the use of a thermal insulating coating, any temperature increases in the wire guard assembly 14 are further minimized.
The guard access portion 27 of guard assembly means 14 is constructed from the same material as the fixed guard portion 26. As best shown in FIGS. 1-4, the guard access portion 27 is constructed from a wire bent into a generally rectangular-shaped member 33 which forms the horizontal portions of the bulb guard access portion 27. The vertical portions of the guard access portion are preferably formed from a wire bent into a generally U-shaped member 34 in which the legs 35 thereof are substantially vertical. This U-shaped member can also be secured to the rectangular-shaped member 33 by welding or other similar method. An additional vertical member 36 is secured to both the rectangular-shaped member 33 and the U-shaped member 34 and has hanging means thereon which includes hook 37 formed at the top end thereof for hanging the trouble light 10.
One side of the rectangular-shaped member 33 has a pair of opposed vertically depending members 40 which fit into a pair of mating tubes 41 mounted on the end vertical wire of the guard fixed portion 26 in order to create a hinge assembly 45. The opposite side of rectangular-shaped portion 33 of bulb guard 27 has a tab 46 extending therefrom which engages the other side of reflector guard 26 to form a latch assembly indicated generally at 47.
The reflector shield 13 and guard assembly means 14 are secured in position around bulb 12 and the top of handle member 11 by the first positioning means first and second collars 23,25 which are held in channel 24. The first collar 23 sits within the second collar 25 and is held therein when tightening means, such as nut and bolt assembly 50, is applied. The first and second collars 23,25 establish an initial predetermined distance between the reflector 13 and the fixed guard portion 26 as well as establish a spacing between the light bulb 12 and the reflector 13.
In an important aspect of the present invention, this first positioning means establishes a predetermined distance which includes an air gap 29 between the reflector 13 and the guard assembly means 14 (FIGS. 4 or 5) therebetween (FIGS. 4-5). This air gap 29 extends about the rear perimeter of the reflector shield 13 and is disposed between the reflector 13 and the radial wires 28 of the guard fixed portion 26. With its air gap 29, this predetermined distance allows air to flow over the rear of reflector shield 13 and so prevents heat transfer between the reflector shield 13 and guard assembly means 14.
In yet another important aspect of the present invention, second positioning means 60 in the form of two posts 62 is provided at the top of the fixed guard portion 26 and maintains the predetermined distance and air gap 29 between the reflector shield 13 and the fixed guard portion 26. Importantly, these posts 62 provide a point of engagement between the reflector shield 13 and fixed guard portion 26 to prevent any relative movement of the reflector shield 13 with respect to the radial wires 28 in case the first and second collars 23,25 loosen. As such, second positioning means prevent the reflector shield 13 from substantially contacting the fixed guard portion 26, thereby eliminating any heat transfer via conduction between them.
As shown in FIG. 2A, two positioning posts 62 depend downwardly from heat transfer means in the form of a semicircular plate 32 and engage the reflector shield 13 by protruding through openings 64 therein. These posts 62 fix the reflector shield 13 in place with respect to the fixed guard portion 26 so that the reflector shield 13 is maintained in its predetermined distance away from the radial wires 28 of the fixed guard portion 26. Contact between the reflector means 13 and the radial wires 28 is thereby prevented and heat cannot be transferred to it through contact alone. The only heat which can be transferred to the guard assembly means 14 is minimal and occurs via of posts 62 to the heat transfer plate 32. The relatively large surface area of plate 32 seems to rapidly disapate heat to the atmosphere.
FIG. 6 shows another embodiment of a trouble light shield incorporating the principles of the present invention. In this embodiment, the second positioning means 70 includes an outward rim 72 disposed about the periphery of the reflector shield 74. This rim 72 extends outwardly and is held between two adjacent radial wires 76,77 of the fixed guard portion 78. The contact between the reflector shield 74 and the fixed guard portion 78 is limited in this embodiment to the contact points between wires 76,77 and the rim 72. Any heat build up in the reflector 74 is transferred to the heat transfer plate 80 and quickly disapated into the atmosphere.
Preferably, the radial wires 28 are positioned close enough together to prevent the insertion of a user's finger between the wires and into contact with the reflector shield. A distance of approximately 1/2 inch has been generally found to be satisfactory. The small air gap 29 between the reflector shield 13 and fixed guard assembly 26 allows the two components to be positioned relatively close together in order to provide a trouble light which helps prevent burns yet is no larger than current models. In the event that electrical insulation 39 is used to cover or coat the wires and second collar 24 of guard assembly means 14, the guard assembly means 26 will be electrically insulated from the reflector 13 which reduces the chances of receiving an electrical shock from the reflector 13 through the wire guard 14 in the event of a short circuit.
In addition to utilizing wire or coated wire for constructing the guard assembly means 14, it may be constructed of a plastic material having sufficient strength and moldability characteristics.
It will be understood that the embodiments of the present invention which have been described herein are merely illustrative of an application of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. | A trouble light shield is disclosed for use with an elongated handle member receiving an electric light bulb thereon. The shield includes a reflector partially surrounding the light bulb and a guard assembly having a plurality of radially spaced vertical wires. Collars located at the base of the reflector and guard assembly space the reflector a predetermined distance away from the light bulb and guard assembly, while posts which extend from the guard assembly engage the reflector to maintain its predetermined distance and also to prevent any substantial contact between the reflector and guard assembly. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a division of U.S. patent application Ser. No. 14/089,170, filed Nov. 25, 2013, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present disclosure relates generally to fermentation devices and methods for the making of wine, and more particularly to a disposable wine fermentation vessel with cap management and integral press.
Statement of the Prior Art
Modern winemaking typically comprises combining winemaking ingredients in a clean, essentially sterile fermentation vessel with minimal introduction of air. For the production of red wine, these ingredients include grape skins which must be separated after fermentation. This separation operation is traditionally performed in a press.
In the fermentation of red wine, the grape skins present in the fermentation tend to float up to the top of the liquid in the fermentation vessel and form what is termed a “cap.” This cap needs to be periodically broken up so that the skins may be mixed into the liquid in order to extract color and flavor compounds from the skins and seeds. The cap must also be kept moistened to prevent the growth of deleterious aerobic bacteria. Traditionally, the agitation of the cap has been done by poking the cap with a pole to break it up. This is termed “punch down” and even automated punch down devices are available. These are usually mechanically complex and require a moving seal to prevent contamination of the fermenting wine. More modern methods include pumping the liquid in the fermenter over the cap to break it up.
Other techniques include using horizontally rotating fermentation vessels such as those described in U.S. Pat. No. 4,474,890 (Rieger) and published European patent application EP0337060 (Speidel) that force the cap into the liquid. These are expensive and complex machines with large rotating assemblies, making them impractical for most wineries. U.S. Pat. No. 6,703,055 (Klein et al.) also describe a fermentation vessel with rotating mechanical agitators to flood the cap when needed. Cap management is a major factor in red wine production, since it has a tremendous impact on the wine's color and flavor, and thereby determines the value of the resulting red wine.
At the conclusion of the fermentation, the contents (i.e., fermented juice, spent skins, and yeast) are typically pumped to a press where the fermented juice is separated from the skins, seeds, and dead yeast. This is a complex and labor-intensive operation, and requires the press to by emptied and cleaned multiple times. Presses are very prone to clogging and must be emptied and cleaned manually to continue the pressing operation. Multiple transfers between the equipment also increases the risk of contamination. This problem is well recognized and there have been some attempts in the prior art (e.g., U.S. Pat. No. 7,552,675 (Lorinez) and U.S. Pat. No. 7,891,291 (Lorinez)) to develop fermentation vessels that have integral pressing capabilities. These attempts too are very complex and expensive machines with hydraulic rams under computer control. Solids, which are called “pomace” and consist of skins, stems, seeds and dead yeast, are left behind in the fermentation vessel and requires personnel to enter the vessel and shovel it out.
In certain winemaking operations, the contents of the fermentation vessel are allowed to settle and then the clarified fermented juice is removed, leaving the spent “lees” (i.e., the deposits of dead yeast or residual yeast and other particles that precipitate, or are carried by the action of “fining,” to the bottom of a vat of wine alter fermentation and aging) behind. This is traditionally done by siphon which takes considerable time. Transfer can be speeded up by pressurizing the fermentation vessel, but this requires the fermentation vessel to be pressure rated—considerably increasing the cost. U.S. Pat. No. 8,015,915 (Puissant) describes a fermentation vessel with internal lees containment, but this comprises a very complex conical vessel and expensive mechanical apparatus. It can be seen, therefore, that a need exists in the winemaking process to rapidly transfer liquids from one container to another without contamination.
Another major issue, especially for smaller wineries, is the disposal of waste wash water. Traditionally, winemaking equipment is made of stainless steel and this equipment must be cleaned before and after each use. The wash water contains a high biological load due to the spent grape skins and yeast. The water may also contain large amounts of harsh detergents and disinfecting chemicals. This waste water can amount to as much as 10 times the fermentation vessel volume and must be treated before discharge to streams or municipal treatment facilities. The capital and operating cost of this waste treatment can be prohibitive to a small winery. Furthermore, many communities restrict the water usage and also the discharge of waste water in order to protect the environment. Embodiments of the present invention overcome this problem by providing a pre-cleaned fermentation vessel comprising a single-use plastic bag. At the end of the fermentation, the fermented juice is pressed and most of the solids (i.e., pomace) are retained in the plastic bag which can then be disposed of as solid municipal waste or landfill. This eliminates almost all the washing requirements and manual cleaning operations.
Thus, there are four important problems to be solved in the wine fermentation process, particularly with red wines: i) a means to provide a clean, preferably sterile, anaerobic environment for the fermentation to prevent contamination; ii) a means to agitate the cap to extract flavor and color from the skins; iii) a means to press out the fermented juice without the need to transfer to another vessel; and finally iv) a means to perform all these functions with a pre-cleaned single-use disposable fermentation vessel that generates minimal waste wash water and eliminates labor-intensive cleaning. As will be evident from the description, embodiments of the present invention overcome all these problems.
SUMMARY OF THE INVENTION
Accordingly, it is one object of embodiments of the present invention to provide a fermentation vessel for the production of wine, particularly red wine, that is supplied clean and ready to use. An integral bladder may be provided to facilitate agitation of the cap and to press out the spent grape skins and yeast. The entire fermentation vessel containing most of the waste solid material may then be discarded, thus obviating any need for decontamination or cleaning. Expected advantages may include better cap management, minimal waste water generation, and a drastic reduction in labor costs. The device may also be used for secondary fermentations and for the separation of settled solids (called “racking”).
The device may comprise a plastic bag with a form-fitting shape that may be contained inside a rigid outer container. The plastic bag suitably comprises a closed container with two isolated chambers. The must (i.e., grape juice, crushed grapes, skins, seeds, and stems) only contacts the inside surface of a primary or fermentation chamber of the plastic bag. These materials may be loaded into the fermentation chamber of the bag at the start of the fermentation process. The bag also comprises a secondary or pressurization chamber which may be isolated from the fermentation chamber and pressurized by an external compressed air supply. The function of this pressurization chamber will be described in greater detail herein below. But, at the start of the fermentation process, the pressurization chamber will be completely deflated.
At this starting stage, the empty bag may be partially filled with the must to be fermented leaving minimal air in the headspace. This effectively eliminates air in the fermentation, allowing for mildly anaerobic conditions that favor proliferation of the yeast, and suppresses growth of contaminating aerobic bacteria. The use of an empty bag eliminates the traditional need to purge the headspace of the fermenting tank with nitrogen or other inert gases. A spring-loaded pressure relief valve on the bag vent ensures that air from the environment does not enter the fermentation chamber. As the yeast fermentation progresses, carbon dioxide (CO 2 ) is produced and this CO 2 fills the headspace of the fermentation chamber so that it becomes inflated. Excess CO 2 may be automatically vented through the relief value to keep the headspace pressure constant. This ensures the necessary anaerobic environment. The positive pressure inside the fermentation chamber prevents contaminants from entering.
As the fermentation progresses, a cap of grape skins, seeds, and stems rises and floats on top of the fermenting liquid. This is due to the constant rising stream of CO 2 bubbles. It may be necessary to periodically break up and mix this cap into the bulk liquid. This may be readily achieved by inflating the secondary chamber with compressed air, thus causing the secondary chamber to expand. The fermentation chamber may be simultaneously depressurized so that when the secondary chamber expands it threes the material in the fermentation chamber to be pushed up. This squeezes the cap and forces liquid up through the cap. After a few minutes, the secondary chamber may be deflated and the fermentation chamber settles back to a horizontal configuration. The cap is now dispersed and wet. The fermentation chamber is then forced to vent through the pressure relief valve. As the fermentation continues, more CO 2 is produced and the fermentation chamber will inflate again. It is important that the fermentation chamber be depressurized during the mixing operation. If it is not depressurized, then the gas in the fermentation chamber will resist the expansion of the secondary chamber and there will be minimal movement of the cap. This cap mixing cycle may be repeated periodically during the fermentation, depending on the amount of cap management desired and based on the degree of color and flavor extraction desired. A simple electric blower may be used to inflate the secondary chamber. Since the secondary chamber is isolated from the fermentation chamber, no air is introduced into the fermentation.
Embodiments of the present invention take advantage of the fact that the thick mass of the cap flocculates to the upper part of the fermentation vessel. As noted above, traditional cap management methods try to push the cap down into the liquid by punch down. The cap, being buoyant, resists being pushed down and is therefore minimally dispersed by the punch down. Other techniques use a pump to circulate liquid from the bottom of the fermentation vessel to spray over the cap. This “pump-around” method only wets the cap—the trickling down through the cap is not sufficient to break up the cap. According to embodiments of the present invention, the novel and unanticipated approach is to use a “squeeze-up” method—where the entire fermenter contents are squeezed from the bottom and side, forcing liquid up through the cap which, in turn, is forced up through a cross-sectional area that is about 50% smaller than the original cross-sectional area. This upward force and reduction in cross-section shears the cap and breaks it up. Liquid from below is forced through and wets it completely. Such a gentle squeeze also extracts color and flavor faster from all parts of the cap. When the pressure is removed, the dispersed cap collapses and covers the entire cross-sectional area of the fermenter. This remarkably efficient operation may only be performed using a two chamber flexible fermentation vessel as disclosed in the embodiments of the present invention.
At the conclusion of the fermentation, cap agitation is stopped for several hours. During this time, most of the solid material in the fermentation chamber floats up to form a thick dense cap. A strainer may be connected to an outlet located on the bottom of the fermentation chamber. The headspace of the fermentation chamber may then be depressurized. The outlet to the strainer may then be opened. At this point, the secondary chamber may then be inflated. This forces the contents of the fermentation chamber out through the outlet and into the strainer. The strainer may be suitably sized to remove particulate matter, while the clear fermented juice from the strainer outlet may be collected for further processing. A duplex strainer may be used to avoid any interruption in the pressing process. The secondary chamber pressure may be regulated to provide the desired degree of pressing. Fine wines are typically pressed gently to minimize astringent components, while lower grade wines require more aggressive pressing to get a greater wine yield. Once the pressing is complete, the outlet may be closed and the strainer disconnected.
The design of the dual chamber bag is such that the fermented wine near the bottom is pumped out first and the floating cap containing bulk of the solids is pumped out last. This technique puts minimal cap solids or pomace in the strainer, but instead most of it is retained in the fermentation chamber of the original fermentation bag. The bag containing the pomace may simply be removed from the rigid containment container and disposed of in a landfill. No manual operations are needed to scrape and clean the fermentation vessel. No washing is needed, and no waste water is generated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of the wine fermentation vessel illustrating the filled primary or fermentation chamber of the fermentation vessel with the secondary pressurization chamber deflated;
FIG. 2 is a side sectional view of the wine fermentation vessel illustrating the filled primary or fermentation chamber of the fermentation vessel with the secondary pressurization chamber inflated;
FIG. 3 is a side sectional view of the wine fermentation vessel illustrating the deflated, yet filled primary or fermentation chamber just after the secondary or pressurization chamber has been deflated;
FIG. 4 is a side sectional view of the wine fermentation vessel showing how the empty primary or fermentation chamber is filled with minimal air contact;
FIG. 5 is a side sectional view of the wine fermentation vessel illustrating the start of the pressing operation;
FIG. 6 is a side sectional view of the wine fermentation vessel illustrating the end of the pressing operation; and
FIG. 7 is a side sectional view of the wine fermentation vessel illustrating how embodiments of the present invention may be used for racking.
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments are discussed in detail below. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. In describing and illustrating the exemplary embodiments, specific terminology is employed for the sake of clarity. However, the embodiments are not intended to be limited to the specific terminology so selected. Persons of ordinary skill in the relevant art will recognize that other components and configurations may be used without departing from the true spirit and scope of the embodiments. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. The examples and embodiments described herein are non-limiting examples.
Referring now to the drawings, wherein like reference numerals and characters represent like or corresponding parts and steps throughout each of the views, there is shown in FIG. 1 a side sectional view of a wine fermentation vessel illustrating a filled primary or fermentation chamber of the fermentation vessel with a secondary or pressurization chamber deflated. In this particular embodiment, a dual chamber plastic bag may be used, such as an Air-Assist® IBC Liner, manufactured by CDF Corporation of 77 Industrial Park Road, Plymouth, Mass. 02360 USA.
These bags are manufactured for the pneumatically-assisted dispensing of high viscous materials such as syrup. In this illustrative embodiment, the bag has an overall volume of 1000 liters though these bags can be obtained in various sizes from 10 to 1000 liters. Headspace needs to be provided for evolved gases and also for movement of the cap during pressurization. A maximum of about 60% of the total bag volume may be usable for liquid (i.e., a 1000 liter bag is capable of holding about 600 liters of must). There is no limitation on the minimum volume that be fermented since the bag is empty to start with.
FIG. 1 shows a side sectional view of the wine fermentation vessel. In this embodiment, a rigid outer container 10 contains a dual chamber bag 20 , which is placed inside the rigid outer container 10 . The bag 20 includes a primary or fermentation chamber 21 and a secondary or pressurization chamber 22 . An outlet 40 from the fermentation chamber 21 may be routed through a hole 41 in the rigid outer container 10 . FIG. 1 shows a typical configuration during fermentation. Here, the fermentation chamber 21 is partially (e.g., up to 60%) full of the fermenting must 23 . The headspace 26 in the fermentation chamber 21 inflates to tautness due to the CO 2 gas generated by the fermenting must. An electrically-actuated, 3-way valve 44 directs headspace gases through a relief valve 30 which is capable of maintaining a constant pressure. That is, a particular pressure may be set by appropriate selection of a spring in the relief valve 30 . In this configuration, pressurization chamber 22 is deflated. During the fermentation, the cap 25 (i.e., spent skins, seeds, stems) floats on the top of the liquid 23 . The cross-sectional area 100 of the cap 25 is the entire cross section of the rigid outer container 10 .
A means to periodically agitate the must and break up the cap 25 may be found by reference to FIG. 2 . This figure shows a side sectional view of the configuration when pressurization chamber 22 is pressurized by activating a blower 48 , or by the introduction of compressed air 34 through valve 33 . Vent valve 32 is closed. The introduction of air causes pressurization chamber 22 to expand compressing the fermentation chamber 21 . Three-way valve 44 is simultaneously energized to vent the headspace 26 to atmosphere 36 . This causes excess gas in the headspace 26 to be forced out and fermentation chamber 21 distorts upwards. The expansion of the pressurization chamber 22 forces the liquid 23 in the fermentation chamber 21 upwards, squeezing the cap 25 through a reduced cross-section 101 . This shears and breaks up the cap. Liquid 23 is also forced up through the broken cap 25 up into the headspace 26 completely wetting the cap and extracting color and flavor compounds.
After a few minutes in this pressurized configuration, the pressurization chamber 22 may be depressurized by either shutting off blower 48 or by opening valve 32 and closing valve 33 . Since much of the headspace gas was forced out when the pressurization chamber was pressurized earlier, it is now no longer tautly inflated as shown in FIG. 3 . However, there will be no air introduced into the headspace 26 so the fermentation still remains anaerobic. Three-way valve 44 switches to direct any vent gases from headspace 26 through the relief valve 30 and this does not permit any air to backflow into the fermentation vessel. As the fermentation continues, the CO 2 builds up again and the fermentation chamber 21 becomes tautly inflated and the system returns to the starting configuration shown in FIG. 1 . This cap management operation may be repeated periodically (e.g., typically twice a day or as determined by the desired color extraction and flavor profile).
In wine fermentation, it is critical that air be excluded from contact with the fermenting juice. In a preferred embodiment, the dual chamber bag 20 is supplied with both chambers 21 , 22 completely empty. The empty bag 20 may be placed inside the rigid outer container 10 as shown in FIG. 4 . The crushed grapes, grape juice, seeds, stems (i.e., must) may be pumped using pump 60 through the open supply/discharge valve 42 into the outlet connection 40 to fill the fermentation chamber 21 . The fermentation chamber 21 expands with liquid as it is filled. The vent from the fermentation chamber is capped 12 . There is essentially no air in the headspace 26 during this operation. The fermentation chamber 21 can alternatively be filled through the vent port 41 leaving the outlet 40 closed. Once the fermentation chamber 21 is filled to the required volume, supply/discharge 42 is closed and the fill pump 60 disconnected. The three-way valve 44 may then be connected so as to vent headspace gases through spring relief valve 30 if the pressure in the headspace exceeds a preset limit. The must is now inoculated with yeast and the fermentation begins. As CO 2 evolves during the fermentation, it fills the previously empty headspace 26 and maintains the desired anaerobic environment in the fermentation chamber 21 .
At the conclusion of the fermentation, it is necessary to press out the fermented juice separating it from the spent grape skins, seeds, stems, and yeast debris (i.e., pomace). FIG. 5 shows how this is done in the present embodiment. The apparatus may be allowed to rest for several hours prior to harvest. This allows the bulk of the pomace in the fermentation chamber 21 to float up to form a thick dense “cap”. Then, a duplex basket strainer 50 (e.g., manufactured by Eaton Strainers, formally Hayward Strainers, of Hayward, Calif. USA) is connected to the supply/discharge valve 42 . This particular unit had a 4″ inlet and dual polymer baskets to trap solids. The unit is made of PVC and clear polyester. The duplex design allows a filled basket to be removed without interrupting the operation. A polyester strainer basket was used. These are available in mesh sizes from 1/32″ to 3/16″. The preferred embodiment utilized a 1/32″ mesh opening. Now the pressurization chamber 22 is then slowly pressurized by activating blower 44 or by opening valve 33 and closing valve 32 . Three-way valve 44 is switched to vent the headspace to outlet 36 . Now supply/discharge valve 42 is opened, introducing the fermented juice into the strainer 50 . Clarified fermented juice flows out of strainer outlet 56 to collection vessels for further processing. Pressurization is maintained in pressurization chamber 22 until all the juice is pressed out of the fermentation chamber 21 . This method of pressing is intrinsically very gentle and does not crush seeds and stems. This results in better flavor and the least extraction of unwanted astringent components. Some debris is collected in the strainer basket 58 and needs to be emptied periodically during the pressing operation, however, due to the gentle nature of the pressing in the present invention, there is no turbulence in the fermentation chamber and the bulk of the pomace 25 remains flocculated in the upper section of the fermentation. This material keeps getting compacted and pushed down as the liquid is forced out underneath. Once the flow of liquid from the fermentation chamber stops, the pressing operation is complete and supply/discharge valve 42 closed. Most of the pomace is retained in the bag as shown in FIG. 6 . The bag is now disconnected, and the dual chamber bag 20 containing the waste pomace is simply thrown away or used as fertilizer.
The present embodiment can also be used for racking. Racking involves the repeated transfer from one container to another and is part of the wine aging process. Each racking involves the settling of sediments for many days or even weeks and then removal of the clarified wine to the next processing step. The settled solids (i.e., lees) are left behind. In the present embodiment the wine in fermentation chamber is allowed to settle with the pressurization chamber deflated and the rigid outer container 10 resting on a horizontal surface. A jack 14 can be used to keep the container tilted so that the solids 27 settle away from the outlet 40 as shown in FIG. 7 . A check valve 18 can be provided on vent port 41 to prevent any ingress of air into the liquid chamber 21 . When the solids have settled sufficiently, the outlet is connected to the next processing step and the supply/discharge valve 42 opened. The pressurization chamber is then pressurized and the flow begins as described for the pressing operation. The next process steps could be a tank or another dual chamber bag for a subsequent racking operation. This gentle transfer process minimizes disturbance of the settled solids and results in a clearer wine. It enables a much faster transfer than the traditional siphon.
Another application of the present embodiment is the shipment of fresh grapes for winemaking. Currently wineries have to be located near vineyards because fresh grapes must be processed within hours of being picked to assure quality wine. It is not practical to ship refrigerated wine grapes in large quantities because they will ferment and spoil unless utmost care is taken during packaging and transportation. The alternative of shipping frozen grapes is not cost effective beyond the hobby winemaking scale. Grape juice and derived products are not suitable for the production of high quality wine. However, with the present invention, rigid container 10 containing the dual chamber bag 20 can be filled with fresh crushed grapes at the vineyard. The must can then be chilled to around 45 to 55° F. and necessary additives and yeast added. The rigid container 10 is then shipped by refrigerated truck to the winery. The refrigeration temperature will inhibit spoilage, but more importantly the yeast will start the fermentation process and suppress any competing undesired organisms. The low temperature will inhibit full active growth of the yeast so only a partial fermentation will take place during the anticipated 3-5 day shipping time. Once the rigid container 10 is received at the winery, it is heated up slowly to fermentation temperature to jump start the fermentation and the cap management techniques described earlier can be applied. At the end of fermentation the fermented juice can be pressed out as described earlier. This operation makes it practical for small wineries to use wine grapes from vineyards located hundreds of miles away.
The prevent invention is mainly intended for the production of red wine. Here, the fermentation is performed in the presence of grape skins, seeds, and stems. However, it can also be used for white wine production. In white wine production, the crushed grapes (i.e., must) are pressed immediately after crushing and then only the clarified juice is fermented. With the present invention it is possible to fill the fermentation chamber 21 with must and then press immediately by pressurizing chamber 22 as described earlier. The clarified juice can be then be fermented in a fermentation vessel of the same design or in an alternate vessel.
Embodiments of the present invention may also be useful as a container for transporting crushed grapes (i.e., must) from the vineyard to remotely located wineries. The rigid outer container 10 would be suitable for shipment by truck. The inner flexible bag 20 would first be filled with must and inoculated with wine-making yeast. The container could then be shipped in a refrigerated (40-50° F.) state to slow down the metabolism of the yeast. The container with the partially fermented must would then be received at the winery, heated to a normal fermentation temperature (65-80° F.), and the wine fermentation completed as described earlier. Shipment could take up to 5 days, and the container having the vent with a relief valve would exhaust any CO 2 gases that may be generated during shipment.
Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The scope of the present invention is to be limited only by the terms of the appended claims. | A disposable winemaking apparatus for fermenting wine containing skins, seeds, and stems that form a cap includes a single-use, dual chamber plastic bag that incorporates a mechanism to agitate and disperse the cap in order to maximize extraction of color and flavor. It also includes an integral press mechanism to squeeze out the fermented juice through a strainer, retaining the pomace in the disposable bag. The device may also be used for racking and transfer of wine during aging. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of U.S. patent application Ser. No. 09/165,658 filed Oct. 3, 1998.
FIELD OF THE INVENTION
The invention relates to notebook computers and wrist supports.
BACKGROUND OF THE INVENTION
Frequent use of computer keyboards can lead to hand strain and repetitive motion injuries such as Carpal Tunnel Syndrome. To prevent these injuries, cushioned pads have been developed that elevate and support a computer operator's wrists while the operator is using a computer keyboard.
A conventional wrist support pad is typically composed of a moldable, gel-like or sponge-like substance that is encased in a non-porous sheath and supported on its bottom by a rigid or semi-rigid base. It is rectangular in shape with a length generally greater than 18 inches and a width usually between about 3 and 5 inches. The length of the pad is fashioned so that it overlaps or approximates the width of a standard keyboard. The width of the pad is designed to accommodate an average person's wrist. Because conventional wrist support pads are generally not affixed to a keyboard or a computer, they may be placed in any one of a multitude of positions to suit a particular computer operator and/or a particular keyboard.
Although wrist support pads come in a variety of shapes and sizes, most are designed for use with the standard full-size keyboards that are commonly used with desktop computers, and not for the type of keyboards that are integrated within the body of portable notebook computers. Thus, existing wrist support pads are often awkward to use with notebook computers. For example, notebook computers often have keyboards that are placed several inches away from the front edge of the computer body. Positioning a wrist support pad immediately in front of the front edge of the computer body leaves the space between the pad and the keyboard too large for comfortable use by a person with average size hands. Moreover, positioning conventional wrist support pads on top of a notebook computer body immediately in front of the keyboard usually interferes with the use of other functional components of the computer, such as its pointing device (e.g., touchpad or trackball), microphone, or speakers.
SUMMARY OF THE INVENTION
The invention relates to notebook computers having built-in wrist support devices. The invention also relates to wrist support devices that are compatible with conventional notebook computers.
In one aspect, the invention features a notebook computer having a computer body, a keyboard, and a wrist support that is integrated within the computer body. In one variation of this notebook computer, the wrist support is integrated within the top panel of the computer body. In another variation, the wrist support is integrated within the front panel of the computer body.
In preferred embodiments, the notebook computers of the invention feature a wrist support that is reversibly inflatable. Some of these notebook computers further feature an inflation controller that includes a fluid pump and/or a bleed valve. In some variations, these notebook computers also feature an inflation control switch that regulates the inflation controller.
Also within the invention is a wrist support for use with a notebook computer keyboard. This wrist support includes a base having one or more flat surfaces, wherein the largest of these flat surfaces has a surface area of less than about 60 cm 2 . Some embodiments of this wrist support include a fastener for attaching the wrist support to a notebook computer. In the preferred embodiment, this wrist support features a reversibly inflatable bladder.
The invention also features a wrist support kit that includes the aforementioned wrist support with fastener, and an acceptor that can be affixed to a notebook computer in order to supply a connection site for the fastener.
Another feature of the invention is a notebook computer kit that includes a wrist support, a fastener, an acceptor, and a notebook computer. Some embodiments of this notebook computer kit also contain instructions for using (i.e., attaching the wrist support to the notebook computer) the notebook computer kit.
As used herein, the word “keyboard” is used in a generic sense to refer to any device that is used in a repetitive manner to input data into a computer, calculator or like device.
When one object is “integrated” within a second object, it is physically and functionally affixed to and designed to operate in accord with the second object. Thus, when a wrist support is “integrated” within a computer body, it is attached to the computer body in such a manner that both wrist support and computer body operate as one unit.
Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present specification, including definitions will control. In addition, the particular embodiments discussed below are illustrative only and not intended to be limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is pointed out with particularity in the appended claims. The above and further advantages of this invention may be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of one embodiment of the invention;
FIG. 2A is a right side view of the embodiment shown in FIG. 1, shown with the wrist support deflated and the video display support in the closed position;
FIG. 2B is a right side view of the embodiment shown in FIG. 1, shown with the wrist support deflated and the video display support in the open position;
FIG. 2C is a right side view of the embodiment shown in FIG. 1, shown with the wrist support inflated and the video display support in the open position;
FIG. 2D is a side view of the wrist support, inflation controller, and inflation control switch of the embodiment shown in FIG. 1, shown with the wrist support fluidly connected to the inflation controller, and the inflation control switch operatively connected to the inflation controller.
FIG. 3A is a perspective view of another embodiment of the invention, shown with the wrist support panel door in the closed position;
FIG. 3B is a perspective view of the embodiment shown in FIG. 3A, shown with the wrist support panel door in the open position and the wrist support deflated;
FIG. 3C is a perspective view of the embodiment shown in FIG. 3A, shown with the wrist support panel door in the open position and the wrist support inflated;
FIG. 4A is a side view of a detachable wrist support shown in an uninflated position;
FIG. 4B is a side view of the detachable wrist support featured in FIG. 4A shown in an inflated position;
FIG. 4C is a side view of a notebook computer and a detachable wrist support, shown with the wrist support detached from the notebook computer;
FIG. 4D is a side view of a notebook computer and a detachable wrist support, shown with the wrist support attached to the notebook computer and in an uninflated position;
FIG. 4E is a side view of a notebook computer and a detachable wrist support, shown with the wrist support attached to the notebook computer and in an inflated position; and
FIG. 5 is a perspective view of a notebook computer and a detachable wrist support, shown with the wrist support attached to the notebook computer.
DETAILED DESCRIPTION
The invention encompasses notebook computers having an integrated wrist support as well as standard notebook computer components such as a keyboard, pointing device and computer body. As can be seen by comparing different models of currently available notebook computers (e.g., IBM Thinkpad 770™ and Compaq Presario® computers), these standard components may be arranged in myriad different orientations. This notwithstanding, two types of conventional layouts predominate in the marketplace. The first of these has a keyboard oriented on top of the computer body near the video display (see, e.g., FIG. 1 ). This layout features a relatively large unoccupied space on top of the computer body in the area between the keyboard and the front edge of the computer body. A pointing device such as a touchpad is usually located within this space. In the second type of conventional layout, the keyboard is placed on top of and near the front edge the computer body (see, e.g., FIG. 3 A). This layout has only a very small unoccupied space on top of the computer body in the area between the keyboard and the front edge of the computer body.
The below described preferred embodiments illustrate adaptations of wrist supports for use with notebook computers having their components arranged in each of these two conventional layouts. Nonetheless, from the description of these embodiments, other notebook computers of the invention can be readily fashioned by repositioning and/or making slight modifications to the components discussed below.
In brief overview, referring to FIGS. 1, 2 A, 2 B, 2 C, and 2 D, an embodiment of notebook computer 5 includes a computer body 10 having a front panel 11 , side panels 12 (right side panel is shown; left side panel is not shown), a top panel 13 a , a bottom panel 13 b and a back panel 14 ; a video display support 15 containing a video display 16 ; wrist supports 17 a (left) and 17 b (right); a pointing device 18 ; a keyboard 19 ; an inflation controller 20 ; an inflation control switch 21 ; a fluid connector 28 ; and a switch connector 29 .
The notebook computer 5 shown in FIGS. 1, 2 A, 2 B, and 2 C shares many of the same components featured in conventional notebook computers. For example, the bulk of the physical structure of notebook computer 5 consists of computer body 10 and video display support 15 . Each of these serve as a supportive and protective housing for other components of the computer. Both computer body 10 and video display support 15 are typically composed of a hard durable material such as a plastic (e.g., polyvinyl chloride) or a metal alloy (e.g., a magnesium alloy). Computer body 10 has a rectangular polyhedron shape formed by front panel 11 , side panels 12 , top panel 13 a , bottom panel 13 b and back panel 14 . It is movably attached to video display support 15 by a hinge such that video display support 15 can be reversibly positioned immediately on top of and roughly parallel to top panel 13 a (i.e., in the closed position; see FIG. 2A for example) or at various angles away from top panel 13 a (i.e., in an open position; see FIGS. 2B and 2C for example). The interior of computer body 10 houses various functional parts of the computer such as a central processing unit (CPU), a hard drive, a floppy disk drive, a CD-ROM drive, a battery, etc. The exterior of computer body 10 features devices such as pointing device 18 , keyboard 19 , a power switch, a microphone, speakers, etc. Video display support 15 houses video display 16 (e.g., an LCD video monitor) which is operatively linked to other functional parts of the computer. The above features are functionally connected in a similar manner as in conventional notebook computers.
Also included within the notebook computer 5 shown in FIGS. 1, 2 A, 2 B, and 2 C are wrist supports 17 a (left) and 17 b (right), inflation controller 20 , and inflation control switch 21 . In the embodiment shown, wrist supports 17 a (left) and 17 b (right) are integrated into computer body 10 at the portions of top panel 13 a on each side of pointing device 18 in a position immediately forward of keyboard 19 . This orientation is such that the user of notebook computer 5 can comfortably rest his wrists or palms on wrist supports 17 a (left) and 17 b (right) while his fingers are located in a position convenient for typing on keyboard 19 . Wrist supports 17 a and 17 b are basically bladders composed of an elastic material (e.g., latex or synthetic rubber) that are fillable with a fluid such as a gas (e.g., air, carbon dioxide, or nitrogen) and fluidly connected to a fluid source (e.g., atmospheric air) via fluid connector 28 (see FIG. 2 D), a device for transferring fluid from one source to another (e.g., non-porous tubing or the like). They may optionally be covered with fabric (e.g., nylon, polyester, etc.) to enhance their comfort and durability. Each wrist support 17 is reversibly expandible in size by adding or decreasing the amount of fluid contained therein. Wrist supports 17 a and 17 b may be fluidly connected to each other to form one structure (i.e., wrist support 17 ). Alternatively, wrist supports 17 a and 17 b can lack a fluid connection to each other. The latter configuration is preferred where it is desirable to have left and right wrist supports that are independently adjustable.
Inflation controller 20 is a device that regulates the amount of fluid in wrist support 17 . In a preferred embodiment, inflation controller 20 comprises a two-way fluid pump that is mounted at a predetermined location on notebook computer 5 (e.g., on computer body 10 at side panel 12 as shown in FIG. 1 ). In another preferred embodiment, inflation controller 20 comprises a fluid pump and a bleed valve. In either case, as shown in FIG. 2D, the fluid pump (and the bleed valve in the latter configuration) of inflation controller 20 is connected to wrist support 17 and a fluid source (e.g., the air in the atmosphere surrounding notebook computer 5 ) by fluid connector 28 such that the fluid may reversibly flow from the fluid source through inflation controller 20 into wrist support 17 . Where wrist supports 17 a and 17 b are not fluidly connected to each other, inflation controller 20 is separately connected to wrist support 17 a and wrist support 17 b such that it independently controls inflation of each wrist support (e.g., there is a separate fluid pump for each wrist support).
Activation of inflation controller 20 causes fluid to flow through fluid connector 28 between the fluid source (e.g., atmospheric air) and wrist support 17 . Activation of the fluid pump portion of inflation controller 20 in a forward direction causes fluid to move from the fluid source through inflation controller 20 into wrist support 17 , thus inflating wrist support 17 . Activation of the fluid pump of inflation controller 20 in a reverse direction causes fluid to move from wrist pad 17 through inflation controller 20 out to the fluid source (e.g., the atmosphere), thus deflating wrist support 17 . In the configuration of inflation controller 20 that includes a bleed valve, opening the bleed valve causes fluid to flow out of wrist support 17 fluid connector 28 through fluid connector 28 into the atmosphere via inflation controller 20 , thus deflating wrist support 17 . In some configurations, the bleed valve portion of inflation controller 20 can be set to automatically open when a threshold fluid pressure is reached. Thus, when wrist support 17 reaches a certain predetermined size or pressure, the bleed valve opens and thereby releases fluid from wrist support 17 . In this manner, the maximum size to which wrist support 17 can be expanded can be automatically controlled.
Inflation control switch 21 is a switch device that regulates the operation of inflation controller 20 . It is mounted on a predetermined site on notebook computer 5 that is accessible to a user. For example, in the embodiment shown in FIG. 1, inflation control switch 21 is affixed to computer body 10 on top panel 13 a near video display support 15 . As shown in FIG. 2D, inflation control switch 21 is operatively linked (e.g., mechanically, hydraulically, or electrically) to inflation controller 20 via switch connector 29 , a device that operatively links inflation control switch 21 to inflation controller 20 (e.g., an electrical wire, a mechanical cable, or hydraulic hosing). It has an inflate position, a stop position, and a deflate position. When placed in the inflate position, inflation control switch 21 signals inflation controller 20 to activate its fluid pump to send fluid into and thereby inflate wrist support 17 . When placed in the deflate position, inflation control switch 21 signals inflation controller 20 to reverse its fluid pump and/or open its bleed valve to thereby deflate wrist support 17 . When placed in the stop position, inflation control switch 21 signals inflation controller 20 to either stop inflating or stop deflating wrist support 17 .
An overview of the operation of the foregoing preferred embodiment is shown in FIGS. 2A, 2 B, and 2 C. In FIG. 2A, notebook computer 5 is shown in the closed position with wrist support 17 deflated. Deflation of wrist support 17 permits video display support 15 to be placed immediately on top of and roughly parallel to top panel 13 a so that notebook computer 5 is in a compact configuration (i.e., with video display support 15 in the closed position) that enhances the portability of notebook computer 5 . To operate notebook computer 5 , a user moves video display support 15 to an open position such that the user can view video display 16 (see, e.g., FIG. 2B) and then boots up the computer. To utilize wrist support 17 , the user then places inflation control switch 21 in the inflate position, thus activating the fluid pump of inflation controller 20 to send fluid into wrist support 17 via fluid connector 28 . When wrist support 17 is inflated to the desired size (one example is depicted in FIG. 2 C), the user then places inflation controller switch 21 in the stop position to halt fluid flow into wrist support 17 . Thus, in this configuration, the user can operate notebook computer 5 much like a conventional notebook computer except that his wrists or palms are comfortably propped on inflated wrist support 17 . Because wrist support 17 can be inflated to an infinite number of positions up to a maximum inflation position, each different user can adjust the size of wrist support 17 to his liking.
When the user has completed operating notebook computer 5 , he can restore it to the compact and portable configuration shown in FIG. 2A by placing inflation control switch 21 in the deflate position. In this position, inflation control switch 21 causes deflation of wrist support 17 by activating the fluid pump of inflation controller 20 to remove the fluid from wrist support 17 and/or opening the bleed valve portion of inflation controller 20 to thereby release the fluid from wrist support 17 . In some variations of this embodiment, the user can apply pressure to wrist support 17 (e.g., by manually squeezing wrist support 17 ) to hasten the release of fluid from (and thus deflation of) wrist support 17 . When a sufficient amount of fluid is removed from support 17 , inflation control switch 21 is placed in the stop position. The user can then place video display support 15 immediately on top of and roughly parallel to top panel 13 a (FIG. 2 A).
In another variation of this preferred embodiment, operation of inflation control switch 21 is automatic or semiautomatic. For example, as shown in FIGS. 1, 2 A, 2 B, and 2 C, inflation control switch 21 is positioned on top panel 13 a adjacent to video display support 15 . In this variation, inflation control switch 21 is designed as a pushbutton-type device (e.g., a spring-loaded piston movably mounted within an open-ended cylinder) that has a depressed position where the top of the pushbutton is approximately flush with the surface of top panel 13 a , and non-depressed positions where the pushbutton extends perpendicularly away from top panel 13 a for various short distances (such as 0.5, 1, or 2 cm) up to a maximum non-depressed position in which the pushbutton is fully extended. The pushbutton-type device is biased so that it is in the maximum non-depressed position in the absence of extraneous forces.
When the video display support of notebook computer 5 is in the closed position (such as shown in FIG. 2 A), the pushbutton of inflation control switch 21 is held in the depressed position by contact from a portion of video display support 15 . This position corresponds to the stop position discussed above (i.e., inflation controller 20 is inactivated). When video display support 15 is placed in an open position, the pushbutton of inflation control switch 21 rises to a non-depressed position as a result of its bias. This movement from a depressed position to a non-depressed position places inflation control switch 21 in the inflate position and thereby signals inflation controller 20 to send fluid into wrist support 17 . After wrist support 17 reaches a preset inflation level, inflation controller 20 automatically returns to an inactivated state (e.g., inflation controller 20 has a pressure sensor that turns off the fluid pump of inflation controller 20 when a threshold pressure is detected). Because the pushbutton of inflation control switch 21 abuts against a portion of video display support 15 , lowering video display support 15 to return it to the closed position gradually pushes inflation control switch 21 downward toward the depressed position. This downward push places inflation control switch 21 in the deflate position and thereby signals inflation controller 20 to remove fluid from wrist support 17 . With wrist support 17 deflated, video display support 15 can be returned to the closed position in which inflation control switch 21 is in the depressed or stop position.
Another preferred embodiment of the invention is shown in FIGS. 3A, 3 B, and 3 C. Similarly to the notebook computer discussed above and shown in FIGS. 1, 2 A, 2 B, 2 C and 2 D, this embodiment is a notebook computer that includes a computer body 10 having a front panel 11 , side panels 12 (right side panel is shown; left side panel is not shown), a top panel 13 a , a bottom panel 13 b (not shown) and a back panel 14 (not shown); a video display support 15 containing a video display 16 ; a wrist support 17 ; a keyboard 19 ; an inflation controller 20 ; an inflation control switch 21 ; a fluid connector 28 (not shown); and a switch connector 29 (not shown). To illustrate how the above components of the notebook computers of the invention can be arranged in different orientations, notebook computer 5 in FIG. 1 can be compared to notebook computer 5 in FIG. 3 A. For example, in the embodiment shown in FIG. 3A, keyboard 19 is oriented closer to front panel 11 than in the embodiment shown in FIG. 1 . Likewise, inflation control switch 21 is mounted on top panel 13 a near front panel 11 in the embodiment shown in FIG. 3A, whereas it is mounted near video display support 15 in the embodiment shown in FIG. 1 .
In the embodiment shown in FIGS. 3A, 3 B, and 3 C, wrist support 17 of notebook computer 5 is contained within computer body 10 immediately behind front panel 11 . This embodiment is preferred for notebook computers having a keyboard placed on top panel 13 a at a location near front panel 11 (e.g., IBM Thinkpad 770™) as the lack of available space on the portion of top panel 13 a in front of keyboard 19 does not limit placement of wrist support 17 . This embodiment optionally features a wrist support panel door 22 that is composed of a material similar to that composing computer body 10 (such as plastic or metal). Wrist support panel door 22 is typically rectangular in shape, and attached to and integrated within front panel 11 . As an example, FIGS. 3A and 3B show wrist support panel door 22 hingedly attached to the bottom of front panel 11 . Wrist support panel door 22 has a closed position and open positions. In the closed position, wrist support panel door 22 is reversibly locked into computer body 10 by wrist support panel door clasp 22 a (any number of such clasps can be used; FIG. 3A shows two such clasps). One open position of wrist support panel door 22 is shown in FIG. 3 B. Although wrist support panel door 22 is not required for the function of this embodiment, it is generally a preferred component as it protects wrist support 17 from damage and provides a convenient mechanism for storing wrist support 17 while it is not being used. One exemplary alternative configuration of this embodiment (not shown) has wrist support 17 integrated into computer body 10 at front panel 11 with front panel 11 having a cut-out portion through which wrist support 17 can expand. This configuration resembles notebook computer 5 shown in FIG. 3B that wrist support panel door 22 is omitted.
In the preferred embodiment, wrist support 17 is a single unit (albeit, multiple wrist supports could also be used) that is essentially a bladder composed of an elastic material (e.g., latex or synthetic rubber). This bladder is fillable with a fluid such as a gas (e.g., air, carbon dioxide, or nitrogen) and fluidly connected to a fluid source (e.g., atmospheric air) via fluid connector 28 (not shown, but see FIG. 2D for a similar example), so that wrist support 17 can be reversibly expanded by adding or decreasing the amount of fluid contained therein. Wrist support 17 is shaped (e.g., the elastic material is pre-molded) so that when expanded it develops a shape conducive for comfortable typing by an operator of the notebook computer. It may optionally be covered with fabric (e.g., nylon or the like) to enhance its feel (i.e., comfort for a user) and/or durability.
The components of this embodiment function quite similarly to the components of the embodiment shown in FIGS. 1, 2 A, 2 B, and 2 C. For example, in this embodiment, inflation controller 20 also comprises a two-way fluid pump (or a fluid pump and a bleed valve) that is mounted at a predetermined location on notebook computer 5 . It is also connected to wrist support 17 and a fluid source (e.g., the air in the atmosphere surrounding notebook computer 5 ) via fluid connector 28 (not shown) such that the fluid can reversibly flow from the fluid source through inflation controller 20 into wrist support 17 . Activation of the fluid pump portion of inflation controller 20 in a forward direction causes fluid to flow into (and thereby inflate) wrist support 17 . Reversing the direction of the fluid pump removes fluid from (and thereby deflates) wrist pad 17 . Where a bleed valve is included as part of inflation controller 20 , opening the bleed valve causes fluid to flow out of (and thereby deflate) wrist support 17 .
This embodiment also features an inflation control switch 21 for regulating the operation of inflation controller 20 . It is placed at a predetermined site on notebook computer 5 (in FIGS. 3A, 3 B, and 3 C it is shown on top panel 13 a near front panel 11 and right side panel 12 ), and is operatively linked to inflation controller 20 via switch connector 29 (not shown; but see FIG. 2D for a similar example). It has an inflate position, a stop position, and a deflate position. When placed in the inflate position, inflation control switch 21 signals inflation controller 20 to activate its fluid pump to send fluid into and thereby inflate wrist support 17 . When placed in the deflate position, inflation control switch 21 signals inflation controller 20 to reverse it fluid pump and/or open its bleed valve to thereby deflate wrist support 17 . When placed in the stop position, inflation control switch 21 signals inflation controller 20 to either stop inflating or stop deflating wrist support 17 .
The operation of this preferred embodiment is very similar to the operation of the embodiment shown in FIGS. 2A, 2 B, 2 C, and 2 D. In FIG. 3A, notebook computer 5 is shown with wrist support 17 deflated and wrist support panel door 22 in the closed position. To inflate wrist support 17 , the user first opens wrist support panel door 22 and then places inflation control switch 21 in the inflate position, thus activating the fluid pump of inflation controller 20 to send fluid into wrist support 17 . In one variation of this embodiment, wrist support panel door clasp 22 a can be designed so that wrist support panel door 22 automatically opens while wrist support 17 is being inflated. For example, wrist support panel door clasp 22 a can be a hook and loop-type connector (e.g., Velcro®) that comes apart when subjected to a predetermined force such as the pressure caused by the inflation of wrist support 17 . When wrist support 17 is inflated to a desired size (e.g., as depicted in FIG. 3 C), the user then places inflation controller switch 21 in the stop position to cut off fluid flow into wrist support 17 . To restore the compact and portable configuration of notebook computer 5 (as shown in FIG. 3 A), inflation control switch 21 is placed in the deflate position. This causes inflation controller 20 to remove the fluid from wrist support 17 as described supra. In some cases, the user can apply pressure to wrist support 17 to hasten deflation of wrist support 17 . When a sufficient amount of fluid is removed from wrist support 17 , inflation control switch 21 can be placed in the stop position. The deflated wrist support 17 can be stowed in computer body 10 and secured by closing wrist support panel door 22 .
As shown in FIGS. 4A, 4 B, 4 C, 4 D, 4 E, and 5 , another preferred embodiment of the invention is a wrist support that is detachably affixable to the body of a notebook computer. In this embodiment, wrist pad 17 includes an inflation controller 20 , a base 23 , a bladder 24 , bladder cover 25 , and a fastener 26 . To facilitate compatibility with notebook computers, the total area of the largest flat surface of wrist pad 17 is less than about 60 cm 2 (e.g., 25, 30, 45, 50, or 55 cm 2 ). The specific dimensions and shape of wrist pad 17 can be chosen to match the particular layout of a given notebook computer.
Although, in some embodiments, base 23 can be used alone as a wrist support (especially if base 23 is composed of a soft, compressible material such as synthetic sponge), in the particular embodiment shown in FIGS. 4A, 4 B, 4 C, 4 D, 4 E, and 5 , base 23 is a structure that forms and maintains the shape of the bottom portion of wrist pad 17 . It is roughly rectangular in shape and composed of a rigid or semi-rigid material such as plastic or reinforced rubber. Base 23 also serves as a structure on which to mount other components of wrist pad 17 such as bladder 24 , bladder cover 25 , and/or fastener 26 .
Bladder 24 is fixedly attached to base 23 . It is essentially an elastic balloon (e.g., a latex or synthetic rubber balloon) that is fillable with a compressible substance such as a gas (e.g., air, carbon dioxide, or nitrogen) or a sponge-like material. By adding or decreasing the amount of compressible substance contained within bladder 24 (e.g., via a connection to a source of said substance), wrist support 17 can be reversibly expanded.
In a preferred configuration of this embodiment, the compressible substance is atmospheric air. In this configuration, bladder 24 is biased so as to be in an expanded configuration when not subjected to an extraneous force (much like the inflation bulb in a standard manual sphygmomanometer). Bladder 24 communicates with the atmosphere via inflation controller 20 , which in this embodiment is a valve directly attached to bladder 24 that has an open and a closed position. When inflation controller 20 is in the open position, air from the atmosphere can flow in and out of bladder 24 . When inflation controller 20 is in the closed position, air from the atmosphere cannot flow in or out of bladder 24 . Because of bladder 24 's bias, when inflation controller 20 is in the open position bladder 24 is in an inflated state (see FIG. 4 B). When the inflation controller 20 is then placed in the closed position, air cannot escape bladder 24 , and thus wrist support 17 is stabilized in the inflated state. When inflation controller 20 is left in the open position, a user can compress (e.g., by manually squeezing) bladder 24 to a desired inflation state and then close inflation controller 20 so that the chosen state is stabilized (see FIG. 4 A).
Similarly, a user can partially or completely deflate wrist support 17 by partially or fully compressing bladder 24 . This deflated state can be stabilized by either continuing the compressing force, or by placing inflation controller 20 in the closed position. In this manner the size of wrist support 17 can be minimized to facilitate its portability and/or storage. In some variations, wrist support 17 can be deflated while attached to a notebook computer so that the video display support of the notebook computer can be placed in the closed position without wrist support 17 being detached.
Other components of the wrist support device shown in FIGS. 4A, 4 B, 4 C, 4 D, 4 E, and 5 include bladder cover 25 , fastener 26 , and acceptor 27 . Bladder cover 25 is a piece of fabric (e.g., nylon or the like) that is placed over bladder 24 (as shown in FIGS. 4A and 4B) in order to reinforce and protect bladder 24 , and/or to enhance the esthetics or feel (for user comfort) of wrist pad 17 . Fastener 26 and acceptor 27 are devices used for attaching wrist support 17 to notebook computer 5 .
Fastener 26 is attached to the bottom portion of wrist support 17 . It can be any type of device that can mediate the attachment of wrist support 17 to the surface of computer body 10 (e.g., an adhesive tape, a magnet, or a mechanical lock). In the preferred embodiment shown in FIGS. 4A, 4 B, 4 C, 4 D, and 4 E, fastener 26 is a one component of a hook and loop-type connector such as Velcro® (i.e., fastener 26 is the hook or the loop component of the connector). In this configuration, to affix wrist support 17 to notebook computer 5 , acceptor 27 is first mounted (e.g., using an adhesive) to an unoccupied area on the surface of computer body 10 (see FIG. 4 C). Acceptor 27 is one component of a two component connector (e.g., a hook and loop-type connector) that is attachable to fastener 26 . For example, in the preferred embodiment, where fastener 26 is the hook component of a hook and loop-type connector, acceptor 27 will be the loop component of the connector, and vice versa. As shown in FIG. 4D, wrist support 17 is then placed onto notebook computer 5 so that fastener 26 engages acceptor 27 . Wrist support 17 is thus affixed to the notebook computer (see FIG. 4D for a side view and FIG. 5 for a perspective view). While in this position wrist support 17 can be in a deflated position (FIG. 4D) or an inflated position (FIG. 4 E). Wrist pad 17 can be removed from notebook computer 5 by simply prying it from the surface of computer body 10 with sufficient force to disengage fastener 26 from acceptor 27 .
From the foregoing, it can be appreciated that the notebook computers and wrist supports of the invention permit the use of a keyboard in a comfortable and ergonomic manner.
While the above specification contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as examples of preferred embodiments thereof. Many other variations are possible. For example, a notebook computer having an inflatable wrist support integrated into the top panel of the computer body wherein inflation of the wrist support causes it to expand in such a manner as to overlap the front panel of the computer body, is included within the invention. As another example, a notebook computer having a wrist support in communication with a self-contained, pressurized fluid reservoir (e.g., a tank containing pressurized nitrogen gas) such that the fluid reservoir can provide fluid to inflate the wrist support is within the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents. | Notebook computers having an integrated wrist support device are disclosed. Also disclosed are wrist supports for use with notebook computer keyboards, a wrist support kit, and notebook computer kits. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 USC §119 of European Application EP. No. 05026541.1 filed 24 Nov. 2005, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to an inspection system for the automatic inspection of ophthalmic lenses, preferably in an automated lens manufacturing line. The inspection system provides a phase contrast imaging unit and an inspection method using said phase contrast imaging unit designed to recognize defective lenses with an improved degree of reliability but that does not falsely sort out perfect lenses.
BACKGROUND OF THE INVENTION
Contact lenses from a wide range of materials are nowadays produced in great volume in highly automated manufacturing facilities. Advantageously, these contact lenses are formed using reusable mould halves, the female and the male, which are normally formed from glass or quartz. When mated (mould assembly), these mould halves define a hollow cavity, which corresponds to the subsequent contact lens shape. Before closing the mould halves, a polymer solution is dosed into the female mould half. After closing the mould halves, UV light is radiated over a mould half, which leads to crosslinking of the lens material in the lens cavity. Subsequently, the lens is removed from the mould half, for example with suction grips or mechanical grippers, and placed in the package.
Because contact lenses are intended for use in the eye, great care is taken to make sure that lenses meet strict quality control standards. To ensure consistent quality of the contact lenses, automatic inspection of the contact lenses using industrial image processing methods may be implemented. The known methods for inspection of ophthalmic lenses are based on bright-field and/or dark-field imaging.
WO-A-2005/054807 discloses a method for the automatic inspection of contact lenses, in particular tinted contact lenses, in an automatic lens manufacturing process, the method comprising the use of a dark-field inspection unit with the preferred dark-field inspection method being the so-called Schlieren method.
EP-A-1248092 further discloses the combination of a dark-field inspection unit and a bright-field inspection unit, preferably the combination of the so-called Schlieren method and the transmitted light method. The contact lens is subsequently observed in a dark-field and bright-field.
WO-A-2004/057297 discloses a method for optically inspecting and detecting defects in an object using two different light sources, in particular using a dark-field setup as the first detection method and a bright-field setup as the second detection method.
WO-A-03/073060 discloses the dual inspection of ophthalmic lenses using at least two different machine vision inspection techniques in the manufacturing process for said ophthalmic lenses, the preferred at least two inspection techniques being bright field and dark field inspection techniques; others being absorptive inspection, structure light inspection, fluorescence inspection and spectral masking.
WO-A-99/32869 discloses a system for inspecting contact lenses which utilizes a light source and an electronic camera for obtaining images of the lens, as well as a series of masks, including a bright-field mask, a dark-field mask and a transition mask which is constituted by fine stripes, such that the light interacts in a constructive and destructive manner at different distances from the mask. The images are taken subsequently using one mask at a time.
EP-A-0686842 discloses a lens inspection system and method using two optimized bright-field illumination zones, i.e. using light at two different grey levels. One grey level for the centre zone and one grey level for the peripheral zone. Whereas the use of phase contrast (another conceivable inspection method) is considered to be hypersensitive, i.e. enhancing cosmetic flaws to an extent that the lens is rejected for being defective.
To improve production yield and more importantly to improve the quality of the ophthalmic lens and the wearers comfort, there is a need to create a more accurate inspection system. In particular, a suitable inspection system should carry out an exhaustive examination of the ophthalmic lenses for accuracy of size, surface defects, tears, peripheral ruptures and inclusions such as bubbles and foreign bodies, as well as small defects at the edges of an ophthalmic lens.
SUMMARY
The invention solves this problem with the features indicated in claim 1 . As far as further essential refinements are concerned, reference is made to the dependent claims.
In one aspect the invention provides a method for inspecting an ophthalmic lens comprising using a phase contrast imaging unit. Preferably the method further comprises using a bright field and/or dark field imaging unit. Even more preferably the method allows selectively employing either the phase contrast and bright-field imaging unit or the phase contrast and dark-field imaging unit. Further preferably the method allows simultaneously employing the bright-field imaging unit and the phase contrast imaging unit.
In another aspect the method of the invention allows simultaneously employing the dark field imaging unit and the phase contrast imaging unit.
In a more preferred aspect, the method is an automatic inspection method in an automated lens manufacturing line.
In another aspect the invention provides an inspection device for the automatic inspection of ophthalmic lenses, in an automated lens manufacturing line comprising a phase contrast imaging unit. Preferably, the device further comprises a bright-field imaging unit and/or a dark-field imaging unit. Even more preferably the device allows selectively employing either the phase contrast and bright-field imaging unit or the phase contrast and dark-field imaging unit. Further preferably the device allows simultaneously employing the bright-field imaging unit and the phase contrast imaging unit. In another aspect the device allows simultaneously employing the dark field imaging unit and the phase contrast imaging unit.
In still another aspect, the present invention may include devices and methods to improve the inspection of tinted or colour contact lenses
Further details and advantages of the invention may be seen from the description and the drawings that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic illustration of an inspection device comprising a phase-contrast imaging unit according to the invention.
FIG. 2 shows a bright-field image of a contact lens.
FIG. 3 shows a dark-field image of a contact lens.
FIG. 4 shows a phase contrast image of a contact lens.
FIGS. 5 a - c show a comparison of a bright-field (a), a dark-field (b) and a phase contrast (c) image of a defective lens.
FIGS. 6 a - c show another comparison of a bright-field (a), a dark-field (b) and a phase contrast (c) image of a defective lens.
FIGS. 7 a & b show a comparison of a bright-field (a) and a phase contrast (c) image of a defective toric lens.
FIGS. 8 a - c show a comparison of a bright-field (a), a dark-field (b) and a phase contrast (c) image of a toric lens.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention ophthalmic lenses are inspected by an inspection method comprising using a phase contrast imaging unit. In alternative embodiments, bright field and/or dark-field imaging may be used to supplement the phase contrast imaging.
The phase contrast technique, as generally known, employs an optical mechanism to translate minute variations in phase into corresponding changes in amplitude, which can be visualized as differences in image contrast. Further, it is known, that phase contrast imaging can be employed as a technique to render a contrast-enhancing effect in imaging transparent specimen.
Contrary to references in the prior art, which consider phase contrast imaging hypersensitive and therefore unsuitable for inspection of ophthalmic lenses, it has surprisingly been found, that phase contrast imaging is in fact suitable for the inspection of ophthalmic lenses and provides for an accurate inspection system. It has further been found, that in particular the combination of phase contrast imaging with either bright-field or dark-field imaging provides a more accurate inspection system. Even further it has been found, that using phase contrast imaging and bright-field imaging simultaneously provides an even more accurate inspection system.
The phase contrast imaging method for inspecting an ophthalmic lens as of the present invention is based on the transformation of refractive index differences into intensity differences whereas bright-field imaging is based on absorption differences. In a preferred aspect of the invention both imaging methods are combined and applied simultaneously.
The basis of the transformation for the phase contrast imaging is the interference property. The result of interference of two waves of light depends upon their phase relationship. There are two extremes. If the two waves meet in exactly the same phase they will interfere in a completely constructive manner, i.e., they will be additive and the intensity of light that results will be the sum of the intensities of the interfering waves. If the two interfering waves are one-half wavelength out of phase, the interference will be totally destructive and the two waves will cancel out. Any other phase relationship will produce intermediate intensity.
The phase contrast imaging unit of the present invention accomplishes two tasks that the bright-field observation alone does not: it separates the background light from the light scattered by the specimen (i.e. the contact lens), and it causes the scattered and unscattered waves to be approximately one-quarter or one-half a wavelength out of phase with each other so that they can destructively interfere and cause changes in intensity.
The phase contrast imaging unit for inspecting an ophthalmic lens of the present invention differs from inspection units known from the prior art by having a phase plate between the specimen and the detector. Any background light which is not deviated or scattered by the specimen passes though the phase plate. When the deviated and undeviated beams of light are recombined further along the light path, the differences in the phase of the deviated and undeviated light beams become additive or subtractive. The resulting wave is the sum of the two waves which have their crests and troughs opposite each other. The resulting wave is up to four times darker than the background. Therefore the specimen appears darker than the background and features on the specimen will be either lighter or darker than the surrounding field. The resulting image, when viewed by a user, or analyzed by a computer program, makes tears and other small defects visible.
It has to be noted, that the present invention is directed to a phase contrast imaging method and system. Therefore, the phase of the light is not analyzed as such (as for example in U.S. Pat. No. 5,066,120), but the difference of intensity due to in-phase or phase-shifted interference is captured as an image. Only then, said image is used for detecting accuracy of size, surface defects, tears, peripheral ruptures and inclusions such as bubbles and foreign bodies, as well as small defects at the edges.
An inspection device according to one embodiment of the invention is illustrated in FIG. 1 and preferably consists of a phase contrast inspection unit 1 and bright-field inspection unit 2 . The contact lens 3 , which is preferably a soft contact lens, is held in a container 4 .
In the phase contrast inspection unit 1 , a phase plate 9 is mounted in or near the objective rear focal plane (see enlarged part of FIG. 1 ) in order to selectively alter the phase and amplitude of the surround (or undeviated) light passing through the specimen.
A phase plate typically is made of a phase retarding material, such as a dielectric thin film on a glass plate 10 . Most available phase plates are produced by vacuum deposition of thin dielectric and metallic films onto a glass plate or directly onto a lens surface. The role of the dielectric thin film is to shift the phase of light, while the metallic film attenuates undiffracted light intensity.
A “positive” phase plate produces dark contrast and contains a partially absorbing film designed to reduce the amplitude of the surround wavefront. In addition, this plate contains phase retarding material designed to shift (retard) the phase of the diffracted light by 90 degrees.
A “negative” phase plate also contains both phase retarding and partially absorbing materials. However, in this case, both materials are sandwiched within the phase plate so that the undiffracted surround wavefront is the only species affected (attenuated and retarded in phase by 90 degrees).
In optical terminology, phase plates that alter the phase of surround light relative to diffracted light by 90 degrees (either positive or negative) are termed quarter wavelength plates because of their effect on the optical path difference. As a general rule, when objective numerical aperture and magnification is increased, the phase plate width and diameter both decrease.
In one embodiment of the phase contrast inspection unit, the thin phase plate contains a ring etched into the glass that has reduced thickness in order to differentially advance the phase of the surround wave by a quarter-wavelength. In another preferred embodiment the ring is further coated with a partially absorbing metallic film to reduce the surround light amplitude by 60 to 90 percent.
Because the rear focal plane usually resides near an internal lens element, some phase contrast objectives are produced by actually etching into the surface of a lens.
Referring back to FIG. 1 , the contact lens 3 is preferably at least temporarily housed in a container 4 that is transparent at least at the bottom to allow the illumination beam coming from the light source 5 to be transmitted trough the contact lens 3 . The container 4 may be open at the top or closed by means of a transparent window. In use, the container 4 is preferably at least partially filled with a fluid solution, such as, for example, water or saline solution or a similar test liquid. Preferably, the shape of the container is such that, when a contact lens is placed in the container the container tends to centre the lens automatically therein at its bottom. The container may stand alone on the transport subsystem or may be part of a lens carrier provided to hold a multitude of containers.
The light source 5 is used to illuminate the contact lens 3 and may be any suitable kind of monochromatic light source generating either a continuous illumination beam or a serious of flashes or pulses. In the latter case the inspection system preferably further includes a synchronization or coordination mechanism between the transport subsystem and the light source which takes care that the light source is activated exactly when the contact lens is in the inspection position.
Examples of preferred light sources are light emitting diodes (LEDs) or short arc-xenon flash lamps. Other types of light sources, such as halogen lamps may be used, in which case a filter may be used to create monochromatic light. The light emanating from the light source 5 is then collimated by a suitable lens 6 .
To increase the output of light or light intensity, a concave mirror (not shown) may be used. The light reflected by the light source 5 and the concave mirror is then focused onto an input diaphragm (not shown), in a preferred embodiment by a heat filter and a biconvex lens (not shown). The diaphragm lies in the focus point of a further lens, so that the light emanating from the light source 5 is collimated and parallel light is present in the examining zone. It is also possible for an interference filter (not shown) to be additionally used behind the lens 6 , in order to substantially increase the length of coherence of the light emanating from the light source 5 .
The illumination beam transmitted through the contact lens 3 is incident on an imaging convex lens 7 . Past the lens 7 the illumination beam is divided by a beam splitter 8 , e.g. a beam-dividing cube. One beam is that of the phase contrast optics and the other beam is given in transmitted light (i.e. directed to the bright field optics).
In an alternative embodiment, the beam splitter may be used in the same way to direct one beam to the phase contrast optics and the other beam to a dark field optics. In another embodiment, the beam splitter may be used to direct one beam to the phase contrast optics and the other beam to a bright and dark field optics.
The imaging units are each completed by a lens 14 and 16 and a CCD camera 15 and 17 .
For the illumination beam and the observation beam, achromatic lenses are preferably used, in order to avoid aberrations. Observation is preferably carried out under a small angle.
For an extensive and thorough inspection of contact lenses, in particular tinted contact lenses, a dark-field inspection unit may be used in combination with a bright-field inspection unit and/or a phase contrast imaging unit which more easily recognizes linear surface defects outside the iris print. This dark-field method, characterized by the fact that a beam stop is positioned between the contact lens and the camera was introduced by A. Toepler to examine lenses and it is known in literature as Schlieren method. Schlieren systems are especially effective in detecting cosmetic defects such as surface defects, tears, ruptures and inclusions such as bubbles and foreign bodies.
In an embodiment additionally using dark field imaging, the phase retarding plate 9 may be complemented by a beam stop 13 in the filter plane 12 (both not shown in FIG. 1 ). Beam stop 13 should advantageously be of larger diameter than the input diaphragm (not shown in FIG. 1 ), so that the illuminating part of the beam is fully scattered by the imaging properties of the contact lens 3 despite deviations in the illuminating beam. Of course, the beam stop 13 should not be too large, because a disadvantageous number of low frequency parts may be filtered out. Finally, the deviation of the scattered beam is small as compared to the direction of the beam. Using computer-assisted simulation of the path of the beam and the confirmation from the experiments, with an input diaphragm of 1 mm, the size of the beam stop 13 is advantageously 2-3 mm.
In the absence of scattering or refraction of the illumination beam by the contact lens 3 , no light is transmitted past the stop 13 and to the CCD camera 17 , and the resulting picture is completely dark, with the exception of features of a contact lens that deflect light enough to miss the stop 13 . Such features will cause some light to be incident on the pixel array of camera 17 . An image of the incident light is preferably taken by a lens 16 of camera 17 for analysis.
FIGS. 2 to 4 show a bright-field ( FIG. 2 ), a dark-field ( FIG. 3 ) and a phase contrast image ( FIG. 4 ) of a contact lens in high resolution. In FIGS. 5 to 8 , the images of lens specimen obtained with bright-field, dark-field and phase contrast imaging are compared.
FIG. 5 features a lens with a bubble in the lens material (X) as well as with an adhering air bubble on the surface of the lens (O). The latter (O) is not a lens defect, whereas the bubble in the lens material (X) is a lens defect which has to be identified by the system and method of the present invention to reject the lens as defective. FIG. 5 a is the bright-field image, FIG. 5 b is the dark-field image and FIG. 5 c is the phase contrast image of the same lens. Only the phase contrast image allows to distinguish X from O, as X shows a bright halo around the defect, whereas O only appears as a black spot. In a combined bright-field and phase contrast imaging method, the first bright-field image ( FIG. 5 a ) can be used to identify the area for potential defects, which then is either confirmed or disapproved by the subsequent or simultaneous second phase contrast image ( FIG. 5 c ).
FIG. 6 features a lens with two bubbles in the lens material (X), both appearing with a bright halo in the phase contrast image. One of them is poorly visible in FIG. 6 a , whereas it is clearly visible in FIG. 6 b . Here the first dark-field image ( FIG. 6 b ) can be used to identify the area for potential defects, which then is either confirmed or disapproved by the subsequent or simultaneous second phase contrast image ( FIG. 6 c ).
FIG. 7 shows a comparison of a bright-field and a phase contrast image taken simultaneously of the same toric lens. In FIG. 7 a the bubble in the lens material (X) appears undistinguishable from an adhering air bubble on the surface of the lens ( 0 ) as in the previous images. Whereas in FIG. 7 b the bright halo reveals the true nature of the defect to reject the lens. Here again either phase contrast image ( FIG. 7 a ) alone or the combination with the bright-field image ( FIG. 7 b ) would allow to reliably reject a lens (and only a lens) with true defects.
FIG. 8 shows three images of a toric lens, i.e. a lens where the orientation on the eye is essential for the effective vision correction. Neither the bright-field ( FIG. 8 a ), nor the dark-field ( FIG. 8 b ) image allow to capture the orientation of the lens in the package. However, the phase contrast image ( FIG. 8 c ) clearly reveals the underlying optical design and the respective orientation of the lens.
The present invention is preferably used on a manufacturing line. By an appropriate transport subsystem in a production plant, the specimen (contact lens) is moved along a predetermined path into the lens inspection position wherein one lens at the time is inspected. Preferably the lens is continuously moving through the inspection system, however the lens may also be in a stationary position during the inspection.
Because the resulting dark-field image is not affected by any object in or within the lens which absorbs light such as an iris print, this method is particularly effective to inspect tinted contact lenses. Cosmetic defects which may be hidden by the iris print become clearly detectable.
Regardless of whether phase contrast imaging, phase contrast and bright-field imaging or phase contrast and dark field imaging are used, the image is automatically processed by a computer which decides whether to reject the lens or process it further according to preset selection criteria by any known method in the art.
The methods described above are suitable to inspect any kind of ophthalmic lenses, in particular contact lenses. Preferably the contact lens is a soft contact lens for example a conventional hydrogel lens which comprises for example a poly-HEMA homo or copolymer, a PVA homo or copolymer, or a crosslinked polyethylenglycol or a polysiloxane hydrogel. In a more preferred embodiment the contact lens is a tinted contact lens. | The present invention relates to an inspection system for the automatic inspection of ophthalmic lenses, preferably in an automated lens manufacturing line. The inspection system provides a phase contrast imaging unit and an inspection method using said phase contrast imaging unit designed to recognize defective lenses with an improved degree of reliability but that does not falsely sort out perfect lenses. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to lockers and, more particularly, to weather resistant coin operated lockers.
2. Description of the Invention Background
A variety of different methods and apparatuses have been developed for securing personal possessions in public areas. One apparatus that has been developed is a coin operated locker for storage of personal possessions. Such a locker commonly includes two vertical parallel side panels, a vertical rear panel attached to both side panels, a top and a bottom, thereby creating a storage compartment enclosed on five sides. The front of the locker typically has at least one lockable door. A front-mounted coin operated locking mechanism and a coin receptacle located beneath the locking mechanism in a channel are also common components of such lockers. The walls and door of lockers are typically fabricated from flat rolled steel, welded by a skilled mechanic, and arranged along horizontal and vertical planes. The locking mechanism in a typical application maintains the door in an unlocked condition until a coin is inserted therein. Once a coin is inserted into the locking mechanism, a key in the locking mechanism may be rotated to lock the door and then the key may be removed. The key must then be reinserted in the locking mechanism to unlock the door. When placed in the unlocked position, the key of the typical locking mechanism may not be removed unless another coin is inserted. The coin receptacle is typically situated alongside the storage compartment or beneath the storage compartment. Coins that are inserted into the locking mechanism are directed into the coin receptacle where they accumulate until they are periodically removed. Such lockers are commonly found grouped together to provided many separate storage compartments for use by a number of people. Such lockers, however, are not suitable for outdoor use because their steel construction deteriorates rapidly in such conditions. Such steel lockers are, furthermore, disadvantageously heavy and expensive to fabricate. Front-mounted locking mechanisms are disadvantageous because they may be vandalized by prying. In addition, a channel-mounted coin receptacle is disadvantageously small and, thus, will overflow unless emptied regularly. The time and skill required to weld a locker together is another disadvantage of a conventional locker.
Another common problem with known lockers is that they often become soiled by way of spills that occur therein, by foods that melt and stick to the compartment or by other means. Such soiling often prevents a locker from being reused until the soiling has been discovered and removed because items placed in a soiled locker may in turn be soiled. Known lockers are also disadvantageously difficult to clean. Pressurized water generally may not be directed into previous steel structures because of the potential for rusting of the structure, particularly in areas that cannot be easily dried. In addition, previous structures having a flat lower surface or shelf tend to retain spilled material and other impurities thereon. Furthermore, when a flat shelf becomes soiled, other items placed on that soiled shelf are likely to become soiled themselves, thereby placing the soiled locker, for all practical purposes, unusable until the impurities are discovered and removed.
Therefore, there is a particular need for a locker that is suitable for outdoor use. There is also a need for a locker having a locking mechanism that is not susceptible to prying. There is, furthermore, a need for a locker that has a large coin receptacle that is not prone to overflowing. There is also a particular need for a locker that prevents spilled material and other forms of impurities in the locker from contacting personal possessions later placed in the locker. There is also a need for a locker that may be easily cleaned by directing pressurized water from a hose or other device into the locker storage compartment. There is additionally a need for a locker having a storage compartment that is configured such that liquids spilled or sprayed in the compartment will drain from the compartment. There is also a need for a locker that is strong, lightweight, and that may be produced inexpensively.
SUMMARY OF THE INVENTION
In accordance with a particularly preferred form of the present invention, there is provided a locker. The locker comprises a first side wall having an interlocking portion, a second side wall having a first interlocking portion engaging the interlocking portion of the first side wall and a second interlocking portion, and a third side wall having an interlocking portion engaging the second interlocking portion of the second side wall. The locker may also have at least two side walls that are cut from the same stock.
A coin receptacle for a coin operated locker is also provided. The coin receptacle comprises a channel having a cross-section and at least one coin operated locking mechanism, and defining an opening through which coins may fall, and a coin tray disposed below the channel having a cross-section greater than that of the channel. In a particular embodiment, the coin receptacle may further comprise a coin deflector mounted in the channel for deflecting coins into the coin tray.
A coin receptacle locking mechanism for mounting on a frame is also provided. The coin receptacle locking mechanism comprises a key operated barrel, a cam attached to the barrel, and a lock bar attached to the cam. The cam includes at least three lobes, wherein the first lobe engages the frame at a first point, the second lobe engages the frame at a second point, and the third lobe is pivotaly connected to the lock bar which engages the frame at a third point when the barrel is placed in a locked position. The coin receptacle locking mechanism may further comprise a tray attached to the locking mechanism and having a notch that engages the frame when the tray is placed in a closed position.
A self draining locker shelf is also provided. The shelf includes a member having a sloping surface and a perimeter, a plurality of parallel ribs upstanding from the sloping surface and defining a channel between each pair of ribs and above the sloping surface, and a rim attached to the perimeter of the member, wherein said rim has at least one opening in fluid communication with each channel. In one embodiment, the shelf also includes at least one interlocking member formed on the rim for slidable engagement with at least one complimentary interlocking member of a frame.
In addition, a locker door is disclosed, wherein the locker door includes a front cover, a backing member, and top and bottom caps. The front cover includes opposed interlocking members and the backing member has second opposed interlocking members for engagement with the opposed interlocking members of the front cover, whereby the front cover and the backing member define a gap therebetween. The top cap includes at least one ridge, wherein the top cap ridge is fitted within the gap between said front cover and said backing member and the bottom cap has at least one ridge, wherein bottom cap ridge is fitted within the gap between the front cover and the backing member.
A lock for a locker is also disclosed. The lock comprises a support member having an outward facing surface and an inward facing surface opposite the outward facing surface, and a locking mechanism attached to the inward facing surface.
A method of manufacturing a locker is also provided. The method comprises cutting a first wall from a first material to a desired length, cutting a second wall from the first material to the desired length, cutting a third wall to the desired length, and slidingly engaging the first, second and third walls.
A method of limiting access to a locking mechanism on a locker is furthermore provided. The method includes positioning the locking mechanism adjacent an inward facing surface and fastening the locking mechanism to the locker.
Accordingly, the present invention provides solutions to the shortcomings of prior lockers. The present invention is suitable for outdoor use, is strong and simple to manufacture, and may be formed primarily of light weight plastic if desired. A feature of the locker of the present invention is that it prevents spilled material and other forms of impurities in the locker from contacting personal possessions later placed in the locker. Another feature of the locker of the present invention is that it may be easily cleaned by directing pressurized water from a hose or other device into the locker storage compartment. It is also a feature of the present invention that it provides a storage compartment that is configured such that liquids spilled or sprayed in the compartment will drain from the compartment. An additional feature of the present invention is that it includes a large coin receptacle and a locking mechanism that secures the coin receptacle on each of four sides. Those of ordinary skill in the art will readily appreciate, however, that these and other details, features and advantages will become further apparent in the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying Figures, there are shown present preferred embodiments of the invention wherein like reference numerals are employed to designate like parts and wherein:
FIG. 1 is a perspective view of a locker of the present invention;
FIG. 2 is an exploded perspective view of the locker of FIG. 1;
FIG. 3 is a front elevational view of the locker of FIGS. 1 and 2;
FIG. 4 is a right side elevational view of the locker of FIGS. 1-3;
FIG. 5 is a rear elevational view of the locker of FIGS. 1-3;
FIG. 6 is an enlarged top view of the locker of FIGS. 1 and 2;
FIG. 7 is an enlarged bottom view of the locker of FIGS. 1 and 2;
FIG. 8 is a top view of a locker frame of the present invention;
FIG. 9 is an enlarged top view of the left rear corner of the locker of FIGS. 1 and 2;
FIG. 10 is an enlarged top view of a portion of the locker of FIGS. 1 and 2 that includes a hinge channel;
FIG. 11 is an enlarged top view of a portion of the locker of FIGS. 1 and 2 that includes a lock channel:
FIG. 12 is a front view of the lock channel of the present invention;
FIG. 13 is an enlarged front view of the lower portion of the lock channel of FIG. 12;
FIG. 14 is a rear view of the lock channel of FIG. 12;
FIG. 15 is an enlarged rear view of the lower portion of the lock channel of FIG. 14;
FIG. 16 is an enlarged perspective view of the lower portion of the lock channel of FIGS. 12 and 14;
FIG. 17 is an enlarged left side view of the lower portion of the lock channel of FIGS. 12 and 14;
FIG. 18 is a perspective view of a lock channel reinforcement channel of the present invention;
FIG. 19 is a left side view of the lock channel reinforcement channel of FIG. 18;
FIG. 20 is a front view of the lock channel reinforcement channel of FIG. 18;
FIG. 21 is an end view of the lock channel reinforcement channel of FIG. 18;
FIG. 22 is a perspective view of a locking mechanism cover of the present invention;
FIG. 23 is a perspective view of a coin deflector of the present invention;
FIG. 24 is a perspective view of a shelf of the present invention;
FIG. 25 is a top view of the shelf of FIG. 24;
FIG. 26 is a bottom view of the shelf of FIG. 24;
FIG. 27 is a cross-sectional view of the shelf of FIGS. 24-26;
FIG. 28 is a perspective view of a shelf support of the present invention;
FIG. 29 is a front view of the shelf support of FIG. 28;
FIG. 30 is a side view of the shelf support of FIG. 28;
FIG. 31 is a perspective view of a top cap of the present invention;
FIG. 32 is an exploded assembly view of a door of the present invention;
FIG. 33 is a front view of the door of FIG. 32 shown in perspective;
FIG. 34 is a rear view of the door of FIG. 32 shown in perspective;
FIG. 35 is a rear elevation view of the door of FIG. 32;
FIG. 36 is a top plan view of a front cover of the door of FIGS. 32 and 33;
FIG. 37 is a top plan view of a rear member of the door of FIGS. 32, 34 and 35 ;
FIG. 38 is a perspective view of the bottom of an upper end cap of the door of FIG. 32;
FIG. 39 is a top view of the upper end cap of FIG. 38;
FIG. 40 is a bottom view of the upper end cap of FIG. 38;
FIG. 41 is a perspective view of the top of a lower end cap of the door of FIG. 32;
FIG. 42 is a bottom view of the lower end cap of FIG. 41;
FIG. 43 is a top view of the lower end cap of FIG. 41;
FIG. 44 is an exploded assembly view of a coin receptacle of the present invention;
FIG. 45 is a top view of the coin receptacle of FIG. 44 shown in perspective;
FIG. 46 is another top view of the coin receptacle of FIG. 44 shown in perspective;
FIG. 47 is a bottom view of the coin receptacle of FIG. 44 shown in perspective;
FIG. 48 is a top view of the coin receptacle of FIG. 44;
FIG. 49 is a side elevational view of the coin receptacle of FIG. 44;
FIG. 50 is a front elevational view of the coin receptacle of FIG. 44;
FIG. 51 is a top view of a face member of the coin receptacle of FIG. 44 and 46 - 50 ;
FIG. 52 is a front elevational view of the face member of FIG. 51;
FIG. 53 is a right side elevational view of the face member of FIG. 51; and
FIG. 54 is a perspective view of a locking cam of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is to be understood that the Figures and descriptions of the present invention included herein illustrate and describe elements that are of particular relevance to the present invention, while eliminating, for purposes of clarity, other elements found in a typical locker. Because the construction and implementation of such other elements are well known in the art, and because a discussion of them would not materially facilitate a better understanding of the present invention, discussion of those elements is not provided herein. It is also to be understood that the embodiments of the present invention that are described herein are illustrative only and are not exhaustive of the manners of embodying the present invention. For example, it will be recognized by those skilled in the art that the positions of the frame components including, for example, the hinge channel 40 and the lock channel 38 , may be reversed if an alternate embodiment is preferred.
Referring now to the drawings for the purpose of illustrating the present preferred embodiments of the invention only and not for the purpose of limiting the same, FIG. 1 is a perspective view of a locker 20 of the present invention having four storage compartments 22 and FIG. 2 is an exploded perspective view of the locker 20 of FIG. 1 . FIGS. 3-7 are a front, a right side, a back, a top and a bottom view, respectively, of the locker 20 of FIGS. 1 and 2. The locker 20 of FIGS. 1-7 includes a frame 24 , a door 26 , a locking mechanism 28 for locking the door 26 and a coin receptacle 30 . The frame 24 includes a rear panel 32 , a left side panel 34 , a right side panel 36 , a lock channel 38 , a hinge channel 40 and one or more shelves 42 . Each of those components may be fabricated from many materials including, for example, plastic, steel and stainless steel. The skilled artisan will appreciate that the material from which the locker components described herein are fabricated may be advantageously selected based on their compatibility with, for example, the ambient conditions in which the locker will be utilized and the method and/or solvents utilized in cleaning the locker 20 . For example, a locker 20 having a frame 24 fabricated of extruded plastic may advantageously be used in outdoor applications and may be cleaned by directing pressurized water on the frame 24 because an extruded plastic frame 24 is not prone to damage, such as rust, caused by precipitation or pressurized water. Furthermore, while the embodiment illustrated in FIGS. 1 and 2 includes four separately accessible compartments 22 , the invention may include any number of compartments 22 desired. Thus, the invention should not be limited to a four compartment 22 arrangement.
FIG. 4 illustrates a right side view of the locker 20 of FIGS. 1-3. The left side panel 34 and right side panel 36 may be cut to any desired length from the same side panel sheet (not shown). Use of a single panel sheet advantageously minimizes panel manufacturing costs by reducing the number of machines required to make the side panels and minimizing the variety of panels to be stored. The ability to simply cut the panels to any desired length also makes for simple manufacture of lockers of any height desired. The side panels 34 and 36 may be corrugated for strength and may include a plurality of L-locking tabs 44 running vertically along the inside surface 46 of the left side panel 34 and the inside surface 48 of the right side panel 36 . One or both of the side panels 34 and 36 may also include a finger joint 50 along the rear vertical edge 52 and a T-locking tab 54 on the front vertical edge of the side panels 34 and 36 . The rear panel 32 , which is illustrated in FIG. 5, may also have one or more L-locking tabs 44 that run vertically along the inside surface 58 of the rear panel 32 and finger joints 50 along the left vertical edge 60 of the rear panel 32 . FIG. 8 is a top view of the locker frame 24 without shelves 42 wherein the right side panel 36 , left side panel 34 and rear panel 32 are interconnected by way of finger joints 50 . FIG. 9 is an enlarged view of the left rear corner 64 of the locker 20 , showing the interconnected finger joints 50 of the left side panel 34 and the rear panel 32 . FIG. 9 also depicts a shelf 42 that is interlocked with the L-locking tabs 44 of the left side panel 34 and the rear panel 32 . The interconnection of the shelf 42 with the side panels 34 and 36 and rear panel 32 is discussed further hereinbelow. The finger joint 50 of the right side panel 36 may also be slidingly interlocked with the finger joint 50 of the right vertical edge 62 of the rear panel 32 . The use of finger joints 50 to connect the side and rear panels 34 , 36 and 32 is beneficial because the sliding connection simplifies manufacture. This is because the left rear frame corner 64 and right rear frame corner 66 formed by the interconnecting finger joints 50 are difficult to separate and because those corners 64 and 66 form rigid vertical supports.
FIG. 10 is an enlarged top view of a portion of the locker 20 that includes the hinge channel 40 of the locker frame 24 . The hinge channel 40 includes a U-shaped section 68 to which hinge components such as a torsion spring (not shown) for biasing the door 26 closed and any frontally positioned component may be attached. A T-locking channel 72 may be formed along the rear vertical edge 88 of the hinge channel 40 for receiving the T-locking tab 54 of the left side panel 34 . In that embodiment, the T-locking tab 54 slides into the T-locking channel 72 to interlock those components. Also in the embodiment illustrated, a reinforcement channel 76 is inserted into the hinge channel 40 . Thus components attached to the hinge channel 40 may be fastened through the reinforcement channel 76 to provide additional strength. The reinforcement channel 76 may be fabricated from aluminum or stainless steel so as to provide added strength for secure connection of frontally positioned components and to resist corrosion. The hinge channel 40 and reinforcement channel, therefore, beneficially provide a strong, continuous attachment area.
FIG. 11 is an enlarged top view of a portion of the locker 20 that includes the lock channel 38 . The lock channel 38 is sized to hold a standard locking mechanism 28 and to direct coins that have been inserted into the locking mechanism 28 to the coin receptacle 30 . In the embodiment illustrated in FIG. 11, the lock channel 38 is provided in two sections: a flat side section 78 , and a U-shaped section 80 into which a locking mechanism 28 is inserted. A shortcoming of many known lockers is that locking mechanisms 28 are typically inserted into a locker frame 24 from the front 82 of the locker 20 and attached through the front 82 of the locker 20 . When a locking mechanism 28 is so inserted, vandals have been known to disconnect the locking mechanism 28 and thereby gain access to the storage compartment 22 or coins held inside the lock channel 38 . The locking mechanism 28 of the present invention may be inserted into the lock channel 38 from the rear 86 of the channel and secured from the rear 86 , making removal of the locking mechanism 28 by prying or pulling through the front 82 of the locker 20 difficult. In the embodiment illustrated, the flat side section 78 has a T-locking channel 72 formed along a rear vertical edge 88 that slidingly accepts the T-locking tab 54 of the right side panel 36 . The front vertical edge 90 of the flat side section 78 of the lock channel 38 has a first bead channel 92 formed thereon, and a second bead channel 94 is located on an inner surface 96 of the flat side section 78 . Also in the embodiment illustrated, the U-shaped section 80 of the lock channel 38 has a first bead 98 formed along a front edge 100 and a second bead 102 formed along a rear edge 104 . The first bead 98 slidingly engages the first bead channel 92 and the second bead 102 slidingly engages the second bead channel 94 to form the lock channel 38 . FIG. 12 is a front view of the lock channel 38 having locking mechanisms 28 mounted therein and FIG. 13 is an enlarged front view of the lower portion of the lock channel 38 . FIG. 14 is a rear view of the lock channel 38 having locking mechanisms 28 mounted therein and FIG. 15 is an enlarged rear view of the lower portion of the lock channel 38 . In addition, FIG. 16 is an enlarged perspective view of the lower portion of the lock channel 38 and FIG. 17 is an enlarged left side view of the lower portion of the lock channel 38 . FIGS. 16 and 17 also illustrate a portion of the coin deflector 126 which is described hereinbelow.
FIGS. 18-21 illustrate the lock channel reinforcement channel 107 . FIG. 18 is a perspective view of the lock channel reinforcement channel 107 , FIG. 19 is a left side view of the lock channel reinforcement channel 107 , FIG. 20 is a front view of the lock channel reinforcement channel 107 and FIG. 21 is an end view of the lock channel reinforcement channel 107 . Like the hinge channel reinforcement channel 76 , the lock channel reinforcement channel 107 may be fabricated, for example, from aluminum or stainless steel so as to provide added strength for secure connection of frontally positioned components, to resist corrosion and to protect the locking mechanism 28 and the portion of the lock channel 38 through which coins are directed from access by vandals. The lock channel reinforcement channel 107 is sized to fit inside the lock channel 38 . The reinforcement channel 107 also includes an opening 108 along the front 110 and left side 112 of the reinforcement channel 107 through which a key barrel 114 and bolt 116 of the locking mechanism 28 may extend.
FIG. 22 is a perspective view of a locking mechanism cover 118 of the present invention. As illustrated in FIG. 11, the lock channel 38 may include a cover channel 120 in which the locking mechanism cover 118 may be secured. The locking mechanism cover 118 , in turn, may provide a structure for retaining a standard locking mechanism 28 in proper position. The locking mechanism cover 118 includes an outer surface 119 and an inner surface 121 and may include a fastener such as, for example the upper clamp 123 and lower clamp 125 illustrated in FIG. 22, to which the locking mechanism 28 may be fastened. The locking mechanism cover 118 may also include one or more cover deflectors 122 to deflect coins falling from above the cover to the open rear portion 124 of the lock channel 38 , through which the coins may pass in transit to the coin receptacle 30 .
FIG. 23 is a perspective view of a coin deflector 126 having a first angled side 127 and a second angled side 129 and which may be disposed at the lower portion 128 of the lock channel 38 to deflect coins toward the center 130 of the coin receptacle 30 . In conventional lockers, coins fall into a small receptacle located beneath the locking mechanism 28 . The present invention, however, beneficially provides for the lock channel 38 to be cut away so that coins may be stored in a much larger receptacle 30 . Therefore, the coin deflector 126 is useful in that it deflects falling coins toward the center 130 of the coin receptacle 30 , thereby avoiding build-up and overflow of coins in the coin receptacle 30 . The coin receptacle 30 is discussed in more detail hereinbelow.
FIG. 24 is a perspective view of the shelf 42 of the present invention. FIG. 25 is a top view and FIG. 26 is a bottom view of the shelf 42 of FIG. 24 . One or more shelves may be inserted into the frame 24 to separate compartments 22 . Shelves may also be utilized as an upper cover 132 , as a base 134 and as a separator 136 to be placed above the coin receptacle 30 as shown in FIG. 2 . In the embodiment illustrated, each shelf 42 includes a member 138 and an endless upright rim 140 attached to the perimeter 142 of the member 138 . The rim 140 furthermore includes a plurality of L-locking channels 144 , each of which is sized to accept one of the L-locking tabs 44 of the side and back panels 34 , 36 and 32 . By interlocking the frame 24 with the shelves, additional structural rigidity is provided to the frame 24 of the present locker 20 . The vertical location of each shelf 42 within the locker 20 is infinitely adjustable because the L-locking channels 144 of each shelf 42 will slide along the L-locking tabs 44 to any desired location. Known mechanisms for fastening may be utilized to attach the shelf 42 to the frame 24 in the desired location. For example, holes 146 may be punched in the side and back panels 34 , 36 and 32 and aligned with pre-punched holes 148 in each shelf 42 and rivets 150 may be placed through the aligned holes 146 and 148 to secure the shelf 42 in the desired location.
FIG. 27 is a cross-sectional view that illustrates the sloped member 138 and upstanding ribs 152 of the shelf 42 of FIGS. 24-26. Conventional lockers are susceptible to becoming soiled through, for example, spills within the locker 20 and placement of sticky materials on the locker shelves 42 . The shelves 42 of the present invention are beneficially configured to discharge spilled liquids from the locker compartments 22 and provide an upper surface 137 on which items may be placed to avoid contact with soil on a lower surface 139 of the shelf 42 . The member 138 of each shelf 42 slopes toward the front 160 of the shelf 42 . A plurality of upstanding ribs 152 extend up from the sloping lower surface 139 of the member 138 to define the upper surface 137 along a plane defined by the upper edges 153 of the ribs 152 . The upper edge 153 of each rib 152 is substantially horizontal such that sloping channels 154 are defined between the horizontal ribs 152 . Drain openings 156 are also provided through the rim 140 along the member 138 in the embodiment illustrated, such that liquids that enter the channels 154 will drain through the openings 156 and thereby exit the locker 20 . Those liquids could enter the channel by, for example, spills occurring within the locker 20 or by directing pressurized water into the storage compartments 22 to clean the locker 20 . It has furthermore been discovered through experimentation that a member 138 sloped at an approximately 1° angle is sufficient to cause liquids in the channels 154 to drain from the member 138 . The sloping member 138 and parallel rib 152 configuration is therefore beneficial in that it provides for easy cleaning, particularly in outdoor installations. For example, the present locker 20 may be cleaned simply by directing pressurized water into each storage compartment 22 . In that way, any soil in the storage compartment 22 is removed by the pressurized water and carried into the channels 154 from which the water and soil will flow through the openings 156 , thereby exiting the locker 20 . The sloping member 138 and parallel rib 152 configuration is also beneficial in protecting personal belongings from soil that exists on the member 138 by providing the upper surface 137 on which personal items may be placed so as not to contact any soil in the channels 154 .
FIGS. 28-30 illustrate a shelf support 158 for supporting the front 160 of the shelf 42 . At least one shelf support 158 may be fastened to the lock channel 38 and/or the hinge channel 40 by, for example, placing a rivet 150 through the shelf support 158 , the rim 140 of the shelf 42 and the lock channel 38 at a point below the shelf 42 such that the rivet 150 is inaccessible through the storage compartment 22 . The shelf support 158 may also operate to prevent removal of the shelf 42 by lifting. In the embodiment illustrated in FIGS. 28-30, the shelf support 158 includes a bent portion 161 . The bent portion 161 extends through a slot 162 in the shelf 42 and above the shelf 42 , thereby preventing the front 160 of the shelf 42 from being lifted.
FIG. 31 is a perspective view of a top cap 164 of the present invention. Where a shelf 42 of the present invention is used as an upper cover 132 for the locker 20 , a top cap 164 may be attached over the front of the upper cover 132 to cover the lock channel 38 and the hinge channel 40 as shown in FIG. 6 . The top cap 164 may also extend even with the door 26 to prevent access to the rear of the door 26 , thereby restricting the ability of a vandal to pry the door 26 open, and to give the locker 20 a finished appearance.
FIGS. 32-43 illustrate the door 26 of the locker 20 . FIG. 32 is an exploded assembly view of the door 26 shown in perspective. The door 26 includes a front cover 166 , a backing member 168 , an upper end cap 170 and a lower end cap 172 that is structurally identical to the upper end cap 170 . The front cover 166 and backing member 168 may be cut to any desired height so as to flexibly meet a variety of locker size needs. As previously discussed, the left side panel 34 , right side panel 36 and rear panel 32 may also be cut to any desired length and the shelves 42 may be place vertically anywhere along the frame 24 . Therefore, lockers 20 of the present invention can be built to any desired height with any number of storage compartments 22 of any desired size. The flexibility inherent in such a locker 20 is beneficial in that lockers 20 may be easily manufactured to meet many different needs through the use of common components of the present invention. FIG. 36 is a top view of the front cover 166 and FIG. 37 is a top view of the backing member 168 . As may be seen in FIG. 36, the front cover 166 of the door 26 includes an inward turned edge 174 and an opposing T-locking tab 176 . The T-locking tab 176 extends from the rear surface 178 of the front cover 166 along the right side 180 of the cover 166 with the tab facing left. The inward turned edge 174 is directed from the left side of the cover 166 toward the T-locking tab 176 . As may be seen in FIG. 37, the backing member 168 includes a slot 182 into which the inward turned edge 174 of the front cover 166 extends and a T-locking channel 184 that interlocks with the T-locking tab 176 of the front cover 166 .
FIG. 38 is a bottom view shown in perspective of the upper end cap 170 of the door 26 of the present invention, and FIGS. 39 and 40 are top and bottom views of the upper end cap 170 , respectively. The lower end cap 172 is formed as a mirror image of the upper end cap 170 . FIG. 41 is a bottom view shown in perspective of the lower end cap 172 and FIGS. 42 and 43 are top and bottom views of the lower end cap 172 , respectively. The assembly of the upper and lower end caps 170 and 172 to the front cover 166 and backing member 168 are also illustrated in FIGS. 32-34. The end caps 170 and 172 secure the front cover 166 to the backing member 168 and provide the door 26 with finished upper and lower surfaces 171 and 173 , respectively. As depicted on FIG. 32, a first ridge 186 (shown on FIG. 38) of the upper end cap 170 fits within the gap 188 formed between the front cover 166 and backing member 168 . A second ridge 190 also extends from the upper end cap 170 . The second ridge 190 extends along the rear surface 192 of the backing member 168 when engaged therewith. Once the front cover 166 and backing member 168 have been cut to a desired length, the first ridge 186 of the upper end cap 170 is inserted into the upper end 187 of the gap 188 formed between the front cover 166 and backing member 168 with the second ridge 190 of the upper end cap 170 disposed along the rear surface 192 of the backing member 168 . The upper end cap 170 is fastened to the front cover 166 and backing member 168 by any known means including placing screws (not shown) through the upper end cap 170 into the front cover 166 and/or backing member 168 . Similarly, the first ridge 194 of the lower end cap 172 is inserted into the lower end 189 of the gap 188 formed between the front cover 166 and backing member 168 . The second ridge 196 of the lower end cap 172 is disposed along the rear surface 192 of the backing member 168 and the lower end cap 172 is fastened to the front cover 166 and backing member 168 . The doors of conventional lockers are susceptible to being damaged by vandals or otherwise. Therefore, it is a benefit of the present invention that the front cover 166 can be easily replaced without necessitating replacement of the entire door 26 .
The door 26 is attached to a commonly known hinge rod 70 which may be fabricated from, for example, aluminum or stainless steel. Where a locker 20 is to include multiple doors 26 stacked one above another with shelves separating each compartment 22 , a single hinge rod 70 may extend through the assembly such that each door 26 swings on the common hinge rod 70 . The hinge rod 70 may also extend through the shelves of the locker 20 , thereby securing the doors 26 to the frame 24 . It is also beneficial to utilize a torsion spring (not shown) in conjunction with each door 26 . The torsion spring beneficially biases the door 26 toward its closed position so that all doors 26 are closed unless held open by a user.
FIGS. 44-54 depict the coin receptacle 30 which, in the embodiment illustrated, also pivots on the common hinge rod 70 which is illustrated in FIG. 2 . The coin receptacle 30 includes a face member 200 , a three-point coin tray lock 202 , and a fixed tray 204 . FIG. 44 is an exploded assembly view of the face member 200 and the fixed tray 204 . The face member 200 and fixed tray 204 may be fabricated from the same material as the frame 24 and may be, for example, plastic. The face member 200 may be attached to the fixed tray 204 by a known method including, for example, riveting the face member 200 and fixed tray 204 together. The face member 200 includes an upper ear 206 and a lower ear 208 through which the hinge rod 70 is disposed and the face member 200 may extend across the entire width of the locker 20 . The face member 200 may furthermore include a hole 210 through which the barrel 216 of the coin tray lock 202 may extend. The fixed tray 204 may include a coin holding compartment 212 , a locking mechanism compartment 214 , and a hinge rod receptacle 215 that fits between the upper ear 206 and lower ear 208 of the face member 200 . As may be seen in FIGS. 16 and 17, a portion of the lock channel 38 may be cut away to permit the fixed tray 204 to extend under the lock channel 38 to accommodate the passage of coins passing from the storage compartment locking mechanism 28 to the coin holding compartment 212 . By extending the coin receptacle 30 thus, the coins simply drop into the receptacle 30 after passing through the storage compartment locking mechanism 28 . The right side 213 of the coin receptacle 30 is arcuate to permit the fixed tray 204 to rotate on the hinge rod 70 without contacting the right side panel 36 of the locker 20 . A removable tray (not shown) may be placed in the fixed tray 204 of the coin receptacle 30 . Use of the removable tray will simplify removal of coins from the fixed tray 204 by utilizing a method of coin removal comprising removing the removable tray, pouring the contents into a collection bin (not shown) and reinserting the removable tray in the fixed tray 204 .
In the embodiment illustrated in FIG. 44, the three-point coin tray lock 202 is inserted into the lock compartment of the fixed tray 204 . The three-point coin tray lock 202 includes a barrel 216 that extends through the face member, a cam 218 and a lock bar 220 . The barrel 216 accepts a key (not shown) which locks and unlocks the three-point coin tray locking mechanism 202 when rotated. The locking cam 218 has an upper lobe 222 , a lower lobe 224 and a lock bar connecting lobe 226 . The locking cam 218 is attached to the barrel 216 of the lock through a centrally located opening 228 in the cam 218 such that the lobe rotates when the barrel 216 is rotated by the key. When the locking cam 218 is rotated to its locked position, the upper lobe 222 extends into a slot 230 defined in the bottom 232 of the shelf 42 that is placed above the coin receptacle 30 and the lower lobe 224 extends into a slot 234 defined in the top 236 of the shelf 42 that is placed below the coin receptacle 30 . See FIGS. 25 and 26 to view the slots 230 and 234 in the bottom 232 and top 236 of the shelf 42 , respectively. The lock bar 220 is pivotally attached to the lock bar connecting lobe 226 such that the lock bar 220 extends into the frame 24 or an opening 238 in a member such as, for example, the deflector 126 as depicted in FIGS. 16 and 17 when the locking cam 218 is rotated to its locked position. The lock bar 220 may furthermore have a hooked end 240 that will extend along the deflector 126 when placed in the locked position to further secure the lock bar 220 therein. The fixed tray 204 may also include a notch 242 as illustrated in FIG. 48 that engages the frame 24 when the coin receptacle 30 is closed, thereby further securing the coin receptacle 30 when the coin receptacle 30 is closed and locked.
A method is also provided for protecting goods placed on a surface from liquid that is deposited on the surface. The method includes draining the liquid from the surface by providing sloped channels 154 in the surface, and placing the goods on upstanding ribs 152 disposed between the channels 154 .
Thus, from the foregoing discussion, it is apparent that the present locker 20 solves many of the problems encountered by prior lockers.
Those of ordinary skill in the art will, of course, appreciate that various changes in the details, materials and arrangement of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by the skilled artisan within the principle and scope of the invention as expressed in the appended claims. | A locker. The locker comprises a first side wall having an interlocking portion, a second side wall having a first interlocking portion engaging the interlocking portion of the first side wall and a second interlocking portion, and a third side wall having an interlocking portion engaging the second interlocking portion of the second side wall. A coin receptacle, coin receptacle locking mechanism, a shelf and a door for the locker are also disclosed. A method of manufacturing a locker is also provided. The method comprises cutting a first wall from a first material to a desired length, cutting a second wall from the first material to the desired length, cutting a third wall to the desired length, and slidingly engaging the first, second and third walls. A method for limiting access to a locking mechanism is also provided, which comprises positioning the locking mechanism adjacent an inward facing surface and fastening the locking mechanism to the locker. | 4 |
FIELD OF THE INVENTION
This invention relates to a steering column locking device. More specifically, this invention relates to a steering column locking device for golf carts, and the like.
BACKGROUND OF THE INVENTION
Steering column locking devices are used to prevent vehicle theft. While many such devices have been created for automobiles, relatively few theft protection devices for golf carts exist. One such example of a golf cart anti-theft device is described in U.S. Pat. No. 5,460,021 and is hereby incorporated by reference. Multiple examples of steering column lock devices for automobiles are described in U.S. Pat. No. 7,234,328 B2, U.S. Pat. No. 7,364,198 B2, and U.S. Pat. No. 7,316,138 B2, which are hereby incorporated by reference.
Unless securely locked inside a building, golf carts remain substantially unprotected against theft. Further, steering column locking devices for automobiles cannot simply be transferred to a golf cart. Differences in the size and shape of the respective vehicles' steering columns create just one of the difficulties presented in attempting to use an automobile steering column locking device on a golf cart.
Accordingly, there remains a need for a steering column locking device that may be used on golf carts to effectively prevent theft.
SUMMARY OF THE INVENTION
The embodiments of the invention and the method described herein address the shortcomings of the prior art.
In general terms, the invention may be described as including the following:
A steering column comprising: (a) a sleeve portion having an open bore or space extending the length of said sleeve portion; (b) a steering shaft portion disposed within the sleeve portion, and adapted to rotate within said sleeve portion, and having at least one terminal end portion extending beyond the sleeve portion; (c) a main body portion fixed about the sleeve portion having (i) a central aperture extending through the main body adapted to receive the sleeve portion; (ii) a groove about the central aperture extending partially through the main body; (iii) a locking aperture extending through the main body and extending into the groove; (iv) a locking mechanism extending through the locking aperture so as to allow all or some portion of the locking mechanism to extend through the groove, which locking mechanism is adapted to be reversibly removed; (d) a second body portion having (i) a perimeter wall, (ii) a bottom end, and (iii) a top end; (iv) at least one side opening extending partially or completely through the perimeter wall and positioned so as to allow the locking mechanism of the main body portion to extend into the at least one side opening; the bottom end having a portion extending into the groove of the main body portion, the bottom end being adapted to rotate with respect to the main body portion between an unlocked position wherein the locking aperture and the at least one side opening are not aligned and a locked position wherein the locking aperture and the at least one side opening are aligned; and the top end having an opening.
The sleeve portion may be any material such as a metal or a high strength plastic of sufficient strength for use in a security device of the type of the present invention. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. The sleeve portion may be cylindrical in shape or alternatively may have multiple faces. Similarly, the steering shaft may be any material such as a metal or a high strength plastic. A number of different types of materials may also be used for making the steering shaft of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. The shaft may be cylindrical in shape or alternatively may have multiple faces.
In addition, the main body portion may be any stable material such as a metal or a high strength plastic. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. It may be fixed about the sleeve portion by means which may include, but are not limited to, an adhesive, soldering, shim piece, or through the use of a fastener, such as a screw, preferably one that is designed for relatively secure attachment, such as one-way or counter-sunk screw, that are relatively difficult to remove.
The central aperture extending through the main body may be any shape to receive the sleeve portion, preferably such that the two pieces fit snugly and securely together, in accordance with the security function of the invention.
The groove about the central aperture may be circular, so as to allow rotational movement of the bottom end portion of the second body portion within the groove. Preferably, the groove should not extend through the main body portion such as would compromise the security function of the system of the present invention. However, there may be one or more optional openings in the groove, such that water and other materials that may enter the groove, and escape through the openings.
The locking aperture extends through the main body and into the groove. The aperture may also extend through the groove. The aperture may be any shape so as to receive the locking mechanism.
The locking mechanism may shaped so as to fit into the locking aperture and may be secured within the locking aperture by adhesion, soldering, use of an interferant member, such as a pin, or other means appropriate to the security function of the device. It may be secured within the locking aperture by a pin inserted into the main body, extending through the locking aperture and through a groove on the locking mechanism. The locking mechanism operates so as to extend through the locking aperture and into the groove, thus engaging the lock. The mechanism may have a safety feature, which allows the mechanism to lock in its engaged position, so as to require an additional action to remove the locking mechanism from the groove, thereby disengaging or unlocking the device.
The second body portion may be any material such as a metal or a high strength plastic. A number of different types of materials may be used for making the second body portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
The second body portion may have at least one side opening extending partially or completely through the perimeter wall. The opening may be any shape such as to receive the locking member or mechanism when engaged and inhibit rotation of the bottom portion within the groove. The opening may be an aperture or may be an opening extending the length of the perimeter wall, or any combination thereof that will inhibit the rotational movement of the second body portion within the groove, when the locking mechanism is engaged.
The portion of the bottom end extending into the groove of the main body portion is circular in shape so as to allow it to rotate within the groove.
The present invention also includes an embodiment in which the opening in the top of the second body portion is shaped to receive the terminal end portion of the steering shaft portion and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the steering shaft portion. For example, the top may be triangular in shape or rectangular in shape. Accordingly, the terminal end portion will be a corresponding shape so as to fit into the top of the second body portion and cause the second body portion to rotate with the steering shaft portion.
In another embodiment, the terminal end portion of the steering shaft has one or more splines and the opening of the top end of the second body portion is shaped so as to receive the splined terminal end portion so as to cause the second body portion to rotate along with the rotation of the steering shaft portion. In other words, the engagement between the opening of the top end of the second body portion and the splined terminal end portion integrally rotates the second body portion with respect to the steering shaft.
The present invention also includes an embodiment wherein the top end of the second body portion comprises a removable portion that includes the opening of the top end. The removable portion and the portion of the second body portion from which the removable portion is removed may be threaded. Alternatively, the removable portion may be fixed in the second body portion by means which may include, but not limited to, adhesion or soldering.
In another embodiment, the central aperture is defined by at least one removable portion wherein the main body portion is shaped so as to hold removable portion(s) within the main body portion.
In yet another embodiment, the severable main body portion comprises a first portion and a second portion wherein the first portion is fixed to the second portion. The first and second portions may be fixed to one another by means including, but not limited to, one or more set screws, adhesion or soldering.
In another embodiment of the present invention, the terminal end portion of the steering shaft has one or more splines and second body portion is fixed to an adaptor having an aperture shaped so as to receive the splined terminal end portion so as to cause said second body portion to rotate along with the rotation of said steering shaft portion. In other words, the engagement between the aperture and the splined terminal end portion integrally rotates the second body portion with respect to the aperture.
The present invention also includes a locking system comprising: (a) a severable main body portion having (i) a central aperture extending through the main body; (ii) a groove about the central aperture extending partially through the main body; (iii) a locking aperture extending through the main body and extending into the groove; (iv) a locking mechanism extending through the locking aperture so as to allow all or some portion of the locking mechanism to extend through the groove, with such locking mechanism adapted to be reversibly removed; (b) a second body portion having (i) a perimeter wall, (ii) a bottom end, and (iii) a top end; (iv) at least one side opening extending partially or completely through the perimeter wall and positioned so as to allow the locking mechanism of the main body portion to extend into the at least one side opening; the bottom end having a portion extending into the groove of the main body portion, the bottom end being adapted to rotate with respect to the main body portion between an unlocked position wherein the locking aperture and the at least one side opening are not aligned and a locked position wherein the locking aperture and the at least one side opening are aligned; and the top end having an opening.
The severable main body portion may be any material such as a metal or a high strength plastic suitable to the security function of the device. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
The central aperture extending through the main body may be any shape to receive the sleeve portion. Further, the groove about the central aperture may be circular, so as to allow rotational movement of the bottom end portion of the second body portion within the groove. The groove normally should not extend through the main body portion; although, there may be one or more openings in the groove, such that water and other materials that may enter the groove, and escape through the openings.
The locking aperture extends through the main body and into the groove. The aperture may also extend through to the interior side of the groove. The aperture may be any shape so as to receive the locking mechanism.
The locking mechanism may shaped so as to fit into the locking aperture and may be secured within the locking aperture by adhesion, soldering, use of an interferant member, such as a pin, or other means appropriate to the security function of the device. It may be secured within the locking aperture by a pin inserted into the main body, extending through the locking aperture and through a groove on the locking mechanism. The locking mechanism operates so as to extend through the locking aperture and into the groove, thus engaging the lock. The mechanism may have a safety feature, which allows the mechanism to [lock] in its engaged position, so as to require an additional action to remove the locking mechanism from the groove, thereby un-engaging or unlocking the device.
The second body portion may be any stable material such as a metal or a high strength plastic. A number of different types of materials may be used for making the second body portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
The second body portion may have at least one side opening extending partially or completely through the perimeter wall. The opening may be any shape such as to receive the locking mechanism when engaged and inhibit rotation of the bottom portion within the groove. The opening may be an aperture or may be an opening extending the length of the perimeter wall, or any [combination] thereof that will inhibit the rotational movement of the second body portion within the groove, when the locking mechanism is engaged.
The portion of the bottom end extending into the groove of the main body portion is circular in shape so as to allow it to rotate within the groove.
The locking system may also be such that the opening of the top end is shaped to receive a terminal end portion of a rotatable steering shaft and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the terminal end portion.
The present invention also includes an embodiment in which the opening of the top end of the second body portion is shaped to receive a terminal end portion of a rotatable steering shaft and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the terminal end portion. For example, the top may be triangular in shape or rectangular in shape. Accordingly, the terminal end portion will be a corresponding shape so as to fit into the top of the second body portion and the engagement between the two causes the second body portion to rotate with the terminal end portion.
The present invention also includes an embodiment wherein the terminal bore is shaped so as to receive a splined terminal end portion of a rotatable column so as to cause the second body portion to rotate along with the rotation of the terminal end portion. In other words, the engagement between the terminal bore and the splined terminal end portion integrally rotates the second body portion along with the rotation of the column.
The present invention also includes an embodiment wherein the top end of the second body portion comprises a removable portion that includes the opening of the top end. The removable portion and the portion of the second body portion from which the removable portion is removed may be threaded. Alternatively, the removable portion may be fixed in the second body portion by means which may include, but are not limited to, adhesion or soldering.
In another embodiment, the central aperture is defined by at least one removable portion wherein the main body portion is shaped so as to hold the at least one removable portion within the main body portion.
In yet another embodiment, the severable main body portion comprises a first portion and a second portion wherein the first portion is fixed to the second portion. The first portion may be fixed to the second portion by means which may include, but are not limited to, an adhesive, soldering, shim piece, or through the use of a fastener, such as a screw, preferably one that is designed for relatively secure attachment, such as one-way or counter-sunk screw, that are relatively difficult to remove.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the steering column locking device on a golf cart, in accordance with one embodiment of the present invention.
FIG. 2 is a side view of the steering column locking device, in accordance with one embodiment of the present invention.
FIG. 2A is a detailed side view of the steering column locking device, in accordance with one embodiment of the present invention.
FIG. 3 is an perspective view of the steering column locking device.
FIG. 4 is an upper side exploded perspective view of the steering column locking device, in accordance with one embodiment of the present invention.
FIG. 5 is an exploded perspective exploded view of the main body portion and locking mechanism in accordance with one embodiment of the present invention.
FIG. 6 is a side perspective view of the steering shaft and at least one removable portion in accordance with one embodiment of the present invention.
FIG. 7 is a bottom side perspective view of the second main body portion in accordance with one embodiment of the present invention.
FIG. 8 is a cross sectional view of one embodiment of the present invention.
FIG. 9 is a cross sectional view of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the foregoing summary, the following describes a preferred embodiment of the present invention which is considered to be the best mode thereof. With reference to the drawings, the invention will now be described in detail with regard for the best mode and preferred embodiment.
FIG. 1 shows steering column 1 on a golf cart.
FIG. 2 shows steering column 1 showing the position of main body portion 3 of a locking mechanism of the present invention.
FIG. 2A shows a larger view of steering column 1 having a steering shaft portion 2 and main body portion 3 fixed about steering shaft portion 2 . In the preferred embodiment, the main body portion will be fixed about the steering shaft portion by screws (not shown, but residing in counter sink aperture 4 ). The main body portion may be any stable material such as a metal or a high strength plastic. Preferably, the main body portion is 6061-T6 aluminum, machined into the desired shape. However, the present invention could also be constructed of a plastic that can be molded or machined into the desired shape.
FIG. 2A further shows main body portion 3 having portions 3 a and 3 b . In the preferred embodiment, main body portion 3 is machined into its desired shape, then divided into portions 3 a and 3 b by a machine. Preferably, portions 3 a and 3 b and fixed about steering shaft 2 and fixed to one another by screws (not shown, but residing in counter sink aperture 4 ). In the preferred embodiment, portions 3 a and 3 b are fixed to one another by tamper proof screws.
FIG. 3 is an upper plan view of the present invention, showing steering column 1 having a steering shaft portion 2 and main body portion 3 , having portions 3 a and 3 b , fixed about steering shaft portion 2 . FIG. 3 also shows counter sink aperture 4 .
FIG. 3 further shows locking mechanism 5 inserted into locking aperture 6 . Finally, FIG. 3 shows locking pin 7 . In the preferred embodiment, locking pin 7 is inserted into the main body portion 3 , and passes through a groove on the outside of locking mechanism 5 , thereby restricting movement of locking mechanism 5 with respect to the locking aperture 6 , and preventing removal of the locking mechanism.
FIG. 4 is an exploded view of the present invention and shows steering column 1 , steering shaft portion 2 , and main body portion 3 having a central aperture 8 , defined when main body portions 3 a and 3 b are fixed to one another. FIG. 4 shows tamper proof screws 4 a and 4 b , which, in the preferred embodiment, are threaded so as to engage with correspondingly threaded counter sink aperture 4 . FIG. 4 also shows locking mechanism 5 , locking aperture 6 , and locking pin 7
FIG. 4 also shows second body portion 9 having perimeter wall 9 a , at least one side opening 9 b , bottom end portion 9 c , and top end opening 9 d.
In the preferred embodiment, the present invention has shim pieces 10 , as shown in FIG. 4 . Shim pieces 10 are placed inside central aperture of the main body portion, and provide a closer fit with the steering shaft. Preferably, the shim pieces are also made of machined aluminum, however, other materials such as metal or a high strength plastic may also be used. In the preferred embodiment, the central aperture will have a bottom lip, with the bottom lip having a slightly smaller diameter, such that shim pieces may fit inside the aperture without sliding through the aperture. The resulting diameter of the shim pieces will preferably have a diameter that corresponds to the out diameter of the steering shaft about which the main body portion is fixed
FIG. 5 shows main body portion 3 having a central aperture 8 . Preferably, the central aperture is machined out of the main body portion prior to the division of the main body portion into two portions. The aperture typically will have a diameter that corresponds to the outer diameter of the steering shaft about which it is fixed.
FIG. 5 also shows main body 3 portion having a groove 11 . The groove 11 has a width 11 a that is preferably large enough to accommodate the bottom end portion of the second body potion. Typically, the groove may be machined out of the main body portion. Further, in the preferred embodiment, the groove should not extend through the main body portion, as that would sever the main body portion. Instead, it should only extend into the main body portion, but not through. Additionally, in the preferred embodiment, there may be one or more openings in the groove, such that water and other materials that may enter the groove can escape through the openings.
FIG. 5 also shows locking aperture 6 and locking mechanism 5 . In the preferred embodiment, the locking aperture opening is circular and the locking mechanism is cylindrical, with a circumference that corresponds to the locking aperture. In the preferred embodiment, the locking mechanism has a cylinder 5 b which may extend and retract by the insertion and rotation of a key 5 a into locking mechanism 5 .
FIG. 5 also shows a locking pin 7 that is inserted into pin hole 7 a . The locking pin passes through a groove in the locking mechanism, inserted into locking aperture, and inhibits the removal of the locking mechanism from the locking aperture. The pin may be inserted into the pin hole such that the top of the pin is flush with the main body portion, thus inhibiting easy removal of the locking mechanism.
FIG. 6 shows steering shaft 2 having a splined section 2 a and a threaded section 2 b . In the preferred embodiment, splined section 2 a inserts into an aperture with corresponding splines, thus causing steering shaft 2 to rotate with the steering wheel. A nut threads onto threaded section 2 b to prevent the steering wheel from lifting off the splined section.
FIG. 6 also shows shim pieces 10 a and 10 b . The approximate circumference of the arcuate shim pieces corresponds to the shaft circumference. In the preferred embodiment, the shim pieces are held to the shaft by pressure from the main body portion.
FIG. 7 shows second body portion 9 attached to and steering wheel 12 . Second body portion 9 has side openings 9 b 9 ba 9 bb and 9 bc . In the preferred embodiment, the side openings are slightly larger than the locking pin, so as to allow the locking pin to insert into the opening and thus inhibit the rotation of the steering shaft. In other embodiments, the openings may be larger, although that will allow greater rotational movement of the steering shaft when the locking mechanism is engaged. In addition, the openings may be larger longitudinally, which would allow leeway in mounting of the main body portion.
FIG. 8 shows a cross section view of the steering column 1 . FIG. 8 shows locking mechanism 5 in the unlocked, unengaged position, as locking pin 5 b is shown withdrawn from side opening 9 b of the second body portion 9 . Thus the second body portion is free to rotate within groove 11 of main body portion 3 .
FIG. 8 also shows a third body portion 13 having a shaft opening 13 a . FIG. 8 shows steering shaft 2 inserted through the top aperture 9 d of the second body portion, into shaft opening 13 a of the third body portion 13 , where the splined portion 2 a of steering shaft 2 is inserted into corresponding splined shaft opening 13 a of third body portion 13 .
FIG. 9 shows a cross section view of steering column 1 , but with locking mechanism 5 in the engaging. In the preferred embodiment, the locking mechanism operates to insert the locking rod into an opening in the second body portion, as a key is turned. The locking rod is reversibly removed when the key is turned in the opposite direction. In the preferred embodiment, the locking rod passes through the side opening of the second body portion, inhibiting rotational movement of the steering shaft. In another embodiment, the locking rod may enter the second body portion, but not pass all the way through. It is also possible for the locking rod to pass through the second body portion, through an opening on the main body portion and touch the steering shaft. | A steering column locking device. More specifically, a steering column locking device for golf carts, and the like. | 8 |
CROSS REFERENCE TO RELATED PATENT APPLICATION
[0001] This patent application claims priority of U.S. Provisional Patent Application No. 60/546,451, entitled “API Test Tool,” filed Feb. 19, 2004, which is incorporated herein by reference in its entirety. This patent application is related to co-pending U.S. patent application Ser. No. ______ (Atty. Docket No. ORACP022/OID-2004-013-01) and U.S. patent application Ser. No. ______ (Atty. Docket No. ORACP023/OID-2004-014-01), filed concurrently herewith, which are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to database systems. More specifically, the invention relates to an application programming interface (API) testing system which enables API frameworks and application code to be efficiently tested.
[0004] 2. Description of the Related Art
[0005] An application programming interface (API) is the interface used, or the set of calling conventions used, to allow an application program to access an operating system, as well as other system resources. APIs are often defined at a source code level, and effectively enable a level of abstraction to be present between an application program and a kernel. In some instances, an API may provide an interface between a high level language and lower level services, particularly those services or utilities which may have been written without taking into account calling conventions of compiled languages.
[0006] Testing of framework and application code associated with APIs is important to ensure that APIs function as intended. Without thorough testing of the framework and the application code associated with APIs, any errors or other unexpected results which may occur when an API is put into use may not be discovered until the API is used. When an API that is in use fails to function as intended, an application program which uses the API may be prevented from operating as desired.
[0007] Typically, for each test case associated with an API, a specific API test is coded and developed. The requirements for valid API tests on a framework and application code may be prohibitive in that a generally high number of tests are typically needed, and many issues may arise relating to the management of the tests. Hence, the requirements for comprehensive API tests on a framework and application code are often considered to be too extensive for comprehensive tests to be productive. As a result, API tests are likely to only be written to test code or test cases which are considered to be particularly important or critical. In other words, not all APIs may be thoroughly tested.
[0008] When only some test cases associated with an API are subjected to API testing, the reliability of the API may be compromised, as the framework and application code associated with the API is not fully tested. Since the overhead and the overall costs associated with comprehensively testing the framework and application code associated with the API is generally prohibitive, many developers and users are electing to write API tests for only the most crucial test code or test cases.
[0009] Therefore, what is needed is a method and an apparatus which enables the framework and application code associated with an API to be efficiently tested. That is, what is desired is an API test tool which provides a framework which allows API tests to be readily developed.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a system for enabling the framework and the application code associated with an application programming interface (API) to be efficiently and comprehensively tested. According to one aspect of the present invention, a structure that defines an API test in declarative metadata includes an entity to be tested, a first metadata arrangement, and a second metadata arrangement. The first metadata arrangement includes any data to be used when the entity is tested, and the second metadata arrangement includes any expected outputs associated with testing the entity. In one embodiment, the declarative metadata structure is represented as XML.
[0011] The specification of API tests in declarative metadata allows the API tests to be run within a framework which enables testing to occur without requiring that new, specific API tests be written for each test case. The use of declarative metadata such as XML metadata enables testing of an API framework and API application code to occur using sets of tags which are predefined, i.e., functionality associated with different API tests may be reused. Hence, API tests may be efficiently developed and run, and an API may be comprehensively tested in an efficient manner.
[0012] According to another aspect of the present invention, a structure that is arranged to define an API test suite in declarative metadata includes a first entity to be tested and a second entity to be tested. The first entity has associated first metadata arrangement including any inputs associated with testing the first entity and an associated second metadata arrangement including any expected outputs associated with testing the first entity. The second entity has an associated third metadata arrangement including any inputs associated with testing the second entity and an associated fourth metadata arrangement including any expected outputs associated with testing the second entity.
[0013] In one embodiment, the output associated with the first entity is stored in an in-memory data structure. In such an embodiment, the output that is stored in the in-memory data structure may be used as an input associated with the second entity.
[0014] According to still another aspect of the present invention, a method for testing at least a first entity using a framework which includes a execution engine, a test interface, and an adapter that is in communication with the test interface includes obtaining a test application that is specified in declarative metadata and specifies at least the first entity being tested. The method also includes accessing the adapter through the test interface, the adapter being arranged to cooperate with the test interface to execute the test application, and running the test application using the test interface and the adapter. In one embodiment, the first entity is an API method invocation. In another embodiment, the test application is a SQL test application.
[0015] In accordance with yet another aspect of the present invention, a method for executing a test application includes executing a first API test that produces a first output, and storing the first output in an in-memory data structure. The first output may then be obtained from the in-memory data structure for use as an input to a subsequent API test that is executed. The first API test and the second API test, in one embodiment, are specified in declarative metadata. In such an embodiment, the declarative metadata may be XML metadata.
[0016] Other features and advantages of the invention will become readily apparent upon review of the following description in association with the accompanying drawings, where the same or similar structures are designated with the same reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
[0018] FIG. 1 is a block diagram representation of an architecture which includes a diagnostics and application programming interface (API) testing framework in accordance with an embodiment of the present invention.
[0019] FIG. 2 is a process flow diagram which illustrates the steps associated with one method of running an API test in accordance with an embodiment of the present invention.
[0020] FIG. 3 is a process flow diagram which illustrates the steps associated with one method of invoking an entity specified in declarative metadata, e.g., one embodiment of step 208 of FIG. 2 , in accordance with an embodiment of the present invention.
[0021] FIG. 4 is a block diagram representation of a path followed by a declarative metadata structure, e.g., and XML schema definition of an API test, to a test interface in accordance with an embodiment of the present invention.
[0022] FIG. 5 is a block diagram representation of a schema definition written in declarative metadata, e.g., an XML schema definition, for an API test in accordance with an embodiment of the present invention.
[0023] FIG. 6 is a representation of an XML schema definition of an API test in accordance with an embodiment of the present invention.
[0024] FIG. 7 is a diagrammatic representation of an XML tag structure which is used within an overall test application in accordance with an embodiment of the present invention.
[0025] FIG. 8 is a representation of one test application in accordance with an embodiment of the present invention.
[0026] FIG. 9 a is a block diagram representation of how a result of a test may be pipelined in accordance with an embodiment of the present invention.
[0027] FIG. 9 b is a block diagram representation of how an API test may utilize both pipeline and non-pipelined input and how an API test may generate both pipeline and non-pipelined output in accordance with an embodiment of the present invention.
[0028] FIG. 10 is a block diagram representation of a process of field masking in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] In the description that follows, the present invention will be described in reference to embodiments that test subsystems on a platform for a software application, such as a database application. However, embodiments of the invention are not limited to any particular architecture, environment, application, or implementation. For example, although embodiments will be described in reference to database applications, the invention may be advantageously applied to any software application. Therefore, the description of the embodiments that follows is for purposes of illustration and not limitation.
[0030] A framework which enables application programming interface (API) testing to occur without requiring that a specific API test be written for each test case enables testing of API application code to occur efficiently. Such a framework may allow for relatively efficient development of API tests by effectively allowing functionality associated with different API tests to be shared and reused. Such a framework allows an API to be tested without requiring that significant amount of software be written, and further enables multiple API tests to be chained together, an API may be comprehensively tested in an efficient manner. Hence, the reliability of an API may be enhanced as developers may be more willing, as well as able, to more fully test an API since the need to write a significant amount of software code is effectively eliminated.
[0031] FIG. 1 is a diagrammatic representation of an implementation architecture of a diagnostics and API testing framework in accordance with an embodiment of the present invention. An architecture 100 , which may be part of a computing system which includes processors and storage devices on which code devices associated with the architecture are stored, is arranged to provide a diagnostics and testing framework, e.g., an API testing framework. Within architecture 100 , repositories 138 , 148 are arranged to store data, e.g., repository 148 is arranged to store information pertaining to an API test. Repository 138 , which may be a database that stores tables, is arranged to be accessed by a database metadata provider. Similarly, repository 148 , which is arranged to store XML files is arranged to be accessed by an XML metadata provider 140 through an API test XML adapter 144 a . It should be appreciated that although XML files are discussed, the files stored for use in the implementation architecture may generally be substantially any files written using declarative metadata.
[0032] Database metadata provider 136 and XML metadata provider 140 are source specific providers that are arranged to transform data into a format that may be understood by a execution engine or layer 112 . While only database metadata provider 136 and XML metadata provider 140 are shown, any number of providers may generally be included that interface with execution engine 112 via a metadata provider interface 124 . Metadata provider interface 124 is generally arranged such that providers such as database metadata provider 136 and XML metadata provider 140 may communicate with execution engine 112 .
[0033] API test XML adapter 144 a is arranged to enable custom tags of an XML schema definition, which will be described below with reference to FIGS. 5 and 6 , to be read and written. In general, API test XML adapter 144 a is an interface that is arranged to persist XML data. API test XML adapter 144 a may marshal XML test data into a custom test object, e.g., a custom Java test object, at run-time that may effectively be executed by execution engine 112 . It should be understood that other types of text XML adapters, as for example a SQL test XML adapter 144 b , may be provided to interface with XML metadata provider 140 to enable custom tags of an XML schema definition associated with a SQL test to be read and written. XML metadata provider 140 is generally arranged to identify an appropriate test XML adapter or test type adapter for a test to be executed.
[0034] When execution engine 112 runs tests such as an API test, execution engine 112 accesses a security provider interface 116 which provides a security model that is used to enforce authorization rules which control access to a test and to test results. That is, security provider interface 116 is arranged to enforce security in terms of who may run a test and who may view the output of a test. In one embodiment, security provider interface 116 delegates a call to a security provider (not shown).
[0035] Execution engine 112 also logs information, e.g., the output of tests, for reporting purposes using a log provider interface 120 . Log provider interface 120 is effectively a reporting storage interface. Repositories such as an XML writer 128 and a database writer 132 which are interfaced with execution engine 112 through log provider interface 120 are arranged to store reports which are persisted in log files. XML writer 128 may be used for the storage of reports associated with XML metadata, while database writer 132 may be used for the storage of reports associated with database metadata.
[0036] In general, execution engine 112 includes the core execution logic associated with architecture 100 , and delegates calls or logic to appropriate sources. Execution engine 112 may take user commands and cause a test to be run and registered, and also cause test results or output to be displayed as appropriate. For example, when an API test is to be run, execution engine 112 calls into a test interface 152 which effectively provides handshaking between execution engine 112 and adapters such as API test adapter 168 , SQL test adapter 172 , and any custom adapters 176 .
[0037] For each test type, an adapter which is arranged to run the test type is effectively interfaced with test interface 152 . By way of example, API test adapter 168 is arranged to include the logic that is needed in order to understand a test definition provided in an XML file. API test adapter 168 is arranged to instantiate the method identified in the XML file, and to provide the results of the instantiation to execution engine 112 . In general, adapters such as API test adapter 168 transform declarative metadata into objects that implement test interface 152 . At runtime, when execution engine 112 runs a test, an object that implements test interface 152 invokes desired APIs on a desired entity with prescribed input parameters, and also captures output parameters and performs comparisons to determine the success or the failure of the test.
[0038] In general, an adapter such as API test adapter 168 is a program which has the ability to transform data, e.g., declarative metadata, from one format into another such that the data may be understood by execution engine 112 . API test adapter 168 , for example, transforms test metadata into a format that is understood by execution engine 112 .
[0039] Java diagnostic tests 156 which contain runtime information, a PL/SQL adapter 160 , a declarative adapter 164 , API test adapter 168 , SQL test adapter 172 , and any custom adapters 176 are all arranged to interface with execution engine 112 via test interface 152 . Such elements effectively rewrite data into a language or format that is understood by test interface 152 . Each of the elements which are effectively plugged into test interface 152 include a generic adapter portion or a common layer 154 . Specifically, each element plugged into test interface 152 essentially extends the functionality or logic associated with generic adapter portion 154 . In one embodiment, while generic adapter portion 154 effectively handles common tags associated with a declarative metadata file, the extensions associated with each element, e.g., the extensions off of generic adapter portion 154 associated with API test adapter 168 , handle custom or unique tags within the declarative metadata file. It should be appreciated that API test adapter 168 may include the capabilities associated with API test XML adapter 144 a . That is, API test adapter 168 may be arranged to persist XML data and to read and write custom tags, in addition to being arranged to provide a running test logic interface.
[0040] Extensibility enables custom adapters 176 to be written as needed, and then plugged into architecture 100 when additional functionality within architecture 100 is desired. Extensibility further enables such custom adapters 176 to utilize and build off of generic adapter portion 154 .
[0041] A rendering interface 108 , e.g., a user interface rendering interface, is in communication with execution engine 112 , and enables information pertaining to tests to be displayed to a user. User interface rendering interface 108 may be JSP fronted for web-based user interfaces, for example, and generally provides an abstraction away from what a user interface is expected to look like. It should be appreciated that JSP is just one example of a suitable user interface technology. There may be several different user interfaces that may be used to present diagnostics data to a user. In general, user interfaces and commandline user interfaces may be in communication with user interface rendering interface 108 through renderers 104 . For each available user interface, an associated user interface renderer 104 that implements method or routines prescribed by user interface rendering interface 108 typically exists. That is, diagnostic user interface renderers 104 implement user interface rendering interface 108 . Such user interface renderers 104 may include, but are not limited to, a diagnostics renderer 104 a , a Jdeveloper renderer 104 b , a command line or text renderer 104 c , and an integration renderer 104 d , which may effectively be used to record a test when an application such as Winrunner is interfaced with integration renderer 104 d . Winrunner 104 d is available commercially from Mercury Interactive of Mountain View, Calif. In order for communication to be achieved with a user interface layer (not shown), execution engine 112 invokes the methods of a suitable user interface renderer 104 that is associated with a specified user interface.
[0042] With reference to FIG. 2 , the steps associated with running an API test will be described in accordance with an embodiment of the present invention. A process 200 of running an API test begins at step 204 in which a declarative metadata schema definition is generated. The declarative metadata schema definition is generated to design an API test application that an API test tool may use to determine what to test. One configuration of an API test application will be described below with respect to FIG. 7 . In the described embodiment, the declarative metadata used is XML, although it should be appreciated that substantially any type of declarative metadata may be used to generate a schema definition.
[0043] Once the declarative metadata schema definition is generated, an entity, e.g., a method, that is specified in the declarative metadata is invoked using an execution engine associated with the API test tool in step 208 . One method of invoking an entity is described below with reference to FIG. 3 . After the entity is invoked, the process of running an API test is completed.
[0044] Referring next to FIG. 3 , the steps associated with one method of invoking an entity specified in declarative metadata will be described in accordance with an embodiment of the present invention. That is, one embodiment of step 208 of FIG. 2 will be described. A process of invoking an entity beings at step 304 in which an execution engine accesses a metadata provider interface to obtain metadata from an appropriate provider or repository. As previously discussed, the metadata provider interface generally allows access to both a database metadata provider and an XML metadata provider. Hence, in step 308 , it is determined whether XML metadata is to be obtained from the XML metadata provider. When it is determined that XML metadata is not to be obtained from the XML metadata provider, then the indication is that metadata is to be obtained from another source, e.g., a database metadata provider. Accordingly, process flow proceeds to step 316 in which metadata is obtained from a source other than an XML metadata provider.
[0045] Alternatively, if it is determined in step 308 that XML metadata is to be obtained from the XML metadata provider, then in step 312 , and API test type adapter, i.e., an API test XML adapter, is accessed by the execution engine through the metadata provider interface. Metadata, which in this case is XML metadata, is then obtained in step 316 . Once metadata is obtained in step 316 , the execution engine uses a test interface to call into an appropriate adapter class in step 320 . In one embodiment, the appropriate adapter class may be an API test adapter class.
[0046] After the appropriate adapter class is called in step 320 , the adapter class is invoked by the test interface in step 324 . Then, the API test is run using the adapter class in step 328 . Once the test is completed, the execution engine may access a log provider interface in order to log results of the test in step 332 . Upon logging the results of the test, the process of invoking an entity specified in declarative metadata is completed.
[0047] FIG. 4 is a block diagram representation of a path followed by a declarative metadata structure, e.g., and XML schema definition of an API test, to a test interface in accordance with an embodiment of the present invention. A declarative metadata structure 402 is generally provided by a user and may be stored in a repository. Using an appropriate test adapter, as for example API test adapter 168 of FIG. 1 , declarative metadata structure 402 is transformed into a programmatic representation 406 . As discussed above, a test adapter is arranged to transform data, e.g., a declarative metadata structure 402 , into a form that is understood by a test interface. Once the data is transformed into programmatic representation 406 , programmatic representation 406 is passed to a test interface 410 which cooperates with the appropriate test adapter to instantiate a method defined in declarative metadata structure 402 . Programmatic representation 406 is generally a diagnostic test object that is arranged to implement test interface 410 which is effectively understood by an execution engine.
[0048] In general, each test that is specified in declarative metadata, e.g., XML, is specified with a set of information in the form of tags. With reference to FIG. 5 , the components of an XML schema definition for an API test will be described in accordance with an embodiment of the present invention. An XML schema definition specifies how data should be defined for an API test. A test 500 is typically specified with an entity to test 504 , e.g., an API that is to be tested or an API test type. Entity to test 504 will generally include an attribute which an XML engine may use to determine what sort of entity is to be tested. In one embodiment, entity to test 504 may be a Java API test that may be invoked using Java reflection to instantiate an object of the appropriate Java class.
[0049] Test 500 also specifies input parameters 508 , if there are any, which are to be used in test 500 , as well as any output parameters 512 , if there are any, which are to be produced by test 500 . Input parameters 508 may be persisted in a run time data store, or values associated with input parameters 508 may be retrieved from the run time data store.
[0050] An error condition 516 , or an output exception, that is specified in test 500 is arranged to indicate an condition which may cause test 500 to return an error. In one embodiment, error condition 516 may effectively be an output parameter, i.e., output parameters 512 may not necessarily be specified if error condition 516 is specified. Error message and fix information 520 is specified to indicate what caused an error and what may be done to correct the error. Typically, the error message and fix information will be displayed on a user interface in the event that test 500 fails.
[0051] FIG. 6 is a representation of an XML schema definition of an API test in accordance with an embodiment of the present invention. An XML schema definition 600 includes an API test type tag 604 that specifies an API to test. While the API to test may be substantially any suitable API, the API is shown as being an account creation API. Input parameters tag 608 which is specified in XML schema definition 600 is arranged to include, but is not limited to including, a first name of a potential account holder 628 a , a last name of the potential account holder 628 b , and a date of birth of the potential account holder 628 c . Output parameters tag 612 generally includes an account number for a newly created account. A new account number 632 may be stored such that XML schemas for other API tests may access new account number 632 , i.e., new account number 632 may be pipelined. The pipelining of data will be discussed below with reference to FIGS. 9 a and 9 b . An error condition tag 616 is specified for a normal error, and includes error message and fix information 620 . In the embodiment as shown, XML schema definition 600 also includes a description tag 636 which is used to indicate what the API specified in entity to test 604 is arranged to do.
[0052] Some API tests which are specified within XML schema definitions or, more generally, declarative metadata, such as XML schema definition 600 of FIG. 6 may be a part of a test suite. A test suite is generally an overall test application which includes a plurality of API tests. Referring next to FIG. 7 , an XML tag structure which is used within an overall test application will be described in accordance with an embodiment of the present invention. An XML tag structure for a test application 700 includes a test suite tag 702 which may identify a name of the test suite, and provide some information pertaining to the test suite. Test suite 702 generally contains a plurality of tests that test a particular piece of functionality. Since a test suite typically includes a group of tests, e.g., a logical group of tests, test type tags such as test type tag 706 are effectively a component of test suite 702 . As shown, test type tag 706 may be an API test type tag.
[0053] In one embodiment, a test application represents an overall product that is being tested, and may include one or more test suites. Substantially all test suites or, more generally, tests specified in a test application are pertinent to the overall product that is being tested. While any number of attribute may be specified with a test application, a test application is typically specified with at least a short name for the test application, a full name for the test application, and a file version of the test application.
[0054] A service bean information tag 710 , which may be specified under test type tag 706 , is arranged to contain information relating to a service name and configuration information. Also specified under test type tag 706 are an input parameters tag 714 , an output parameters tag 722 , a description tag 730 , an error information tag 734 , and an output exception tag 738 . Input parameters tag 714 is arranged to encapsulate any number of input parameter tags 718 . Similarly, output parameters tag 722 is arranged to encapsulate any number of output parameter tags 726 .
[0055] FIG. 8 is a representation of one test application in accordance with an embodiment of the present invention. A test application 800 may be specified with a name and an identifier that uniquely identifies test application 800 . A test suite 802 , which may be considered to be a first level of hierarchy within test application 800 , includes a component identifier which indicates a group of tests being run within test application 800 . Included in test suite 802 are any number of test types 806 a - d which, in the embodiment as shown, are API tests types which are specified with a language, an identifier, a method name, and a class.
[0056] Each test type 806 a - d , e.g., test type 806 c , is specified with additional information, as discussed above with respect to FIGS. 5 and 6 . The additional information typically includes input parameters 814 , where each input parameter 818 is specified within input parameters 814 . Similarly, the additional information specified in test types such as test type 806 c also includes output parameters 822 , where each output parameter 826 is specified within output parameters 822 . Error information 834 is also typically specified within test types with a type. An error message and error fix information are also included within error information 834 . In the described embodiment, test type 806 c further includes a description 830 which describes test type 806 c.
[0057] It should be appreciated that often data used by or created by a test such as an API test may be shared with other test applications or API tests. That is, data may be pipelined by storing data in variables that are accessible to multiple API tests. For example, an API test that creates a new account number may store the new account number in a variable that is accessed by an API test that obtains account balances in order to obtain a balance for the new account number. Hence, the new account number is pipelined in that it may be created by one API test and utilized by a second API test.
[0058] Pipelining generally involves using output values of one test as an input parameter for a subsequent test. FIG. 9 a is a block diagram representation of how a result of a test may be pipelined in accordance with an embodiment of the present invention. A first API test 902 produces a result 914 that is stored in an in-memory data structure 910 . In one embodiment, in-memory data structure 910 may be a runtime data store in a Java virtual machine. Result 914 is pipelined in that a second API test 906 retrieves result 914 from in-memory data structure 910 , and uses result 914 , i.e., as an input parameter. It should be appreciated that first API test 902 and second API test 906 are generally in a single test suite, and that once all tests in the test suite are executed, in-memory data structure 910 is effectively emptied.
[0059] In general, an API test that uses pipelined data as an input parameter may also create pipelined data as an output parameter. Additionally, an API test that produces pipeline data may also produce an output parameter that is not pipelined, and an API test that uses pipeline data as an input parameter may also use an input parameter that is not pipelined. With reference to FIG. 9 b , an API test which utilizes both pipelined and non-pipelined input parameters as well as an API test which generates both pipelined and non-pipelined output parameters will be described in accordance with an embodiment of the present invention. A first API test 922 uses an input parameter 942 during execution, and produces a first output value 924 that is stored in an in-memory data structure 930 . Input parameter 942 is typically a parameter that is specified in the declarative metadata associated with first API test 922 . It should be appreciated that although first API test 922 may be arranged to provide substantially only first output value 924 , first API test 922 may, in some embodiments, also provide a second output value 946 , as shown. In an embodiment in which second output value 946 is produced and not stored in in-memory data structure 930 , second output value 946 may be substantially discarded after being used in an associated comparison and displayed on a user interface as appropriate.
[0060] A second API test 926 retrieves value 924 from in-memory data structure 930 and uses value 924 as a first input parameter. Second API test 926 also uses a second input parameter 950 that is generally provided in the declarative metadata associated with second API test 926 . Using value 924 and parameter 950 as inputs, second API test 926 produces a third output value 954 which is stored in in-memory data structure 930 . Since third output value 954 is stored in in-memory data structure 930 , third output value 954 is effectively pipelined as third output value 954 may be accessed by and used as an input to another API test (not shown).
[0061] As a part of an API test tool, the ability to mask out values which are essentially irrelevant to an API test enables many API test failures to be prevented. For instance, values which change and are not particularly relevant to an API test may cause failures when compared to “expected” values. By way of example, certain attributes such as an account number may not be relevant in a particular API test. In order to reduce the likelihood of failures caused when essentially irrelevant value is compared to an “expected” value, such values may be masked out using a field mask.
[0062] With reference to FIG. 10 , the field masking of values which are not relevant to a test being run will be described in accordance with an embodiment of the present invention. A schema definition 980 may specify a field masking attribute 984 which indicates that at least one output value of a test run using schema definition 980 is to be masked. As shown, output 988 from a test run using schema definition 980 includes a value 992 that is masked out such that value 992 may be ignored.
[0063] Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. By way of example, while Java has generally been described as an API test type language, substantially any test type language may be used. Suitable test type languages may include, but are not limited to, PL/SQL.
[0064] While adapters which use a test interface have been described as utilizing or extending a generic adapter portion, some adapters may not necessarily make use of the generic adapter portion. For instance, a custom adapter that interfaces with the test interface may be created without utilizing any component of a generic adapter portion that may be used by other elements.
[0065] In one embodiment, pipelining is permitted across tests within one test suite, but is not permitted across different test suites. It should be appreciated, however, that in some instances, pipelining may not be limited to being used only with tests within one test suite. For example, in lieu of cleaning out a runtime data store after all tests within a test suite are executed, the data in the runtime data store may instead be persisted. Persisting the data in the runtime data store may enable other tests suites may utilize the data.
[0066] Generally, the steps associated with the methods of the present invention may vary widely. Steps may be added, removed, altered, and reordered without departing from the spirit or the scope of the present invention. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | Methods and apparatus for enabling the framework and the application code associated with an application programming interface (API) to be efficiently and comprehensively tested are disclosed. According to one aspect of the present invention, a structure that defines an API test in declarative metadata includes an entity to be tested, a first metadata arrangement, and a second metadata arrangement. The first metadata arrangement includes any data to be used when the entity is tested, and the second metadata arrangement includes any expected outputs associated with testing the entity. | 6 |
BACKGROUND
The present invention relates to a brazed-plate heat exchanger, whose passages contain at least one corrugated fin of the type comprising, in cross section, a repeated corrugated pattern which extends between two upper and lower extreme planes defined by the plates of the exchanger.
The invention is in particular applicable to gas—gas cryogenic exchangers for air distillation apparatuses, such as the main heat exchange line of these apparatuses, which cools the incoming air by indirect heat exchange with the cold products from the distillation column.
The corrugated fins in question are widely used in brazed-plate heat exchangers, which have the advantage of offering a large heat exchange surface area in a relatively small volume, and of being easy to manufacture. In these exchangers, the fluid flows may be cocurrent, countercurrent or crosscurrent flows.
FIG. 1 of the appended drawings shows, in perspective, with partial cutaways, an example of such a heat exchanger, of conventional structure, to which the invention is applicable. In particular, it may involve a cryogenic heat exchanger.
The heat exchanger 1 shown consists of a stack of parallel rectangular plates 2 which are all identical and which between them define a plurality of passages for fluids to be brought into indirect heat exchange relationships. In the example shown, these passages are, in succession and cyclically, passages 3 for a first fluid, 4 for a second fluid and 5 for a third fluid.
Each passage 3 to 5 is bordered by closure bars 6 which define the passage, leaving inlet/outlet windows 7 of the corresponding fluid free. Placed in each passage are spacer waves or corrugated fins 8 acting both as thermal fins, as spacers between the plates, especially during brazing and in order to avoid any deformation of the plates when using pressurized fluids, and for guiding the fluid flows.
The stack of plates, closure bars and spacer waves is generally made of aluminum or aluminum alloy and is assembled in a single operation by furnace brazing.
Fluid inlet/outlet boxes 9 , of semicylindrical overall shape, are then welded to the exchanger body thus produced so as to sit over the rows of corresponding inlet/outlet windows, these boxes being connected to fluid feed and discharge pipes 10 .
There are various types of spacer waves 8 . Thus mention may be made of straight fins, with rectilinear, possibly perforated, generatrices, fins known as “herringbone” fins, with sinuous generatrices, louvered fins, the wave legs of which have rows of recesses, and partially offset or “serrated” fins.
In these various fins, the wave may have a square, rectangular, triangular, sinusoidal, etc., cross section.
SUMMARY
A brazed-plate heat exchanger apparatus comprising:
(i) a stack of parallel plates wherein said parallel plates define a plurality of generally flat-shaped fluid flow passages; (ii) closure bars wherein said closure bars define passages; and (iii) corrugated fins wherein said corrugated fins comprise, in cross section, a repeated corrugated pattern extending between two upper and lower extreme planes defined by two adjacent plates of the exchanger,
wherein said pattern comprises a basic corrugated pattern-comprising wave legs connected by wave crests and wave troughs and wherein said pattern are modified by a subpattern which comprises additional exchange surfaces located between at least some pairs of wave legs, wherein said additional exchange surfaces are located at an intermediate level between the two extreme planes.
The aim of the invention is to improve the thermal performance of exchanges with corrugated fins. To this end, the subject of the invention is a brazed-plate heat exchanger, of the type comprising a stack of parallel plates which define a plurality of generally flat-shaped fluid flow passages, closure bars which define these passages, and corrugated fins placed in the passages, at least some of the corrugated fins being of the type comprising, in cross section, a repeated corrugated pattern extending between two upper and lower extreme planes defined by two adjacent plates of the exchanger, characterized in that the pattern comprises a basic corrugated pattern comprising wave legs connected by wave crests and wave troughs, this basic pattern being modified by a subpattern which defines, between at least some pairs of wave legs, additional exchange surfaces located at an intermediate level between the two extreme planes.
According to other optional aspects:
the subpattern defines a subcorrugation which extends only over a portion of the distance which separates the two extreme planes. the subpattern comprises at least one nonvertical part located at an intermediate level between the two extreme planes. the subpattern further comprises pairs of limbs which connect the nonvertical parts alternately to a wave crest and to a wave trough. the limbs are vertical. the subpattern comprises at least one additional oblique exchange surface. the subpattern has a V-shaped section. the subpattern comprises a step adjacent to at least some legs of the main pattern. the fin is partially offset. the offset distances ensure that the main pattern is offset both with respect to itself and with respect to the subpattern. the pattern repeats every N rows of waves, where N ≧3 and in particular, N=4. at least some parts of at least some troughs and/or subpatterns comprise a notch in at least one leading and/or trailing edge and in at least part of their height or their width. the wave has a square, rectangular, triangular or sinusoidal cross section. the basic corrugated pattern is constant over the entire length of the two extreme planes.
The following will mainly concern serrated fins, but it will be understood that the invention is also applicable to other types of fins described above.
Exemplary embodiments of the invention will now be described with respect to the appended drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawing, in which like elements are given the same or analogous reference numbers and wherein:
FIG. 1 illustrates a conventional heat exchanger as know in the art;
FIG. 2 shows, in perspective, a serrated fin according to the invention;
FIG. 3 is an end view of this fin;
FIG. 4 is an end view of a variant;
FIG. 5 shows, in perspective, another serrated fin according to the invention;
FIG. 6 is a view in exploded perspective of the fin of FIG. 5 ;
FIG. 7 is an end view of the fin of FIG. 5 ; and
FIG. 8 is an end view of another serrated fin according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
A brazed-plate heat exchanger apparatus comprising:
(i) a stack of parallel plates wherein said parallel plates define a plurality of generally flat-shaped fluid flow passages; (ii) closure bars wherein said closure bars define passages; and (iii) corrugated fins wherein said corrugated fins comprise, in cross section, a repeated corrugated pattern extending between two upper and lower extreme planes defined by two adjacent plates of the exchanger,
wherein said pattern comprises a basic corrugated pattern-comprising wave legs connected by wave crests and wave troughs and wherein said pattern are modified by a subpattern which comprises additional exchange surfaces located between at least some pairs of wave legs, wherein said additional exchange surfaces are located at an intermediate level between the two extreme planes.
The serrated fin 1 shown in FIGS. 2 and 3 has an overall main corrugation direction Dl and comprises a large number of adjacent wave rows 12 A, 12 B, . . . , which are all identical and are oriented in a direction D 2 perpendicular to the direction Dl.
For convenience in the description, it will be assumed that, as shown in FIG. 2 , the directions D 1 and D 2 are horizontal, similarly with the plates 2 of the exchanger.
Each wave row 12 has, in cross section perpendicular to D 1 , a basic pattern M which comprises two vertical wave legs 13 . With respect to an overall sense F of the flow of the fluid along the direction D 1 in the passage in question, each leg comprises a leading edge 14 and a trailing edge 15 . The legs are alternately connected along their upper edge by means of a rectangular, flat and horizontal wave crest 16 , and along their lower edge by means of a wave trough 17 which is also rectangular, flat and horizontal.
The basic pattern M is modified by a subpattern M 1 consisting of a rectangular projection extending downward in the middle of each crest 16 and upward in the middle of each trough 17 .
Each subpattern M 1 consists of one flat end part 18 located half way between the extreme planes defined by the adjacent plates 2 , and two vertical limbs 19 which connect the edges thereof to the corresponding crest 16 or trough 17 .
Thus, each subpattern forms a notch which comes in between the two adjacent legs 13 . This notch defines three additional exchange surfaces, that is a horizontal exchange surface 20 and two vertical exchange surfaces 21 .
The rows 12 are offset one with respect to another in the direction D 2 , alternately in one sense and in the other. By using the term “pitch” to refer to the distance p which separates two successive legs 12 (ignoring the thickness e of the thin sheet material forming the wave), the offset is alternately p/6 in one sense and in the other, while the notch width M 1 is p/3.
Thus, each row 12 is connected to the following row 12 by means of the crests 16 , along right-handed segments 22 of length p/6, and by means of the troughs 17 , along The serrated fin 1 shown in FIGS. 2 and 3 has an overall main corrugation direction Dl and comprises a large number of adjacent wave rows 12 A, 12 B, . . . , which are all identical and are oriented in a direction D 2 perpendicular to the direction Dl. right-handed segments 23 of the same length p/6. The offset planes are the vertical planes such as P AB and the offset lines, seen from the top, are denoted by 24 .
Moreover, l is used to denote the length of each row 12 in the direction D 1 , this length being called the “serration length”, and h is used to denote the height of the fin.
In practice, the shapes of various wave parts may differ to a greater or lesser degree from the theoretical shapes described above, especially with regard to the flatness and the rectangular shape of the facets 13 and 16 to 19 , and the verticality of the facets 13 and 19 .
Seen from the end ( FIG. 3 ), the patterns M are offset sideways with respect to themselves and with respect to the patterns M 1 , that is to say that the legs 13 of a given serration row 12 each appear between a leg 13 of the adjacent rows and a limb 19 of a neighboring subpattern M 1 . Conversely, the limbs 19 of the same row 12 each appear either between two limbs 19 , or between a limb 19 and a leg 13 , of the adjacent rows 12 .
Because of the presence of the subpatterns M 1 , the flow separation is increased at each offset line 24 , which increases the temperature difference between the fluid and the fin, thus increasing the heat flux exchanged. The presence of additional leading edges 20 and 21 further generates turbulence within the fluid, which promotes heat transfer by convection toward the core of the flow and not by conduction through the limiting layer, which promotes heat exchange.
The variant of FIG. 4 differs from that of FIG. 3 by a greater depth of the notches M 1 , this depth changing from about h/2 to 2h/3. In this way, the preferential flow regions, which miss out on the beneficial effect of the notches M 1 described above, are reduced.
With the same objective, FIGS. 5 to 7 show a serrated fin whose pattern M+M 1 repeats not every other row, but one row in N, where N≧3. This makes it possible to increase the symmetry of flow. In the example shown, N=4. Four successive rows 12 A to 12 D will subsequently be described below.
As previously, each row has the same rectangular basic pattern M, comprising vertical legs 13 spaced apart by the pitch p and alternately connected by a wave crest 16 of width p and by a wave trough 17 of the same width p. The pattern M is modified by a subpattern M 1 A to M 1 D:
subpattern M 1 A: in each upwardly open corrugation, the lower part of the right leg 13 is deformed by a step which comprises a horizontal part 24 located half way up the leg and a vertical part 25 located half way between this leg and the other leg of the corrugation. Thus, the lower half of the leg and the right half of the adjacent wave trough are removed, as shown by chain line; subpattern M 1 B: in each downwardly open corrugation, the upper part of the left leg 13 is deformed by a similar step, that is to say a rectangular step of dimensions p/2 and h/2; subpattern M 1 C: in each upwardly open corrugation, the lower part of the left leg 13 is deformed by a similar step. This subpattern is therefore symmetrical with respect to the subpattern M 1 A; subpattern M 1 D: in each downwardly open corrugation, the upper part of the right leg 13 is deformed by a similar step. This subpattern is therefore symmetrical with respect to the subpattern M 1 B;
Moreover, in this embodiment, the offset from one row to the next is p/2, alternating in one sense and in the other (?). FIGS. 5 and 6 indicate two neighboring vertical planes P 1 and P 2 , in order to make it easier to understand the structure of the fin.
The embodiment of FIG. 8 is derived from that of FIG. 3 in that each subpattern M 1 is triangular and is no longer rectangular or square. Thus two oblique leading edges 25 , which are symmetrical with respect to the vertical plane of symmetry P of the wave, are inserted into each wave.
In the example shown, the height of the triangle is h/2, but, as before, it may have a different value, especially a value greater than h/2 in order to reduce the preferential flow regions.
In all the above examples, high thermal performance of the exchanger, with highly divided and turbulent flow and with a two-dimensional, or even three-dimensional configuration is obtained.
Note that the fins may be manufactured by simple folding of a flat product on a press or using a cogged wheel, as for the conventional corrugated, especially serrated, fins. This is because the surfaces are all developable, such that it is enough to match the profile of the folding tools.
The presence of the subpatterns M 1 causes passage restriction at the offset lines, and therefore pressure drops. These pressure drops can possibly be reduced by providing notches carefully placed in at least some leading and/or trailing edges of the patterns M and/or M 1 . These notches will preferably be located facing the leading and/or trailing edges of the subpatterns M 1 , or therewithin, as indicated in chain line by 26 in FIG. 2 .
Whatever the fin type, the latter may be made either from solid sheet metal, or from perforated sheet metal or sheet metal provided otherwise with apertures.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above. | The invention concerns a heat exchanger which includes a stack of plates defining passages, containing corrugated fins which include a transverse section with repeated corrugated pattern extending between two upper and lower end planes. The pattern includes a base corrugated pattern that includes corrugated legs linked to corrugated summits and corrugated bases, this base pattern being modified by a sub-pattern which defines, between at least some corrugated legs, additional leading edges located at an intermediate level between the end planes. The invention is applicable to cryogenic gas—gas heat exchangers. | 5 |
BACKGROUND OF THE INVENTION
A very successful fish stringer widely present on the market consists of a length of chain with a plurality of safety-pin-like fish clips secured to the chain at spaced intervals. The sharp end of the clip wire is normally lodged in a shielded pocket. To string a fish, the end is sprung out of the socket and threaded through the lower and upper lips of the fish and closed again. The bight of the clip permits enough jaw movement of the fish so that it can breathe freely while it is on the stringer. This type of stringer does a notably good job of keeping the fish alive until the day's fishing is done. The spaced intervals of the clips prevent crowding of the fish on the stringer and eventual jaw destruction and suffocation.
In pier and bridge fishing common in Florida and elsewhere, the fishing platform may be 12' to 20' or more above the water. Carrying such a length of line or chain with clips attached would present difficulties in tangling. Also, tailoring the length of the line to a variety of fishing locations presents obvious difficulties.
The lip hooking of the fish also raises problems in regard to a conventional stringer. The lips, while fairly strong and tough, can tear through. Such tearing is a likely eventuality when the fishing is good and the stringer must frequently be raised 12' in the air, for instance, to add another fish to it, the fish already on the stringer jerking and flopping. Even if the already caught fish should not shake themselves free, damage to the jaws and breathing mechanism is likely such that the fish may die prematurely.
SUMMARY OF THE INVENTION
This invention is directed to a fish stringer and to the link forming a part thereof which avoids the above difficulties. The link itself consists of a closed loop of stiff wire to which a fish clip is secured, the link being adapted for a secure, sliding attachment to a line, cable or chain intermediate its length such that the fish holders can be carried separately from the line and the length of the line be determined according to the particular requirements of the fishing location. The separate and detached transport of the line and the holders greatly reduces tangling. The closed-loop nature of the link minimizes tangling as among the holders themselves. The length of the links on the line is substantial so as to afford good spacing for the fish on the stringer.
The ready attachability of the holders to the line between its ends permits the attachment of each fish individually to the line at the fishing platform and permitting the fish and holder to drop down into the water without the necessity of hauling up the stringer with the fish already caught on it and without the necessity of untying the line from its anchoring point on the bridge or pier.
Attention is directed to the following patents, the first two particularly.
______________________________________Patent No. To Issued______________________________________2,125,770 S. Dabroski Aug. 2, 19383,055,332 V. J. Linsdeau Sept. 25, 19622,111,958 D. M. Bardon Mar. 22, 19382,217,972 W. E. Smith Oct. 15, 19403,120,715 A. E. Long Feb. 11, 1964______________________________________
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of a portion of a stringer line with a pair of the fish holders mounted thereto;
FIG. 2 is a front elevation of the fish holder of FIG. 1;
FIG. 3 is an end elevation of the link of FIG. 2;
FIG. 4 is a perspective view of a link of the invention and a section of stringer cord illustrating the beginning of the attachment of the link to the cord;
FIG. 5 is a view similar to FIG. 4 illustrating a final step in the attachment of the link to the cord;
FIG. 6 is a fragmentary front elevation similar to FIG. 2 illustrating a modified form of the link; and
FIG. 7 is an end elevation of the link of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 is shown a length of fish stringer line or cord 10 with two fish holders 12 mounted thereto. The fish holders consist of a clip 14 and a link 16. The cord 10 may be rope, chain, or cable, but it must be flexible. The cord should have a stop on one end thereof, here shown to be a relatively large washer 18 to which the cord is knotted.
The link consists of a length of stiff wire, for instance 14 gauge iron wire, which may be plated for corrosion resistance. The wire is formed to have a pair of oppositely wound coils 20 and 22 formed therefrom having a common center line or axis. A bridging portion or tongue 24 which may be pointed, round or straight (FIG. 6) bridges the adjacent ends of the coils and extends beyond the periphery of the coils. In the drawings, the left hand coil 20 has a right hand twist to it and the right hand coil 22 has a left hand twist to it. As illustrated in FIGS. 1-5, the coils are wound through about 540° and the turns 25, 26 of each coil are imperatively spaced apart by at least the diameter of the cord, chain or cable which is to constitute the string for the stringer. The wire at the remote ends of the coils 20, 22 occupy a common plane tangent to the two coils 20, 22 and extend away from the coils convergently toward each other to a point of meeting 28 well spaced from the common axis of the two coils 20 and 22. The tongue extends from the coils a short distance parallel to the plane of the wires and tangent to the other side of the coils.
The link may perhaps be visualized better from one method of fabrication. If the wire were to be bent into a V shape (FIGS. 1-5) or with a U shape with divergent legs (FIG. 6) the apex at the center of the wire, the two arms of the wire laid against the same side of a cylindrical mandrel a short distance away from the apex, the apex positionally anchored to the mandrel, and the arms bent around the mandrel an equal number of turns in an outwardly spiraling fashion, the twin coil structure will be achieved. Thereafter, the unspiralled arm ends will be bent toward each other, first a slightly convergent angle to define legs 30 and then a sharply convergent angle to meet and define a crossbar 32 generally parallel to and well spaced from the axis of the coils.
The juncture of the legs at the point of meeting may be effected in various ways. In the embodiment illustrated in FIGS. 1 through 5, the two ends of the wire are formed into overlapping eyes 34, and one loop 36 of a swivel 38 passes through both eyes to hold them together. The other end 40 of the swivel mounts the fish clip 42. In the modification shown in FIGS. 6 and 7, the two ends of the wire are welded together as at 44. Where welding is the means for connecting the two ends of the wire, the weld may be located at any point in the length of the wire, the center of the tongue 24 linking the two coils, for instance. Other means of connecting the ends of the wire might be twisting them together, enclosing them in the ends of a sleeve, etc.
In the modification shown in FIGS. 6 and 7, it will be noted that the swivel 38 is mounted directly on the closed loop of the link 16 and thus is not positionally fixed on the link as is the modification shown in FIGS. 1 through 5.
It is possible to mount the fish clip 42 directly to the link without the interposition of the swivel 38.
The method of attaching the link to the stringer cord is particularly illustrated in FIG. 4 and 5. The link is oriented with the legs to the back and the tongue to the front. The cord is laid against the front of the legs 30 and in contact with the underside of the coils 20 and 22. A shallow loop of the cord between the legs is drawn backward and upward to lodge the cord in the upper part of the outermost turn of the coils as shown in FIG. 4. The loop is then drawn forwardly and down over the end of the tongue 24 and released (FIG. 5). This lodges the cord in the innermost turn of the coils and the link is thereby entrained on the cord with the cord extending along the common axis of the two loops. The link, thus, is attached in an encircling, sliding relationship to the cord between its ends without the necessity of threading an end of the cord through the coils. Detachment is similarly easy.
The tongue extending well away from the periphery of the coils requires substantial slack in the cord for the cord's passage thereover, so contributing to the security of the attachment.
The angularity or rotation of the coils 20 and 22 is subject to some variation. Obviously, there is no point in carrying their rotation farther than is necessary to obtain a positive, loss-proof attachment to the cord. The illustrated 540° angularity of the coils of FIGS. 1 through 5 serves this purpose well. There is no point in carrying the rotation farther than this degree in that it consumes additional wire and requires somewhat more effort to attach the link to the cord. The modification illustrated in FIGS. 6 and 7 illustrates coils wound through 540°. The extension of the tongue in both instances contributes to the security.
The limiting case, of course, is a bend of greater than 180° such that the plane of the tongue and of the legs intersect. Thus, a coil of 270° would provide fair security for the attachment of the link to the cord if the tongue projected well through and beyond the plane established by the legs. Such a link, however, in addition to lacking the security of a greater angularity of bend, would have the disadvantage of a substantial projection in two planes at right angles to each other which would add to the space required in transporting a number of such links.
A characteristic length of the link would be about two inches between the outer ends of the coils. This provides adequate spacing of the fish on the stringer cord. The links, of course, will stack on the cord. The links may be longer if larger fish are anticipated.
The convergence of the legs 30 permits independent swiveling of the links with a minimum of interference. | A fish stringer comprising a cord and a plurality of fish holders including links which are attachable to the cord between its ends in sliding relation thereon. | 0 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates in general to a toilet or water closet and, in particular, to a new and useful toilet or water closet having a stool which can be freely adjusted to any desired height according to the physical conditions of the person who is going to use the facility, such as, for example, when it is to be used by an adult, child, invalid or physically handicapped person.
DESCRIPTION OF THE PRIOR ART
In general, existing toilet or water closets are of the fixed height, stool-type which normally present difficulty to small children attempting to use the toilet by themselves. Such a construction also presents disadvantages to an invalid or a physically handicapped person who invariably must take an unnatural and, therefore, fatiguing position when seated. Such a construction also presents an uneasy feeling to a person who prefers the use of a Japanese style water closet in which one takes a crouching posture. In addition, the closet set thereof is of the so-called adult size and is too wide for children, resulting in frequent accidents and soiling of the floor.
SUMMARY OF THE INVENTION
The present invention comprises a construction which eliminates the above-noted disadvantages of the prior art constructions.
An object of the present invention is to provide a water closet having a stool the height of which can be adjusted by the use of a stool-height adjusting device.
Another object of the present invention is to provide a water closet having a stool with a closet seat, the width of which can be changed according to the adjusted height of the stool.
According to the present invention, there is provided a water closet, having a floor with a hole therein. A movable stool is disposed over the hole and a drum is formed integrally with the stool and extends vertically downwardly through the hole. A drum height adjusting means is connected to the drum for vertically moving the stool in relationship to the floor.
According to one aspect of the present invention, the drum height adjusting means includes guide wheels connected to the floor adjacent the hole which are in contact with the periphery of the drum for facilitating the smooth, vertical movement of the drum. A vertical screw rod is provided in the vicinity of the drum and threaded into a nut fixed to one end of the stool. The screw rod is fixed to the floor by suitable means and is provided with a bevel gear. A driving mechanism is provided for rotating the screw rod through the bevel gear and thus adjusting the height of the stool above the floor.
In accordance with another feature of the invention, th drum height adjusting means preferably comprises a pair of vertical racks provided on the opposite peripheral surfaces of the drum, a pair of shafts mounted to the floor adjacent respective vertical racks, a pinion connected to each shaft and engaged into each respective vertical rack, a crossed belt operatively connected between the two shafts and a driving mechanism adapted to rotate one of the shafts in one direction and which rotates the other shaft in the opposite direction through the crossed belt to raise or lower the stool above the floor. The driving mechanism may further include a first pulley connected to one of the shafts, a second pulley mounted for rotation at a position adjacent the stool, a hand wheel connected to the second pulley and an open belt wrapped about the first and second pulleys so that the stool may be raised and lowered by rotating the hand wheel which in turn rotates the two shafts with their pinions engaged to the respective vertical racks on the drum.
According to a further aspect of the present invention, the above drum is an inner cylinder of the enclosed double-walled type which is closely fitted into an outer cylinder of similar construction provided under the floor. The inner and outer cylinders are filled with oil and movable in relationship to each other by hydraulic valving means.
In another embodiment of the invention, an inner cylinder is vertically movable within an outer cylinder which is provided under the floor. The inner cylinder includes the stool which can be positioned at a desired height above the floor. The outer cylinder includes a peripheral flange extending outwardly from the upper edge of the cylinder and aligned over the border of the hole in the floor. In this way, the outer cylinder is supported at its upper edge in the vicinity of the hole and extends vertically downwardly from the level of the floor. The outer cylinder can be fixed to the floor by suitable means, such as, screws or bolts connected to the flange into the floor. Either the inner or the outer cylinder may include a pair of longitudinal slots or elongated holes on opposite sides thereof which are provided with internal substantially vertical racks of identical pitch.
A pair of pinions are mounted on a rotatable horizontal shaft and they are adapted to mesh with the internal racks of the slots. The pinions and horizontal shafts may be provided either in the outer or inner cylinder which does not include the elongated slots. A driving mechanism for rotating the pinions can be provided which includes a manual hand wheel connected to a vertical shaft running alongside the vertical cylinders and ending in a bevel gear which is engaged with a bevel gear connected to one end of the horizontal shaft.
In yet another embodiment of the invention, the drum may comprise an air cylinder with an air supply or compressor and an air-extracting vacuum pump connected thereto for providing the vertical movement of the stool. In this embodiment, a plurality of stools may be operated independently from one another by the use of a set or single compressor and vacuum pump connected thereto.
In a still further embodiment of the invention, at least one pair of base rods are slidably mounted at an angle in the floor adjacent opposite sides of the stool. The stool includes a seat having two facing arcuate portions which are slidably mounted on the upper surface of the stool. Each arcuate portion is connected to at least one base rod on respective sides of the stool and the spacing between the arcuate portions is adjusted with the raising or lowering of the stool to provide a seat of varying width complementing the height of the stool.
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 uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a partially in section side view of a water closet constructed in accordance with the invention;
FIG. 2 is a partial sectional side view of another embodiment of the invention;
FIG. 3 is a perspective explanatory view of the operation of the embodiment shown in FIG. 2;
FIG. 4 is a partial sectional side view of another embodiment of the invention;
FIG. 5 is a partial sectional view of the water closet shown in FIG. 4;
FIG. 6 is a partial sectional side view of a still further embodiment of the invention;
FIG. 7 is a partial sectional rear elevational view of the water closet shown in FIG. 6;
FIG. 8 is a partial sectional side view of a water closet according to another embodiment of the invention;
FIG. 9 is a partial sectional rear elevational view of the water closet shown in FIG. 8;
FIG. 10 is a partial sectional elevational view of the water closet according to another embodiment of the invention;
FIG. 11 is a partial sectional side view of the water closet shown in FIG. 10.
FIG. 12 is a two-positioned plan view of the water closet shown in FIG. 10; and
FIG. 13 is a schematic piping diagram of a water closet contructed in accordance with another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be hereinafter described with similar numerals designating similar parts.
With reference to FIG. 1, a toilet for human waste, generally designated 60, has a floor or support member 1 provided with a hole or guide opening 2. A stool member, generally designated 70, includes a stool or seat portion 3, which is equipped with a heater 3'. The stool member 70 includes a drum or tubular member 6 for vertical movement in the hole 2. A flexible flush pipe 4' extends from a water tank 4 to a water inlet 4a of the stool 3 to form a water tank connection to the stool member. A bellows-type scupper pipe 5 is connected to a scupper of the stool 3 and forms part of an opening through which waste may pass. The drum 6 extends vertically from the bottom of the stool 3 and is integral therewith. A mounting means for the stool member 70 includes two pairs of guide wheels 7 provided under floor 1 along the edge of hole 2 so that they bear against and laterally support the drum 6 at channels 6e to facilitate the smooth vertical movement of stool 3. A drive means 80 for moving the stool member 70 upwardly and downwardly includes a vertically rotatable screw rod or spindle 8 which is provided alongside of stool 3. Screw rod 8 is supported by a rotating means at its upper end by floor 1 through a stay 9 and a bearing 10 and, at its lower end, by a stand 12 through a bearing 11. The rotary screw rod 8 is threaded into a nut 13 which is fixed to the rear end of the stool 3. A bevel gear 14 is connected near the bottom of rotating screw rod 8. Bevel gear 14 is engaged with a bevel gear 18 and is rotated by a motor 16 through a reduction gear 17. The operation of motor 16 is controlled by a switch 15 which can be disposed near the stool 3. Stool 3 is adjusted to a desired level or height by operating the switch 15 to rotate the motor 16, reduction gear 17, bevel gears 18 and 14 and rotating screw rod 8 either clockwise or counterclockwise.
Another embodiment of the present invention is shown in FIGS. 2 and 3. Referring to these Figures, the toilet has a floor or support member 1 with a hole 2 therein, over which a stool 3 with a heater 3' is vertically movable. A flush pipe 4' extends from a water tank 4 to the water inlet of the stool 3. A bellows-type scupper pipe 5 is connected to the scupper of the stool 3. A vertical drum 6 is connected to the bottom of stool 3 and forms an integral part thereof. A pair of guide wheels 7a and 7a' are provided under floor 1 along the edge of the hole 2 so that they bear against and laterally support drum 6 to facilitate the smooth vertical movement of stool 3. A pair of racks 19 and 19' are provided along vertical sides of the drum 6 and mesh with pinions 20 and 20', respectively. Pinions 20 and 20' are connected to a crossed-belt means which includes a pair of shafts 21 and 21'. Shafts 21 and 21' are operatively connected to each other by crossed-belt and pulley arrangement 22 in order to reverse the rotational direction of one shaft with respect to the other. An open belt device 23 which is rotated by a manual hand wheel 24 is fixed to shaft 21.
In operation, stool 3 is adjusted to a desired level or height by rotating the manual hand wheel 24 which in turn rotates the shaft 21 through belt 23. Pinion 20 then acts on rack 19 and pinion 20', through belt 22, acts on rack 19' to raise or lower drum 6 and stool 3.
Another embodiment of the present invention is described with reference to FIGS. 4 and 5. In FIGS. 4 and 5, the toilet includes a floor 1 with a hole 2. Mounting means 90 include a double-walled drum 6a which has an inner wall 6a' forming an inner space 61 in the center of drum 6a through which a scupper pipe 5a is passed. Double-walled drum 6a forms an inner cylinder and is provided vertically at the bottom of stool 3 integrally therewith. A double-walled drum 6b with an open top and closed bottom has an inner wall 6b' similar to the above-mentioned inner wall 6a' and it is provided on an under-the-floor platform 25. Drum 6b acts as an outer cylinder for receiving the double-walled drum 6a. The inner double-walled drum 6a is vertically movable and closely fitted in the outer double-walled drum 6b. The outer and inner double-walled drums 6b and 6a are filled with oil 26 having a selected viscosity. The bottom wall of the inner double-walled drum 6a has an oil passage 27 open to the inside of the outer double-walled drum 6b.
A valve ball 29 is provided in the oil passage 27 which opens and closes the passage 27 by the action of a lever 28. A pair of screw rods 8a and 8a' are provided at the front and rear sides of the inner double-walled drum 6a, which are rotated by a rotary handle or hand wheel 30 and are synchronized by a chain gearing means 31. Screw rods 8a and 8a' are threaded into nut sections 13a and 13a' which are fixed to the upper parts of the front and rear sides of the outer double-walled drum 6b, respectively.
Reference numerals 32 and 32' designate biasing means or springs for supporting the weight of the inner double-walled drum 6a, thereby, negating the weight of drum 6a on the screw rods 8a and 8a'. 33 designates a link for connecting lever 28 to a valve ball 29. 34 designates a spring for restoring the valve ball 29 to the closed position and for restoring the lever 28 to the non-operational position. A cover 35, having a guide groove 37, with stop notches 36 and 36' is disposed over the linkage to lever 28. A chain 38 is engaged with sprockets 39 and 39' disposed on opposite lateral ends of the stool 3. A passage 40 is provided through the inner double-walled drum 6a to allow the passage of the chain 38. A water inlet 41 is provided and a scupper pipe 5a extends through a scupper 5a'. Numeral 42 designates a cover for screw rods 8a and 8a'.
In operation, when the top surface of stool 3 is to be lowered, lever 28 is tilted clockwise, as seen in FIG. 4, to move link 33 and ball 29 downwardly. Lever 28 can be engaged into notches 36 and 36' alternatively, thereby, bringing valve ball 29 into the open position. Oil 26 from the outer and inner double-walled drums 6b and 6a can thus flow from one drum to the other through the oil passage 27. If rotary handle 30 is then rotated, and screw rods 8a and 8a' are synchronously rotated through the chain gearing 31. The bottom parts of screw rods 8a and 8a' are consequently threaded downwardly through nut sections 13a and 13a', respectively, and thereby, the inner double-walled drum 6a is lowered.
When the top surface of stool 3 is lowered to a desired level, lever 28 is disengaged from the stop notch 36 or 36' and, thereby, lever 28, link 33 and valve ball 29 are returned to the original positions by the action of spring 34 and, as a result, oil passage 27 resumes the closed state. On the other hand, when the top surface of stool 3 is to be lifted, lever 28 is tilted in the same manner as mentioned above to bring valve ball 29 into the open state. It thus becomes possible to move oil 26 from inner double-walled drum 6a to outer double-walled drum 6b. If the rotary handle is then rotated, the screw rods 8a and 8a' will elevate inner double-walled drum 6a. When the top surface of stool 3 thus reaches the desired level, lever 28 is disengaged from stop notches 36 or 36' in the same manner as mentioned above to close oil passage 27.
The embodiment of the present invention will now be described with reference to FIGS. 6 and 7. The water closet or toilet of FIGS. 6 and 7 has a floor or support member 1 with a hole 2. A drum 6d forms a part of the support member, and acts as an outer cylinder or tubular member, having an outwardly extending flange 43 formed integrally with the upper edge thereof. The outer drum 6d is fitted in hole 2 from above, and is fixed to floor 1 by fastening flange 43 to floor 1 around the periphery of hole 2 from above. A drum or tubular portion 6c, which acts as an inner cylinder and is a part of the stool member, includes the integrally formed stool or seat portion 3. Inner drum 6c is vertically movable in outer drum 6d. Stool 3 has, at its periphery, an outwardly extending flange 44 integrally formed therewith and adapted to engage with the top edge of the outer drum 6d.
On its opposite sidewalls, outer drum 6d has longitudinally extending elongated holes or slots 45 and 45' which have internal racks 19a and 19a' of the same pitch, along on side edge thereof. A horizontal shaft 46 is rotatably supported near the bottom of the opposite sidewalls of inner drum 6c, and both ends of shaft 46 extend through elongated holes or slots 45 and 45', respectively. Pinions 20a and 20a' mesh with respective racks 19a and 19a' and are connected to the projected ends of horizontal shaft 46. Horizontal shaft 46 includes an extension 46' at its one end to which a bevel gear 47 is fixed.
A vertical shaft 48 is rotatably and vertically movably mounted on the floor in the vicinity of hole 2. Vertical shaft 48 is provided with a bevel gear 49 adjacent the bottom end thereof. Bevel gear 49 meshes with bevel gear 47 and shaft 48 and includes a hand wheel 30a attached adjacent the top thereof. The stool 3 may thus be vertically moved by rotating the hand wheel clockwise or counterclockwise.
Another embodiment of the invention is described with reference to FIGS. 8 and 9. In the embodiment shown in FIGS. 8 and 9, inner drum 6c and outer drum 6d are provided in the same manner as shown in the embodiment of FIGS. 6 and 7. Inner drum 6c has longitudinal elongated holes or slots 45 and 45' on its opposite sidewalls, which have racks 19a and 19a' of the same pitch at one interior edge thereof. A horizontal shaft 46 is inserted through elongated holes 45 and 45'. Both ends of horizontal shaft 46 are rotatably supported adjacent the bottom of opposite sidewalls of outer drum 6d. Pinions 20 and 20a' are provided to engage racks 19a and 19a', respectively. Pinions 20a and 20a' are fixed to horizontal shaft 46 at appropriate locations. Horizontal shaft 46 includes an extension 46' at one end thereof which is coupled to a motor 50. The height of the stool 3 may be changed by rotating motor 50 clockwise or counterclockwise by suitable controls, which have not been shown.
Another embodiment of the invention is described as follows with reference to FIGS. 10 to 12. In this embodiment, the width of the seat on the stool can be changed by an interlocking means to the above-mentioned stool height-adjusting means. The stool height-adjusting means is formed in the same manner as in the case of the embodiment shown in FIGS. 8 and 9.
Two pair of short guide pipes 51 and 51' are fixed in floor 1 at respective sides of stool 3 so that they are inclined slightly outwardly from a vertical line. Two pair of base rods 52 and 52' are slidably mounted in the short pipes 51 and 51', respectively, so that they may be moved along the axis of short pipes 51 and 51'. A set of two arc-shaped closet seat members or arcuate portions 53 and 53' are laterally slidable on stool 3. Closet seat members 53 and 53' are fixed to the top ends of base rods 52 and 52', respectively. In operation, the height of the stool or closet seat is changed when motor 50 is rotated clockwise or counterclockwise. When the height of the stool is increased, base rods 52 and 52' are moved while guided by short pipes 51 and 51', and therefore, the width of the closet seat comprising members 53 and 53' are gradually increased. On the other hand, the width of the closet seat is gradually decreased when the stool is lowered. An adult can therefore use the water closet while keeping the stool 3 high, and thus the closet seat wide and, similarly, a child can use the water closet while maintaning a low height of stool 3 and thus the closet seat narrow. Thus, besides the height of stool 3, the width of closet seat 53 and 53' may also be easily adjusted by actuating motor 50.
A still further embodiment of the present invention is described with reference to FIG. 13. In the embodiment of FIG. 13, a plurality of stools in water closets are provided in a multi-storied building or the like, and they may be individually adjusted in height. In FIG. 13, a plurality of stools 3 are vertically movably provided on the floor 1 of each story in the same manner as in the case of the embodiments mentioned hereinbefore. An air cylinder 6e, which corresponds to the drum in each of the embodiments of FIGS. 1 through 12, is fixed to each stool 3 so as to vertically move the stool. A compressor 54 is provided to supply air to the air cylinder 6e and a vacuum pump 55 is provided for extracting air from air cylinder 6e. In addition, a manual cock 56 is provided in the vicinity of each stool 3 in order to achieve the switchover from the air supply operation to the air extracting operation, or vice versa. Each stool 3 may thus be independently elevated or lowered by controlling the manual cock 56.
In accordance with the present invention, a hydraulic cylinder and pump arrangement may be substituted for the air cylinder arrangement described above, and further may be substituted for the various drive means hereinbefore described.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A water closet, comprising a floor, a movable stool disposed above the floor and mounted for vertical displacement above the floor and a drive apparatus connected to the stool for moving the stool to a selected height above the floor. The drive apparatus may include a drum connected to the stool and vertically movable in a hole in the floor. The stool may further be provided with a seat having two facing arcuate portions slidable on the stool and a pair of base rods connected to each arcuate portion extending at an angle downwardly toward the floor and through respective guides so as to adjust the spacing between the arcuate portions and resulting width of the seat with the vertical movement of the stool above the floor. | 4 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims priority from and is related to U.S. Provisional Patent Application Ser. No. 61/974,464, filed 3 Apr. 2014, this U.S. Provisional Patent Application incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
[0002] The present invention generally relates to rotating electromechanical systems and specifically to computerized means for protecting rotating electromechanical systems against damages caused by mechanical overload.
BACKGROUND
[0003] A common practice in the design and construction of rotating electromechanical systems is the use of mechanical coupling devices.
[0004] A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment.
[0005] Shaft couplings are used in machinery for several purposes, the most common of which are the following:
To provide for the connection of shafts of units that are manufactured separately such as a motor (motor and gear input, gear output and load) and to provide for disconnection for repairs or alterations. To provide for misalignment of the shafts or to introduce mechanical flexibility. To reduce the transmission of shock loads from one shaft to another. To alter the vibration characteristics of rotating units.
[0010] Mechanical overload may damage or interrupt the system operation.
[0011] The consequences of undetected overload in mechanical systems can be grave. Countless systems suffer overload damages at all times. Overload can occur abruptly (for example some object falling into the rotating area) or build up gradually over many months of operation without being noticed.
[0012] When overload failure occurs damages can manifest in many different ways such as local system breakage, production lines stalled for many hours or days, fire hazard etc. Economical impact may be very substantial.
[0013] Couplings do not normally allow disconnection of shafts during operation, however there are specialized torque limiting couplings which can slip or disconnect when some torque limit is exceeded. State of the art protected couplings have some disadvantages:
A slipping coupling may slip for a very long time without being noticed. When slipping is detected maintenance people often tend to just tighten the adjustment screws as a quick fix, overriding intended protection level, therefore making this protection useless. Disconnecting (mechanical fuse) type protection forces the replacement of the coupling unit device upon failure on top of expenses associated with fixing the major cause of overload.
SUMMARY
[0017] According to a first aspect of the present invention there is provided a system for protecting rotating electromechanical systems against damages, comprising:
a coupling configured to connect a moment provider with a load, comprising:
first communication means; first CPU; first energy providing means; and at least one sensor;
a control unit comprising:
second communication means; second energy providing means; and second CPU;
[0027] said coupling configured to use said at least one sensor for performing measurements and to communicate with said control unit.
[0028] The first energy providing means may comprise an integrated generator.
[0029] The first energy providing means may comprise a battery.
[0030] The control unit may additionally comprise a switch configured to switch off or on said moment provider's power.
[0031] The coupling may additionally comprise first input means.
[0032] The control unit may additionally comprise second input means.
[0033] The first input means may comprise at least one of keyboard, computer mouse and a laptop.
[0034] The second input means may comprise at least one of keyboard, computer mouse and a laptop.
[0035] The coupling may additionally comprise a display connected with said first CPU.
[0036] The control unit may additionally comprise a display connected with said second CPU.
[0037] The at least one sensor may comprise at least one of torque sensor, vibration sensor, speed sensor, inertial sensor, hall effect sensor, temperature sensor, spin direction sensor and a microphone.
[0038] The control unit may additionally comprise at least one sensor.
[0039] The at least one sensor may comprises at least one of a temperature sensor, vibration sensor and a microphone.
[0040] The first and second communication means may comprise at least one of wireless and wired communication.
[0041] The second energy providing means may comprise a power supply.
[0042] The second energy providing means may comprise a battery.
[0043] According to a second aspect of the present invention there is provided a coupling configured to connect a moment provider with a load, comprising:
a CPU; energy providing means; and at least one sensor;
[0047] said coupling configured to sample measurements from said at least one sensor.
[0048] The coupling may additionally configured to save said samples.
[0049] The at least one sensor may comprise at least one of torque sensor, vibration sensor, speed sensor, inertial sensor, hall effect sensor, temperature sensor, spin direction sensor and a microphone.
[0050] The energy providing means may comprise an integrated generator.
[0051] The energy providing means may comprise a battery.
[0052] The coupling may additionally comprise communication means.
[0053] The communication means may comprise at least one of wireless and wired communication.
[0054] The coupling may additionally comprise input means.
[0055] The input means may comprise at least one of keyboard, computer mouse and a laptop.
[0056] The coupling may additionally comprise a display connected with said CPU.
[0057] According to a third aspect of the present invention there is provided a control unit configured to communicate with a moment provider, comprising:
a CPU; at least one sensor; energy providing means; and a cutoff switch configured to cut said moment provider power;
[0062] said control unit configured to sample measurements from said at least one sensor.
[0063] The control unit may additionally be configured to save said samples.
[0064] The at least one sensor may comprise at least one of a temperature sensor, a vibration sensor and a microphone.
[0065] The control unit may additionally comprise input means.
[0066] The input means may comprise at least one of keyboard, computer mouse and a laptop.
[0067] The control unit may additionally comprise a display connected with said CPU.
[0068] The control unit may additionally comprise communication means.
[0069] The communication means may comprise at least one of wireless and wired communication.
[0070] The energy providing means may comprise a power supply.
[0071] The energy providing means may comprise a battery.
[0072] According to a fourth aspect of the present invention there is provided a method of protecting rotating electromechanical systems against damages, comprising:
sampling by a remote device inputs from a moment provider; comparing said inputs to pre-determined thresholds; continuously broadcasting messages to a control unit, said messages indicating the remote device's status and the comparison results; analyzing said messages by the control unit; and determining whether to cutoff said moment provider's power according to said analysis.
[0078] The method may additionally comprise generating power by a generator.
[0079] The method may additionally comprise receiving by at least one of said control unit and said remote device at least one operating parameter.
[0080] The method may additionally comprise sending by at least one of said control unit and said remote device at least one notification relating to operational measurements.
[0081] The method may additionally comprise displaying at least one of event log, notification log and event graph.
BRIEF DESCRIPTION OF THE DRAWINGS
[0082] For better understanding of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings.
[0083] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the accompanying drawings:
[0084] FIG. 1A is a schematic drawing showing system components for carrying out the present invention;
[0085] FIG. 1B is a block diagram showing the system components for carrying out the present invention;
[0086] FIG. 2A is a schematic view of an exemplary rotary mechanical coupling according to the present invention;
[0087] FIG. 2B is a schematic view of section C-C of FIG. 2A ;
[0088] FIG. 2C is an integrated generator's disk;
[0089] FIG. 3 shows an exemplary rotary mechanical coupling according to the present invention;
[0090] FIG. 4 shows an exemplary control unit according to the present invention;
[0091] FIG. 5 is a schematic drawing showing the system communication;
[0092] FIG. 6 is an exemplary graph representing monitoring in the time domain;
[0093] FIG. 7 is an exemplary graph representing monitoring in the frequency domain;
[0094] FIG. 8 is an exemplary events log;
[0095] FIG. 9 is an exemplary notification log;
[0096] FIG. 10 is a flowchart showing the process performed by the control unit according to the present invention; and
[0097] FIG. 11 is a flowchart showing the process performed by the remote device according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0098] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
[0099] A common practice in the design and construction of rotating electromechanical systems is the use of mechanical coupling devices.
[0100] A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment.
[0101] The present invention aims to provide means for protecting electromechanical systems against damages caused by mechanical overload.
[0102] In the following description:
[0103] Rotary mechanical coupling refers to remote device.
[0104] FIG. 1A is a schematic drawing showing a system 100 components, comprising: a control unit 140 connected or adjacent to a moment provider 140 A such as a motor, a rotating device 110 A such as a pump, compressor, etc. and a rotary mechanical coupling 110 (remote device) that connects the moment provider 140 A with the rotating device 110 A.
[0105] According to embodiments of the present invention, a power or moment transmitting shaft may be connected between the moment provider 140 A and the rotary mechanical coupling 110 , or between the rotary mechanical coupling 110 and the rotating device 110 A.
[0106] FIG. 1B is a block diagram showing the system components for carrying out the present invention.
[0107] The system 100 A comprises two parts:
1. A rotary mechanical coupling 110 , comprising: an embedded torque (moment) gage 115 , an electronic module (CPU circuit) 120 , a wireless connection 125 and an integrated generator 130 . 2. A control unit 140 comprising: an electronic module 145 , a wireless connection 150 , a cutoff switch 155 and input/output means 160 .
[0110] The electronic module 120 informs the control unit 140 , via wireless connection 125 , when a pre-programmed torque threshold has been exceeded (fault condition).
[0111] The electronic module 145 may decide to disconnect the moment provider's electrical power in the event of mechanical overload measured by the coupling 110 . When the mechanical load exceeds a pre-determined threshold, the moment provider's electrical power is cutoff by a cutoff switch 155 .
[0112] The integrated generator 130 is the power source of the electronic module 120 , which utilizes system rotation to harvest its low required energy consumption. The generator comprises magnets ( 245 of FIG. 2B ) and inductors ( 250 of FIG. 2B ). While the rotary mechanical coupling 110 is rotating, the electrical energy that is created is collected and used as the power source of the electronic module 120 . The integrated generator has a charge time close to real time which makes it reliable. In case of a generator's operation failure, the control unit 140 cuts the moment provider's power supply and may issue an alert, thus preventing any possible damage.
[0113] FIG. 2A is a schematic view of an exemplary rotary mechanical coupling 110 according to embodiments of the present invention, comprising: a user connection 205 and a moment provider connection 230 .
[0114] FIG. 2B is a schematic view of section C-C of FIG. 2A , comprising: a torsion axis 235 , a power supply circuit disk (integrated generator disk) 240 , magnets 245 , inductors 250 , a CPU circuit (electronic module) 120 and a strain gauge 255 .
[0115] The coupling 110 is configured to join two pieces of rotating equipment while permitting some degree of misalignment, furthermore, it comprises a torque measurement system. The torque measurement system measures the torque using an electrical circuit that measures the resistance, such as, for example, Wheatstone bridge. The resistors value changes depending on the mechanical deformation of the torsion axis.
[0116] According to embodiments of the present invention, the torque measurement system may measure the torque by any torque measurement method known in the art and is not limited to the one described hereinabove.
[0117] The electronic module 120 measures operational parameters such as torque and optionally speed, spin direction, vibrations, sound, temperature, etc. and transmits the measured values to the control unit 140 . The control unit receives the measurements transmission(s) and may comprise additional sensors such as a temperature sensor and a microphone, for noise measurements, which enables it to perform additional tests.
[0118] The measurements may be saved both in the rotary mechanical coupling 110 and in the control unit 140 .
[0119] FIG. 2C demonstrates the integrated generator disk 240 with the connection 270 that is configured to ensure fixation of the disk while the rotary mechanical coupling 110 is rotating.
[0120] FIG. 3 shows an exemplary rotary mechanical coupling 110 according to embodiments of the present invention, comprising:
Generator 305 —a module equipped with coils and rectification circuits used for utilizing device rotation for generating electrical power for powering coupling device electronics. The generator may be mechanically and electrically connected to the main coupling device electronic module 120 . Chargeable Battery 310 —enables powering full functional operation of the coupling device in the first seconds after power down till generator power is fully available. Battery Charger IC 315 —and supporting electronics for recharging the chargeable battery when generator power is available for future use. Vin Selector 320 —selects the power source—generator if available, battery otherwise. Super Capacitor 325 —stores generator energy for coupling device's operation on main voltage bus. LDO (Low Dropout Voltage regulator) 330 —regulates voltage bus and produces all low DC voltages required by the various components. Torque Gage 335 —one or few strain gage stickers bonded to the coupling device's mechanical structure—measures real-time torque value between coupling input and output. AMP 340 —an analog amplifier that amplifies low voltage received from the strain gage. ADC (Analog to Digital Converter) 345 —an analog to digital conversion module equipped with an analog switch. Used for translating real-time analog voltage levels into digital values that can be processed by the CPU. Sensors 350 —various additional and optional analog or digital output sensors devices such as inertial, temperature, hall effect, encoders and the like. CPU 355 —controls, monitors, coordinates and supervises all coupling device's chips and operation. Radio 360 —transmits and receives data between the coupling's CPU 355 and the control unit's CPU 435 ( FIG. 4 ).
[0133] FIG. 4 shows an exemplary control unit 140 according to embodiments of the present invention, comprising:
Motor in 405 —single or multiphase motor voltage enters the control unit from the system's electrical cabinet. The power required for operation of the control unit is taken from the motor voltage or optionally directly supplied from the electrical cabinet. Power Supply 410 —converts AC motor voltage into DC low voltage to supply control unit requirements. DC Selector 415 —selects power source for the unit—direct DC supply if available or power supply output. LDO (Low Dropout Voltage Regulator) 420 —regulates voltage bus and produces all low DC voltages required by the various components. M 425 —system motor or actuator connects to the protected rotating mechanical system that is mechanically attached to the coupling device. Relay 430 —switches motor ON or OFF by CPU control (cutoff switch). CPU 435 —controls, monitors coordinates and supervises control unit's chips, communication devices and operation system. Communication Chips—various communication chips enable connection to Ethernet LAN, Internet and Cellular networks by wired and wireless communication links. The various communication chips are controlled and operated by the CPU: USB to UART 445 —enables direct USB link to computer, laptop, tablets, smart phones and the like. LAN Module 450 —enables wired Ethernet LAN link. Wi-Fi Module 455 —enables wireless Ethernet LAN link. Cellular Modem 460 —enables wireless communication to cellular networks. Radio 465 —communicates CPU 435 to CPU 355 . Receives data, fault alarms and notifications from the coupling. Transmits configuration data and handshakes with coupling radio. Sensors 470 —various additional analog or digital output sensors such as temperature sensors can be monitored in real-time.
[0148] FIG. 5 is a schematic drawing showing the system 100 A communication.
[0149] The control unit 140 may be connected to a laptop 510 , PC 520 , tablet 530 , smart phone 540 , etc. via wired or wireless connection in order to receive operating parameters such as torque limit, send notifications and diagnostics about the system behavior that inform of a problem in real time, provide a periodic report by day, week, month, etc., event logs, graphs, etc. to a control center, a mechanical support technician, etc. The control unit 140 and the rotary mechanical coupling 110 are connected via wireless connection:
The rotary mechanical coupling 110 may receive the torque limit input value from the control unit 140 . The control unit 140 receives a notification from the rotary mechanical coupling 110 when a torque threshold is exceeded. The control unit 140 receives measurements of: torque and optionally speed, spin direction, vibrations, etc. from the rotary mechanical coupling 110 .
[0153] Operating parameters such as torque limit may be pre-programmed manually by a technician using a laptop, tablet, smart phone, etc. via wired or wireless connection with the control unit 140 .
[0154] According to embodiments of the invention, the rotary mechanical coupling 110 or the control unit 140 may collect torque measurements for a pre defined time, calculate the average torque and set it as the torque limit.
[0155] The rotary mechanical coupling 110 may also allow a torque range and not only a single value. The torque range prevents cases of moment provider's disconnection due to momentary overload, moreover, the torque range may enable the control unit 140 to send notifications in different levels of importance and urgency to the control center or the mechanical support technician and thus anticipate system failure. For example, if the control center or the mechanical support technician gets frequent notifications about measured torques near the torque range's upper limit, they may conclude that at least one of the elements of the system is about to fail.
[0156] Notifications and diagnostics may be sent by the control unit 140 as mentioned above and may also be saved as a log and/or graphs in the control unit or in internet cloud services etc. to be derived later.
[0157] The control unit 140 monitors the system behavior. Monitoring may be done in several ways.
[0158] FIG. 6 is an exemplary graph representing monitoring in the time domain. For each day the control unit may monitor the torque, speed, vibration, noise, temperature, etc. and display them in a graph (some of the data may be received from the rotary mechanical coupling 110 ).
[0159] FIG. 7 is an exemplary graph representing monitoring in the frequency domain. For each frequency the control unit may monitor the torque, vibration, noise, speed, etc. and display them in a graph (some of the data may be received from the rotary mechanical coupling 110 ).
[0160] For each graph the user may choose to view the real time data or the history data that has been saved in the system. The user may also choose to add a filter on the graph in order to observe specific characteristics. He may also choose to save or export the data that has been collected.
[0161] FIG. 8 is an exemplary events log according to embodiments of the invention. For each event the log may save the date and hour, device type, device UID, event, value and event details for a periodic monitoring.
[0162] Each device ( 110 and 140 ) has a unique UID in order to ensure that the electronic module 120 communicates only with its specific control unit 140 and not other system's unit.
[0163] The events log may be shared, saved, printed, etc. for various uses.
[0164] FIG. 9 is an exemplary notification log according to embodiments of the invention. The control unit 140 may send the notifications as mentioned above by voice, SMS, E-Mail, messaging applications (such as WhatsApp), etc.
[0165] According to embodiments of the present invention, a number of systems may be connected in hierarchical order. For example, if a number of moment providers are connected in a row and the first moment provider ceases to work the system may stop all the other moment providers as well in order to prevent overload.
[0166] FIG. 10 is a flowchart showing the process performed by the control unit 140 according to embodiments of the present invention.
[0167] The process starts in step 1005 as soon as the moment provider's (the motor in this embodiment) power is turned on. In step 1010 the control unit 140 is initialized and in step 1015 the motor relay (cutoff switch) is turned on. The relay enables/disables the moment provider's operation as mentioned above. In step 1020 the unit resets the “sign of life” timer. The “sign of life” is a sign that the remote device is working. In step 1025 the unit checks if a “sign of life” message has been received from the remote device 110 . If it hasn't, the unit checks in step 1030 if the “sign of life” timer is timed out. If it isn't, the process goes back to step 1025 ; if it is, it means that there is a problem with the remote device 110 and the relay (cutoff switch) is turned off (step 1035 ) to prevent any possible damage. In step 1040 the unit may issue a notification according to predefined specifications (optional) and in step 1045 it waits for restart. If in step 1025 a “sign of life” message has been received, the unit continues to step 1050 and checks if a “trip motor” message has been received. The “trip motor” message indicates a problem detected by the remote device (such as overload). If the “trip motor” message has been received, the unit continues to steps 1035 , 1040 and 1045 . If it hasn't, the unit checks in step 1055 if a notification is required, according to predefined specifications, if it isn't, the process goes back to step 1020 ; if it is, the unit issues a notification in step 1060 and goes back to step 1020 .
[0168] FIG. 11 is a flowchart showing the process performed by the remote device according to embodiments of the present invention.
[0169] The process starts in step 1105 as soon as the generator starts to work. In step 1110 the remote device is initialized and in step 1115 the device starts to sample inputs. In step 1120 the device constructs a “sign of life” message and checks, in step 1125 , if a trip notification is required according to the inputs. If it is, the device adds a “trip motor” message to the “sign of life” message in step 1130 and broadcasts the “sign of life” message in step 1135 . If it isn't, the process continues directly to step 1135 and broadcasts the “sign of life” message. In step 1140 the device goes to “sleep” for X milliseconds in order to save energy and “wakes up” in step 1145 . The “sleep” time enables the system to save energy in cases where the harvested voltage is low. As soon as the process “wakes up” it goes back to step 1115 .
[0170] It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the essential attributes thereof, and it is therefore desired that the present embodiments and examples be considered in all respects as illustrative and not restrictive. Further, it is understood that certain features of specific aspects of the invention could be combined with specific features detailed in other aspects of the invention, so that any embodiment of the invention could include one or all of the features disclosed herein. | This invention relates to a system for protecting rotating electromechanical systems against damages including a coupling configured to connect a moment provider with a load, having first communication means, a first CPU, a first energy providing means and at least one sensor, a control unit having second communication means, second energy providing means, and second CPU, the coupling configured to use the at least one sensor for performing measurements and to communicate with the control unit. | 6 |
[0001] This application claims priority to U.S. Provisional Application No. 61/109,154, filed Oct. 28, 2008; the content of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] An electrophoretic display (EPD) is a non-emissive device based on the electrophoresis phenomenon influencing charged pigment particles suspended in a solvent. An EPD typically comprises a pair of electrodes, with at least one of the electrodes, typically on the viewing side, being transparent. An electrophoretic fluid composed of a colored dielectric solvent and charged pigment particles dispersed therein is enclosed between the two electrodes.
[0003] An improved EPD technology and a roll-to-roll manufacturing process are disclosed in U.S. Pat. No. 6,930,818, the content of which is incorporated herein by reference in its entirety.
[0004] For full color displays with the normal up/down switching mode, color filters overlaid on the viewing side of the display may be used. However, poor whiteness and lack of a high quality “black” state are the major problems for reflective color displays using color filters.
[0005] Therefore, there is still a need for an improved EPD with high quality full color capability that can also be manufactured in an efficient manner, particularly by a roll-to-roll manufacturing process.
SUMMARY OF THE INVENTION
[0006] The present invention provides novel display structures.
[0007] The first aspect of the invention is directed to a display device comprising a plurality of display cells wherein the display cells are separated by slanted partition walls. In one embodiment, the display cells are filled with an electrophoretic display fluid comprising charged pigment particles dispersed in a dielectric solvent or solvent mixture. In one embodiment, the electrophoretic display fluid comprises one type of charged pigment particles. In one embodiment, the electrophoretic display fluid comprises two types of charged pigment particles. In one embodiment, the partition walls are of a dark opaque color. In one embodiment, the partition walls are formed from a composition comprising air pockets or a filler material. In one embodiment, the filler material is non-conductive carbon black, pigment black, silica, ZnO, TiO 2 , BaSO 4 , CaCO 3 or polymer particles. In one embodiment, the display is capable of displaying the color of the charged pigment particles, the color of the solvent or solvent mixture, or the color of a background layer. In one embodiment, the color of the background layer is black. In one embodiment, the display is capable of displaying a binary color system. In one embodiment, the slanted partition walls have an angle in the range of about 25° to about 80°. In one embodiment, the total active area is at least about 50% of the total area of the viewing surface.
[0008] The second aspect of the present invention is directed to a display device comprising a plurality of display cells wherein the display cells are separated by indented partition walls having indented areas. In one embodiment, the display cells are filled with an electrophoretic display fluid comprising charged pigment particles dispersed in a dielectric solvent or solvent mixture. In one embodiment, the electrophoretic display fluid comprises one type of charged pigment particles. In one embodiment, the electrophoretic display fluid comprises two types of charged pigment particles.
[0009] In one embodiment, the indented partition walls do not have open passageways. In one embodiment, each display cell comprises one or more indented partition walls. In one embodiment, the display is capable of displaying the color of the charged pigment particles, the color of the solvent or solvent mixture, or the color of a background layer. In one embodiment, the thickness of the indented area is about 5% to about 80% of the total thickness of the partition wall. In one embodiment, the height of the indented area is about 5% to about 80% of the height of the partition wall. In one embodiment, the indented areas are of a rectangular shape. In one embodiment, the indented areas are of a rectangular shape with an arched top.
[0010] In one embodiment, the indented partition walls are open partition walls having open areas. In one embodiment, the ceiling of the open areas is painted black. In one embodiment, the open areas are of a rectangular shape. In one embodiment, the open areas are of a rectangular shape with an arched top. In one embodiment, the height of the open areas is about 5% to about 80% of the height of the partition wall. In one embodiment, the display is a striped color display. In one embodiment, the open partition walls randomly appear in the display.
[0011] The electrophoretic display structures of the present invention may be manufactured by a continuous or semi-continuous roll-to-roll manufacturing process. The structures are capable of providing enhanced color states.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] It is noted that all figures are shown as schematic and are not to scale.
[0013] FIG. 1 is a cross-section view of an electrophoretic display structure having slanted partition walls.
[0014] FIG. 2 is a cross-section view of an electrophoretic display capable of displaying multiple color states.
[0015] FIG. 3 shows the dimensions of an electrophoretic display having slanted partition walls.
[0016] FIGS. 4 a and 4 b are three-dimensional view of an electrophoretic display having indented partition walls.
[0017] FIG. 5 is a cross-section view of an electrophoretic display capable of displaying multiple color states.
[0018] FIGS. 6 a - 6 c show the top view of display structures and their corresponding electrode configurations.
[0019] FIG. 7 shows the dimensions of an electrophoretic display having indented partition walls.
[0020] FIGS. 8 a and 8 b are three-dimensional view of an electrophoretic display having open partition walls.
[0021] FIG. 9 is a cross-section view of an electrophoretic display capable of displaying multiple color states.
[0022] FIG. 10 is a top view of a striped color display device.
[0023] FIG. 11 is the cross-section view of an electrophoretic display having open partition walls.
[0024] FIG. 12 is a top view which illustrates how the display of FIG. 11 operates with increased contrast ratio.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The first aspect of the present invention is directed to an electrophoretic display structure ( 100 ) having trapezoid-shaped partition walls, as shown in FIG. 1 . The display cells (or microcups) ( 101 ) are separated by the trapezoid-shaped partition walls ( 102 ). The trapezoid-shaped partition walls may also be referred to as the slanted partition walls. The display cells are then filled with an electrophoretic fluid ( 104 ) and optionally sealed with a polymeric sealing layer ( 105 ).
[0026] It is preferable for the slanted partition walls to have an opaque color, especially a gray opaque color. This may be achieved by introducing air pockets or a filler material such as non-conductive carbon black, pigment black, silica, ZnO, TiO 2 , BaSO 4 , CaCO 3 or polymer particles, preferably non-conductive carbon black or pigment black, preferably in the amount of 0.01-20% by weight, more preferably in the amount of 0.01-10% by weight, into the composition for the formation of the display cells. Colored pigments may also be used to create special appearance.
[0027] FIG. 2 illustrates a full color display utilizing the structure of FIG. 1 . In FIG. 2 , the structure of FIG. 1 has been turned 180°. In other words, the side opposite of the sealing layer ( 105 ) is now the viewing side.
[0028] For illustration purpose, there are only three display cells shown. Each of the display cells is sandwiched between a first layer ( 106 ) and a second layer ( 107 ). The first layer ( 106 ) comprises a common electrode ( 108 ) (i.e., the ITO layer). The second layer ( 107 ) comprises a center electrode and at least one side electrode for each display cell. In FIG. 2 , there are two side electrodes ( 110 a and 110 b ) on each side of the center electrode ( 109 ) for each display cell. The center electrode and the side electrodes are not in contact with each other.
[0029] The common electrode ( 108 ) may be an entire piece of ITO layer spreading across the display cells.
[0030] There is a black background layer ( 111 ) which is above the second layer ( 107 ). It is also possible to have the black background layer underneath the second layer or the second layer may itself serve as a black background layer.
[0031] Typically, the display cells are filled with a display fluid comprising a colored (e.g., red, green or blue) dielectric solvent or solvent mixture with white particles dispersed therein. The charged particles in each display cell may be of the same color or of different colors. Particles of mixed colors, when substantially evenly distributed, may be seen as one color, i.e., a composite color of different colors.
[0032] The particles may be positively or negatively charged.
[0033] Alternatively, the display fluid could also have a transparent or lightly colored solvent or solvent mixture and charged particles of two different colors carrying opposite charges, and/or having differing electro-kinetic properties. For example, there may be white pigment particles which are positively charged and black pigment particles which are negatively charged and the two types of pigment particles are dispersed in a clear solvent or solvent mixture.
[0034] The display cells are separated by slanted partition walls ( 102 ).
[0035] For the purpose of illustration, it is assumed that the particles in FIG. 2 and other figures are positively charged, throughout this application.
[0036] As shown in FIG. 2 , the positively charged pigment particles are allowed to move in either the vertical (up/down) direction or the planar (left/right) direction. For example, for display cell 101 a , when the voltage of the common electrode ( 108 ) is set low, and the voltages of the center electrode ( 109 ) and the side electrodes ( 110 a and 110 b ) are set high, the white particles would migrate to be near or at the common electrode ( 108 ). As a result, the white color (i.e., the color of the particles) is seen at the viewing side.
[0037] In display cell 101 b , when the voltage of the common electrode ( 108 ) is set high and the voltages of the center electrode ( 109 ) and side electrodes ( 110 a and 110 b ) are set low, the white particles would migrate to be near or at the bottom of the display cell. As a result, the color of the fluid (e.g., red, green or blue) would be seen at the viewing side.
[0038] In display cell 101 c , when the voltages of the side electrodes ( 110 a and 110 b ) are set low and the voltages of the common ( 108 ) and center ( 109 ) electrodes are set high, the white particles would migrate to be near or at the sides of the display cell. As a result, the color seen at the viewing side would be the color of the background layer ( 111 ) (i.e., black). In this current structure, the white charged pigment particles are hidden under the slanted partition walls ( 102 ), and therefore are not visible from the viewing side.
[0039] The full color displays of the present invention may be driven by an active matrix system or a passive matrix system as described in U.S. Pat. No. 7,046,228, the content of which is incorporated herein by reference in its entirety.
[0040] FIG. 3 illustrates the dimensions of the electrophoretic display structure of FIG. 1 . In a full color display, the total active area (mark A in the figure) is preferably at least about 50% of the total area of the viewing surface. The term “active area” refers to the area which is not part of the partition walls.
[0041] The angle α of the slanted partition walls is preferably in the range of about 25° to about 80°, more preferably in the range of about 50° to about 80°.
[0042] The second aspect of the invention is directed to an electrophoretic display structure in which the partition walls are indented as shown in FIGS. 4 and 8 .
[0043] FIG. 4 a is a three-dimensional view of a display cell having two indented partition walls on the opposite sides of the display cell. FIG. 4 b is a three-dimensional view of an electrophoretic display structure having display cells with indented partition walls. The display cells of FIG. 4 a have been turned 180° in the structure of FIG. 4 b.
[0044] The partition walls in FIGS. 4 a and 4 b are indented but the indented areas still separate the neighboring display cells. En other words, the indented partition walls do not have open passageways.
[0045] While two indented partition walls are shown in FIG. 4 a , a square-shaped display cell may have only one indented partition wall or may have two, three or four indented partition walls. In another embodiment, for a hexagon-shaped display cell, the display cell may have one, two, three, four, five or six indented partition walls.
[0046] FIG. 5 illustrates how a display structure of FIG. 4 b operates. In this example, it is shown that each display cell has two indented partition walls ( 515 ) on the two opposite sides of a square-shaped display cell. The side electrodes ( 510 a and 510 b ) are placed underneath the indented areas of the partition walls.
[0047] As shown in FIG. 5 , the charged pigment particles are allowed to move in either the vertical (up/down) direction or the planar (left/right) direction. For example, for display cell ( 501 a ), when the voltage of the common electrode ( 508 ) is set low, and the voltages of the center electrode ( 509 ) and the side electrodes ( 510 a and 510 b ) are set high, the white particles would migrate to be near or at the common electrode ( 508 ). As a result, the white color (i.e., the color of the particles) is seen at the viewing side.
[0048] In display cell 501 b , when the voltage of the common electrode ( 508 ) is set high and the voltages of the center electrode ( 509 ) and side electrodes ( 510 a and 510 b ) are set low, the white particles would migrate to be near or at the bottom of the display cell. As a result, the color of the fluid (e.g., red, green or blue) would be seen at the viewing side.
[0049] In display cell 501 c , when the voltages of the side electrodes ( 510 a and 510 b ) are set low and the voltages of the common ( 508 ) and center ( 509 ) electrodes are set high, the white particles would migrate into the indented areas. As a result, the white charged pigment particles are hidden in the indented areas, and therefore are not visible from the viewing side. The color seen at the viewing side would be the color of the background layer ( 511 ) (i.e., black).
[0050] FIGS. 6 a - 6 c are the top view of display cells and the electrode configuration on the second layer associated with the display cell.
[0051] FIG. 6 a shows the configuration of the side electrode ( 510 ) and the center electrode ( 509 ) for a display cell having only one indented partition wall. FIG. 6 b shows the configuration of the side electrodes ( 510 a and 510 b ) and the center electrode ( 509 ) of a display cell having two indented partition walls. FIG. 6 c shows the configuration of the side electrode ( 510 ) and the center electrode ( 509 ) of a display cell having four indented partition walls.
[0052] In one embodiment as shown in FIG. 7 , the thickness (t) of one indented area is about 5% to about 80%, of the total thickness (T) of a partition wall and the height (h) of the indented area is about 5% to about 80%, of the height (H) of a partition wall.
[0053] In FIGS. 4 and 5 , the indented areas are shown in a rectangular shape. The shape of the indented area is not limited to the rectangular shape and it may vary (such as a rectangular with an arched top), as long as it serves the same function and purpose of the indented area of a rectangular shape as shown.
[0054] FIG. 8 a is a three-dimensional view of a display cell having two open partition walls on the opposite sides of the display cell. FIG. 8 b is a three-dimensional view of an electrophoretic display structure having display cells with open partition walls. The display cells of FIG. 8 a have been turned 180° in the structure of FIG. 8 b.
[0055] In the structure of FIG. 8 b , the open partition wall area becomes an open passage area. In other words, the display fluid in one display cell may interchange with the display fluid in a neighboring display cell when the two display cells are separated by the open partition walls. Because the display fluid can move freely underneath the open areas in the partition walls, in this structure, the partition wall areas essentially have become “active”.
[0056] The opaque wall will create a hiding place for the particles. Alternatively, the ceiling of the open areas in the partition walls may be painted a color (e.g., black). The colored ceiling may be achieved by a process described below.
[0057] In one embodiment, the open partition walls are only on two opposite sides of a square-shaped display cell. The shape of the open areas is not limited to a rectangular shape as shown; it may vary as long as it serves the intended purpose and function.
[0058] FIG. 9 illustrates how a display structure of FIG. 8 b operates. In this example, it is shown that each display cell has two open partition walls ( 915 ) on the two opposite sides of a square-shaped display cell. The side electrodes ( 910 a and 910 b ) are placed underneath the open areas of the partition walls.
[0059] The height of the open areas is preferably about 5% to about 80%, of the height of the partition wall.
[0060] As shown in FIG. 9 , the charged pigment particles are allowed to move in either the vertical (up/down) direction or the planar (left/right) direction. For example, for display cell ( 901 a ), when the voltage of the common electrode ( 908 ) is set low, and the voltages of the center electrode ( 909 ) and the side electrodes ( 910 a and 910 b ) are set high, the white particles would migrate to be near or at the common electrode ( 908 ). As a result, the white color (i.e., the color of the particles) is seen at the viewing side.
[0061] In display cell 901 b , when the voltage of the common electrode ( 908 ) is set high and the voltages of the center electrode ( 909 ) and side electrodes ( 910 a and 910 b ) are set low, the white particles would migrate to be near or at the bottom of the display cell. As a result, the color of the fluid (e.g., red, green or blue) would be seen at the viewing side.
[0062] In display cell 901 c , when the voltages of the side electrodes ( 910 a and 910 b ) are set low and the voltages of the common ( 908 ) and center ( 909 ) electrodes are set high, the white particles would migrate into the open areas. As a result, the white charged pigment particles are hidden in the open areas, and therefore are not visible from the viewing side especially if the open partition walls have a colored or black ceiling. The color seen at the viewing side would be the color of the background layer ( 911 ) (i.e., black).
[0063] This type of display structure is particularly suitable for a striped color display device as shown in FIG. 10 . In the display device as shown, all display cells of the first row are filled with a display fluid of the red color; all display cells of the second row are filled with a display fluid of the green color; and all display cells of the third row are filled with a display fluid of the blue color.
[0064] Each display cell in this case represents one color sub-pixel. There are no open areas in the partition walls in the horizontal direction. The partition walls in the vertical direction have open areas which allow the display fluid of the same color to move through, in each row.
[0065] The display cells with red, green and blue display fluids respectively aligned to the sub-pixels on a backplane to form one pixel unit of an electrophoretic display device.
[0066] The display structure of FIG. 8 b is also suitable for a binary color system. As shown in FIGS. 11 and 12 , the open partition walls ( 1117 ) randomly appear in the structure. The non-open partition walls are marked 1118 . For illustration purpose, it is assumed that the display device shown in the figure is a black/white binary color display. In other words, the display fluid in this example comprises white particles dispersed in a black color solvent. To ensure high contrast ratio, an auxiliary layer ( 1107 ) is placed underneath the display cells. The auxiliary layer, for example, is of the black color and it may be an adhesive layer.
[0067] FIG. 12 illustrates how the display structure of FIG. 11 operates.
[0068] When the white particles move to be at or near the common electrode ( 1108 ), the white color is seen in the display cells from the viewing side. In the non-open partition wall area ( 1118 ), the black color from the auxiliary layer ( 1107 ) is seen from the viewing side. In the open partition wall area ( 1117 ), the white color of the particles is seen, as the display cell structure is transparent.
[0069] When the white particles move to be at or near the center electrode ( 1109 ), the black color is seen in the display cells from the viewing side. In the non-open partition wall area ( 1118 ), the black color from the auxiliary layer is seen from the viewing side. In the open partition wall area ( 1117 ), the black color of the solvent is seen, although the black color is not as intense as that of the display cell area because in the open partition wall area the fluid level is not as deep as that in the display cell area.
[0070] The increase of the overall black color intensity results in an overall higher contrast ratio of the binary color display device.
[0071] All of the display structures described in the present application can be prepared by techniques such as microembossing. An embossing composition is usually first coated on an ITO layer. A male mold is then pressed onto the embossing composition from the top to form display cells of a desired configuration (e.g., slanted, indented or open partition walls). After the display cells are formed, the display fluid may be filled into the display cells and the filled display cells are optionally sealed. In order for the partition walls to achieve the function of hiding the particles, the structure formed after the embossing process is turned 180° in forming a display device.
[0072] The embossing male mold can be made using a diamond turn method. A photolithography method may also be used; but two masking steps are needed to create the open partition walls. All of the display structures of the present invention may be manufactured by a continuous or semi-continuous process in a roll to roll manner as described in U.S. Pat. No. 6,930,818, the content of which is incorporated herein by reference in its entirety.
[0073] In order to color the top surface of the partition walls without contaminating the display cells, a masking layer may be applied before spraying the black ink. An aqueous masking solution can be used in combination with a liquid black ink and the masking layer may be stripped with water to remove any black paint in the masking area. Details of the processes for coloring the top surface of the partition walls black may be found in U.S. Pat. No. 6,829,078, the content of which is incorporated herein by reference in its entirety.
[0074] While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation, materials, compositions, processes, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. | This invention relates to a display device comprising a plurality of display cells, wherein said display cells are separated by slanted partition walls. This invention also relates to a display device comprising a plurality of display cells, wherein said display cells are separated by indented partition walls having indented areas. The electrophoretic structures of the present invention may be manufactured by a continuous or semi-continuous roll-to-roll manufacturing process. The structures in which display cells are separated by slanted partition walls or partition walls having indented areas are capable of providing enhanced color states. | 6 |
The present invention relates to a gas turbine power plant with a pressurized fluidized bed for the burning of particulate coal, and more particularly a protective control system for such power plant.
BACKGROUND OF THIS INVENTION
The gas turbine power plant, as exemplified in the U.S. Pats. to Jubb et al No. 3,791,137, dated Feb. 12, 1974, and Moskowitz et al, No. 4,164,846 dated Aug. 21, 1979, and the article by V. de Biasi entitled "AEP designing a 60-Mw `PFB` gas turbine plant" which appeared in the March 1977 issue of Gas Turbine World magazine, comprise a fluidized bed reactor or combustor in which compressed air from a gas turbine driven compressor is utilized to suspend particles of coal and sulphur dioxide sorbent and to provide the oxygen for support of the burning of the coal. The gaseous products of combustion are conducted from the combustor, through separators for removal of entrained solids (gas clean-up system), to a gas turbine for driving a load, such as an electrical generator.
In the operation of such gas turbine power plants, a problem encountered is compressor surging and damage resulting therefrom upon load loss when the gas turbine is intentionally or accidentally shutdown. Since the fluidized bed combustor and the separator or combustion product clean-up system provides an extremely large volume of pressurized, high temperature gaseous fluid (as for example, a gas volume of about 55,000 cubic feet at a temperature between 371° C. and about 1051° C.) which cannot be dissipated quickly, there occurs flow of gaseous fluid from the fluidized bed combustor in a direction toward the compressor when the plant is shutdown and the compressor output is diminished or dumped. This backflow of hot gaseous fluid causes a back pressure at the compressor discharge port which surges into the compressor and may cause damage to the compressor. Also, further damage to the compressor and other components may occur because of the hot gases, and particulate solids, such as unburned coal, dolomite and ash, entrained in the gaseous fluid.
It is, therefore, an object of this invention to provide a protective control system for a gas turbine power plant having a pressurized, fluidized bed combustor, which system obviates surging of the compressor and entrained solids carryover into the compressor upon loss of turbine loading.
Another object of the present invention is to provide a protection control system for a gas turbine power plant having a pressurized fluidized bed combustor, which system permits shutdown of the plant, including the fluidized bed combustor, without backflow of gaseous fluid from the fluidized bed combustor to the compressor and the resulting surging and damage to the compressor.
SUMMARY
It is, therefore, contemplated by the present invention that a protective control system be provided in a gas turbine power plant of the type having a pressurized fluidized bed combustor in which particulate solid fuel is burned to produce pressurized combustion gases. An air compressing means having air inlet and air discharge ports is connected by a first conduit means to conduct compressed air from the compressor air discharge port of the pressurized fluidized bed combustor for suspending the particulate solid fuel and inert materials (fluidization) and support combustion of the fuel. The plant also has an expander, as for example a gas turbine, connected by a second conduit means to receive combustion gases from the fluidized bed combustor to thereby be driven.
The protective control system comprises a valve means in the second conduit means for controlling flow of combustion gases therethrough and in one operative position functions to stop flow of combustion gases to the expander. An automatic means, as for example check valve means, is located in the first conduit means to present flow of gaseous fluids in the first conduit means, from the fluidized bed combustor, in a direction toward the air compressing means. A vent means is provided for blowdown of the fluidized bed combustor upon shutdown of the plant.
The protective control system in a narrower scope of the invention comprises the first conduit means, including three branch conduits, for conducting one portion of the compressed air from the compressing means to the fluidized bed combustor for suspending particulate fuel solids and sulphur dioxide sorbent and supporting the particulate solid fuel for combustion, for conducting a second portion of the compressed air to a heat exchanger in the fluidized bed combustor for controlling the temperature of the latter, and for conducting a third portion of the compressed air to separating means for assisting in the removal of entrained solids in the combustion gases and wherein the automatic means includes at least two check valves, one being located between two of the branches of the conduit means while the other check valve is disposed between the discharge port of the compressing means and the other of the three branches.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more fully understood from the following description, when considered in connection with the accompanying drawing, in which a gas turbine plant having a pressurized fluidized bed combustor is shown with the protective control system according to this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to the drawing, the reference number 10 generally refers to the gas turbine power plant having a protective control system according to this invention.
The power plant 10 comprises a pressurized fluidized bed combustor 12 which is provided with three transversely extending partitions 14, 15 and 16 which divide the interior of the fluidized bed combustor into a reaction or combustion zone 18, two inlet plenums 20 and 22 and an outlet plenum 24. The fluidized bed combustor 12 is connected, via a conduit 26, to a particulate solid fuel supply means 28 to receive particulate solid fuel in the combustion zone 18. The particulate solid fuel for burning in fluidized bed combustor 12 may be coal. Also, the fluidized bed combustor 12 is connected to a supply means 30, via a conduit 32, to receive in combustion zone 18 a sulphur dioxide absorbing material, as for example crushed dolomite. The partition 14 may be perforated or be provided with tuyeres to distribute air from plenum 20 into combustion zone 18. To control the reaction temperature in combustion zone 18, a heat exchanger 34 is disposed in combustion zone 18 and is connected to receive air from inlet plenum 22 and to discharge heated air into outlet plenum 24. Ash produced in combustion zone 18 is removed from combustion zone 18 through a discharge conduit 21, an ash cooler 23 and an ash hopper 25.
Compressed air is supplied to inlet plenum 20 from a compressor 38 by way of a main pipe 36 and branch pipe 40, while cooling air from air compressor 38 is delivered to inlet plenum 22 by way of main pipe 36 and another branch pipe 41. Flows of compressed air through branch pipes 40 and 41 are regulated by valves 42 and 44 in the respective pipes. The valves 42 and 44 are adjusted to provide a distribution of the compressed air discharged by compressor 38 so that about one third (1/3) is conducted to plenum 20 for suspension of the fuel particles and for support of combustion of the fuel, while about two-thirds (2/3) of the air is delivered to plenum 22 for flow through heat exchanger 34 and cooling of the combustion zone 18.
A bypass pipe 46 is connected at one end to main pipe 36 to receive, from the latter, compressed air and to pass the compressed air to an auxiliary combustor 48. Fuel, such as oil or gas, is selectively injected into auxiliary combustor 48 to provide hot gases to pipe 40 and thence to plenum 20 when it is necessary to heat the compressed air, as in the start-up mode of operation. A valve 50 is provided in bypass pipe 46 to control flow of compressed air to auxiliary combustor 48.
A start-up combustor 52 is connected by a pipe 54 to main pipe 36 to receive compressed air from the latter for the combustion of oil or gas fuel therein and the generation of combustion gases. A valve 55 is provided in pipe 54 for controlling flow through the pipe. The combustion gases are carried from the start-up combustor to a turbine 56 by way of pipe 58 and a clean combustion gas pipe 60. The clean combustion gas pipe 60 has a valve 61. The turbine 56 is connected to drive compressor 38.
A clean-up system is provided in plant 10, which system comprises a plurality of separators 62, 64, 66 and 68 which are serially connected together by conduits 70, 72, and 74 to sequentially receive combustion gases discharged from fluidized bed combustor 12 through an outlet conduit 76. Separator 62 is connected through a conduit 71 to fluidized bed combustor 12 so that unburned particles of fuel entrained in the combustion gases and separated therefrom in separator 62 are returned to the combustion zone 18 for burning. The clean combustion gases are discharged from separator 68 by outlet conduit 78 and thence flowed into clean combustion gas pipe 60 for passage to turbine 56. The outlet conduit 78 is also connected to a vent means comprising a pipe 80 which has a valve 82 and is connected to a pressurized water scrubber 84, the water scrubber 84 being vented through a pipe 85 through which flow of fluid is controlled by a valve 86. Separator 68 is of a type which requires air and, therefore, is connected to fluidized bed combustor 12 by a pipe 88 which communicates, at one end, with outlet plenum 24 of fluidized bed combustor 12 and, at the other end, communicates with separator 68. Some compressed air can be delivered directly to separator 68, through a bypass pipe 90 which is connected to main pipe 36 and pipe 88. A valve 92 is disposed in pipe 90 to control flow therethrough. Compressed air can be made to bypass separator 68 and flow into clean combustion gas pipe 60, via bypass pipe 94 which has a valve 96.
The gas turbine 56 is connected to exhaust combustion gases to a free power turbine 100 by conduits 102 and 103. An isolation valve 104 is disposed in conduit 103 to control flow of exhaust gases from turbine 56 into power turbine 100. Also a valve controlled bypass conduit 106 is provided to pass exhaust gas from turbine 56 to the discharge conduit 108 of power turbine 100. A conduit 110 is provided to conduct exhaust gas from exhaust conduit 108 of free turbine 100 to a waste heat boiler (not shown) or from exhaust conduit 102 of turbine 56. A valve 112 is provided in conduit 110 to permit exhaust gas from turbine 56 to bypass free power turbine 100 and to be conducted to the waste heat boiler. The free power turbine 100 is connected to drive a load such as an alternator 114.
The protective control system according to this invention comprises a bypass pipe 116 which is connected to main pipe 36 and at the other end to atmosphere, via a silencer (not shown). The bypass pipe 116 has an anti-surge valve 118 which can be opened to dump compressed-air-discharge to atmosphere upon emergency shutdown of the plant on sudden load loss. An automatic means for preventing flow of gaseous fluid in main pipe 36 in a direction from fluidized bed combustor 12 to compressor 38 is provided. This automatic means comprises at least one check valve 120 disposed in main pipe 36 downstream from the junction of pipe 116 and main pipe 36 and, may include, a second check valve 122 disposed in main pipe 36 between the junctures of pipes 38 and 40 with main pipe 36. The check valve 122 functions to prevent flow of gases from fluidized bed combustor 12 into turbine 56 via pipes 38, 36, 54, 58 and 60 or pipes 38, 36, 90, 94 and 60 in situations where valves 42, 50 and 55 or valves 42, 50, 92, 96 and 61 remain open upon sudden loss of load or shutdown of the plant. To effect shutdown of plant 10 and the blowdown or depressurization of fluidized bed combustor 12 and the clean-up system comprising separators 64, 66 and 68, valves 82 and 86 are opened and valve 61 is closed to thereby vent the fluidized bed combustor and clean-up system through pipes 80 and 85. The vented gases are scrubbed in scrubber 84 before being discharged into the atmosphere to avoid any possibility of pollution.
It is believed that it is now readily apparent that a protective control system for a gas turbine plant, having a pressurized fluidized bed combustor, has been disclosed which permits an air compressor to be vented during load losses and the pressurized fluidized bed combustor to be blowndown without causing the air compressor to surge or to be damaged by particulate solids entering the compressor through its discharge port.
Although but one embodiment has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes can be made in the arrangement of parts without departing from the spirit and scope of the invention as the same will be now understood by those skilled in the art. | The protective control system for a gas turbine power plant having a pressurized fluidized bed combustor provides check valve means located in the passage supplying compressed air from a compressor to the combustor so as to prevent, upon loss of load or shutdown of the plant, reverse flow of high pressure, high temperature, dirty gaseous fluid from the combustor to the compressor and thereby prevent contamination, surging and damage to the compressor. Also a vent means is provided downstream of the combustion gas clean-up system to effect blowdown or depressurization of the combustor. | 5 |
CROSS REFERENCE
[0001] This application claims the benefit of the filing date of U.S. Provisional Application No. 61/892,166 having a filing date of Oct. 17, 2013, the entire contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a system including a set of sensors capable of collecting information on the environment of a vehicle-ground interface, and methods for the use of this information to improve vehicle safety.
BACKGROUND OF THE INVENTION
[0003] Environmental conditions significantly impact vehicle behavior. This is most commonly noted as degradation of vehicle stopping capabilities in inclement weather such as snow or ice. Such degradations mean that driver behavior should ideally adapt to match immediate road conditions, and that in some cases drivers should entirely avoid areas deemed to be too dangerous, for example those with “black ice”.
[0004] Road conditions can be generally estimated based on known weather conditions. However, both weather conditions and road temperatures can vary dramatically over short distances, so that general area weather forecasts are insufficient to provide specific driving advice to a vehicle in a particular area. Thus, more granular data on weather, and specifically on road conditions, would be of value to improve the safety of drivers.
[0005] Stopping distance and general vehicle safety also depends dramatically on the specific vehicle being driven. Vehicle stopping distances may vary based on vehicle model, vehicle weight, brake quality, and tire tread conditions. Thus, in a defined road location two vehicles with different characteristics may experience dramatically different stopping distances. As a result, knowledge of the weather or road conditions themselves are not sufficient to ensure driver safety.
[0006] The interplay between vehicle and road at a given instant is considered as an input in existing anti-lock braking systems (ABS). In such systems, the tangential acceleration of one or more wheels is measured and compared with the acceleration rate of the vehicle. Because the tire has lower mass than the vehicle it can decelerate much more quickly than the vehicle, and as a result the tire can “lock” in a state where it does not rotate. This locking is undesirable, because the co-efficient of friction of a tire in its locked state is substantially lower than the optimal coefficient of friction for that tire.
[0007] ABS uses a closed-loop control process to optimize the amount of rotation in the tire, and thus optimize coefficient of friction. In ABS, the amount of force applied to the brakes is automatically relaxed if lock (or, more generally, slip) is detected in order to allow the tire to rotate again. The braking is re-established once rotation is sensed. Ideally, this system functions so that the optimum coefficient of friction (corresponding to an optimum amount of tire slip) is maintained during braking.
[0008] While the above closed-loop system can provide excellent control over vehicle braking in an emergency situation, it is not capable of making predictions of future vehicle safety performance, or of assessing its performance versus a baseline. While ABS assures “optimum” braking for the particular emergency case, there is no ability to analyze whether this “optimum” is good enough—whether it represents a safety performance level that will be satisfactory in other situations.
[0009] Thus, while it is possible to provide general advice for a generic vehicle during inclement weather, and it is possible to optimize the safety of a specific vehicle after a loss of control has occurred, it is not currently possible to provide targeted advice to a vehicle about how well it can perform in specific weather conditions and/or upcoming road conditions.
SUMMARY OF THE INVENTION
[0010] The presented inventions are directed to a system that includes sensors and sensor systems, and methods for analyzing data from these sensors, in order to measure characteristics of the tire/road interface in varying environmental conditions, as well as to provide information, guidance, and predictions to drivers, fleet managers, traffic managers, safety services, navigation and/or self-driving vehicle systems, models, services and other interested parties that use weather information and predictions.
[0011] One aspect of the invention is the fusion of multiple sensors, sources of information (including databases) along with models to create or provide information that is not available through the individual sensors alone. In effect, many sensors are actually effected through sensor fusion—for example, differential GPS is effected using the outputs of more than one GPS sensor. If the sensors are not conveniently co-located, the communication system(s) become an integral part of the sensor fusion. In many sensor fusion applications, processing power and modelling are also an integral part of the sensor fusion. Data used in the model(s)—say data from a database—may become, in essence, another sensor that is fused. An example here would be the street map database for a Geographic information system (GIS) being fused with GPS information to display a real time position map on a smartphone of a moving cars position.
[0012] In one embodiment, sensor fusion is done before transmission to reduce the use of limited bandwidth, and to reduce the costs associated with using costly bandwidth (e.g. cell connections). In another embodiment, models reside on the sensor or hubs processor to reduce the costs or bandwidth of transmission, and these models may be updated using OTA.
[0013] In some embodiments, the presented inventions includes inertial measurement sensors comprising accelerometer(s), gyroscope(s), and/or magnetometer(s) that are added to a vehicle to measure its motion. In some embodiments, these inertial measurement sensors are added directly to one or more wheels of the vehicle to measure its tangential motion, velocity, and/or acceleration. One or more such sensors may be added to a non-rotating member of the vehicle such as the bumper to measure its linear and angular motion and or position. In some embodiments, the sensors are added at the lug nut of the wheel to capture tangential acceleration at this position. In other embodiments, one or more sensors are added to a tire pressure monitoring system (TPMS), or affixed inside or outside of the tire or axel.
[0014] In one aspect of the presented inventions, sensor data is used to compute coefficients of friction and slip ratios for the vehicle in certain situations. For example, the wheel rotational acceleration and/or velocity are compared with the linear vehicle acceleration and/or velocity and the difference between the two are computed in order to provide an estimate of coefficient of friction and/or slip ratio. Multiple such measurements may be utilized to generate curves, equations and/or tables of coefficient of friction vs. slip ratios. Likewise, such curves, equations and/or tables may be generated for differing environmental and/or road conditions. In another example, the change in velocity and/or acceleration of a vehicle is calculated during a braking situation in order to provide an estimate of coefficient of friction. In some embodiments, this rate of change is measured by using GPS to identify the known distance over which braking has occurred, and measurement of the total time of braking in order to establish the time over which braking has occurred. In some embodiments, the wheel rotational orientation and vehicle speed along a road with a known geometry is measured in order to estimate the weight of the vehicle. In some embodiments, sensors such as radar, lidar, sonar, or (e.g. 3D) computer vision are used to measure/estimate the distance to other objects, which can be combined with stopping distance information to provide safety information. In some embodiment, computer vision is used to determine visibility, weather conditions (e.g. sleet hail, or black ice), road conditions (e.g. potholes and buckling) and roadside hazards and issues (e.g. semi-tractor trailer tires that have been shed, dead animal etc.). In other embodiments, the tire pressure is measured in order to estimate the vehicle's tire radius and/or contact surface with the ground.
[0015] In another aspect of the presented inventions, profiles of coefficients of frictions and slip ratio and plots of coefficient of friction (COF) versus slip ratio for a vehicle are compiled over time, across a variety of road environments. In one embodiment, these profiles are tagged with information about geographic position and/or are tagged with information about time. In one embodiment, these profiles are tagged with information about environmental conditions. Such environmental conditions may be identified from information provided from the National Weather Service or National Center for Atmospheric Research's (NCAR's) Pikalert system, Road Weather Information System (RWIS), Meteorological Terminal Aviation Routine Weather Report (METAR) or Terminal Aerodrome Forecast (TAF), UCAR's Location Data Manager (LDM) Etc. In another embodiment, the environment conditions are derived, at least in part, by sensor(s) on or near a vehicle at the time the measurements relating to coefficient of friction and slip ratio are taken. In one embodiment, local precipitation is measured using a precipitation gauge mounted on the vehicle, for example on the front windshield. In such an embodiment, the type of precipitation (e.g., rain, snow) is measured directly by the precipitation sensor or inferred from a combination of sensor measurements. In one embodiment, local road temperature and conditions are monitored by an infrared camera mounted to the vehicle, for example on the vehicle bumper. Likewise, light or camera sensors may be used to detect/measure cloud cover. Further, motion sensors may be used to detect/measure wind velocity and gusts.
[0016] In one embodiment, at least one of these sensors communicates to a hub device using a wireless communications protocol. In one embodiment, this wireless communications protocol is Bluetooth or Bluetooth Low Energy. In one embodiment, this wireless communication uses a technique other than conventional electromagnetic radiation, such as magnetic or acoustic communication. In one embodiment, the hub device is a cellular phone. In one embodiment, this cellular phone has one or more applicable sensors, such as an Inertial Measurement Unit. In one embodiment, the hub is connected to the On Board Diagnostics (OBD) system of the car, drawing power and/or measurements from the OBD. In one embodiment, the hub is a device capable of running many applications that make use of the systems capabilities (e.g., an Android device).
[0017] In still another aspect of the presented inventions, the COF or COF vs slip ratio curve for a vehicle are predicted for future environmental conditions and/or future road conditions based on the past COF performance of the vehicle. In one embodiment, the future environmental condition is chosen based on a vehicle's expected travel path. In one embodiment, the future environmental condition represents the present environmental condition at a location that the vehicle will soon be in. In one embodiment, the future environmental condition includes a prediction of the environmental state of that location based on a combination of the present environmental condition and a model that predicts environmental changes. In one embodiment, the future environmental condition is derived at least in part from a report from the National Weather Service. In one embodiment, the future environmental condition is derived at least in part from environmental data taken at that location by fixed sensors. In one embodiment, the future environmental condition is derived at least in part from environmental data taken at that location by mobile sensors. In one embodiment the mobile sensors are affixed to other vehicles. In another embodiment, future road conditions are derived at least in part from road condition information taken by mobile sensors. In one particular embodiment, future or upcoming coefficient of friction information and/or environmental information for a travel path of a vehicle are provided to the vehicle. This upcoming road surface information may be utilized with stored profile information of the vehicle to determine vehicle specific safety information and/or to generate warning outputs.
[0018] In yet another aspect of the invention, the future COF is obtained by matching the previously measured COF values and/or curves with environments that resemble the future environment, and selecting COF values that most closely match that environment. In one embodiment, the future COF is obtained by first building a model for COF as a function of environmental conditions for a particular vehicle, and then extrapolating from this model to predict the COF for these future environmental conditions. In one embodiment of the invention, data from one or more sensors, vehicles, etc., is stored in a computer database. In another embodiment, models are constructed using Big Data (data analytics/predictive analytics) methods and/or control theory methods such as system identification.
[0019] In further aspects of the invention, COF and COF versus slip ratio data for a plurality of vehicles are compiled to form a library of COF data. In one embodiment, data from more than one vehicle in this library is combined to form at least one element of an assessment of road conditions in a specific location common to these vehicles. In one embodiment, the future COF of a first vehicle is predicted based on a mathematical model which comprises data from vehicles other than this first vehicle.
[0020] In still yet another aspect of the invention, the driver, owner, insurer, or other interested party of a vehicle are alerted to the potential for poor safety performance at a future time. In one embodiment, the interested party is notified if the vehicle's future path is anticipated to take the vehicle to a location where its predicted COF will be below a threshold level. In another embodiment, the interested party is notified if the COF is predicted to fall below a threshold value in weather conditions that are common to the vehicle location. These alerts may be output in any appropriate manner to a driver of the vehicle and/or to vehicle systems (e.g., traction control).
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a relationship between COF and slip ratio.
[0022] FIG. 2 shows an illustration of the forces impinging on a block sliding on an inclined plane.
[0023] FIG. 3 shows a perspective view of a vehicle with sensors formed in accordance with embodiments of the invention.
[0024] FIG. 4 shows a block diagram of communication and processing systems formed in accordance with various embodiments of the invention.
[0025] FIG. 5 shows an exploded view of a lug nut sensor formed in accordance with one embodiment of the invention.
[0026] FIG. 6 shows an exploded view of a wheel-mounted sensor at or near the tire pressure measurement system formed in accordance with one embodiment of the invention.
[0027] FIG. 7 shows an exploded view of a bumper sensor suite formed in accordance with one embodiment of the invention.
[0028] FIG. 8 shows an exploded view of a windshield sensor formed in accordance with one embodiment of the invention.
[0029] FIG. 9 shows an exemplary system that forms a COF/slip profile from sensor data.
[0030] FIG. 10 shows an exemplary system that estimates current environmental conditions from sensor data.
[0031] FIG. 11 shows an exemplary system that notifies an interested party in the vehicle if the vehicle is anticipated to encounter a potentially hazardous environment.
[0032] FIG. 12 shows an exemplary system that combines multiple vehicle outputs and/or profiles into a library which can be used to predict vehicle performance in future environments.
[0033] FIG. 13 shows exemplary COF/slip profiles for a vehicle for different environmental/road conditions.
[0034] FIG. 14 shows a travel path of a vehicle with road surface information for different road segments of the travel path.
[0035] FIG. 15 shows an alternate suggested route for the travel path of FIG. 14 .
[0036] FIG. 16 shows a process for generating safety outputs at a vehicle.
[0037] FIG. 17 shows a process for gathering and distributing road surface information.
DESCRIPTION OF THE INVENTION
[0038] The present invention identifies new and surprising methods for improving vehicle safety by enabling prediction of coefficient of friction, slip ratio, and/or stopping distance for a specific vehicle at a time in the future. The present invention includes sensor(s) and components that perform analysis techniques to customize a prediction to a particular vehicle in order to optimize the utility of the information.
[0039] Generally, aspects of the presented inventions use techniques of “information fusion” to create new information. A definition of information fusion is provided by the International Society of Information Fusion: “Information fusion is the study of efficient methods for automatically or semi-automatically transforming information from different sources and different points in time into a representation that provides effective support for human or automated decision making.” These different sources can include at least two elements from the classes comprising sensors, external data sources, mathematical models, algorithms, etc., as well as combinations of these elements that may be generically described as sensors in these descriptions
[0040] Information fusion can be used to combine measurements/data (and information) from more than one source—often in concert with models in ways that allow one to access information and make predictions about quantities and qualities using sensor fusion and/or information fusion that are not present in any raw measurements/data from one source. A model in this context represents a mathematical representation of a physical system, wherein, for example, the physics of one characteristic can be estimated or predicted based on input values from other characteristics, and includes a broad range of techniques such first principle dynamic models, statistical models, system identification, and neural network and deep learning systems. Data generated by such a process can be broadly called “fusion data”, and may be used directly or serve as an input to another model.
[0041] This analysis can result in an estimate of a characteristic of a system that is not directly measured by the sensors. Additionally, one can fuse two measurements of similar quantities into improved information, for example using two measurements—one accurate not precise, and one precise but not accurate—into an estimate of the quantity which is both more accurate and precise.
[0042] Sensors and information sources which have applications to vehicle sensor/information fusion and or safety include: vehicle sensors networked to the On Board Diagnostics (OBD, dashboard cameras (including dual, three-dimensional, and array cameras, and rearview/backup and/or 360 view cameras, as well as driver and passenger facing cameras), spectroscopic sensor systems, visibility sensors (e.g. extinction coefficient backscattering sensors or integrating nephelometer), sensors such as magnetic loops, micro radar, temperature, and magneto-restive wired and wireless sensors (which may or may not be embedded in the pavement), toll-taking sensors (including RFID, DSRC, and other technologies), distrometers, particulate counters, and ceilometers, lightning sensors, linear optical arrays, proximity detectors, magnetic position sensors, gas sensors, color sensors, infrared pyrometers (especially in linear arrays) and cameras (e.g. temperature sensors), RFID and other location tagging, blind spot sensors such as radar, car ahead-behind distance sensors, and pavement sensors optical and spectral analysis sensors, battery “fuel gauges”, infrared pyrometers, and location technologies such as GPS, Galileo, and Glonass, as well as integrated systems such as GNSS, sensors for precipitation type and amounts, wiper sensor, irradiance and UV/IR sensors (useful both for weather measurements and as instrumentation for estimating available Photovoltaic energy), cloud sensors, roadside snow sensors, computer vision (e.g. sensing lane markers, other vehicles, and roadside traffic markers), lightning sensors, barometric pressure, particulate count, and pollution and chemical sensors, sonic sensors and microphones (e.g. sensors for use in creating sonic profiles of road and tier noise and/or doing FFT analysis of sounds, for the purposes of sensing road surface type, road surface conditions, and precipitation-tire interaction), range finding sensors (e.g. distance to vehicle in front/back), mems sensors, etc. Sensors may also be in the form of information from vehicles and vehicle management systems, such as traffic jam auto drive, auto park, parking space management, and GIS systems with mutli-layer data sets about vehicles, conditions, weather, predictive analytics, etc. Sensors may be the outputs of smart phone and/or car sensor sets—connected to internet via cell, wifi, Bluetooth, etc. Smart phones themselves make excellent information fusion devices, containing a growing number of sensors and communications methods, as well as ever-increasing processing power and access to algorithms and databases via the internet.
[0043] These sensors can, as is appropriate, be connected sensors on vehicles, infrastructure, or persons, be part of connected technologies such as smart phones, smart watches, personal computers, vehicle instrumentation, be part of safety systems such as National Weather Service warning systems, police and fire response, traffic accident reports and lane closure warnings, General Motors OnStar system, etc. Sensors may also be in the form of crowd-sourced information, databases information, broadcasts, etc.
[0044] Sensors, information databases, models, processing power (including cloud technologies), and other elements of information fusion are now often distributed, and thus communications between these elements may be critical. Cell communications have become ubiquitous methods of communication, and have become well integrated in vehicle applications—standards include GSM (Global System for Mobile Communications, a de facto global standard for mobile communications that has expanded over time to include data communications. Other standards include third generation (3G) UMTS standards and fourth generation (4G) LTE Advanced standards. Additional communication methods applicable for the invention include: Satellite internet and telephony, Bluetooth and Bluetooth low energy, wifi, using regulated and unregulated frequency's (such as ISM), whitespace, DSRC (Dedicated Short Range Communications) including but not limited to vehicle to vehicle (including ad hoc networking for passing info such as braking, swerving, GPS position and velocities for avoidance, or in our case COF-Slip) and vehicle to infrastructure (such as traffic signals and signs), radio, repeaters, VHS (such as aircraft bands), infrared, spread spectrum, mobile ad hoc networks (MANETs) and mesh networks, public information systems such as the 5-1-1 telephone car information system (road weather information, ans transportation and traffic information telephone hotline) and National Weather Service Emergency Broadcast systems, and police, fire, ambulance, and rescue bands and systems. This list (and others in this specification) are to be considered illustrative and in no way limiting.
[0045] In one embodiment, input to a model takes the form of a specific measurement (e.g., a value). Input to a model can also take the form of a relationship between two variables, which together define a curve. An example value is the instantaneously measured wheel slip ratio of a vehicle. An example curve is a plot of a relationship between wheel slip ratio and COF for a specific environmental condition. A curve includes measured data and/or data extrapolated from models.
[0046] In one embodiment, input to a model takes the form a more complex “profile”, which includes an array of data associated with a given vehicle. An example profile in this invention is an array of COF versus slip ratio curves for a single vehicle in a number of different environmental conditions. In one embodiment, a profile includes measured data as well as data extrapolated from models. In one embodiment, this profile(s) is stored at the vehicle in a memory unit. In another embodiment, this profile(s) is stored remotely from the vehicle and is accessible by the vehicle and/or similar vehicles via a communications module. In the latter regard, vehicles that have not yet calculated a profile(s) or dot not have adequate sensors to calculate such a profile(s) can access pertinent profile information.
[0047] In one embodiment, input to a model takes the form of a “library”. A library includes a set of multiple profiles. For example, such a library may include COF data from all vehicles that have passed by a particular location and/or includes COF data from a set of similar vehicles, or vehicles with similar tires, or of similar ages, etc. A library is used for inferring the anticipated characteristics of a specific vehicle by comparison with other, similar vehicles. A library includes measured data as well as data extrapolated from models.
[0048] Output from the model is termed a “prediction”, and represents an estimate of the current or future state of a variable that is not directly measured by the sensors. An example prediction from a model is the maximum COF of a vehicle in environmental conditions in a region beyond the exact region of the vehicle at a particular moment. A “vehicle” in this invention can refer to one or more commonly used transportation systems, including a car, a self-driving car or drone, truck, etc.
[0049] One metric of the safety of a vehicle is the vehicle stopping distances. The stopping distance is determined by several factors, including the speed of the vehicle, the mass of the vehicle, and the coefficient of friction between the vehicle and the road. While the vehicle mass can be reasonably estimated by the driver, and its speed is constantly measured by the speedometer, the coefficient of friction is usually not known to the driver, as it is not measured or reported by vehicle systems. The coefficient of friction represents the most significant uncontrolled variable in vehicle safety. Worse, the coefficient of friction can change suddenly on a road, for example as a vehicle moves from dry road to a puddle, or from snowpack to black ice. As a result, road safety is best quantified through coefficient of friction, and means to both measure and predict coefficient of friction produce valuable safety improvements.
[0050] The coefficient of friction at the tire/road interface varies as a function of the “slip ratio” of the wheel, where a slip ratio of zero indicates a freely rolling tire, and a slip ratio of one indicates a completely locked tire. Without being bound by theory, it is believed that the coefficient of friction between tire and road has a maximum at a specific slip ratio. FIG. 1 shows a typical relationship between coefficient of friction and slip ratio. A relationship such as this is referred to as a “COF curve” for a specific road condition. Anti-lock brakes attempt to maintain the COF as close as possible to the maximum value of this curve during aggressive braking. A locked wheel has significantly lower COF than the maximum achievable COF, and is therefore to be avoided if possible. The exact details of this curve, including the COF maximum value, depend on the specifics of the tire, vehicle velocity, and the environmental conditions of the road (e.g., clean dry asphalt, dirt road, packed snow on concrete, etc.).
[0051] In one embodiment, the present invention produces one or more profiles of COF values and COF curves associated with a particular vehicle. See, for example, FIG. 13 . The profiles are created by measuring COF and/or slip ratio using at least one sensor under at least two environmental conditions, and storing the values of COF and/or slip ratio in a database. Such profiles may be stored alongside descriptive information about the environment. The descriptive information may include time, location (e.g., as determined by GPS), other sensor information, local weather conditions, etc. The descriptive information may also include pointers to other information sets, such as weather databases, which are not locally included in the database. Further, such profiles may be periodically updated. This allows changing of a vehicle specific profile as conditions of the vehicle change. This may allow, for example, altering profiles as the tires of the vehicle wear.
[0052] The instantaneous ratio of the tangential velocity of the tire where it meets the road and the velocity of the vehicle to which it is attached is defined as the “Slip ratio”. When braking (or accelerating) in a moderate manner, the tangential velocity of the tire where it meets the road is a little slower (or faster) than the relative velocity of the vehicle vs. the road itself, and the tire “slips”.
[0053] A vehicle safety system is most concerned with the sliding coefficient of friction, which will determine braking distance for a vehicle at a given mass and speed. The sliding (kinetic) COF is defined as μ k =F f /N where F f is the friction force between the vehicle and ground, N is the normal force (gravity) pushing the vehicle and ground together, and μ k is the COF. This is conceptually the same formulation as for a block sliding along a plane, as illustrated in FIG. 2 . A very slick surface will have μ k <<1, as the friction forces are very low. A tire on a high quality asphalt road will have a maximum COF of about 0.85.
[0054] When a vehicle is on a flat (non-inclined) surface, the force N=mg, where m is mass and g is gravitational acceleration. In some embodiments of the invention g=9.81 m/s, and in some embodiments of the invention g can be modeled or derived from a look-up table based on the exact location of the vehicle. The force N represents the force normal to the ground, and will change with the inclination of the vehicle. In some embodiments of the invention, inclination of the vehicle is measured or estimated using an inertial measurement system, which itself may include accelerometer(s), gyroscope(s), inclinometer(s), and/or magnetometer(s), where the information from the inertial measurement system is input into a model to calculate inclination. In some embodiments of the invention, inclination of the vehicle is further measured using global positioning system (GPS) data, which can infer inclination based on known topography of the roads, and can infer orientation based on known direction of travel and/or based on magnetometer measurements. In one embodiment, the inertial sensors are placed on a non-rotating member of the vehicle, such as on the front bumper. In some embodiments of the invention, inclination of the vehicle is measured using a bubble sensor. In any of these embodiments, the inclination is used to further inform the calculation of N and/or the calculation of COF.
[0055] In some embodiments of the invention the mass of the vehicle is estimated. In one embodiment, the mass is estimated based on a look-up table for the vehicle or is estimated using an optical imaging sensor which captures the size of the tire/ground interface for one or more tires. Based on the interface information and the known tire pressure as measured with the tire pressure measurement system, vehicle mass is calculated.
[0056] In some embodiments of the invention, COF is approximated using a formula that includes an input value a f , defined as the difference between the instantaneous tangential acceleration of the tire where it meets the road and the acceleration of the vehicle to which it is attached. Because the mass of the vehicle is a component of both the friction force and the normal force, these cancel each other and the value μ k =a f /g is directly measurable. In one embodiment, μ k =q*a f /g, where q is a fitting factor which may depend on factors such as vehicle inclination or other sensor measurements as discussed above.
[0057] In the above embodiments, forces are calculated using a “grey box” approach that relies on some first principles calculations. In another embodiment, COF itself or the component q are calculated using a “black box” approach that correlates COF with data derived from inertial and other sensors using a multivariable calibration fit approach without reliance on a specific physical model.
[0058] Measurements of slip are also useful for characterizing vehicle performance. Such measurements are performed in the vehicle using a device such as a hall sensor that is built into the wheel for this purpose as part of an ABS system. In one embodiment, the invention tracks GPS position over time to establish vehicle velocity as an input to model slip. In this embodiment, the tangential velocity of the wheel(s) is measured using a gyro or set of gyros attached to the wheel(s), and this is input into a model for the calculation of slip. In some embodiments, data from the accelerometer(s) is used as an input to improve the estimation of the velocity of the vehicle and/or wheel(s), where a velocity at time t n may be estimated based on knowledge of the velocity at a time t m and the acceleration a n-m during this time.
[0059] In one embodiment, measurements of both COF and slip are made using the same or overlapping sets of sensors. In another embodiment, slip may be inferred or calculated based on COF information. In one embodiment, data is received from inertial measurement sensors disposed on at least one rotating member, and on at least one non-rotating member. FIG. 3 shows an exemplary arrangement of sensors on a vehicle 300 , with a sensor or set of sensors 301 disposed on a wheel lug nut, and a sensor or set of sensors 302 disposed at the front bumper. FIG. 3 also shows an optional sensor or set of sensors 303 disposed on the windshield, which can be used for at least detecting precipitation. These locations represent one set of possible placement of sensors, and are not meant to be limiting.
[0060] The sensors are in wired or wireless communication with each other and/or with a central communications node (device), which may be inside or outside the vehicle, and which provides communication with the outside world. In one embodiment, communication between the sensors and the communications node is accomplished through Bluetooth LE. In one embodiment, a sensor may connect to a second sensor but not have a direct connection to the communications node, and in so doing, the sensors form a mesh network. Wireless communications systems may require antennas, and antenna placement, polarization, and directionality may be important for the application. In one embodiment, a sensor or communications hub is placed inside the vehicles windshield, where the signals satellite communications, GPS, infrastructure, and other sensors are unimpeded, or where the signal path to other sensors has the least obstruction (e.g., metal shielding). In another embodiment, the directionality, polarity, placement, and signal output timing of a wheel mounted sensor is chosen so as to improve the reception strength at another sensor, communications hub, or device (e.g. transmission occurs during periods when the hub of the wheel is not obstructing the signal as the sensor rotates with it).
[0061] FIG. 4 shows an exemplary system 400 that includes a wheel sensor 401 and a fixed sensor 402 , which are in data communication with a communications node 404 . To illustrate the potential use of a mesh network, the communications system 400 also includes an additional sensor(s) 403 which communicates to the fixed sensor(s) 402 , but not directly to the communications node 404 . The sensor 402 or 401 relays data from the sensor 403 back to the communications node using a wired or wireless connection. This may favorably save power in some configurations, depending on factors such as the distance of the sensors 401 - 403 from each other and from the communications node 404 . Note that this configuration is not meant to be limiting, merely illustrative. In one embodiment, a communications network might be established up from the individual sensors via BLE to the hub on one vehicle, via a cell network from that vehicle to the cloud, then through the internet and out via wifi connections of passing homes or businesses to a second vehicle, then between that vehicle and a third vehicle using Bluetooth or DSRC. In another embodiment, the houses or businesses might have sensor suites themselves, and pass information via wifi to the cloud, or via wifi or Bluetooth to passing vehicles. In yet another embodiment, roadside infrastructure (e.g. stop signs or streetlights) might be outfitted with sensors and/or communications hubs powered by photovoltaics, and communicate to the cloud via satellite internet, and to passing vehicles using DSRC or wifi.
[0062] The communications node 404 passes sensor data to an on-board processing module 405 which aggregates data from each sensor 401 - 403 . The communications node 404 may also be in contact with an external network such as a cellular network 407 , and may pass data via the cellular network 407 to a cloud database 408 and a cloud computing module 409 . The system of this invention may either use cloud computing module 409 or the on-board processing module 405 to process data from the sensors 401 - 403 and from the cloud components 408 , 409 . The on-board processing module 405 sends an alert to the driver via an output device(s) 406 if a threshold danger probability is reached. The output device(s) 406 includes audio, visual and/or tactile systems in the vehicle. In some embodiments, the on-board processing module 405 is configured with system memory, which may store the one or more profiles of the vehicle. In some embodiments, this stored profile(s) includes a family of COF vs slip ratio curves. FIG. 13 shows exemplary COF/slip profile curves for a vehicle for different road environmental conditions (e.g., dry pavement, wet pavement, compacted snow, smooth ice (i.e., black ice)). In some embodiments, the on-board processing module 405 is configured to retrieve profile information as an input into a model and/or for use with one or more inputs to, for example, make predictions about vehicle performance or estimations of environmental conditions.
[0063] In some embodiments of this configuration, the sensors 401 - 403 may send raw data to the communications node 404 or to each other. In some embodiments of this configuration, the sensors 401 - 403 further include onboard processing to reduce the data set and/or fuse information from one or more sensors, and thereby reduce the total communications overhead. The decision of whether to process the data on an on-board processor or send raw data to the communication node 404 depends on the relative power and bandwidth requirements of each mode of operation, and may differ for different sensors and/or locations of the sensors. Bluetooth Low Energy communication represents an exemplary communications operational mode, as it supports a star architecture, with the central device able to connect many peripheral devices, and supports over-the-air updates. In one embodiment, devices coordinate to “sleep” between short transmissions, significantly reducing power use. Alternatively, information may be stored and transmitted in bursts on higher-bandwidth, higher power-use devices such as standard Bluetooth or wifi. In that case, these devices may be powered down between bursts of transmission to save power.
[0064] In one embodiment, communications are accomplished through means other than radio frequency transmission, including wired transmission, optical transmission, acoustic transmission, magnetic induction, or transmission of electrical signals through the body of the vehicle, or through the vehicles on-board diagnostics (OBD), etc.
[0065] In one embodiment, one or more of the sensors 401 - 403 , on-board processing module 405 , and communications systems 404 are powered by scavenged power (also known as power harvesting or energy scavenging). Energy is derived from external sources constantly during use, or is derived intermittently and stored on battery, capacitor, super capacitor, etc. Example power sources include solar cells, kinetic energy devices that derive power from vibrational, rotational, linear, or other motion of the vehicle, or a harvesting ambient radiation source device (e.g., antenna collection of energy from radio waves, such as in a Powercast system, or via wifi or DSRC power scavenging). In one embodiment, a radio source is provided in the vehicle to create radio waves which are harvested by the sensors. In one embodiment, the sensors are equipped with Piezoelectric, Pyroelectric, Thermoelectrics, Electrostatic (capacitive), Magnetic induction, Mechanical, or Micro wind turbine energy harvesting capability. In one embodiment, a magnetic induction or piezo element is included in a sensor pack to harvest vibrational energy. In one embodiment, the rotation of the tire causes a magnet to move due to changing gravitational field and/or centripetal forces, inducing power in a coil for use in the system.
[0066] The system 400 may optionally include a memory device (or devices) 410 that stores information (wheelbase, tire types, deceleration/acceleration capabilities, etc.) pertaining to the host vehicle, or stores data when communications are interrupted or non-existent The processing module 405 uses stored information to generate profile information (described later). The memory 410 may also store raw and/or processed sensor information, road type/condition information and weather information. The road type/condition information and weather information as well as other information are received at the system 400 from an external source via the communications node 404 .
[0067] FIG. 5 shows a lug nut sensor 500 that is to be attached to a vehicle wheel. In this embodiment, the lug nut sensor 500 includes a screw 501 which threads through a tire package cover 502 to unite with a sensor package housing 506 and the lug nut 507 . The housing 506 includes two lithium polymer batteries 503 , an inertial measurement unit 504 having an accelerometer and gyroscope, and a microprocessor 505 with Bluetooth communications capability. In one embodiment, the accelerometer includes one 6 g 3-axis accelerometer with axes pointing radially, laterally, and tangentially with regard to the tire. In one embodiment, the sensor system 500 includes one additional 120 g one-axis accelerometer for direct measurement of radial accelerations at high speeds. In one embodiment, the microprocessor 505 calibrates the sensor, samples data, and filters it to produce measurements in radial, tangential, lateral axes of the tire. Such calibration is a typical sensor fusion application—e.g. gyros are prone to drift, but this can be compensated for in a full inertial measurement unit. Velocity measurements made using gyros on the tires can be undrifted GPS or accelerometers, etc. This sensor may of course alternatively be affixed to the outside of the vehicle wheel (e.g. using two-sided tape) or to the inside of the vehicle (e.g. attached to a band running along the inside of the hub).
[0068] To calibrate the tangential acceleration (y) measurement, in one embodiment the following approach is used:
1. At constant speed and perfect alignment, tangential acceleration (y) is 0; 2. Define calibrated x as positive to the “east” and calibrated y as positive to the “north”; and 3. At constant speed with misalignment angle θ, defined as a rotation of the system counterclockwise from x and y to x u and y u , the calibrated x and y are
[0000] x=x u cos(θ)+ y u sin(θ)
[0000] y=y u cos(θ)− x u sin(θ).
[0072] In one embodiment, the effects of gravity are averaged out by taking hundreds or thousands of measurements of x u /y u to obtain average measurements x u — avg and y u — avg . At constant velocity, y=0, and thus y u — avg ≅x u — avg tan(θ), such that it is possible to calculate θ=atan(y u — avg /x u — avg ).
[0073] In one embodiment, tangential acceleration is determined by sampling acceleration data at >30 Hz, with a predefined rate of sampling (e.g., 250 Hz). In this embodiment, over a (for example) time of measurement, the max and min values of (calibrated) y are identified, which will roughly correspond to acceleration up and acceleration down, and which will vary by +1 g and −1 g from true acceleration. These measurements are averaged to cancel out the effects of gravity to obtain a tangential acceleration estimate. This value is updated to the processor node, and the measurement process is repeated.
[0074] In another embodiment, tangential acceleration is calculated using a Kalman filter algorithm. In an exemplary process, lug nut tangential acceleration is defined as being proportional to tire/road contact point tangential acceleration—if R eff is the effective radius of the tire (measured from tire axel to road), and R hub is radius of hub to lug, then wheel tan — acc =R eff /R lug lug tan — acc +k, where k is a cyclical component due to gravity. The constants R eff and R lug are set using system identification or a calibration scheme. A Kalman filter which estimates the tire position and velocity—and thus the direction of gravity—is used to filter out the cyclical acceleration components due to gravity and to noise.
[0075] In another embodiment, a commercially available 6-axis sensor (x, y, and z axis accelerometer and x, y, z axis gyroscope on the same silicon chip), is used to directly measure the orientation and angular velocity of the tire. Most such chips are (presently) limited to perhaps 16 g accelerations and 2000 degrees per second. Mounted even a few centimeters from the hub of the wheel (example near a lug nut), a vehicle traveling at highway speeds would saturate an accelerometer channel pointed along the radial axis, and a gyro revolving around the lateral one. This limits the ability to determine the angular velocity of the tire (and thus linear velocity of the vehicle). However, in one embodiment the axis of measurement is offset to reduce the magnitude of both the acceleration and angular velocity measured. This creates a very straightforward linear reduction in the measurement of the angular velocity if the vehicle is going straight, but creates a complex relationship between the angular velocities of the other axes when the auto is turning. Similarly, this can create a very straightforward linear reduction in the measurement radial acceleration (which can be used to estimate the angular velocity) if the vehicle is going straight, but creates a complicated relationship between the angular acceleration of the tire and the estimated angular velocity, and changes the relationship between the position components of the acceleration in the offset radial and tangential measurements. In some embodiments, these complexities are resolved through further processing in a grey box or black box model.
[0076] FIG. 6 shows one embodiment of a wheel assembly 600 where a wheel inertial measurement sensor pack 605 is mounted at or near a tire pressure measurement sensor 601 in proximity to a valve stem 602 on a wheel 604 . The sensor pack 605 is connected by a valve stem retainer screw 603 , or alternatively is fixed in position by an adhesive.
[0077] In an alternate embodiment, the sensor set is affixed to the back of the wheel using an adhesive—the specific location can vary in implementation. In some embodiments, an antenna is added to the sensor system in order to improve communication capability with the communication node. In some embodiments, the tire stem is used as the antenna.
[0078] FIG. 7 shows a suite of sensors system 700 disposed on the front bumper. The system 700 includes a bumper sensor suite housing 701 , a power switch 702 , and a charge controller and voltage regulator 703 which controls charging of a battery pack 705 by a solar panel 704 . The solar panel 704 provides power to the system, and may also usefully measure insolation power levels in real time, and therefore may also be used as a sensor. Other embodiments may utilize other power sources. The system 700 further includes a Bluetooth modem 706 and a microcontroller 707 , which may be housed in the same package (e.g., a system on a chip) or in different packages. The system 700 may optionally include an infrared thermometer 708 and/or a microphone 709 , as well as an inertial measurement unit (IMU) 710 . A cover 711 protects the components of the system 700 .
[0079] In one embodiment, the sensors of the system 700 identify road surface type (e.g., concrete, asphalt, gravel, dirt), condition (e.g., worn, cracked, potholed), and covering (e.g., black ice, lose or packed snow, slush, rain, dirt, etc.). In one embodiment, the sensor(s) measure ambient temperature and/or relative humidity. In one embodiment, the IR sensor(s) 708 measure temperatures in front of the front tires. The microphone sensor 709 measures sound that is analyzed by a processor to quantify road noise, which may be correlated to weather conditions. The IMU 710 includes accelerometers, gyroscopes, inclinometers, and/or magnetometers. In one embodiment, the sensors additionally include optical image sensor (not shown) that provides imaging data that is used by a processor to quantify visibility, particulate counts, cloud cover, etc. In one embodiment, this status of the headlights is determined using sensors.
[0080] FIG. 8 shows an embodiment of a sensor that is attached to or near a windshield of the vehicle. The system 800 includes a housing 801 , a charge controller and voltage regulator 802 , sensor circuitry 803 , a sensor battery pack 804 , and a solar panel 805 . The solar panel 805 provides power to the components, and may also usefully measure insolation power levels in real time, and therefore may be used as a sensor as well. The system 800 further includes a Bluetooth modem 807 and a microcontroller 806 , which may be housed in the same package (e.g., a system on a chip) or in different packages. The system 800 may also include a capacitive sensor 808 and/or a swept frequency sensor 809 , as well as an optional ambient light sensor 810 . The system components are protected from the environment by a bottom level decal 811 . Attaching sensors inside the vehicle (e.g. inside the passenger compartment, tire, or engine housing) may serve to protect the sensors from extremes of temperature, UV, humidity etc. The sensors may alternatively/additionally be protected using superominphobic coatings for lenses, cases etc.
[0081] Information gathered by the system 800 includes precipitation detection, fog, rain, snow, ice, visibility and cloud cover, and/or windshield wiper frequency. The system 800 can be mounted inside or outside of windshield glass. Mounting the system 800 inside will increase the package's life.
[0082] In one embodiment, the swept frequency sensor 809 includes a Swept Frequency Inductive Precipitation Sensor, such as that previously described in U.S. Pat. No. 6,388,453 B1. While '453 describes the use of sine wave sweeping to obtain a response, signals besides sine waves are used—for example, a complex frequency chirp is sent, and a controls theory/signal processing method called an empirical transfer function estimator (ETFE) is applied to determine transfer function. The empirical transfer function estimate is computed as the ratio of an output Fourier transform to an input Fourier transform, using a fast Fourier transform (FFT). The periodogram is computed as the normalized absolute square of the Fourier transform of the time series. Smoothed versions can be obtained by applying a Hamming window to the output FFT times the conjugate of the input FFT, and to the absolute square of the input FFT, respectively, and subsequently forming the ratio of the results.
[0083] In an alternative embodiment for sensing of wiper frequency or precipitation, a light source such as a laser is shone onto the windshield at an angle below (or above) the Brewster's angle of the glass while dry. Precipitation causes a change in the optical index system such that the light now is above (or below) the Brewster's angle. Then when the wiper blade cleans the glass, the system briefly reverts, allowing detection of both the precipitation and the wiper activation via this optical sensor.
[0084] In one embodiment of the invention, the precipitation sensor measures amount or rate of precipitation. In another embodiment of the invention, the precipitation sensor measures type of precipitation, for example by changes in light scattering associated with snow. In another embodiment of the invention, precipitation type is inferred based on a combination of sensor measurements and/or information from weather sensors external to the vehicle.
[0085] When the vehicle is operating, both slip and COF are calculated continuously as the vehicle runs based on a data set including at least data from the wheel-mounted IMU and the fixed IMU. If the environment were always constant, this information could be used to define a curve showing the relationship between COF and slip. However, because road conditions change as the vehicle moves, there is no single curve defining the performance of the vehicle, and a profile of curves is built.
[0086] In one embodiment, vehicle environmental conditions are separated by separating COF vs slip ratio data into different clusters of performance, using a technique such as K-means.
[0087] In a further embodiment, this data on COF vs slip ratio is added to a database alongside further information including time, location, traffic, road type, and/or environmental conditions local to the data capture event. Road conditions are quantified based on an estimated risk associated with the known road type, for example scoring 1=dirt road, 5=highway, etc. In one embodiment, road conditions are quantified based on a score derived from COF measurements made by multiple vehicles. Environmental conditions are quantified on one or more axis to enhance mathematical processing of the data. For example, environmental conditions may be scored in terms of ambient temperature (for example, in ° C.), road temperature (for example, in ° C.), insolation power (for example, in W/m 2 ), precipitation intensity (for example, in cm/hr), etc. In some embodiments, an aggregate environmental score is compiled based on the hazard implied by different environmental elements. In one embodiment, an aggregate environment score is compiled with information about known road type and known environmental conditions. For example, a bridge may receive a high composite score under warm, sunny conditions, but may receive a dramatically lower score under cold, snowy conditions.
[0088] Elements of the database which are measured in high confidence may be usefully employed to identify more accurate values for elements of the database which have lower confidence. In one embodiment, a measured COF or slip value may be used to estimate an environmental condition, or a known environmental condition may be used to estimate a COF or slip value.
[0089] In one embodiment, measurements of COF and slip in known good environmental conditions (e.g., warm and sunny) is combined to create a curve for the vehicle that is generally accurate for good environmental conditions, thus eliminating the previously stated difficulty of clustering data automatically. FIG. 9 shows a system that builds a profile, where information from wheel inertial sensors 901 , the fixed inertial sensor 902 , and optionally the GPS 903 are transferred to a COF/slip computational module 904 , which calculates the local COF and slip ratio associated with this set of sensor data. This information is transferred to a vehicle profile calculator 906 , which fuses the COF and slip ratio information with information from an environmental database 905 and/or GPS data to create a profile for the vehicle. This information may optionally be transferred to an on-board vehicle profile database 907 and/or a vehicle profile database 908 in the cloud.
[0090] In another embodiment, measurements of COF for a vehicle is used to successfully identify adverse environmental conditions such as black ice. In this way, hyper-local environmental changes such as icing are easily identified by examining the COF performance of the vehicle after a profile has been created. FIG. 10 shows a system that estimates environmental conditions, where information from wheel inertial sensors 1001 , the fixed inertial sensor 1002 , and optionally a GPS 1003 are transferred to a COF/slip computational module 1004 , which calculates the local COF and slip associated with this set of sensor data. This information is transferred to an environmental conditions computation module 1005 , which fuses the COF and slip information with information from the vehicle profile 1006 and/or GPS data to estimate environmental conditions for the vehicle. This information may optionally be transferred to an environmental profile database 908 in the cloud, where it may be usefully applied to warn other drivers of adverse weather conditions in the GPS location where the measurement was taken.
[0091] Such a warning system is described in FIG. 11 . In this embodiment, information on the vehicle location from a GPS 1102 and optionally from a trip path module 1101 is fed into a vehicle location prediction module 1103 , which predicts the future locations of the vehicles during the trip. This information is fed into an environmental prediction model 1105 alongside environmental profile information from a database 1104 from the cloud. The environmental profile information includes data from the national weather service, local sensors, and/or data collected by other vehicles using the system described in FIG. 10 above, as well as other mobile vehicle weather collection processes. The environmental prediction information is passed to a vehicle warning module 1107 , which compares the environmental prediction with the vehicle COF/slip profile to identify whether the predicted environment will be outside the suggested operating specification for a vehicle with that profile. If a threshold is passed, this information is sent as a warning to an interested party 1108 . An interested party includes a driver, or a fleet owner, or an insurance operator, etc.
[0092] Information, guidance, and warnings may be provided in many ways, including via smart phone or watch (e.g. alarm bells, vibration, texts, phone calls, via traffic apps, text to speech, satellite communications system such as OnStar, and visual cues), as well as visually or auditorially through the vehicle's OBD display, navigation display or text to speech system, radio/entertainment console, vehicle or aftermarket heads up display, DSRC warning system, and many other means. In one embodiment, the information, guidance, and warnings are delivered via text to speech or heads up display to preserve driver concentration the road, In another embodiment, the warnings are integrated with the vehicles safety system to take action if the driver does not. In another embodiment, the information, guidance and warnings are delivered to a self-driving vehicle, so that the vehicle or driver may take appropriate action. In another embodiment, the guidance takes the form of a safe or advised driving speed, or warning to slow down. In another embodiment, the driver or navigator uses voice commands to request information, guidance, or warnings. In another embodiment, the warnings take the form of an escalating series of warnings with regard to weather, safe driving speed, safe stopping distance, or road conditions.
[0093] One novel thing element is that, before the weather moved and the (often sparsely located) sensors stayed still, the presented system uses moving mobile sensors that can send information machine-to-machine (M2M). The combination of mobility and M2M creates a “crowd-sourced” mobile sensor “fabric”, and the fabric is constructed such that most information is both generated and consumed where there are the most users and sensors. Individual people may perceive changing clouds and precipitation in one area, but networked and fused sensors see changes in pressure, irradiance, humidity, and precipitation rates over large areas, as well as have access to historical weather and data patterns, and thus the whole system is able to do analysis and prediction different in kind rather than degree.
[0094] In one embodiment, a plurality of sensors send to a smartphone acting as a hub, which aggregates, organizes, fuses and/or prepares information; a plurality of smartphones, posts that information to a collection system, where it is quality control checked; a buffering system stores and prioritizes and organizes the data in queues; the data are then fused with existing data such as weather, road, GIS, databases, to create a current situational picture; these situational pictures are made available using (for example) geofencing techniques, both to alert and organize data about motorists and geographic areas; geofencing implies that now we can follow up with a set of triggers, these triggers being assigned to mobile entities, based on fused criteria, indicating desired alerts based on individual preferences.
[0095] Additionally, such a machine-to-machine system is able to return information back quickly and per user preferences—the system can have “smart triggers”. A simple temperature gauge may alert a user with a red light when the temperature goes below a set value, but a smart trigger seeks information and makes warnings that are context sensitive—such as warning as user about how the confluence of the rate of decrease in pavement temperature and predicted precipitation may generate frozen pavement. Using modern software technologies like Pagerank or Twitter that look for important signals using eigenvectors, these signals can result in information, guidance, or warnings routed to a unique user by indexes to the most important links in the eigenvector in a very fast manner. In such a system, metadata is fused together, an eigenvector analysis is run, then indexed the most important events, making it lightning fast to both find the smart triggers and/or users. This can provide fast M to M alerts—in one embodiment, machines automatically spraying salt on a road that will soon require it, or lower barricades on roads that may soon experience white out conditions, or trigger road signals warning of black ice, all in a very fast and automated manner, scalable to huge numbers of users and triggers.
[0096] Use cases for the user criteria of such a system include: soccer mom's criteria is whether she can drive 3 miles safely in the small geofenced area between home and practice; a medium-haul limo service will look at a larger geofenced area, and want fused information about traffic, weather, known pick up sites, and historical patterns in order to make the most efficient run; maintenance and logistics organizations will want to watch vehicles roll over road segments to see what needs repair or where slowdown may be predicted to occur—their user criteria may be real-time analysis, or it may be a forecast about the desirability of salting an iced road in the next four hours, paving a bumpy road in the next four months, or allocating a budget for the next four years; long hall trucking businesses may wish to add weather and road condition forecasts to the fleet management and fleet routing services that are commonly employed by such concerns.
[0097] The availability of the various information available to such a system may be used in novel ways. For instance, unique signals can be created which may be analyzed using advanced mathematical and analytical techniques, identifying conditions, and forecasting conditions in ways that were previously unavailable (e.g., machine learning algorithms with novel features for weather knowledge and actionable information, and neural networks provide logistic regression outputs not previously available do to the scarcity of information about road weather conditions).
[0098] A method of using this data may for example include receiving tire slip information and/or COF information from vehicle sensors; receiving one or more external environmental conditions information from a database; receiving a route request having at least route information and time of departure information; generating safety values for a plurality of portions of the requested route based on the received environmental conditions information and previously stored vehicle performance information associated with the route request; determining if the generated safety values meet at least one of a predefined safety threshold or a time of travel threshold; if the determination indicates that one of the safety values fails to meet the at least one safety threshold or the time of travel threshold, generating at least one of a new route or a new time of departure that would cause the generated safety values to meet the safety threshold or the time of travel threshold; and presenting the generated new route or new time of departure to a user or interested party associated with the route request. In one embodiment, the database data includes COF/slip information collected from a plurality of sensors located on a plurality of ground vehicles.
[0099] As noted, vehicle sensor and/or profile information may be usefully combined into a vehicle library or database in the cloud. This library or database will allow estimation of COF/slip performance in weather and/or road conditions for a specified vehicle, even if that vehicle does not have a profile that extends to the current environmental and/or conditions, by comparing this specified vehicle with other vehicles with similar properties and/or using sensor outputs from other vehicles. Similar properties may include, but are not limited to, similar model/make, similar tires, similar number of miles on the tires, similar profiles in measured weather conditions, COF measurements of vehicles traveling over current trip path of a vehicle, etc.
[0100] Such a process is shown in FIG. 12 , where sensor measurements and/or profiles from multiple vehicles 1201 , 1202 , 1203 , etc. are combined into a library 1204 . In such an arrangement, a vehicle with an incomplete profile 1205 does not necessarily have measured data that correlates to the specific weather conditions. As a result, its performance can be estimated by the vehicle prediction module 1206 by extrapolating from data for similar vehicles profiles in the library.
[0101] In one embodiment, a vehicle may receive information from the cloud based database (or other wirelessly accessible database) for use with vehicle profile information. For instance, FIG. 14 illustrates an expected travel path of a vehicle traveling between first and second locations (e.g., Idaho Springs, Colo. and Silverthorne, Colo.). Such an expected travel path may be inferred based on a current travel direction of a vehicle, previous user information, or entered by a user. The database may provide information for the expected travel path to the vehicle. In this regard, the database may include measurements and/or profiles of vehicles having previously traveled over the expected travel path. Such information may be for vehicles that have traveled over the expected travel path within a predetermined time period (e.g., previous fifteen minutes, hour, six hours, day etc.) In the present embodiment, the database may provide prior COF information/measurements of vehicles passing over the travel path. In this regard, prior COF information 1402 may be provided for predetermined road segments (e.g., every quarter mile) and/or for changes in road geography, surface and/or road structure (e.g., changes in road grade, changes from asphalt to concrete, changes from new asphalt to worn asphalt, bridge susceptible to icing, etc.). This is illustrated on the map shown in FIG. 14 which shows prior COF information 1402 that is provided for different segments of the travel path.
[0102] The prior COF information for the travel path may be determined in any manner from previously reported COF information. For instance, the prior COF information may be an average of all COFs reported by vehicles having previously passed over all or portions of the travel path. Any other mathematical representation (e.g., mode, mean etc.) of the prior COFs may be provided. The prior COF information may be further analyzed based on, for example vehicle type. In this regard, the type of vehicle on the travel path may be known and the vehicle may request or otherwise receive COF information for like vehicles: rear wheel drive vehicles, small all wheel drive, large all wheel drive, trucks, etc. That is, prior COF information for like vehicles may be provided along the travel path.
[0103] Upon receiving prior COF information, the vehicle may correlate the prior COF information for upcoming segments with the profiles 1302 a - n stored in the on-board vehicle profile database 907 . Alternatively, the vehicle may access stored profiles from the cloud based database 908 . See FIG. 9 . The cloud based profiles may be generated by the subject vehicle or may be profiles of other like vehicles. In any arrangement, the vehicle profile computation module 906 may utilize the prior COF information with the profiles 1302 a - n to determine the expected performance of the vehicle on the upcoming road segment. For instance, an expected wheel slip percentage may be calculated.
[0104] As shown in FIG. 13 , using the prior COF information as an input with the profiles 1302 allows for determining an expected slip percentage if the environmental conditions of the road segment is known or determinable. Such environmental conditions may be determined using sensors of the vehicle. Alternatively, prior environmental conditions 1404 may be provided to the vehicle with the prior COF information. See FIG. 14 . Stated otherwise, the library may, in addition to providing prior COF information, provide prior environmental information 1404 as reported by previous vehicles passing over the expected travel path. More generally, the library may provide road surface information (e.g., COF information and environmental information) to the vehicle. In either case, the vehicle traveling on the travel path may utilize the COF information and/or environmental information with stored profiles (See FIG. 13 ) to determine performance/safety information for the vehicle prior to the vehicle passing over upcoming segments of the travel path.
[0105] Based on the estimated wheel slip of the vehicle, various outputs (e.g., predictions) may be provided to the driver of the vehicle and/or to the control systems of the vehicle. For instance, if a slip percentage for an upcoming road segment exceeds a predetermined threshold, a warning output may be generated. In a further arrangement, an alternate route 1502 may be suggested if a slip percentage for an upcoming road segment exceeds a predetermined threshold. See FIG. 15 .
[0106] FIG. 16 illustrates a process 1600 for utilizing prior road surface information at a vehicle. The process begins with the establishing 1602 of a wireless connection between a vehicle and a road surface database. Once communications exist between the vehicle and the database, the vehicle may request and/or receive 1604 road surface information from the database for a travel path of the vehicle. In some instances, the database may be operative to push data to the vehicle without a request originating from the vehicle. That is, if conditions warrant providing data, the database may initiate contact and/or automatically provide data to a vehicle. The road surface information typically includes COF information for one or more segments of the travel path. The road surface information may further include environmental information for the one or more segments of the travel path. An on-board processor of the vehicle then accesses 1606 one or more profiles of the vehicle. Such access may be from local storage or via the wireless connection. Using the road surface information and the profile(s), the processor is operative to calculate 1608 estimated wheel slip for one or more upcoming segments of the travel path. If one or more of the wheel slip estimates exceed a predetermined threshold(s), an output may be generated 1610 for receipt by the driver of the vehicle and/or vehicle control systems. Such driver outputs may be related to speed reduction recommendations and alternate route suggestions among others.
[0107] FIG. 17 illustrates a process 1700 for gathering and distributing road surface information. Initially, a processing platform/database receives 1702 road surface reports from a plurality of vehicles traveling over roads. These road surface reports typically include COF information determined by the vehicles along with location information identifying where the COF information was determined. The road surface reports may also include environmental information measured directly or from which environmental information for the location may be determined (e.g., in conjunction with a weather model). The processing platform processes and stores 1704 information from or derived from the road surface reports. At a subsequent time, a request for road surface information for a travel path is received 1706 from a vehicle or the processing platform determines a vehicle is traveling a travel path for which pertinent road surface information is available. In the latter regard, the processing platform may be receiving road surface reports from a vehicle and if no adverse road conditions are known, not information may be provided. Conversely, if upcoming road conditions are determined adverse (e.g., COF for a road segment drops below a predetermined threshold) information may be pushed to the vehicle absent a request from the vehicle. In any case, stored road surface information is then processed to identify 1708 prior road surface information for the travel path. The identified road surface information is then sent 1710 to the requesting vehicle.
[0108] The modules 904 , 906 , 1004 , 1005 , 1101 , 1103 , 1105 , 1107 , and 1206 and/or processes described in relation to FIGS. 9-12 and 16 - 17 are processing functions that may be performed by processors located at one or more of the locations such as the lug nut, bumper or windshield systems, or at a processor located on-board or off-board the vehicle.
[0109] The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art can be made within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art. | Systems and methods for obtaining data about road conditions as they pertain to an individual vehicle, using this information to build a model of vehicle behavior as a function of its environment, and aggregating information concerning multiple vehicles along with data from other sources in order to predict vehicle behavior in future environments. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
A related application is application Ser. No. 11/107,556, filed concurrently herewith for “Wideband Temperature Variable Attenuator,” the disclosure of which are incorporated herein by reference.
FIELD OF INVENTION
The present invention relates to a voltage controlled attenuator (VCA) for RF (radio frequency) and microwave applications that is free of intermodulation distortion. More particularly, the present invention relates to an attenuator that is controlled based upon temperature and does not include active devices.
BACKGROUND OF THE INVENTION
VCAs are a fairly common element of almost any RF or microwave circuit. Their function is to change the amplitude of a signal based on some external signal, usually a voltage or current. A common use is the leveling of a signal so that both strong and weak signals can be adjusted in amplitude to provide a constant level signal to the next stage of the circuit. Another use is the balancing of multiple signal paths so they all have the same gain. A third use would be to use a VCA to control the gain of an amplifier over temperature by varying the control voltage based on a measurement of the ambient temperature. This last use is to counter undesired changes to the gain of the amplifier when the ambient temperature changes.
The vast majority of presently available VCAs include either diodes, transistors, or FETs (field effect transistors). These active devices have non-linear transfer characteristics which result in distortion to RF and microwave input signals. This causes additional and unwanted signals to be generated which are not present in the original signal. For example, suppose two people are transmitting a signal (from a cell phone, for instance) on two different frequencies at the same time. If the two signals were applied to a non-linear device, several additional signals would be generated that would be on frequencies that are different from the original two frequencies. This is known as intermodulation distortion. These additional signals have the potential of causing interference to other services, like police or fire departments that use the same frequencies as the additional signals.
VCAs are designed to reduce intermodulation distortion to the smallest possible value, but due to the non-linear characteristics of the control devices used, there is no way to eliminate intermodulation distortion entirely. Therefore, there exists a real and present need for a VCA that can control the amplitude of an RF or microwave signal without generating any distortion products which result in intermodulation distortion.
U.S. Pat. No. 5,332,981, issued to Joseph B. Mazzochette, et al., issued Jul. 26, 1994, entitled “Temperature Variable Attenuator,” which is incorporated herein by reference, describes an attenuator that includes temperature variable resistors (thermistors) in the attenuating path. As shown in FIGS. 1A and 1B which are reproduced from FIGS. 1 and 3 of the '981 patent. conventional attenuators include a Tee attenuator 10 comprising a pair of identical series resistors R 1 and a shunt resistor R 2 and a Pi attenuator 12 comprising a series resistor R 2 and two shunt resistors R 1 and R 3 . FIG. 1 C is a plot reproduced from FIG. 2 of the '981 patent, showing a family of constant attenuation curves from 1 to 10 dB and a constant 50 ohm impedance curve descending from the upper left of the plot to the lower right. The vertical axis on this plot represents the value of shunt resistor R 2 in the T attenuator 10 and the horizontal axis represents the values of series resistors R 1 . The point of intersection between the 50 ohm impedance curve and an attenuation curve gives the value of R 1 and R 2 that produce the attenuation represented by the attenuation curve and a 50 ohm impedance match.
In the temperature variable attenuator of the '981 patent, the temperature coefficient of resistance (TCR) of at least one resistor is different such that the attenuation of the attenuator changes at a controlled rate with changes in temperature while the impedance of the attenuator remains substantially constant. Thus, this device changes its attenuation based on the ambient temperature, but because it is constructed entirely of passive components it does not generate any intermodulation distortion. However, the attenuation of this device cannot be set to a predetermined value based upon a constant external voltage or current.
U.S. Pat. No. 5,999,064, issued to Robert Blacka, et al., issued Dec. 7, 1999, entitled “Heated Temperature Variable Attenuator,” which is also incorporated by reference, provides a heater in a temperature variable attenuator. The heater allows an external voltage or current to heat the thermistors that are part of the attenuating circuit to affect their resistance, and thus, the attenuation of the device. However, there are a number of limitations with this device which reduces its usefulness as a VCA.
SUMMARY OF THE INVENTION
The present invention is a VCA for RF and microwave applications that is free of intermodulation distortion. In a preferred embodiment, the present invention has at least first and second thermistors, arranged into a classical Tee, Pi, or Bridged Tee attenuator design, a heating element, a temperature sensor, and a control circuit. The thermistors have different temperature coefficients of resistance and are in close proximity to the heating element and the temperature sensor. The control circuit receives a voltage signal from the temperature sensor, compares that signal with a voltage signal specifying a desired temperature, and applies electrical energy to the heating element until receiving a signal from the temperature sensor that the temperature of the thermistors matches the desired temperature. As a result, the attenuation of the attenuator can be changed at a controlled rate by varying the temperature of the thermistors, while the impedance of the attenuator remains within acceptable levels.
In one embodiment, the temperature coefficient of resistance of one thermistor is zero. In another embodiment, the temperature sensor is also a thermistor. In yet another embodiment, the temperature sensor is a resistance temperature detector.
In a particular embodiment, the attenuator is constructed using thick-film or thin-film resistors that vary their resistance over temperature. In yet another embodiment, the thick-film or thin-film resistors are deposited onto a substrate of aluminum oxide, aluminum nitride, beryllium oxide, CVD diamond, or epoxy-glass laminate.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features, and advantages of the invention will be more readily apparent from the following detailed description in which:
FIGS. 1A–1C depict aspects of prior art temperature variable attenuators;
FIG. 2 is a schematic diagram showing the basic structure of an attenuator in accordance with the present invention
FIG. 3 is the top view of an embodiment of the present invention;
FIG. 4 is the top view of a heating structure in the embodiment of the present invention shown in FIG. 3 ;
FIG. 5 is the side view of the embodiment of the present invention shown in FIG. 3 ;
FIG. 6 is a graph depicting the attenuation produced at given temperature in an illustrative embodiment of the invention;
FIG. 7 is a circuit diagram showing the basic structure of a control circuit of an embodiment of the present invention; and
FIGS. 8A–8N are top views illustrating the sequence of steps in the formation of the attenuator of FIGS. 3–5 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 is a schematic diagram of an illustrative attenuator 200 of the present invention. Attenuator 200 includes a pair of identical series thermistors 204 and shunt thermistor 206 . These thermistors are arranged in a classical Tee attenuator design. The attenuator also includes temperature sensor 202 and heating element 208 . Thermistors 204 and 206 are arranged relative to heating element 208 and temperature sensor 202 such that they are simultaneously heated by heating element 208 , and their temperature is detected by temperature sensor 202 .
A physical embodiment of the attenuator of FIG. 2 is shown in FIGS. 3–5 . FIG. 3 is a top view of attenuator 300 , FIG. 4 is a top view of a heating structure 400 of the attenuator and FIG. 5 is a side view. As shown in FIG. 5 , attenuator 300 is formed on substrate 500 . Substrate 500 is an insulating material such as aluminum oxide (alumina), aluminum nitride (ALN), beryllium oxide (BeO), CVD diamond, or epoxy-glass laminate. A ground plane 501 of platinum, silver or a platinum silver alloy is formed on one side of substrate 500 . Optionally, a dielectric layer 502 is formed on the opposite side of substrate 500 . Heating structure 400 is formed on dielectric layer 502 , if present, or on substrate 500 . As shown in the top view of FIG. 4 , heating structure 400 comprises a dielectric layer 502 in which are formed heater contact areas 404 , 406 and a U-shaped heating element 408 . Heating element 408 is positioned such that it electrically extends between and contacts first and second heater contact areas 404 and 406 . As best shown in the side view of FIG. 5 , a layer of insulating material 320 covers most of heating element 408 but not contact areas 404 , 406 .
Temperature sensor 202 and thermistors 204 and 206 are realized in the implementation of FIGS. 3–5 as sensor 316 and thermistors 310 and 312 which are formed on insulating material 320 . Thermistors 310 and 312 are each positioned to extend at least across a portion of heating element 408 . The thermistors are electrically connected to each other at node 311 , thermistors 310 are electrically connected to contact areas 314 and thermistor 312 is electrically connected to contact area 322 . Contact area 322 is connected to ground plane 501 on the underside of substrate 500 by a ground wrap connector on the outside of the substrate or by a via through the substrate. Temperature sensor 316 is positioned so that it is in close enough proximity to thermistors 310 and 312 to detect their temperature and is an electrical contact with first and second sensor contact areas 318 and 319 .
The attenuating characteristics of attenuator 300 as a function of temperature can be determined simply by measuring them over the operating range of the attenuator. For example, in an illustrative embodiment of the inventory, the variation of attenuation with temperature might be determined to be that shown in the graph of FIG. 6 . Once this functional relationship is known, any attenuation over the operating range of attenuator 300 can be selected by accurately controlling the temperature of thermistors 310 and 312 so as to achieve the attenuation known to correspond to that temperature. This temperature control is accomplished with external circuit 700 of FIG. 7 which constantly monitors the device temperature with temperature sensor 202 / 316 and controls the heat output from heating element 208 / 408 .
Circuit 700 comprises an operational amplifier 710 having an inverting input connected to the node between an input resister R 1 and a feedback resistor R 2 and a noninverting input connected to the node between resistors R 3 and R 4 in a voltage divider network 720 . The resistances of R 1 and R 3 are equal and the resistances of R 2 and R 4 are equal. Input resistor R 1 is connected to a node in a temperature sensing circuit 730 comprising temperature sensor 202 / 316 and resistor R 5 . The voltage at this node is V 1 . The voltage applied to voltage divider 720 is V 2 . As a result, operational amplifier 710 functions as a differential amplifier that receives at its inverting and non-inverting terminals, respectively, signals proportional to V 1 and V 2 and produces an output signal
V out = R1 R2 ( V2 - V1 ) .
The output of operational amplifier is applied to a transistor 740 in a heating circuit 750 comprising transistor 740 and heating element 208 / 408 .
For the circuit shown in FIG. 7 , temperature sensor 202 / 316 has a negative temperature coefficient of resistance (TCR). As a result, as the temperature rises, voltage V 1 increases monotonically. Voltage V 2 specifies the desired operating temperature of the attenuator. Thus, the output of the operational amplifier is a signal proportional to the difference between the desired operating temperature and the actual operating temperature; and this signal is used to control the current flow in heating circuit 750 such that the amount of current flow is a function of the difference between the desired temperature and the actual temperature. Since the current flow through the heating circuit increases the temperature sensed by temperature sensing circuit 730 , this increases V 1 and thereby decreases the difference (V 2 −V 1 ) until the temperature sensed by the temperature sensing circuit reaches the temperature specified by voltage V 2 .
Alternatively, circuit 700 would function in the same way if the positions of sensor 202 / 316 and resistor R 5 in the temperature sensing circuit were interchanged and if sensor 202 / 316 had a positive TCR.
FIGS. 8A–8N are top views illustrating the sequence of steps in the formation of the attenuator of FIGS. 3–5 . The starting material is a bare ceramic substrate typically measuring about 3 inches by 3 inches although other sizes of ceramic substrate may also be used in the practice of the invention. As mentioned above, suitable ceramic materials include aluminum oxide (Alumina), aluminum nitride (ALN), beryllium oxide (BeO), CVD diamond, or epoxy-glass laminates such as FR-4 or G-10. Low temperature co-fired ceramic may also be used as substrates in the practice of the invention. Individual devices that measure approximately 0.125 inches by 0.060 inches each are formed simultaneously on the ceramic substrate using screen printing technology in which layers of material are first printed on the substrate and then fired at an appropriate temperature in the range of 600 deg, C. to 900 deg. C. To maximize the number of devices formed on a substrate, the devices are aligned in a rectangular array. For convenience of illustration, FIGS. 8A–8N depict the steps performed in making one such device but it will be understood that the same steps are being performed simultaneously on all the devices being made on the ceramic substrate. At the end of the formation process, the ceramic substrate is scribed and the individual devices are separated using well-known techniques.
The underside of the ceramic substrate is first metallized as shown in FIG. 8B to provide ground plane 501 and first and second dielectric layers optionally are then deposited on the top-side of the substrate as shown in FIGS. 8C and 8D . Next, individual heater structures 400 are formed in FIGS. 8E and 8F by first printing gold contact layers 404 , 406 and then printing heating elements 408 . Illustratively, the resistance of each heating element 408 is 150 ohms. The heating structures 408 are then covered by one or more dielectric layers in FIGS. 8G and 8H .
Gold contact areas 311 , 314 , 318 , 319 and 322 are then printed in FIG. 81 and the temperature sensor 316 is printed in FIG. 8J . Illustratively, the temperature sensor is a thick-film 10K ohm thermistor with a negative temperature coefficient of resistance. Next, the attenuator is formed by screen printing the series thermistors 310 as shown in FIG. 8K and then the shunt thermistor 312 as shown in FIG. 8 L. Illustratively, the thermistors are thick-film thermistors and the series thermistors have a positive TCR and the shunt thermistor has a negative TCR. Alternatively, thin-film thermistors could be used for temperature sensor 316 and the series and shunt resistors.
As shown in FIG. 8M , the thermistors can then be laser-trimmed to adjust their resistance; and in FIG. 8N a protective layer is printed on the top surface. Product markings such as the manufacturer's name and part numbers can then printed on each device and the devices are then ready for testing. Following testing, the ceramic substrate is scribed and the individual devices are separated. Advantageously, the ground plane facilitates the soldering of the attenuator onto a larger substrate and electrical connections to the attenuator are made by wire bonding lead wires to the various contact areas. As will be apparent to those skilled in the art, the order of some of these steps can be varied. In addition, while firing would typically be carried out after each printing step, it may be advantageous to combine some of the firing steps.
The attenuators of the present invention are suitable for numerous applications including amplifier gain calibration, the balance of multiple channels and automatic gain control. They can be used to maintain oscillator output constant over frequency or reduce the output of a transmitter if the standing wave ratio is too high. They have an extremely wide frequency operating range being operable from DC to 20 GHz or higher. Since their components are completely passive, they are free of any distortion.
Typical specifications for the attenuators of the present invention are:
impedance
50
ohms nominal
frequency range
DC to 20
GHz or higher
insertion loss
1.5
dB Max
attenuation range
3
dB above insertion loss
attenuation flatness
+/−0.25
to dB to 10 GHz
VSWR
1.3
Max
response time
100
mS Max
RF power
250
mW Max
operating temperature
−55° C. to 125° C.
The foregoing description, for purposes of explanation, used specific examples to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the invention is not limited to these examples. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. Thus, the foregoing disclosure is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings.
While the invention was described for the example of a Tee attenuator, the invention may also be practiced using other attenuators such as a Pi attenuator or a bridged Tee attenuator in which a thermistor is connected in parallel to the pair of series resistors of the Tee attenuator. Of particular note, it should be observed that a wide range of attenuations can be achieved by appropriate selection of the TCRs of the various thermistors and whether the TCRs are positive or negative. In some cases, it is not necessary for every resistive element on the attenuator to have a resistance that varies with temperature and the invention may be practiced where one of the resistive elements has a zero TCR. As will be appreciated, the impedance that is observed over the operating frequency range and/or operating temperature range of the attenuator will not be precisely constant and the variation in impedance will depend on the amount of attenuation provided by the attenuator. At low attenuation, deviation from the desired impedance may be within +/− a few percent of the desired impedance over the operating range. At higher attenuations, deviation from the desired impedance can be expected to be higher, for example, +/−10%, +/−20%, and even +/−50% or more. In practice, considerable variation in impedance may be tolerated depending on the specific application in which the attenuator is used and the temperature and frequency range of use. As a rule of thumb, the variation in impedance of the attenuator should be such that the Voltage Standing Wave Ratio (VSWR) of the RF power is no more than 2.0:1 over the operating range of the attenuator.
It is intended that the scope of the invention be defined by the following claims and their equivalents. | A preferred embodiment of the present invention comprises at least first and second thermistors, arranged into a classical Tee, Pi, or Bridged Tee attenuator design, a heating element, a temperature sensor, and a control circuit. The thermistors have different temperature coefficients of resistance and are in close proximity to the heating element and the temperature sensor. The control circuit receives a voltage signal from the temperature sensor, compares that signal with a voltage signal specifying a desired temperature, and applies electrical energy to the heating element until receiving a signal from the temperature sensor that the temperature of the thermistors matches the desired temperature. As a result, the attenuation of the attenuator can be changed at a controlled rate by varying the temperature of the thermistors, while the impedance of the attenuator remains within acceptable levels. | 7 |
This application is a continuation, of application Ser. No. 06/572,711 filed Jan. 20, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates in general to glazed nuclear fuel pellets and glazing compositions therefor, and more particularly, to the use of cadmium-113 isotope in the form of cadmium oxide (CdO) as a burnable absorber, also referred to as a burnable poison, in a glazing composition including other glass forming oxides for glazing nuclear fuel pellets for controlling the nuclear reactivity of a reactor core and ultimately extending the operating life cycle of the nuclear reactor.
The process of nuclear fission involves the disintegration of fissionable nuclear fuel material into two or more fission products of lower mass number. Among other things, the process also includes a net increase in the number of available free neutrons which are the basis for a self-sustaining reaction. When a reactor has operated over a period of time, the fuel assembly with fissionable materials must ultimately be replaced due to depletion. Inasmuch as the process of replacement is time consuming, taking as much as six weeks, and costly in terms of lost power generation, it is desirable to extend the life of a given fuel assembly as long as practically feasible. For that reason, deliberate additions to the reactor fuel of parasitic neutron-capturing elements in calculated small amounts may lead to highly beneficial effects on a thermal reactor. Such neutron-capturing elements are usually designated as burnable absorbers if they have a high probability or cross section for absorbing neutrons while producing no new or additional neutrons or changing into new absorbers as a result of neutron absorption. During reactor operation, the burnable absorbers are progressively reduced in amount so that there is a compensation made with respect to the concomitant reduction in the fissionable material.
The life of a fuel assembly may be extended by combining an initially larger amount of fissionable material, as well as a calculated amount of burnable absorber. During the early stages of operation of such a fuel assembly, excessive neutrons are absorbed by the burnable absorber which undergoes transformation to elements of low neutron cross section which do not substantially affect the reactivity of the fuel assembly in the latter period of its life when the availability of fissionable material is lower. The burnable absorber compensates for the larger amount of fissionable material during the early life of the fuel assembly, but progressively less absorber captures neutrons during the latter life of the fuel assembly, so that a long life at relatively constant fission level is assured for the fuel assembly. Accordingly, with a fuel assembly containing both fissionable material and burnable absorber in carefully proportioned quantities, an extended fuel assembly life can be achieved with relatively constant neutron production and reactivity. Burnable absorbers which may be used include boron, gadolinium, cadmium, samarium, europium, and the like, which upon the absorption of neutrons result in isotopes of sufficiently low neutron capture cross section so as to be substantially transparent to neutrons.
The incorporation of burnable absorbers in fuel assemblies has thus been recognized in the nuclear field as an effective means of increasing fissionable material capacity and therby extending reactor core life, for example, to eighteen months without the requirement for fissionable material replacement. Burnable absorbers are used either uniformly mixed with the fissionable material, i.e., distributed absorber, deposited as a coating on the exterior of nuclear fuel pellets containing fissionable material as disclosed in U.S. Pat. No. 3,427,222, or are placed discretely as separate elements in the reactor core. Thus, the net reactivity of the reactor core can be maintained relatively constant over the active life of a reactor core.
Where burnable absorbers are deposited as a coating on the exterior of nuclear fuel pellets, boron containing compounds such as boron carbide (B 4 C), boron nitride (BN) and zirconium diboride (ZrB 2 ) are most frequently used. Boron containing burnable absorbers may be applied as a coating of predetermined thickness to nuclear fuel pellets by a variety of techniques, for example, dip coating a nuclear fuel pellet in a composition containing a boron compound and a ceramic binder as disclosed in the above-mentioned United States Patent. However, the use of boron containing compounds as a burnable absorber is known to have a number of undesirable characteristics. For example, boron has a moderate burnout rate which often leaves residual burnable absorber within the coating at the end of any given time, thereby often adversely affecting the calculated control of the nuclear reactivity over the operating life cycle of the nuclear reactor. In addition, the burnout of boron from the coating often results in the retention within the fuel rods of undesirable gases produced by the boron burnout, thereby also adversely affecting the performance of the nuclear fuel rod and burnable absorber.
Accordingly, it can be appreciated that there is an unsolved need for a glazed nuclear fuel pellet and a glazing composition therefor which includes one or more burnable absorbers having a controlled increased rate of burnout without producing undesirable gases such that the nuclear reactivity of a reactor core can be effectively controlled and ultimately extending the operating life cycle of the nuclear reactor.
SUMMARY OF THE INVENTION
It is broadly an object of the present invention to provide a cadmium oxide (CdO) glazed nuclear fuel pellet and glazing composition therefor which overcomes or avoids one or more of the foregoing disadvantages resulting from the use of the above-mentioned prior art burnable absorbers, and which fulfills the specific requirement of such a glazed nuclear fuel pellet and glazing composition therefor for use generally with nuclear reactors having one or more fuel assemblies. Specifically, it is within the contemplation of one aspect of the present invention to provide a cadmium oxide glazed nuclear fuel pellet and glazing composition therefor which controls the reactivity and extends the operating life cycle of a fuel assembly while increasing the rate of burnout of the burnable absorber and reducing the amount of undesirable gases produced therefrom.
A further object of the present invention is to provide a glazed nuclear fuel pellet and glazing composition therefor having cadmium-113 isotope in the form of cadmium oxide as a burnable absorber which increases the rate of burnout of the burnable absorber and therefore results in less burnable absorber being present at the end of any given time.
A still further object of the present invention is to provide a glazing composition including cadmium oxide as a burnable absorber for glazing nuclear fuel pellets wherein the glazed coating is both hard and durable for use in a nuclear reactor.
A yet still further object of the present invention is the use of cadmium-113 isotope in the form of cadmium oxide in the substitution, wholly or in part, for boron-10 isotope containing compounds of the prior art burnable absorbers.
In accordance with one embodiment of the present invention, there is provided a glaze forming composition for glazing nuclear fuel pellets with a burnable absorber, the composition comprising at least about 0.5 percent by weight cadmium oxide (CdO) as a first burnable absorber and at least one glaze forming oxide.
In accordance with the above embodiment of the present invention, the glaze forming oxide is selected from the group consisting of silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), boric oxide (B 2 O 3 ), sodium monoxide (Na 2 O), potassium oxide (K 2 O), lead monoxide (PbO), and mixtures thereof.
Still further in accordance with the above embodiment, there is further included a second burnable absorber, the first and second burnable absorbers having different neutron capture cross sections, and wherein the second burnable absorber comprises boron in at least the form of boron-10 isotope, for example, sodium borate (Na 2 B 4 O 7 .10H 2 O).
In accordance with another embodiment of the present invention, there is provided a glazed nuclear fuel pellet comprising fissionable material formed into a body and a glaze provided over at least a portion of the surface of the body, the glaze comprising a mixture of at least 0.5 percent by weight cadmium oxide (CdO) as a first burnable absorber and at least one glaze forming oxide.
In accordance with the last-mentioned embodiment, the glaze forming oxide comprises a borosilicate glass.
BRIEF DESCRIPTION OF THE DRAWING
The above description, as well as further objects, features, and advantages of the present invention, will be more fully understood by reference to the following detailed description of a presently preferred, but nonetheless illustrative, cadmium oxide glazed nuclear fuel pellet and glazing composition therefor in accordance with the present invention, when taken in conjunction with the sole accompanying drawing, wherein such drawing discloses a nuclear fuel pellet of fissionable material having a glazed coating containing at least 0.5 percent by weight cadmium oxide as a burnable absorber.
DETAILED DESCRIPTION
Cadmium oxide has been found by the inventor to be similar in chemical behavior to the lead and zinc oxides, but generally forms higher melting compounds than lead oxide. For example, cadmium silicate melts at about 1240° C., whereas lead silicate melts at about 750° C. A cadmium oxide/boron oxide eutectic melts at about 900° C., whereas a lead oxide/boron oxide eutectic melts at about 500° C. In accordance with the present invention, glasses suitable for use as a glaze on nuclear fuel elements and containing a burnable absorber can be made using cadmium oxide instead of lead oxide, except that such glazes must be fired at higher temperatures than the lead-based glazes. In particular, it has been further found that there are a group of glasses known as borosilicate glasses which include boron trioxide as a suitable glass forming component. Since cadmium oxide, like lead oxide, forms a series of glasses with silicon dioxide, the present invention broadly contemplates the substitution of cadmium oxide, wholly or in part, for the boron trioxide in these borosilicate glasses.
Referring to the sole FIGURE, there is disclosed a nuclear fuel pellet 100 of fissionable material, that is, a material fissionable by neutrons of thermal energy such as U-235, U-233 and Pu-239. Coating the exterior of the nuclear fuel pellet 100 is a glaze 102 which includes a burnable absorber, which in accordance with the present invention, comprises an oxide of cadmium-113 isotope which has a neutron capture cross section of about 20,000 barns per atom. The cadmium-113 isotope is about five times more effective as a burnable absorber than the boron-10 isotope which has a neutron capture cross section of only about 3850 barns per atom. The glaze 102 containing cadmium-113 isotope is useful as a burnable absorber in effectively controlling the reactivity of a reactor core and ultimately extending the operating life cycle of the nuclear reactor. The camdium-113 isotope, as a constituent of the glaze 102 coating the nuclear fuel pellet 100, functions as a burnable absorber which burns out at a rate which reduces the negative reactivity introduced into the reactor by the cadmium-113 isotope at a rate approximately equal to the decline in excess reactivity due to fissionable material depletion. The glaze 102, in addition to containing the oxide of cadmium-113 isotope as a burnable absorber, contains any of the common constitutes of glass such as silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), boric oxide (B 2 O 3 ), sodium monoxide (Na 2 O), potassium oxide (K 2 O), lead monoxide (PbO), and mixtures thereof. However, in accordance with the present invention, it has been found that for the glaze 102 to be useful as a burnable absorber, the oxide of the cadmium-113 isotope should be present in greater than about 0.5 percent by weight. For example, the glaze 102 may contain cadmium oxide in the range of about 50 to 95 percent by weight; preferably in the range of about 70 to 95 percent by weight cadmium oxide; the preferred range being about 82 to 90 percent by weight cadmium oxide; and the balance being, for example, silicon dioxide.
The use of boron-10 isotope as a burnable absorber in a coating on a nuclear fuel pellet contemplates a concentration of the order of 3.2 milligrams of natural boron per centimeter of pellet length. The corresponding quantity of cadmium-113 isotope is 11.0 milligrams of natural cadmium per centimeter of pellet length. When cadmium-113 isotope is substituted for the boron-10 isotope, such substitution would, for example, be approximately in the ratio of 11 parts by weight of cadmium to 3.2 parts by weight of boron. This substitution of the oxide of cadmium-113 isotope for the boron-10 isotope, increases the rate of burnout of the burnable absorber, reduces the amount of undesirable gases produced by the burnout of the boron, and produces a harder and more refractory glaze coating. In this regard, the cadmium-113 isotope produces no gaseous products as a result of neutron capture. Thus, the use of the oxide of cadmium-113 isotope as a burnable absorber burns out more rapidly than the boron-10 isotope and leaves less residual burnable absorber at any given time than that of the boron-10 isotope.
Referring again to the sole FIGURE, a typical nuclear reactor pellet 100 of fissionable material, such as enriched uranium dioxide or mixed oxides, might be of the order of 0.5 inches (1.3 centimeters) in length. The nuclear fuel pellet 100 is expected to have a cadmium silicate glaze coating containing about 16 milligrams of the oxide of cadmium-113 isotope, i.e., about 87 percent cadmium by weight. However, greater or lesser amounts of cadmium oxide may be used in coating such nuclear fuel pellets as the present invention broadly relates to the use of cadmium oxide as a burnable absorber in a glaze for such nuclear fuel pellets, wherein cadmium-113 isotope is substituted, wholly or in part, for boron-10 isotope.
Further, although there has thus far been described the use of the oxide of cadmium-113 isotope as a burnable absorber in a glaze for nuclear fuel pellets, it is also contemplated that a combination of two burnable absorbers, each having different neutron capture cross sections, may be incorporated into the glaze for controlling the reactivity of the reactor core and ultimately extending the operating life cycle of the nuclear reactor. The incorporation of more than one burnable absorber having different neutron capture cross sections, provides an extra degree of freedom for the nuclear engineer in the design of a reactor core. The two burnable absorbers burn out at different rates so that the reactivity of the reactor core can be controlled with more finesse. The use of such a sophisticated control can result in savings of fissionable material and produce more energy per unit of fissionable material loaded into a reactor core. In accordance with the present invention, a cadmium borosilicate glaze may contain from about 50 to 75 percent by weight cadmium oxide, two (2) to three (3) percent by weight boric oxide, three (3) to six (6) percent by weight potassium oxide and the balance silicon dioxide. The boron-10 isotope can also be present as sodium borate (Na 2 B 4 O 7 .10H 2 O).
The glaze 102 is applied to the nuclear fuel pellet 100 by a dip coating process. Generally, the constitutes of the glaze 102 are ground to a fine powder and made into a thin slurry with water. The pellets 100 to be glazed are dipped into the slurry which can be thickened or thinned to produce the ultimate coating of the proper thickness. The wet glaze containing cadmium oxide is dried to about 70° to 90° C. and subsequently fired to melt the glaze to hard refractory coating upon cooling. However, it should be noted that the nuclear fuel pellet 100 may be dipped into the slurry one or more times as required to produce the ultimate coating thickness, each dip being followed by a drying step. Thus, several dips can be applied to provide greater coating thicknesses as required.
The following example is illustrative of the present invention in applying a glaze 102 containing the oxide of cadmium-113 isotope as a burnable absorber of predetermined thickness to a nuclear fuel pellet 100 containing fissionable material.
EXAMPLE I
A cadmium silicate glaze composition for glazing nuclear fuel pellets in accordance with the present invention was prepared by grinding cadmium oxide powder and pure quartz powder in a porcelain ball mill with porcelain balls for 48 hours. The resulting mixed powders containing 89 percent by weight cadmium oxide, the balance silicon dioxide, was made into a slurry using water. Cylinders of uranium dioxide were dipped into the slurry and dried at about 70° to 90° C. and subsequently weighed. The dipping process was repeated until the cylinders had picked up the desired weight of dry slurry, that is, about 18 mg per 1.3 centimeters of cylinder length. The coated cylinders were fired at 1350° C. in an inert atmosphere furnace for three (3) hours to produce ceramic cylinders with a nearly uniform coating of cadmium silicate glaze of about five (5) microns thick. The glaze cylinders were heated and cooled in the furnace at a rate less than 15° C. per minute to prevent thermal shock to the cylinders. The furnace cycle was about two (2) hours for heat up, three (3) hours at glazing temperature, and twelve (12) hours for cool down.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made in the illustrative embodiments and that other arangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. In particular, although an exemplary application of the present invention would glaze nuclear fuel pellets (each having a generally cylindrical configuration with an approximately one-third inch diameter and an approximately one-half inch length) for placement in fuel rods which make up fuel assemblies, the glazing of nuclear fuel plates, columns or other nuclear fuel shapes is considered to be equivalent to the glazing of nuclear fuel pellets, which has been hereinbefore described. | A cadmium oxide glazed nuclear fuel pellet and glazing composition therefor is disclosed which controls the reactivity and extends the operating life cycle of a nuclear reactor while increasing the rate of burnout of the burnable absorber and reducing the amount of undersirable gases produced therefrom. The glaze forming composition comprises at least about 0.5 percent by weight cadmium oxide as a burnable absorber, i.e., cadmium-113 isotope, and at least one glaze forming oxide. The glaze constituents are formed into a slurry and a nuclear fuel pellet is dipped into the slurry to produce a hard refractory glaze upon firing and cooling. | 2 |
TECHNICAL FIELD
The present invention relates to water heaters, and more particularly to heat pump water heaters.
BACKGROUND OF THE INVENTION
Hot water heaters monitor water temperature to determine when water should be heated to maintain a selected water temperature level. Heaters incorporating heat pumps to heat the water energize and de-energize a heat pump based on a measured temperature. If the temperature falls below a selected threshold, the heat pump may be energized to reheat the water. When demand for hot water drops, the heat pump may be de-energized. Operation of the heat pump should accurately track hot water demand to ensure maximum heating efficiency.
Water in the tank tends to stratify, with hot water at the top of the tank near a hot water outlet pipe and cold water at the bottom of the tank near a cold water inlet pipe. Water heated by the heat pump is deposited at the top of the tank, providing additional water that can be output via the output pipe. Thermometers may be placed in the outlet pipe, the inlet pipe, and/or a water pump that sends water to the heat pump to determine whether to energize the heat pump, but the stratification of the water in the tank makes it difficult for the temperature reading to accurately reflect the water temperature in the tank itself through temperature measurements in the pipes. Although it is possible to circulate the water through the de-energized heat pump and the tank to eliminate the stratification before measuring temperature, this would send cold water to the hot water at the top of the tank, undesirably lowering the overall water temperature and potentially requiring the heat pump to energize even though there originally may have been enough hot water at the top of the tank to meet demand. Because of this, any disturbance in the stratification of water in the tank is considered undesirable.
It is possible to place a temperature sensor at the hot water outlet pipe itself because this temperature would reflect the water that will be output to a user. However, if there is no demand for hot water for an extended period of time, the water in the tank may be cooler than the water in the outlet pipe. While the heat pump may be energized as soon as the water flowing through the outlet pipe reflects the lowered temperature of the water in the tank, the large amount of water in the tank causes a long time delay between the time the temperature drop is detected and the time the water is hot enough to use. Thus, currently known systems are unable to provide a temperature reading that is relevant enough to the temperature of usable hot water in the tank to accurately indicate whether the heat pump should be energized.
There is a desire for a system that can provide relevant, accurate temperature information for determining whether to energize a heat pump, improving energy efficiency.
SUMMARY OF THE INVENTION
The present invention is directed to an energy-efficient heat pump water heating system. In one embodiment, the system determines whether to energize a heat pump by interpreting readings based on one or more strategically placed temperature sensors based on two thresholds. The heat pump is energized if the detected temperature falls below a first threshold and de-energized when the detected temperature rises above a second threshold. In an alternative embodiment, the thresholds may correspond to outputs of two or more sensors; for example, the heat pump may be energized if a reading from a first sensor drops below a first threshold and de-energized if a reading from a second sensor moves above a second threshold. Using multiple thresholds improves the temperature sensing capabilities of the system, thereby improving energy efficiency by matching heat pump operation with hot water demand more closely than previously known systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representative diagram of a heat pump water heater according to one embodiment of the invention;
FIG. 2 is a flow diagram illustrating a heat pump control process according to one embodiment of the invention;
FIG. 3 is a flow diagram illustrating a heat pump control process according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 is a representative diagram of a heat pump water heater 100 according to one embodiment of the invention. In the illustrated embodiment, the heater 100 includes a water tank 102 connected to a heat pump 104 . Water circulates between the tank 102 and the heat pump 104 via pipes, including a tank inlet pipe 106 and a tank outlet pipe 108 . The tank inlet pipe 106 carries hot water heated by the heat pump 104 and deposits in into the top of the tank 102 , while the tank outlet pipe 108 directs cold water from the bottom of the tank 102 to the heat pump 104 to be heated.
In addition to the pipes directing water between the tank 102 and the heat pump 104 , other pipes are included to link the heat pump water heater 100 to external systems. In this example, a cold water tank inlet pipe 110 supplies cold water from an external source (not shown) to the bottom of the tank 102 for eventual heating by the heat pump 104 . A hot water tank outlet pipe 112 at the top of the tank 102 removes hot water from the tank for use.
The heat pump 104 itself includes a water pump 114 and a heat exchanger 116 . The heat pump 104 may employ a transcritical vapor compression cycle, if desired, and may employ any appropriate refrigerant, such as carbon dioxide. Although the water pump 114 is shown in the path of the tank outlet pipe 108 in this embodiment, the water pump 114 may also be located in the tank inlet pipe 106 without departing from the scope of the invention. The water pump 114 pumps water through the heat exchanger 116 , where it absorbs heat. Once the pumped water has absorbed heat through the exchanger, it travels through the tank inlet pipe 106 and is delivered to the tank 102 for storage. A controller 118 controls energization and de-energization of the heat exchanger 116 ; in the illustrated example, the controller 118 controls operation of the water pump 114 and the heat exchanger 116 independently so that water can be circulated by the water pump 114 while the heat exchanger 116 is de-energized, if desired.
One or more temperature sensors are included in the heater 100 to monitor water temperature in the tank 102 and energize/de-energize the heat pump 104 (i.e., energize/de-energize both the water pump 114 and the heat exchanger 116 ) based on whether or not the water temperature needs to be raised and based on hot water demand.
To avoid irrelevant water temperature measurements due to stratification in the tank 102 and cooling of the water in the tank 102 after prolonged disuse of the water, a tank temperature sensor 120 is disposed at roughly the midpoint of the tank 102 or at any other desired location in the tank 102 . Placing a temperature sensor 120 in the tank 102 allows direct measurement of the water temperature in the tank, making the temperature reading relevant in determining whether to operate the heat pump 104 without requiring recirculation of water through the heater 100 . More particularly, the water temperature in the tank 102 will provide a better indication than the water temperature in any of the pipes 106 , 108 , 110 , 112 regarding whether the water in the tank needs to be heated even with the stratification effect of different water temperatures in the tank 102 .
The tank temperature sensor 120 provides a temperature reading to the controller 118 . In one embodiment, the controller 118 evaluates the temperature reading with a predetermined first threshold and energizes the heat pump 104 if the temperature drops below the first threshold, indicating that the water temperature in the tank 102 is not high enough to meet hot water demand. Evaluating water temperature using two separate thresholds provides a more accurate indication of the demand for hot water without requiring recirculation of cold water into the hot water at the top of the tank. As a result, the heat pump 104 will operate only in response to hot water demand and not when stratification is disturbed due to recirculation.
To add further control over heat pump operation, the controller 118 may instruct the heat pump 104 to de-energize when a temperature reading reaches a second threshold. The temperature reading may be taken from the tank temperature sensor 120 or from another temperature sensor in the system. If the tank temperature sensor 120 is evaluated based on both the first and second thresholds, the heat pump 104 may simply be energized if the temperature falls below the first threshold and de-energized when it reaches the second threshold.
In another embodiment, the second threshold may evaluate a temperature reading from a tank inlet temperature sensor 122 placed in the tank inlet pipe 106 , which measures the temperature of hot water being deposited into the top of the tank 102 . This temperature reading is then used to estimate the water temperature in the tank outlet pipe 108 based on the system 100 heating capacity and the water flow rate through the system 100 using, for example, the following relationship:
heating capacity= K *water flow*(inlet pipe temp−outlet pipe temp)
where K is the specific heat of water. Using one sensor and calculating the estimated water temperature elsewhere allows fewer sensors to be used in the system.
Alternatively, a tank outlet temperature sensor 124 , which may be any temperature sensor near the bottom of the tank 102 , may be included to measure the water temperature in the tank outlet pipe 108 directly. Using two sensors, one near the top of the tank 102 and one near the bottom of the tank 102 or along the tank outlet pipe 108 , provides greater control over heat pump operation than a single sensor because the sensor near the top of the tank 102 can be used to decide when to turn the heat pump on and the sensor near the bottom of the tank 102 or in the tank outlet pipe 108 can be used to decide when to turn the heat pump off. Regardless of the specific location of the sensors, measuring water temperature in a given pipe should be conducted when the water pump 114 is operating and moving water through the system to obtain the most relevant reading.
FIG. 2 illustrates a method of controlling the heat pump in this manner according to one embodiment of the invention. In this embodiment, the tank temperature sensor 120 monitors the tank temperature and sends the temperature reading to the controller 118 (block 200 ). The controller 118 checks whether the tank temperature reading falls below the first threshold (block 201 ). If so, the heat pump is energized (block 202 ) to heat water as it circulates through the heat pump. This will cause the overall water temperature in the tank 102 to rise gradually as the heated water mixes with the cooler water in the tank 102 . The temperature of the heated water flowing through the tank inlet pipe 106 is then monitored (block 204 ). The temperature reading is used to calculate the water temperature in the tank outlet pipe 108 based on the system heating capacity and the water flow rate, as explained above (block 206 ). The accuracy of the temperature calculation will depend on how closely the capacity and flow rate values match the system's actual operating characteristics. If the calculated tank outlet pipe temperature reaches a second threshold (block 208 ), indicating that the hot water temperature has met hot water demand, the heat pump 104 is de-energized (block 210 ) until the tank water temperature drops below the first threshold again.
Alternatively, or in addition, the system may evaluate a temperature reading from the tank outlet pipe 108 directly. FIG. 3 illustrates a method according to another embodiment of the invention. In this embodiment, the water temperature in the tank outlet pipe 108 is monitored directly by the tank outlet temperature sensor 124 , thereby eliminating the need to estimate the tank outlet pipe temperature as in the previous embodiment. In this embodiment, the method simply de-energizes the heat pump 104 if the temperature in the tank outlet pipe 108 reaches the second threshold (block 220 ).
Thus, the invention improves energy efficiency by energizing the heat pump 104 only when needed. By measuring the water temperature in the middle of the tank and by evaluating water temperature using two different thresholds, the invention avoids unnecessary circulation and reheating, improving energy efficiency while still responding accurately to hot water demand.
It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. | An energy-efficient heat pump water heating system determines whether to energize a heat pump by interpreting readings from one or temperature sensors based on two thresholds. The heat pump is energized if the detected temperature falls below a first threshold and de-energized when the detected temperature rises above a second threshold. The thresholds may correspond to outputs of two or more sensors. Using multiple temperature thresholds improves the temperature sensing capabilities of the system, thereby improving energy efficiency by matching heat pump operation with hot water demand more closely than previously known systems. | 5 |
TECHNICAL FIELD
The present disclosure relates to a catheter assembly, and, in particular, to a symmetrical tip acute catheter.
BACKGROUND
Catheters are flexible medical instruments intended for the withdrawal and introduction of fluids to and from body cavities, ducts and vessels. Catheters have particular application in hemodialysis procedures, in which blood is withdrawn from a blood vessel for treatment and subsequently returned to the blood vessel for circulation. Hemodialysis catheters can include multiple lumens, such as dual lumen or triple lumen catheters, which pemit bi-directional fluid flow within the catheter whereby one lumen, the arterial lumen, is dedicated for withdrawal of blood from a vessel and the other lumen, the venous lumen, is dedicated for returning purified blood to the vessel. During some hemodialysis procedures, a multiple lumen catheter is inserted into a body, and blood is withdrawn through the arterial lumen of the catheter. The withdrawn blood is directed to a hemodialysis unit which dialyzes, or purifies, the blood to remove waste and toxins Thereafter, the dialyzed blood is returned to the patient through the venous lumen of the catheter.
Generally, hemodialysis catheters are categorized as either chronic or acute in nature. Chronic catheters typically remain in place for extended periods of time, and may be implanted via surgical dissection. Acute catheters, by comparison, are designed to be placed in a patient under emergent circumstances in which speed of placement is desirable. Acute catheters typically remain in place for only a few days. As such, acute catheters are often more rigid than chronic catheters, given the urgency of placement.
In hemodialysis catheters, recirculation can occur when purified blood exiting the venous lumen of the catheter is withdrawn directly into the arterial lumen such that purified blood is returned to the dialyzer. As such, recirculation increases the time required to complete the hemodialysis procedure.
SUMMARY
The present disclosure is directed to further improvements in hemodialysis catheters and systems used therewith. A catheter assembly includes an elongate catheter member, and a catheter tip. The elongate catheter member includes a septum defining at least a portion of each of a pair of internal lumens. The catheter tip is coupled to a distal end of the elongate catheter member and is symmetric about a plane defined by the septum. The catheter tip includes a distal portion and a proximal portion, an upper surface, a lower surface, and side surfaces between the upper and lower surfaces, the distal portion including a closed distal end. The catheter tip defines first and second lumens and first and second openings in the distal portion of the catheter tip. Each opening is defined by a respective side surface of the catheter tip. Each opening is in fluid communication with a respective one of the first and second lumens of the catheter tip and with a respective one of the first and second lumens of the elongate catheter member. The distance between the upper and lower surfaces of the catheter tip decreases from a distal end of the proximal end portion toward the closed distal end. The first and second openings are diametrically opposed to one another and may be laser-cut or otherwise formed to have contoured edges to reduce the likelihood of thrombus formation.
The first and second passages of the catheter tip are in fluid communication with a respective one of the pair of internal lumens of the elongate catheter member such that fluids may pass between the elongate catheter member, the catheter tip, and the first and second opening so that the catheter member is in fluid communication with an outside environment such as an internal body cavity. The pair of internal lumens may be configured for opposing bi-directional fluid flow, as in the case of hemodialysis procedures. In embodiments, one or more connecting members may be disposed between the elongate catheter member and the catheter tip, and the one or more connecting members may define channels to facilitate communication between the elongate catheter member and the catheter tip. Distal ends of the connecting members may be disposed adjacent the proximal ends of the first and second side openings such that fluids exit the connecting members upon reaching the proximal ends of the first and second side openings.
In embodiments, the distance between the upper and lower surfaces along the proximal portion increases in the distal direction adjacent the distal portion. In another embodiment, the proximal portion of the catheter tip is defined by a curved spheroid region. In still another embodiment, the first and second openings are each an elongate oval.
In a further embodiment of the present disclosure, the elongate catheter member defines a longitudinal axis and the first and second side openings are spaced a distance along the longitudinal axis from the distal end of the catheter tip. In another embodiment of the present disclosure, the first and second internal lumens are semicircular in cross-sectional shape.
In still another embodiment, the elongate catheter member and the catheter tip are coupled by at least one connecting member extending therebetween. The at least one connecting member defines a channel in fluid communication with the elongate catheter member and the catheter tip. The at least one connecting member may include a proximal end and a distal end, and the distal end of the connecting member is adjacent one of the first and second side openings. The first and second side openings each have a contoured perimeter.
In a further embodiment of the present disclosure, a medical catheter includes an elongate tubular member defining a pair of lumens and a longitudinal axis. A pair of diametrically opposed side openings in fluid communication with the respective pair of lumens. Each side opening has a proximal end and a distal end, and each side opening has an elongated substantially z-shaped configuration including a rectangular central portion defining a transverse axis and triangular proximally and distally extending portions. The triangular proximally extending portion defines an apex at the proximal end of the side opening and the triangular distally extending portion defines an apex at the distal end of the side opening. The transverse axis of the rectangular central portion defines an acute angle with the longitudinal axis of the elongate tubular member. The acute angle can be between about fifteen and about seventy-five degrees. In some embodiments, the elongate tubular member includes a septum defining at least a portion of each of the pair of lumens. The septum extends parallel to the longitudinal axis, and the elongate tubular member is symmetrical about a plane defined by the septum. In certain embodiments, the pair of side openings each have contoured edges. In some embodiments, the proximal and distal ends of each of the side openings are rounded.
Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a distal portion of a medical catheter including an elongate catheter member and a tip.
FIG. 2 is a cross-sectional view of the medical catheter of FIG. 1 , taken along section line 2 - 2 of FIG. 1 .
FIG. 3A is a perspective view of the tip of the catheter of FIG. 1 including a pair of side openings.
FIG. 3B is a side view of the catheter tip of FIG. 3A .
FIG. 3C is a top view of the catheter tip of FIG. 3A .
FIG. 4A is a perspective view of a catheter tip which includes a proximal portion having a changing diameter from the proximal portion to the distal portion.
FIG. 4B is a side view of the catheter tip of FIG. 4A .
FIG. 4C is a top view of the catheter tip of FIG. 4A .
FIG. 5A is a perspective view of a catheter tip having a proximal portion with a curved spheroid region.
FIG. 5B is a side view of the catheter tip of FIG. 5A .
FIG. 5C is a top view of the catheter tip of FIG. 5A .
FIG. 6A is a perspective view of an alternate embodiment of a catheter tip having diametrically opposed top and bottom planar surfaces and a proximal portion having top and bottom walls which diverge outwardly as the proximal portion approaches a distal portion of the catheter tip.
FIG. 6B is a side view of the catheter tip of FIG. 6A .
FIG. 6C is a top view of the catheter tip of FIG. 6A .
FIG. 7A is a perspective view of a catheter tip including diametrically opposed planar top and bottom surfaces and having side openings extending through the distal end of the catheter tip.
FIG. 7B is a side view of the catheter tip of FIG. 7A .
FIG. 7C is a top view of the catheter tip of FIG. 7A .
FIG. 8A is a perspective view of a catheter assembly including an elongate catheter member having a pair axially opposed and offset tapered slots.
FIG. 8B is a side view of the catheter assembly of FIG. 8A .
FIG. 8C is a top view of the catheter assembly of FIG. 8A .
FIG. 9A is a perspective view of a catheter assembly including side openings having rounded ends.
FIG. 9B is a side view of the catheter assembly of FIG. 9A .
FIG. 9C is a top view of the catheter assembly of FIG. 9A .
FIG. 10A is a perspective view of a catheter assembly having a catheter body with a pair of diametrically opposed side openings, each shaped as a tapered slot with rounded ends.
FIG. 10B is a side view of the catheter assembly of FIG. 10A .
FIG. 10C is a top view of the catheter assembly of FIG. 10A .
FIG. 11A is a perspective view of a catheter assembly having a catheter body with a pair of diametrically opposed side openings, each having a truncated oval shape with a flat distal wall.
FIG. 11 B is a side view of the catheter assembly of FIG. 11A .
FIG. 11C is a top view of the catheter assembly of FIG. 11A .
FIG. 12A is a perspective view of a catheter assembly having a catheter body with a pair of diametrically opposed side openings each having a shape defined by a circular distal portion intersecting a smaller circular proximal portion.
FIG. 12B is a side view of the catheter assembly of FIG. 12A .
FIG. 12C is a top view of the catheter assembly of FIG. 12A .
FIG. 13A is a perspective view of a catheter assembly having a catheter body with a pair of diametrically opposed side openings each having an L-shape including rectangular slots intersecting in transverse relation.
FIG. 13B is a side view of the catheter assembly of FIG. 13A .
FIG. 13C is a top view of the catheter assembly of FIG. 13A .
FIG. 14A is a perspective view of a catheter assembly having a catheter body with a pair of diametrically opposed side openings having a shape defined by a circular distal portion intersecting a circular proximal portion.
FIG. 14B is a side view of the catheter assembly of FIG. 14A .
FIG. 14C is a top view of the catheter assembly of FIG. 14A .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiments of the presently disclosed catheters are discussed in terms of medical catheters for the administration of fluids and, more particularly, in terms of hemodialysis catheters. However, it is envisioned that the present disclosure may be employed with a range of catheter applications including surgical, diagnostic and related treatments of diseases and body ailments, of a subject. It is further envisioned that the principles relating to the presently disclosed catheters include, for example, hemodialysis, cardiac, abdominal, urinary, intestinal, in chronic and/or acute applications.
In the discussion that follows, the term “proximal” will refer to the portion of a structure closer to an operator, while the term “distal” or will refer to the portion further from the operator. As used herein, the term “subject” refers to a human patient or other animal. The term. “operator” refers to a doctor, nurse or other care provider and may include support personnel.
Referring now to FIGS. 1-2 , a catheter 1 . 0 includes a catheter body 20 and a catheter tip 40 . The catheter body 20 defines a longitudinal axis “A” and may have a substantially circular cross-section. The catheter body 20 defines a pair of lumens 22 , 23 extending the length of catheter 10 . Alternately, the catheter 20 may define a third lumen for receiving a guidewire or the like. The lumens 22 , 23 may include oblong, kidney-shaped, and/or D-shaped cross-sectional configurations. A septum 24 defined by the catheter body 20 is disposed between the adjacent lumens 22 , 23 and can define at least a portion of each lumen 22 , 23 . In some embodiments, the catheter tip 40 has a substantially frusto-conical profile. The frusto-conical shape may aid in the insertion of the catheter 10 , for example, in time-sensitive circumstances in which acute catheters are utilized.
The components of the catheter 10 may be fabricated from materials suitable for medical applications, such as, for example, polymers, silicone and/or polyurethane. The catheter body 20 is flexible and may be formed by injection molding or extrusion. The catheter body 20 may have a preformed bend in its normal condition to facilitate conforming to an internal body cavity or vessel in which the catheter body 20 is to be positioned. Alternatively, catheter body 20 may be substantially straight.
The catheter tip 40 may be fabricated from material suitable for medical application, including, for example, polymers, silicone, and/or polyurethane. In addition, the catheter tip 40 fabricated from the same material or a different material than catheter body 20 . In some embodiments, catheter tip 40 is formed separately from catheter body 20 and is secured to a distal end portion of the catheter body 20 . In certain embodiments, the catheter tip 40 is integrally or monolithically formed with the catheter body 20 .
The catheter tip 40 includes a partition 44 . The catheter tip 40 and the partition 44 define the lumens 42 . An outer surface 47 of catheter tip 40 is tapered distally and approaches a closed, distal end 46 to aid insertion of the catheter 10 . While the distal end 46 is shown as having a rounded, blunt profile, other shapes and profiles of the distal end 46 are possible. When the catheter body 20 and the catheter tip 40 are assembled, the lumens 42 of tip 40 are in fluid communication with and are aligned with the lumens 22 , 23 of the catheter body 20 . Similarly, the septum 24 and the partition 44 are aligned such that lumens 22 , 23 and the respective lumens 42 define substantially parallel and separate pathways parallel to the longitudinal axis A along the catheter body 20 . At least a distal portion of the septum 24 and a proximal portion of the partition 44 have substantially similar dimensions to provide a smooth transition between the catheter body 20 and the catheter tip 40 .
The catheter tip 40 may include a pair of proximally extending connecting members 48 that are insertable into lumens 22 , 23 . The connecting members 48 are spaced to receive septum 24 and define channels 50 . The channels 50 are in fluid communication with the lumens 22 , 23 of the catheter body 20 when the catheter body 20 and the catheter tip 40 are assembled. The connecting members 48 may engage the lumens 22 , 23 with an interference or frictional fit, forming a substantially fluid tight seal with lumens 22 , 23 . Alternatively or additionally, the connecting members 48 may be secured within with lumens 22 , 23 using chemical adhesives or mechanical coupling, such as by welding.
Referring now to FIGS. 3A-3C , a pair of side openings 52 is defined in the outer surface 47 of the catheter tip 40 . The side openings 52 are substantially elongated, oval shaped slots that extend along catheter tip 40 and are symmetrical about the longitudinal axis A. The side openings 52 allow fluid streams F, F′ to travel between an environment, such as an internal body cavity, and the internal lumens 42 . The side openings 52 may have contoured edges formed, for example, by laser cutting, molding with catheter tip 40 , and/or otherwise smoothed to minimize flow disruption and thrombus formation.
In a hemodialysis application, a proximal end portion of catheter body 20 ( FIG. 1 ) is connected to a dialyzer (not shown) such that blood is withdrawn from a body vessel through one lumen 22 ( FIG. 2 ), the arterial lumen, of the catheter body 20 via the respective side opening 52 of the catheter tip 40 and delivered to a dialyzer for purification. The purified blood is then returned to the body vessel through the second lumen 23 , the venous lumen, of the catheter body 20 via the other side opening 52 of the catheter tip 40 . Because of the symmetrical configuration of the catheter body 20 , and the catheter tip 40 and the lumens 42 , either lumen 22 , 23 may serve as the arterial lumen or the venous lumen. Because of the configuration of the catheter tip 40 , the blood flow stream F into the side opening 52 communicating with the arterial lumen 22 and the blood flow stream F′ exiting the side opening 52 communicating with the venous lumen 23 are separated such that the degree of fluid recirculation is minimized.
The symmetrical nature of the catheter tip 40 , the diametrically opposed positioning of side openings 52 along the tip 40 , and the elongated shape of side openings 52 enables the spacing between the fluid stream F′ exiting venous lumen 23 and the fluid stream F entering arterial lumen 22 to be maximized, which minimizes the degree of recirculation of purified blood between the venous lumen 23 and the arterial lumen 22 of the catheter 10 ( FIG. 1 ). Specifically, blood enters proximally through the side openings 52 and exits distally through the side openings 52 . The outer surface 47 and the distal end 46 of the catheter tip 40 provide spacing that substantially minimizes the fluid stream F′ exiting the venous lumen 23 from migrating toward the fluid stream F entering the arterial lumen 22 , which can also minimize the degree of fluid recirculation.
Referring now to FIGS. 4A-4C , a catheter tip 140 includes a proximal portion 141 and a distal portion 143 . The distal portion 143 of the catheter tip 140 gradually tapers towards a closed distal end 146 , which may have a blunt or atraumatic shape. The proximal portion 141 increases in diameter in a direction toward the distal portion 143 . The increase in diameter along proximal portion 141 provides a radially expanding surface proximal to side openings 152 . This radially expanding surface can direct fluid stream F′ away from the side openings 152 . The side openings 152 can be similar in configuration to side openings 52 and define an elongated oval configuration formed along the sides of the outer surface 147 of catheter tip 140 . Because of the configuration of the catheter tip 140 , the blood flow stream F into the side opening 152 communicating with an arterial lumen and the blood flow stream F′ exiting the side opening 152 communicating with a venous lumen are separated such that the degree of fluid recirculation is minimized.
Referring now to FIGS. 5A-5C , a catheter tip 240 includes a proximal portion 241 and a distal portion 243 . The distal portion 243 has a substantially tapered profile that gradually tapers towards a closed distal end 246 . The catheter tip 240 defines a pair of side openings 252 disposed along opposed sides of the outer surface 247 of the catheter tip 240 . The proximal portion 241 of the catheter tip 240 is a curved spheroid region adjacent the distal portion 243 . The curved spheroid region of the proximal portion 241 provides a radially expanding surface proximal to the side openings 252 that directs fluid stream F′ away from side openings 252 to minimize recirculation of fluid stream F′ in the manner discussed above with respect to catheter tip 140 .
Referring now to FIGS. 6A-6C , a catheter tip 340 includes diametrically opposed planar surfaces 354 , a proximal portion 341 and a distal portion 343 . Lateral surfaces 360 of proximal portion 341 diverge outwardly in a direction toward distal portion 343 . Each planar surface 354 extends the length of the catheter tip 340 and converges inwardly approaching a blunt distal end 346 . Side surfaces 362 of the distal portion 343 taper inwardly in a direction approaching the distal end 346 . Side openings 352 are similar to openings 52 , 152 and 252 discussed above. Each side opening 352 is positioned along a respective side surface 362 . The planar surfaces 354 direct fluid stream F′ away from side openings 352 by providing a path of least resistance for fluid stream F′ to flow toward distal end 346 . The lateral surfaces 360 of the proximal portion 341 also direct fluid outwardly of side openings 352 .
Referring now to FIGS. 7A-7C , a catheter tip 440 defines a pair of distally positioned, diametrically opposed side openings 452 along the outer surface of a catheter tip 440 . The side openings 452 extend through a portion of a distal end 446 of the catheter tip 440 . The side openings 452 are in fluid communication with internal lumens 442 of catheter tip 440 . The catheter tip 440 functions in a manner similar to that described above with respect to catheter tip 340 ( FIGS. 6A-6C ).
Referring now to FIGS. 8A-8C , a catheter 510 includes an elongated body 520 and a catheter tip 540 supported at the distal end of the elongated body 520 . The elongated body 520 defines first and second lumens (not shown) which extend from a proximal end of the catheter 510 toward the distal end of the catheter 510 . In some embodiments, the catheter tip 540 is substantially conical and tapers inwardly in the distal direction to define a blunt or atraumatic end.
The catheter body 520 defines first and second side openings 526 diametrically opposed to one another along the length of body 520 . Each side opening 526 is in fluid communication with a respective one of the first and second lumens. Each side opening 526 has an elongated Z-shaped configuration including a rectangular or rhombus-shaped central portion 527 a and triangular proximal and distal portions 527 b and 527 c . The apex of the triangular portion 527 b is at the proximal end of the triangular portion 527 b and the apex of the triangular portion 527 c is at the distal end of the triangular portion 527 c . In some embodiments, the rectangular portion 527 a defines a transverse axis T ( FIG. 8B ) which defines an acute angle θ with a longitudinal axis B defined by the catheter body 520 . For example, the angle θ can be between about fifteen degrees and about seventy-five degrees. In certain embodiments, sidewalls 529 defining a portion of rectangular portion 527 a and triangular portions 527 b and 527 c are substantially parallel to a longitudinal axis B defined by catheter body 520 .
As discussed above, the side openings 526 are symmetrically positioned on opposite sides of the catheter body 520 and each of the side openings 526 communicates with a respective lumen of the catheter 510 . The side openings 526 facilitate separation of the fluid flow stream F into the arterial lumen of the catheter 510 and the fluid flow stream F′ exiting the venous lumen of the catheter 510 . More specifically, because of the configuration of the side openings 526 , blood flow has a tendency to flow into a proximal end of the side opening communicating with the arterial lumen of the catheter body 520 and exit the distal end of the side opening 526 communicating with the venous lumen of the catheter body 520 . Because of this, the fluid streams F and F′ to and from the catheter 510 are spaced to minimize the degree of recirculation within the catheter body 520 .
Referring to FIGS. 9A-9C , a catheter 610 includes a body 620 defining side openings 626 that have rounded proximal and distal ends 627 . The ingress and egress points for fluid flow streams F, F′ through arterial and venous lumens (not shown), respectively, are axially spaced apart as described above. Thus, fluid stream F entering the arterial lumen and fluid stream F′ exiting the venous lumen are circumferentially and axially spaced apart, to minimize the degree of recirculation. As compared to sharp edges, the rounded edges 627 of side openings 626 reduce shear stresses on the blood flow to reduce the likelihood of thrombus formation.
Referring to FIGS. 10A-10C , a catheter 710 defines a pair of diametrically opposed side openings 726 , each side opening having a proximal end 727 and a distal end 728 . The side openings 726 have a substantially teardrop-shaped profile with rounded ends. The taper of the teardrop shape of each side opening 726 tapers proximally from the proximal end 727 to the distal end 728 , with the proximal end 727 having a smaller radius of curvature than the distal end 728 . Fluid stream F enters an arterial lumen at the proximal end 727 . Fluid stream of F′ exits a venous lumen at the distal end 728 . Accordingly, proximal and distal flow of fluid streams F, F′ through respective lumens are both axially and circumferentially spaced to minimize recirculation.
Referring to FIGS. 11A-11C , a catheter 810 defines a pair of diametrically opposed side openings 826 . Each side opening 826 has a proximal end 827 and a distal end 828 and an elongated, truncated oval shape. The distal end 828 of each side opening 826 has a generally flat or planar shape. Each side opening 826 tapers proximally and narrows toward the respective proximal end 827 , which has a curved shape. Fluid stream F enters an arterial lumen at the proximal end 827 and fluid stream F′ exits a venous lumen at the distal end 828 . Accordingly, proximal and distal flow of fluid streams F, F′ through respective lumens are both axially and circumferentially spaced from one another to minimize recirculation.
Referring to FIGS. 12A-12C , a catheter 910 defines a pair of diametrically opposed side openings 926 . Each side opening 926 has a proximal portion 927 , a distal portion 928 , and a substantially pear-shaped profile. The distal portions 928 of each side opening 926 is arcuate and has a first diameter “A 1 ”, and the proximal portion 927 of each side opening 926 is arcuate and has a second diameter “A 2 ” that is smaller than diameter A 1 . The respective proximal portions 927 and distal portions 928 intersect along a transverse axis T′ of catheter 910 . Fluid stream F enters an arterial lumen at the proximal portion 927 , and fluid stream F′ exits a venous lumen at the distal portion 928 . Accordingly, proximal and distal flow of fluid streams F, F′ through respective lumens are both axially and circumferentially spaced relative to one another to minimize recirculation.
Referring to FIGS. 13A-13C , a catheter 1010 defines a pair of diametrically opposed side openings 1026 . Each side opening 1026 has a proximal portion 1027 and a distal portion 1028 and has a substantially L-shaped profile. The distal portion 1028 of each side opening 1026 extends across a portion of the surface of the catheter 1010 in transverse relation to a longitudinal axis A′ of catheter 1010 . The proximal portion 1027 of each side opening 1026 extends along a portion of the surface of the catheter 1010 parallel to the longitudinal axis A′ and intersects a respective distal portion 1028 . Fluid stream F enters an arterial lumen at the proximal portion 1027 and exits a venous lumen at the distal portion 1028 . Accordingly, proximal and distal flow of fluid streams F, F′ through respective lumens are both axially and circumferentially spaced from one another.
Referring to FIGS. 14A-14C , a catheter 1110 defines a pair of diametrically opposed side openings 1126 . Each side opening 1126 has a proximal portion 1127 , a distal portion 1128 , and a substantially figure eight-shaped profile. The proximal portion 1127 and distal portion 1128 of each respective side opening 1126 each have a shape defined by an arcuate distal portion intersecting an arcuate proximal portion, and are symmetric about a transverse axis B″ of the catheter 1110 . Fluid stream F enters an arterial lumen at the proximal portion 1127 , and fluid stream F′ exits a venous lumen at the distal portion 1128 . Accordingly, proximal and distal flow of fluid streams F, F′ through respective lumens are both axially and circumferentially spaced from one another to minimize recirculation.
Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure. | A medical catheter assembly includes a catheter tip coupled to a distal end of an elongate catheter member and is symmetric about a plane defined by a septum of the elongate catheter member. The catheter tip defines first and second lumens, and the catheter tip defines first and second openings in the distal portion of the catheter tip. Each opening of the catheter tip is defined by a respective side surface of the catheter tip. Each opening is in fluid communication with a respective one of the first and second lumens of the catheter tip and with a respective one of a pair of lumens defined by the elongate catheter member. The distance between upper and lower surfaces of the catheter tip decreases from a distal end of the proximal portion toward a closed distal end of the catheter tip. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/050,417, entitled “HUMAN FRP AND FRAGMENTS THEREOF INCLUDING METHODS FOR USING THEM,” filed on May 29, 1997, by Rubin et al., and U.S. Provisional Application No. 60/050,495 entitled “HUMAN FRP AND FRAGMENTS THEREOF INCLUDING METHODS FOR USING THEM,” filed on Jun. 23, 1997, by Rubin et al., which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is in the field of molecular biology and in particular relates to the identification of a novel human Frizzled Related Protein (FRP) involved in cell growth and differentiation.
[0004] 2. Description of Related Art
[0005] Extracellular signaling molecules have essential roles as inducers of cellular proliferation, migration, differentiation, and tissue morphogenesis during normal development. These molecules also participate in many of the aberrant growth regulatory pathways associated with neoplasia. In addition, these molecules function as regulators of apoptosis, the programmed cell death that plays a significant role in normal development and functioning of multicellular organisms, and when disregulated, is involved in the pathogenesis of numerous diseases. See e.g. Thompson, C. B., Science 267, 1456-1462 (1995).
[0006] Apoptosis is a result of an active cell response to physiological or damaging agents and numerous gene products are involved in signal transduction, triggering and executive steps of the apoptotic pathways. Other proteins do not take part in the apoptotic cascade by themselves but modify cell sensitivity to proapoptotic stimuli. While many genes and gene families that participate in different stages of apoptosis have recently been identified and cloned, because the apoptotic pathways have not been clearly delineated, many novel genes which are involved in these processes await discovery.
[0007] The identification and characterization of molecules involved in growth and differentiation is an important step in both the identification of mechanisms of cellular development and oncogenesis and the subsequent conception of novel therapies based on this knowledge. One group of molecules known to play a significant role in regulating cellular development is the Wnt family of glycoproteins. In vertebrates, this family consists of more than a dozen structurally related molecules, containing 350-380 amino acid residues of which >100 are conserved, including 23-24 cysteine residues. See e.g. Parr, B. A. & McMahon, A. P. (1994) Curr Opin Genet Dev 4, 523-8.
[0008] Wnt-1, the first Wnt-encoding gene to be isolated, was identified as an oncogene expressed as a result of insertional activation by the mouse mammary tumor virus (Nusse, R., et al., Nature 307, 131-6 1984). Subsequently, transgenic expression of Wnt-1 confirmed that constitutive expression of this gene caused mammary hyperplasia and adenocarcinoma (Tsukamoto et. al., Cell 55, 619-25 (1988)). Targeted disruption of the Wnt-1 gene revealed an essential role in development, as mouse embryos had severe defects in their midbrain and cerebellum. Thomas et. al., Cell 67, 969-76 (1991). In addition, Wingless (Wg), the Drosophila homolog of Wnt-1, was independently identified as a segment polarity gene (Rijsewijk et al., Cell 50, 649-57 (1987)). Gene targeting of other Wnt genes demonstrated additional important roles for these molecules in kidney tubulogenesis and limb bud development. See e.g. Parr et al., Nature 374, 350-3 (1995); Stark K et al. Nature 372: 679-683, 1994.
[0009] Several aspects of Wnt signaling have been illuminated by studies in flies, worms, frogs and mice (Perrimon, N. (1996) Cell 86, 513-6; Miller, J. R. & Moon, R. T. (1996) Genes Dev 10, 2527-39), but until recently little was known about key events which occur at the external cell surface. Identification of Wnt receptors was hampered by the relative insolubility of the Wnt proteins, which tend to remain tightly bound to cells or extracellular matrix. However, several observations now indicate that members of the Frizzled (FZ) family of molecules including Frzb can function as receptors for Wnt proteins or as components of a Wnt receptor complex. See e.g. He et. al., Science 275, 1652-1654 (1997).
[0010] The prototype for this family of receptor molecules, Drosophila frizzled (Dfz), was first identified as a tissue polarity gene that governs orientation of epidermal bristles. Vinson et al., Nature 329, 549-51 (1987). Cells programmed to express a second Drosophila Fz gene, Fz2, bind Wg and transduce a Wg signal to downstream components of the signaling pathway. Bhanot et al., Nature 382, 225-30 (1996). Each member of the Fz receptor gene family encodes an integral membrane protein with a large extracellular portion, seven putative transmembrane domains, and a cytoplasmic tail. See e.g. Wang et al., J Biol Chem 271. 4468-76 (1997). Near the NH2-terminus of the extracellular portion is a cysteine-rich domain (CRD) that is well conserved among other members of the FZ family. The CRD, comprised of ˜110 amino acid residues, including 10 invariant cysteines, is the putative binding site for Wnt ligands. Bhanot et al., Nature 382, 225-30 (1996).
[0011] In organisms including frogs, fruit flies, and mice, proteins including Wingless. Armadillo, and Frizzled form part of a signaling cascade that controls crucial events during early embryonic development—particularly gastrulation, the process by which a hollow ball of embryonic cells collapses in on itself, forming the major embryonic tissues. In vertebrates, the signaling pathway—headed by the Wnt family of growth factors contribute to the formation of body axis and the proper development of the central nervous system, kidneys, and limbs. When it is activated inappropriately in adult cells, the pathway can precipitate the formation of tumors. During gastrulation, Fz family members may interact with Wnt to control the proper development of the nervous system and muscles. The coupling of Wnt and Frizzled activates a pathway that leads to the expression of a set of Wnt-responsive genes, including those that encode the transcription factors such as Engrailed and Siamois.
[0012] When Wnt mRNA is injected into Xenopus embryos in the 4-8 cell stage, the tadpoles develop a second body axis: They can duplicate all or part of the nervous systems from head to tail, and many of their organs are duplicated. Interestingly, during gastrulation, a Wnt family member known as Xwnt-8 serves to “ventralize” the embryo—steering cells in the mesoderm toward forming muscle. Injecting Frzb mRNA into a developing Xenopus embryo prior to gastrulation inhibits muscle formation, generating tadpoles that are stunted in appearance, with shortened trunks due to the lack of muscle tissue. The embryos also have enlarged heads, because an abnormal number of mesodermal cells adopt a dorsal fate. Knockout mice have already helped researchers understand a few of the various roles that Wnts play in development. To date, scientists have identified 16 different Wnts that function in vertebrate development. Many Wnts appear to be involved in directing the development of the central nervous system (CNS). Others control the formation of nephrons in the kidney and the proper development of the limbs.
[0013] The existence of molecules that have a FZ CRD but lack the seven transmembrane motif and cytoplasmic tail suggests that there is a subfamily of proteins that function as regulators of Wnt activity. Little is known about the activity of SDF5, which was cloned using the signal sequence trap method. FRZB is a heparin-binding molecule thought to be involved in skeletal morphogenesis. Recently Rattner et al. cloned cDNAs encoding the murine homologs of Fz family members, and showed that, when artificially linked to the plasma membrane via a glycolipid anchor, SDF5 and FRZB conferred cellular binding to Wg. Rattner et al., P.N.A.S. 94, 2859-2863 (1997).
[0014] The disregulation of Wnt pathways appears to be a factor in aberrant growth and development. Mutations in β-catenin, a protein that accumulates when the Wnt pathway is activated, are associated with tumor development in human colon cancers and melanomas. β-catenins couple with other cellular transcription factors and help to activate Wnt-responsive genes. These results confirm that the Wnt-signaling pathway can play an important role in the embryo and the adult. Ultimately, Wnt transmits its signal by allowing β-catenin to accumulate in the cell cytoplasm. There, β-catenin binds to members of the Tcf-Lef transcription factor family and translocates to the nucleus. When Wnt is absent, β-catenin instead forms a complex with glycogen synthase kinase-3 (GSK-3) and the adenomatous polyposis coli (APC) tumor-suppressor protein. This interaction is associated with the phosphorylation of β-catenin, marking it for ubiquitination and degradation. Wnt permits the accumulation of β-catenin by inhibiting the function of GSK-3. The mutations that drive tumor formation follow a similar strategy. Mutations in APC render the tumor-suppressor protein unable to bind to β-catenin, which remains unphosphorylated and accumulates in the cell, turning on Wnt-responsive genes.
[0015] Given the potential complexity of interactions between the multiple members of Wnt and FZ families, additional mechanisms might exist to modulate Wnt signaling during specific periods of development or in certain tissues. What is needed in the art is the identification and characterization of novel effectors of the processes which are related to cellular growth and development. The identification of such mechanisms and in particular, the effectors of these mechanisms is important for understanding and modulating the processes of cellular regulation.
SUMMARY OF THE INVENTION
[0016] The invention includes nucleotide sequences that encode a novel polypeptide, designated in the present application as “FRP” (Frizzled Related Protein), which is a secreted antagonist of the Wnt signaling pathway and exhibits a number of characteristics which make it a useful tool for studying cell growth and differentiation as well as oncogenesis. As such, this novel protein has a variety of applications in the identification, characterization and regulation of activities associated with cellular function as well as processes associated with oncogenesis.
[0017] The invention provides “FRP” (Frizzled Related Protein) polypeptides and fragments thereof and polynucleotide sequences encoding FRP polypeptides. The invention further provides antibodies which are specific for FRP polypeptides and animals having FRP transgenes. Moreover, the invention provides methods of producing FRP polypeptides and polynucleotide sequences. In addition, the invention provides methods of assaying for FRP in a sample as well as methods for detecting FRP binding partners.
[0018] In one embodiment, the invention provides isolated nucleic acid molecules which encode FRP polypeptides. For example, the isolated nucleic acid can include DNA encoding FRP polypeptide having amino acid residues 1 to 313 of FIG. 1, or is complementary to such encoding nucleic acid sequence, and remains stably bound to it under at least moderate, and optionally, under high stringency conditions. In another embodiment, the invention provides a vector comprising a gene encoding a FRP polypeptide. A host cell comprising such a vector is also provided. By way of example, the host cells may be E. coli, yeast or mammalian cells. A process for producing FRP polypeptides is further provided and comprises culturing host cells under conditions suitable for expression of FRP. If desired, the FRP may be recovered.
[0019] In another embodiment, the invention provides isolated FRP polypeptide. In one embodiment, FRP of the invention comprises 313 amino acids and includes a signal sequence, Wnt binding domain, a hyaluronic acid binding domain and potential asparagine-linked glycosylation sites. In particular, the invention provides isolated native sequence FRP polypeptide, which in one embodiment, includes an amino acid sequence comprising residues 1 to 313 of FIG. 1. In a related embodiment, the invention provides chimeric molecules comprising FRP polypeptide fused to a heterologous polypeptide or amino acid sequence. An example of such a chimeric molecule is a factor which includes a FRP fused to a polyhistidine polypeptide sequence. In another embodiment, the invention provides a non-human transgenic animal whose somatic and germ cells contain a transgene comprising human FRP. In yet another embodiment, the invention provides a polypeptide capable of specifically binding a FRP polypeptide such as an antibody specific for a FRP polypeptide. Optionally, the antibody is a monoclonal antibody.
[0020] Also included in the invention is a method for regulating cell signaling pathways by inhibiting the interaction of Wnt with Fz receptors by blocking this interaction with FRP molecules. The invention also provides methods for determining the presence of FRP molecules in a sample. The invention also provides a method for determining the presence of Wnt molecules in a sample by screening the sample with FRP. In addition, the invention provides a method for monitoring the course of a neoplastic condition by quantitatively determining the presence of Wnt molecules in a sample by screening the sample with FRP.
[0021] In other embodiments, the invention provides methods for using FRP polypeptides and nucleic acids for studying and modulating mechanisms involved in cellular proliferation. In one embodiment, the invention provides a method of modulating cellular phenotype by controlling the level of FRP expression within the cell. In a more specific embodiment, the invention provides a method of inhibiting cellular proliferation and/or differentiation by exposing a cell to FRP.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1A shows an SDS/PAGE analysis of heparin-Sepharose purified FRP.
[0023] [0023]FIG. 1B shows a restriction endonuclease map with representations of the human FRP cDNA clones and the coding region of the gene.
[0024] [0024]FIG. 1C shows the predicted FRP amino acid sequence (standard single-letter code).
[0025] [0025]FIG. 2 shows a comparison of the CRDs of FRP and other members of the FZ family.
[0026] [0026]FIG. 3 shows a northern blot analysis showing FRP mRNA expression in normal human adult and embryonic tissues, and in cultured cells.
[0027] [0027]FIG. 4 shows the chromosomal localization of the FRP gene by fluorescent in situ hybridization.
[0028] [0028]FIG. 5 shows a southern blot analysis of FRP genomic sequences in different species.
[0029] [0029]FIG. 6 shows the biosynthesis of FRP in M426 cells via a pulse-chase experiment performed with metabolically labeled cells incubated either in the absence or presence of heparin.
[0030] [0030]FIG. 7 shows the dorsal axis duplication in Xenopus embryos in response to varying combinations of Wnt and FRP transcripts.
[0031] [0031]FIGS. 8A, 8B and 8 C show nucleic acid sequences which encode FRP.
[0032] [0032]FIG. 9 shows the binding of FRP to biotinylated hyaluronic acid in a transblot assay under either nonreducing (−) or reducing (=) conditions.
[0033] [0033]FIG. 10 shows the competition of BHA binding to FRP by various proteoglycans, C.S. is chondroitin sulfate, H.A. is hyaluronic acid, H.A. oligo is hyaluronic acid oligosaccaride. The Ab control consists of a western blot of FRP with rabbit polyclonal antiserum raised against FRP synthetic peptide.
[0034] [0034]FIG. 11 shows the nucleic acid sequence of a FRP 5′ flanking genomic sequences.
[0035] [0035]FIG. 12A shows the production of recombinant FRP.
[0036] [0036]FIG. 12B shows immunoblotting of recombinant FRP with peptide antiserum.
[0037] [0037]FIG. 12C shows a polyacrrylamide gel of silver stained recombinant FRP.
[0038] [0038]FIG. 13A shows the interaction between recombinant FRP and Wg in an ELISA format.
[0039] [0039]FIG. 13B shows the immunoblotting of Wg.
[0040] [0040]FIG. 14 shows an ELISA type competition assay showing the ability of soluble FRP to block Wg binding to FRP coated cells.
[0041] [0041]FIG. 15 shows the effects of varying the concentration of heparin in crosslinking reactions between 125 I-FRP and Wg, with the crosslinked molecules being immunoprecipitated with an anti-Wg monoclonal antibody and separated by gel electrophoresis.
[0042] [0042]FIG. 16 shows the effects of varying the concentration of unlabelled FRP or FRP derivatives in crosslinking reactions between 125 I-FRP and Wg, with the crosslinked molecules being immunoprecipitated with an anti-Wg monoclonal antibody and separated by gel electrophoresis.
DETAILED DESCRIPTION OF THE INVENTION
[0043] Definitions
[0044] As used in this application, the following words or phrases have the meanings specified.
[0045] The terms “FRP polypeptide” and “FRP” when used herein encompass native sequence FRP and FRP variants (which are further defined herein). The FRP may be isolated from a variety of sources, such as from human tissue types or from another source, or prepared by recombinant or synthetic methods.
[0046] The FRP polypeptide, which may be a fragment of a native sequence, contains a Wnt binding domain. Typically, the FRP polypeptide also includes a hyaluronic acid binding domain.
[0047] A “native sequence FRP” is a polypeptide having the same amino acid sequence as an FRP derived from nature. Such native sequence FRP can be isolated from nature or can be produced by recombinant or synthetic means. The term “native sequence FRP” specifically encompasses naturally-occurring variant forms (e.g., alternatively spliced forms) and naturally-occurring allelic variants of the FRP. In one embodiment of the invention, the native sequence FRP is a mature or full-length native sequence FRP polypeptide comprising amino acids 1 to 313 of FIG. 1.
[0048] “FRP variant” means a functionally active FRP as defined below having at least about 80% amino acid sequence identity with FRP, such as the FRP polypeptide having the deduced amino acid sequence shown in FIG. 1 for a full-length native sequence FRP. Such FRP variants include, for instance, FRP polypeptides wherein one or more amino acid residues are added, or deleted, at the N- or C-terminus of the sequence of FIG. 1. Ordinarily, a FRP variant will have at least about 80% or 85% amino acid sequence identity with native FRP sequences, more preferably at least about 90% amino acid sequence identity. Most preferably a FRP variant will have at least about 95% amino acid sequence identity with native FRP sequence of FIG. 1.
[0049] “Percent (%) amino acid sequence identity” with respect to the FRP sequences identified herein is defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the FRP sequence, after aligning the sequences in the same reading frame and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared.
[0050] “Percent (%) nucleic acid sequence identity” with respect to the FRP sequences identified herein is defined as the percentage of nucleotides in a candidate sequence that are identical with the nucleotides in the FRP sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Alignment for purposes of determining percent nucleic acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared.
[0051] The term “epitope tagged” when used herein refers to a chimeric polypeptide comprising FRP, or a functional fragment thereof, fused to a “tag polypeptide”. The tag polypeptide has enough residues to provide an epitope against which an antibody can be made, or which can be identified by some other agent, yet is short enough such that it does not interfere with activity of the FRP. The tag polypeptide preferably also is sufficiently unique so that the antibody does not substantially cross-react with other epitopes. Suitable tag polypeptides generally have at least six amino acid residues and usually between about 8 to about 50 amino acid residues (preferably, between about 10 to about 20 residues).
[0052] “Isolated,” when used to describe the various polypeptides disclosed herein, means polypeptide that has been identified and separated and/or recovered from a contaminating component of its natural environment. Contaminant components of its natural environment are materials that would typically interfere with diagnostic or therapeutic uses for the polypeptide. and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes. In preferred embodiments, the polypeptide will be purified to a degree sufficient to obtain N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or to homogeneity by SDS-PAGE under non-reducing or reducing conditions using Coomassie blue or silver stain. Isolated polypeptide includes polypeptide in situ within recombinant cells, since at least one component of the FRP natural environment will not be present. Ordinarily, however, isolated polypeptide will be prepared by at least one purification step (referred to herein as an “isolated and purified polypeptide”).
[0053] An “isolated” FRP nucleic acid molecule is a nucleic acid molecule that is identified and separated from at least one contaminant nucleic acid molecule with which it is ordinarily associated in the natural source of the FRP nucleic acid. An isolated FRP nucleic acid molecule is other than in the form or setting in which it is found in nature. Isolated FRP nucleic acid molecules therefore are distinguished from the FRP nucleic acid molecule as it exists in natural cells. However, an isolated FRP nucleic acid molecule includes FRP nucleic acid molecules contained in cells that ordinarily express FRP where, for example, the nucleic acid molecule is in a chromosomal location different from that of natural cells.
[0054] The term “control sequences” refers to DNA sequences necessary for the expression of an operably linked coding sequence in a particular host organism. The control sequences that are suitable for prokaryotes, for example, include a promoter, optionally an operator sequence, and a ribosome binding site. Eukaryotic cells are known to utilize promoters, polyadenylation signals, and enhancers.
[0055] Nucleic acid is “operably linked” when it is placed into a functional relationship with another nucleic acid sequence. For example, DNA for a presequence or secretory leader is operably linked to DNA for a polypeptide if it is expressed as a preprotein that participates in the secretion of the polypeptide; a promoter or enhancer is operably linked to a coding sequence if it affects the transcription of the sequence; or a ribosome binding site is operably linked to a coding sequence if it is positioned so as to facilitate translation. Generally, “operably linked” means that the DNA sequences being linked are contiguous, and, in the case of a secretory leader, contiguous and in reading phase. However, enhancers do not have to be contiguous. Linking may be accomplished by ligation at convenient restriction sites. If such sites do not exist, the synthetic oligonucleotide adaptors or linkers may be used in accordance with conventional practice.
[0056] “Polynucleotide” and “nucleic acid” refer to single or double-stranded molecules which may be DNA, comprised of the nucleotide bases A, T, C and G, or RNA, comprised of the bases A, U (substitutes for T), C, and G. The polynucleotide may represent a coding strand or its complement. Polynucleotide molecules may be identical in sequence to the sequence which is naturally occurring or may include alternative codons which encode the same amino acid as that which is found in the naturally occurring sequence (See. Lewin “Genes V” Oxford University Press Chapter 7. pp. 171-174 (1994)). Furthermore, polynucleotide molecules may include codons which represent conservative substitutions of amino acids as described. The polynucleotide may represent genomic DNA or cDNA.
[0057] “Polypeptide” refers to a molecule comprised of amino acids which correspond to those encoded by a polynucleotide sequence which is naturally occurring. The polypeptide may include conservative substitutions where the naturally occurring amino acid is replaced by one having similar properties, where such conservative substitutions do not alter the function of the polypeptide (See, Lewin “Genes V” Oxford University Press Chapter 1, pp.: 9-13 (1994)).
[0058] The term “antibody” is used in the broadest sense and specifically covers single anti-FRP monoclonal antibodies (including agonist, antagonist, and neutralizing antibodies) and anti-FRP antibody compositions with polyepitopic specificity as well as other recombinant molecules derived from these antibodies. The term “monoclonal antibody” as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for possible naturally-occurring mutations that may be present in minor amounts.
[0059] As used herein, “non-FRP binding molecule” is defined as a molecule which does not bind FRP.
[0060] As used herein a “binding domain” means that portion or portions of a molecule which confer the ability to bind its target.
[0061] As used herein “blocking” means to interfere with the binding of one molecule to another.
[0062] As used herein a “sample” means any sample which may contain molecule of interest and includes but is not limited to (1) biological fluids such as solutions comprising blood, lymph, saliva and/or urine and (2) tissues derived from brain, lung, muscle and/or bone.
[0063] In order that the invention herein described may be more fully understood, the following description is set forth.
[0064] Identification of a Novel Wnt Binding Ligand.
[0065] Disclosed herein is a novel human gene product which resembles FZ proteins in that it possesses a conserved FZ CRD, a putative binding domain for Wnt ligands. In contrast to the original members of the FZ family, FRP lacks any transmembrane region or cytoplasmic domain required to transduce Wnt signaling inside the cell. Because it is preferentially distributed to the cell surface or matrix, it is well-positioned to interact with Wnt proteins. Findings disclosed herein indicate that in Xenopus embryos FRP inhibits Wnt-dependent axial duplication when various Wnts and FRP are co-expressed. FRP behaves like a dominant-negative receptor in this model system, similar to the effect of the secreted NH2-terminal ectodomain of human FZ5 on axis duplication by XWnt-5A and hFZ5 (He et al. Science 275, 1652-1654 (1997)).
[0066] The existence of other molecules besides FRP that have a FZ CRD but lack the seven transmembrane motif and cytoplasmic tail suggests that there is a subfamily of proteins that function as regulators of Wnt activity. Little is known about the activity of SDF5, which was cloned using the signal sequence trap method (Shirozu et al., (1996) Genomics 37, 273-280). FRZB is a heparin-binding molecule thought to be involved in skeletal morphogenesis (Hoang, B., Moos, M., Jr., Vukicevic, S. & Luyten, F. P. (1996) J Biol Chem 271, 26131-7). Recently Rattner et al. cloned cDNAs encoding the murine homologs of SDF5, FRZB and FRP, and showed that, when artificially linked to the plasma membrane via a glycolipid anchor, SDF5 and FRZB conferred cellular binding to Wg (Rattner, A., Hsieh, J. C., Smallwood, P. M., Gilbert, D. J., Copeland, N. G., Jenkins, N. A. & Nathans, J. (1997) Proc Natl Acad Sci USA 94, 2859-2863). Thus, it now appears likely that these molecules can interact with Wnt proteins and modulate their activity.
[0067] Compositions of the Invention.
[0068] This invention provides the isolation of human FRP which includes a Wnt binding site (also referred to herein as the cysteine rich domain (CRD), the binding site for Wnt ligands, and the FZ CRD motif) and a hyaluronic acid binding sequence (also referred to herein as the hyaluronic acid binding site and the hyaluronic acid binding domain). FRP is a secreted antagonist to Wnt signaling. In addition, the invention provides FRP polypeptide products of the FRP gene. The invention also provides methods for using the expressed FRP to regulate Wnt signaling, and as a detection means for Wnt proteins and associated processes.
[0069] The present invention provides the first human protein product of the FRP gene. In one embodiment, human FRP of the invention includes 313 amino acids. Further it includes a signal sequence, a Wnt binding domain, a hyaluronic acid binding sequence and potential asparagine-linked glycosylation sites. In a preferred embodiment, a human FRP includes a Wnt binding domain as shown in the large shaded region of FIG. 1C and a hyaluronic acid binding sequence as shown in the small shaded region of FIG. 1C. The amino acid sequence of this FRP is shown in FIG. 1C.
[0070] In another embodiment, a FRP can be joined to another molecule. The FRP may be fused a variety of known fusion protein partners that are well known in the art such as maltose binding protein, LacZ, thioredoxin or an immunoglobulin constant region ( Current Protocols In Molecular Biology, Volume 2, Unit 16, Frederick M. Ausubul et al. eds., 1995; Linsley, P. S., Brady, W., Urnes, M., Grosmaire, L., Damle, N., and Ledbetter, L.(1991) J Exp. Med. 174, 561-566). In a preferred embodiment, this fusion partner is a non-FRP binding molecule so as to prevent difficulties associated with intramolecular interactions. In the alternative, the FRP can be joined to a detectable label such as a radioactive isotope such as I 125 or P 32 , an enzyme such as horseradish peroxidase or alkaline phosphatase a fluorophore such as fluorescein isothiocyanate or a chromophore ( Current Protocols In Molecular Biology, Volume 2, Units 10,11 and 14, Frederick M. Ausubul et al. eds., 1995; Molecular Cloning, A Laboratory Manual, § 12, Tom Maniatis et al. eds., 2d ed. 1989).
[0071] The invention also provides peptides and polypeptides having a specific portion of the FRP such as the Wnt binding domain or the hyaluronic acid binding domain (Current Protocols In Molecular Biology, Volume I, Unit 8, Ausubul et al. eds., 1995; Solid Phase Peptide Synthesis, The Peptides Volume II, G. Barany et al., 1980). As with FRP and FRP fusion proteins, these polypeptides can be joined to amino acid tags such as Hemaglutinin or polyhistidine sequences (Krebs et al., Protein Exp. Pur. 6(6), 780-788 (1995); Canfield, V. A., Norbeck, L., and Leveson, R., (1996) Biochemistry 35(45), 14165-14172), larger molecules such as immunoglobulin constant regions, various functional domains from other proteins and known fusion proteins partners ( Current Protocols In Molecular Biology, Volume 2, Unit 16, Frederick M. Ausubul et al. eds., 1995; Linsley, P. S., Brady, W., Urnes, M., Grosmaire, L., Damle, N., and Ledbetter, L. (1991) J. Exp. Med. 174, 561-566). In the alternative, the polypeptide can be joined to a detectable label such as a radioactive isotope, an enzyme, a fluorophore or a chromophore.
[0072] The polypeptides of the invention can combine in a wide variety of known reagents; typically as a composition comprising an FRP or portion thereof, included therein in a pharmaceutically acceptable carrier such as dextran in a suitable buffer ( Current Protocols In Molecular Biology, Volume 3, Appendix A, Frederick M. Ausubul et al. eds., 1995; The Pharmacological Basis of Therapeutics, Alfred G. Gilman et al eds., 8th ed. 1993).
[0073] The invention includes single and double stranded nucleic acid molecules having human FRP gene sequences. An illustrative example of such a molecule is shown in FIG. 8. Alternatively, the nucleic acid molecule is represented by the restriction endonuclease map shown in FIG. 1B. These nucleic acid molecules can be RNA such as mRNA or DNA such as cDNA. In a preferred embodiment, the nucleic acid molecule or a hybrid thereof can be joined to a detectable label or tag such as P 32 , biotin or digoxigenein, ( Current Protocols In Molecular Biology, Volume I, Unit 3, Frederick M. Ausubul et al. eds., 1995).
[0074] In another embodiment, a nucleic acid molecule can include a specific portion of the FRP molecule such as the untranslated regulatory regions, the Wnt binding domain or the hyaluronic acid binding domain In one such embodiment, the nucleic acid molecule is a deletion mutant which encodes a portion of the region coding for the n-terminus or c-terminus of the FRP protein. In an illustrative embodiment of such a deletion mutant, the deleted sequence encodes the putative FRP signal sequence from FIG. 1C. In another embodiment, the nucleic acid molecule is a deletion mutant in which an internal portion of the FRP coding region has been removed. These FRP molecules can be joined to other nucleic acid molecules such as those encoding fusion protein partners ( Molecular Cloning, A Laboratory Manual, § 14 and Appendix F, Tom Maniatis et al. eds., 2d ed. 1989). These specific nucleic acid molecules may also be joined to a tag or a detectable label.
[0075] Another embodiment provides a complementary nucleic acid probe which specifically hybridizes to FRP nucleic acid sequences ( Molecular Cloning, A Laboratory Manual, § 7, 9, 14 and Appendix F, Tom Maniatis et al. eds., 2d ed. 1989). In a preferred embodiment, such a probe hybridizes with the Wnt binding domain which encodes amino acids 57-166 as shown in FIG. 1C. For example, the isolated nucleic acid can include DNA encoding FRP polypeptide having amino acid residues 57-166 of FIG. 1C, or is complementary to such encoding nucleic acid sequence, and remains stably bound to it under at least moderate, and optionally, under high stringency conditions. Those skilled in the art appreciate that the stringency of the conditions are manipulated by altering the ionic strength and/or temperature of the hybridization, with for example, conditions of higher stringency employing hybridization conditions wherein the complexes are washed under conditions of lower ionic strength and higher temperatures. Thus, prehybridization and hybridization conditions of 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmon sperm DNA, and either 50, 35 or 25% formamide illustrate high, medium and low stringencies, respectively. Variations on such condition are well known in the art (see e.g. U.S. Pat. Nos. 5,688,663 and 5,429,921).
[0076] Another embodiment provides an antisense nucleic acid which specifically hybridizes to FRP mRNA (Chen, Z., Fischer. R., Riggs, C.. Rhim, J. and Lautenberger, J. (1997) Cancer Research 57, 2013-2019; Aviezer D., Iozzo, R. V., Noonan, D., and Yayon, a., (1997). Mol. Cell Biol. 17(4), 1938-1946). Antisense technology entails the administration of exogenous oligonucleotides which bind to a target polynucleotide located within the cells. The term “antisense” refers to the fact that such oligonucleotides are complementary to their intracellular targets, e.g., FRP. See for example, Jack Cohen, OLIGODEOXYNUCLEOTIDES, Antisense Inhibitors of Gene Expression. CRC Press, 1989; and Synthesis 1:1-5 (1988). The FRP antisense oligonucleotides of the present invention include derivatives such as S-oligonucleotides (phosphorothioate derivatives or S-oligos, see, Jack Cohen, supra) which exhibit enhanced cancer cell growth inhibitory action.
[0077] S-oligos (nucleoside phosphorothioates) are isoelectronic analogs of an oligonucleotide (O-oligo) in which a nonbridging oxygen atom of the phosphate group is replaced by a sulfur atom. The S-oligos of the present invention may be prepared by treatment of the corresponding O-oligos with 3H-1,2-benzodithiol-3-one-1,1-dioxide which is a sulfur transfer reagent. See Iyer, R. P. et al, J. Org. Chem. 55:4693-4698 (1990); and Iyer, R. P. et al., J. Am. Chem. Soc. 112:1253-1254 (1990), the disclosures of which are fully incorporated by reference herein.
[0078] The FRP antisense oligonucleotides of the present invention may be RNA or DNA which is complementary to and stably hybridizes with the first 100 N-terminal codons or last 100 C-terminal codons of the FRP genome or the corresponding mRNA. While absolute complementarity (i.e. a complementary interaction between all polynucleotide moieties) of antisense oligonucleotides is not required, high degrees of complementarity are preferred. Use of an oligonucleotide complementary to this region allows for the selective hybridization to FRP mRNA and not to mRNA specifying other regulatory subunits of protein kinase. Preferably, the FRP antisense oligonucleotides of the present invention are a 15 to 30-mer fragment of the antisense DNA molecule having which hybridizes to FRP mRNA. Optionally, FRP antisense oligonucleotide is a 30-mer oligonucleotide which is complementary to a region in the first 10 N-terminal codons and last 10 C-terminal codons of FRP. Alternatively the antisense molecules are modified to employ ribozymes in the inhibition of FRP expression. L. A. Couture & D. T. Stinchcomb; Trends Genet 12:510-515 (1996).
[0079] The invention further provides an expression vector such as bacteriophage lambda gt11, plasmid vectors such as pcDNA, CDM8 and PNTK or retroviral vectors such as those of the pBABE series comprising the FRP cDNA or a portion thereof ( Current Protocols In Molecular Biology, Volume I, Units 5, 9, 12, Frederick M. Ausubul et al. eds., 1995). Additionally, the invention provides a host vector system in which the expression vector is transfected into a compatible host cell including bacterial strains such as the DH5α strain of E. coli, yeast strains such as EGY48, animal cell lines such as CHO cells and human cells such as HELA cells ( Current Protocols In Molecular Biology, Volume II, Units 13-16, Frederick M. Ausubul et al. eds., 1995; Molecular Cloning, A Laboratory Manual, § 16 and 17, Tom Maniatis et al. eds., 2d ed. 1989). Additionally, the invention provides a method of producing a protein comprising growing the transfected host cell, thereby producing the protein that may be recovered and utilized in a wide variety of applications ( Current Protocols In Molecular Biology, Volume II, Unit 16, Frederick M. Ausubul et al. eds., 1995).
[0080] As discussed in Example 7, an illustrative embodiment of a recombinant expression system is the MDCK/FRP recombinant expression system. Optimization of the MDCK/FRP recombinant expression system may be carried out by techniques known in the art. For example, immunological methods may be employed to screen subpopulations of transfectants to measure the amount of FRP released into the medium. By successive screening and subculturing, clonal lines expressing greater amounts of FRP protein may be obtained. In addition, the illustrative regimen for harvesting conditioned medium involves subculturing into a large number of T-175 flasks and cycling monolayers from serum-containing to serum-free medium several times may be streamlined by utilizing alternative devices such as cell factories and/or microcarriers, and then determine whether multiple successive rounds of FRP-rich, serum-free conditioned medium can be collected once confluent monolayers are generated with serum-containing medium. Such measures can reduce the time and cost of producing large quantities of recombinant protein to be used for structural analysis, biochemical and biological studies.
[0081] The asymmetry of FRP elution in the heparin-HPLC optical density profile, and the breadth of the FRP-crossreactive bands suggest that current preparations of recombinant protein are heterogeneous (FIG. 12). This is also evident in naturally occurring FRP, as amino-terminal sequence analysis revealed two distinct sequences that differed from each other by a three-amino acid stagger. Finch. et al., P.N.A.S. 94: 6770-6775 (1997). To identify the source of this heterogeneity amino acid sequence analysis of purified recombinant FRP protein can performed to evaluate the purity of the preparation and indicate whether such differences account for at least some of the apparent heterogeneity. Given the presence of two potential asparagine-linked glycosylation sites in the FRP sequence, variation in glycosylation also might contribute to heterogeneity. This possibility can be tested by expressing site-directed mutants lacking the glycosylation sites; the mobility and breadth of immunocrossreactive bands corresponding to these derivatives will indicate whether FRP normally is glycosylated at these sites and whether this is responsible for heterogeneity. The resolution of putative FRP variants by additional chromatography (ion exchange or hydrophobic interaction, for instance) or their elimination by removal of glycosylation sites is also possible using art accepted techniques and will facilitate structural analysis by methods such as X-ray diffraction or NMR that require homogeneous preparations.
[0082] The MDCK/FRP expression system can be used to produce FRP derivatives for structural analysis. Besides mutants lacking glycosylation sites, truncated variants may can be expressed to assess the significance of different structural elements. While the epitopes and regions associated with the function and integrity of the cysteine-rich domain (CRD) are of significant interest, other regions of the molecule presumably responsible for binding to proteoglycan can also be examined. Such structural studies can be used to determine the disulfide-bonding pattern in the CRD, and consequently, to engineer substitutions of paired cysteine residues to determine the significance of individual disulfide bond-dependent peptide loops. Derivatives can be tested in Wnt-binding ELISAs ( for example as shown in FIG. 13) and in biological assays involving β-catenin stabilization or other manifestations of Wnt activity. Miller et al., Genes Dev. 10: 2527-2539, (1996). The ELISA format disclosed in Example 8 is particularly well suited for a quantitative comparison of the FRP analogs. Because the heparin-binding and immunological properties of the derivatives will vary, one can express them in pcDNA vectors designed to add histidine and Myc tags to the recombinant protein. In this way, it is possible to purify the various derivatives on nickel-affinity resin and visualize them with antibody directed against the Myc or histidine epitopes.
[0083] Reports indicate that there are several other secreted Frizzled-related proteins of similar size and perhaps function. (See e.g., Rattner, et al., P.N.A.S. 94:2859-2863 (1997)). The MDCK/pcDNA expression system is well suited for the production of other secreted FRP molecules. In this way one can compare and contrast the binding and biological properties of multiple secreted FRPs to better understand their unique functions.
[0084] Notwithstanding the results obtained with FRP expression in MDCK cells, other recombinant systems may prove more useful for certain applications. For example, for NMR solution analysis, proteins must be uniformly labeled with various non-standard isotopes ( 2 H, 3 C, 5 N). The medium required to achieve this labeling in mammalian cell culture is very expensive. As an alternative, one may express CRD-containing constructs in yeast ( Pichia pasteuris ), bacteria such as E. coli or baculovirus/insect cell expression systems, where isotope-labeling should be more straightforward.
[0085] Further, in accordance with the practice of this invention, FRP molecules of the invention can have amino acid substitutions in the amino acid sequence shown in FIG. 1C ( Current Protocols In Molecular Biology, Volume I, Unit 8, Frederick M. Ausubul et al. eds., 1995). The only requirement being that substitutions result in human FRP that retains the ability to bind the Wnt molecule. These amino acid substitutions include, but are not necessarily limited to, amino acid substitutions known in the art as “conservative”.
[0086] For example, it is a well-established principle of protein chemistry that certain amino acid substitutions, entitled “conservative amino acid substitutions,” can frequently be made in a protein without altering either the conformation or the function of the protein. Such changes include substituting any of isoleucine (I), valine (V), and leucine (L) for any other of these hydrophobic amino acids; aspartic acid (D) for glutamic acid (E) and vice versa; glutamine (Q) for asparagine (N) and vice versa; and serine (S) for threonine (T) and vice versa. Other substitutions can also be considered conservative, depending on the environment of the particular amino acid and its role in the three-dimensional structure of the protein. For example, glycine (G) and alanine (A) can frequently be interchangeable, as can alanine and valine (V). Methionine (M), which is relatively hydrophobic, can frequently be interchanged with leucine and isoleucine, and sometimes with valine. Lysine (K) and arginine (R) are frequently interchangeable in locations in which the significant feature of the amino acid residue is its charge and the differing pK's of these two amino acid residues are not significant. Still other changes can be considered “conservative” in particular environments.
[0087] FRP derivatives can be made using methods known in the art such as site-directed mutagenesis, alanine scanning, and PCR mutagenesis. Site-directed mutagenesis [Carter et al., Nucl. Acids Res., 13:4331 (1986); Zoller et al., Nucl. Acids Res., 10:6487 (1987)], cassette mutagenesis [Wells et al., Gene, 34:315 (1985)], restriction selection mutagenesis [Wells et al., Philos. Trans. R. Soc. London SerA, 317:415 (1986)] or other known techniques can be performed on the cloned DNA to produce the FRP variant DNA. Scanning amino acid analysis can also be employed to identify one or more amino acids along a contiguous sequence. Among the preferred scanning amino acids are relatively small, neutral amino acids. Such amino acids include alanine, glycine, serine, and cysteine. Alanine is typically a preferred scanning amino acid among this group because it eliminates the side-chain beyond the beta-carbon and is less likely to alter the main-chain conformation of the variant. Alanine is also typically preferred because it is the most common amino acid. Further, it is frequently found in both buried and exposed positions [Creighton, The Proteins, (W. H. Freeman & Co., N.Y.); Chothia, J. Mol. Biol., 150:1 (1976)]. If alanine substitution does not yield adequate amounts of variant, an isoteric amino acid can be used.
[0088] As discussed above, redundancy in the genetic code permits variation in FRP gene sequences. In particular, one skilled in the art will recognize specific codon preferences by a specific host species and can adapt the disclosed sequence as preferred for a desired host. For example, preferred codon sequences typically have rare codons (i.e., codons having a useage frequency of less than about 20% in known sequences of the desired host) replaced with higher frequency codons. Codon preferences for a specific organism may be calculated, for example, by utilizing codon usage tables available on the INTERNET at the following address: http://www.dna.affrc.go.jp/˜nakamura/codon.html. Nucleotide sequences which have been optimized for a particular host species by replacing any codons having a useage frequency of less than about 20% are referred to herein as “codon optimized sequences.”
[0089] Additional sequence modifications are known to enhance protein expression in a cellular host. These include elimination of sequences encoding spurious polyadenylation signals, exon/intron splice site signals, transposon-like repeats, and/or other such well-characterized sequences which may be deleterious to gene expression. The GC content of the sequence may be adjusted to levels average for a given cellular host, as calculated by reference to known genes expressed in the host cell. Where possible, the sequence may also be modified to avoid predicted hairpin secondary mRNA structures. Other useful modifications include the addition of a translational initiation consensus sequence at the start of the open reading frame, as described in Kozak, Mol. Cell Biol., 9:5073-5080 (1989). Nucleotide sequences which have been optimized for expression in a given host species by elimination of spurious polyadenylation sequences, elimination of exon/intron splicing signals, elimination of transposon-like repeats and/or optimization of GC content in addition to codon optimization are referred to herein as an “expression enhanced sequence.”
[0090] The present invention also provides an antibody which specifically recognizes and binds an epitope on a FRP, e.g. the Wnt binding domain or the hyaluronic acid binding domain of an FRP ( Current Protocols In Molecular Biology, Volume II, Unit 11, Frederick M. Ausubul et al. eds., 1995; Kohler, G., and Milstein, C., Nature, (1975) 256, 495-497). A rabbit polyclonal antiserum raised against a synthetic peptide corresponding to a portion of the FRP amino-terminal sequence has been used for the detection of FRP by immunoblotting, immunoprecipitation and ELISA. A rabbit polyclonal antiserum raised against full-length recombinant FRP has also been generated. A related embodiment consists of an anti-idiotype antibody which specifically recognizes and binds antibody generated to an FRP epitope. Related embodiments further provide for single chain and humanized forms of these antibodies (U.S. Pat. No. 5,569,825 to Lonberg et al., issued Oct. 29, 1996; Bei, R., Schlom, J., and Kashmiri, S., (1995) J. Immunol. Methods 186(2) 245-255; Park, S., Ryu, C. J., Gripon, P., Guguen-Guillouzo, C., and Hong, H. J. (1996) Hybridoma 15(6) 435-441). These antibodies may be linked to a detectable label such as one selected from the group consisting of radioactive isotopes, enzymes, fluorophores or chromophores ( Current Protocols In Molecular Biology, Volume II, Units 11, 14, Frederick M. Ausubul et al. eds., 1995).
[0091] Methods of the Invention.
[0092] The invention further provides methods of modulating cellular development. In one embodiment, the method includes the steps of contacting a Wnt molecule with FRP or a portion of the FRP molecule. This contact blocks an interaction between the Wnt molecule and a Fz receptor, thereby inhibiting a cellular process such as proliferation and/or differentiation and/or migration (Tan, P., Anasetti, C., Hansen, J., Melrose, J., Brunvand, M., Bradshaw, J., Ledbetter, J. and Linsley, P., (1993) J. Exp. Med. 177, 165-173). In a preferred embodiment of this method, the cell is a tumor cell (Estrov, Z. Kurzrock, R., Estey, E. Wetzler, M., Ferrajoli, A., Harris, D., Blake, M., Guttermnan, J. U. and Talpaz, M. (1992) Blood 79(8) 1938-1945).
[0093] The invention further provides a method for blocking Wnt and Fz receptor binding. This method involves administering FRP to a subject. The FRP so administered must be in an amount sufficient to block the binding between a Wnt molecule and a Fz receptor.
[0094] The present invention also provides a method for modulating cellular differentiation in a subject. One such method includes administering cells transfected with an FRP gene ( Current Protocols In Molecular Biology, Volume I, Unit 9, Frederick M. Ausubul et al. eds., 1995). Once administered, these transfected cells express recombinant FRP in an amount sufficient to block the interactions between a Wnt molecule and Wnt receptor, thereby inhibiting cell proliferation and/or differentiation. In these methods, the FRP gene can be manipulated in one of a number of ways as is well known in the art such as through the use of a plasmid or viral vectors ( Molecular Cloning, A Laboratory Manual, § 1 and Appendix F, Tom Maniatis et al. eds.. 2d ed. 1989). The FRP gene can be inserted into donor cells by a nonviral physical transfection of DNA, by microinjection of RNA or DNA, by electroporation, via chemically mediated transfection or by one of a variety of related methods of manipulation ( Molecular Cloning, A Laboratory Manual, § 16, Tom Maniatis et al. eds., 2d ed. 1989).
[0095] Using the molecules disclosed herein. the invention provides methods to investigate the impact of FRP on effectors of Wnt signaling. In particular, one can measure the steady-state level of soluble β-catenin in cells exposed to Wnt stimulation in the presence or absence of FRP. As in a study showing that Drosophila Frizzled 2 (Df2) can mediate Wg-dependent stabilization of armadillo (Drosophila beta-catenin homolog), one can treat clone 8 cells expressing endogenous Dfz2 and/or Dfz2-transfected S2 cells with Wg-containing medium preincubated with FRP or vehicle control. Bhanot et al., Nature 382: 225-230, (1996). If FRP functions as a Wg antagonist in this cellular system, consistent with its effect in the Xenopus embryo dorsal axis duplication assay, lower levels of armadillo will be seen when cells are exposed to medium preincubated with FRP. Such a result was recently described in another experimental model: MCF-7 human mammary carcinoma cells transfected with an FRP construct showed a marked decrease in cellular β-catenin relative to vector control transfectants. Melkonyan, et al., P.N.A.S. 94:13636-13641 (1997) (in this article FRP was referred to as SARP2). Thus, one can test the ability of recombinant FRP protein to reduce the β-catenin content of this and other cell lines. If documented, this can serve as a convenient, semi-quantitative, functional assay of FRP derivatives. As additional markers of Wnt signaling are delineated, one can test the effect of FRP on these parameters. This can involve Tcf/LEF-1-beta-catenin-dependent gene expression (see e.g., Molenaar, et al., Cell 86:391-399 (1996). changes in cytoskeleton or cell cycle progression. The intent will be to determine whether all manifestations of Wnt signaling are blocked by FRP, or only certain pathways.
[0096] The invention further provides a method for determining the presence of FRP nucleic acid and peptide sequences in a sample. This method includes screening a sample with FRP nucleic acid molecules or antibodies via procedures such as reverse transcriptase Polymerase Chain Reaction, and northern and Southern and western protocols as is well known in the art ( Current Protocols In Molecular Biology, Volume I and III, Units 16, 2 and 4, Frederick M. Ausubul et al. eds., 1995).
[0097] As disclosed in Example 3 below, Northern blot analysis of RNA from adult and embryonic organs indicate that FRP is expressed widely, though not ubiquitously in humans. Subsequent in situ hybridization analysis of mouse embryonic tissue confirms this interpretation (see Example 3 below). By surveying the pattern of FRP expression during development and in the adult with a combination of in situ hybridization and immunohistochemistry, one can identify a set of contexts in which this gene is active. Additionally, one can extend the analysis to models of wound repair in which processes such as cell proliferation, migration and apoptosis are particularly active.
[0098] Similarly, FRP sequences and expression can be examined in tumor specimens. For example tumor samples can be screened for evidence of FRP mutations or hypermethylation of regulatory regions associated with the absence of gene expression (see e.g. Current Protocols In Molecular Biology, Volumes I and II, Units 3 and 12, Frederick M. Ausubul et al. eds., 1995).
[0099] A number of approaches that are well known in the art can be taken to study the regulation of FRP expression. An illustrative approach involves the use of various cytokines and/or growth conditions to assess the impact of different external agents or environmental factors on expression. Multiple FRP-expressing cells can be included in such analyses, as preliminary observations suggest that cells vary in their response to these kinds of stimuli. Complementary to these experiments is the identification and analysis of the FRP promoter region as shown in FIG. 11. Sequencing of the presumptive promoter lying 5′ upstream of the coding sequence can be followed by subcloning into reporter constructs and transfection into cell lines for functional analysis. Upon confirmation of promoter activity, one can pinpoint the sequences responsible for regulating expression by a combination of deletional analysis and computer-based searches to locate potential binding sites for transcription factors. If putative binding sites are identified, their relevance can be tested by expression of corresponding reporter constructs, gel shift and supershift experiments, and co-expression of promoter reporter constructs with mRNA promoting the expression of the corresponding transcription factor. Xu. et al., P.N.A.S. 93:834-838 (1996). The functionality of putative promoter sequences with respect to determining the spatiotemporal distribution of FRP expression can also be tested by using reporter constructs in transgenic mice.
[0100] The invention further provides a method for determining the presence of a Wnt molecule in a sample. This method includes adding a FRP to the sample. The FRP so added can recognize and bind Wnt molecule that is present in the sample. This binding results in a FRP/Wnt complex that can be detected. The presence of the complex is indicative of the presence of the Wnt molecule in the sample. In a variation of this method, detection includes contacting the complex with an antibody which recognizes and binds the complex ( Current Protocols In Molecular Biology, Volume II, Unit 11, Frederick M. Ausubul et al. eds., 1995). The antibody/complex so bound can be detected. The antibody can be either monoclonal or polyclonal. Further, the antibody can be bound to a matrix such agarose, sepharose, or a related type of bead ( Current Protocols In Molecular Biology, Volume II, Unit 11, Frederick M. Ausubul et al. eds., 1995). In addition, the antibody may be labeled with a detectable marker such as a radioactive isotope, an enzyme, a fluorophore or a chromophore.
[0101] The preparation of ample quantities of purified FRP protein as disclosed in Example 7 below is useful for studying the presumed interactions of FRP and Wnt polypeptides. With sufficient amounts of FRP, multiple experimental designs can be employed to test the hypothesis that FRP and Wnts engage in a direct interaction. The affinity and specificity of the suspected binding interactions can be determined, as well as the potential requirement for co-factors such as proteoglycan. Experimental models that rely on constitutive expression of FRP may yield important information about the effects of FRP on cell function. However, use of recombinant protein will enable one skilled in the art to control the timing and amount of FRP exposure, and consequently, assess its effects in a more quantitative manner. Moreover, a satisfactory recombinant expression system will be the cornerstone of detailed structure-function analysis.
[0102] As illustrated in Example 8, the invention provides methods to evaluate the interaction between FRP and FRP-binding partners. The results obtained with the FRP-Wg binding ELISA in Example 8 establish that this is a useful model for the study of FRP interactions with Wnt proteins. A variety of modifications of such studies are contemplated such as those that identify cofactors in these interactions. For example, the Wg content of purified and crude preparations can be normalized by immunoblot analysis, and the FRP-binding of both Wg samples can be compared in the ELISA disclosed in Example 8. Because the conditions used to purify Wg are relatively gentle, any appreciable decrease in binding activity of the enriched Wg preparation could be attributable to loss of a cryptic co-factor rather than denaturation of the Wg protein. If such a loss were observed, a leading candidate for the putative co-factor would be soluble glycosaminoglycan. To examine this, one can treat the crude material with heparitinases, or add exogenous proteoglycan to purified Wg in the ELISA and observing whether binding activity is restored.
[0103] Utilizing purified Wg one can estimate the affinity of the apparent FRP-Wg interaction. Either by using purified Wg directly in the FRP-binding ELISA, or simply to quantify the amounts of Wg in the starting material and bound in the ELISA microtiter well, it is possible to determine the concentration of bound versus free Wg in the assay and perform a Scatchard analysis to provide a useful indication of the affinity characterizing FRP-Wnt interactions.
[0104] As mentioned above, the ELISA format illustrated in Example 8 can be employed to examine Wnt binding of various FRP analogs. One can investigate the Wg-binding of FRP truncation mutants and site-directed variants lacking the asparagine-linked glycosylation sites. Further, the binding of additional site-directed FRP mutants and other secreted FRPs can be assessed. The substitution other Wnt family members for Wg in the binding assay will provide additional useful information.
[0105] Cell-free binding assays that complement the disclosed ELISA include ligand-receptor, cross-linking analysis. While in classical covalent binding studies a radioisotope-labeled ligand is employed, one can use 125 I-FRP as tracer in combination with unlabeled Wg (or other available soluble Wnt protein) and a cross-linking agent such as bis(sulfosuccinimidyl) suberate. Subsequent immunoprecipitation with antibody to Wg (or the appropriate epitope if a tagged Wnt molecule is involved), followed by SDS-PAGE and autoradiography will provide evidence of a direct FRP-Wg interaction.
[0106] Cellular binding assays can also be performed, using labeled FRP as tracer. While Wnt protein may be accessible at the cell surface, alternative models such as fusion proteins can be employed to anchor Wnt in the membrane and facilitate detection. Parkin, et al., Genes Dev. 7:2181-2193 (1993). While in such studies, the ligand-receptor relationship of Wg and FRP will be reversed; nonetheless, binding will occur and be suitable for Scatchard analysis. A quantitative measure of this condition can be obtained by assaying Wg-binding of the tracer in the ELISA disclosed in Example 8.
[0107] The present invention also provides a method for monitoring the course of a neoplastic condition in a subject. This method includes quantitatively determining in a first sample, from the subject, the presence of a Wnt molecule by detection method such as those commonly utilized in immunohistochemistry ( Current Protocols In Molecular Biology, Volume II, Unit 14, Frederick M. Ausubul et al. eds., 1995). The amount so determined is compared with an amount present in a second sample from the subject. Each sample is taken at a different point in time. A difference in the amounts determined is indicative of the course of the neoplastic condition.
[0108] As outlined above, FRP plays a role in neoplasia. Ectopic expression of Wnt-1 caused hyperplasia and adenocarcinoma in mouse mammary gland. (See e.g., Tsukamoto, et al., Cell 55:619-625 (1988)). Stabilization of beta-catenin—a hallmark of Wnt signaling—occurs with high frequency either as a consequence of mutation in the beta-catenin or APC genes in human colon cancer and melanoma. (See e.g., Korinek, et al.. Science 275:1784-1787 (1997)). The ability of FRP to inhibit Wnt signaling in the Xenopus axis duplication assay (Finch, et al., P.N.A.S. 94:6770-6775 (1997) and to decrease intracellular beta-catenin concentration in MCF-7 transfectants (Melkonyan, et al., P.N.A.S. 94:13636-13641 (1997)) suggests that FRP might function to suppress signaling in a pathway that can contribute to malignancy. FRP expression in MCF-7 cells apparently caused an increase in the number of cells undergoing apoptosis (Melkonyan, et al., P.N.A.S. 94:13636-13641 (1997)). Moreover, deletions or loss of heterozygosity have been described at the FRP chromosomal locus, 8p11.1-12, in association with kidney, breast, prostate, bladder and pancreas carcinoma and astrocytoma. See e.g., Mitelman, et al., Nature Genet 15: 417-474 (1997). Translocations at this locus were reported to occur in cases of myeloproliferative disease, T-ALL and T-PLL (Mitelman, et al., Nature Genet 15: 417-474 (1997)). Taken together, these observations raise the possibility that FRP may act as a tumor suppressor by inhibiting Wnt signaling and promoting apoptosis; loss of this function foster tumorigenesis.
[0109] One can perform a screen of FRP mRNA expression in a large sample of tumor cell lines. This can be accompanied by Southern blotting of restriction digests of genomic DNA from lines lacking FRP expression to look for gross changes in FRP gene structure. If no differences are seen relative to a normal control, more sensitive methods of detecting point mutations such as single strand conformation polymorphism (SSCP) can be used. Humphries, et al. Clin. Chem. 43:427-435 (1997). To facilitate this analysis, exon-intron boundaries of the FRP gene can be determined; and with this information, PCR primers can be designed to assist in the investigation of the gene structure of coding sequence. Any evidence of mutation can be confirmed by nucleotide sequence analysis. In addition to studying cell lines, one can screen paired tumor-bearing and tumor-free tissue specimens from individual patients. Gene targeting of FRP can also provide evidence of tumor suppressor function, if it resulted in mice that were prone to malignancy. Animals with this phenotype will serve as a useful model for the investigation of molecular events that culminate in neoplasia.
[0110] The invention also provides screening method for molecules that react with a Wnt or FRP molecules by a two-hybrid screen (Janouex-Lerosey I., Jollivet, F., Camonis, J.. Marche, P. N., and Goud, B., (1995) J. Biol. Chem. 270(24), 14801-14808) or by Western or Far Western techniques ( Current Protocols In Molecular Biology, Volume I, Unit 11, Frederick M. Ausubul et al. eds., 1995; Takayama, S., and Reed, J. C. (1997) Methods Mol. Biol. 69. 171-184). One method includes separately contacting each of a plurality of samples. Each sample contains a predefined number of cells. Further, each sample contains a predetermined amount of a different molecule to be tested.
[0111] Use of FRP Upstream Control Sequences For Evaluating Regulatory Processes
[0112] The genomic FRP control sequences of the present invention, whether positive, negative, or both, may be employed in numerous various combinations and organizations to assess the regulation of FRP. Moreover, in the context of multiple unit embodiments and/or in embodiments which incorporate both positive and negative control units, there is no requirement that such units be arranged in an adjacent head-to-head or head-to-tail construction in that the improved regulation capability of such multiple units is conferred virtually independent of the location of such multiple sequences with respect to each other. Moreover, there is no requirement that each unit include the same positive or negative element. All that is required is that such sequences be located upstream of and sufficiently proximal to a transcription initiation site.
[0113] To evaluate FRP regulatory elements in the context of heterologous genes, one simply obtains the structural gene and locates one or more of such control sequences upstream of a transcription initiation site. Additionally, as is known in the art, it is generally desirable to include TATA-box sequences upstream of and proximal to a transcription initiation site of the heterologous structural gene. Such sequences may be synthesized and inserted in the same manner as the novel control sequences. Alternatively, one may desire to simply employ the TATA sequences normally associated with the heterologous gene. In any event, TATA sequences are most desirably located between about 20 and 30 nucleotides upstream of transcription initiation.
[0114] Preferably the heterologous gene is a gene which encodes an enzyme which produces colorimetric or fluorometric change in the host cell which is detectable by in situ analysis and which is a quantitative or semi-quantitative function of transcriptional activation. Exemplary enzymes include esterases, phosphatases, proteases (tissue plasminogen activator or urokinase) and other enzymes capable of being detected by activity which generates a chromophore or fluorophore as will be known to those skilled in the art. A preferred example is E. coli β-galactosidase. This enzyme produces a color change upon cleavage of the indigogenic substrate indolyl-B-D-galactoside by cells bearing β-galactosidase (see, e.g., Goring et al., Science, 235:456-458 (1987) and Price et al., Proc. Natl. Acad. Sci. U.S.A., 84:156-160 (1987)). Thus, this enzyme facilitates automatic plate reader analysis of FRP control sequence mediated expression directly in microtiter wells containing transformants treated with candidate activators. Also, since the endogenous β-galactosidase activity in mammalian cells ordinarily is quite low, the analytic screening system using β-galactosidase is not hampered by host cell background.
[0115] Another class of reporter genes which confer detectable characteristics on a host cell are those which encode polypeptides, generally enzymes, which render their transformants resistant against toxins, e.g., the neo gene which protects host cells against toxic levels of the antibiotic G418: a gene encoding dihydrofolate reductase, which confers resistance to methotrexate, or the chloramphenicol acetyltransferase (CAT) gene (Osborne et al., Cell, 42:203-212 (1985)). Genes of this class are not preferred since the phenotype (resistance) does not provide a convenient or rapid quantitative output. Resistance to antibiotic or toxin requires days of culture to confirm, or complex assay procedures if other than a biological determination is to be made.
[0116] Use of FRP Nucleic Acids in the Generation of Transgenic Animals.
[0117] Nucleic acids which encode FRP or its modified forms can also be used to generate either transgenic animals or “knock out” animals which, in turn, are useful in the development and screening of therapeutically useful reagents. A transgenic animal (e.g., a mouse or rat) is an animal having cells that contain a transgene, which transgene was introduced into the animal or an ancestor of the animal at a prenatal, e.g., an embryonic stage. A transgene is a DNA which is integrated into the genome of a cell from which a transgenic animal develops. In one embodiment, cDNA encoding FRP can be used to clone genomic DNA encoding FRP in accordance with established techniques and the genomic or cDNA sequences can then be used to generate transgenic animals that contain cells which express DNA encoding FRP. Methods for generating transgenic animals, particularly animals such as mice or rats, have become conventional in the art and are described, for example. in U.S. Pat. Nos. 4,736,866 and 4,870,009. Typically, particular cells would be targeted for FRP transgene incorporation with inducible and tissue-specific control elements. Illustrative inducible and tissue specific control sequences include the mouse mamnimary tumor long terminal repeat (MMTV LTR) and the tetracycline elements respectively (see e.g. Hennighausen et al., J Cell Biochem December;59(4):463-72 (1995). Transgenic animals that include a copy of a transgene encoding FRP introduced into the germ line of the animal at an embryonic stage can be used to examine the effect of increased expression of DNA encoding FRP. Such animals can be used as tester animals for reagents thought to confer protection from, for example, pathological conditions associated with its overexpression. In accordance with this facet of the invention, an animal is treated with the reagent and a reduced incidence of the pathological condition, compared to untreated animals bearing the transgene would indicate a potential therapeutic intervention for the pathological condition.
[0118] Alternatively, non-human homologues of FRP can be used to construct a FRP “knock out” animal which has a defective or altered gene encoding FRP as a result of homologous recombination between the endogenous gene encoding FRP and altered genomic DNA encoding FRP introduced into an embryonic cell of the animal. For example, cDNA encoding FRP can be used to clone genomic DNA encoding FRP in accordance with established techniques. A portion of the genomic DNA encoding FRP can be deleted or replaced with another gene, such as a gene encoding a selectable marker which can be used to monitor integration. Typically, several kilobases of unaltered flanking DNA (both at the 5′ and 3′ ends) are included in the vector (see e.g., Thomas and Capecchi, Cell, 51:503 (1987) for a description of homologous recombination vectors). The vector is introduced into an embryonic stem cell line (e.g., by electroporation) and cells in which the introduced DNA has homologously recombined with the endogenous DNA are selected (see e.g., Li et al., Cell, 69:915 (1992)).
[0119] The selected cells are then injected into a blastocyst of an animal (e.g., a mouse or rat) to form aggregation chimeras [see e.g.. Bradley, in Teratocarcinomas and Embryonic Stem Cells: A Practical Approach, E. J. Robertson, ed. (IRL. Oxford, 1987), pp. 113-152]. A chimeric embryo can then be implanted into a suitable pseudopregnant female foster animal and the embryo brought to term to create a “knock out” animal. Progeny harboring the homologously recombined DNA in their germ cells can be identified by standard techniques and used to breed animals in which all cells of the animal contain the homologously recombined DNA. Knockout animals can be characterized for instance, for their ability to defend against certain pathological conditions and for their development of pathological conditions due to absence of the FRP polypeptide.
[0120] Advantages of the Invention.
[0121] FRP is a previously undescribed human gene product that is involved in regulating cellular growth and differentiation. This novel polypeptide antagonizes Wnt action. As a secreted antagonist which competes for a factor known to regulate cellular growth and development, FRP is a prototype for molecules that function as endogenous regulators of cytokine activity. As such, this novel protein has a variety of applications in the identification, characterization and regulation of activities associated with the Wnt family of cytokines.
EXAMPLES
[0122] Throughout this application, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the invention pertains. The following examples are presented to illustrate the present invention and to assist one of ordinary skill in making and using the same. The examples are not intended in any way to otherwise limit the scope of the invention.
Example 1
[0123] Purification and Physical Characterization of the FRP Protein.
[0124] Conditioned-medium collection, ultrafiltration, heparin-Sepharose affinity chromatography, and SDS/PAGE were performed as described (Rubin, J. S., Osada, H., Finch, P. W., Taylor, W. G., Rudikoff, S. & Aaronson, S. A. (1989) Proc Natl Acad Sci USA 86, 802-6). Hepatocyte growth factor/scatter factor (HGF/SF)-containing fractions were identified by immunoblotting. Occasionally heparin-Sepharose fractions were processed by reverse-phase C 4 HPLC (Rubin. J. S., Osada, H., Finch, P. W.. Taylor, W. G., Rudikoff, S. & Aaronson, S. A. (1989) Proc Natl Acad Sci USA 86, 802-6) to enhance purity of FRP. Gels were fixed and silver-stained using the reagents and protocol from Bio-Rad.
[0125] During the isolation of HGF/SF from human embryonic lung fibroblast culture fluid, a 36 kDa polypeptide which co-purified with HGF/SF following a variety of chromatography procedures was identified (Rubin, J. S., Chan, A. M., Bottaro, D. P., Burgess, W. H. Taylor, W. G., Cech, A. C., Hirshfield, D. W., Wong, J., Miki, T., Finch, P. W. & et al. (1991) Proc Natl Acad Sci USA 88, 415-9). Because the co-migration of this protein and HGF/SF suggested that it might regulate growth factor activity, a preparative scheme was devised to obtain sufficient quantities for study. This was accomplished by conservative pooling of fractions eluting from heparin-Sepharose resin with 1.0 M NaCl, once it became evident that a portion of the 36 kDa protein emerged after the HGF/SF-containing fractions. Protein obtained in this manner was sufficiently pure and abundant for structural and limited functional analysis (FIG. 1A).
[0126] Microsequencing.
[0127] Approximately 30 μg of protein was loaded onto an Applied Biosystems gas-phase protein sequenator. Forty rounds of Edman degradation were carried out, and phenylthiohydantoin amino acid derivatives were identified with an automated on-line HPLC column (model 120A, Applied Biosystems).
[0128] [0128]FIG. 1 provides illustrations of these protocols and results. FIG. 1 consists of a series of panels. Panel (A) shows an SDS/PAGE analysis of heparin-Sepharose purified FRP. Approximately 200 ng of protein was resolved in a 4-20% polyacrylamide minigel (Novex) under reducing (+) or non-reducing (−) conditions, and subsequently stained with silver. The position of molecular mass markers is indicated at the right.
Example 2
[0129] Molecular Cloning and Characterization of FRP Nucleic Acid Sequences.
[0130] Four pools of 26-base degenerate oligonucleotides were synthesized on the basis of either of two segments of amino acid sequence determined by microsequencing of purified FRP. Two pools corresponding to the sequence NVGYKKMVL contained all possible codon combinations except for the substitution of inosine residues in the third positions of the codons for the first Val and Gly; one subset terminated with bases CT and the other with TT. Two additional pools, corresponding to the sequence FYTKPPQXV, contained all possible codon combinations except for the substitution of inosine residues in the third positions of the codons for both Pro residues; one subset contained four codon options for Ser in the X position, while the other had the remaining two. Oligonucleotide pools were labeled and used to screen an oligo (dT)-primed M426 cDNA library as previously described (Finch, P. W.. Rubin, J. S.. Miki, T., Ron, D. & Aaronson, S. A. (1989) Science 245, 752 5).
[0131] Microsequencing of the purified 36 kDa protein yielded two amino-terminal sequences, one beginning three residues downstream from the other. Positive identifications were made in 37 of the first 40 cycles of Edman degradation, as follows:
[0132] FQSDIGPYQSGRFYTKPPQXVDIPADLRLXXNVGYKKMVL (X denotes inability to make an amino acid assignment). Degenerate oligonucleotides corresponding either to sequence FYTKPPQXV or NVGYKKMVL were used to probe a M426 cDNA library. An initial screening of 10 6 plaques yielded approximately 350 clones recognized by probes derived from both peptide segments. Restriction digestion of several plaque-purified phage DNAs revealed two classes of inserts. Selected cDNA inserts were analyzed by restriction endonuclease digestion. The nucleotide sequence of the FRP cDNAs was determined by the dideoxy chain-termination method. To search for homology between FRP and any known protein, we analyzed the GenBank, PDB, SwissProt and PIR protein sequence data bases. Alignments were generated with the program PileUp from the Wisconsin Package Version 8 (Genetics Computer Group; Madison Wis.). Mapping (FIG. 1B) and sequence analysis (FIG. 1C) of a representative from each class, designated HS1 and HS8, demonstrated that they were overlapping cDNAs. HS1 was ˜2 kb in length and contained a 942-bp open reading frame; HS8 encoded a portion of the 942-bp open reading frame as well as approximately 0.3 kb of cDNA extending upstream of the ATG start codon. The putative start codon, located at position 303 in the HS1 sequence, was flanked by sequence that closely matched the proposed GCC(G/A)CCATGG consensus sequence for optimal initiation by eukaryotic ribosomes (Kozak, M. (1987) Nucleic Acids Res 15, 8125-48). An upstream in-frame stop codon was not present.
[0133] As expected for a secreted protein, a hydrophobic 26-amino acid segment at the NH2-terminus likely functions as a signal peptide. The experimentally determined protein sequence begins 11 residues downstream from the presumptive signal sequence, suggesting additional processing or incidental proteolysis. There was complete agreement between the predicted and observed amino acid sequences; the three undefined residues in the latter corresponded to Cys57, Cys67 and His68, residues which typically are undetectable or have low yields following Edman degradation. Two overlapping sequences in the COOH terminal region fulfill the criteria for a consensus binding site to a hyaluronic acid (Yang, B., Yang, B. L., Savani, R. C. & Turley. E. A. (1994) Embo J 13, 286-96) (FIG. 1C). Two potential asparagine-linked glycosylation sites are also present. A consensus polyadenylation signal was not identified in the cDNA sequence, raising the possibility that the CDNA clones from this oligo-dT primed library resulted from internal priming at an adenine-rich region.
[0134] Once a FRP cDNA was isolated, FRP genomic sequences were readily identified by methods that are well known in the art. Briefly, a human genomic DNA library (Stratagene) was screened by Southern blotting with two different human FRP cDNA probes: pF2 insert was used to identify genomic fragments containing any of the coding sequence; SalI-BstXI fragment (bp 417-781, according to numbering scheme for pF2) was used to identify genomic fragment(s) containing sequence encoding the cysteine-rich domain (CRD). Phage containing DNA that hybridized with FRP probes were plaque-purified, and portions of the genomic DNA inserts were then isolated and sequenced. A portion of the genomic sequence including the 5′ flanking region is illustrated in FIG. 11.
[0135] Relationship to the FZ Protein Family.
[0136] Search of several protein databases revealed significant homology of a portion of the predicted amino acid sequence to a specific region conserved among members of the FZ family (FIG. 2). The observed homology is confined to the extracellular CRD of FZ, a region consisting of ˜110 amino acid residues that includes 10 cysteines and a small number of other invariant residues. This domain has special importance because it is a putative binding site for Wnt ligands (Bhanot, P., Brink, M., Samos, C. H., Hsieh, J. C., Wang, Y., Macke, J. P., Andrew, D., Nathans, J. & Nusse, R. (1996) Nature 382, 225-30). The FRP CRD is 30-42% identical to the CRD of the other FZ proteins.
[0137] In addition to the plasma membrane-anchored FZ proteins and FRP, three other molecules have been described which also possess a FZ CRD motif. An alternatively spliced isoform of mouse collagen XVIII was the first such protein to be reported (Rehn, M. & Pihlajaniemi, T. (1995) J Biol Chem 270, 4705-11). The two other molecules, mouse SDF5 (Shirozu, M., Tada, H., Tashiro, K., Nakamura. T., Lopez, N. D., Nazarea, M., Hamada, T., Sato, T., Nakano, T. & Honjo, T. (1996) Genomics 37, 273-280) and human FRZB (Hoang, B., Moos, M., Jr., Vukicevic, S. & Luyten, F. P. (1996) J Biol Chem 271, 26131-26137), resemble FRP in that each consists of ˜300 amino acid residues, including a signal peptide, CRD near its NH2-terminus and a hydrophilic COOH-terminal moiety. FRP and SDF5 have 58% identities in their CRDs, while FRP and FRZB are only 32% identical in this region. Elsewhere, these molecules are only 15-20% identical. Thus, FRP, SDF5 and FRZB may constitute a subfamily of small, FZ-related proteins that lack the seven transmembrane motif responsible for anchoring FZ proteins to the plasma membrane and are presumably secreted.
[0138] [0138]FIGS. 1 and 2 and 8 provide illustrations of these protocols and results. FIG. 1 consists of a series of panels. Panel (B) shows a representation of human FRP cDNA clones. Overlapping clones HS1 and HS8 are shown above a diagram of the complete coding sequence and the adjacent 5′ and 3′ untranslated regions. The coding region is boxed; the open portion corresponds to the signal sequence. Untranslated regions are represented by a line. Selected restriction sites are indicated. Panel (C) shows the predicted FRP amino acid sequence (standard single-letter code). The peptide sequence obtained from the purified protein is underlined. Double-underlined sequences were used to generate oligonucleotide probes for screening of the M426 cDNA library. The putative signal sequence is italicized. The large shaded region is the cysteine-rich domain homologous to CRD's in members of the FZ family. The small shaded region is the lysine-rich segment that fulfills the criteria for a consensus hyaluronic acid-binding sequence. The dashed underlining denotes two potential asparagine-linked glycosylation sites.
[0139] [0139]FIG. 8 shows the nucleic acid sequence which encodes a FRP polypeptide. At ˜nucleotide 340 we denote with an asterisk a site in the molecule where we observe an insert of the sequence “CAG” in some constructs. This would result in an insert of a single amino acid residue (alanine) in the putative signal peptide sequence without altering any of the remaining amino acid sequence. This may result from alternative splicing or possibly a sequencing artifact.
[0140] [0140]FIG. 2 provides comparisons of the CRDs of FRP and other members of the FZ family. Solid black shading highlights identities present in human FRP and any other FZ family member. The consensus sequence indicates residues present in at least eight of the sixteen FZ or FZ-related proteins. Double asterisks denote the ten invariant cysteine residues; single asterisks indicate other invariant residues. hFRP, human FZ-related protein; hFZ (Zhao, Z., Lee, C., Baldini, A. & Caskey, C. T. (1995) Genomics 27, 370-3); hFZ5 (Wang, Y., Macke, J. P., Abella, B. S., Andreasson, K., Worley, P. Gilbert, D. J., Copeland, N. G., Jenkins, N. A. & Nathans, J. (1996) J Biol Chem 271, 4468-76); mFZ3-mFZ8 (Wang, Y., Macke, J. P. Abella, B. S., Andreasson, K., Worley, P., Gilbert, D. J., Copeland, N. G., Jenkins, N. A. & Nathans, J. (1996) J Biol Chem 271, 4468-76); rFZ1 and rFZ2 (Chan, S. D., Karpf, D. B. Fowlkes, M. E., Hooks, M., Bradley M. S., Vuoung, V., Bambino, T., Liu, M. Y., Arnaud, C. D., Strewler, G. J. & et al. (1992) J Biol Chem 267, 25202-7); dFZ (Vinson, C. R., Conover, S. & Adler, P. N. (1989) Nature 338, 263-4); dFZ2 (Bhanot, P., Brink, M., Samos, C. H., Hsieh, J. C., Wang, Y., Macke, J. P.. Andrew, D., Nathans, J. & Nusse, R. (1996) Nature 382, 225-30); cFZ (Wang, Y., Macke, J. P., Abella, B. S., Andreasson, K., Worley, P., Gilbert, D. J., Copeland, N. G., Jenkins, N. A. & Nathans, J. (1996) J Biol Chem 271, 4468-76); mCOL, mouse collagen XVIII (Rehn, M. & Pihlajaniemi, T. (1995) J Biol Chem 270, 4705-11); hFRZB (Hoang, B., Moos, M., Jr., Vukicevic, S. & Luyten, F. P. (1996) J Biol Chem 271, 26131 7); mSDF5 (Shirozu, M., Tada, H., Tashiro, K., Nakamura, T., Lopez, N. D., Nazarea, M., Hamada, T., Sato, T., Nakano, T. & Honjo, T. (1996) Genomics 37, 273-280).
Example 3
[0141] Expression of the FRP Gene.
[0142] Northern and Southern Blot Analysis.
[0143] RNA from cell lines was isolated, transferred to nitrocellulose filters, and hybridized with labeled probes as previously described (Finch, P. W., Rubin, J. S., Miki, T., Ron, D. & Aaronson, S. A. (1989) Science 245, 752 5). Northern blots containing approximately 2 μg of poly A+RNA isolated from a variety of different organs were purchased from Clontech (Palo Alto, Calif.). Labeled probes were hybridized in Express Hyb hybridization solution (Clontech) according to the manufacturer's protocol. The FRP NotI-SmaI eDNA fragment and human β-actin cDNA probe provided by Clontech were 32 P-labeled with random hexamers and used at a concentration of 1 -2×10 6 cpm/ml (specific activity >8×10 8 cpM/μg DNA).
[0144] Southern blotting was performed as previously described (Kelley, M. J., Pech, M., Seuanez, H. N., Rubin, J. S.. O'Brien, S. J. & Aaronson, S. A. (1992) Proc Natl Acad Sci US A 89, 9287-91), except for variation in formamide concentration during hybridization, as noted in the text. FRP cDNA probes were 32 P-labeled with the nick-translation kit from Amersham.
[0145] FRP Gene is Expressed in Multiple Organs and Cell Types.
[0146] Using the 1081-bp NotI-SmaI fragment of HS1 (FIG. 1B) as probe, a single 4.4 kb transcript was detected in polyA+RNA from several human organs (FIG. 3). In adult tissues, the highest level of expression was observed in heart, followed by kidney, ovary, prostate, testis, small intestine and colon. Lower levels were seen in placenta, spleen and brain, while transcript was barely detectable in skeletal muscle and pancreas. No hybridization signal was evident in mRNA from lung, liver, thymus or peripheral blood leukocytes. In poly A+RNA from a small sample of human fetal organs, the 4.4 kb transcript was highly represented in kidney, at moderate levels in brain, barely detectable in lung, and undetectable in liver.
[0147] Northern analysis of total RNA from various human cell lines demonstrated the 4.4 kb transcript and, occasionally, additional faint bands not further analyzed (FIG. 3, extreme right panel). While the transcript was detected in RNA from embryonic lung (M426 and WI-38) and neonatal foreskin (AB1523) fibroblasts, it was not observed in a sample of adult dermal fibroblasts (501T). In addition to fibroblasts, the transcript was seen in RNA from primary keratinocytes, indicating that expression was not limited to cells of mesenchymal origin. Considering that the cumulative size of the initial overlapping FRP cDNAs was only 2.8 kb, detection of a 4.4 kb transcript reinforced the suggestion that the cDNAs were generated by internal priming at adenine-rich regions. An illustration of the sequence of this larger transcript is provided in FIG. 8.
[0148] Developmental Expression of FRP
[0149] Northern blot analysis of samples from human organs indicates that the FRP transcript was expressed at many sites and the level of expression varied in embryonic and adult tissues. Finch, et al., P.N.A.S. 94: 6770-6775 (1997). To assess its pattern of expression and potential role in development, we investigated the distribution of FRP transcript in mouse embryos by in situ hybridization analysis. A 144-bp mouse FRP cDNA fragment was generated by RT-PCR, using total RNA from NIH/3T3 fibroblasts as template. After subcloning into pGEM3Zf(−), 35 S-labeled sense and antisense riboprobes were prepared for hybridization. These experiments suggest that FRP transcript is present in embryos from 8.5 days to birth, with highest overall levels of expression observed at 12.5-14.5 days. At this peak period, expression was documented in discrete portions of the central nervous system, gastrointestinal tract, genitourinary system, lining of the abdominal cavity, heart and developing vertebrae. Transcript was present either in mesenchymal or epithelial cells, depending on the location. The transient aspect of FRP spatiotemporal distribution reinforced the idea that its expression is regulated during development. Like the Wnt proteins, FRP participates in processes that govern embryonic development.
[0150] Detection of FRP in Other Species.
[0151] To determine whether the FRP gene was present in other species, genomic DNAs from various sources were fully digested with EcoRI and hybridized with an Ncol-SmaI cDNA fragment (FIG. 1B) under varying conditions of stringency (FIG. 5). Multiple bands were observed under highly stringent conditions (50% formamide) in DNA from human rhesus monkey, mouse and chicken. With moderate stringency (35% formamide), no additional fragments were seen in the DNA from these species but fragments were detected in Xenopus DNA. No hybridization signal was observed with DNA from Drosophila or yeast ( S. cervisiae ) in these experiments. At low stringency (20% formamide), the background was too high to detect specific signals. These results strongly suggested that the FRP gene is highly conserved among vertebrates. Although these experiments did not detect an FRP homolog in the invertebrates, the existence of such homologs was not rigorously excluded, due to the limitations of the method.
[0152] Southern blotting performed either with the NotI-NcoI cDNA fragment (FIG. 1B) or with synthetic oligonucleotide probes corresponding to different portions of the FRP coding sequence, hybridized to subsets of genomic fragments detected with the NcoI-SmaI probe. This finding and the lack of additional bands detected only under relaxed conditions (FIG. 5) indicated that highly related FRP-like sequences are not present in the human genome. Thus, the multiple genomic fragments hybridizing to the FRP cDNA in Southern blots are likely to reflect the presence of several exons in the hFRP gene.
[0153] [0153]FIGS. 3 and 5 provide an illustration of these protocols and results. FIG. 3 shows FRP mRNA expression in normal human adult and embryonic tissues, and in cultured cells. Blots containing approximately 2 μg of poly A+RNA from each of the indicated tissues or 10 μg of total RNA from different human cell lines were probed with radiolabeled FRP and β-actin cDNA fragments, as described in the Methods. The position of DNA size markers, expressed in kb, is indicated at the left of the tissue blots; the position of 28S and 18S ribosomal RNA is shown at the left of the cell blot.
[0154] [0154]FIG. 5 shows a southern blot analysis of FRP genomic sequences in different species. After fractionation by agarose gel electrophoresis and transfer to filters, Eco-RI-digested genomic DNAs were hybridized in the presence of either 50% or 35% formamide. Specimens were from the following species: λ, lambda phage; H, human; M k , rhesus monkey; M o , mouse; C, chicken; X, Xenopus laevis; D, Drosophila melanogaster; Y, yeast ( S. cerevisiae ).
Example 4
[0155] Chromosomal Localization of FRP.
[0156] A 4.1 kb FRP genomic fragment obtained from a human fibroblast genomic DNA library (Stratagene) was labeled with biotin or digoxigenin and used as a probe for in situ hybridization to locate the FRP gene in chromosomal preparations of methotrexate-synchronized normal peripheral human lymphocyte cultures. The conditions for hybridization, detection of fluorescent signal, digital-image acquisition, processing and analvsis were as previously described (Zimonjic, D. B., Popescu, N. C., Matsui, T., Ito, M. & Chihara, K. (1994) Cytogenet Cell Genet 65, 184-5). The identity of the chromosomes with specific signal was confirmed by rehybridization using a chromosome 8-specific probe, and the signal was localized on G-banded chromosomes.
[0157] Using a fluorescent-labeled 4.1 kb genomic fragment containing a portion of the FRP coding sequence, in situ hybridization revealed a single locus at chromosome 8p11.1-12 (FIG. 4). This site may be near the putative locus of the hFZ3 gene, based on homology with the location of mFz3 in the mouse genome (Wang, Y., Macke, J. P., Abella, B. S., Andreasson, K., Worley, P., Gilbert, D. J., Copeland, N. G., Jenkins, N. A. & Nathans, J. (1996) J Biol Chem 271, 4468-76). Radiation hybrid analysis yielded results consistent with the fluorescent in situ hybridization analysis. Significantly, the chromosomal locus of the FRP gene is compatible with that of a tumor suppressor gene associated prostate, colon, and non small cell lung carcinoma. Information on FRP genomic structure and its relationship to defects in these malignancies is a material avenue of research in this field.
[0158] [0158]FIG. 4 provides an illustration of these protocols and results. FIG. 4 shows the chromosomal localization of the FRP gene by fluorescent in situ hybridization. To localize the FRP gene, one hundred sets of metaphase chromosomes were analyzed. In eighty metaphases, a double fluorescent signal was observed with the FRP genomic problem in 8p11.2-12 on both chromosome homologs (left panel). The identity of the chromosomes was confirmed by hybridization with a probe specific for chromosomes 8 (right panel).
Example 5
[0159] Biosynthetic Studies of FRP.
[0160] For biosynthetic studies, M426 cells grown in T-25 flasks were incubated for 30 min in methionine-free DMEM in the presence or absence of 50 μg/ml heparin (bovine lung, Sigma; when present, heparin was included in all subsequent media), which was subsequently replaced with medium containing 35 S-methionine (1 mCi/5 ml per dish). After 30 min., the radioactive medium was removed, and monolayers washed with medium containing unlabeled methionine, then incubated for varying intervals in fresh nonradioactive medium. At the specified times, the conditioned media and cell lysates were collected and processed as previously described (Rubin, J. S., Chan, A. M., Bottaro, D. P., Burgess, W. H. Taylor, W. G., Cech, A. C., Hirshfield, D. W., Wong, J., Miki, T., Finch, P. W. & et al. (1991) Proc Natl Acad Sci USA 88, 415-9). Immunoprecipitations were performed with a rabbit polyclonal antiserum (100 μg/ml) raised against a synthetic peptide corresponding to FRP amino acid residues 41-54, in the presence or absence of competing peptide (50 μg/ml). Immune complexes adsorbed to GammaBind (Pharmacia) were pelleted by centrifugation and washed; labeled proteins were resolved by SDS/PAGE and detected by autoradiography.
[0161] [0161]FIG. 6 provides an illustration of these results. FIG. 6 shows the biosynthesis of FRP in M426 cells. A pulse-chase experiment was performed with metabolically labeled cells incubated either in the absence or presence of heparin. Proteins were immunoprecipitated from cell lysates (C.L.) or conditioned medium (C.M.) with FRP peptide antiserum in the absence or presence of competing peptide, and resolved in a 10% polyacrylamide SDS gel. Cells and media were harvested 1, 4 or 20 hours after a 30 min labeling period. Lanes 1-24 are labeled at the bottom. The protein band corresponding to FRP is indicated by an arrow. The position of molecular mass markers is shown at the left.
[0162] FRP is Secreted, but Primarily Cell-Associated in the Absence of Exogenous Heparin.
[0163] To study the synthesis and processing of FRP protein, a pulse-chase experiment was performed with 35 S-methionine labeled M426 cells either in the absence or presence of added heparin. As shown in FIG. 6, a 36 kDa protein band was specifically immunoprecipitated with antiserum raised against a synthetic peptide corresponding to a portion of the FRP NH2-terminal sequence. In the absence of soluble heparin, after either 1 hour (lanes 1 and 5) or 4 hours (lanes 9 and 13) FRP was much more abundant in the cell lysate than in the conditioned medium. However, after 20 hours, the amount of FRP protein in the medium (lane 21) was comparable to that which remained cell-associated (lane 17). At this last time point, the combined band intensity in the two compartments had decreased relative to that observed earlier, suggesting significant protein turnover during the experiment. Moreover after 20 hr the FRP-specific signal appeared as a doublet, providing additional evidence of proteolysis. In the presence of soluble heparin (50 μg/ml), most of the FRP was detected in the medium at all three time points (compare lanes 3 and 7, 11 and 15, 19 and 23). Heparin also appeared to stabilize FRP as the band intensity was stronger when heparin was present, and there was no evidence of partial proteolysis. Interestingly others have shown that heparin can release Wnt-1 from the cell surface in a similar manner (Papkoff, J. & Schryver, B. (1990) Mol Cell Biol 10, 2723-30: Bradley, R. S. & Brown, A. M. (1990) Embo J 9, 1569-75; Reichsman, F., Smith, L. & Cumberledge, S. (1996) J Cell Biol 135, 819-27). Taken together, our results demonstrate that FRP is secreted, although it tends to remain cell-associated and relatively susceptible to degradation unless released into the medium by soluble heparin.
[0164] FRP Binds to Hyaluronic Acid.
[0165] As shown by the amino acid sequence in FIG. 1C, FRP contains a lysine-rich segment that fulfills the criteria for a consensus hyaluronic acid-binding sequence (Yang. B., Yang, B. L., Savani, R. C. & Turley, E. A. (1994) Embo J 13, 286-96). FIG. 9 shows the binding of FRP to biotinylated hyaluronic acid in a transblot assay under either nonreducing (−) or reducing (+) conditions (Yang, B, Zhang, L., and Turley, E. A. (1993) J. Bio. Chem. 268, 8617-8623; Hardwick, C., Hoare, K., Owens, R. Hohn, H. P., Hook, M., D., Cripps and Turley, E. A. (1992) J. Cell Biol. 117, 1343-1350). Further, FIG. 10 shows the competition of BHA binding to FRP by various proteoglycans, C.S. is chondroitin sulfate, H.A. is hyaluronic acid, H.A. oligo is hyaluronic acid oligosaccaride. The Ab control consists of a western blot of FRP with rabbit polyclonal antiserum raised against FRP synthetic peptide.
[0166] [0166]FIGS. 9 and 10 provide an illustration of these results. FIG. 9 shows the binding of FRP to biotinylated hyaluronic acid in a transblot assay under either nonreducing (−) or reducing (=) conditions. FIG. 10 shows the competition of BHA binding to FRP by various proteoglycans, C.S. is chondroitin sulfate, H.A. is hyaluronic acid, H.A. oligo is hyaluronic acid oligosaccaride. The Ab control consists of a western blot of FRP with rabbit polyclonal antiserum raised against FRP synthetic peptide.
Example 6
[0167] Modulation of Xenopus Development By FRP.
[0168] Wnt-1, wg, Xwnt-3a and Xwnt-8 plasmids were used as described (McMahon, A. P. & Moon, R. T. (1989) Development 107 Suppl, 161-7; Chakrabarti, A., Matthews, G., Colman, A. & Dale, L. (1992) Development 115, 355-69; Wolda, S. L., Moody, C. J. & Moon, R. T. (1993) Dev Biol 155, 46-57; Smith, W. C. & Harland, R. M. (1991) Cell 67, 753-65). The FRP NaeI-SalI CDNA fragment, which includes the full coding sequence, was subcloned into the StuI and XhoI sites of pCS2+(Turner. D. L. & Weintraub, H. (1994) Genes Dev 8, 1434-47). All mRNAs for injection were synthesized as capped transcripts in vitro with SP6 RNA polymerase (Ambion Megascript Kit). Embryo preparation and staging were performed as described (He, X., Saint-Jeannet, J. P., Woodgett, J. R., Varmus, H. E. & Dawid, I. B. (1995) Nature 374, 617-22). Transcripts were injected into the two blastomeres near the equatorial midline region at the 4-cell stage.
[0169] FRP Antagonizes Wnt Action in Xenopus Embryo Assay.
[0170] Because FRP possesses a potential binding site for Wnt molecules and appears to partition among cellular compartments like Wnt-1, it seemed possible that FRP might modulate the signaling activity of Wnt proteins. We envisioned two alternatives: FRP might antagonize Wnt function by binding the protein and blocking access to its cell surface signaling receptor, or FRP might enhance Wnt activity by facilitating the presentation of ligand to the FZ receptors, analogous to the action of soluble interleukin 6 receptors (Kishimoto, T., Taga, T. & Akira, S. (1994) Cell 76, 253-62).
[0171] To test these possibilities, we examined the effect of FRP on Wnt-dependent dorsal axis duplication during Xenopus embryogenesis. Previous studies have demonstrated that microinjection of mRNA encoding certain Wnt molecules, such as mouse Wnt-1, Wg. XWnt-8 or XWnt-3a, into early Xenopus embryos can induce the formation of an ectopic Spemann organizer and, subsequently, duplication of the dorsal axis (McMahon, A. P. & Moon, R. T. (1989) Development 107 Suppl, 161-7; Chakrabarti, A., Matthews, G., Colman, A. & Dale, L. (1992) Development 115, 355-69; Wolda, S. L., Moody, C. J. & Moon, R. T. (1993) Dev Biol 155, 46-57; Smith, W. C. & Harland, R. M. (1991) Cell 67, 753-65; Moon, R. T., Christian, J. L., Campbell, R. M., McGrew, L., DeMarais, A., Torres, M., Lai, C. J., Olson, D. J. & Kelly, G. M. (1993) Dev Suppl, 85-94; Sokol, S., Christian, J. L., Moon, R. T. & Melton, D. A. (1991) Cell 67, 741-52). In addition, it has been reported that FRZB is a secreted antagonist of Wnt signaling expressed in the Spemann organizer (Leyns, L., Bouwmeester, T., Kim, S. H., Piccolo, S. & De Robertis, E. M. (1997) Cell 88, 747-756, Wang, S., Krinks, M., Lin, K., Luyten, F. P. & Moos, M. J. (1997) Cell 88. 757-766).
[0172] [0172]FIG. 7 provides an illustration of these results. FIG. 7 shows the dorsal axis duplication in Xenopus embryos in response to varying combinations of Wnt and FRP transcripts. The total number of embryos injected in two to four independent experiments is indicated by the value of n; each bar represents the percentage of axis duplication; the solid portion within each bar represents the percentage of extensive duplication, which is defined by the presence of the cement gland and at least one eye in the duplicated axis. The amount of mRNA injected per embryo is shown below the bars.
[0173] As illustrated in FIG. 7, injection of suboptimal doses of Wnt-1, Wg, or XWnt-8 mRNA into embryos induced partial or complete duplication in at least 75% of the animals. Suboptimal doses were used to enable the detection of enhancement of the axis duplication phenotype, if the role of FRP was to facilitate Wnt signaling. However, when similar quantities of FRP and Wnt RNA were coinjected, the incidence and extent of axial duplication were significantly reduced (FIG. 7). The effect was dose-dependent, as the number of animals with an abnormal phenotype was even lower when the relative amount of FRP RNA was increased five- to ten-fold. Injection of FRP RNA alone at a higher dose (100 pg) into the dorsal side of the embryo did not affect the endogenous dorsal axis formation.
[0174] Surprisingly, FRP was much less effective in antagonizing XWnt-3a, suggesting a degree of specificity regarding interactions with different members of the Wnt family. The Wnt signaling pathway is thought to proceed through suppression of the activity of glycogen synthase kinase-3, a cytoplasmic serine-threonine kinase (Miller, J. R. & Moon, R. T. (1996) Genes Dev 10, 2527-39). Axis duplication induced by a dominant-negative, kinase-inactive mutant of glycogen synthase kinase-3β (He. X.. Saint-Jeannet, J. P., Woodgett. J. R., Varmus, H. E. & Dawid, I. B. (1995) Nature 374, 617-22; Dominguez, I., Itoh, K. & Sokol, S. Y. (1995) Proc Natl Acad Sci USA 92, 8498-502; Pierce, S. B. & Kimelman, D. (1995) Development 121, 755-65) was not affected by FRP, consistent with the assumption that FRP directly interferes with Wnt signaling at the cell surface not by indirectly interfering with a late step in the Wnt signaling pathway.
Example 7
[0175] Expression and Purification of Recombinant FRP.
[0176] As disclosed in detail below, recombinant FRP has been produced in a stable mammalian expression system involving Madin-Darby canine kidney (MDCK) cells. One of the advantages of eukaryotic expression is the reliability of disulfide bond formation and associated protein folding, which are likely to be important in the synthesis of the secreted cysteine-rich FRP protein. In contrast, preliminary experiments with prokaryotic expression yielded protein that appeared to be heterogeneous with respect to the folding of disulfide bonds. MDCK cells were transfected by standard calcium phosphate precipitation methodology with a pcDNA vector (Invitrogen) containing the FRP coding sequence. Following G418 selection of transfected cells, immunoblot analysis of conditioned medium from a mass culture revealed the presence of recombinant FRP-crossreactive protein. The amount of FRP in the medium from FRP-transfected MDCK cells appeared to be far greater than quantities produced by cell lines naturally expressing FRP.
[0177] As discussed in detail below, the MDCK/FRP culture was expanded into T-175 flasks and a series of pilot experiments conducted to develop a scheme for the purification of recombinant protein. Once the cells reached confluence, serum-containing growth medium was removed, the monolayer was washed twice with phosphate-buffered saline, and then serum-free medium was added. After 72 hours, the culture fluid was harvested and serum-containing medium was added to the flasks. Subsequently, the monolayer was again washed and serum-free medium introduced for another 72 hour period of conditioning. This process was repeated four or five times with the same monolayer cultures. The conditioned medium was promptly concentrated by ultrafiltration at 4° C. in a stirred chamber with a 10-kDa molecular mass cutoff (Amicon). Immunoblot analysis confirmed that FRP protein was present in the retentate, and its concentration was markedly increased compared to that of the starting material. The retentate was fractionated by heparin-TSK high performance liquid chromatography (HPLC).
[0178] [0178]FIG. 12 provides an illustration of these results. FIG. 12 shows recombinant FRP. (A) Preparation of FRP protein. The FRP coding sequence was subcloned into pcDNA3.1(+) and transfected into MDCK cells by standard calcium phosphate precipitation methodology. Following selection, transfected cells were grown to confluence and switched to serum-free medium. After 72 hours, conditioned medium was collected, concentrated by ultrafiltration and fractionated by heparin-TSK HPLC. At least 90% of the protein did not bind to resin equilibrated in 0.05M phosphate/0.15M NaCl/pH 7.4. After eluting the less tightly bound protein with 0.5M NaCl (data not shown), a modified linear gradient of increasing [NaCl] was used to recover the remaining protein. (B) Immunoblotting with FRP peptide antiserum. Ten μl aliquots of selected 1 min fractions from heparin-TSK chromatography (indicated by bar in panel A) were resolved by 12% SDS-PAGE, transferred to Immobilon filters, blotted with FRP amino-terminal peptide antiserum (Finch, et al., P.N.A.S. 94: 6770-6775 (1997)) and analyzed by chemiluminescence. Position of molecular mass markers (kDa) is shown at left. (C) Silver-staining of FRP-containing fractions from heparin-TSK chromatography. Five μl aliquots of indicated fractions were subjected to 12% SDS-PAGE and silver-stained (BioRad kit). Position of molecular mass markers (kDa) is shown at left.
[0179] Most protein did not bind to the resin, which had been equilibrated at neutral pH in isotonic buffer. Following a stepwise increase of NaCl concentration to 0.5M, the remaining protein was eluted with a modified linear gradient of increasing [NaCl] (FIG. 12A). FRP was detected by western blotting of aliquots from the major, overlapping protein peaks which eluted with 1.1-1.4M NaCl (FIG. 12B). Silver-staining of proteins resolved by SDS-PAGE demonstrated that the peak fractions only contained bands corresponding in size to immunoreactive FRP (FIG. 12C). Based on optical density, the estimated yield of FRP protein was 0.5-1.0 mg from two liters of conditioned medium (˜50-100 times more than the original, naturally occurring source).
[0180] Detailed Recombinant FRP Recombinant Expression Protocols.
[0181] Vectors and constructs included pcDNA3.1(+) with both the full-length human FRP coding sequence as well as site directed mutants of full-length FRP, in which substitutions (Asn to Gln) were made at either or both of the Asn-linked glycosylation sites. Additional vectors included pcDNA3.1(−)/Myc-His C designed to link Myc and His tags to the carboxy-terminus of recombinant protein of the full-length human FRP coding sequence as well as three truncated FRP derivatives, each lacking a varying amount of the carboxy-terminal portion of the full-length protein; sequences span: 1-171, 1-221, and 1-242.
[0182] Constructs were transfected into MDCK cells by standard calcium phosphate methodology, and cultures were subjected to selection with antibiotic (G418, 0.5 mg/ml). Transfected mass culture was expanded, ultimately grown in the absence of G418 (growth medium is DMEM plus 10% fetal bovine serum). Clonal lines were isolated from the mass culture of FRP/MDCK transfectants and screened for elevated FRP expression by immunoblot analysis of culture fluid.
[0183] To generate conditioned medium, cells were grown to confluence in T175 flasks (alternatives known in the art also should be suitable, such as cell factories or microcarriers in bioreactors). Medium in these experiments was switched from DMEM plus 10% fetal bovine serum to serum-free DMEM. After 2 or 3 days, conditioned medium was harvested and optionally another round of serum-free DMEM was added, to be harvested, typically after another 3 days. As many as 10 collections could be made from a single monolayer. In some instances, cells were cycled from serum-free to serum containing medium, before switching back to serum-free medium for subsequent collection of conditioned medium
[0184] Medium was filtered through a 0.45 micron membrane prior to concentration by ultrafiltration. Optionally medium was clarified by centrifugation before filtration. For ultrafiltration, conditioned medium was concentrated in a stainless steel, Amicon model 2000 stirred cell with a YM-10 membrane (10 kD molecular mass cutoff) at 4° C. Typically volumes of 1-2 liters were reduced to 45-90 ml. Concentrates were snap-frozen and stored in freezer.
[0185] Purification of FRP.
[0186] As discussed above, wild type FRP was purified with heparin affinity chromatography. Details of chromatography varied, from linear NaCl gradient with heparin-HPLC column to stepwise NaCl elution with Pharmacia Hi-Trap heparin column. FRP elutes with approximately 1.0 M NaCl.
[0187] FRP derivatives containing a Myc-His tag were purified with nickel resin (such as a Pharmacia Hi-Trap His column), typically being eluted with 50 or 100 mM imidazole solution. FRP-containing fractions were identified by immunoblotting and silver stain analysis following SDS-PAGE (12% polyacrylamide). Fractions were snap-frozen and stored in freezer.
Example 8
[0188] FRP and FRP Binding Partner Interaction Assays.
[0189] A substantial body of data strongly suggests that Frizzled molecules function as receptors or components of receptors for Wnt proteins. (See e.g., He, et al., Science 275:1652-1654 (1997.)) Deletional analysis indicated that the cysteine-rich domain (CRD) is responsible for conferring Wnt-binding or Wnt-dependent signaling to biological systems. Bhanot. et al., Nature 382:225-230 (1996). Because FRP contains a FZ-type CRD and is able to antagonize Wnt-dependent duplication of the dorsal axis in the Xenopus embryo assay (Finch, et al., P.N.A.S. 94:6770-6775 (1997), FRP is likely to be a receptor for a subset of Wnt family members. To test the hypothesis that FRP inhibits Wnt activity by binding Wnt proteins, the assays to elucidate the interaction of FRP with FRP binding proteins were designed.
[0190] Experimental systems to study Wnt binding and other interactions are problematic for a number of reasons. For years. Wnt receptor analysis has been hampered by the insolubility of Wnt proteins, which tend to remain associated with cell surfaces or extracellular matrix. Bradley, et al., EMBO J. 9:1569-1575 (1990). This property has impeded efforts to purify Wnts for tracer labeling and specific, sensitive receptor-ligand binding studies. Moreover, because vertebrates produce at least eight different Frizzleds Wang, et al., J. Biol. Chem. 271:4468-4476 (1996), six secreted Frizzled-related proteins (see e.g., Salic, et al., Development 124:4739-4748 (1997) and fifteen Wnts (Cadigan, et al., Genes Dev. 11:3286-3305 (1997), any cell is likely to endogenously express one or more molecules that could influence Wnt-Frizzled binding [not to mention proteoglycans, which also affect Wnt binding and activity. (See e.g., Häcker, et al., Development 124:3565-3573 (1997).] This would undoubtedly complicate the interpretation of experiments involving ectopic expression of any component of the putative Wnt-FZ binding complex.
[0191] As an alternative, cell-free systems to study the binding of FRP and Wnts were developed. These systems have the advantage of simplicity, as the profile of endogenous Frizzled/FRP/Wnt expression would not be an issue. Moreover, experiments now can be performed with purified recombinant FRP. One model system disclosed in detail below makes use of an ELISA type of format. Microtiter wells are first coated with purified FRP, and then blocked with a large excess of bovine serum albumin (BSA). To minimize the problems associated with solubilizing Wnts, initial studies focused on studying FRP binding to Wingless (Wg) because an expression system is available that releases Wg into conditioned medium. Van Leeuwen, et al., Nature 368:342-344 (1994). Although expression of a heat shock-Wg construct in transfected S2 insect cells results in only a small fraction of recombinant Wg in the media, it is sufficient for binding studies and obviates the need for detergents or other agents to extract the protein from cell surfaces or extracellular matrix. Medium from the heat shock-Wg cells or S2 vector controls is incubated in microtiter wells that have either been coated with FRP and blocked with BSA or only blocked with BSA. After washing, the wells are sequentially incubated with antibody to Wg, secondary antiserum (against the Wg antibody) conjugated to alkaline phosphatase, and p-nitrophenol phosphate. The last reagent is a substrate for the phosphatase; the development of yellow color is a measure of the Wg protein retained in the wells.
[0192] [0192]FIG. 13 provides an illustration of these results. FIG. 13 illustrates the binding of FRP and Wg. (A) FRP-Wg interaction in ELISA format. Falcon 96-well microtiter plates were coated with recombinant human FRP at 100 ng/well (FRP 100) or left blank (FRP 0) prior to blocking with 4% bovine serum albumin. Subsequently wells were incubated with serial dilutions of conditioned medium from S2 cells expressing Wg via a heat shock promoter (Wg) or medium from control S2 cells (S2). Following washing, wells were incubated sequentially with a rabbit polyclonal antiserum against Wg, goat anti-rabbit antiserum conjugated to alkaline phosphatase, and p-nitrophenol phosphate. Color development, monitored at 405 nm, was indicative of Wg binding in the well. Each data point is the mean±standard deviation of triplicate measurements; when not shown, deviation was smaller than size of symbol. (B) Immunoblotting of Wg. Samples of conditioned medium used in (A) were concentrated in Centricon-10 devices, resolved by 8% SDS-PAGE, transferred to Immobilon filters, blotted with Wg monoclonal antibody and analyzed by chemiluminescence. The arrow indicates band corresponding to Wg. Position of molecular mass markers is shown at left.
[0193] As shown in FIG. 13A, wells coated with 100 ng of FRP display specific and highly reproducible binding of Wg that varies with the dilution of conditioned medium. A small amount of non-specific binding is observed when relatively concentrated Wg-containing samples are incubated in wells that have not been coated with FRP. No background signal is seen in wells coated with FRP and incubated with medium from control S2 cells. This is consistent with the fact that control cells do not express detectable levels of Wg protein (FIG. 13B). Taken together, these data provide strong evidence that FRP is capable of binding Wg. These assays are described in detail below.
[0194] FRP-Wingless Standard ELISA Assay.
[0195] Wells of ELISA plate were coated with purified, recombinant FRP. After blocking with BSA, conditioned medium containing Wingless (Wg) was introduced. Following appropriate incubation period, Wg-containing medium was removed and bound Wg was detected by sequential addition of antibody to Wg, secondary antibody conjugated to alkaline phosphatase and p-nitrophenylphosphate. Amount of yellow color in well, determined by ELISA reader (spectrophotometer measuring absorbance at 405 nm), was a measure of bound Wg. Either the amount of FRP used to coat wells or the dilution of Wg medium (or control medium) could be varied to generate additional quantitative information about the interaction between FRP and Wg.
[0196] FRP coating of the wells was accomplished by diluting FRP in 0.02% sodium azide/PBS, and add 50 ul to each well. 100-300 ng FRP/well provides optimal results. The plate was then incubated at 37° C. for 2 hours in a moist environment. In this assay, FRP was not added to the first lane, which serves as a blank. Blocking was accomplished by removing the FRP solution from the wells and adding 100 ul of a 4% BSA in sodium azide/PBS (no need to wash) and incubating at 37° C. for 2 hours. Washing was accomplished by washing the wells 5 times with TAPS (0.05% Tween 20 and 0.02% NaN 3 /PBS). Wells were filled with squeeze bottle, and then blotted against paper towel.
[0197] Wg binding was accomplished diluting Wg-containing or control media in diluent solution (1% BSA in TAPS), and add 50 ul to each well and then incubating at room temperature overnight. The wells were then washed 5 times as disclosed above. The primary antibody was then added by diluting the anti-Wg antibody (mouse monoclonal) in diluent solution to 1:1000, and add 50 ul to each well and incubating at 37° C. for 2 hours. The wells were then washed 5 times as disclosed above.
[0198] The secondary antibody was added by diluting this secondary antibody (goat anti-mouse-alkaline phosphatase conjugate) in diluent solution (using a conjugate from TAGO Inc. cat #4650 at a 1:400 dilution); add 50 ul to each well and incubating at 37° C. or 2 hours. The wells were then washed 5 times as disclosed above. Substrate was prepared by dissolving the substrate, p-nitrophenolphosphate (Sigma cat #2640) in carbonate buffer (1 mM MgCl 2 /0.1M Na 2 CO 3 pH 9.8) to a final concentration of 2 mg/ml. 65 ul of this substrate was then added to each well and read OD at 405 nm.
[0199] Competition Assay
[0200] Similar to standard assay discussed above, except Wg-containing medium is preincubated with varying concentrations of FRP or related protein to assess the ability of these proteins to bind Wg. This is manifested by a reduction in Wingless binding to the FRP-coated ELISA well. Typically preincubation is performed at room temperature for 1 hour.
[0201] A related variation of the ELISA involves preincubation of Wg medium with proteoglycan such as heparin to assess its effect on subsequent binding to FRP coated wells. Medium can be preincubated with heparin and FRP simultaneously. As an alternative, heparin and/or FRP (or FRP-related proteins) can be added to the medium in the ELISA well without prior incubation. FIG. 14 provides an illustration of these results. Specifically, FIG. 14 illustrates how soluble FRP (ng of FRP/50 ul of Wg containing medium) influences Wg binding to bound FRP in ELISA format.
[0202] Preparation of Conditioned Medium from Drosophila S2 Cells—Control S2 and Cells Transfected with Heat Shock—Wingless Construct
[0203] Growth medium utilized in this assay was Schneider's Drosophila Medium (Gibco cat #11720-034)+supplements. The medium for conditioning was Shields and Sang M3 Insect Medium (Sigma cat#S3652).
[0204] The Recovery of frozen cells appears to be the time when cells are most fragile (aside from recovery period, the cells are quite hardy). A key point is to avoid diluting cells until they clearly are thriving. Specifically, an ampule of ˜10 million cells in a T-25 flask with final volume of 5-6 ml medium consisting of: Schneider's medium, 10% fetal bovine serum, penicillin (100 units/ml) and streptomycin (100 ug/ml); incubated at 26° C. Periodically, a small amount (1-2 ml) of fresh medium, prewarmed to room temperature was added to the solution, allowing the cell population to become quite dense (turbid) prior to subculture.
[0205] For the initial subculture, the cell suspension was transferred with pipette to a T-75 flask containing 20-25 ml of the above medium; typically suspension was diluted from 1:2 to 1:10, or perhaps even greater. Because some cells will remain adherent to the original T-25 flask, fresh medium was added to it to maintain a viable culture. Cells typically grow well at this point. For the subsequent subculture, dense (turbid) cultures were split, usually 1:10, into T-175 flasks for experiments. Cultures become dense and ready for use in ˜1 week.
[0206] Heat Shock Protocol:
[0207] The heat shock protocol was carried out by the following steps:
[0208] 1. Incubate culture at 37° C. for 50 minutes;
[0209] 2. Transfer culture to room temp (26° C.), and incubate for 40 minutes;
[0210] 3. Pellet cells at low speed (3000 rpm, 5 minutes in standard lab bench centrifuge);
[0211] 4. Resuspend pellets 3 times with serum-free Shields and Sang M3 Insect Medium, 20-40 ml/wash and obtain cell count (alternatively one can determine cell count with aliquot of sample during step 1), (typically, cell number is determined after the second resuspension by removing an aliquot, diluting it 5-fold and measuring cell count with a hemacytometer);
[0212] 5. After the third wash, resuspend cells in Shields and Sang medium at a concentration of 25 million cells/ml and incubate for 5 hours at 26° C.; and
[0213] 6. Pellet cells as before and collect supernatant for use as conditioned medium.
[0214] FRP-Wg Crosslinking
[0215] FRP-Wg interactions in a cell-free setting were studied first, as variables are more easily controlled in such systems than in cellular assays. The crosslinking analysis may be extended to cellular systems. In particular, one can assess FRP binding to epitope-tagged, Wnt family members expressed in appropriate host cells such as NIH/3T3 fibroblasts. Crosslinked complexes consisting of 125 I-FRP and Wnt protein were immunoprecipitated with antibodies directly against the epitope tag.
[0216] A method for detection of FRP-Wg complexes by crosslinking analysis is as follows.
[0217] I. The iodination reaction can be accomplished by reacting 10 ug of purified recombinant FRP and 1 milliCurie of Na 125 I with chloramine-T for 1 minute at room temperature (additional details essentially as described in Bottaro D P et al. J Biol. Chem 265: 12767-12770, (1990)).
[0218] The 125 I-FRP can be isolated by heparin-Sepharose chromatography. Specifically, tracer was eluted with phosphate buffer (pH 7.4) containing 1.0 M NaCl and 1 mg/ml bovine serum albumin (BSA). Certain iodinated FRP derivatives can be recovered on desalting columns (containing resins such as G10) that serve to separate protein tracer from free sodium iodide. Tracer was stored frozen and subjected to not more than a few rounds of freeze-thawing prior to use.
[0219] II. Binding of tracer to Wg (all performed at room temperature) can be undertaken as follows. Typically ˜1 microCurie (though amount could vary), of 125 I-FRP, was incubated with medium from Wg—expressing S2 cells (or control S2 cells) in a final volume of 50 ul for 40 minute. Varying amounts of additional reagents, such as heparin and/or unlabeled FRP, were added in some experiments. After binding period, crosslinking reagent bis(sulfosuccinimidyl) suberate (BS 3 ) was added at a final concentration of 1 mM and incubation continued for 20 minutes. The crosslinking reaction was terminated by the addition of Tris-HCl and glycine (final concentrations were 1 mM and 20 mM, respectively).
[0220] III. Detection of crosslinked complexes was undertaken by incubating all or most of the reaction mixture with antibody directed against Wg overnight at 4° C. Protein G-coupled resin (˜50 ul slurry of GammaBind, Pharmacia) was then added along with buffer A (50 mM HEPES pH 7.4, 5 mM EDTA, 50 mM NaCl, 1% Triton X-100, 6 mM Na 4 P 2 O 7 , 50 mM NaF. 0.35 mg/ml PMSF, 10 ug/ml aprotinin and 10 ug/ml leupeptin) to bring final volume to ˜0.5 ml. The reaction mixture was incubated for 1 hour at 4° C. in a rotary shaker. Typically a monoclonal antibody to Wg was used for immunoprecipitation, final concentration of 10 ug/ml (Brook et al., Science 273: 1373-1377 (1996)). After incubation, immune complexes were pelleted by centrifugation in microfuge (3 min at 14,000 rpm). Pellets were washed 3 times, each with 1 ml of buffer A.
[0221] Laemmli sample buffer was added to pellets, samples boiled for 4 minutes and proteins resolved by SDS-PAGE (8% polyacrylamide). In some instances. aliquots were removed from reaction mixture prior to addition of antibody and processed for electrophoresis. Gels were fixed (in 20%methanol, 10% acetic acid, 70% water) for 30 minutes at room temperature. dried and exposed to X-ray film at −70° C. for autoradiography.
[0222] [0222]FIGS. 15 and 16 illustrate these 125 I-FRP-Wg Crosslinking reactions under different experimental conditions. Briefly, FIG. 15 shows the effects of varying the concentration of heparin in crosslinking reactions between 125 I-FRP and Wg, with the crosslinked molecules being immunoprecipitated with an anti-Wg monoclonal antibody and separated by gel electrophoresis. In this assay, varying amounts of heparin (Fisher, porcine intestinal) were incubated with 125 I-FRP (approximately 1 microCurie) and conditioned medium from Wg—expressing or control S2 cells at room temperature for 40 min. After a subsequent incubation with BS3 crosslinking agent the reaction was quenched and the mixture was subjected to immunoprecipitation with monoclonal antibody to Wg. Precipitates were resolved by SDS-PAGE and labeled protein detected by autoradiography of dried gels.
[0223] [0223]FIG. 16 shows the effects of varying the concentration of unlabelled FRP or FRP derivatives in crosslinking reactions between 125 I-FRP and Wg, with the crosslinked molecules being immunoprecipitated with an anti-Wg monoclonal antibody and separated by gel electrophoresis. Briefly, varying concentrations of unlabeled FRP or FRP derivatives were incubated with 125 I-FRP, conditioned medium from Wg-expressing or control S2 cells and heparin at 1 ug/ml. After a subsequent incubation with BS3 crosslinking agent, the reaction was quenched and the mixture was subjected to immunoprecipitation with monoclonal antibody to Wg. Precipitates were resolved by SDS-PAGE and labeled protein detected by autoradiography of dried gels.
Example 9
[0224] Modulation of Embryonic Kidney Cell Tubulogenesis By FRP.
[0225] Induction of tubulogenesis in culture of isolated metanephric mesenchyme was assessed. This organ culture system was described in an article by Karavanova I D et al. (Development 122: 4159-4167, 1996). In brief, kidneys were removed from F344 rat embryos 13 days post coitum. Metanephric mesenchyme was separated from ureteric bud by enzyme treatment, and cultured on collagen-coated filters. Tissue incubated with serum-free conditioned medium from a rat ureteric bud cell line (RUB1) supplemented with basic FGF and TGFα was induced to differentiate into epithelial tubular structures corresponding to nephrons.
[0226] Remarkably, if cultures treated with RUB1 conditioned medium, basic FGF and TGFα also received purified recombinant FRP (5 ug/ml) the induction of tubular structures was completely inhibited. Interestingly, the mesenchymal cells did not die; they even appeared to increase in number and the cultures grew larger during the 3 day incubation period. This result, an increase in condensed mesenchyme but an apparent failure to differentiate into epithelial cells and subsequent failure to form tubular structures, was observed in vivo in mice that were targeted for loss of Wnt 4 expression (Stark K et al. Nature 372: 679-683, 1994). Moreover, other Wnt family members are expressed in kidney and may participate in this process of differentiation and morphogenesis (see Karavanova et al. 1996). Thus, this preliminary result provides additional support for the idea that FRP can function as a soluble antagonist of Wnt activity. On a more elementary level, it demonstrates that purified, recombinant FRP has biological activity.
1
27
1
2078
DNA
Homo sapiens
1
cctgcagcct ccggagtcag tgccgcgcgc ccgccgcccc gcgccttcct gctcgccgca 60
cctccgggag ccggggcgca cccagcccgc agcgccgcct ccccgcccgc gccgcctccg 120
accgcaggcc gagggccgcc actggccggg gggaccgggc agcagcttgc ggccgcggag 180
ccgggcaacg ctggggactg cgccttttgt ccccggaggt ccctggaagt ttgcggcagg 240
acgcgcgcgg ggaggcggcg gaggcagccc cgacgtcgcg gagaacaggg cgcagagccg 300
gcatgggcat cgggcgcagc gaggggggcc gccgcggggc agccctgggc gtgctgctgg 360
cgctgggcgc ggcgcttctg gccgtgggct cggccagcga gtacgactac gtgagcttcc 420
agtcggacat cggcccgtac cagagcgggc gcttctacac caagccacct cagtgcgtgg 480
acatccccgc ggacctgcgg ctgtgccaca acgtgggcta caagaagatg gtgctgccca 540
acctgctgga gcacgagacc atggcggagg tgaagcagca ggccagcagc tgggtgcccc 600
tgctcaacaa gaactgccac gccgggaccc aggtcttcct ctgctcgctc ttcgcgcccg 660
tctgcctgga ccggcccatc tacccgtgtc gctggctctg cgaggccgtg cgcgactcgt 720
gcgagccggt catgcagttc ttcggcttct actggcccga gatgcttaag tgtgacaagt 780
tcccggaggg ggacgtctgc atcgccatga cgccgcccaa tgccaccgaa gcctccaagc 840
cccaaggcac aacggtgtgt cctccctgtg acaacgagtt gaaatctgag gccatcattg 900
aacatctctg tgccagcgag tttgcactga ggatgaaaat aaaagaagtg aaaaaagaaa 960
atggcgacaa gaagattgtc cccaagaaga agaagcccct gaagttgggg cccatcaaga 1020
agaaggacct gaagaagctt gtgctgtacc tgaagaatgg ggctgactgt ccctgccacc 1080
agctggacaa cctcagccac cacttcctca tcatgggccg caaggtgaag agccagtact 1140
tgctgacggc catccacaag tgggacaaga aaaacaagga gttcaaaaac ttcatgaaga 1200
aaatgaaaaa ccatgagtgc cccacctttc agtccgtgtt taagtgattc tcccgggggc 1260
agggtgggga gggagcctcg ggtggggtgg gagcgggggg gacagtgccc gggaacccgt 1320
ggtcacacac acgcactgcc ctgtcagtag tggacattgt aatccagtcg gcttgttctt 1380
gcagcattcc cgctcccttt ccctccatag ccacgctcca aaccccaggg tagccatggc 1440
cgggtaaagc aagggccatt tagattagga aggtttttaa gatccgcaat gtggagcagc 1500
agccactgca caggaggagg tgacaaacca tttccaacag caacacagcc actaaaacac 1560
aaaaaggggg attgggcgga aagtgagagc cagcagcaaa aactacattt tgcaacttgt 1620
tggtgtggat ctattggctg atctatgcct ttcaactaga aaattctaat gattggcaag 1680
tcacgttgtt ttcaggtcca gagtagtttc tttctgtctg ctttaaatgg aaacagactc 1740
ataccacact tacaattaag gtcaagccca gaaagtgata agtgcaggga ggaaaagtgc 1800
aagtccatta tctaatagtg acagcaaagg gaccagggga gaggcattgc cttctctgcc 1860
cacagtcttt ccgtgtgatt gtctttgaat ctgaatcagc cagtctcaga tgccccaaag 1920
tttcggttcc tatgagcccg gggcatgatc tgatccccaa gacatgtgga ggggcagcct 1980
gtgcctgcct ttgtgtcaga aaaaggaaac cacagtgagc ctgagagaga cggcgatttt 2040
cgggctgaga aggcagtagt tttcaaaaca catagtta 2078
2
2075
DNA
Homo sapiens
2
cctgcagcct ccggagtcag tgccgcgcgc ccgccgcccc gcgccttcct gctcgccgca 60
cctccgggag ccggggcgca cccagcccgc agcgccgcct ccccgcccgc gccgcctccg 120
accgcaggcc gagggccgcc actggccggg gggaccgggc agcagcttgc ggccgcggag 180
ccgggcaacg ctggggactg cgccttttgt ccccggaggt ccctggaagt ttgcggcagg 240
acgcgcgcgg ggaggcggcg gaggcagccc cgacgtcgcg gagaacaggg cgcagagccg 300
gcatgggcat cgggcgcagc gaggggggcc gccgcggggc cctgggcgtg ctgctggcgc 360
tgggcgcggc gcttctggcc gtgggctcgg ccagcgagta cgactacgtg agcttccagt 420
cggacatcgg cccgtaccag agcgggcgct tctacaccaa gccacctcag tgcgtggaca 480
tccccgcgga cctgcggctg tgccacaacg tgggctacaa gaagatggtg ctgcccaacc 540
tgctggagca cgagaccatg gcggaggtga agcagcaggc cagcagctgg gtgcccctgc 600
tcaacaagaa ctgccacgcc gggacccagg tcttcctctg ctcgctcttc gcgcccgtct 660
gcctggaccg gcccatctac ccgtgtcgct ggctctgcga ggccgtgcgc gactcgtgcg 720
agccggtcat gcagttcttc ggcttctact ggcccgagat gcttaagtgt gacaagttcc 780
cggaggggga cgtctgcatc gccatgacgc cgcccaatgc caccgaagcc tccaagcccc 840
aaggcacaac ggtgtgtcct ccctgtgaca acgagttgaa atctgaggcc atcattgaac 900
atctctgtgc cagcgagttt gcactgagga tgaaaataaa agaagtgaaa aaagaaaatg 960
gcgacaagaa gattgtcccc aagaagaaga agcccctgaa gttggggccc atcaagaaga 1020
aggacctgaa gaagcttgtg ctgtacctga agaatggggc tgactgtccc tgccaccagc 1080
tggacaacct cagccaccac ttcctcatca tgggccgcaa ggtgaagagc cagtacttgc 1140
tgacggccat ccacaagtgg gacaagaaaa acaaggagtt caaaaacttc atgaagaaaa 1200
tgaaaaacca tgagtgcccc acctttcagt ccgtgtttaa gtgattctcc cgggggcagg 1260
gtggggaggg agcctcgggt ggggtgggag cgggggggac agtgcccggg aacccgtggt 1320
cacacacacg cactgccctg tcagtagtgg acattgtaat ccagtcggct tgttcttgca 1380
gcattcccgc tccctttccc tccatagcca cgctccaaac cccagggtag ccatggccgg 1440
gtaaagcaag ggccatttag attaggaagg tttttaagat ccgcaatgtg gagcagcagc 1500
cactgcacag gaggaggtga caaaccattt ccaacagcaa cacagccact aaaacacaaa 1560
aagggggatt gggcggaaag tgagagccag cagcaaaaac tacattttgc aacttgttgg 1620
tgtggatcta ttggctgatc tatgcctttc aactagaaaa ttctaatgat tggcaagtca 1680
cgttgttttc aggtccagag tagtttcttt ctgtctgctt taaatggaaa cagactcata 1740
ccacacttac aattaaggtc aagcccagaa agtgataagt gcagggagga aaagtgcaag 1800
tccattatct aatagtgaca gcaaagggac caggggagag gcattgcctt ctctgcccac 1860
agtctttccg tgtgattgtc tttgaatctg aatcagccag tctcagatgc cccaaagttt 1920
cggttcctat gagcccgggg catgatctga tccccaagac atgtggaggg gcagcctgtg 1980
cctgcctttg tgtcagaaaa aggaaaccac agtgagcctg agagagacgg cgattttcgg 2040
gctgagaagg cagtagtttt caaaacacat agtta 2075
3
314
PRT
Homo sapiens
3
Met Gly Ile Gly Arg Ser Glu Gly Gly Arg Arg Gly Ala Ala Leu Gly
1 5 10 15
Val Leu Leu Ala Leu Gly Ala Ala Leu Leu Ala Val Gly Ser Ala Ser
20 25 30
Glu Tyr Asp Tyr Val Ser Phe Gln Ser Asp Ile Gly Pro Tyr Gln Ser
35 40 45
Gly Arg Phe Tyr Thr Lys Pro Pro Gln Cys Val Asp Ile Pro Ala Asp
50 55 60
Leu Arg Leu Cys His Asn Val Gly Tyr Lys Lys Met Val Leu Pro Asn
65 70 75 80
Leu Leu Glu His Glu Thr Met Ala Glu Val Lys Gln Gln Ala Ser Ser
85 90 95
Trp Val Pro Leu Leu Asn Lys Asn Cys His Ala Gly Thr Gln Val Phe
100 105 110
Leu Cys Ser Leu Phe Ala Pro Val Cys Leu Asp Arg Pro Ile Tyr Pro
115 120 125
Cys Arg Trp Leu Cys Glu Ala Val Arg Asp Ser Cys Glu Pro Val Met
130 135 140
Gln Phe Phe Gly Phe Tyr Trp Pro Glu Met Leu Lys Cys Asp Lys Phe
145 150 155 160
Pro Glu Gly Asp Val Cys Ile Ala Met Thr Pro Pro Asn Ala Thr Glu
165 170 175
Ala Ser Lys Pro Gln Gly Thr Thr Val Cys Pro Pro Cys Asp Asn Glu
180 185 190
Leu Lys Ser Glu Ala Ile Ile Glu His Leu Cys Ala Ser Glu Phe Ala
195 200 205
Leu Arg Met Lys Ile Lys Glu Val Lys Lys Glu Asn Gly Asp Lys Lys
210 215 220
Ile Val Pro Lys Lys Lys Lys Pro Leu Lys Leu Gly Pro Ile Lys Lys
225 230 235 240
Lys Asp Leu Lys Lys Leu Val Leu Tyr Leu Lys Asn Gly Ala Asp Cys
245 250 255
Pro Cys His Gln Leu Asp Asn Leu Ser His His Phe Leu Ile Met Gly
260 265 270
Arg Lys Val Lys Ser Gln Tyr Leu Leu Thr Ala Ile His Lys Trp Asp
275 280 285
Lys Lys Asn Lys Glu Phe Lys Asn Phe Met Lys Lys Met Lys Asn His
290 295 300
Glu Cys Pro Thr Phe Gln Ser Val Phe Lys
305 310
4
313
PRT
Homo sapiens
4
Met Gly Ile Gly Arg Ser Glu Gly Gly Arg Arg Gly Ala Leu Gly Val
1 5 10 15
Leu Leu Ala Leu Gly Ala Ala Leu Leu Ala Val Gly Ser Ala Ser Glu
20 25 30
Tyr Asp Tyr Val Ser Phe Gln Ser Asp Ile Gly Pro Tyr Gln Ser Gly
35 40 45
Arg Phe Tyr Thr Lys Pro Pro Gln Cys Val Asp Ile Pro Ala Asp Leu
50 55 60
Arg Leu Cys His Asn Val Gly Tyr Lys Lys Met Val Leu Pro Asn Leu
65 70 75 80
Leu Glu His Glu Thr Met Ala Glu Val Lys Gln Gln Ala Ser Ser Trp
85 90 95
Val Pro Leu Leu Asn Lys Asn Cys His Ala Gly Thr Gln Val Phe Leu
100 105 110
Cys Ser Leu Phe Ala Pro Val Cys Leu Asp Arg Pro Ile Tyr Pro Cys
115 120 125
Arg Trp Leu Cys Glu Ala Val Arg Asp Ser Cys Glu Pro Val Met Gln
130 135 140
Phe Phe Gly Phe Tyr Trp Pro Glu Met Leu Lys Cys Asp Lys Phe Pro
145 150 155 160
Glu Gly Asp Val Cys Ile Ala Met Thr Pro Pro Asn Ala Thr Glu Ala
165 170 175
Ser Lys Pro Gln Gly Thr Thr Val Cys Pro Pro Cys Asp Asn Glu Leu
180 185 190
Lys Ser Glu Ala Ile Ile Glu His Leu Cys Ala Ser Glu Phe Ala Leu
195 200 205
Arg Met Lys Ile Lys Glu Val Lys Lys Glu Asn Gly Asp Lys Lys Ile
210 215 220
Val Pro Lys Lys Lys Lys Pro Leu Lys Leu Gly Pro Ile Lys Lys Lys
225 230 235 240
Asp Leu Lys Lys Leu Val Leu Tyr Leu Lys Asn Gly Ala Asp Cys Pro
245 250 255
Cys His Gln Leu Asp Asn Leu Ser His His Phe Leu Ile Met Gly Arg
260 265 270
Lys Val Lys Ser Gln Tyr Leu Leu Thr Ala Ile His Lys Trp Asp Lys
275 280 285
Lys Asn Lys Glu Phe Lys Asn Phe Met Lys Lys Met Lys Asn His Glu
290 295 300
Cys Pro Thr Phe Gln Ser Val Phe Lys
305 310
5
9
PRT
Homo sapiens
5
Asn Val Gly Tyr Lys Lys Met Val Leu
1 5
6
9
PRT
Homo sapiens
VARIANT
(8)
Any amino acid
6
Phe Tyr Thr Lys Pro Pro Gln Xaa Val
1 5
7
40
PRT
Homo sapiens
VARIANT
(20)...(31)
Any amino acid
7
Phe Gln Ser Asp Ile Gly Pro Tyr Gln Ser Gly Arg Phe Tyr Thr Lys
1 5 10 15
Pro Pro Gln Xaa Val Asp Ile Pro Ala Asp Leu Arg Leu Xaa Xaa Asn
20 25 30
Val Gly Tyr Lys Lys Met Val Leu
35 40
8
10
DNA
Homo sapiens
8
gccrccatgg 10
9
111
PRT
Homo sapiens
9
Cys Gln Pro Ile Ser Ile Pro Leu Cys Thr Asp Ile Ala Tyr Asn Gln
1 5 10 15
Thr Ile Met Pro Asn Leu Leu Gly His Thr Asn Gln Glu Asp Ala Gly
20 25 30
Leu Glu Val His Gln Phe Tyr Pro Leu Val Lys Gln Cys Ser Pro Glu
35 40 45
Leu Arg Phe Phe Leu Cys Ser Met Tyr Ala Pro Val Cys Thr Val Leu
50 55 60
Glu Gln Ala Ile Pro Pro Cys Arg Ser Ile Cys Glu Arg Ala Arg Gln
65 70 75 80
Gly Cys Glu Ala Leu Met Asn Lys Phe Gly Phe Gln Trp Pro Glu Arg
85 90 95
Leu Arg Cys Glu His Phe Pro Arg His Gly Ala Glu Gln Ile Cys
100 105 110
10
115
PRT
Homo sapiens
10
Cys Gln Glu Ile Thr Val Pro Met Cys Arg Gly Ile Gly Tyr Asn Leu
1 5 10 15
Thr His Met Pro Asn Gln Phe Asn His Asp Thr Gln Asp Glu Ala Gly
20 25 30
Leu Glu Val His Gln Phe Trp Pro Leu Val Glu Ile Gln Cys Ser Pro
35 40 45
Asp Leu Arg Phe Phe Leu Cys Thr Met Tyr Thr Pro Ile Cys Leu Pro
50 55 60
Asp Tyr His Lys Pro Leu Pro Pro Cys Arg Ser Val Cys Glu Arg Ala
65 70 75 80
Lys Ala Gly Cys Ser Pro Leu Met Arg Gln Tyr Gly Phe Ala Trp Pro
85 90 95
Glu Arg Met Ser Cys Asp Arg Leu Pro Val Leu Gly Arg Asp Ala Glu
100 105 110
Val Leu Cys
115
11
106
PRT
Mus musculus
11
Cys Glu Pro Ile Thr Leu Arg Met Cys Gln Asp Leu Pro Tyr Asn Thr
1 5 10 15
Thr Phe Met Pro Asn Leu Leu Asn His Tyr Asp Gln Gln Thr Ala Ala
20 25 30
Leu Ala Met Glu Pro Phe His Pro Met Val Asn Leu Asp Cys Ser Arg
35 40 45
Asp Phe Arg Pro Phe Leu Cys Ala Leu Tyr Ala Pro Ile Cys Met Glu
50 55 60
Tyr Gly Arg Val Thr Leu Pro Cys Arg Arg Leu Cys Gln Arg Ala Tyr
65 70 75 80
Ser Glu Cys Ser Lys Leu Met Glu Met Phe Gly Val Pro Trp Pro Glu
85 90 95
Asp Met Glu Cys Ser Arg Phe Pro Asp Cys
100 105
12
114
PRT
Mus musculus
12
Cys Asp Pro Ile Arg Ile Ala Met Cys Gln Asn Leu Gly Tyr Asn Val
1 5 10 15
Thr Lys Met Pro Asn Leu Val Gly His Glu Leu Gln Thr Asp Ala Glu
20 25 30
Leu Gln Leu Thr Thr Phe Thr Pro Leu Ile Gln Tyr Gly Cys Ser Ser
35 40 45
Gln Leu Gln Phe Phe Leu Cys Ser Val Tyr Val Pro Met Cys Thr Glu
50 55 60
Lys Ile Asn Ile Pro Ile Gly Pro Cys Gly Gly Met Cys Leu Ser Val
65 70 75 80
Lys Arg Arg Cys Glu Pro Val Leu Arg Glu Phe Gly Phe Ala Trp Pro
85 90 95
Asp Thr Leu Asn Cys Ser Lys Phe Pro Pro Gln Asn Asp His Asn His
100 105 110
Met Cys
13
106
PRT
Mus musculus
13
Cys Glu Pro Ile Thr Val Pro Arg Cys Met Lys Met Thr Tyr Asn Met
1 5 10 15
Thr Phe Phe Pro Asn Leu Met Gly His Tyr Asp Gln Gly Ile Ala Ala
20 25 30
Val Glu Met Gly His Phe Leu His Leu Ala Asn Leu Glu Cys Ser Pro
35 40 45
Asn Ile Glu Met Phe Leu Cys Gln Ala Phe Ile Pro Thr Cys Thr Glu
50 55 60
Gln Ile His Val Val Leu Pro Cys Arg Lys Leu Cys Glu Lys Ile Val
65 70 75 80
Ser Asp Cys Lys Lys Leu Met Asp Thr Phe Gly Ile Arg Trp Pro Glu
85 90 95
Glu Leu Glu Cys Asn Arg Leu Pro His Cys
100 105
14
111
PRT
Mus musculus
14
Cys Gln Pro Ile Ser Ile Pro Leu Cys Thr Asp Ile Ala Tyr Asn Gln
1 5 10 15
Thr Ile Leu Pro Asn Leu Leu Gly His Thr Asn Gln Glu Asp Ala Gly
20 25 30
Leu Glu Val His Gln Phe Tyr Pro Leu Val Lys Val Gln Cys Ser Pro
35 40 45
Glu Leu Arg Phe Phe Leu Cys Ser Met Tyr Ala Pro Val Cys Thr Val
50 55 60
Leu Asp Gln Ala Ile Pro Pro Cys Arg Ser Leu Cys Glu Arg Ala Arg
65 70 75 80
Gly Cys Glu Ala Leu Met Asn Lys Phe Gly Phe Gln Trp Pro Glu Arg
85 90 95
Leu Arg Cys Glu Asn Phe Pro Val His Gly Ala Gly Glu Ile Cys
100 105 110
15
114
PRT
Mus musculus
15
Cys Gln Glu Ile Thr Val Pro Leu Cys Lys Gly Ile Gly Tyr Asn Tyr
1 5 10 15
Thr Tyr Met Pro Asn Gln Phe Asn His Asp Thr Gln Asp Glu Ala Gly
20 25 30
Leu Glu Val His Gln Phe Trp Pro Leu Val Glu Ile Gln Cys Ser Pro
35 40 45
Asp Leu Lys Phe Phe Leu Cys Ser Met Tyr Thr Pro Ile Cys Leu Glu
50 55 60
Asp Tyr Lys Lys Pro Leu Pro Pro Cys Arg Ser Val Cys Glu Arg Ala
65 70 75 80
Lys Ala Gly Cys Ala Pro Leu Met Arg Gln Tyr Gly Phe Ala Trp Pro
85 90 95
Asp Arg Met Arg Cys Asp Arg Leu Pro Glu Gln Gly Asn Pro Asp Thr
100 105 110
Leu Cys
16
111
PRT
Rattus norvegicus
16
Cys Gln Pro Ile Ser Ile Pro Leu Cys Thr Asp Ile Ala Tyr Asn Gln
1 5 10 15
Thr Ile Met Pro Asn Leu Leu Gly His Thr Asn Gln Glu Asp Ala Gly
20 25 30
Leu Glu Val His Gln Phe Tyr Pro Leu Val Lys Val Gln Cys Ser Ala
35 40 45
Glu Leu Lys Phe Phe Leu Cys Ser Met Tyr Ala Pro Val Cys Thr Val
50 55 60
Leu Glu Gln Ala Leu Pro Pro Cys Arg Ser Leu Cys Glu Arg Ala Gln
65 70 75 80
Gly Cys Glu Ala Leu Met Asn Lys Phe Gly Phe Gln Trp Pro Asp Thr
85 90 95
Leu Lys Cys Glu Lys Phe Pro Val His Gly Ala Gly Glu Leu Cys
100 105 110
17
112
PRT
Rattus norvegicus
17
Cys Gln Pro Ile Ser Ile Pro Leu Cys Thr Asp Ile Ala Tyr Asn Gln
1 5 10 15
Thr Ile Met Pro Asn Leu Leu Gly His Thr Asn Gln Glu Asp Ala Gly
20 25 30
Leu Glu Val His Gln Phe Tyr Pro Leu Val Lys Val Gln Cys Ser Pro
35 40 45
Glu Leu Arg Phe Phe Leu Cys Ser Met Tyr Ala Pro Val Cys Thr Val
50 55 60
Leu Glu Gln Ala Ile Pro Pro Cys Arg Ser Ile Cys Glu Arg Ala Arg
65 70 75 80
Gln Gly Cys Glu Ala Leu Met Asn Lys Phe Gly Phe Gln Trp Pro Glu
85 90 95
Arg Leu Arg Cys Glu His Phe Pro Arg His Gly Ala Glu Gln Ile Cys
100 105 110
18
111
PRT
Drosophila melanogaster
18
Cys Glu Pro Ile Thr Ile Ser Ile Cys Lys Asn Ile Pro Tyr Asn Met
1 5 10 15
Thr Ile Met Pro Asn Leu Ile Gly His Thr Lys Gln Glu Glu Ala Gly
20 25 30
Leu Glu Val His Gln Phe Ala Pro Leu Val Lys Ile Gly Cys Ser Asp
35 40 45
Asp Leu Gln Leu Phe Leu Cys Ser Leu Tyr Val Pro Val Cys Thr Ile
50 55 60
Leu Glu Arg Pro Ile Pro Pro Cys Arg Ser Leu Cys Glu Ser Ala Arg
65 70 75 80
Val Cys Glu Lys Leu Met Lys Thr Tyr Asn Phe Asn Trp Pro Glu Asn
85 90 95
Leu Glu Cys Ser Lys Phe Pro Val His Gly Gly Glu Asp Leu Cys
100 105 110
19
109
PRT
Homo sapiens
19
Cys Val Asp Ile Pro Ala Asp Leu Arg Leu Cys His Asn Val Gly Tyr
1 5 10 15
Lys Lys Met Val Leu Pro Asn Leu Leu Glu His Glu Thr Met Ala Glu
20 25 30
Val Lys Gln Gln Ala Ser Ser Trp Val Pro Leu Leu Asn Lys Asn Cys
35 40 45
His Ala Gly Thr Gln Val Phe Leu Cys Ser Leu Phe Ala Pro Val Cys
50 55 60
Leu Asp Arg Pro Ile Tyr Pro Cys Arg Trp Leu Cys Glu Ala Val Arg
65 70 75 80
Asp Ser Cys Glu Pro Val Met Gln Phe Phe Gly Phe Tyr Trp Pro Glu
85 90 95
Met Leu Lys Cys Asp Lys Phe Pro Glu Gly Asp Val Cys
100 105
20
114
PRT
Drosophila melanogaster
20
Cys Glu Glu Ile Thr Ile Pro Met Cys Arg Gly Ile Gly Tyr Asn Met
1 5 10 15
Thr Ser Phe Pro Asn Glu Met Asn His Glu Thr Gln Asp Glu Ala Gly
20 25 30
Leu Glu Val His Gln Phe Trp Pro Leu Val Glu Ile Lys Cys Ser Pro
35 40 45
Asp Leu Lys Phe Phe Leu Cys Ser Met Tyr Thr Pro Ile Cys Leu Glu
50 55 60
Asp Tyr His Lys Pro Leu Pro Val Cys Arg Ser Val Cys Glu Arg Ala
65 70 75 80
Arg Ser Gly Cys Ala Pro Ile Met Gln Gln Tyr Ser Phe Glu Trp Pro
85 90 95
Glu Arg Met Ala Cys Glu His Leu Pro Leu His Gly Asp Pro Asp Asn
100 105 110
Leu Cys
21
114
PRT
Caenorhabditis elegans
21
Cys Gln Lys Val Asp His Glu Met Cys Asn Asp Leu Pro Tyr Asn Leu
1 5 10 15
Thr Ser Phe Pro Asn Leu Val Asp Glu Glu Ser Trp Lys Asp Ala Ser
20 25 30
Glu Ser Ile Leu Thr Tyr Lys Pro Leu Leu Ser Val Val Cys Ser Glu
35 40 45
Gln Leu Lys Phe Phe Leu Cys Ser Val Tyr Phe Pro Met Cys Asn Glu
50 55 60
Lys Leu Ala Asn Pro Ile Gly Pro Cys Arg Pro Leu Cys Leu Ser Val
65 70 75 80
Gln Glu Lys Cys Leu Pro Val Leu Glu Ser Phe Gly Phe Lys Trp Pro
85 90 95
Asp Val Ile Arg Cys Asp Lys Phe Pro Leu Glu Asn Asn Arg Glu Lys
100 105 110
Met Cys
22
110
PRT
Mus musculus
22
Cys Leu Pro Leu Pro Pro Thr Leu Thr Leu Cys Ser Arg Leu Gly Ile
1 5 10 15
Gly His Phe Trp Leu Pro Asn His Leu His His Thr Asp Ser Val Glu
20 25 30
Val Glu Ala Thr Val Gln Ala Trp Gly Arg Phe Leu His Thr Asn Cys
35 40 45
His Pro Phe Leu Ala Trp Phe Phe Cys Leu Leu Leu Ala Pro Ser Cys
50 55 60
Gly Pro Gly Pro Pro Pro Pro Leu Pro Pro Cys Arg Gln Phe Cys Glu
65 70 75 80
Ala Leu Glu Asp Glu Cys Trp Asn Tyr Leu Ala Gly Asp Arg Leu Pro
85 90 95
Val Val Cys Ala Ser Leu Pro Ser Gln Glu Asp Gly Tyr Cys
100 105 110
23
112
PRT
Homo sapiens
23
Cys Glu Pro Val Arg Ile Pro Leu Cys Lys Ser Leu Pro Trp Asn Met
1 5 10 15
Thr Lys Met Pro Asn His Leu His Ser Thr Gln Ala Asn Ala Ile Leu
20 25 30
Ala Ile Glu Gln Phe Glu Gly Leu Leu Gly Thr His Cys Ser Pro Asp
35 40 45
Leu Leu Phe Phe Leu Cys Ala Met Tyr Ala Pro Ile Cys Thr Ile Asp
50 55 60
Phe Gln His Glu Pro Ile Asn Pro Cys Lys Ser Val Cys Glu Arg Ala
65 70 75 80
Arg Gln Gly Cys Glu Pro Ile Leu Ile Lys Tyr Arg His Ser Trp Pro
85 90 95
Glu Asn Leu Ala Cys Glu Glu Leu Pro Val Tyr Asp Arg Gly Val Cys
100 105 110
24
113
PRT
Mus musculus
24
Cys Lys Pro Ile Pro Ala Asn Leu Gln Leu Cys His Gly Ile Glu Tyr
1 5 10 15
Gln Asn Met Arg Leu Pro Asn Leu Leu Gly His Glu Thr Met Lys Glu
20 25 30
Val Leu Glu Gln Ala Gly Ala Trp Ile Pro Leu Val Met Lys Gln Cys
35 40 45
His Pro Asp Thr Lys Lys Phe Leu Cys Ser Leu Phe Ala Pro Val Cys
50 55 60
Leu Asp Asp Leu Asp Glu Thr Ile Gln Pro Cys His Ser Leu Cys Met
65 70 75 80
Gln Val Lys Asp Arg Cys Ala Pro Val Met Ser Ala Phe Gly Phe Pro
85 90 95
Trp Pro Asp Met Leu Glu Cys Asp Arg Phe Pro Gln Asp Asn Asp Leu
100 105 110
Cys
25
75
PRT
Artificial Sequence
Consensus sequence
25
Cys Pro Ile Ile Pro Leu Cys Ile Tyr Asn Thr Met Pro Asn Leu Leu
1 5 10 15
Gly His Gln Ala Gly Leu Glu Val His Gln Phe Pro Leu Val Cys Ser
20 25 30
Pro Leu Phe Phe Leu Cys Ser Met Tyr Ala Pro Cys Leu Pro Ile Pro
35 40 45
Pro Cys Arg Ser Leu Cys Glu Arg Ala Gly Cys Glu Pro Leu Met Phe
50 55 60
Gly Phe Trp Pro Glu Leu Cys Phe Pro Gly Cys
65 70 75
26
2124
DNA
Homo sapiens
26
gaattctcag gaattcgagg tagaaggtgg cagagagact tctgttcctg ggggccgagc 60
tgttgtgctg ataccgtcct cttggcgtct gccctagtgg ggacccttga ttttaacttg 120
aagttcctgg actgggtcta accttagcat gtgtgcctga gtgatggact tggtatttac 180
accagccacg ctgataagtg cacatgtgtt tttaatgttt tggctttcca caccacaaac 240
acacagatgt gctgtcgccc gggctaggac ttgagtaggg tttttctatt taaatatata 300
ttatatattt aaaaaagtgt cctcccagag ctaataccgt tgctagcagc tcttcctgcc 360
gccacaccgg gcaaagtcca cccactgccc cagtgttgag ggccaccatg ggcggcccca 420
cctggagagg tgctgctcac agcaaacagc tccaactgcg ccttcgcctc gccttccagg 480
gagcccagcc aggcccactg ggtatttaca agcagacctc cctcgcttca gccttcctga 540
acccctgtta gttgggaaac cacctgtctg caccgcagct agagaaccga ggagaggagc 600
cgctagtcta aagggctgtt ggttgaaatt aggaagcagt gtaaagaaaa agaaaaaaaa 660
agtttgggag gccaaggcag gagcatcacc tgaggtcagc agttcgagac cagcctggct 720
aacgtggtga aaccccgtct ctactaaaaa tacaaaaaat tagcgggggc gtggtggcac 780
gcggctgtaa tcccagctac tcgggaggct gaggcaggag aatggcttga acccgggagg 840
cggaggaagc agtcacggag atagcgccat tgcactccag cttaggcaac aagagagcga 900
aacttcgtca aaaaaaaaaa gtcttcataa tttcatgggt ttgcaagtat gatccaggct 960
ccccgcttct ctgcaagcca atgcgagtta attacagcgt ccgccctggt ctctctccac 1020
cccacgccgt gatccattcc ccttcttttt ctccccttgt cttttcctac tccccctttt 1080
atttatgtat ttttggtttt gttttttaag gggtgttgag ccgcgtctgg ttctagtaaa 1140
ccgaacccgc tcgcgaggga ggcgattggc tcccgcgccg gtgacggacg tggtaacgag 1200
tgcggctcgc cccgccggga gctgattggc tgcgcggggc ggctccgagg gctcggccgt 1260
aggagccccg cgcactccag ccctgcagcc tccggagtca gtgccgcgcg cccgccgccc 1320
cgcgccttcc tgctcgccgc acctccggga gccggggcgc acccagcccg cagcgccgcc 1380
tccccgcccg cgccgcctcc gaccgcaggc cgagggccgc cactggccgg ggggaccggg 1440
cagcagcttg cggccgcgga gccgggcaac gctggggact gcgccttttg tccccggagg 1500
tccctggaag tttgcggcag gacgcgcgcg gggaggcggc ggaggcagcc ccgacgtcgc 1560
ggagaacagg gcgcagagcc ggcatgggca tcgggcgcac ggaggggggc cgccgcgggg 1620
cagccctggg cgtgctgctg gcgctgggcg gcgcttctgg ccgtgggctc ggcagcgagt 1680
acgactacgt gagcttccag tcggacatcg gcccgtacca gagcgggcgc ttctacacca 1740
agccacctca gtgcgtggac atccccgcgg acctgcggct gtgccacaac gtgggctaca 1800
agaagatggt gctgcccaac ctgctggagc acgagaccat ggcggaggtg aagcagcagg 1860
ccagcagctg ggtgcccctg ctcaacaaga actgccacgc cgggcaccca ggtcttcctc 1920
tgctcgctct cgcgcccgtc tgcctggacc ggcccatcta cccgtgtcgc tggctctgcg 1980
aggccgtgcg cgactcgtgc gagccggtca tgcagttctt cggcttctac tggcccgaga 2040
tgcttaagtg tgacaagttc cccgaggggg acgtctgcat cgccatgacg ccgcccaatg 2100
ccaccgaagc ctccaagccc caag 2124
27
4500
DNA
Homo sapiens
27
ctcggccgta ggagccccgc gcactccagc cctgcagcct ccggagtcag tgccgcgcgc 60
ccgccgcccc gcgccttcct gctcgccgca cctccgggag ccggggcgca cccagcccgc 120
agcgccgcct ccccgcccgc gccgcctccg accgcaggcc gagggccgcc actggccggg 180
gggaccgggc agcagcttgc ggccgcggag ccgggcaacg ctggggactg cgccttttgt 240
ccccggaggt ccctggaagt ttgcggcagg acgcgcgcgg ggaggcggcg gaggcagccc 300
cgacgtcgcg gagaacaggg cgcagagccg gcatgggcat cgggcgcagc gaggggggcc 360
gccgcggggc agccctgggc gtgctgctgg cgctgggcgc ggcgcttctg gccgtgggct 420
cggccagcga gtacgactac gtgagcttcc agtcggacat cggcccgtac cagagcgggc 480
gcttctacac caagccacct cagtgcgtgg acatccccgc ggacctgcgg ctgtgccaca 540
acgtgggcta caagaagatg gtgctgccca acctgctgga gcacgagacc atggcggagg 600
tgaagcagca ggccagcagc tgggtgcccc tgctcaacaa gaactgccac gccggcaccc 660
aggtcttcct ctgctcgctc ttcgcgcccg tctgcctgga ccggcccatc tacccgtgtc 720
gctggctctg cgaggccgtg cgcgactcgt gcgagccggt catgcagttc ttcggcttct 780
actggcccga gatgcttaag tgtgacaagt tccccgaggg ggacgtctgc atcgccatga 840
cgccgcccaa tgccaccgaa gcctccaagc cccaaggcac aacggtgtgt cctccctgtg 900
acaacgagtt gaaatctgag gccatcattg aacatctctg tgccagcgag tttgcactga 960
ggatgaaaat aaaagaagtg aaaaaagaaa atggcgacaa gaagattgtc cccaagaaga 1020
agaagcccct gaagttgggg cccatcaaga agaaggacct gaagaagctt gtgctgtacc 1080
tgaagaatgg ggctgactgt ccctgccacc agctggacaa cctcagccac cacttcctca 1140
tcatgggccg caaggtgaag agccagtact tgctgacggc catccacaag tgggacaaga 1200
aaaacaagga gttcaaaaac ttcatgaaga aaatgaaaaa ccatgagtgc cccacctttc 1260
agtccgtgtt taagtgattc tcccgggggc agggtgggga gggagcctcg ggtggggtgg 1320
gagcgggggg gacagtgccc cgggaacccg gtgggtcaca cacacgcact gcgcctgtca 1380
gtagtggaca ttgtaatcca gtcggcttgt tcttgcagca ttcccgctcc cttccctcca 1440
tagccacgct ccaaacccca gggtagccat ggccgggtaa agcaagggcc atttagatta 1500
ggaaggtttt taagatccgc aatgtggagc agcagccact gcacaggagg aggtgacaaa 1560
ccatttccaa cagcaacaca gccactaaaa cacaaaaagg gggattgggc ggaaagtgag 1620
agccagcagc aaaaactaca ttttgcaact tgttggtgtg gatctattgg ctgatctatg 1680
cctttcaact agaaaattct aatgattggc aagtcacgtt gttttcaggt ccagagtagt 1740
ttctttctgt ctgctttaaa tggaaacaga ctcataccac acttacaatt aaggtcaagc 1800
ccagaaagtg ataagtgcag ggaggaaaag tgcaagtcca ttatgtaata gtgacagcaa 1860
agggaccagg ggagaggcat tgccttctct gcccacagtc tttccgtgtg attgtctttg 1920
aatctgaatc agccagtctc agatgcccca aagtttcggt tcctatgagc ccggggcatg 1980
atctgatccc caagacatgt ggaggggcag cctgtgcctg cctttgtgtc agaaaaagga 2040
aaccacagtg agcctgagag agacggcgat tttcgggctg agaaggcagt agttttcaaa 2100
acacatagtt aaaaaagaaa caaatgaaaa aaattttaga acagtccagc aaattgctag 2160
tcagggtgaa ttgtgaaatt gggtgaagag cttaggattc taatctcatg ttttttcctt 2220
ttcacatttt taaaagaaca atgacaaaca cccacttatt tttcaaggtt ttaaaacagt 2280
ctacattgag catttgaaag gtgtgctaga acaaggtctc ctgatccgtc cgaggctgct 2340
tcccagagga gcagctctcc ccaggcattt gccaagggag gcggatttcc ctggtagtgt 2400
agctgtgtgg ctttccttcc tgaagagtcc gtggttgccc tagaacctaa caccccctag 2460
caaaactcac agagctttcc gtttttttct ttcctgtaaa gaaacatttc ctttgaactt 2520
gattgcctat ggatcaaaga aattcagaac agcctgcctg tccccccgca ctttttacat 2580
atatttgttt catttctgca gatggaaagt tgacatgggt ggggtgtccc catccagcga 2640
gagagtttca aaagcaaaac atctctgcag tttttcccaa gtaccctgag atacttccca 2700
aagcccttat gtttaatcag cgatgtatat aagccagttc acttagacaa ctttaccctt 2760
cttgtccaat gtacaggaag tagttctaaa aaaaatgcat attaatttct tcccccaaag 2820
ccggattctt aattctctgc aacactttga ggacatttat gattgtccct ctgggccaat 2880
gcttataccc agtgaggatg ctgcagtgag gctgtaaagt ggccccctgc ggccctagcc 2940
tgacccggag aaaggatggt agattctgtt aactcttgaa gactccagta tgaaaatcag 3000
catgcccgcc tagttaccta ccggagagtt atcctgataa attaacctct cacagttagt 3060
gatcctgtcc ttttaacacc ttttttgtgg ggttctctct gacctttcat cgtaaagtgc 3120
tggggacctt aagtgatttg cctgtaattt tggatgatta aaaaatgtgt atatatatta 3180
gctaatcaga aatattctac ttctctgttg tcaaactgaa attcagagca agttcctgag 3240
tgcgtggatc tgggtcttag ttctggttga ttcactcaag agttcagtgc tcatacgtat 3300
ctgctcattt tgacaaagtg cctcatgcaa ccgggccctc tctctgcggc agagtcctta 3360
gtggaggggt ttacctggaa catagtagtt accacagaat acggaagagc aggtgactgt 3420
gctgtgcagc tctctaaatg ggaattctca ggtaggaagc aacagcttca gaaagagctc 3480
aaaataaatt ggaaatgtga atcgcagctg tgggttttac caccgtctgt ctcagagtcc 3540
caggaccttg agtgtcatta gttactttat tgaaggtttt agacccatag cagctttgtc 3600
tctgtcacat cagcaatttc agaaccaaaa gggaggctct ctgtaggcac agagctgcac 3660
tatcacgagc ctttgttttt ctccacaaag tatctaacaa aaccaatgtg cagactgatt 3720
ggcctggtca ttggtctccg agagaggagg tttgcctgtg atttcctaat tatcgctagg 3780
gccaaggtgg gatttgtaaa gctttacaat aatcattctg gatagagtcc tgggaggtcc 3840
ttggcagaac tcagttaaat ctttgaagaa tatttgtagt tatcttagaa gatagcatgg 3900
gaggtgagga ttccaaaaac attttatttt taaaatatcc tgtgtaacac ttggctcttg 3960
gtacctgtgg gttagcatca agttctcccc agggtagaat tcaatcagag ctccagtttg 4020
catttggatg tgtaaattac agtaatccca tttcccaaac ctaaaatctg tttttctcat 4080
cagactctga gtaactggtt gctgtgtcat aacttcatag atgcaggagg ctcaggtgat 4140
ctgtttgagg agagcaccct aggcagcctg cagggaataa catactggcc gttctgacct 4200
gttgccagca gatacacagg acatggatga aattcccgtt tcctctagtt tcttcctgta 4260
gtactcctct tttagatcct aagtctctta caaaagcttt gaatactgtg aaaatgtttt 4320
acattccatt tcatttgtgt tgttttttta actgcatttt accagatgtt ttgatgttat 4380
cgcttatgtt aatagtaatt cccgtacgtg ttcattttat tttcatgctt tttcagccat 4440
gtatcaatat tcacttgact aaagtcactc aattaatcaa taaaaaaaaa aaaaaaaaaa 4500 | The invention provides a novel, secreted protein that contains a region homologous to ligand binding domain of a cytokine receptor. This protein, called Frizzled-related protein (FRP), antagonizes the signaling of the Wnt family of cytokines. Extracellular signaling molecules such as the Wnt family members have essential roles as inducers of cellular proliferation, migration, differentiation, and tissue morphogenesis. As Wnt molecules are known to participate in the aberrant growth associated with neoplasia, Wnt antagonists such as FRP are valuable tools which both for understanding oncogenesis and for the design of new cancer therapies. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention relates to Provisional Application Serial Number 60/072,477, filed Jan. 26, 1998, by Sam Schwartz, and entitled “COSMETIC COMPOSITION”.
BACKGROUND OF THE INVENTION
[0002] This application is directed to an improved cosmetic and cleansing composition.
[0003] Modern environmental conditions, such as heating and air conditioning, dryness, exposure to the sun, and environment pollution exert severe stress on the skin and accelerate the skin deterioration. This can result in wrinkles, loss of firmness and elasticity, discoloration, dryness and other cosmetically undesirable effects. Additionally, medical conditions, such as psoriasis, can cause skin conditions which are exhibited as skin flaking and loss of skin tissue.
[0004] Although a number of cosmetic, cleansing and moisturizing compositions for use on the skin already exist, there is a need to provide a new cosmetic, cleansing and moisturizing composition which can provide advantages over those which are currently known. It is also desirable to have compositions for use not only on humans but also on animals, as well as compositions that can be used within the mouth as a cleanser of the mouth or the teeth.
[0005] Different compositions are known using mineral salts from the Dead Sea, for instance, as bath salts.
[0006] It is not, however, known to use such minerals for other cosmetic or cleansing purposes and for purposes of use in the mouth.
[0007] Compositions using mineral salts with an oily based carrier are known. They however have disadvantages when used as a scrub or exfoliating cleansing composition. Such scrub and exfoliating compositions would be particularly useful on human skin and tissue.
[0008] A need exists for a new cosmetic and tissue cleansing and moisturizing composition.
SUMMARY OF THE INVENTION
[0009] By this invention there is provided a cosmetic, cleansing and mouth formulations for use with human skin and on animal skin or tissue, which obviate the effect of modern environmental conditions on the human and animal body.
[0010] Some of these compositions include formulations suitable for entry into the mouth either as a dental toothpaste, cream or as a mouthwash.
[0011] An active ingredient of these compositions is a mineral salt, preferably Dead Sea salts.
[0012] The composition incorporates a new combination of ingredients particularly designed to provide protection from environmental pollution and to provide moisturization of the skin. The cosmetic composition provides for tissue repair and protection for conditions caused by psoriasis.
[0013] The cosmetic composition simultaneously provides moisturization and control of oil when necessary.
[0014] In general, the composition according to one other aspect the present invention comprises: water and, emulsified and dispersed in the water, minerals salts, preferably Dead Sea salts.
[0015] One composition of the invention includes the use of salts, preferably mineral salts and more preferably, Dead Sea mineral salt in conjunction with other components, such as a lotion, to create a cleansing composition for use as an exfoliating and scrubbing composition for the body or face tissue of a human or animal.
[0016] The composition is prepared with a water soluble and moisturizing lotion while retaining the effective action of the Dead Sea mineral salt, which is preferably granules, such granules normally being water soluble.
[0017] In a preferred form of the invention, the composition include a moisturizing and/or non-oily base element for retaining the Dead Sea mineral salt granules in their granule form until used so that the mixture will act as an exfoliating scrub.
[0018] The non-oily base is water soluble and thereby permits easy removal without leaving an oily film on the skin. The effect however is to provide for moisturizing the skin.
[0019] The preferred composition includes a lotion which includes D.I. water, Methylparaben, Propylene glycol, Glycerin 96%, Steareth-2 (Lipocol S-2), Steareth-20 (Lipocol S-20), Cetyl Alcohol (Lipocol C), Stearyl Alcohol (Lipocol S), Safflower oil, Isopropyl myristate (Liponate IPM), DC 200 Fluid 100 cst., Propylparaben, Germail II and Fragrance at a low ratio, approximately 1:10, or one part lotion to about ten parts, there is added Dead Sea mineral salts. A minimum active amount, preferably the least amount of water is used in the formulation of the composition so that as part of the lotion the salt granules are not inclined break down.
[0020] Other scrubbing agents such as silica or pumice can selectively be the effective scrubbing agent or can be added to the mineral salt composition. The product can contain other scrubbing agents such as loofah or nut shells. An antibacteria agent can also be incorporated in the formula.
DESCRIPTION
[0021] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims.
[0022] The ingredients of a preferred embodiment of the present invention, their proportions, and the sequences of which they are a part for the purposes of mixing are described.
[0023] A new combination of ingredients results in a skin composition that provides protection against many types of skin damage, particularly itching and psoriasis, as well as other types of skin damage that can occur. Such other conditions can be flaking, redness, eczema, rashes or dry skin. Moreover, the composition is useful for cleansing the skin tissue, hands and the body and can be an effective scrubbing and exfoliating composition.
[0024] The composition of the present invention comprises base in which cosmetic components are mineral salts, preferably Dead Sea mineral salts. Another additive which is useful against itching is eugenol extract, namely an extract of cloves, and this can be added to the composition as required.
[0025] Typically, the composition of the present invention further comprises ancillary components such as: (1) a lipid-soluble component; (2) an emulsifier component; (3) an antioxidant component; (4) a preservative component; (5) a solvent component; (6) a thickener component; (7) a hydrophilic component; and (8) fragrance.
[0026] The ingredients included within these components are described in detail below.
[0027] The ingredients are dispersed in an emulsified composition by the method of preparation described below. “Dispersed” refers to any process by which the ingredients are uniformly distributed in the emulsified base, and includes dissolving, emulsifying, and forming a colloidal suspension.
I. NATURE AND PROPORTION OF INGREDIENTS OF THE SKIN CREAM COMPOSITION
[0028] A. The Cosmetic Components
[0029] Each of the cosmetic components, particularly the Dead Sea mineral salts, contributes to the improved properties of the cosmetic and cleansing composition of the present invention is present in a quantity sufficient to increase the smoothness, decrease the lumpiness, or decrease the itchiness, or edema of skin to which the composition is applied. Moreover, it reduces itching and repairs skin, and act as a cleansing agent.
[0030] An essential ingredient of the invention are mineral salts such as Dead Sea salts. These Dead Sea salts are salts obtained from the region of Israel or Jordan known as the Dead Sea, and which contain at least the following active ingredients:
Magnesium Chloride (MgCl 2 ) 31.0-35.0% Potassium Chloride (Kcl) 24.0-26.0% Sodium Chloride (NaCl) 4.0-8.0% Calcium Chloride (CaCl 2 ) 0.4-0.6% Magnesium Bromide (MgBr 2 ) 0.3-0.6% Sulphates (SO 4 —) 0.05-0.2% Insolubles 0.05-0.3% Water of Crystallization 34.0-38.0%
[0031] B. The Ancillary Components
[0032] The composition of the present invention can further comprise a lipid-soluble component to provide added smoothness. The lipid-soluble component can comprise at least one ingredient selected from the group consisting of: (1) dimethicone; (2) bisabolol; (3) polyoxyethylene fatty acid esters; (4) cetyl alcohol; (5) a glyceryl triester of a medium-chain carboxylic acid selected from the group consisting of tricaproin, tricaprylin, tricaprin, and mixtures thereof; (6) white petrolatum; and (7) mineral oil.
[0033] The ancillary components, whose use is optional but preferable, impart additional desirable properties to the skin cream composition of the present invention. These components can include: (1) a lipid-soluble component; (2) an emulsifier component; (3) an antioxidant component; (4) a preservative component; (5) a solvent component; (6) a thickener component; (7) a hydrophilic component; and (8) fragrance. Preferably, the composition of the present invention comprises all the ancillary components as indicated below:
[0034] As comprised in a skin cream, the composition with the solvent provides for greater uniformity and ease of preparation. The solvent component can include one or two ingredients.
[0035] The thickener component improves the flow and Theological properties of the cosmetic composition. It permits the composition to be retained in a formulated state when applied to the skin. One or more ingredients can comprise the thickener component.
[0036] The hydrophilic component can comprise one or multiple ingredients.
[0037] If necessary, a preservative component can be used to retard microbial and mold growth in the composition. The preservative component can also act as a stabilizer.
[0038] The lipid-soluble component can also comprise one or multiple ingredients, and these can be varied depending upon the cosmetic composition as to be used. For instance, the composition can be formulated for normal skin, dry skin, or oily skin, and different lipid components can be used under those conditions.
[0039] 1. The Lipid-Soluble Component
[0040] The cosmetic composition can comprise the additional ancillary ingredients whose use is optional but preferable. These ancillary ingredients can include a solvent component, a preservative component, a thickener component, a hydrophilic component, a lipid-soluble component and a pigment. As necessary or suitable, a fragrant component can also be added. Various combinations of these ingredients can be used as the solvent, lipid, thickener or hydrophilic component.
[0041] The glyceryl triester of the medium-chain carboxylic acid can be tricaprylin. The lipid-soluble component comprises dimethicone, bisabolol, polyoxyethylene fatty acid esters, cetyl alcohol, tricaprylin, white petrolatum, and mineral oil.
[0042] The dimethicone can comprise about 0.75% of the composition, the bisabolol comprises about 0.1% of the composition, the polyoxyethylene fatty acid esters comprise about 2.5% of the composition, the cetyl alcohol comprises about 4% of the composition, the tricaprylin comprises about 7.5% of the composition, the white petrolatum comprises about 3% of the composition, and the mineral oil comprises about 6.0% of the composition.
[0043] 2. The Emulsifier Component
[0044] The skin cream composition of the present invention can further comprise an emulsifier component. Emulsifiers serve two functions. They act like a solubilizing agent to combine the water-soluble and non-water-soluble phases together; that is, to form a stable bridge between the waters and the oils of the ingredients. The emulsifiers also serve as emollients, providing a pleasant, esthetically appropriate tactile feeling when the emulsified composition is applied to the skin. The emulsifier component is present in a quantity sufficient to combine water-soluble and non-water-soluble phases of the composition.
[0045] The emulsifier component can comprise at least one of a mixture of mono- and distearate esters of polyoxyethylene and free polyethylene oxide, partial esters of lauric, palmitic, stearic, and oleic acids and hexitol anhydrides, and 120-mole ethoxylated jojoba oil. The emulsifier component can comprise a mixture of mono- and distearate esters of polyoxyethylene and free polyethylene oxide, partial esters of lauric, palmitic, stearic, and oleic acids and hexitol anhydrides and 120-mole ethoxylated jojoba oil. Preferably, the mixture of mono- and distearate esters of polyoxyethylene and free polyethylene oxide comprises about 1.25% of the composition, the partial esters of lauric, palmitic, stearic, and oleic acids and hexitol anhydrides comprise about 0.13% of the composition, and the 120-mole ethoxylated jojoba oil comprises about 1.0% of the composition.
[0046] 3. The Antioxidant Component
[0047] The composition according to the present invention can further comprise an antioxidant component. The antioxidant component prevents oxidation of the ingredients of the composition. The antioxidant component can be a mixture of 70% propylene glycol, 20% propyl gallate, and 10% citric acid. The antioxidant component comprises about 0.0011% of the composition.
[0048] 4. The Preservative Component
[0049] The skin cream composition according to the present invention can further comprise a preservative component. The preservative component is used to prevent the growth of microbes in the emulsified skin cream composition, which is typically manufactured under clean, but non-sterile conditions. The preservative component can comprise at least one of imidazolyl urea and a complex of propylene glycol, phenoxyethanol, chlorphenesin and methylparaben.
[0050] The preservative component can comprises both imidazolyl urea and a complex of propylene glycol, phenoxyethanol, chlorphenesin and methylparaben, the imidazolyl urea comprises about 0.0011% of the composition, and the complex of propylene glycol, phenoxyethanol, chlorphenesin and methylparaben comprises about 2.5% of the composition.
[0051] In the complex of propylene glycol, phenoxyethanol, chlorphenesin and methylparaben, the propylene glycol comprises from about 30% to about 45% of the complex, the phenoxyethanol comprises from about 22% to about 37% of the complex, the chlorphenesin comprises from about 11% to about 22% of the complex, and the methylparaben comprises from about 11% to about 22% of the complex.
[0052] 5. The Solvent Component
[0053] The composition according to the present invention can further comprise a solvent component. The use of a solvent component allows greater uniformity and ease of preparation. The solvent component can include at least one ingredient selected from the group consisting of ethylene glycol, propylene glycol, and 1,3-butylene glycol. The solvent component can comprise 1,3-butylene glycol and the solvent component comprises about 4.0% of the composition.
[0054] 6. The Thickener Component
[0055] The composition according to the present invention can comprise a thickener component in a quantity sufficient to retain the composition when it is applied to the skin of a wearer. The thickener component can comprise at least one ingredient selected from the group consisting of alginate derivatives and preneutralized carbomer 430. The skin cream composition can comprise both alginate derivatives and preneutralized carbomer 430. The alginate derivative can comprise about 0.2% of the composition, and the preneutralized carbomer 430 and be about 0.5% of the composition.
[0056] 7. The Hydrophilic Component
[0057] A composition according to the present invention can further comprise a hydrophilic component. The hydrophilic component can comprise a polar complex consisting essentially of mannitol, arginine, serine, pyrrolidone carboxylate, sucrose, citrulline, glycogen, histidine, alanine, threonine, glutamic acid, and lysine. The polar complex can comprise about 1.0% of the composition.
[0058] 8. Fragrance
[0059] The composition according to the present invention can further comprise fragrance. The use of fragrance is well known in the cosmetic art, and need not be described further. The fragrance can comprise about 0.45% of the composition, although this can vary depending upon the fragrance used.
[0060] Compositions according to the present invention can further comprise other components used in the cosmetic art, such as pigments and other conventional excipients. The use of such ingredients is well known in the cosmetic and cleansing art and need not be described further here. The pigment component gives the cosmetic composition an aesthetically desirable appearance and different pigments can be used as variables in relation to the skin tone of the intended user.
[0061] Other components of the composition which permit for its application to the skin include propylene, glycol, and effective amounts of aloe vera juice, sunflower oil, kessco OP, liponate, other hydrogenated vegetable oil, lipo GMS, stearic acid, and lipomulse.
[0062] As necessary, the product could also include, when intended for application to the skin, a suitable sunscreen composition. In different forms, although aloe vera juice is considered, other extracts are possible. This could, for instance, be extracts from other fruits such as balsalm or apricot.
[0063] An example of the cosmetic composition is set out as follows, together with the relative percentages of content, and also an indication of the relative phase of those products. The relationship of the phase is also set out in regard to the method of formulating the composition:
SAMPLE COMPOSITION FOR COSMETIC CLEANSING AND MOISTURIZING PRODUCT PHASE % MATERIAL 1 64.9500 DEIONIZED WATER 1.000 ALOE VERA JUICE 0.2000 METHYLPARABEN 2 3.0000 PROPYLENE GLYCOL 0.1000 KELTROLT 3 1.0000 SUNFLOWER OIL 2.0000 KESSCO OP 2.0000 LIPONATE GC 1.0000 THODORSIL 47V 350/SF 96-350 2.0000 HYDROGENATED VEGETABLE OIL 3.5000 LIPO GMS 470 - WITCONOL 2407 2.0000 STEARIC ACID 2.0000 LIPOMULSE 165/ARLACEL 165V 1.0000 LIPOCOL C/ALFOL 16 1.0000 LIPOWAX D 0.1000 PROPYLPARABEN 0.1000 VITAMIN E ACETATE 4. 0.5000 EUGENOL EXTRA USP 0.4000 MACKSTAT DM 0.0500 WHITE DIAMOND B/M63149 0.1000 COVIOX T70 5 10.0000 DEIONIZED WATER 5.0000 DEAD SEA SALT TOTAL 103.0000
[0064] The method of formulation of such a sample is as follows:
STEP TEMP 1 80° PHASE 1 Into a main SS compounding tank, meter Dionized Water. Add Aloe Vera. Turn on mixer. Begin heating to 80° C. 2 70° When the temperature of the main tank is at 70° C. sprinkle slowly Methylparaben. Mix well until completely dissolved. Recirculate batch to insure that no solid is left at the bottom. 3 RT PHASE 2 Into a suitably size container, add Phase 2 ingredients. Mix well into a uniform slurry. 4 80° When the temperature of the main tank is at 80° C. add slowly Phase 2 slurry. Note: Be sure to mix Phase 2 slurry well before adding to Phase 1. Keltrol T has a tendency to settle at the bottom. 5 80° PHASE 3 Into a separate ss auxiliary tank, add Phase 3 ingredient except Propylparaben. Begin heating to 80° CX. Turn on mixer when most of the waxes are melted. 6 70° When temperature of Phase 3 is at 70° C. sprinkle in slowly Propylparaben. Be sure to evacuate valve to insure that no solids are entrapped. 7 80° When the temperature of Phase 3 is at 80° C. and ready to be added to Phase 1, add Vitamin E Acetate. 8 80° EMULSIFICATION When both Phase 1 and Phase 3 reach 80° C., add Phase 3 to main batch. Mix well for 15 minutes. Recirculate batch on and off. 9 Begin cooling. 10 38° PHASE 4 When temperature of the main batch is at 38° C. add Phase 4 ingredients. Mix well. 11 RT PHASE 5 Into a suitably sized container add Phase 5 ingredients. Mix well until completely dissolved. 12 38° When the temperature of the main batch is 38° add the solution of Phase 5. Mix well. 13 30° Discontinue mixing and cooling at 30° C.
Sample Scrubbing or Exfollating Composition
[0065] Such a composition would include the following ingredients:
MATERIAL % D.I. water 75.28 Methylparaben 0.25 Propylene glycol 2.00 Glycerin 96% 5.00 Steareth 2 (Lipocol S-2) 1.00 Steareth-20 (Lipocol S-20) 2.00 Cetyl Alcohol (Lipocol C) 1.50 Stearyl alcohol (Lipocol S) 1.50 Safflower oil 4.00 Isopropyl myristate (Liponate IPM) 5.00 DC 200 Fluid 11 cst. 1.00 Propylparaben 0.07 Germail II 0.20 Fragrance 0.20
[0066] Additionally, there is Dead Sea salts added in a range of about 1:10, namely ten parts salt to one part of lotion. As needed, other scrubbing agents such as pumice or silica can be added.
[0067] Although the invention has been described with regard to a cosmetic product related to soothing the effects of psoriasis, there are other formulations of the product which essentially includes mineral salts, preferably Dead Sea salt which can be used for different purposes. As such, a mouthwash formulation can be provided. The product will assist in combatting bacteria and gum irritation and inflamation. The product can moisturize and assist in nourishment of the skin.
[0068] The Dead Sea salts can be formulated with an amount of water and a suitable fragrance for these purposes. Likewise, as a shampoo product, the formulation can be prepared for use on human hair as well as animal hair. An essential ingredient of such a product is also mineral salts, such as Dead Sea mineral salts, and the percentage of Dead Sea salt can vary according to the purpose and formulation.
CONDITIONING SHAMPOO COMPOSITION TSP % Masada salts 2.00 DI water 57.50 Cocomido propyl betaine/(Norfox) 7.00 SLES-2/(Norfox) (Sodium laureth sulfate) 20.00 SLES-60/(Norfox) 5.00 Cocomido propyl amine oxide/ 2.50 Schercamox CAA-G (Scher) Crodafos SG (Croda) 1.00 (PTG-5 Ceteth-10 phosphate) Oleamide DEA/Schercomid ODA (Scher) 2.50 Tritisol/sol wheat protein (Croda) 0.70 (Hydrolyzed wheat protein) Aloe 10:1 (D-D Chem) 0.20 Neutral henna 0.10 Algae extract 0.10 Comfrey leaf 0.10 Goldenscal root 0.10 Elderflower 0.10 Nettle 0.10 Rosemary 0.10 Red clover 0.10 panthenol (Roche) 0.10 DMDM hydantoin 0.40 Fragrance (Custom Essence) 0.30 CE-22601 coal tar mask TOTAL 100.00
[0069] The procedure for mixing the formulation is as follows:
[0070] 1. Add ingredients of phase A individually with mixing. Mix until homogeeous.
[0071] 2. When phase A is homogeneous, add individually ingredients of phase B.
[0072] Note: If scale up testing indicates that the fragrance is clouding the product, premix 1:1 with Triton X-100.
[0073] [0073] 3 . Adjust pH to around 6.
[0074] Further, the different compositions and formulations can also be used, for instance, in the soothing of the skin when subjected to acne.
[0075] The composition is applied to the skin to stop itching. When applied to animals particularly it is useful against skin disorders, and joint or arthritic problems. It is particularly useful on dogs and horses.
[0076] Other forms of the invention includes those when applied in liquid form. It can also be applied as saturated wipe or as a compress. Moreover, it is applicable as a scrubbing or exfoliating composition. Additionally, it can be formulated as an inhalant product where another component is eucalyptus.
[0077] A different composition of the formula can be used for inhaling to ease nasal or sinus congestion and to soothe coughing irritations due to bronchitis or similar conditions.
[0078] The invention has been described with regard to several examples which are for illustrative purposes only. | A cosmetic and tissue cleansing composition including mineral salts, preferably Dead Sea mineral salts as an effective agent to minimize the effect of itching on the skin from a condition caused by psoriasis. In another form, the composition can be used as an exfoliating or scrubbing composition. The composition being formulated with a non-oily base which is water soluble such that the granules which are mineral salts act as exfoliating or scrubbing agents. The composition can also be formed for dental or mouth use. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to a novel dihydroxy compound and a process for preparing the same.
Dihydroxy compounds have been widely used as a starting material for preparing various synthetic resins, such as polyarylate resin, polycarbonate resin, epoxy resin, polyester resin, etc. However, the resins obtained by using conventional dihydroxy compounds are not satisfactory in thermal and/or mechanical properties, and therefore it is desired to provide a dihydroxy compound capable of giving resins improved in these properties.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel dihydroxy compound useful as a starting material for preparing various resins and a process for preparing the compound.
A further object of the invention is to provide a novel dihydroxy compound capable of producing resins having improved thermal and/or mechanical properties and a process for preparing the compound.
These and other objects of the invention will become apparent from the following description.
The dihydroxy compound of the invention is 3,9-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane represented by the formula (I): ##STR2##
DETAILED DESCRIPTION OF THE INVENTION
The dihydroxy compound of the invention having the formula (I) is useful as a starting material for preparing various synthetic resins such as polyarylate resin, polycarbonate resin, epoxy resin, polyester resin, etc., and is capable of giving resins having improved thermal and/or mechanical properties.
The dihydroxy compound of the invention can be prepared preferably by subjecting to transesterification reaction 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane represented by the formula (II) ##STR3## and alkyl 4-hydroxybenzoate in the presence of a transesterification catalyst. The dihydroxy compound of the invention can be prepared also by a direct esterification process in which the compound of the formula (II) is esterified directly with 4-hydroxybenzoic acid in the presence of an acid catalyst such as sulfuric acid, paratoluenesulfonic acid, phosphoric acid, hydrochloric acid or the like. Among these methods the transesterification reaction is preferable in view of reaction velocity, and therefore the following description is made in reference to the transesterification reaction.
In carrying out the transesterification reaction of the present invention, it is preferable to use a specific transesterification catalyst selected from various transesterification catalysts. Preferable catalyst is at least one of organic tin compounds and inorganic tin compounds, which themselves are known as transesterification catalysts. Examples of organic tin compounds are tin oxalate, dibutyltin oxide, dibutyltin maleate, dibutyltin dichloride, tributyltin acetate, tributyltin chloride, trimethyltin chloride, etc. Examples of inorganic tin compounds are stannous oxide, stannic oxide, stannous chloride, etc. These catalysts can be used singly or in admixture with one another.
The amount of the catalyst to be used varies depending on the reaction temperature, but may usually be in the range of about 0.01 to about 10 mole %, preferably about 0.1 to about 5 mole %, based on the mole of 4-hydroxybenzoic acid ester.
Preferably exemplified as 4-hydroxybenzoic acid esters are lower alkyl 4-hydroxybenzoates, more preferably primary lower alkyl 4-hydroxybenzoates, such as methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, n-propyl 4-hydroxybenzoate, isopropyl 4-hydroxybenzoate, n-butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, etc. Secondary and tertiary alkyl esters having larger steric hindrance, although usable, are liable to retard the reaction.
The esters of 4-hydroxybenzoate can be used in an amount of about 2 to about 4 moles, preferably about 2 to about 2.5 moles, per mole of the 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane. With less than 2 moles of alkyl 4-hydroxybenzoate, a reduced yield of the desired compound results, whereas more than 4 moles of alkyl 4-hydroxybenzoate used increases the amount of the compound remaining unreacted, not only making the purification procedure complicated but rendering the process uneconomical.
The reaction can be carried out at a temperature of usually about 80 to 240° C, preferably at about 150 to 220° C. The reaction tends to be retarded at a temperature of lower than about 80° C, whereas the reaction temperature of higher than about 240° C is likely to cause undesired decomposition of the contemplated compound. The reaction time is usually about 2 to 48 hours, although suitably determinable in consideration of the reaction temperature and the amount of transesterification catalyst. The reaction is preferably carried out in the presence of an inert solvent such as benzene, toluene, xylene, cyclohexane, tetralin or the like.
The 3,9-bis[(1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane thus obtained can be used as it is or as purified by conventional method such as recrystallization or the like, depending on the application, utility, of the compound.
EXAMPLES
The present invention will be described in more detail with reference to the following examples.
EXAMPLE 1
In a reactor equipped with a stirrer, nitrogen-introducing tube, thermometer, separator and cooling tube were placed 608.3 g (2 moles) of 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 669.5 g (4.4 moles) of methyl 4-hydroxybenzoate, 9.92 g (0.04 mole) of dibutyltin oxide and 100 ml of xylene. The mixture was heated to 200° C while distilling off the xylene and kept with stirring at that temperature for 18 hours, giving 1,132 g of pale yellow semi-crystalline product. The crude product thus obtained was recrystallized from methylethyl ketone, giving 707 g of white crystal having a melting point of 236-239° C. Yield was 65%.
The crystal was identified as 3,9-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane by elementary analysis, IR absorption spectrum, 1 H-NMR spectrum and 13 C-NMR spectrum. Elementary analysis
______________________________________ C H______________________________________Calcd. 63.96% 6.66%Found 64.19% 6.79%______________________________________
ν max (KBr): 3285, 1680cm -1
1 H-NMR (DMSO-d 6 )
δppm: 0.95 (6H, s), 0.97 (6H, s), 3.36 (2H, d, J=12Hz), 3.59 (2H, d, J=12Hz), 3.61 (2H, d, J=llHz), 4.01 (4H, s), 4.29 (2H, d, J=llHz), 4.37 (2H, s), 6.84 (4H, d, J=9Hz), 7.82 (4H, d, J=9Hz), 10.63 (2H, s).
13 C-NMR (DMSO-d 6 )
δppm: 19.40 (q), 19.55 (q), 32.32 (s), 38.54 (s), 68.65 (t), 69.08 (t), 69.52 (t), 104.56 (d), 115.41 (d), 120.42 (s), 131.45 (d), 162.01 (s), 165.50 (s).
EXAMPLE 2
A 669 g quantity of white crystals was produced by following the same procedure as in Example 1 except that 5.39 g (0.04 mole) of stannous oxide was used in place of 9.92 g of dibutyltin oxide. Yield was 61.5%.
The obtained crystals were identical in melting point, IR spectra, 1 H-NMR spectra and 13 C-NMR spectra of the product with the 3,9-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane obtained in Example 1.
EXAMPLE 3
A 632 g quantity of white crystals was produced by following the same procedure as in Example 1 except that 13.31 g (0.04 mole) of tributyltin acetate was used in place of 9.92 g of dibutyltin oxide. Yield was 58.1%.
The obtained crystals were identical in melting point, IR spectra, 1H-NMR, 13C-NMR spectra with the 2,2-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane obtained in Example 1.
EXAMPLE 4
A 592 g quantity of white crystals was produced by following the same procedure as in Example 1 except that 7.58 g (0.04 mole) of stanous chloride was used in place of 9.92 g of dibutyltin oxide. Yield was 54.4%.
The obtained crystals were identical in melting point, IR spectra, lH-NMR, 13C-NMR spectra with the 2,2-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane obtained in Example 1.
EXAMPLE 5
A 685 g quantity of white crystals was produced by following the same procedure as in Example 1 except that 854.3 g (4.4 moles) of butyl 4-hydroxybenzoate was used in place of 669.5 g of methyl 4-hydroxybenzoate. Yield was 63.0%.
The obtained crystals were identical in melting point, IR spectra, lH-NMR, 13C-NMR spectra with the 2,2-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane obtained in Example 1.
EXAMPLE 6
A 668 g quantity of white crystals was produced by following the same procedure as in Example 1 except that 792.7 g (4.4 moles) of isopropyl 4-hydroxybenzoate was used in place of 669.5 g of methyl 4-hydroxybenzoate. Yield was 61.5%.
The obtained crystals were identical in melting point, IR spectra, lH-NMR, 13C-NMR spectra with the 2,2-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane obtained in Example 1. | This invention provides 3,9-bis[1,1-dimethyl-2-(4'-hydroxybenzoyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane represented by the formula: ##STR1## a process for preparing the above compound by a transesterification reaction of 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane with alkyl 4-hydroxybenzoate. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to DNA demethylation activity of DNA methyltransferases, therapeutic and diagnostic uses thereof.
BACKGROUND OF THE INVENTION
[0002] In vertebrates, DNA methylation occurs primarily at the 5-position of cytosine (C) in CpG dads and their genomic methylation patterns are established/maintained by the DNA (C-5)-methyltransferases, or DNMTs. Of the known vertebrate DNMTs, DNMT1 shows a substrates preference for hemi-methylated DNA and maintains the methylation patterns during, DNA replication. DNMT3A and DNMT3B show equal C-5 methylation activities toward unmethylated and hemi-methylated DNA in vitro, and they are essential for de novo genomic DNA methylation as well development of the early embryos. The vertebrate DNA methylation system comprising the above three essential DNMTs is indispensable for the establishment of the genomic DNA methylation patterns, globally and locally, and consequently the processes of gene expression, neuroplasticity, differentiation, carcinogenesis, imprinting, X-inactivation and development.
[0003] It has remained elusive in literature before 2012 whether there exists enzyme(s) in vertebrates that could actively and directly convert 5-mC on DNA into C.
SUMMARY OF THE INVENTION
[0004] In one aspect, the invention relates to a method for identifying a test agent (or a compound) as a modulator of the active DNA demethylation activity of a DNA methyltransferase. The method comprises:
[0005] a) providing a methylated DNA;
[0006] b) providing a DNA methyltransferase;
[0007] c) allowing the methylated DNA to react with the DNA methyltransferase for a sufficient time to perform a demethylation reaction and generate a demethylated DNA product in the presence or absence of a test agent;
[0008] d) analyzing the extent of demethylation; and
[0009] d) comparing the extents of the demethylation in the presence and absence of the test agent, and thereby identify the test agent as a modulator of the DNA demethylation activity of the DNA methyltransferase;
[0010] wherein the test agent is identified as an inhibitor of the active DNA demethylation activity of the DNA methyltransferase when the extent of the demethylation is less in the presence of the test agent; or the test agent is identified as a stimulator of the active DNA demethylation activity of the DNA methyltransferase when the extent of demethylation is more in the presence of the test agent
[0011] In one embodiment of the invention, the analyzing step is performed by a technique selected from the group consisting of a restriction digestion-polymer chain reaction (PCR) assay, a hydrolysis-thin layer chromatography assay, an antibody-based analysis, scintillation counting, autoradiography, dot blotting, a liquid chromatography-based analysis, and a Na bisulfite-based analysis.
[0012] In another embodiment of the invention, the demethylation reaction occurs in the presence of a calcium ion concentration of around 10 μM to 10 mM.
[0013] In another embodiment of the invention, the DNA methyltransferase is an isolated vertebrate DNA methyltransferase, or a recombinant DNA methyltransferase, or is present in a nuclear extract or is present in a cellular extract. The vertebrate DNA methyltransferase, the nuclear extract, or the cellular extract may he prepared from cells selected from the group consisting, of vertebrate cell cultures, vertebrate tissues, insect cells, worm cells, insect tissues, worm tissues, plant cells, plant tissues, yeast cells, and bacterial cells. The nuclear extract may be a sperm extract.
[0014] In another embodiment of the invention, the methylated DNA comprises a labeled methyl group. The methyl group in the methylated DNA may be radioactive-labeled.
[0015] In another embodiment of the invention, the aforementioned method steps (a) to (d) possess the following technical features: wherein:
[0016] (a) the methylated DNA provided in step (a) is a methylated reporter gene operably linked to a constitutive promoter and is present in a cell:
[0017] (b) the DNA methyltransferase provided in step (b) is operably linked to a constitutive promoter and is also present in the cell, or is endogenously present in the cell as an endogenous DNA methyltransferase;
[0018] (c) the demethylated DNA product generated in step (c) is a demethylated reporter gene, which expresses a reporter protein in the cell.
[0019] (d) the analyzing step is performed by a technique selected from the group consisting of:
(i) analyzing the signal of the reporter protein encoded by the demethylated reporter gene in the cell; (ii) analyzing the reporter protein expression by Western blot; and (iii) isolating the methylated and demethylated reporter gene and analyzing the extent of demethylation by a restriction digestion-polymer chain reaction (PCR) assay, a hydrolysis-thin layer chromatography assay, an antibody-based analysis, scintillation counting, autoradiography, dot blotting, a liquid chromatography-based analysis, or a Na bisulfite-based analysis.
[0023] In one embodiment of the invention, the methylated reporter gene and the DNA methyltransferase are present in the cell via transfection. Alternatively, the DNA methyltransferase is an endogenous enzyme present in the cell.
[0024] The cell is transfected with the methylated reporter gene, and the DNA methyltransferase may be an exogenouse enzyme transfected into the same cell, or may be an endogenous enzyme already present in the same cell. In one embodiment, the methylated reporter gene and the DNA methyltransferase are co-transfected into the cell.
[0025] In one embodiment of the invention, the test agent is introduced into the cell or added to a culture medium bathing the cell.
[0026] In another embodiment of the invention, the methylated reporter gene comprises a DNA sequence of a gene selected from the group consisting of a fluorescent protein-encoding gene, a luciferase gene, a drug-resistant gene, and genes of cell survivals.
[0027] In another embodiment of the invention, the methylated DNA comprises 5-methylcytosine (5mC)-containing DNA.
[0028] In another embodiment of the invention, step (c) is performed under a condition that is free of a reducing agent or under a non-reducing condition.
[0029] The DNA methyltransferase may be a modified form of a wild-type DNA methyltransferase, said modified form retaining the active DNA demethylation activity of the wild-type DNA methyltransferase.
[0030] The DNA methyltransferase may be selected from the group consisting of DNA methyltransferase 1, DNA methyltransferase 3A, DNA methyltransferase 3B, and any combination thereof.
[0031] The constitutive promoter may be, but not limited to, a cytomegalovirus promoter.
[0032] In another aspect, the invention relates to a method for identifying a test agent as a modulator of the active DNA demethylation activity of a DNA methyltransferase, in which the method comprises:
(I)
[0033] a) admixing a first composition comprising a methylated DNA with a second composition comprising the DNA methyltransferase in the presence or absence of a test agent;
[0034] b) allowing a demethylation reaction to occur by reacting the methylated DNA with the DNA methyltransferase for a sufficient time to generate a demethylated DNA product;
[0035] c) analyzing the extent of demethylation; and
[0036] d) comparing the extents of the demethylation in the presence and absence of the test agent, and thereby identify the test agent for modulating active DNA demethylation activity of the DNA methyltransferase;
[0037] wherein the test agent is identified as an inhibitor of the active DNA demethylation activity of the DNA methyltransferase when the extent of the demethylation is less in the presence of the test agent; or the test agent is identified as a stimulator of the active DNA demethylation activity of the DNA methyltransferase when the extent of demethylation is more in the presence of the test agent;
or (II)
[0038] 1) providing a cell culture medium containing cells transfected with a reporter gene that is methylated and operably linked to a constitutive promoter, said cells containing an endogenous DNA methyltransferase or exogenously expressing a wild-type, a modified or a genetically engineered DNA methyltransferase;
[0039] 2) exposing the cells to a test agent;
[0040] 3) allowing a demethylation reaction to occur to generate a demethylated reporter gene, which expresses a reporter protein in the cells; and
[0041] 4) analyzing the extent of demethylation of the reporter gene by examining the signal intensity of the reporter protein expressed by the demethylated reporter gene in the cells;
[0042] 5) comparing the extents of the demethylation of the reporter gene in the presence and absence of the test agent, and thereby identify the test agent as a modulator of the DNA demethylation activity of the DNA methyltransferase;
[0043] wherein the test agent is identified as an inhibitor of the active DNA demethylation activity of the DNA methyltransferase when the extent of the demethylation is less in the presence of the test agent; or the test agent is identified as a stimulator of the active DNA demethylation activity of the DNA methyltransferase when the extent of demethylation is more in the presence of the test agent.
[0044] The wild-type DNA methyltransferase may be selected from the group consisting of DNA methyltransferase 1, DNA methyltransferase 3A, and DNA methyltransferase 3B.
[0045] The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 shows DNA 5-mC demethylation activities of the mammalian DNMTs. The 5-mC-containing DNA substrates were subjected to incubation in 293T nuclear extracts in buffer B with 10 mM CaCl 2 that contained the exogenously expressed EGFP (lanes 1 and 2), mouse DNMT1 (lanes 3 and 4), DNMT3A (lanes 5 and 6), DNMT3B (lanes 7 and 8), and their site-directed mutants (lanes 9-14), respectively. The extents of conversion of 5-mC to C were analyzed by hydrolysis-TLC assay and quantitatively shown in the histogram. The amounts of the exogenous wild type enzyme in lanes 4, 6, and 8 were similar to those of the mutant enzymes in lanes 10, 12, and 14, respectively (Western blotting data not shown). M, mock control without incubation; R, with incubation. Error bars indicate S.D.*,p<0.05 by t-test comparing bars 4, 6, and 8 to bar 2.
[0047] FIG. 2A shows calcium-dependence of the DNA 5-mC demethylation activities of recombinant DNMTs. Hydrolysis-TLC assay of conversion of 5-mC to C by recombinant DNMT3B. The DNA demethylation activity of the recombinant mouse DNMT3B was assayed by incubation of 40 nM 5-mC containing DNA substrate with 40 nM of the enzyme in buffer B containing 100 μg/ml BSA and increasing concentrations (0, 10 μM, 100 μM, 1 mM, 5 mM and 10 mM) of CaCl 2 . The incubations were all at 37° C. for 4h. The quantitative results are presented in the histogram. M, mock control without incubation. Error bars indicate S.D.*,p<0.05;**,p<0.01 by t-test comparing bars 3-7 to bar 2.
[0048] FIG. 2B shows a comparison of the DNA demethylation activities of recombinant hDNMT1, hDNMT3A and DNMT3B by hydrolysis-TLC assay. The 5-mC containing substrate was incubated at 37° C. for 4h with 40 nM of each of the recombinant hDNMT1 (lane 2), hDNMT3A (lane 3) and DNMT3B (lane 4) in buffer B containing 100 μg/ml BSA arid 1 mM of CaCl 2 , and then analyzed by hydrolysis-TLC assay. The quantitative analysis is presented in the histogram. M, mock control without incubation; R, with incubation. Error bars indicate S.D.*,p<0.05;***, p<0.005 by t-test comparing bars 2-4 to bar 1.
[0049] FIGS. 3A-B show the effects of a reducing condition and SAM on the DNA demethylation and methylation activities of DNMT3B. FIG. 3A : The 5-mC containing DNA substrate was subjected to the demethylation reactions with 40 nM recombinant DNMT3B in buffer B containing 100 μg/ml BSA with or without the inclusion of 1 mM CaCl 2 , 5 mM DTT, or 160 μM SAM. After incubation at 37° C. for 4h, the DNA products were analyzed by the hydrolysis-TLC assay. The results are quantitatively presented in the histogram. Error bars indicate S.D.*,p<0.05 by t-test comparing bars 2-4 to bar 1. FIG. 3B : Unmethylated pMR1-8 plasmid DNA was incubated with 40 nM recombinant DNMT3B in buffer B containing 100 μg/ml BSA with or without 1 mM CaCl 2 , 5 mM DTT, or 160 μM SAM. After incubation at 37° C. for 4h, the extents of C methylation of the DNAs from the different reactions were determined by hydrolysis-TLC assay and quantitatively compared in the histogram. Error bars indicate S.D.
[0050] FlGS. 4 A-B show Reversibility of the DNA demethylation and methylation reactions in vitro, FIG. 4A : Strategy of a series of reactions testing the reversibility of DNA demethylation and methylation (see text for more details). Briefly, 5-mC containing DNA substrate was incubated at 37° C. for 2 h with 40 nM recombinant DNMT3B in buffer B containing 100 μg/ml BSA and 1 mM CaCl 2 (reaction 1). Then. 160 μM SAM were added and the incubation was continued for another 1 h (reaction 2). Finally, 1 mM H 2 O 2 was added to the reaction mixture and the incubation continued for another 2 h (reaction 3). Rx, reactions. FIG. 4B : The DNA products from the 3 reactions outlined in 4 A were purified and analyzed by hydrolysis-TLC assay. The data are quantitatively compared in the histogram. M, mock control without incubation. Error bars indicate S.D.*,p<0.05;***,p<0.005.
[0051] FIGS. 5A-B show Experimental strategies for assay of the inter-conversions of 5-mC and C. FIG. 5A : Schematic diagram illustrating the stepwise processes of restriction digestion-PCR assay. This assay was used to estimate the extents of demethylation of methylated plasmid upon incubation with the porcine sperm nuclear extract under different conditions ( FIG. 6 ). 20 ng of the 5-mC containing plasmid pMR1-8, with or without DNA demethylation reactions in the sperm nuclear extract, was digested byHpaII overnight at 37° C. and purified with Qiaquick Nucleotide Removal Kit (Qiagen). The proportion of HpaII-insensitive DNA substrate was analyzed by 12-15 cycles of PCR using a primer set bracketing the HpaII restriction cutting sites followed by the gel electrophoresis. The band intensities were further quantitatively estimated and compared. FIG. 5B : Schematic diagram illustrating the stepwise processes of hydrolysis-TLC assay. The double-stranded DNA substrates were digested by MspI at 37° C. overnight, and then dephosphorylated with calf intestine phosphatase. (New England Biolabs) followed by purification by Qiaquick Nucleotide Removal Kit (Qiagen). The purified DNAs were end-labeled by using γ 32 P-ATP and T4 polynucleotide kinase (New England Biolabs), and then digested by snake venom phosphodiesterase (Worthington) and DNasel (Roche) overnight. The hydrolyzates were loaded onto PEI cellulose plates (Merck) and separated in the buffer isobutyric acid: water: ammonia (66:18:3) for 16-18 h. Autoradiography of the plates was carried out and the signals on the plates were quantitated using the Alpha imaging 2200 (Alpha Innotech Crop.).
[0052] FIGS. 6A-C show the DNA demethylation activity of porcine sperm extracts. FIG. 6A : Fully methylated plasmid DNA pMRI-8 was incubated at 37° C. for 2 h in the porcine sperm nuclear extract: with increasing concentrations (0, 10 μM, 100 μM, 1 mM and 10 mM) of CaCl 2 (lanes 1-5), MgCl 2 (lanes 6-10) or Fe(NH 4 SO 4 ) 2 (lanes 11-15). After the reactions, the extent of DNA demethylation of the plasmid DNA was analyzed by the restriction digestion-PCR assay outlined in FIG. 5A . The histograms show the relative proportions of the plasmid DNA resistant to HpaII cleavage. For comparison of bars 2-5 to bar 1,*,p<0.05;**,p<0.01 by the t-test. FIG. 6B : Effects of BER inhibitors on the demethylation activities of the porcine sperm nuclear extract. The DNA demethylation reactions were carried out by incubating fully-methylated plasmid DNA pMR1-8 and sperm nuclear extract containing 10 mM CaCl 2 and increasing concentrations of APE-i (0, 10 μM 100 μM, and 1 mM, lanes 2-6) or 3-AB (0, 5 μM, 500 μM, 5 mM, and 50 mM, lanes 8-12). After the reactions, the extents of demethylation of the plasmid DNA were analyzed by the restriction digestion-PCR assay. FIG. 6C : Effect of the CDA inhibitor THU on the demethylation reaction in the porcine sperm nuclear extract. The fully-methylated pMR1-8 DNA was subjected to incubation in the extract at 37° C. for 2 h containing, increasing concentrations of THU (0, 30 μM, 100 μM and 1 mM, lanes 1-4). The extents of demethylation of the plasmid DNA were analyzed by the restriction digestion-PCR assay. The histogram shows the relative proportions of plasmid DNA resistant to HpaII cleavage. M, mock control without incubation. Error bars indicate S.D.
[0053] FIG. 7 shows the results of SDS-PAGE analyses. The recombinant human hDNMT1 (500 ng), human hDNMT3A (250 ng), and mouse DNMT3B (250 ng) were subjected to SDS-PAGE followed by the coomassie blue staining. The arrows indicate the expected bands of the three DNMTs, respectively. Protein markers were loaded in the M lanes.
[0054] FIG. 8 shows DNA demethylation by recombinant DNMT3B in the presence of 3 H-SAM. The reaction conditions were the same as those described in FIG. 3A , except that 1μCi 3 H-SAM was also included in each of the reaction mixtures. After the reactions, the mixtures were further incubated with 100 μl of 0.5N NaOH at 55° C. for 10 mins and neutralized with 100 μl of 1M Tris-Cl pH7.0. The DNA substrates were then precipitated with 10% trichloroacetic acid (TCA) in 5 mM Na pyrophosphate on ice for 15 mins, and loaded onto DE-81 ion-exchange papers followed by air drying. The DE-81 papers were washed 5 times with 5% TCA in 5 mM Na pyrophosphate, twice with 100% EtOH, air dried, and the 3 H counts on DNA were determined in a liquid scintillation counter.
DETAILED DESCRIPTION OF THE INVENTION
[0055] The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Various embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like components throughout the views. As used in the description herein and throughout the claims that follow, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Moreover, titles or subtitles may he used in the specification for the convenience of a reader, which shall have no influence on the scope of the present invention. Additionally, some terms used in this specification are more specifically defined below.
DEFINITIONS
[0056] The terms is used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the invention. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same thing can he said in more than one way. Consequently, alternative language and synonyms May be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to various embodiments given in this specification.
[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control.
[0058] As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent prefer ably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated.
[0059] The term “5mC” refers to the 5 position of cytosine.
[0060] The term “agent” refers to any matter, substance or thing producing or used for obtaining specific results, which includes, but not limited to, compounds, co-factors, etc.
[0061] The invention relates to the discovery that mammalian DNMTs, including DNMT1, DNMT3A, and DNMT3B can actively and directly convert 5-mC on DNA into C biochemical reaction. See Chen et al, (201.3) THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 288, NO. 13, pp. 9084-9091, which is incorporated herein by reference in its entirety.
[0062] Specifically, the invention relates to the discovery that in in vitro reactions, the mouse and/or human DNMT1, DNMT3A and DNMT3B all could act as an active DNA demethylase, removing the methyl group from 5-mC on DNA in an Ca 2+ ion and redox state-dependent manner.
[0063] The invention also relates to the discovery of the DNA 5-mC demethylation activities of DNMTs that could be used to screen, identity, and design reagents, including chemical compounds and therapeutic agents, which would modulate the DNA 5-mC demethylation activities of DNMTs and their modified forms/derivatives, for the purpose of regulating the different cellular processes including gene expression, chromosome structure, carcinogenesis (metastasis), cell division, cell motility, neuronal plasticity, etc.
[0064] The protein sequences of DNMTs are as follows: DNMT1 [ Homo sapiens ] SEQ ID NO: 4; DNMT1 [ Mus musculus ] SEQ ID NO: 5; DNMT3A [ Homo sapiens ] SEQ ID NO: 6; DNMT3A [ Mus musculus ] SEQ ID NO: 7; DNMT3B [ Homo sapiens ] SEQ ID NO: 8; DNMT3B [ Mus musculus ] SEQ ID NO: 9.
[0065] To generate modified DNMTs we serially deleted 10 amino acids from N-terminal of the full-length DNMTs. For example, the modified forms of human DNMT1 is DNMT1(11-1620), DNMT1(21-1620), DNMT1(31-1620) . . . , etc. All the deletion-modified DNMT1s are tested for DNA methylation and demethylation activities in vitro and in vivo. In addition, DNMT1 may be modified by deletion of the internal 10 amino acid of the full length DNMA1, and the modified forms are DNMT1(Δ11-20), DNMT1(Δ21-30). DNMT1(Δ31-40) . . . , etc. The same deletion modifications may be used to generate deletion modified forms of DNMT3A and DNMT3B.
[0066] To screen, identify, and/or design reagents that modulate the DNA 5-mC demethylation activities of DNMTs, several assays can be used, which include in vitro and in vivo assays.
[0000] (1) In vitro
[0067] The DNMTs and 5-mC containing DNA substrates are incubated with the test agents under proper reaction conditions. The DNMTs used may be in the forms of either recombinant wild-type/modified/genetically engineered enzymes or as ectopically expressed wild type/modified/genetically engineered enzymes in cellular or nuclear extracts prepared from vertebrate cell cultures/tissues, yeast cells, or bacterial cells. The methyl group on the 5-mC-containing DNA substrates can be radioactive, or labeled by other methods.
[0068] After the reaction, the DNA substrates are isolated manually or automatically, and the content of methylation/demethylation is determined by several methods, such as restriction digestion-based analysis, antibody-based analysis. Scintillation counting, autoradiography, dot blotting, liquid chromatography-based analysis. Na bisulfite-based analysis and hydrolysis-TLC (thin layer chromatography). The effect of each test agent on the DNA 5-mC demethylation activities of the DNMT enzymes is determined by comparison of the content of 5-mC on the DNA substrate with the control (mock), before and after the in vitro reaction.
[0000] (2) In vivo
[0069] The reporter DNAs methylated at 5-C are introduced into cells containing either the endogenous DNMTs alone or with exogenously expressed wild type/modified/genetically engineered DNMTs. The reagents to he tested are added into the cell culturing medium, or sent into the cells, before triggering the DNA demethylation activities of the DNMTs.
[0070] The methylated reporter DNAs carry genes, such as different fluorescence genes, luciferase gene, drug-resistant gene, or genes of cell survivals etc., the expression levels of which can indicate the methylation/demethylation status of the DNA substrates. Alternatively, the methylated report DNAs can be isolated manually or automatically, and analyzed with respect to their 5-mC content by methods described above.
EXAMPLES
Materials and Methods
[0071] Recombinant Plasmids and Recombinant Proteins. Constructions of expression plasmids used in this study were described in Chen et al. ( J Biol Chem. VOL. 287, pp. 33116-33121, 2012. It is incorporated herein by reference in its entirety), which included plasmids for exogenously expressing DNMT1, DNMT3A, and DNMT3B. The DNA methylation-inactive mutants of the DNMTs, i.e. DNMT1-PSC, DNMT3A-PS and DNMT3B-PS, were generated by insertion of a serine residue before the Cys-1229 at the catalytic site of DNMT1 or by replacing the cysteine residue Cys-706 and Cys-657 in the catalytic domains of DNMT3A and DNMT3B, respectively, with a serine residue.
[0072] All of the recombinant enzymes DNMTs, including hDNMT1 (purity ˜78%), hDNMT3A (purity ˜90%), and mouse DNMT3B (purity ˜50%) ( FIG. 7 ), were purchased from BPS Bioscience,
[0073] Cell Culture and DNA Transfection. The human embryonic kidney 293T cells were cultured under 5% CO 2 at 37° C. in DMEM medium supplemented with 10% FBS and 1% Penicillin-Streptomycin. For DNA transfections, different expression plasmids were delivered into cells using either LIPOFECTAMINE® 2000 or MAXIFECT™. The transfected cells were collected 2 days afterwards for further experimentation.
[0074] Preparation of Nuclear Extracts. The nuclear extracts were prepared from the porcine sperms and 293T cells, respectively, by a modified method. Briefly, The porcine semen was washed three times by PBS buffer and the sperm pellet isolated with FICOLL®. The pellet was resuspended in a hypotonic buffer (10mM Tris-HCl, pH7.4, 10 mM NaCl, 10 mM EDTA and EDTA-free protease inhibitors) on ice for 15 minutes. The resuspended sperms were passed through a G21 needle 10 times and then centrifuged at 13,200 rpm at 4° C. for 10 min. The supernatant was removed and the pellet of the nuclei was resuspended in a resuspension buffer (10 mM Tris-HCl, pH7.4, 10 mM NaCl, 1.5 mM, MgCl 2 and EDTA-free protease inhibitors), and an equal volume of 1M NaCl was added for 30 min incubation on ice. The solution was centrifuged at 13,200 rpm at 4° C. for 30 min and the supernatant (nuclear extract) was dialyzed at 4° C. in buffer B (10 mM Tris-HCl, pF7.4, 50 mM NaCl, 1.5 mM MgCl 2 and EDTA-free protease inhibitors) overnight with 2 changes of the dialysis buffer.
[0075] The preparation of nuclear extract from 293T cells followed the procedures described above. The transfected cells were washed 3 times with PBS and resuspended in the hypotonic buffer on ice for 10 mins. The solution was centrifuged at 4,000 rpm for 10 mins and the supernatant were removed. The nuclear pellet was resuspended in the resuspension buffer and then an equal volume of 1M NaCl was added for 30 min incubation on ice. The lysate was centrifuged at 13,200 rpm at 4° C. for 30 min and the supernatant was collected as a nuclear extract, which was then dialyzed at 4° C. in buffer B overnight.
[0076] DNA Substrates for in vitro DNA demethylation assay. The 5-mC-containing substrate for DNA demethylation assay of the porcine sperm nuclear extract was prepared from the 2,819 bp pMR1-8 plasmid containing 185 CpG dyads and 11 MspI restriction sites. The unmodified pMR1-8 plasmid was amplified in the SCS 110 bacteria and then methylated by the bacterial methyltransferase M.SSS I in NEB buffer 2 supplemented with 160 μM SAM (S-adenosylmethionine). The extent of methylation of the plasmid was checked by HpaII digestion.
[0077] C-5 methylated double-stranded DNA substrate was used in the demethylation reactions with 293T nuclear extract or the recombinant DNMTs (see below), and then analyzed by the hydrolysis-TLC assay.
[0078] In Vitro Reactions of 5-mC to C Conversion on DNA. For DNA demethylation reactions, 40 ng of the methylated pMR1-8 plasmid DNA or 5-mC containing double-stranded DNA substrate was incubated with 100 μg of the nuclear extracts or 40 nM recombinant DNMTs proteins in 50 μl of buffer B containing 100 μg/ml BSA at 37° C. up to 4 h. When needed, 10 μM-10 mM of three divalent cations (Ca 2+ , Mg 2+ , or Fe 2+ ), 10 uM-1 mM CRT0044876 (APE-i), 0.5 μM-50 mM 3-aminobenzamide (3-AB), 30 μM 1 mM tetrahydrouridine (THU), 5 mM DTT, or 160 μM SAM was included in the reaction mixtures. To assay the effect of redox-state of the enzymes, 40 nM recombinant DNMTs was pre-treated with 10 μM-10 mM H 2 O 2 in 50 μl of buffer B containing 100 μg/ml BSA at 15° C. for 30 min. Forty ng of the 5-mC containing double stranded DNA substrate was then added and the reaction mixtures were incubated at 37° C. for 4 h.
[0079] All reactions were stopped by 1.3% SDS and treated with proteinase K at 50° C. for 20 min. The DNA substrates and demethylated products at the end of the reaction were isolated using the Qiaquick Nucleotide Removal Kit, and subjected to restrictions digestion-PCR assay or hydrolysis-TLC assay (see below).
[0080] C-5 methylated double-stranded DNA substrate preparation. The 5-mC-containing DNA substrate was prepared by PCR amplification of a 561 bp fragment from the pMR1-8 plasmid containing MspI/HpaII sites (SEQ ID NO: 1). During the PCR amplification, a 5-mC-containing dNTP mix (Zymo Research) was used. Primers for PCR were: pMR1-8 F, 5′-aaagataccaggegtttcccc-3′ (SEQ ID NO: 2); and pMR1-8 R, 5′-gagttttcgttccactgagegtc-3′ (SEQ ID NO: 3).
[0081] In Vitro Reactions of C to 5-mC Conversion on DNA. Methylation in vitro of unmodified pMR1-8 plasmid DNA by the DNMTs were carried out and analyzed by the hydrolysis-TLC assay. When needed, 1 mM CaCl 2 or 5 mM DTT was also included in the reaction mixture.
[0082] Restriction Digestion-PCR Assay of (C-5 methylation on Double-Strand DNA Substrate(s). The procedures are as described previously (Chen et al., 2012, ibid). See FIG. 5A legend for more details.
[0083] Hydrolysis-TLC (Thin Layer Chromatography) assay of 5-mC, 5-hmC, and C on DNA. The procedures were similar to those described in Chen et al. (2012). ibid. See FIG. 5B legend for details.
Results
[0084] In vitro DNA demethylation by porcine sperm extract. We performed in vitro DNA C-5 demethylation reactions using the nuclear extract prepared from porcine sperms. The effect of Ca 2+ ion were also tested. Remarkably, inclusion of 1-10 mM of Ca 2+ , but not Mg 2+ (compare lanes 7-10 to lane 6) or Fe 2+ (compare lanes 12-15 to lane 11, FIG. 6A ), significantly reduced the extent of DNA methylation by 20-50% (compare lanes 4 and 5 to lane 1, FIG. 6A ). Furthermore, inclusion of inhibitors of either the BER pathway, CRT0044876 (APE-i) and 3-aminobenzamide (3-AB), or the cytidine-deaminase (CDA), tetrahydrouridine (THU), in the reactions had little effect on the in vitro DNA demethylation activity of the sperm nuclear extract ( FIGS. 6A and 6B ). The data of FIGS. 6A-B suggested that Ca 2+ ion stimulated a BER-independent and CDA-independent DNA demethylation activity in the nuclear extract of the porcine sperms.
[0085] It was not trivial to purify the factor(s)/enzyme(s) in the nuclear extract of the porcine sperms that was responsible for the in vitro conversion of 5-mC to C on DNA. Since the porcine sperm nuclear extract contained DNMT1/DNMT3A/DNMT3B (data not shown) and the murine/human orthologs of the latter two DNMTs acted in vitro as DNA 5-hydroxymethylcytosine (5-hmC) dehydroxymethylases under oxidative conditions in the absence of SAM, we suspected that under appropriate conditions, these DNMTs might also he capable to convert other modified forms of cytosine, e.g., 5-mC, to C.
[0086] In view of the data of FIG. 6 , we performed in vitro DNA demethylation reactions in the presence of 10 mM of Ca 2+ . 5-mC-containing double-stranded DNA substrate was incubated with nuclear extracts prepared from 293T cells transfected with plasmids overexpressing EGFP (a negative control), mouse DNMT1, mouse DNMT3A, mouse DNMT3B, as well as their mutants, respectively. After the reactions, the DNA products were hydrolyzed as depicted in FIG. 5B and the nucleotides were analyzed by TLC ( FIG. 1 ), As shown, under the reaction conditions tested, the nuclear extracts containing the exogenously expressed DNMT1 (lane 4, FIG. 1 ), DNMT3A (lane 6, FIG. 1 ), and DNMT3B (lanes 8, FIG. 1 ) all could remove the 5-methyl group from approximately 30% of the 5-mC residues on the DNA substrates.
[0087] Remarkably, the DNA demethylase activities of the 3 mouse DNMTs were greatly diminished, by approximately 73% to 88%, when amino acid substitutions or insertion were introduced into the known catalytic sites of C-5 methylation of these enzymes (compare lanes 10, 12, 14 to 4, 6, 8, respectively, FIG. 1 ), The data of FIG. 1 suggested that the two de novo DNMTs as well as the maintenance DNMT1 could act as active DNA 5-mC demethylases under appropriate conditions. The de novo DNMTs, DNMT3A and DNMT3B can transfer the methyl-group to DNA which do not contain any DNA methylation on both strands. After de novo methylation, the DNA is methylated on both DNA strands. The maintenance DNMT1 can methylate the hemi-methylated (one of double strands is methylated) DNA during the DNA replications.
[0088] Ca 2+ -and redox state-dependent DNA 5-mC demethylase activities of partially purified recombinant DNMTs. To further confirm the result of FIG. 1 , recombinant mouse DNMT3B, human DNMT1 (hDNMT1), and human DNMT3A (hDNMT3A) partially purified from recombinant baculovirus-infected Sf9 insect cells were examined for their DNA demethylation activities. First, the recombinant mouse DNMT3B (˜50% purity, FIG. 7 ) was subjected to incubation with 5-mC-containing DNA substrate in buffer B containing increasing concentrations (0, 10 μM, 100 μM, 1 mM, 5 mM and 10 mM) of CaCl 2 ( FIG. 2A ). As seen, the recombinant DNMT3B exhibited significant DNA demethylation activity only in the presence of Ca 2+ (compare lanes 3-7 to lane 2, FIG. 2A ), with the activity highest in the presence of 1 mM Ca 2+ (lane 5, FIG. 2A ). We tested and compared the DNA demethylation activities of DNMT3B, hDNMT1 (˜70% purity, FIG. 7 ) and hDNMT3A (˜90% purity, FIG. 7 ) in buffer B containing 1 mM CaCl 2 ( FIG. 2B ). Both hDNMT1 and DNMT3B exhibited high DNA demethylation activity, converting at least 50% of 5-mC on DNA to C (lanes 2 and 4, FIG. 2B ), while the recombinant hDNMT3A showed relatively lower activity (approximately 20% conversion, lane 3 of FIG. 2B ). Demethylation reaction by the recombinant mouse DNMT3B also removed the HpaII resistance of the methylated DNA substrate (data not shown). These data together demonstrated that mammalian DNMTs could function as active DNA demethylases in vitro.
[0089] The DNA demethylation activities of the DNMTs appeared to be affected by the redox state of the enzymes. As exemplified by DNMT3B, pre-incubation of the enzyme with the reducing dithiothreitol (DTT) greatly decreased the extent of conversion of 5-mC to C (compare lane 5 to lane 3. FIG. 3A ), although addition of H 2 O 2 as high as 10 mM to the reaction mixture did not affect the DNA demethylation activity of the enzyme (data not shown). In contrast to 5-mC demethylation, the 5-C methylation reaction of DNMTs did not require Ca 2+ , nor was it affected by DTT (compare lane 6 to lane 4, FIG. 3B ).
[0090] Reversibitily of the DNA 5-mC demethylation and 5-C methylation reactions catalyzed by DNMTs. As exemplified for DNMT3B in FIG. 3A , the inclusion of SAM, the methyl donors needed for DNA 5-C meths by the DNMTs, in the reaction mixture greatly reduced the extent of conversion of 5-mC to C (compare lanes 4 and 6 to lane 3 FIG. 3A ). This could be due to the inhibition of the demethylation activity of the DNMTs by SAM. Alternatively, the presence of SAM in the demethylation reaction might favor the methylation function of DNMTs, thus pushing the demethylation backwards. The latter scenario was confirmed with inclusion of radioactive 3 H-SAM in the reaction mixtures and quantitation of 3 H-labled-CH 3 on DNA after the reactions (lanes 4 and 6, FIG. 8 ). This result suggested that the DNA 5-mC demethylation reaction was reversible, with the presence SAM pushing the DNMT3B to re-methylate the demethylated cytosine on the DNA substrate.
[0091] The reversibility of the DNA methylation-demethylation reactions as catalyzed by the mammalian DNMTs was further studied by an analysis of the dynamic changes of the DNA methylation in vitro. In FIG. 4A , the double-stranded DNA substrate containing 5-mC was first incubated with the recombinant DNMT3B in a demethylation buffer for 2 h. SAM was then added and the incubation continued for 1 h. Finally, H 2 O 2 , which was known to inhibit the methylation reaction, was added and the reaction continued for another 2 h. As exemplified in the TLC plate and statistically presented in the histogram of FIG. 4B , approximately 60% of 5-mC on the DNA substrate were demethylated by DNMT3B at the end of the first reaction (compare lane 1/bar 1 to lane M/bar M, FIG. 4B ). The continued 1 h incubation in the presence of SAM converted more than 60% of the C back to 5-mC (compare lane 2/bar 2 to lane 1/bar 1, FIG. 4B ). Finally, the addition of H 2 O 2 led to the switch of the enzyme activity of DNMT3B from methylation to demethylation again (compare lane 3/bar 3 to lane 2/bar 2, FIG. 4B ), presumably due to loss the DNA methylation function of the oxidized enzyme. The data of FIGS. 3 and 4 altogether suggested that the switch of the catalytic functions of the DNMTs in between DNA methylation and demethylation was flexible, subjecting to the regulation by a range of factors including the local concentration of Ca 2+ , the presence of SAM, and the redox-state of the DNMTs.
[0092] Generation of Radioactive-labeled methylated DNA substrate. Two different methods were used to generate radioactive-labeled methylated DNA as follows: The unmethylated DNA is incubated with M.SSSI and radioactive SAM, such as 3 H-SAM or 14 C-SAM. After the incubation and DNA isolation, the radioactive signal of the DNA was determined by autoradiography or scintillation counting to quantitate methylated DNA. Optionally, the extent of the methylation of the DNA may be observed by HpaII digestion followed by gel electrophoresis. Alternatively, to make radioactive methylated DNA, PCR amplification is performed by using dNTP mix containing 5-[ 3 H]-methyl-dCTP or 5-[ 14 C]-methyl-dCTP. After purification of the PCR product, the extent of methylation of the DNA is analyzed by radioactive signal autoradiography or scintillation counting, and optionally observed the methylation level by HpaII digestion followed by gel electrophoresis.
[0093] Methylated reporter gene DNA substrate. A plasmid containing a reporter gene expressing a reporter protein such as EGFP or GFP (e.g., commercial available pEGFP-C1) was highly methylated by the enzyme M.SSSI in the presence of SAM using a method described above. Then the highly methylated and unmethylated reporter plasmids were transfected into 293T cell by Lipofectamine 2000 respectively. To detect expression of the reporter gene, the transfected cells were analyzed by a fluorescence microscopy and FACS flow cytometry. The results showed that the unmethylated EGFP reporter gene could strongly express the EGFP protein in the cells, but the highly methylated EGFP reporter gene expression of the EGFP protein was severely suppressed.
[0094] Based on the correlation between the DNA methylation level of the reporter gene and gene expression, we co-transfect the highly methylated reporter plasmid EGFP and the DNMTs-expression plasmids to 293 cells by Lipofectamine 2000. After 24 h, the transfected cells are treated with different test agents (chemical compounds) or different genetically modified viruses transduced with exogenous cDNA encoding a known protein of interest.
[0095] The cells co-transfected with methylated EGFP plasmids and DNMT3B-expression plasmid without any chemical or virus treatment showed 2-3 folds of EGFP-positive cell population comparing to the cells co-transfected with methylated EGFP plasmids and control plasmids (without DNMTs) without any chemical or virus treatment.
[0096] If the compound (test agent) or genetically modified virus could affect the DNA demethylation, the population of EGFP-positive cells will be changed. By comparing the EGFP-positive cell populations in the presence and absence of chemical (or virus) treatment, it is feasible to identify a compound (a test agent) which may enhance DNA demethylation (i.e., increasing GFP-positive cell population) or reduce the DNA demethylation (decreasing GFP-positive cell population).
[0097] In addition, the expression of reporter (EGFP) can be analyzed by western blotting.
[0098] The DNA methylation level of the reporter plasmids could also be determined by an in vitro method. After chemical or virus treatments, the methylated plasmids are isolated from the 293 cells. The DNA methylation level of isolated reporter plasmids can be determined by the several methods described above, such as a restriction digestion-polymer chain reaction (PCR) assay, a hydrolysis-thin layer chromatography assay, antibody-based analysis, scintillation counting, autoradiography, dot blotting, liquid chromatography-based analysis, Na bisulfite-based analysis.
[0099] Other candidate genes for reporters may be used, for example: (1) Neomycin-resistance gene, which can keep the cell survive under Neomycin (G418) treatment; (2) Puromycin resistance gene. The cell with expression of this gene can survive under Puromycin treatment: (3) Blasticidin resistance gene, which can make cell survive under Blastindin selection; (4) Luciferase gene—pGL3 reporter vector (Promega). The firefly ( Photinus pyralis ) luciferase can catalyze the two-step oxidation reaction to yield light (550-570 nm); (5) Red Fluorescence gene-pDsRed-C1. The protein is red fluorescence protein (excitation-557 nm, emission-592 nm); and (6) Green fluorescent protein (GFP)-encoding gene.
[0100] Antibody-based analysis. DNAs with different methylation levels are immunoprecipitated by the 5-mC antibody. The precipitated DNA may be analyzed by PCR or pyro-sequencing to determine the relative methylation level.
[0101] Dot blotting. DNAs with different methylation levels are loaded onto NC membranes in serial diluted amounts and cross-linked by UV. The membranes are hybridized with 5-mC antibody and exposed with X-Ray films. The strong dot signal indicates a strong methylation level on the DNA.
[0102] Scantillation counting, autoradiography. A Scintillation counter is a common-used instrument that can mesure ionizing radiation. A radioactive-labelled DNA, such as 3 H or 14 C methylated DNA, is load into a container containing a scintillation cocktail. The radioactive signal is determined with a Scintillation counter by detection of light emssion. In addition, radioactive-labelled DNA may be load into a gel or on a NC membrane, and exposed with an X-Ray film.
[0103] Liquid chromatography-based analysis. The affinity of each deoxynuclesides (dC, dmC, dT, dG, and dA) to bind a C18 column is different. In this assay, DNA is degradated by DNasel and Nuclease P1 to generate deoxynucleasides. The degradated mixture is subjexted to an HPLC system with a C-18 column. After injection of the mixture, deoxynucleasides are eluted individually at different time points by a hydrophilic buffer.
[0104] Na bisulfite-based analysis. DNAs with different methylation levels are treated with Na-bisulfite. The unmethylated cytosine is deaminated to uracil, but not the methylated DNA. The bisulfite treated DNAs are further amplified by PCR and sequenced by cloning. In the final sequence result, the original un-methylated cytosine will present “T”, and the original methylated cytosine will present “C”. Based on this bisulfite-generated polymorphisms, the DNA methylation level can be analyzed by sequencing, PCR amplification with site-specific primers, HRM (high resolution melt), restriction digestion (COBRA), non-denaturing gel(MS-SSCA), or MALDI-TOF.
[0105] The current study has revealed a totally unexpected characteristic of mammalian DNMTs, likely those of the vertebrates in general. That is, the vertebrate DNMTs, in addition to converting C to 5-mC on DNA, can also actively demethylate 5-mC on DNA under specific conditions ( FIGS. 1 and 2 ), in particular in the presence of Ca 2+ ion and under non-reducing condition ( FIG. 3 ). in other words, the covalent addition of the methyl group to the C-5 position of cytosine on DNA, as catalyzed by DNMTs, is reversible ( FIG. 4 ), The loss of the DNA demethylation activities of the mutant forms in comparison to the wild type enzymes ( FIG. 1 ) also suggests that each of the 3 DNMTs utilizes the same domain or overlapping domains to catalytically methylate and demethylate DNA.
[0106] Based on our data presented above, in particular the Ca 2+ dependence of the DNA demethylation activities of the 3 DNMTs and in the porcine sperm nuclear extract, we suggest that in addition to other pathways, e.g. the conversion of 5-mC to 5-hmC by TET and 5-hmC to C by DNMT3A and DNMT3B, direct conversion of 5-mC to C by the active DNA demethylation activities of the 3 DNMTs also play a major role in the genome-wide demethylation during early embryonic development of the vertebrates.
[0107] In summary, we have discovered that the mammalian DNMT1, DNMT3A, and DNMT3B, contrary to the conventional thought of their being mainly DNA methyltransferases, also act in vitro as active DNA demethylases in a Ca 2+ ion- and redox state-dependent manner. | Methods for identifying a test agent as a modulator of the active DNA demethylation activity of a DNA methyltransferase are disclosed. The method comprises: a) providing a methylated DNA; b) providing the DNA methyltransferase; c) allowing the methylated DNA to react with the DNA methyltransferase for a sufficient time to perform a demethylation reaction and generate a demethylated DNA product in the presence or absence of a test agent; d) analyzing the extent of demethylation; and d) comparing the extents of the demethylation in the presence and absence of the test agent, and thereby identify the test agent as a modulator of the DNA demethylation activity of the DNA methyltransferase. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S. provisional patent application Ser. No. 61/987,895, titled “SYSTEMS AND METHODS FOR FORMING REULEAUX SHAPES,” filed May 2, 2014, and incorporates this application by reference.
BACKGROUND
[0002] Polygons of constant width and height, with an odd number of sides greater than or equal to three, also known as Reuleaux polygons (named after Franz Reuleaux, a German engineer who lived from 1829-1905), have unusual and useful properties which would be understood to one of skill in the art. For example, manhole covers are almost always round, because if they were any other common shape such as a rectangle, a triangle, or an oval, having one side smaller than the other means they would easily fall into their own manhole during installation or if dislodge by a passing vehicle. Reuleaux polygon shapes, such as a Reuleaux triangle, or pentagon, improve on the circle; not only will they not fall into a corresponding manhole, but they will also not roll away almost indefinitely as a circular-shaped manhole cover would. Reuleaux-shaped manhole covers, unlike circle-shaped manhole covers, also will not rotate when installed, so that warnings, text or images written thereon will stay oriented the same way as when they were installed. Further, and importantly as security is a growing concern for large public events such as marathons, Reuleaux-shaped manhole covers are difficult to counterfeit or tamper with, especially when welded shut.
[0003] Because of their beneficial properties, Reuleaux shapes have also been used for coins in certain countries, especially in the Commonwealth of England, and most often as Reuleaux heptagons. They are difficult to counterfeit, and due to their constant width, roll easily in vending machines. Reuleaux shapes have also been used in pencils and drill bit inserts.
[0004] Reuleaux shapes also have a constant height as they are rolled along a flat surface, and thus a flat object, such as a ruler laid atop one or more identical rolling Reuleaux shapes will translate horizontally but not vertically. The center of the Reuleaux shape will, however, move up and down.
[0005] Reuleaux shapes can be made by subtractive manufacturing, that is, using equipment such as saws, drills, milling machines, lathes and CNC machines to take away extra material from a larger object until it is in a Reuleaux shape. The extra material that was purchased becomes waste, and has to be discarded or recycled at an additional cost.
[0006] Reuleaux shapes can also be made by additive manufacturing, where parts are assembled, welded, glued or bolted on. However, this is ineffective particularly for certain material that will not fuse with separately created-pieces of like material (such as ceramics and certain plastics including polypropylene).
[0007] Reuleaux shapes can also be made by casting or 3D printing, but these are expensive options.
[0008] Accordingly, it would be advantageous for there to be systems and methods for generating Reuleaux shapes, without the need for specialized molds, machining, carving, stamping, or tooling, all of which would add to the manufacturing cost.
BRIEF DESCRIPTION OF THE INVENTION
[0009] In one embodiment, of the present invention, there is a method of forming a Reuleaux shape from a material including placing the material into a container, moving the container along an orbit a plurality of times until the motion of the container along the orbit causes the material to assume a Reuleaux shape, and removing the Reuleaux shape from the container. The Reuleaux shape may be a Reuleaux triangle. The container may be a quadrilateral. The Reuleaux shape may be a Reuleaux pentagon, and the container may be a hexagon. The material may be a paste-like substance. Between one quarter of a cup and three quarters of a cup of the material may be used. The material may comprise sand and silicone, and it may comprise approximately 98% sand and approximately 2% silicone. The material may be kept at a humidity between 40% and 70%. The material may weigh between 30 and 52 grams. The material may be formed into a circular or near-circular disc shape before the motion of the container along the orbit causes the material to assume the Reuleaux shape.
[0010] The moving of the container may involve translation but not rotation of the container. The moving of the container may be performed for between 30 seconds and 10 minutes. A track may be used to guide the moving of the container. A vertical rod, or a small shape from 2 cm to 7 cm in diameter, may be used to guide the moving of the container. The orbit is circular, square, in the shape of a square with rounded corners, or of a circle with compressed sides, elliptical or oval, The orbit may be a first ellipse or oval and a second ellipse or oval stacked, the first ellipse or oval being elongated front to back, and the second ellipse or oval being elongated right to left. The orbit may be concave. The orbit may be along a horizontal plane or surface. The moving of the container may occur both clockwise and counter-clockwise. The container may have interior dimensions approximately 9.5 cm by 9.5 cm. The orbit may have a diameter and the container may have an interior width such that the diameter of the orbit is between one and two times the interior width of the container. The motion of the container may be mechanized. The Reuleaux shape may be frozen and then baked.
[0011] The baking may occur at between 250 and 290 degrees for between 180 and 300 minutes. The Reuleaux shape may have a maximum thickness that is approximately 20% of its width. The container may be plastic, polypropylene or polycarbonate. The container may have a top, and it may have a bottom. The container may have knoblike feet on the bottom. The container may have no bottom. There may be a plurality of breaks during the moving of the container, and the method may further involve flattening the material during at least one of the plurality of breaks, and flipping the material over during at least one other of the plurality of breaks. The container may be mounted on a platter that is mounted on a wheel, and the platter and the wheel may be used in the moving of the container. The material may be pre-treated by heating it at between 70 and 130 degrees Celsius for between 5 and IS minutes. The container may be a cube-shaped container, and the Reuleaux shape may be a three-dimensional Reuleaux shape. During the moving of the cube-shaped container, the cube-shaped container may be positioned in multiple different orientations, such that at least three faces of the cube-shaped container are faced upwards.
[0012] In another embodiment of the present invention, a device for transforming material into a Reuleaux shape includes a wheel, a platter mounted on the wheel, and a container mounted on the platter. The container may be removably mounted on the platter by a mount. The mount may be size-adjustable to receive containers of different sizes. The platter may have one or more handles. The wheel may have ball bearings.
[0013] In yet another embodiment of the present invention, there is a kit for forming a Reuleaux pentagon, including a material comprising sand and silicone and a hexagonal container. The material may comprise approximately 98% sand and approximately 2% silicone.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a Reuleaux triangle made according to one embodiment of the present invention.
[0015] FIGS. 2 A- 2 PPP show a method for making a Reuleaux triangle according to an embodiment of the present invention.
[0016] FIGS. 3A and 3B show top and bottom views of a platter and a Reuleaux triangle according to one embodiment of the present invention.
[0017] FIG. 4 shows the results of baking a Reuleaux triangle formed according to embodiments of the present invention.
[0018] FIGS. 5A-5H shows various views of two 3-dimensional Reuleaux shapes made according to another embodiment of the present invention, with FIGS. 5A-5E showing a first 3-dimensional Reuleaux shape and FIGS. 5F-5H showing a second 3-dimensional Reuleaux shape.
[0019] FIGS. 6A-6C show various views of an approximately cubic container which may be used to create a 3-dimensional Reuleaux shape, as shown in FIGS. 5A-5H .
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of the present invention solve the problems discussed in the Background section through the use of a different manufacturing process that is neither additive, subtractive, or based on casting. Rather, in embodiments of the present invention, movement is harnessed to shape material into a Reuleaux shape 11 . As will be understood by one of skill in the art, no manufacturing method results in geometrically perfect shapes, and accordingly terms Reuleaux shape, Reuleaux polygon, Reuleaux triangle, Reuleaux pentagon, etc., when applied to physical objects, refers to an approximation of a geometrically perfect version of the named Reuleaux shape, as will be understood by one of ordinary skill in the art based on acceptable manufacturing tolerances and the images presented in this application.
[0021] In embodiments of the invention, a material 10 is used that will ultimately become the Reuleaux shape 11 (such as is shown in FIG. 1 ), as well as a holding container 20 . The material 10 may be a paste-like substance, and about a half-cup of the material 10 may be used may be used, as shown in the Figures. A different amount of material 10 may be used, for example, from one quarter to three quarters of a cup, depending on the size of Reuleaux shape 11 desired and the holding container 20 selected. Depending on the fluidity of the material, it may be moved into the holding container 20 with a tool such as a spoon, or by hand, or poured directly into the holding container 20 . The holding container 20 , and therefore also the material 10 , are subjected to a series of movements. In certain embodiments, these movements are applied for a time period between less than a minute and several minutes. For example, the movements in some embodiments may be applied for 30 seconds, 45 seconds, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes or 10 minutes, or any range between these various times. As a result of these movements, the material 10 forms a Reuleaux polygon 11 .
[0022] In certain embodiments, the material 10 becomes a Reuleaux triangle 11 . In certain other embodiments, it becomes a Reuleaux pentagon. In some embodiments, the thickness of the Reuleaux polygon 11 formed is less than its width. The maximum thickness may be approximately 20% of the width. The ratio of thickness to width is dependent on the particular material used, the speed of the movement, the sequence of movement orbits, and other factors including humidity.
[0023] A large rectangular or square tray, with slightly raised sides, such as used in a cafeteria, can be used to create a Reuleaux shape 11 according to embodiments of the invention. For example, a 14″×20″ tray can be used. Other flat surfaces 21 can also be used, as will be understood by one of skill in the art.
[0024] A container 20 , such as a square plastic container for forming a three-sided Reuleaux 11 —that is, a “Reuleaux triangle” 11 ) can be used. However, in another embodiment, a container 20 having a slippery, hard, smooth bottom surface is used. The container 20 can be made of polypropylene according to an embodiment. However, in another embodiment, the container 20 is made of polycarbonate. In yet another embodiment, the polycarbonate is clear polycarbonate. In certain embodiments, small knoblike feet on the bottom of the container are used to reduce friction. The container 20 may have a top or not have a top. The container 20 may have a bottom or not have a bottom (in which latter case it is analogous in shape to a section of a pipe).
[0025] In an embodiment, the material 10 is formed from a mixture of sand and silicone. The sand may be high grade sand. The proportions may be approximately 98% sand or high grade sand and approximately 2% silicone. Small amounts of other ingredients may be used, including Polydimethylsiloxane (PDMS), which gives the material enhanced flow properties, and/or boric acid, which helps the material bind together. The raw material may be kept at room temperature. The raw material 10 may be kept at a medium humidity. In one embodiment, the humidity is between 40% and 70%. In certain embodiments, WABA Fun, LLC's Kinetic Sand product may be used, which is 98% pure sand. However, in other embodiments, compounds and materials having similar properties can be used, as will be understood by one of skill in the art. For example, the materials substituted for Kinetic Sand as discussed at http://www.chemicalforums.com/index.php?topic=70895.0 and http://www.chemicalforums.com/index.php?topic=70895.15 may be used.
[0026] Measuring tools, such as a ruler, caliper, and precision scale (such as a digital scale with a tare function) may also be used in confirming the attributes of the raw materials, equipment, and resulting Reuleaux shape.
[0027] In embodiments of the present invention, applying certain types of motion to a portion of the appropriate raw material 10 , placed in a suitable container 20 , results in the formation of a three-sided Reuleaux shape 11 .
[0028] In certain embodiments, the raw material 10 is initially formed into a circular or near-circular “patty” shape (analogous to the shape of a hamburger patty).
[0029] According to certain embodiments of the present invention, no mold, machining, carving, stamping, or tooling is, or need be, employed.
[0030] According to embodiments of the invention, the tray is on a horizontal plane or surface. In alternate embodiments, no tray is used, and the container 20 is placed directly on a horizontal plane or surface 21 .
[0031] FIGS. 2 A- 2 PPP show a method for making a Reuleaux triangle 11 according to an embodiment of the present invention, with the various figures being taken at approximately one second intervals. First the 98% high quality sand and 2% silicone raw material 10 are formed into an approximately circular “patty” shape, by forming the material 10 into an approximately spherical shape and then flattening it into a patty. Then the container 20 is rotated around an orbit, for example, approximately six times. Then the raw material 10 is flattened more. Then the container 20 is rotated, for example approximately twenty-three more times. Then the raw material 10 is flattened more, and then flipped over, and then flattened more. Then the container 20 is rotated, for example approximately twenty-five more times. Then the raw material 10 is flipped over. Then the container 20 is rotated, for example approximately thirteen more times. Then the raw material 10 is flipped over. Then the container 20 is rotated, for example approximately fifteen more times. Then the raw material 10 is flipped over. The result is a Reuleaux triangle 11 . The numbers of rotations recited above are merely illustrative and a person of ordinary skill in the art would understand that different numbers may be used to achieve the same results.
[0032] In certain embodiments, including the one shown in top and bottom view in FIG. 3A and FIG. 3B , respectively, a platter 30 is mounted on a wheel 31 . The platter may be large, and it may be rigid. The wheel may be ball-bearing 32 like, and it may be able to rotate in any direction. It may do so without favoring either direction. A mount 34 may be affixed to the platter. The mount 34 may be adjustable, and it may be able to receive different size containers 20 . Handles 33 may be added. The wheel 31 is used to spin the platter 30 and container 20 , which container 20 contains the material 10 . This may be done on a flat surface 21 . The flat surface 21 may be a workbench, an extremely flat sheet of Corian, a concrete floor, or another flat surface as will be understood to one of ordinary skill in the art.
[0033] Adjustments to these embodiments may be made when they are being operated by different operators. Different shapes of track may be attached to the workbench. These shapes may be circles, squares, or squares with rounded corners, all of different widths. The track may guide the orbits of the movement. A vertical rod may be attached to the platter 30 or to the wheel 31 , to allow the track to guide the movement of the platter 30 .
[0034] In another embodiment, a cup-like attachment is mounted under the platter 30 or wheel 31 . A vertical rod may be attached to the table, and may be used to guide the movement. Or, in addition to or in place of the vertical rod, any of various shapes may be used to guide this cup-like attachment. These various shapes may be cut from plywood. The plywood may be a 1″ sheet of plywood. These various shapes may be squares, discs, or ovals, or other shapes capable of guiding the orbit. These various shapes may be small. They may range from 2 cm to 7 cm in diameter.
[0035] The container 20 , or the platter 30 , is slid over the tray or plane 21 . The orbit of the sliding motion may approximate a chosen shape. The shape may be circular, or a square. In an embodiment, the orbit is a hybrid shape that is generally square but with rounded edges. In another embodiment, the orbit is close to a circle, but with compressed sides. The compressed sides may be located on one or more or all of the following sides: left, right, top, and bottom. In further embodiments, the orbit may be of any shape represented along the continuum of a square morphing into a circle as the rounded corners get larger and larger.
[0036] In certain embodiments, the orbit can be an ellipse or an oval. In other embodiments, it may be two ellipses stacked (that is, put together), or two ovals stacked, each one very close to a circle, one being elongated front to back, and the other elongated right to left. The orbit may be concave.
[0037] In various embodiments, the orbit is in a horizontal plane. For example, all of the above-described orbits may be in a horizontal plane.
[0038] In certain embodiments, the container is translated but moved without rotation. The container may be slid alternating between clockwise and counterclockwise.
[0039] In this two-dimensional plane, the translation may go right to left and left to right, back to front and front to back. Thus, in certain embodiments, the container 20 , and the raw material 10 , are not experiencing any rotation. Stated differently, the angle of rotation of the container 20 and its contents in such embodiments is zero degrees.
[0040] To visualize this, consider a Ferris wheel. The X axis goes left to right, the Y axis goes up and down, and the Z axis goes front to back. In its usual, vertical position, there is no movement in the Z axis. The wheel and all the spokes experience a 360 degree rotation in the X/Y plane. The baskets only experience a translation in the X/Y plane, without a rotation. While all their points go through a change of their X/Y coordinates, their relative position remains the same. Thus the highest part of the basket remains in the top-most relative position, with the same applying to the bottom-most, left-most and right-most points, and more generally to all the points.
[0041] Now let us flip the Ferris wheel 90 degrees back. It is now flat in the X/Z plane. There is no movement in the Y axis. The wheel and the spokes experience a rotation in the X/Z plane. But the baskets do not rotate, and only experiences a translation in the X/Z plane, left to right, and front to back
[0042] And analogous to any basket of the Ferris wheel, the container 20 , in certain embodiments of the invention, experiences a horizontal rotation of zero degrees, and two types of translations (front-back and left-right).
[0043] In an alternate embodiment, a container without a bottom is instead rotated in the vertical plane.
[0044] The shape of the container 20 which can generate, and has generated, a three-sided Reuleaux 11 according to an embodiment of the invention is a quadrilateral. This three-sided Reuleaux may be in the shape of a tube with a Reuleaux section, rather than a disk. In a further embodiment the container shape is a rectangle. In a further embodiment it is a square.
[0045] The shape of the container which can generate, and has generated, a five-sided Reuleaux according to a different embodiment of the invention is a six-sided container (a Hexagon). In certain embodiments, the hexagon is a regular hexagon.
[0046] The shape of the container 20 which can generate an n-sided Reuleaux (where n is any odd counting number greater than or equal to three, for example, three, five, seven, nine, eleven, thirteen, fifteen, and so on . . . ) according to further embodiments of the invention is an (n+1)-sided container (an even number, for example, four, six, eight, ten, twelve, fourteen, sixteen, and so on . . . ). In certain of these embodiments, the (n+1)-sided container is a container in the shape of a regular (n+1)-sided polygon.
[0047] In certain embodiments, the success rate of forming Reuleaux shapes, and in particular Reuleaux triangles, and the speed of forming such shapes is increased by selecting an ideal quantity of raw material for a given size of container. These metrics can also be increased by selecting a container that is not too large, and not too small. In one embodiment, the container is approximately 10 cm square and 5 cm high, with interior dimensions approximately 9.5 cm by 9.5 cm, and the amount of material is approximately a half-cup, or between a quarter of a cup and three quarters of a cup.
[0048] The amount of raw material 10 used affects the thickness and/or size of the Reuleaux shape, as can the speed of the rotation employed. If an excess of material is used, a disk may be produced rather than a Reuleaux shape.
[0049] In certain embodiments, the closeness of the initial raw material shape used to a perfectly circular “patty” is determined by the number of sides to the Reuleaux shape intended to be created. Thus, when creating a Reuleaux triangle 11 , the initial raw material shape used may not be of great importance, and, in certain embodiments, need not closely approximate a circular patty. However, when creating a Reuleaux shape with more sides, the initial raw material shape used may more closely approximate a perfectly circular “patty”. Using such a shape for the initial raw material 10 may help in the creation of the many-sided Reuleaux, as Reuleaux shapes with more sides will more closely approximate a circle.
[0050] In some embodiments, the diameter of the orbit of the container 20 is selected to be approximately, or just a bit less than, two times the width of the container 20 . In certain embodiments, this diameter of the orbit of the container is selected to be between one and two times the width of the container. In some embodiments, the speed of the rotation is selected such that it is fast enough for a Reuleaux shape 11 to form. In some embodiments, the sharpness of the outline of the Reuleaux shape 11 is increased by increasing the speed of the rotation of the container 20 . In some embodiments, the rotation of the container is mechanized, using such mechanisms as are known in the art.
[0051] Preferred weights of raw material 10 , which give rise to particular curve widths and thickness/heights for the resulting Reuleaux triangle 11 can be derived from the below testing chart, by one of skill in the art, it being understood that the container used was 10 cm square and 5 cm high, with interior dimensions of 9.5 cm×9.5 cm, and that sample number 5 resulted in the best shape:
[0000]
Sample no.
weight
curve width*
thickness/height
1
86 g
5
cm
2.5
cm
2
70 g
4.5
cm
2
cm
3
60 g
4.5
cm
1.75
cm
4
52 g
4
cm
2
cm
5
40 g
4
cm
1.5
cm
6
30 g
3.75
cm
1.2
cm
*the Reuleaux triangle resembles an equilateral triangle shaped balloon that has been overinflated.
[0052] The altitude of an equilateral triangle is the line that starts at one tip, and bisects the opposite side at a 90 degree angle. Such a triangle with 3×10 cm sides has an altitude “A”=S×(√3)/2 or 10×0.866=8.66 cm.
[0053] A remarkable characteristic of a Reuleaux triangle is that the Altitude is equal to the side. “A”=“S”. In this example, “S”=“A”=10 cm.
[0054] After the Reuleaux shape is formed it may be removed from the container.
[0055] In a further embodiment, for hardening and preservation purposes, after the Reuleaux polygon 11 is formed from the material 10 , the Reuleaux polygon 11 may be frozen, and then baked. The freezing may occur for 48 hours, or for at least 48 hours. Where smaller amounts of material are being frozen, the freezing may occur for a shorter period of time. The baking may occur in a toaster oven, or in any other device capable of providing high levels of heat for a long period of time. The temperature may be at approximately 270 degrees Celsius. The time may be approximately four hours. However, other temperatures may be used, for example, 250-290 degrees Celsius. Other times may be used, for example, three to five hours. Baking a single Reuleaux shape alone may be performed, so as to provide a uniform temperature all around the Reuleaux shape. Baking for a longer period of time may result in the color of the material becoming a dark grey, giving it a burned look. The baking temperature, for additional precision, may be measured using such more precise temperature-measuring devices as are known to those of ordinary skill in the art, such as the temperature-measuring devices manufactured by Raytech. Baking may result in the burning off, or conversion to a non-active form, of PDMS, in the event that is in the material. As shown in FIG. 4 , the results of freezing and then baking (right) are far superior to baking alone (left). In an embodiment, the particular material 10 used in the freezing and baking process is formed from a mixture of sand and silicone. In a further embodiment, the sand may be high grade sand. In yet a further embodiment the proportions may be approximately 98% sand or high grade sand and approximately 2% silicone. In a further embodiment, the raw material may be kept at room temperature prior to freezing. In yet a further embodiment, the raw material may be kept at a medium humidity prior to freezing. In one embodiment, the humidity is between 40% and 70%. In certain embodiments, the freezing and banking process is applied to WABA Fun, LLC's Kinetic Sand product, or another material which is 98% pure sand.
[0056] In another embodiment of the present invention, materials as described in the preceding paragraph, for hardening and preservation purposes, may be frozen, and then baked, regardless of its precise shape.
[0057] In another embodiment, the shape of these materials, whether or not in a Reuleaux shape, may be preserved by freezing (as described above), and then coating with polyurethane. The polyurethane may be applied as a spray. Alternately, after freezing, a mixture of wood glue and water can be applied. Alternately, after freezing, a very fluid type of epoxy, sufficient to infuse through the voids between sand particles in the material, may be used. For example, cyanoacrylates, which are used in such products as KRAZY GLUE® brand adhesives, may be used.
[0058] In a further embodiment of the present invention, pre-treating of the material, prior to the moving of the container, may occur. For example, the material pre-treating may involve heating the material at a low temperature, for example approximately 100 degrees Celsius (or between 70 and 130 degrees Celsius, for a short period of time, for example approximately 10 minutes (or between 5 and 15 minutes).
[0059] 3-dimensional Reuleaux shapes 41 may also be formed according to embodiments of the present invention. An approximately cube-shaped container 50 , such as is shown in FIGS. 6A-6C may be used. The cube-shaped container 50 may have rounded corners. All of the edges of the cube-shaped container 50 should have approximately equal length. To ensure a standardized cube is used, the faces of the cube-shaped container 50 may be numbered so that the sum of the marks of two parallel sides that face one another equals 7, in the manner of a standard six-sided die. The cube-shaped container 50 , containing material 1 as described above, is sequentially slid in a rotary orbit a plurality of times (for example, 5-10 times) in multiple different orientations. In one embodiment, there are three such orientations, namely, with each of three faces of the cube-shaped container 50 having a shared vertex facing up. By analogy to a standard six-sided die, these orientations are as if the sliding occurred with the “1” facing up, then with the “2” facing up, then with the “3” facing up. This process may be repeated multiple times. This may result in a three-dimensional Reuleaux shape 41 (appearing somewhat similar in shape to a tetrahedron), as shown in FIGS. 5A-5H . The cube-shaped container may be approximately 8 inches on a side, or may have about 500 cubic centimeters of volume. The amount of material used may be about 40-55 cubic centimeters, or about 35-60 cubic centimeters.
[0060] While the invention has been described by way of example and in terms of particular embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | Methods for forming a Reuleaux shape from a material involving placing the material into a container, moving the container along an orbit until the motion of the container along the orbit causes the material to assume a Reuleaux shape, and removing the Reuleaux shape from the container. Devices for transforming material into a Reuleaux shape, including a wheel, a platter mounted on the wheel, and a container mounted on the platter. Kits for forming a Reuleaux pentagon, including material having sand and silicone and a hexagonal container. | 0 |
BACKGROUND
Applicants' invention relates to methods and apparatuses for receiving electromagnetic signals, and more particularly to coherent receivers in digital communication systems.
Digital communication systems include time-division multiple access (TDMA) systems, such as cellular radio telephone systems that comply with the GSM and TIA-136 telecommunication standards and their enhancements like GSM/EDGE, and code-division multiple access (CDMA) systems, such as cellular radio telephone systems that comply with the IS-95, cdma2000, and WCDMA telecommunication standards. Digital communication systems also include “blended” TDMA and CDMA systems, such as cellular radio telephone systems that comply with the UMTS telecommunication standard. This application focusses on CDMA systems for simplicity, but it will be understood that the principles described in this application can be implemented in TDMA and other digital communication systems.
In a CDMA communication system, an information data stream representing, for example, speech to be transmitted, is impressed upon a higher-rate data stream that may be called a “signature sequence” or a “spreading sequence”. Typically, the signature sequence is a binary bit stream that can be replicated by an intended receiver. The information data stream and the signature sequence stream are combined by multiplying the two bit streams together, assuming the binary values of the two bit streams are represented by +1 or −1. This combination of a higher-bit-rate signature sequence with a lower-bit-rate data stream is called “spreading” the lower-bit-rate data stream. It will be understood that information data streams may be encoded for error correction and other reasons and may be combined with other binary sequences that have useful cross—and auto-correlation properties, e.g., Walsh-Hadamard sequences, before the resulting combinations are spread.
A plurality of spread information streams can modulate a radio-frequency (RF) carrier, for example by phase shift keying (PSK), and then be jointly received as a composite signal at a receiver. Each of the spread information signals overlaps all of the other spread signals, as well as noise-related signals, in both frequency and time. The spread information signals can be isolated by correlating the composite signal with the signature sequence, and then the information signals can be reconstituted by decoding appropriately.
Among other things, a coherent receiver in a digital communication system estimates the impulse response of the communication channel through which signals pass from the transmitter to the receiver to optimize its performance. The channel is typically modelled as a tapped delay line, in which the tap locations correspond to signal ray, or path, time delays and the generally complex tap coefficients correspond to channel coefficients. The result of the channel estimation process is a set of estimates of the tap locations and coefficients that is provided to a signal demodulator. The set of estimates is usually obtained through some combination of coherent and non-coherent values that are produced by correlating the received signal with a predetermined training sequence, in TDMA systems, or with a signature sequence, in CDMA systems. For TDMA and other narrowband communication systems, the demodulator is usually a coherent detector, such as a DFE or MLSE equalizer. For CDMA and other wideband communication systems, the demodulator is usually a RAKE receiver.
This sort of receiver is used in many digital communication systems because transmitted signals are reflected by objects, like buildings and mountains, between the transmitter and receiver. Thus, a transmitted signal propagates to the receiver along not one but many paths so that the receiver hears many echoes, or rays, having different and randomly varying delays and amplitudes. In a CDMA communication system, the receiver receives multiple versions of the transmitted composite signal that have propagated along different paths, some of which may have relative time delays of less than one chip. As a result of such time dispersion and in the absence of a RAKE receiver, correlating the received signal with a signature sequence would produce an output having several smaller spikes rather than one large spike. The several spikes are combined in an appropriate way by the RAKE receiver, which is so named because it “rakes” all the multipath contributions together.
FIG. 1 is a block diagram of a typical coherent receiver 1 for a CDMA-type digital communication system. A carrier removal block 100 depicts components used for receiving a modulated carrier signal and extracting the modulation from the carrier, which is a process of signal down-conversion from the spectral region of the carrier to the spectral region of the modulation, usually base band. The modulation, or base-band spread signal, is provided to a delay selector block 101 that determines a set of estimates of tap locations and coefficients, i.e., a set of delays, for the different signal echoes received. This set of estimates is provided to a propagation channel estimator block 102 as described above. The delays can be determined by correlating the received signal with a known portion of the transmitted signal, such as pilot symbols or training sequences, over a pre-defined time window, and selecting from the correlation values based on received power or signal-to-interference ratio (SIR). The pilot or training symbols are used in estimating the impulse response of the propagation channel in block 102 as described.
Many devices and methods for determining and selecting echoes may be used. For example, use of complex delay profiles, which can be averaged to form a power delay profile, is described in U.S. patent application Ser. No. 09/005,580 filed on Jan. 12, 1998, by E. Sourour et al. for “Method and Apparatus for Multipath Delay Estimation for Direct Sequence Spread Spectrum Communication Systems”. Other devices and methods for determining and selecting echoes are described in U.S. patent application Ser. No. 10/017,745 filed on Dec. 14, 2001, by E. Sourour et al. for “Interference Suppression in a Radio Receiver”; and U.S. Provisional Patent Applications No. 60/412,321 filed on Sep. 23, 2002, by X. Wang et al. for “Efficient Multipath Detections” and No. 60/412,899 filed on Sep. 23, 2002, by E. Jonsson for “Objective Multi-path Delay Selection Algorithm for WCDMA”.
The base-band spread signal is also provided to a RAKE block 103 that includes a number of “fingers”, or de-spreaders, that are each assigned to respective ones of the selected echoes. Of course, it will be appreciated that the RAKE block could include one finger that is re-used for each selected echo if the block operates fast enough. Each finger combines an echo selected by block 101 with the spreading sequence so as to de-spread the received composite signal. The RAKE block 103 typically de-spreads both sent information data and pilot or training symbols that are included in the composite signal. It will be appreciated that one or more fingers of the RAKE receiver block can be used in the delay selection block 101 to determine the echo delays that are selected. Such fingers are sometimes called “path searchers”.
Various aspects of RAKE receivers are described in G. Turin, “Introduction to Spread-Spectrum Antimultipath Techniques and Their Application to Urban Digital Radio”, Proc. IEEE, vol. 68, pp. 328–353 (March 1980); U.S. Pat. No. 5,305,349 to Dent for “Quantized Coherent Rake Receiver”; U.S. Patent Application Publication No. 2001/0028677 by Wang et al. for “Apparatus and Methods for Finger Delay Selection in Rake Receivers”; U.S. patent applications Ser. No. 09/165,647 filed on Oct. 2, 1998, by G. Bottomley for “Method and Apparatus for Interference Cancellation in a Rake Receiver” and Ser. No. 09/344,898 filed on Jun. 25, 1999, by Wang et al. for “Multi-Stage Rake Combining Methods and Apparatus”.
In a combiner block 104 , de-spread information data is multiplied by the complex conjugates of respective propagation channel estimates to remove distortion introduced by the propagation channel. The products are summed over the selected number of delays and fed to a decoder and de-interleaver block 105 , which may include a Viterbi decoder or a Turbo decoder, for example. The block 105 produces decoded symbols that replicate the transmitted information data.
For a digital receiver implemented in one or more integrated circuits, the decoder and de-interleaver can require a large area of silicon, and it is therefore desirable to keep the number of bits used to represent numbers in this block as low as possible. If the delays provided from the RAKE block 103 to the combiner 104 are highly correlated, then the combiner adds, in effect, the same signal twice. This can cause serious loss of soft information due to overflow after truncating the outputs of the combiner due to the limited number of bits in the decoder. Besides the absence of true diversity combining and its benefits, this results in deteriorated decoding performance, particularly when the delay selector 101 chooses multiple delays that all originate from the same path. This is likely when the selector's delay resolution is less than one chip and is due to temporal broadening of the echoes by pulse shaping of the transmitted signal.
SUMMARY
Applicants have recognized that these and other problems can be solved by selectively scaling the delays used in the combiner to retain soft information, regardless of the degree of correlation of the delays. This results in improved decoder performance.
In one aspect of Applicants' invention, a method of scaling path delay values in a communication system, in which estimates of received symbols corresponding to the path delays are combined, includes the step of determining a respective weight value for each path delay based on relative correlations of the path delays. The weight values may be determined by getting a plurality of path delay values; identifying the path delay values as either peak values or neighbor values; organizing the peak values and neighbor values into groups, with each group including at least one peak value and at least one neighbor value; for each group, determining a set of weight values; and checking the groups for duplicated path delay values and selecting a weight value from the weight values determined for the duplicated path delay values as either one of the weight values for the duplicated path delay values or a combination of the weight values for the duplicated path delay values.
In another aspect of Applicants' invention, a receiver for signals transmitted in a digital communication system, the signals including transmitted symbols, includes a delay selector that determines sets of path delays for received signal echoes; a propagation channel estimator that determines estimates of an impulse response of a channel through which the transmitted signals have propagated; a demodulator that determines estimates of the transmitted symbols; a propagation channel weights computer that determines weight values for path delays determined by the delay selector based on relative correlations of the path delays; and a combiner that combines the estimates of the impulse response, the estimates of the transmitted symbols, and the weight values, wherein the weight values scale the estimates for the combiner.
The propagation channel weights computer may determine weight values for path delays by identifying the path delays as either peaks or neighbors; organizing the peak and neighbors into groups, with each group including at least one peak and at least one neighbor; determining a set of weight values for each group; and checking the groups for duplicated path delays and selecting a weight value from the weight values determined for the duplicated path delays as either one of the weight values for the duplicated path delays or a combination of the weight values for the duplicated path delays.
In another aspect of Applicants' invention, a computer-readable medium contains a computer program for scaling path delay values in a communication system in which estimates of received symbols corresponding to the path delays are combined. The computer program performs the step of determining a respective weight value for each path delay based on relative correlations of the path delays. The weight values may be determined by at least the steps of getting a plurality of path delay values; identifying the path delay values as either peak values or neighbor values; organizing the peak values and neighbor values into groups, with each group including at least one peak value and at least one neighbor value; for each group, determining a set of weight values; and checking the groups for duplicated path delay values and selecting a weight value from the weight values determined for the duplicated path delay values as either one of the weight values for the duplicated path delay values or a combination of the weight values for the duplicated path delay values.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features, objects, and advantages of this invention will be apparent from reading this description in conjunction with the drawings, in which:
FIG. 1 is a block diagram of a known receiver for a digital communication system;
FIG. 2 is a block diagram of a receiver for a digital communication system in accordance with Applicants' invention; and
FIG. 3 is a flow chart of a method of weighting channel contributions.
DETAILED DESCRIPTION
This description is given in terms of a CDMA radio communication system for convenience only, and it will be appreciated that the principles of this invention can be applied in other digital communication systems having suitable characteristics. For example, those skilled in the art will appreciate that the teachings of the invention are equally applicable in any communication system in which it is desirable to optimize receiver performance in the presence of transmitted signal echoes.
FIG. 2 is a block diagram of a receiver 2 in a digital communication system that is in accordance with Applicants' invention. The carrier remover block 200 , propagation channel estimator block 202 , rake block 203 , and decoder and de-interleaver block 205 operate in substantially the same way as the corresponding blocks in FIG. 1 . FIG. 2 includes a propagation channel weights computer block 206 , which computes weights for each path delay that are used in the combiner block 204 as described in more detail below. Briefly stated, the data symbols of the selected paths are multiplied by the complex conjugates of the respective propagation channel estimates and by the respective computed weights, and the resulting symbols are added together over the number of delays as before, truncated, and fed to the de-interleaver and decoder.
Notation and System Modelling
Let u and v be complex numbers, u* be the complex conjugate of u, and |u| be the length of the vector u. Given a complex vector w, ∥w∥=|w 1 | 2 + . . . +|W n | 2 , where n is the number of elements in the vector w. Let x be a random variable and E(x) be the expectation value of x. Let 1 be a n×1 vector consisting of ones. Let I be the identity matrix. Assume that the received despread signal for delay f can be written as follows:
r f =h f s+n f
where h f is the impulse response of the propagation channel, s is the transmitted symbol, and n f is noise. For computing the weights in block 206 , the following expressions can be used:
y f =( ĥ f s (p1) )* r f (p1) =( ĥ f s (p1) )* ĥ f s (p1) +( ĥ f s (p1) )* n f
z f =( s (p2) )* r f (p2) =ĥ f +( s (p2) )* n f
where ĥ f is proportional to the propagation channel estimate. The propagation channel estimates may also be weighted by signal interference measurements or adjusted in other suitable ways to give ĥ f . In the preceding expressions, r f (p1) denotes the received pilot symbols (or training sequences) for the physical channel p 1 and s (p1) denotes the corresponding transmitted pilot symbols (or training sequences). The notation for the second physical channel p 2 corresponds to the notation for physical channel p 1 . In a WCDMA communication system, p 1 could be a dedicated physical channel (DPCH) and p 2 could be a common pilot channel (CPICH) for a downlink reception.
In the channel estimator block 202 , ĥ f is used as the channel estimates, and the y f and z f are computed in block 201 , which also determines and selects echoes for further processing as described in the U.S. patent applications that are cited above and that are incorporated here by reference. The y f can be considered a measure of how much signal energy is contained in the path delay f, and the z f can be considered an estimate of the propagation channel. The y f and z f are computed using the pilot symbols or other transmitted symbols that are known to the receiver in advance. In block 201 , the correlation matrix R is computed, the elements of which are given by:
R ij =E (( y i )* y j )
In a practical receiver, it is believed to be sufficient to estimate the matrix R by filtering the samples (y i )*y j .
Block 201 further computes a normalized correlation matrix C, the elements of which are given by:
C i j = E ( Re ( ( z i ) * z j ) ) E ( z i 2 ) E ( z j 2 )
and a mean energy vector M, the elements of which are given by:
M f =E ( y f )
It will be observed that each M f is a complex number.
The combiner 204 then combines the despread data, channel estimates, and channel weights according to the following expression:
∑ f = 1 F w f h ^ f * r f ( data )
where r f (data) are the received data symbols.
As described above, block 206 generates propagation channel weights that enable optimal soft symbol scaling in the combiner 204 . FIG. 3 is a flow chart of a method of weight generation that may be carried out in block 206 .
In step 301 , block 206 gets from the delay selector 201 the delays that should be used for despreading and combining the received data and statistical measures about the delays. In particular, block 206 obtains the matrices R and C and the vector M as the statistical measures, which should be adequate after a number of chips on the order of 100 have been processed.
In step 302 , the selected delays are identified as either peaks or neighbors. This identification can be carried out by first finding the delays with the largest |E(y f )|, or equivalently the largest |M f |, e.g., by ranking the delays selected by the selector block 201 , and identifying or tagging those as peaks. Then for each peak, the delays within a selected distance δ to the peak are found, and each such delay is identified or tagged as a neighbor of that peak. It is currently believed that δ is usually a distance of one-quarter, one-half, or three-quarters of a chip and that in general, neighbors need not be adjacent to each other. These steps are repeated for remaining non-identified delays until all delays have been identified.
In step 303 , the identified peaks and neighbors are grouped such that each group contains exactly one peak and its neighbors. It will be understood that a delay may belong to different groups as a neighbor.
In step 304 , weights are computed for the delays in each group without concern about delays that are duplicated in other groups. In the following three example computations, a group of delays indexed by f 1 , f 2 , and f 3 has y f1 , y f2 , and y f3 as the y f values associated with the delays, and the delay indexed by f 2 is identified as the peak. In these examples, it is assumed that each group includes three delays.
In the first example computation, block 206 computes weights for group members based on the signal energy contained in the group. The signal energy is given by:
Ω=(1− C f1f2 ) M f1 +(1 −C f2f3 ) M f3 +M f2
From this expression, Ω can be seen as the uncorrelated energy or SIR of the group. It will be noted that the signal energy from the same path is not allowed to be added twice. If all group delays are uncorrelated, it can be seen that:
Ω= M f1 +M f3 +M f2
which is not surprising since this arrangement reflects maximal diversity. At the opposite extreme when all group delays are correlated, we have:
Ω=M f2
which is also not surprising since this arrangement counts the energy from the peak only if the neighbors are completely correlated with the peak. The weight vector w=(w f1 , w f2 , w f3 ) is computed such that it minimizes the following mean square error expression:
E(|w f1 y f1 +w f2 y f2 +w f3 y f3 −|Ω∥ 2 )+β∥w−1∥ 2
The solution to the preceding expression is given by:
w =( R+βI ) −1 (|Ω| M *+β1)
It can be seen that if the parameter β is selected to be large, the weight vector w is proportional to the all-one vector 1 , and the larger that β is chosen to be, the more the weights are pushed to the value one, which has the effect of no weighting. Another purpose of β is to regularize the minimization problem, i.e., to guarantee that the inverse of the solution of the mean square error expression exists. Thus, choosing β>0 guarantees that R+βI has full rank, i.e., that its inverse exists. For a group comprising a peak and two neighbors, the inverse of a 3×3 matrix can be computed quickly and easily by hardware.
The value of β depends in part on how the channel estimates are generated by the estimator 202 , which advantageously implements channel estimation in the manner described in U.S. patent application Ser. No. 09/344,899 filed on Jun. 25, 1999, by E. Wang et al. for “RAKE Combining Methods and Apparatus Using Weighting Factors Derived from Knowledge of Spread Spectrum Signal Characteristics”. Channel estimation weighted by interference is also described in Proakis, Digital Communications, 3rd ed., McGraw-Hill. It is currently believed that it is advantageous to choose β as approximately ¼ of Ω.
In the second example computation, block 206 computes weights for group members in a simpler but less accurate approach by setting the weights as follows:
w f1 =1− C f1f2
w f2 =1
w f3 =1− C f2f3
which can be seen as penalizing neighboring delays that are highly correlated with the peak.
In the third example computation, block 206 computes weights for group members even more simply by setting the weights as follows:
w f1 =a (1−τ)
w f2 =a
w f3 =a (1−τ)
for selected constants a and τ. It is currently believed that a should be chosen between 0.8 and 1.5 and that it is particularly advantageous to choose a=1. It is also currently believed that τ should be chosen between 0.4 and 1 and that it is particularly advantageous to choose τ=0.75.
Returning to FIG. 3 , step 305 provides for checking for duplicate weights and determining one weight for each path delay. Some delays that have been identified as neighbors may be contained in two groups and therefore have two computed weight values. In this case, the weight with the minimum absolute value may be selected in order to minimize the impact of the contribution of neighboring delays in the combining of the sent data when it has been determined that a neighbor is correlated to a peak.
For a group comprising only two delays, the above-described computations are the same but with all terms involving f 3 removed.
For a group comprising five delays f 1 , . . . , f 5 indexed in time order with f 3 being the peak, the signal energy contained in the group can be taken to be given by:
Ω=(1− C f1f2 ) M f1 +(1− C f2f3 ) M f2 +M f3 +(1− C f3f4 ) M f4 +(1− C f4f5 ) M f5
for weight computation according to the first example computation described above, with an assumption that only adjacent delays could be correlated to any significant extent. For such a five-delay group and the second example computation described above, the weights are:
w f1 =1− C f1f2
w f2 =1− C f2f3
w f3 =1
w f4 =1− C f3f4
w f5 =1− C f4f5
For such a five-delay group and the third example computation, the weights are:
w f1 =a (1−τ 2 )
w f2 =a (1−τ 1 )
w f3 =a
w f4 =a (1−τ 1 )
w f5 =a (1−τ 2 )
for selected constants a, τ 1 , and τ 2 . As noted above, constant a should be chosen between 0.8 and 1.5, with a particularly advantageous value of a=1, and τ 1 and τ 2 should be chosen between 0.4 and 1, with a particularly advantageous value of 0.75.
In general, the parameters a, β, and τ (whether there is one or more τ) can be determined empirically or through numerical simulation by plotting bit error rate or a similar measure of sensitivity against received signal echo power with a, β, and τ as variable parameters.
It will be appreciated that the procedures described above are carried out repetitively as necessary to respond to the time-varying characteristics of the channel between the transmitter and receiver. These procedures are readily implemented by integrated circuits such as programmable processors and application-specific integrated circuits. Moreover, these example computations can be extended in a straightforward way for groups having more delays, with resulting increased computational effort of course. In addition, these computations can be generalized to include groups having non-adjacent correlated delays and to include computations for symbol-based interference cancellation, such as that described in U.S. patent application Ser. No. 09/344,899 cited above.
The steps of a computer program as illustrated in FIG. 3 for scaling path delay values in a communication system in which estimates of received symbols corresponding to the path delays are combined can be embodied in any computer-readable medium for use by or in connection with an instruction-execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch instructions from a medium and execute the instructions.
As used here, a “computer-readable medium” can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction-execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium include an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read only memory (ROM), an erasable programmable read only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read only memory (CDROM).
Those skilled in the art will appreciate that this invention is not limited to the embodiments described above for purposes of illustration and that numerous alternative embodiments are also contemplated. In addition, the terms “comprises” and “comprising”, as used in this description and the following claims, are meant as specifying the presence of stated features without precluding the presence of one or more other features. The scope of the invention is defined by the following claims rather than the foregoing description, and all equivalents consistent with the meaning of the claims are intended to be embraced therein. | Methods of scaling path delay values in a communication system, in which estimates of received symbols corresponding to the path delays are combined, include the step of determining a respective weight value for each path delay based on relative correlations of the path delays. The weight values may be determined by getting a plurality of path delay values; identifying the path delay values as either peak values or neighbor values; organizing the peak values and neighbor values into groups, with each group including at least one peak value and at least one neighbor value; for each group, determining a set of weight values; and checking the groups for duplicated path delay values and selecting a weight value from the weight values determined for the duplicated path delay values as either one of the weight values for the duplicated path delay values or a combination of the weight values for the duplicated path delay values. Receivers in digital communication systems and computer-readable media are also disclosed. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to garbage disposal and more particularly to an apparatus and method of rapidly, effectively of separating medium-sized materials (e.g., thin plastic plates, etc.) from garbage for collection.
[0003] 2. Description of Related Art
[0004] As to garbage disposal, typically there are techniques, i.e., landfill and burning, widely used throughout the world. Many precious lands are used for landfill as more garbage is generated everyday. Underground water and soil may be polluted by buried garbage if an appropriate disposal is not done. As to burning, it can cause severe air pollution if smoke generated during burning is not well processed prior to discharge. As to generated ashes, they are buried after being generated. Hence, the problem of polluting underground water and soil still exists. Further, it is often that residents violently protest a garbage disposal site to be established in their neighborhood because they think it may degrade their living quality once established. Furthermore, the cost of disposing garbage is increased significantly as less land being available for landfill.
[0005] Resources on earth begin to deplete in recent years. Hence, more and more people are aware of the importance of resource recycling by actively cooperating with the resource recycling policy. It is desired that amount of garbage can be reduced significantly in a near future by successfully recycling resources in order to prolong a useful time of land for burying garbage and preserve limited resources on earth.
[0006] However, the typical resource recycling (i.e., garbage recycling) techniques are unsatisfactory now. For example, a satisfactory garbage classification is not possible by the typical resource recycling techniques mainly because a wide. variety of different materials are contained in garbage. The materials comprise cotton products, cans made of aluminum or iron, plastic plates, plastic foam products, etc. More often that classification of such garbage is done by a disadvantageous manual process for being time consuming and tedious. Moreover, cleaning employees are susceptible of contracting diseases or being poisoned by contaminants or toxic materials contained in some cotton products or bottles mixed with garbage. Hence, a need for improvement exists.
[0007] Thus, it is desirable to provide a novel apparatus and method of separating medium-sized materials such as thin plastic plates or the like from garbage for collection in order to overcome the above drawbacks of the prior art.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an apparatus and method of effectively separating medium-sized materials from garbage for collection by means of wind and water.
[0009] It is another object of the present invention to provide an apparatus and method of separating medium-sized materials such as trash, bottles, floated articles, and submerged articles from garbage for collection.
[0010] It is yet another object of the present invention to provide a method of separating medium-sized materials from garbage for collection while performing an initial cleaning of garbage and a dilution of toxic materials in garbage by water for preventing the toxic materials from leaking, thereby significantly reducing a possibility of contracting diseases by or poisoning cleaning employees.
[0011] To attain the above mentioned objects and advantages, the method of the invention comprising the steps of:
[0012] (1) pouring garbage mixed with water into a conveyor screen assembly prior to separating a medium-sized garbage therefrom;
[0013] (2) separating heavy garbage and light garbage from the medium-sized garbage by blowing;
[0014] (3) separating empty cans and bottles from the light garbage by blowing; and
[0015] (4) separating floated and submerged articles from the remained garbage in the step (3) by water flow by discharging the light garbage from a inclined conveyor into a water channel and separating the floated and the submerged articles from the light garbage by water flow in the water channel for respectively collecting.
[0016] Preferably, the step (1) of the invention comprises the sub-steps of:
[0017] pouring the garbage mixed with water into the conveyor screen assembly to cause small garbage and organic matter to pass through the conveyor screen assembly for collection; and
[0018] blowing the not sifted medium-sized garbage out of a surface of the conveyor screen assembly for further processing by strong wind set up by a blower.
[0019] Preferably, the step (2) of the invention comprises the sub-steps of:
[0020] activating blowing means to blow air into a wind channel for forcing the medium-sized garbage to fall onto an inclined conveyor; and
[0021] continuing to transport the lighter garbage and the empty cans and bottles along the inclined conveyor and dropping the heavy garbage out of the inclined conveyor for collection.
[0022] Preferably, the step (3) of the invention comprises the sub-steps of:
[0023] blowing wind toward the cans, the bottles, and the lighter garbage on the inclined conveyor for continuing to carry the lighter garbage upward along the inclined conveyor; and
[0024] dropping the empty cans and bottles out of the inclined conveyor for collection wherein the empty cans and bottles substantially have a round shape or being multiangular and have a sufficient weight.
[0025] Preferably, the apparatus of invention comprising:
[0026] a conveyor screen assembly for permitting small, light garbage and organic matter in the garbage to pass through, the conveyor screen assembly comprising an internal blower proximate one end, the blower being adapted to obliquely blow air toward a surface and one end of the conveyor screen assembly;
[0027] a conveyor under one end of the conveyor screen assembly and perpendicular to a lengthwise direction of the conveyor screen assembly, the conveyor being adapted to transport the medium-sized garbage sent from the conveyor screen assembly to a next stage;
[0028] a waterway beneath both the conveyor screen assembly and the conveyor;
[0029] a baffle above the conveyor and in front of one end of the conveyor screen assembly, the baffle being adapted to deflect the medium-sized garbage blown from the conveyor screen assembly onto the conveyor;
[0030] a wind channel for receiving a discharge end of the conveyor, the wind channel including a first blowing means under the conveyor for blowing air into the wind channel;
[0031] a trash conveyor under and perpendicular to a lengthwise direction of the first blowing means, one end of the trash conveyor being horizontally extended away from the wind channel;
[0032] a trash collection container under a discharge end of the trash conveyor;
[0033] a gable wind shroud coupled to a discharge opening of the wind channel at its intake end, the wind shroud comprising a second blowing means at the intake end of the wind shroud, the second blowing means being adapted to blow air into the wind channel, the second blowing means being higher than the first blowing means, an internal inclined conveyor at a path of blowing air of the second blowing means, an angle of the inclined conveyor being adjustable and a top of the inclined conveyor being spaced apart from a bottom of a vertex of the wind shroud for permitting a free garbage pass therebetween, a bottle conveyor below the inclined conveyor, and a bottle collection tray below a discharge end of the bottle conveyor; and
[0034] a water channel below a discharge opening of the wind shroud opposite the wind channel, the water channel comprising a drain pipe extended from a bottom thereof, an inclined submerged article conveyor above the drain pipe, a submerged article collection container below a discharge end of the submerged article conveyor, a top recess at a side wall of the water channel, an inclined sprinkler including a plurality of injection nozzles for obliquely spraying water toward a surface of the water channel and the recess, and a collection vessel below and adjacent the recess for storing water and floated articles.
[0035] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] [0036]FIG. 1 is a flow chart showing a sequence of method steps performed by an apparatus according to the invention;
[0037] [0037]FIG. 2 is a perspective view of a preferred embodiment of the apparatus;
[0038] [0038]FIG. 3 is an enlarged view of a portion of FIG. 3;
[0039] [0039]FIG. 4 is a side view of FIG. 3 schematically illustrating a portion of garbage disposal flow performed by the apparatus; and
[0040] [0040]FIG. 5 is a side view schematically illustrating the garbage disposal flow performed by the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Medium-sized garbage of the invention is defined as thin plastic plates, floated articles (e.g., bottles, food containers made of plastic foam, and leaves), or submerged articles (e.g., shoes, boards, detachable products, and diapers). For ease of discussion, they are collectively called medium-sized garbage.
[0042] First mix garbage with water. Next, remove heavy or large garbage (i.e., garbage sunk in water) from garbage. A sequence of method steps are then performed by an apparatus of separating medium-sized materials from garbage for collection in accordance with the invention as referring to FIG. 1.
[0043] In step 1 , pour garbage mixed with water into a conveyor screen assembly prior to separating medium-sized garbage therefrom. In detail, pour garbage mixed with water into a conveyor screen assembly to cause small garbage and organic matter to pass through meshed openings of the conveyor screen assembly for collection. The not sifted medium-sized garbage will be blown out of the conveyor screen assembly for further processing by strong wind set up by a blower.
[0044] In step 2 , separate heavy garbage and light garbage from the medium-sized garbage by blowing. In detail, activate a blowing device to blow air into a wind channel for forcing the medium-sized garbage to fall onto an inclined conveyor in which light garbage, cans, or bottles will continue to carry along the inclined conveyor and heavy garbage will be dropped out of the inclined conveyor for collection.
[0045] In step 3 , separate empty cans and bottles from the light garbage by blowing. In detail, blow a strong wind toward cans, bottles, and light garbage on the inclined conveyor in which the light garbage will continue to be carried upward along the inclined conveyor by the strong wind blown thereonto and empty cans and bottles substantially having a round shape or being multiangular and having a sufficient weight, they will drop out of the inclined conveyor for collection.
[0046] In step 4 , separate floated and submerged articles from the remained garbage by water flow. In detail, light garbage discharged from the inclined conveyor will drop into a water channel. Next, separate floated and submerged articles from the light garbage by water flow in the water channel for respectively collecting.
[0047] Referring to FIGS. 2, 3, 4 , and 5 , the apparatus of separating medium-sized materials from garbage for collection is shown. The apparatus comprises a conveyor screen assembly 10 for permitting small, light garbage and organic matter in garbage to pass through. The conveyor screen assembly 10 comprises an internal blower 11 proximate one end of the conveyor screen assembly 10 , the blower 11 being adapted to obliquely blow air toward a surface and one end of the conveyor screen assembly 10 , and an internal sprinkler assembly 12 for upwardly spraying water toward the conveyor screen assembly 10 . The apparatus further comprises a first conveyor 20 under one end of the conveyor screen assembly 10 and perpendicular to a lengthwise direction of the conveyor screen assembly 10 , the first conveyor 20 being adapted to transport medium-sized garbage sent from the conveyor screen assembly 10 to a next stage as detailed later, a waterway 40 beneath both the conveyor screen assembly 10 and the first conveyor 20 , a baffle 30 above the first conveyor 20 and in front of one end of the conveyor screen assembly 10 , the baffle 30 being adapted to deflect the medium-sized garbage blown from the conveyor screen assembly 10 onto the first conveyor 20 , and a shaft 13 including a plurality of equally spaced apart, arcuate, and axial revolving vanes 130 on its outer surface. The shaft 13 can rotate clockwise (see FIG. 4). A gap S of about 3 cm to about 10 cm is formed between one end of the conveyor screen assembly 10 and the outermost point of the vane 130 . Also, the gap S is adjustable.
[0048] The apparatus further comprises a wind channel 50 for receiving the other end of the first conveyor 20 , the wind channel 50 including a first blowing device 51 under the first conveyor 20 for blowing air into the wind channel 50 , a trash conveyor 60 under and perpendicular to a lengthwise direction of the first blowing device 51 , one end of the trash conveyor 60 being horizontally extended away from the side of the wind channel 50 , a trash collection container 61 under one end of the trash conveyor 60 , a gable wind duct 70 having one end coupled to a discharge opening of the wind channel 50 , the wind duct 70 comprising a second blowing device 71 at the junction of the wind duct 70 and the wind channel 50 , the second blowing device 71 being adapted to blow air into the wind channel 50 , the second blowing device 71 being higher than the first blowing device 51 , a reverse conveyor 72 under the second blowing device 71 but above the trash conveyor 60 , the reverse conveyor 72 including a plurality of rows of needles 720 made of nylon on an endless transfer belt thereof, an internal inclined second conveyor 73 adjacent the reverse conveyor 72 , an inclined angle of the second conveyor 73 being adjustable, the top of the second conveyor 73 being spaced apart from the bottom of a vertex of the wind duct 70 for permitting garbage to pass therebetween, a bottle conveyor 74 below and between the second conveyor 73 and the reverse conveyor 72 , and a bottle collection tray 75 below a discharge end of the bottle conveyor 74 .
[0049] The apparatus further comprises a water channel 80 below a discharge opening 700 of the wind duct 70 opposite the wind channel 50 , the water channel 80 comprising a drain pipe 82 extended from its bottom, an inclined submerged article conveyor 83 above the drain pipe 82 , a submerged article collection container 84 below a discharge end of the submerged article conveyor 83 , a top recess 800 at a side wall of the water channel 80 , an inclined sprinkler 90 having a plurality of injection nozzles 91 for obliquely spraying water toward a surface of the water channel 80 and the recess 800 , and a collection vessel 81 below and adjacent the recess 800 for storing water and floated articles including products made of plastic foam.
[0050] An operation of the invention will now be described below by referring to FIGS. 2 to 5 again. First mix garbage with water. Next, remove heavy or large garbage (i.e., garbage sunk in water) from garbage. Next, pour garbage mixed with water into the conveyor screen assembly 10 . Small garbage will pass through meshed openings of the conveyor screen assembly 10 to fall onto the waterway 40 under the conveyor screen assembly 10 . Water in the waterway 40 will transport the small garbage to a next stage for processing which is not pertinent to the invention. Thus a detailed description thereof is omitted herein for the sake of brevity. The garbage not sifted is continuously transported toward the first conveyor 20 and medium-sized, light materials in garbage are immediately blown out of the surface of the conveyor screen assembly 10 by strong wind set up by the blower 11 . The blown medium-sized garbage is blocked and deflected by the baffle 30 to fall onto the first conveyor 20 . The medium-sized garbage (e.g., containers full of water or bottles full of water) having a size larger than the gap S between one end of the conveyor screen assembly 10 and the outermost point of the vane 130 will contact the vanes 130 . The revolving vanes 130 then convey them to fall onto the first conveyor 20 . As to garbage having a size less than the gap S will drop into the waterway 40 to be carried away for further processing.
[0051] For the medium-sized garbage fallen on the first conveyor 20 , it will be transported into the wind channel 50 to fall onto the trash conveyor 60 . At this time, the first blowing device 51 is activated to blow air into the wind channel 50 . As such, in the wind channel 50 medium-sized, light materials in garbage (e.g., articles made of plastic foam, empty bottles, etc.) carried from the first conveyor 20 will be blown to fall onto the second conveyor 73 by passing over the trash conveyor 60 and the reverse conveyor 72 . The activated second conveyor 73 will carry the medium-sized garbage upwardly. For medium-sized garbage having a sufficient weight, it will fall onto the trash conveyor 60 because the blowing strength set up by the first blowing device 51 has a limit. Garbage fallen on the trash conveyor 60 will be carried to the trash collection container 61 for further processing. Note that some materials in the medium-sized garbage (e.g., ropes soaked with water, diapers, or half full bottles and cans, etc.) may have a weight sufficient to be blown up by the first blowing device 51 but they cannot pass over the reverse conveyor 72 . The invention takes them as trash in processing. Hence, a transporting direction of the reverse conveyor 72 is toward the trash conveyor 60 . In other words, those materials in the medium-sized garbage will be carried by the reverse conveyor 72 to fall onto the trash conveyor 60 for processing. The provision of the rows of needles 720 on the trash conveyor 60 aims at catching the above ropes, diapers, etc. For preventing them from being blown out of the reverse conveyor 72 again by the current of air blown by the first blowing device 51 if they have dried during transporting.
[0052] As to light garbage fallen onto the second conveyor 73 as blown by the first blowing device 51 , it may be either empty bottles, cans, etc. or articles made of plastic foam, plastic plates, papers, etc. For example, empty bottles or cans substantially have a round shape or being multiangular and have a sufficient weight. Further, they are distal from the first blowing device 51 . As a result, they will slide down along the second conveyor 73 to fall onto the bottle conveyor 74 as they are conveying upward along the second conveyor 73 . The empty bottles or cans fallen on the bottle conveyor 74 will be carried to drop into the bottle conveyor 74 for further processing. As to articles made of plastic foam, plastic plates, papers, etc., they will be continuously carried by the second conveyor 73 until a predetermined height has been reached. That is, at the predetermined height the current of air blown by the first blowing device 51 does not have a sufficient strength to maintain they to stay on the bottle conveyor 74 . Also, about at the predetermined height the second blowing device 71 will blow air toward these articles made of plastic foam, plastic plates, papers, etc. To cause them to still stay on the bottle conveyor 74 for carrying. Moreover, strong air set up by the second blowing device 71 will blow articles made of plastic foam, plastic plates, papers, etc. To fall into the water channel 80 from the discharge opening 700 of the wind duct 70 after passing the wind duct 70 . As to articles made of plastic foam, plastic plates, papers, etc. fallen into the water channel 80 , they will be carried toward the sprinkler 90 and the submerged article conveyor 83 by water flow. At this time, articles made of plastic foam, etc. will float on the water channel 80 . As such, the strong water sprayed by the injection nozzles 91 of the sprinkler 90 will push the floated articles made of plastic foam, etc. To drop into the collection vessel 81 for further processing after leaving the recess 800 . As to those plastic plates, papers, etc. (i.e., submerged article), they will continue to carry toward the submerged article conveyor 83 by water flow. The submerged article conveyor 83 will carry the arrived plastic plates, papers, etc. to its end prior to dropping them into the submerged article collection container 84 for further processing.
[0053] The benefits of the invention include (1) providing a novel and unique garbage disposal implementation of rapidly, effectively, conveniently, and precisely separating medium-sized garbage from garbage for collection by means of wind and water; (2) performing an initial cleaning of garbage by means of water while classifying garbage for facilitating a subsequent garbage recycling; (3) diluting toxic materials in garbage by means of water while classifying garbage for reducing a possibility of contracting diseases by people; and (4) providing an apparatus capable of effectively, rapidly, and precisely separating medium-sized garbage from garbage for collection.
[0054] While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. | An apparatus and method of separating medium-sized materials such as trash, bottles, floated articles, and submerged articles from garbage for collection by means of wind and water is disclosed. Moreover, an initial cleaning of garbage and a dilution of toxic materials contained therein are performed while disposing garbage, thereby significantly reducing a possibility of contracting diseases by or poisoning cleaning employees. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates generally to improvements in key-exchangeable locks and, it relates more particularly to an improved lock mechanism permitting the reliable performance of a key-exchanging procedure without any improper operation during the course of such procedure.
With the key-exchangeable lock of the prior art, an error in the sequence of the key-exchanging procedure not only makes it impossible to exchange the existing key to a desired new key but also results in the disabling of the releasing mechanism and it has usually been necessary to then disassemble the lock and to reassemble the tumblers. Such a lock has been disclosed, for example, by U.S. Pat. No. 4,072,032. In this prior art lock, the centre around which the tumblers are rotated is displaceable and, as a consequence, the running plate is also movable even when the predetermined key does not assume the lock releasing position in which the tumblers are held at their released positions. As a result, an erroneous operation would bring the fence out of the gates of the tumblers so that the tumblers are disassembled. If the operator is not familiar with the proper sequence of the key-exchanging procedure, there is a danger that such an erroneous operation might often occur.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide an improved key-exchangeable lock mechanism so constructed that any erroneous operation is eliminated and the key-exchange procedure can be reliably and easily achieved, the improved mechanism being simple and rugged and overcoming the disadvantages of the earlier structures.
This object is achieved, according to the present invention, by an arrangement in a lock in which the centre around which the tumblers are rotated is displaced and whereby the desired key-exchange is effected wherein the rotational centre of the tumblers can neither be displaced nor fixed unless the tumblers are held by a predetermined key at their lock releasing positions.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front elevational view of a key-exchangeable lock mechanism in accordance with the present invention as applied to a leased safe-deposit box provided with a client lock and a bank lock;
FIG. 2 is a view similar to FIG. 1 but with the tumblers not illustrated;
FIGS. 3 through 6 are schematic front views similar to FIG. 1 showing the essential successive steps in the key-exchanging operation for the client lock;
FIGS. 7 through 10 are fragmentary schematic front views showing the important parts at the respective successive essential steps of the key-exchanging operation for the bank lock; and
FIG. 11 is a rear perspective view showing the running plate and conversion shaft of the key-exchange mechanism.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention will be now described more in detail with reference to a preferred emobdiment as shown by the accompanying drawings.
Referring to the drawings which illustrate a preferred embodiment of the present invention, the reference numeral 11 generally designates a lock housing in which all of the lock members are arranged and which is mounted on the door of a safe-deposit box. A locking bar 21 is formed and integrally movable with a running plate 22 so that the bar 21 may be advanced and projected out from and retracted into the lock housing 11. The running plate 22 is provided with fences 23, 24 and these fences 23, 24 cooperate with tumblers as will be hereinafter described, so as to prevent and to permit the retraction of said running plate 22. An opening 25 (FIG. 2) is formed in the running plate 22 to receive therein a conversion shaft and a tumbler supporting shaft as weill be described later. Reference numeral 31 designates tumblers for a client lock. Although only one of the tumblers 31 is shown for clarity of illustration, it should be understood that a plurality of tumblers are normally successively stacked preferably with spacers interposed between the respective pairs of adjacent tumblers. Each of the tumblers 31 is provided in its side opposed to the fence 23 with a gate 32 into which fence 23 can enter and provided along an end opposite to said gate 32 with engaging notches 34 in the form of saw-teeth. The engaging notches 34 can engage and disengage an associated one of two diametrically opposed projections formed on a supporting shaft 71 which is, in turn, stationarily mounted in the lock housing 11. When one of these engaging notches 34 engages the associated projection on supporting shaft 71, the tumblers 31 may be rotated or rocked around said one of the engaging notches 34. There is provided adjacent a middle and upper portion of the tumblers 31 a spring normally biasing tumblers 31 downward so that the tumblers 31 are biased to rotate counterclockwise so far as the engaging notches 34 are engaged with the supporting shaft 71. There is provided between the gate 32 and the engaging notches 34 a fan-shaped or curved opening 33 through which a conversion shaft 35 extends. The conversion shaft 35 is rotatably supported in the lock housing 11 and so formed as to be rotatable by a prescribed conversion key from the rear side of the lock housing 11. Further, the conversion shaft 35 includes an eccentric portion 36 adapted to bear against the right side concave surface of the opening 33 formed in the tumblers 31 when the conversion shaft 35 assumes its fixed position as shown by FIGS. 1 and 2, urging the tumblers 31 toward the supporting shaft 71 so that one of the engaging notches 34 may be engaged with the associated projection formed on the supporting shaft 71. There is provided between the opening 33, the conversion shaft 35 and the eccentric portion 36 a play sufficient to allow the tumblers 31 to be smoothly rotated around the engaging notches 34 but so limited as to prevent the engaging notches 34 from being disengaged from the associated projection on the supporting shaft 71. Reference numerals 37 and 38, respectively, designate a stop piece and a locking piece formed integrally with the conversion shaft 35 and located within an opening 25 adjacent the front side and adjacent the rear side, respectively, (FIG. 11). Reference numeral 41 designates a predetermined client key and reference numberal 42 designates a key guiding member rotatably supported in the lock housing 11 and adapted to receive and rotatably support the client key 41. Integrally formed with key guiding member 42 is an arm 43 to permit the running plate 22 to longitudinally slidably retract and advance along a given end surface of the opening 25 formed in running plate 22.
The reference numeral 51 designates tumblers of the bank lock and although only one tumbler is shown for simplified illustration, there are normally provided a stacked plurality of such tumblers as in the case of the tumblers 31 for the client lock. Each of the tumblers 51 is provided along its left side edge with spaced engaging notches 54 in the form of saw-teeth and in its right side portion with an opening to receive the fence 24 and a gate 52 formed in continuity with said opening. The gate 52 allows the fence 24 to enter thereinto and allows the running plate 22 to be retracted. There is provided between the engaging notches 54 and the gate 52 a fan-shaped or arcuate opening 53. Selected engaging notch 54 releasably engages the other projection formed on the supporting shaft 71 and, when such engagement is established, the tumblers 51 are rotatable around the respective engaging notches 54. Adjacent the middle upper portion of the tumblers 51, there is provided a spring normally downwardly biasing the tumblers 51, so that the tumblers 51 are rockably biased clockwise when engaging notches 54 are engaged with said other projection on the supporting shaft 71. A conversion shaft 55 extends through the opening 25 of the running plate 22 and an opening 53 formed in the tumblers 51. Conversion shaft 55 is rotatably supported in the lock housing 11 and is rotatable by a predetermined conversion key from the rear side of the lock housing 11. Furthermore, the conversion shaft 55 is provided with an eccentric portion 56 which, at the normal position as shown by FIG. 1, bears against the left side surface of the opening 53, urging the tumblers 51 against the supporting shaft 71 so that one of the engaging notches 54 is engaged with the other projection on the supporting shaft 71. Between the opening 53, the conversion shaft 55 and the eccentric portion 56, there is provided a play sufficient to allow a smooth rotation of the tumblers 51 around the engaging notches 54 but limited so as to prevent the engaging notches 54 from being disengaged from said other projection. A stop piece 57 is formed integrally with the conversion shaft 55 and located within the opening 25 of the running plate 22 adjacent the front side thereof. A locking piece 58 is formed on stop piece 57 and located within the opening 25 adjacent the rear side thereof (FIG. 11).
Reference numeral 61 designates a predetermined bank key and reference numeral 62 designates a key guiding member rotatably supported in the lock housing 11 and adapted to rotatably support bank key 61. Integrally with the key guiding member 62, there is formed a locking piece 63 located within a transverse extension of the running plate 22 in the direction of its thickness.
Considering now the manner in which the safe-deposit box lock mechanism described above is manipulated and operated FIGS. 1 and 2 both correspond to the mechanism locked state. In this state, the fences 23, 24 are in engagement with the ends of the gates 32, 52, respectively, to block retraction of running plate 22 which is in its locked position so that the locking bar 21 cannot be retracted into the lock housing. The stop piece 37 has its upper end in engagement with the upper face of opening 25 so as to prevent the conversion shaft 35 from being further rotated while the stop piece 57 has its right end in engagement with the right face of opening 25 so as to prevent the conversion shaft 55 from being further rotated, so that both conversion shafts 35, 55 are held in their fixed positions.
To unlock, the predetermined bank key 61 is inserted into the key guiding member 62 and then rotated clockwise until the key 61 is vertically oriented as viewed in the drawings. During such manipulation, the key crest of the bank key 61 bears against the lower ends of the tumblers 51, urging them upward and the tumblers 51 are rotated counterclockwise around the engaged notches 54. Thus the tumblers 51 are held at their unlocked positions at which the gate 52 is longitudinally aligned with the fence 24.
Then, the prescribed client key 41 is inserted into the key guiding member 42 and rotated clockwise. The key crest of the client key 41 bears against the lower ends of the tumblers 31 and client key 41 is rotated to a substantially vertical orientation as viewed in the drawings so that the tumblers 31 are urged upward and rotated clockwise around the respective engaged notches 34. Thus the tumblers 31 are held at their unlocked positions at which the gate 32 is longitudinally aligned with the fence 23. During further clockwise rotation of the client key 41, the arm 43 comes in slidable contact with a given end surface of the opening 25 formed in the running plate 22, retracting the fence 23 into the gate 32 and the fence 24 into the gate 52 so that the running plate 22 is retracted thereby to its unlocked position. Concurrently, the locking bar 21 is retracted into the lock housing and unlocking is completed. After the bank key 61 is brought back to its lock position and withdrawn from the key guiding member, merely bringing the client key 41 back to its lock position causes the running plate 22 to be advanced to its lock position and causes, at the same time, the locking bar 21 to project from the lock housing. Concurrently, the fences 23, 24 leave the respective gates 32, 52 and the tumblers 31, 51 are rotated counterclockwise and clockwise, respectively, under the influence of the associated springs and automatically return to their lock positions as shown in FIG. 1. The manipulation and the operation which have been described hereinabove are identical to those of the prior safe-deposit box lock mechanism.
Now a manner in which the key-exchange is accomplished will be described in detail. In the case of the embodiment as described above and as shown, the improved mechanism is adapted for mutually independent key-exchanges for the client lock and the bank lock. Accordingly an explanation will first be given for the key-exchange of the client lock which occurs more frequently than the key-exchange of the bank lock.
As will be best seen in FIG. 2, the conversion shaft 35 is not rotatable when the running plate 22 occupies its lock position, since the stop piece 37 is substantially in engagement with both the upper and the lower opposing end faces of the opening 25. The client lock and the bank lock are released by the prescribed client and bank keys 41, 61, respectively, and the locking bar 21 is thus retracted into the lock housing. Consequently fence 23 enters gate 32 and running plate 22 has its engaging portion 26a (FIG. 11) formed on the left end surface of the opening 25 thereof as a part of the running plate 22, which is defined by a rear side half of its thickness, bearing against the outer periphery of locking piece 38 carried by the conversion shaft 35. Thus the running plate 22 is held at its unlock position (FIG. 3). So long as the running plate 22 is held at this unlock position, a widened zone of the opening 25 is approximately above conversion shaft 35 and, in consequence, stop piece 37 for the conversion shaft 35 is disengaged from the opening 25. The locking piece 38 is in the form of a sector projecting from the conversion shaft 35 and concentric with the axis of the conversion shaft 35. The outer peripheral surface of this sector is in contact with the engaging portion 26a which is correspondingly curved relative to said outer peripheral surface so that the locking piece 38 does not prevent the conversion shaft 35 from being rotated. Therefore, the conversion shaft 35 can be rotated counterclockwise by the conversion key from its fixed position as shown by FIG. 3.
FIG. 4 shows the position for conversion at which the conversion shaft 35 has been rotated counterclockwise from its fixed position substantially by 90°. The conversion shaft 35 is prevented by a stop planted on the lock housing 11 from further counterclockwise rotation. During this rotation of the conversion shaft 35 substantially by 90°, the eccentric portion 36 which has been pressed against the right-hand surface of the opening 33 formed in the tumblers 31 now slidably bears against the left-hand surface of the opening 33 and thereby moves the tumblers 31 leftward. This movement causes the engaging notches 34 to disengage the associated projection on the supporting shaft 71 and the tumblers 31 become rotatable around a point at which the gate 32 bears against the fence 23 so that the tumblers 31 are rotated under the biasing effect of the associated spring until the lower end surfaces of the tumblers 31 come into contact with the key crest of the client key 41. After the conversion shaft 35 has been rotated to the position for conversion as shown by FIG. 4, the locking piece 38 parts from the engaging portion 26a and it becomes possible to further retract the running plate 22.
FIG. 5 corresponds to the state in which the client key 41 has been further rotated clockwise and thereby the running plate 22 has been further retracted to the position for conversion. During said further clockwise rotation of the client key 41, the tumblers 31 with their lower end surfaces bearing against the key crest of the client key 41 are rotated around the point at which they bear against the fence 23. So far as the running plate 22 occupies the position for conversion, a lower step of the engaging portion 26a is engaged with a terminal step of the sector serving as the locking piece 38 and thereby prevents the conversion shaft 35 from being rotated clockwise. The conversion shaft 35 is thus held at the position for conversion. The key guiding member 42 is so shaped that it allows the key-exchange at the position for conversion as shown by FIG. 5 and at this position the client key 41 may be replaced by a new client key 41'.
After the new client key 41' has been inserted into the key guiding member 42, this client key 41' is rotated counterclockwise. During this rotation, the tumblers 31 are lifted by the key crest of the client key 41' slidably bearing against the lower end surfaces of tumblers 31 and rotated around the point at which the gate 32 bears against the fence 23. The running plate 22 is advanced as the end surface of its opening 25 is urged by the arm 43. After the client key 41' has been rotated in the manner of normal unlocking manipulation to the unlock position at which the gate 32 of the tumblers 31 is aligned with the fehce 23, the engaging portion 26b (FIG. 11) formed in the opening 25 at its rear side is engaged with the locking piece 38 to block advancement of the running plate 22 and, as a result, the client key 41' cannot be further rotated counterclockwise. In this state, the step of the locking piece 38 is no longer engaged with the corresponding step of the engaging portion 26a and the conversion shaft 35 is therefore allowed to be rotated clockwise (FIG. 6). When the conversion shaft 35 is rotated clockwise by the key for conversion to its fixed position, the eccentric portion 36 is pressed against the right side surface of the opening 33 formed in the tumblers 31 and displaces the tumblers 31 with their lower end surfaces maintained in contact with the key crest of the client key 41' in such a direction that one of the engaging notches 34 comes into engagement with the associated projection on the supporting shaft 71. Upon engagement of said one notch with said projection, it becomes possible to advance the running plate 22 to the lock position and thus conversion of the axis around which the tumblers 31 are rotatable, namely, manipulation of key-exchange, is completed. With such manipulation as has been described hereinabove, the safe-deposit box can be locked and unlocked by use of the new client key 41'.
In the key-exchange procedure for the bank lock, in the locking position as shown by FIG. 2, the engaging portion 57b of the stop piece 57 bears against the lower end surface of the opening 25 to prevent the conversion shaft 55 from being rotated counterclockwise while the engaging portion 57a of the stop piece 57 bears against the right-hand surface of the opening 25 formed in the running plate 22 to prevent the conversion shaft 55 from being rotated clockwise. Thus, the conversion shaft 55 is held at its fixed position.
Also for the key-exchange of the bank lock, the safe-deposit box is unlocked by the prescribed bank and client keys 61, 41, first of all (FIG. 3). When the running plate 22 is retracted to the unlock position, the fence 24 enters into the gate 52 and the right end surface of the opening 25 parts from the engaging portion 57a so that the conversion shaft 55 can be rotated clockwise. Now the conversion shaft 55 is rotated clockwise by the conversion key substantially by 90° to the position for conversion. During this rotation, the eccentric portion 56 is slidably pressed against the right side surface of the opening 53 formed in the tumblers 51 and thereby moves the tumblers 51 rightward while the tumblers 51 are maintained along their lower end surfaces in contact with the key crest of the bank key 61. As the tumblers 51 are thus moved rightward, the engaging notches 54 are disengaged from the associated projection on the supporting shaft 71 and the tumblers 51 become rotatable around the point at which the gate 52 bears against the fence 24. Such a state is shown by FIG. 7. In this state, the engaging portion 57b of the locking piece 57 bears against the step of a recess 27a formed in the upper edge of the opening 25 on the front side so that, when the running plate 22 is advanced by rotating the client key 41 in the direction of locking, the conversion shaft 55 is rotated counterclockwise by the stop piece 57 back to the fixed position and thus the tumblers 51 are brought back to the positions as shown by FIG. 1.
When the bank key 61 is rotated from the position as shown by FIG. 7 to the lock position, the tumblers 51 are rotated counterclockwise under the influence of the associated spring around the point at which the gate 52 bears against the fence 24. In this state, the locking piece 63 formed integrally with the key guiding member 62 is in engagement with the locking piece 58 for the conversion shaft 55 and thereby the conversion shaft 55 is restrained against clockwise rotation, namely, it is impossible to bring the conversion shaft 55 back to the fixed position (FIG. 8). Accordingly, the client key 41 cannot be rotated to the lock position, in this state, since the running plate 22 is prevented from being retracted.
From the state of FIG. 8, the bank key 61 is pulled out from the key guiding member and a new bank key 61' is inserted therein and is rotated clockwise or in the direction of normal unlocking. During this rotation, the tumblers 51 are lifted by the key crest of the bank key 61', being slidably pressed against the lower end surfaces of the tumblers 51 and rotated clockwise around the point at which the gate 52 bears against the fence 24. In this state, the locking piece 63 is out of engagement with the locking piece 58 and accordingly the conversion shaft 55 can be rotated counterclockwise to the fixed position (FIG. 9). During this counterclockwise rotation of the conversion shaft 55 to the fixed position, the eccentric portion 56 is slidably pressed against the left end surface of the opening 53 formed in the tumblers 51, moving the engaging notches 54 toward the supporting shaft 71 while the tumblers 51 are maintained in contact with the key crest of the bank key 61' along the lower end surfaces of the tumblers 51 until one of said engaging notches 54 comes into engagement with the associated projection of the supporting shaft 71. The key-exchange procedure is thus completed and the safe-deposit box can be locked and unlocked by the new bank key 61'.
As clearly understood from the foregoing description, the lock constructed according to the present invention is free from a danger of falling into a non-releasable state even when the prescribed keys for unlocking or conversion are rotated in an erroneous sequence, so far as these keys are rotated in the rotatable directions.
The particular embodiment as shown is so arranged that, when the running plate 22 occupies its position for conversion, the locking piece 63 of the key guiding member 62 bears against the engaging portion 27b formed on the rear side of the running plate 22 so as to block the rotation of the bank key (FIG. 5) so that the client key and the bank key cannot be simultaneously rotated in the direction of unlocking. However, an alternative arrangement is also possible by removal of said engaging portion 27b so that both the client key and the bank key can be simultaneously key-exchanged.
The key-exchangeable lock of the present invention constructed as described above possesses numberous advantages. Even when an improper procedure of manipulation is effected, or vibration or other undesirable conditions occur during the normal locking and unlocking procedures, there is no danger of the inadvertent shifting of the rotational axis of the tumblers in the locked state, since the conversion shaft is prevented from being rotated and, in the unlocked state, the conversion shaft is rotated from its fixed position but there is no danger that a locking might occur with the rotational axis of the tumblers being displaced, since the locking cannot be achieved unless the conversion shaft occupies its fixed position.
During the key-exchange operation, the keys or the conversion shaft can be rotated only in the direction for proper key-exchange or in the direction tracing back this sequence of proper key-exchange. Accordingly, there is no danger that the tumblers might be fixed with their rotational axis being displaced even when the operator forgets the proper sequence of key-exchange or follows an erroneous sequence. It is possible with the mechanism of the present invention to arrange the tumblers so that the locking and the unlocking may be achieved by the initial keys or the new keys.
The key-exchangeable lock according to the present invention can be conveniently used for various applications such as for a safe-deposit box as shown in the accompanying drawings as the preferred embodiment. | A lock includes a running plate formed integrally with a locking bar and provided with a fence adapted to cooperate with a plurality of tumblers so as to alternatively block and allow retraction of the locking bar, and this mechanism is mounted together with the cooperating components within a lock housing. The tumblers allow retraction of the locking bar when moved by a prescribed key to a unlocking position and this prescribed key, which can move the tumblers to the unlocking position, can be exchanged with another prescribed key by displacing the rotational axes of the tumblers. The rotational axes of the tumblers are rotatably released or fixed by a conversion shaft extending through an opening formed in the tumblers and rotatably supported in the lock housing. The conversion shaft is provided with a stop piece and a locking piece. An operative association is established among the conversion shaft, the running plate and a key guiding member rotatably supporting the prescribed key so that it is impossible to release the rotational axes for its displacement or to fix the rotational axes thus released unless the tumblers have been moved to the unlocking position and are held at this unlocking position. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to Japanese Patent Application Nos. 2006-196190 and 2006-196191, filed Jul. 18, 2006 and Jul. 18, 2006, respectively, of which full contents are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a data processing circuit and a data processing method.
[0004] 2. Description of the Related Art
[0005] FIG. 10 illustrates the configuration of a data input processing system 1 that is applied to car audio systems or the like. The data input processing system 1 includes a main device 10 and a display device 20 that is detachable from the main device 10 .
[0006] The main device 10 is equipped with mechanisms and circuits to achieve the functions of a car audio system such as a CD or DVD player, a radio receiver, etc. On the other hand, the display device 20 is provided with a display panel 21 to indicate information on the control or the operation of the car audio system, a data input processing circuit 22 , a key scanning circuit 23 , a rotary encoder 24 , and a remote control receiver 25 .
[0007] The main device 10 is equipped with a controller 11 to control indication on the display panel 21 , and to receive signals from the key scanning circuit 23 , the rotary encoder 24 , and the remote control receiver 25 . The controller 11 inputs a clock signal CL, a data input signal DI, and a chip enable signal CE to an input interface 221 in the display device 20 for the display control or for the reception of the signals.
[0008] The input processing circuit 22 in the display device 20 includes the input interface 221 that communicates with the controller 11 , a control register 222 that memorizes input data that is input from the controller 11 , a display control unit 223 that controls the display panel 21 based on display data that is input as the input data, a signal generating unit 224 that provides a driving signal such as an operational clock signal for the display control unit 223 , and a signal selecting circuit 225 that selects either a key scanning signal or a rotary encoder detecting signal (hereinafter, these are collectively referred to as a slow processing signal), corresponding to the address data that is input from the controller 11 as a data-output request to be memorized at the control register 222 , and that outputs the selected slow processing signal.
[0009] The display device 20 is also equipped with a circuit (e.g., remote control receiver 25 ) that generates a signal with a short sampling period (hereinafter, referred to as a fast processing signal). The fast processing signal cannot be synchronized with a clock signal that is input from the main device 10 due to the insufficient processing capacity of a processor mounted on the display device 20 , and therefore, it is output to the main device 10 via an independent signal line different from a signal line for the slow processing signals. (refer to Japanese Patent Application Laid-Open Publication No. 8-221174)
[0010] In the case, as above, that individual signal lines to output a fast processing signal and a slow processing signal are arranged independently, the number of lines to connect the main device 10 and the display device 20 increased, and thus wiring becomes complicated. Thereby, the possibility of such a trouble as a faulty connection increases, and the manufacturing cost also increases due to the increased number of parts.
SUMMARY OF THE INVENTION
[0011] A data processing circuit according to an aspect of the present invention, comprises: a first circuit configured to time-division-multiplex a first digital signal synchronous with a clock signal input from an external controller and a second digital signal asynchronous with the clock signal; and a second circuit configured to output a digital signal time-division-multiplexed by the first circuit to the controller.
[0012] Other features of the present invention will become apparent from descriptions of this specification and of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For more thorough understanding of the present invention and advantages thereof, the following description should be read in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is a schematic view illustrating a configuration of a data input processing system 1 according to an embodiment of the present invention;
[0015] FIG. 2 is a timing chart showing examples of a slow processing signal and a fast processing signal according to an embodiment of the present invention;
[0016] FIG. 3 is a timing chart showing an operation of an input interface 221 when input data is input from a main device 10 according to an embodiment of the present invention;
[0017] FIG. 4 is a timing chart showing an operation of an input interface 221 when a data-output request is made, according to an embodiment of the present invention;
[0018] FIG. 5 is a timing chart showing a temporal relationship among a chip enable signal CE, a data input signal DI that are input from a main device 10 , and output data DO that is output from a multiplexer 226 , according to an embodiment of the present invention;
[0019] FIG. 6 is a schematic view illustrating a configuration of a data input processing system 1 according to an embodiment of the present invention;
[0020] FIG. 7 is a timing chart showing the concrete operation of a data input processing system 1 according to an embodiment of the present invention;
[0021] FIG. 8 is a schematic view illustrating a configuration of a data input processing system 1 according to an embodiment of the present invention;
[0022] FIG. 9 is a timing chart showing an operation of a data input processing system 1 according to an embodiment of the present invention; and
[0023] FIG. 10 is a schematic view illustrating a configuration of a data input processing system 1 applied to car audio systems or the like, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] At least the following details will become apparent from descriptions of this specification and of the accompanying drawings.
[0025] In a data input processing circuit and a controller that are applied to a car audio system, etc. including a main device and a display device separate therefrom, a signal with a long sampling period that is output from a key scanning circuit or a rotary encoder and a signal with a short sampling period that is output from a remote control unit are output to the controller via a small number of signal lines, both the above signals being output from the data input processing circuit included in the display device to the controller included in the main device.
[0026] Outputting a slow processing signal (first digital signal) and a fast processing signal (second digital signal) to the controller by time-division multiplexing, it is possible to output the slow processing signal and the fast processing signal to the controller via a small number of signal lines. Thereby, it is possible to attain simple wiring, to reduce the possibility of a trouble such as a faulty connection, and to reduce manufacturing costs as the result of a reduced number of parts.
First Embodiment
[0027] An embodiment according to the present invention will be explained hereinafter. FIG. 1 illustrates the configuration of a data input processing system 1 that is applied to a car audio system to be explained as an embodiment of the present invention. The data input processing system 1 includes a main device 10 and a display device 20 that is separable from the main device 10 .
[0028] The main device 10 includes mechanisms and circuits to achieve the functions of a car audio system such as a CD or DVD player, a radio receiver, etc. The display device 20 includes a display panel 21 to indicate information on the control or the operation of the car audio system, a data input processing circuit 22 , a key scanning circuit 23 , a rotary encoder 24 , and a remote control receiver 25 .
[0029] In the following explanation, a digital signal with a long sampling period as a signal that is output from the key scanning circuit 23 or the rotary encoder 24 is referred to as a slow processing signal (first digital signal), and a digital signal with a short sampling period as a signal that is output from the remote control receiver 25 is referred to as a fast processing signal (second digital signal). In this embodiment, the sampling period of a slow processing signal is assumed to be 500 μs and the sampling period of a fast processing signal is assumed to be 50 μs (see FIG. 2 ). That is, the sampling period of the slow processing signal by a controller 11 is longer than the sampling period of the fast processing signal by the controller 11 .
[0030] The main device 10 is equipped with the controller 11 for the display control of the display panel 21 and for the reception of signals from the key scanning unit 23 , the rotary encoder 24 , and the remote control receiver 25 . The controller 11 and an input interface 221 are connected by three signal lines. The controller 11 inputs a clock signal CL, a data input signal DI, and a chip enable signal CE to the input interface 221 in the display device 20 via the signal lines for the display control or for the reception of the signals. The controller 11 and a multiplexer 226 are connected by a single signal line, and output data DO is output from the multiplexer 226 to the controller 11 via the signal line.
[0031] The controller 11 is equipped with a synchronous data processing unit 111 to process a slow processing signal and an asynchronous data processing unit 112 to process a fast processing signal, that are input as the output data DO from the display device 20 . The slow processing signal is input to the synchronous data processing unit 111 being synchronized with the clock signal CL. On the other hand, the fast processing signal is input to the asynchronous data processing unit 112 by digital-through, being asynchronous with the clock signal CL. The digital-through means that an input signal is output both without modification in its wave form and without synchronization. The asynchronous data processing unit 112 processes the fast processing signal, that is input by the digital-through, at a sampling frequency equal to or higher than a predetermined sampling period for the fast processing signal (50 μs).
[0032] The data input processing circuit 22 in the display device 20 includes the input interface 221 , a control resister 222 , a display control unit 223 , a signal generating unit 224 , a signal selecting circuit 225 , and the multiplexer (MPX) 226 . The input interface 221 receives the clock signal CL, the data input signal DI, and the chip enable signal CE that are input from the main device 10 , and stores the data, that is input as the input signal DI, in the control register 222 .
[0033] FIG. 3 is a timing chart showing the operation of the input interface 221 when input data is input from the main device 10 . In this case, the data input signal DI includes an address data (adrs 1 ) and the input data. The input data includes, e.g., display data that is described later and flags that are referred to when the multiplexer 226 selects one out of a plurality of fast processing signals.
[0034] FIG. 4 is a timing chart showing the operation of the input interface 221 and the multiplexer 226 when a data-output request is made by the main device 10 . In this case, an address data (adrs 2 ) designating a slow processing signal to be requested to be output, is input as the data input signal DI. The multiplexer 226 then outputs the output data DO corresponding to the address data (adrs 2 ) to the main device 10 .
[0035] The display control unit 223 in the data input processing circuit 22 controls the display panel 21 based on display data that is input as input data from the main device 10 and is memorized at the control register 222 . The signal generating unit 224 provides a drive signal to the display control unit 223 .
[0036] The signal selecting circuit 225 selects a slow processing signal (key scanning signal or rotary encoder detecting signal), that corresponds to the address data (adrs 2 ) that is input from the main device 10 as a data-output request and is memorized at the control register 222 , and outputs the selected slow processing signal to the multiplexer 226 . The signal selecting circuit 225 is a parallel/serial converting circuit, and a slow processing signal is input to the signal selecting circuit 225 as a parallel signal, and the slow processing signal that is output from the signal selecting circuit 225 is input to the multiplexer 226 as a serial signal that is synchronous with the clock signal CL.
[0037] The multiplexer 226 includes a first circuit 226 A that multiplexes a slow processing signal input from the signal selecting circuit 225 and a fast processing signal input from the remote control receiver 25 by time-division multiplexing, and a second circuit 226 B that outputs a time-division multiplexed signal to the main device 10 as the output data DO. The output periods of the slow and the fast processing signals, that include a single frame of the time-division multiplex, can be preset at the multiplexer 226 . Here, the single frame is assumed to be 500 μs, and the output period of the slow processing signal is assumed to be set at 50 μs and the output period of the fast processing signal is assumed to be set at 450 μs.
[0038] FIG. 5 is a timing chart showing the temporal relationship among the chip enable signal CE, the data input signal DI that are input from the main device 10 , and the output data DO that is output from the multiplexer 226 . An address data (adrs 2 ) is first input as the data input signal DI, and thereby, the output request of a slow processing signal is made by the main device 10 . In response to this, a slow processing signal (data 2 ) is output as the output data DO (t 1 to t 2 ).
[0039] An address data (adrs 1 ) and an input data are input from the main device 10 as the data input signal DI (t 3 to t 5 ).
[0040] The address data (adrs 2 ) is input from the main device 10 as the data input signal DI, and thereby, the output request of the slow processing signal is made by the main device 10 (t 6 to t 7 ), and in response to this, the slow processing signal (data 2 ) is output as the output data DO (t 7 to t 8 ).
[0041] The address data (adrs 2 ) is input from the main device 10 as the data input signal DI, and thereby, the output request of the slow processing signal is made by the main device 10 (t 9 to t 10 ), and in response to this, the slow processing signal (data 2 ) is output as the output data DO (t 10 to t 11 ).
[0042] As shown in the figure, the multiplexer 226 outputs a fast processing signal by the digital-through as the output data DO during the period other than the output period for a slow processing signal. That is, the multiplexer 226 outputs the slow processing signal in response to a request from the controller 11 , and outputs the fast processing signal during a period except a period when the slow processing signal is output.
[0043] Thus the data input processing system 1 has a mechanism to transmit a slow processing signal from the key scanning circuit 23 or the rotary encoder 24 and a fast processing signal from the remote control receiver 25 through a single serial signal line by time-division multiplexing. Hence the number of signal lines connecting the main device 10 and the display device 20 can be reduced, and simple wiring is attained. A trouble such as a faulty connection is also diminished, and manufacturing costs are reduced as the result of a reduced number of parts.
[0044] Periods other than output periods for a slow processing signal in time-division multiplexing, i.e., output periods for a fast processing signal by the digital-through can be utilized as periods for data input from the controller 11 to the input interface 221 . For a concrete example, the periods can be utilized as periods for display data input from the controller 11 to the input interface 221 , and thereby, the display data can be efficiently input from the main device 10 to the display device 20 .
[0045] In the case that no output request for a slow processing signal is made by the main device 10 during an output period for a slow processing signal, the output period for the slow processing signal may be utilized to output a fast processing signal. That is, if no request is made to output the slow processing signal from the controller 11 , the multiplexer 226 outputs the fast processing signal during a period when the slow processing signal should be output. Such this mechanism can be realized, for example, in the case that any output request is not made, by inputting the address data (adrs 1 ), that is for changing the setting of the output periods of time-division multiplex, from the controller 11 to the display device 20 , and thereby, changing the output period for time-division multiplex from the multiplexer 226 . With such a mechanism, a fast processing signal can be efficiently output to the controller 11 .
Second Embodiment
[0046] Since a fast processing signal from a remote control receiver 25 is input to a multiplexer 226 only when a remote controller is operated, a fast processing signal does not need to be output unless a fast processing signal is input. Therefore, it is preferred to halt the digital-through output of a fast processing signal in this case, from the viewpoint of the reduction of processing load on and of electric power consumption by the multiplexer 226 .
[0047] By the mechanism explained below, it is attained that a fast processing signal is output from the multiplexer 226 only when there is a signal input from the remote control receiver 25 . FIG. 6 illustrates the configuration of a data input processing system 1 with the mechanism.
[0048] As shown in the figure, in the data input processing system 1 , a remote control signal, that is output from the remote control receiver 25 , is input not only to the multiplexer 226 but also to a signal selecting circuit 225 . On the occasion of the output of a remote control signal from the remote control receiver 25 , a slow processing signal that is synchronizable (hereinafter, referred to as a synchronous signal) by the signal selecting circuit 225 is output. The slow processing signal is, e.g., a signal that shifts between “High” and “Low” states at a frequency that allows sampling by the signal selecting circuit 225 , or a signal at a continuous “High” state for a predetermined period.
[0049] The specific operation of the data input processing system 1 is explained referring to FIG. 7 . As shown in FIG. 6 , a remote control signal that is output from the remote control receiver 25 is also input to the signal selecting circuit 225 .
[0050] As shown in FIG. 7 , a controller 11 inputs an address data (adrs 2 ) indicating that the signal selecting circuit 225 is required to output a remote control signal input from the remote control receiver 25 at a predetermined timing, to an input interface 221 (t 0 to t 1 ). In the case that a synchronous signal is output according to the output of the remote control signal during an output period corresponding to the address data (adrs 2 ), the synchronous signal is output as the output data DO (data 2 ) from the multiplexer 226 to the controller 11 (t 1 to t 2 ).
[0051] When a synchronous signal is input, the controller 11 inputs an address data (adrs 1 ) indicating that the multiplexer 226 is required to start the digital-through output of a remote control signal by time-division multiplexing, to the input interface 221 (t 3 to t 4 ). Thereby, the multiplexer 226 starts the digital-through output of a fast processing signal that is time-division multiplexed with a slow processing signal, at the time t 4 ′ when a chip enable signal CE falls.
[0052] During the period of t 5 to t 6 , the address data (adrs 2 ) designating a slow processing signal to be requested to be output, is input as a data input signal DI, and corresponding to the address data (adrs 2 ), the slow processing signal is output as the output data DO from the multiplexer 226 to the main device 10 (t 6 to t 7 ).
[0053] When the input of a fast processing signal is stopped, the controller 11 inputs an address data (adrs 1 ) indicating that the multiplexer 226 is required to halt the digital-through output of a remote control signal by time-division multiplexing, to the input interface 221 (t 8 to t 9 ). Thereby, the multiplexer 226 stops the digital-through output of the fast processing signal that is time-division multiplexed with the slow processing signal, at the time t 9 ′ when a chip enable signal CE falls.
[0054] Employing the above mechanism, a fast processing signal is output from the multiplexer 226 only when a signal is input from the remote control receiver 25 (third circuit). Thereby, processing load on and power consumption by the multiplexer 226 can be reduced.
Third Embodiment
[0055] In the case, for example, that a plurality of remote control signals are input, or that another fast processing signal such as a USB signal or the like exists, a plurality of fast processing signals may need to be output to a main device 10 depending upon the configuration of a data input processing system 1 . In such the cases, employing the following mechanism for example, the plurality of fast processing signals are output to the main devise 10 through a single signal line for the output data DO.
[0056] FIG. 8 illustrates the configuration of a data input processing system 1 to explain the mechanism. As shown in the figure, in the data input processing system 1 , two remote control signals that are output from two remote control receivers 25 and 26 are input to a multiplexer 226 . As the case in the second embodiment, the remote control signals are also input to a signal selecting circuit 225 .
[0057] FIG. 9 is a timing chart showing the operation of the data input processing system 1 in this embodiment. As shown in the figure, a controller 11 inputs an address data (adrs 2 ) indicating that the signal selecting circuit 225 is required to output a signal from the remote control receiver 25 at a predetermined timing, to an input interface 221 (t 0 to t 1 ). The controller 11 also inputs the address data (adrs 2 ) indicating that the signal selecting circuit 225 is required to output a signal from the remote control receiver 26 at a predetermined timing, to the input interface 221 (t 3 to t 4 ). As the case in the second embodiment, the controller 11 determines if a synchronous signal is output from either the remote control receiver 25 or 26 (third circuit). The controller 11 can determine which remote control receivers a synchronous signal is output from, since one of fast processing signals is designated by the above address data (adrs 2 ).
[0058] In the case that a synchronous signal is output, the controller 11 inputs an address data (adrs 1 ) indicating that a remote control receiver outputting the synchronous signal is required to start the digital-through output of a remote control signal, to the input interface 221 (t 6 to t 7 ). Thereby, the multiplexer 226 starts the digital-through output of a fast processing signal that is time-division multiplexed with the slow processing signal, from the remote control receiver which outputs the synchronous signal, at the time t 7 ′ when a chip enable signal CE falls.
[0059] When the input of a fast processing signal is stopped, the controller 11 inputs an address data (adrs 1 ) indicating that the multiplexer 226 is required to halt the digital-through output of a remote control signal by time-division multiplexing, to the input interface 221 (t 11 to t 12 ). Thereby, the multiplexer 226 stops the digital-through output of the fast processing signal that is time-division multiplexed with the slow processing signal, at the time t 13 when a chip enable signal CE falls.
[0060] Employing the above mechanism, even in the case that a plurality of fast processing signals need to be output to the main device 10 , e.g., such a condition that a plurality of remote control signals are input or that another fast processing signal such as a USB signal or the like exists, a plurality of fast processing signals can be output to the main device 10 through a single signal line for the output data DO.
[0061] In the above embodiments, the number of fast processing signals is not limited as described above but larger numbers of fast processing signals may exist.
[0062] The above embodiments of the present invention are simply for facilitating the understanding of the present invention and are not in any way to be construed as limiting the present invention. The present invention may variously be changed or altered without departing from its spirit and encompass equivalents thereof. The number of slow processing signals is not limited to the above but larger numbers of slow processing signals may exist. | A data processing circuit comprising: a first circuit configured to time-division-multiplex a first digital signal synchronous with a clock signal input from an external controller and a second digital signal asynchronous with the clock signal; and a second circuit configured to output a digital signal time-division-multiplexed by the first circuit to the controller. | 7 |
[0001] The prokaryotic organism Actinoplanes sp. SE50/110 produces the alpha-glucosidase inhibitor acarbose, which is used worldwide in the treatment of diabetes mellitus type-2. Based on the fact, that the incidence of diabetes type-2 is rapidly rising worldwide, an increasing demand for acarbose is expected in the future. In order to meet these expectations, genetic manipulations of the strain and its derivatives have to be carried out, aiming at increasing acarbose yields. However, currently no tools for genetic manipulation exist for this strain, hampering the process of strain improvement.
[0002] The present invention is directed to an innate DNA sequence within the complete genome sequence of Actinoplanes sp. SE50/110 which resembles the structure of an actinomycete integrative and conjugative element (AICE). Related AICEs were used for establishing genetic manipulation tools for other bacteria in the past. In this document, we describe the unique features of the specific AICE found in Actinoplanes sp. SE50/110, which are clearly distinct from any other known AICE as a whole, but share minor parts with varying sequence similarity with other characterized AICEs from other species.
DESCRIPTION OF THE INVENTION
[0003] Actinoplanes sp. SE50/110 is a Gram-positive, aerobic bacterium with a high G+C content genome of about 9.25 MB in size (Schwientek et al., 2012). The medically important organism is the natural producer of a variety of chemically related substances, which were found to inhibit human alpha-glucosidases (Caspary and Graf, 1979), making them especially suitable for pharmaceutical applications (Frommer et al., 1975, 1977 a, 1977 b, 1979). In particular, the pseudotetrasaccharide acarbose, which is synthesized through enzymes encoded in the well characterized acarbose gene cluster (Wehmeier and Piepersberg, 2004), is used worldwide in the treatment of type-2 diabetes mellitus (non-insulin-dependent).
[0004] Diabetes mellitus type-2 is a chronic disease with more than 250 million people affected worldwide. Inappropriately managed or untreated, it can lead to severe cases of renal failure, blindness, slowly healing wounds and arterial diseases, including coronary artery atherosclerosis (IDF, 2009). As the incidence of diabetes type 2 is rapidly rising worldwide, an ever increasing demand for diabetes drugs like acarbose needs to be anticipated. The pseudotetrasaccharide acarbose is currently produced by industrial fermentation of yield-optimized strains, which are based on the wild-type bacterium Actinoplanes sp. SE50/110 (ATCC 31044; CBS 674.73). While classical strain optimization through conventional mutagenesis was a very successful way of increasing the production of acarbose in the past, this strategy seems to have reached its limits by now. In order to further increase production efficacy, targeted genetic engineering methods have to be applied, which requires a functional transformation system for Actinoplanes sp. SE50/110. Previous experiments revealed that Actinoplanes sp. SE50/110 and Actinoplanes friuliensis (and presumably most other Actinoplanes spp.) do not allow for standard transformation methods like electroporation or PEG-mediated transformation, despite serious efforts have been made (Heinzelmann et al., 2003). In this context, an actinomycete integrative and conjugative element (AICE) has been identified on the Actinoplanes sp. SE50/110 genome (GenBank:CP003170), which can be used for this purpose as has been shown previously for related species (Hosted et al., 2005).
[0005] AICEs are a class of mobile genetic elements possessing a highly conserved structural organization with functional modules for excision/integration, replication, conjugative transfer and regulation (te Poele, Bolhuis, et al., 2008). Being able to replicate autonomously, they are also said to mediate the acquisition of additional modules encoding functions, such as resistance and metabolic traits, which confer a selective advantage to the host under certain environmental conditions (Burrus and Waldor, 2004). A new AICE, designated pACPL, was identified in the complete genome sequence of Actinoplanes sp. SE50/110 ( FIG. 1 ). Its size of 13.6 kb and the structural gene organization are in good accordance with other known AICEs of closely related species like Micromonospora rosario, Salinispora tropica or Streptomyces coelicolor (te Poele, Bolhuis, et al., 2008).
[0006] FIG. 1 Structural organization of the newly identified actinomycete integrative and conjugative element (AICE) pACPL from Actinoplanes sp. SE50/110. Typical genes that are also found on other AICEs are colored: excision/integration (orange), replication (yellow), main transfer (dark blue), conjugation (blue), NUDIX hydrolase (dark green), regulation (green), other annotated function (red), unknown function (gray).
[0007] FIG. 2 Scatter plot of 571 Actinoplanes sp. SE50/110 contigs resulting from automatic combined assembly of paired end and whole genome shotgun pyrosequencing runs. The average number of reads per base is 21.12 and is depicted in the plot by the central diagonal line marked with ‘average’. Additional lines indicate the factor of over- and underrepresentation of reads per base up to a factor of 10 and 1/10 fold, respectively. The axes represent logarithmic scales. Large and highly overrepresented contigs are highlighted by special symbols. Each contig is represented by one of the following symbols: diamond, regular contig; square, contig related to the actinomycete integrative and conjugative element (AICE); triangle, contig related to ribosomal operon (rrn); circle, related to transposons.
[0008] Most known AICEs subsist in their host genome by integration in the 3′ end of a tRNA gene by site-specific recombination between two short identical sequences (att identity segments) within the attachment sites located on the genome (attB) and the AICE (attP), respectively (te Poele, Bolhuis, et al., 2008). In pACPL, the att identity segments are 43 nt in size and attB overlaps the 3′ end of a proline tRNA gene. Moreover, the identity segment in attP is flanked by two 21 nt repeats containing two mismatches: GTCACCCAGTTAGT(T/C)AC(C/T)CAG. These exhibit high similarities to the arm-type sites identified in the AICE pSAM2 from Strepomyces ambofaciens. For pSAM2 it was shown that the integrase binds to these repeats and that they are essential for efficient recombination (Raynal et al., 2002).
[0009] Besides the proline tRNA genomic integration site, pACPL was shown to subsist in at least twelve copies ( FIG. 2 ) as an extrachromosomal element in an average Actinoplanes sp. SE50/110 cell (Schwientek et al., 2012). pACPL hosts 22 protein coding sequences.
[0010] The actinomycete integrative and conjugative element of the present invention is selected from the group consisting of:
a) a polynucleotide having the sequence of SEQ ID 1, b) a polynucleotide which hybridizes under stringent conditions to a polynucleotide as specified in (a) and c) a polynucleotide having at least 90% identity with the sequence of SEQ ID 1.
[0014] Preferred are AICEs having at least 95% identity with the sequence of SEQ ID 1. More preferred are AICEs having at least 98% identity with the sequence of SEQ ID 1. The present invention is further related to a host cell that has been transformed with the actinomycete integrative and conjugative element described above. The most preferred host cell is an Actinoplanes sp. The host cell is useful in a method for preparation of biological products comprising the steps of
a) culturing the above host cell in a useful medium, b) harvesting the product from the culture and c) isolating and purifying the product.
[0018] The most preferred product in this method is acarbose.
DETAILED DESCRIPTION OF THE 22 PROTEIN CODING SEQUENCES OF pACPL
[0019] The gene int (genomic locus tag: ACPL — 6310) encodes the integrase of the AICE with a length of 388 amino acids. Its sequence shows 74% similarity to an integrase (GenBank: EFL40120.1) of Streptomyces griseoflavus Tu4000 within the first 383 amino acids. The integrase domain of the protein is located from amino acid 182-365 and shows high similarity (e-value 2.90e-21) to the Int/Topo IB signature motif (conserved domain: cd01182). The integrase is responsible for integration into a tRNA gene by site-specific recombination which occurs between the two similar attachment sites attB on the chromosome and attP on the AICE (te Poele, Bolhuis, et al., 2008).
[0020] The gene xis (genomic locus tag: ACPL — 6309) encodes the excisionase of the AICE with a length of 68 amino acids). It shows highest similarity to the hypothetical protein Sros — 7036 (GenBank: ACZ89735.1) from Streptosporangium roseum DSM 43021. The protein contains a moderately conserved (e-value: 1.31e-07) helix-turn-helix motif (pfam12728) between amino acids 9-55. Xis is needed in combination with Int to mediate the excision of the AICE from the chromosome in preparation for amplification and transfer to other hosts (te Poele, Bolhuis, et al., 2008).
[0021] The gene repSA (genomic locus tag: ACPL — 6308) encodes the replication initiation protein of the AICE with a length of 598 amino acids. It has highest similarity to a putative plasmid replication initiation protein (GenBank: ADL48867.1) from Micromonospora aurantiaca ATCC 27029. The protein resembles the well characterized RepSA protein from Streptomyces ambofaciens which has been found to apply a rolling cycle replication mechanism (Hagège et al., 1993).
[0022] The gene aice1 (genomic locus tag: ACPL — 6307) encodes a protein with unknown function with a length of 97 amino acids. It shows 69% similarity in the first 80 amino acids to the hypothetical protein Micau — 5360 (GenBank: ADL48866.1) from Micromonospora aurantiaca ATCC 27029.
[0023] The gene spdA (genomic locus tag: ACPL — 6306) encodes a putative spread protein of the AICE with a length of 107 amino acids. SpdA shows 54% similarity to a spread protein (GenBank: ABD10289.1) from Frankia sp. CcI3. Spread proteins are involved in pock formation, which reflects a temporary growth delay of recipient cells that are in the process of acquiring an AICE from a donor cell. Thus, spread proteins assist in the intramycelial spread of (Kataoka et al., 1994; Grohmann et al., 2003; te Poele, Bolhuis, et al., 2008).
[0024] The gene spdB (genomic locus tag: ACPL — 6305) encodes a putative spread protein of the AICE with a length of 169 amino acids. SpdB shows 84% similarity between the amino acids 40-131 to a spread protein (GenBank: AAX38998.1) from Micromonospora rosaria. Spread proteins are involved in pock formation, which reflects a temporary growth delay of recipient cells that are in the process of acquiring an AICE from a donor cell. Thus, spread proteins assist in the intramycelial spread of (Kataoka et al., 1994; Grohmann et al., 2003; te Poele, Bolhuis, et al., 2008). A signal peptide has been found for SpdB, its cleavage site is predicted at position 18. Furthermore, three transmembrane helices were found at positions i53-70o75-97i109-131o.
[0025] The gene aice2 (genomic locus tag: ACPL — 6304) encodes a protein with unknown function with a length of 96 amino acids. It shows 57% similarity between the amino acids 12-89 to the hypothetical protein Micau — 5358 (GenBank: ADL48864.1) from Micromonospora aurantiaca ATCC 27029.
[0026] The gene aice3 (genomic locus tag: ACPL — 6303) encodes a protein with unknown function with a length of 61 amino acids. It shows no significant similarity to any of the proteins in public databases.
[0027] The gene aice4 (genomic locus tag: ACPL — 6302) encodes a protein with unknown function with a length of 138 amino acids. It shows 69% similarity in the last 113 amino acids to the hypothetical protein Micau — 5357 (GenBank: ADL48863.1) from Micromonospora aurantiaca ATCC 27029.
[0028] The gene aice5 (genomic locus tag: ACPL — 6301) encodes a protein with unknown function with a length of 108 amino acids. It shows 79% similarity to the complete amino acid sequence of the hypothetical protein Micau — 5356 (GenBank: ADL48862.1) from Micromonospora aurantiaca ATCC 27029. This protein has a low pfam hit (e-value 0.0022) to sigma factors with extracytoplasmic function (ECF). These sigma factors can bind to RNA polymerase in order to stimulate the transcription of specific genes. They are believed to be activated upon receiving a stimulus from the environment and are often cotranscribed with one or more negative regulators (Heimann, 2002).
[0029] The gene aice6 (genomic locus tag: ACPL — 6300) encodes a protein with unknown function with a length of 149 amino acids. It shows 50% similarity to the complete amino acid sequence of the hypothetical protein VAB18032 — 01645 (GenBank: AEB47413.1) from Verrucosispora maris AB-18-032.
[0030] The gene aice7 (genomic locus tag: ACPL — 6299) encodes a protein with unknown function with a length of 66 amino acids. It shows no similarity to any of the proteins in public databases. Aice7 contains a single transmembrane helix ranging from amino acid 9-31.
[0031] The gene tra (genomic locus tag: ACPL — 6298) encodes the main transfer protein of the AICE with a length of 293 amino acids. It exhibits 74% similarity throughout the major part to a cell division protein (GenBank: ADL48859.1) from Micromonospora aurantiaca ATCC 27029. Tra contains a domain with significant similarity (e-value 3.1e-14) to the FtsK/SpollIE domain between amino acids 29-187, which is found in all AICEs and Streptomyces transferase genes (te Poele, Bolhuis, et al., 2008). Several experiments have provided evidence, that homologues of Tra are responsible for the translocation of double-stranded DNA to the recipient strains. Translocation occurs at the hyphal tips of the mating mycelium (Possoz et al., 2001; Reuther et al., 2006).
[0032] The gene aice8 (genomic locus tag: ACPL — 6297) encodes a protein with unknown function with a length of 124 amino acids. It shows 44% similarity between the amino acids 44-116 to the sequence of the FadE6 protein (GenBank: EGT86701.1) from Mycobacterium colombiense CECT 3035. While the complete FadE6 protein has 733 amino acids that resemble an acyl-CoA dehydrogenase, Aice8 is unlikely to have a similar function as it does not contain the catalytic domains of FadE6 and is only 124 amino acids in length.
[0033] The gene aice9 (genomic locus tag: ACPL — 6296) encodes a protein with unknown function with a length of 320 amino acids. It shows 68% similarity throughout the major part of the sequence to the hypothetical protein Micau — 5352 (GenBank: ADL48858.1) from Micromonospora aurantiaca ATCC 27029. This protein contains four transmembrane helices at positions 132-51o57-79i88-110o115-134i.
[0034] The gene aice10 (genomic locus tag: ACPL — 6295) encodes a protein with unknown function with a length of 69 amino acids. It shows no significant similarity to any of the proteins in public databases.
[0035] The gene pra (genomic locus tag: ACPL — 6294) is likely to encode the activator of the repSA, xis and int genes. It has a length of 105 amino acids and shows 90% similarity throughout the complete sequence to the hypothetical protein Micau — 5352 (GenBank: ADL48857.1) from Micromonospora aurantiaca ATCC 27029. Pra, which regulates the transfer and replication of the AICE, is believed to be repressed by the transcriptional regulator KorSA in the AICE pSAM2 from Streptomyces ambofaciens (Sezonov et al., 2000). By repressing Pra, the AICE remains in its integrated from on the chromosome.
[0036] The gene reg (genomic locus tag: ACPL — 6293) encodes a regulatory protein of the AICE with a length of 444 amino acids. It shows 50% similarity throughout the complete sequence to a putative regulator (GenBank: CCB75999.1) from Streptomyces cattleya NRRL 8057. Reg contains a helix-turn-helix domain, ranging from amino acids 4-72. Although the sequence similarity between Reg and KorSA from pSAM2 is very low, the localization of reg between the pra and nud genes may be an indication for Reg resembling a homologue to KorSA, which is frequently found in this genetic organization (te Poele, Bolhuis, et al., 2008).
[0037] The gene nud (genomic locus tag: ACPL — 6292) encodes a protein which contains a NUDIX-hydrolase domain between amino acids 29-144. It has a size of 172 amino acids and shows 72% similarity throughout the sequence to a hypothetical protein (GenBank: EFL09132.1) of Streptomyces sp. AA4 and various NUDIX hydrolases from closely related species. Nud exhibits 42% similarity between amino acids 21-108 to the Pif protein of pSAM2. Pif also contains a NUDIX-hydrolase domain, and was shown to be involved in intercellular signaling, which is believed to inhibit replication and transfer of the AICE in order to prevent redundant transfer between pSAM2 harboring cells (Possoz et al., 2003; te Poele, Bolhuis, et al., 2008). It is therefore likely, that Pra, Reg and Nud in pACPL resemble a similar regulatory mechanism like Pra, KorSA and Pif do for pSAM2.
[0038] The gene mdp (genomic locus tag: ACPL — 6291) encodes a metal-dependent phosphohydrolase with a length of 80 amino acids. It exhibits 66% similarity throughout its sequence to a metal-dependent phosphohydrolase (GenBank: ABD10513.1) from Frankia sp. CcI3. Mdp encoding genes are frequently found in a cluster with pra, reg and nud homologues on other AICEs (te Poele, Bolhuis, et al., 2008). Metal-dependent phosphohydrolases may be involved in signal transduction or nucleic acid metabolism (te Poele, Samborskyy, et al., 2008).
[0039] The gene aice11 (genomic locus tag: ACPL — 6290) encodes a protein with unknown function with a length of 256 amino acids. It shows no significant similarity to any of the proteins in public databases.
[0040] The gene aice12 (genomic locus tag: ACPL — 6289) encodes a protein with unknown function with a length of 93 amino acids. It shows no significant similarity to any of the proteins in public databases.
REFERENCES
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[0042] Caspary, W. F., Graf, S., 1979. Inhibition of human intestinal alpha-glucosidehydrolases by a new complex oligosaccharide. Res Exp Med (Berl) 175, 1-6.
[0043] Frommer, W., Junge, B., Keup, U., Mueller, L., Schmidt, D., 1977. Amino sugar derivatives. German patent DE 2347782 (U.S. Pat. No. 4,062,950).
[0044] Frommer, W., Junge, B., Müller, L., Schmidt, D., Truscheit, E., 1979. Neue Enzyminhibitoren aus Mikroorganismen. Planta Med 35, 195-217.
[0045] Frommer, W., Puls, W., Schäfer, D., Schmidt, D., 1975. Glycoside-hydrolase enzyme inhibitors. German patent DE 2064092 (U.S. Pat. No. 3,876,766).
[0046] Frommer, W., Puls, W., Schmidt, D., 1977. Process for the production of a saccharase inhibitor. German patent DE 2209834 (U.S. Pat. No. 4,019,960).
[0047] Grohmann, E., Muth, G., Espinosa, M., 2003. Conjugative Plasmid Transfer in Gram-Positive Bacteria. Microbiol. Mol. Biol. Rev. 67, 277-301.
[0048] Hagège, J., Pernodet, J. L., Friedmann, A., Guérineau, M., 1993. Mode and origin of replication of pSAM2, a conjugative integrating element of Streptomyces ambofaciens. Mol. Microbiol. 10, 799-812.
[0049] Heinzelmann, E., Berger, S., Puk, O., Reichenstein, B., Wohlleben, W., Schwartz, D., 2003. A Glutamate Mutase Is Involved in the Biosynthesis of the Lipopeptide Antibiotic Friulimicin in Actinoplanes friuliensis. Antimicrob Agents Chemother 47, 447-457.
[0050] Heimann, J. D., 2002. The extracytoplasmic function (ECF) sigma factors. Adv. Microb. Physiol. 46, 47-110.
[0051] Hosted, T. J., Jr, Wang, T., Horan, A. C., 2005. Characterization of the Micromonospora rosaria pMR2 plasmid and development of a high G+C codon optimized integrase for site-specific integration. Plasmid 54, 249-258.
[0052] IDF, 2009. IDF Diabetes Atlas, 4th edn. International Diabetes Federation, Brussels, Belgium: International Diabetes Federation.
[0053] Kataoka, M., Kiyose, Y. M., Michisuji, Y., Horiguchi, T., Seki, T., Yoshida, T., 1994. Complete Nucleotide Sequence of the Streptomyces nigrifaciens Plasmid, pSN22: Genetic Organization and Correlation with Genetic Properties. Plasmid 32, 55-69.
[0054] te Poele, E. M., Bolhuis, H., Dijkhuizen, L., 2008. Actinomycete integrative and conjugative elements. Antonie Van Leeuwenhoek 94, 127-143.
[0055] te Poele, E. M., Samborskyy, M., Oliynyk, M., Leadlay, P. F., Bolhuis, H., Dijkhuizen, L., 2008. Actinomycete integrative and conjugative pMEA-like elements of Amycolatopsis and Saccharopolyspora decoded. Plasmid 59, 202-216.
[0056] Possoz, C., Gagnat, J., Sezonov, G., Guérineau, M., Pernodet, J.-L., 2003. Conjugal immunity of Streptomyces strains carrying the integrative element pSAM2 is due to the pif gene (pSAM2 immunity factor). Mol. Microbiol. 47, 1385-1393.
[0057] Possoz, C., Ribard, C., Gagnat, J., Pernodet, J. L., Guérineau, M., 2001. The integrative element pSAM2 from Streptomyces: kinetics and mode of conjugal transfer. Mol. Microbiol. 42, 159-166.
[0058] Raynal, A., Friedmann, A., Tuphile, K., Guerineau, M., Pernodet, J.-L., 2002. Characterization of the attP site of the integrative element pSAM2 from Streptomyces ambofaciens. Microbiology (Reading, Engl.) 148, 61-67.
[0059] Reuther, J., Gekeler, C., Tiffert, Y., Wohlleben, W., Muth, G., 2006. Unique conjugation mechanism in mycelial streptomycetes: a DNA-binding ATPase translocates unprocessed plasmid DNA at the hyphal tip. Mol. Microbiol. 61, 436-446.
[0060] Schwientek, P., Szczepanowski, R., Rückert, C., Kalinowski, J., Klein, A., Selber, K., Wehmeier, U. F., Stoye, J., Pühler, A., 2012. The complete genome sequence of the acarbose producer Actinoplanes sp. SE50/110. BMC Genomics 1-2.
[0061] Sezonov, G., Possoz, C., Friedmann, A., Pernodet, J. L., Guérineau, M., 2000. KorSA from the Streptomyces integrative element pSAM2 is a central transcriptional repressor: target genes and binding sites. J. Bacteriol. 182, 1243-1250.
[0062] Wehmeier, U. F., Piepersberg, W., 2004. Biotechnology and molecular biology of the alpha-s glucosidase inhibitor acarbose. Appl. Microbiol. Biotechnol 63, 613-625. | The present invention is directed to an innate DNA sequence within the complete genome sequence of Actinoplanes sp. SE50/110 which resembles the structure of an actinomycete integrative and conjugative element (AICE). Related AICEs were used for establishing genetic manipulation tools for other bacteria in the past. In this document, we describe the unique features of the specific AICE found in Actinoplanes sp. SE50/110 which are clearly distinct from any other known AICE as a whole, but share minor parts with varying sequence similarity with other characterized AiCEs from other species. | 2 |
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/925,972 filed on Nov. 3, 2010, which is a continuation-in-part of U.S. application Ser. No. 12/798,415 filed on Apr. 2, 2010, which is a divisional of U.S. application Ser. No. 11/010,598 filed on Dec. 13, 2004, now U.S. Pat. No. 7,712,637 which claims the benefit of U.S. Provisional Application No. 60/528,565 filed Dec. 11, 2003, the entire teachings of these applications being incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates generally to the dispensing or extracting of fluids from within containers and finds particular utility in the dispensing and preservation of wine.
2. Summary of the Invention
The field of the invention includes devices and methods for extracting fluids from within containers.
An object of one or more embodiments of the invention is to allow a user to withdraw a volume of liquid from within a container that is sealed by a cork, plug or elastomeric septum without removing the cork, septum or closure device. It is a further object of one or more embodiments of the invention to allow removal of liquid from such a container repeatedly without causing enough damage to the cork that either gas or fluid exchange through the cork is possible under standard storage conditions. It is a further object of one or more embodiments of the invention to ensure that no gas which is reactive with the liquid passes into the container either during or after extraction of fluid from within the container.
Various embodiments of the invention enables the user to withdraw wine from within a wine bottle without removal of, or damage to the cork that would allow undesired gaseous or liquid egress or ingress during or after extraction of wine.
One embodiment of the invention involves at least one or more needle, valve, and source of pressurized gas. The needle is connected to the valve which is in turn connected to the source of pressurized gas. The needle is passed through the cork or between the cork and an interior wall of the bottle until it makes contact, at a minimum, with the interior of the bottle beyond the cork. Prior to or following insertion of the needle, the bottle is positioned such that the liquid content of the bottle can contact at least a portion of the needle. The valve is then opened such that pressurized gas can pass through the needle into the interior of the bottle. The valve is then switched to a position preventing further ingress of gas while allowing the liquid contents of the bottle to be expelled from the bottle through the needle by the pressurized gas now within the bottle. Once a desired amount of liquid content has been removed from the bottle, the bottle is then repositioned such that the pressurized gas content of the bottle is in contact with at least a portion of the needle so that the gas may be expelled from the bottle until there is no or an acceptably low pressure differential between the bottle and atmosphere. The needle is then removed from the cork.
In a preferred embodiment, the needle is a smooth exterior walled, cylindrical needle with a non-coring tip that can be passed through the cork without removing any material from the cork. The preferred non-coring tip is a pencil-tip that dilates a passageway through the cork, although deflected-tip and stylet needles have also been found to work and could be used in alternative embodiments. The pencil-tip needle preferably has at least one lumen extending along its length from at least one inlet on the end opposite the pencil-tip and at least one outlet proximal to the pencil-tip. The preferred outlet is through the side-wall of the needle.
With the correct needle gauge, it has been found that the passageway that remains following removal of such a needle self-seals against egress or ingress of fluids and gasses under normal storage conditions. While multiple needle gauges can work, preferred needle gauges range from 16 to 22 gauge, with the optimal needle gauge being between 17 and 20 gauge. These needles gauges offer optimal fluid flow with minimal pressures while doing an acceptably low level of damage to the cork even after repeated insertions and extractions.
Multiple needle lengths can be adapted to work within the scope of the present invention, however it has been found that a minimum needle length of 1.5 inches is required to pass through standard corks. Needles as long as 9 inches could be employed, but the optimal range of length has been found to be between 2 and 2.6 inches. The needle may be connected to the valve directly through any standard fitting (e.g. NPT, RPT, Leur, quick-connect or standard thread) or alternatively may be connected to the valve through an additional means such as a flexible or rigid tube. When two or more needles are used their lengths may be the same or different and vary from 0.25 inches to 10 inches. Creating distance between the inlet/outlets of the needles can prevent the formation of bubbles.
While many standard valves could be employed, two are of particular utility for this application. The first is a three-way trumpet or spool valve. Such valves have a piston which slides within a cylinder. The piston is moved downward into the cylinder by the user depressing a button connected to or integral to the piston. The piston is moved upward by a return spring in contact with the piston. When the piston is depressed by the user, a first passageway through the cylinder allows passage of gas from a pressurized gas source connected to the valve at the “gas connection” into the needle connected to the valve at the “needle connection”. Gas is allowed to enter the bottle through the needle until the user decides to release the piston. When the piston is released by the user, the spring pushes the cylinder upward exposing a second passageway through the cylinder which allows passage of the pressurized content in connection with the needle to pass through the cylinder to a “valve exit”. This valve exit may, for example be a simple hole positioned above a glass or may be a tube leading to a secondary container. This process may be repeated until a desired amount of liquid is removed from the bottle. The user then positions the bottle such that pressurized gas within the bottle is in contact with at least one outlet of the needle. With the valve cylinder released, pressurized gas can then vent from the bottle through the needle connection and out of the valve exit until a desired final pressure is reached. The needle is then removed from the cork.
The second advantageous valve is an automatic, pressure regulated valve. The primary function of this valve is to maximize the rate of liquid content egress through the needle by automatically maintaining an optimal pressure range within the bottle. A secondary function of such a valve is to control the final pressure within the bottle just prior to removal of the needle from the cork. Such a valve could be operated by a user through the use of a toggle between two valve positions—extract and vent. In the extract position a passage between the pressurized gas source and the needle would be opened by the valve until a desired maximum pressure limit is achieved within the bottle. The valve would then automatically switch to the vent position wherein a passageway is opened between the needle and a valve exit so that contents of the bottle can be expelled. The valve would then automatically switch back to the extract position when a lower pressure limit was reached. This process continues until a desired amount of the liquid content of the bottle is extracted. The bottle is then positioned such that the gaseous contents of the bottle are in contact with at least a portion of the needle allowing gas to exit in the vent position prior to extraction of the needle. The lower pressure limit could be changed for this gas-venting procedure to allow a final/controlled pressure within the bottle. This changing of the lower pressure limit could be achieved automatically through the use of a switch that is activated by the tilting of the bottle (e.g. when the bottle is standing upward the switch would be activate the lower pressure while when the bottle is on its side the switch would activate the higher pressure.)
Other valves that could be used include, but are not limited to ball, solenoid, pivoted-armature, rotating cylinder, and toggle valves. Additional valves could further be added to the system. For example, a simple two-way check valve placed at the wine exit could be employed to maintain pressure within the bottle without flow of wine. In this way, wine can be released from the bottle at the users discretion after pressurization.
It has been found that the maximum value for the upper pressure limit is between around 40 and 50 PSI but is optimally between around 15 and 30 PSI. These pressures are well tolerated by even the weakest of cork-to-bottle seals. The lower pressure limit during wine extraction could be between 1 and 20 PSI lower than the upper pressure limit. For example, selecting an upper pressure limit of 30 PSI, it has been found that a lower limit of 15-20 PSI maintains an adequate pressure gradient to ensure rapid expulsion of wine through a 17 to 20 gauge needle. The final/controlled pressure (the lower of the lower pressure limits) can be between 0 and 15 PSI, with an optimal range of 0 to 5 PSI.
The source of pressurized gas can be any of a variety of regulated or unregulated pressurized gas containers filled with a variety of non-reactive gasses. In a preferred embodiment, the source consists of a container of gas with the gas at an elevated initial pressure (2000-3000 psi). This container is then regulated to the desired outlet pressure by either a fixed or variable regulator. This regulator can be any of a variety of single or two stage regulators available on the market. This configuration allows the use of conveniently small bottles of compressed gas that contain relatively large quantities of gas capable of emptying many bottles of wine. It further insures that the outlet pressure of the valve is maintained as the pressure within the container of gas changes during use. Multiple gasses have been tested successfully over extended periods of time, but the preferred gasses are nitrogen and argon. Preferably the gas is non-reactive with the fluid within the subject vessel such as wine and can otherwise protect the fluid from the deleterious effect of air infiltration or exposure. Nitrogen has the advantage of being very inexpensive and readily available in a variety of container sizes and initial pressures. Argon has the advantage of being a completely inert, noble gas as well as being heavier-than-air. By being heavier-than-air, argon minimizes the risk of inadvertent ingress of reactive atmospheric gasses during the final venting of the pressurized gas from within the container. Other non or minimally reactive gases or mixtures thereof also work, for example helium and neon. Preferably, the gas used should be equal to or greater in weight than air to prevent ingress of unwanted gasses and should have a low permeability through cork and/or glass, all resulting in helium being less preferred. Mixtures of gas are also possible. For example, a mixture of argon and another lighter gas would blanket the wine in argon while the lighter gas would occupy volume within the bottle and perhaps reduce the overall cost of the gas. Preferred embodiments use disposable membrane cylinders of nitrogen or argon at storage pressures equal to or greater than 2500 psi and a simple regulator set at a fixed outlet pressure between 15 and 30 PSI.
An alternative source of gas that allows greater volumes to be stored in smaller containers is a liquid that changes phase to gas and expands once released from its container.
In one exemplary embodiment a device is provided that has a hollow needle having an inlet at one end and an outlet at a second end and wherein the needle is adapted to penetrate beyond a closure device (such as a cork, plug, or septum) sealing a container; a pressurized source of gas; a pressure regulator capable of reducing the pressure of the gas from the pressurized source to a lower pressure at a regulator outlet, wherein the regulator is connected to the pressurized source at a regulator inlet; a valve secured at a first valve inlet to the regulator outlet, secured at a first valve outlet to the needle inlet, and having a second valve outlet for the passage of gas or fluids from within the container; and wherein the valve controls the flow of gas from the pressurized source into the container through the needle and the flow of gas or fluid from within the container through the needle and out of said valve outlet.
In one exemplary method fluid can be extracted from within a container sealed by a closure device by inserting the outlet of a single lumen, non-coring needle with a smooth exterior wall beyond the closure device and into the container; injecting a pressurized non-reactive gas into the container through the hollow needle thereby causing an increase of pressure within the container to a level higher than the surrounding atmospheric pressure; allowing the fluid within the container to be forced out of the container by this pressure through the needle until a desired amount of fluid is extracted; and then removing the needle from the closure device thereby allowing the closure device to reseal.
Other components can be added to the system to increase its functionality or durability. Of particular utility include a linear drive mechanism, a container attachment mechanism, a sealing member retention means, and an anti-buckling mechanism.
A linear drive mechanism is any mechanism that forces the needle to be inserted into and through the closure device or between the closure device and container in a linear path. This can help to prevent buckling of the needle due to side loads or bending moments. This system could be as simple as a single keyed rod passing through a matching keyed hole wherein the rod's travel through the hole is along a line co-linear with the desired needle path. This rod can be connected directly to the needle or to an intervening device. Further embodiments could include multiple cylindrical rods that pass through multiple closely matching round holes or tubes that are co-linear with the desired needle path, among others.
A container attachment mechanism is any mechanism capable of securing or stabilizing at least a portion of the device to the container. This can serve the purpose of again reducing the risk of buckling of the needle by ensuring that the needle path stays fixedly relative to the container. It can also aid in preventing inadvertent withdrawal of the needle from the container. It can further be used in concert with a cork or sealing member retention means to prevent expulsion of the sealing member from the container during pressurization. An attachment mechanism can provide an anchoring location that would give such a sealing member retention means the stability necessary to hold the sealing member in place during pressurization. For example, such a retention means could comprise a surface of the device that contacts a surface of a sealing member outside of the container and, when secured to the container by an attachment mechanism, could obstruct the path that the sealing member must travel to be expelled from the container. Suitable attachment mechanisms can include, but are not limited to, two clamping arms that close about a portion of the container. For example, in the case of a wine bottle, these two clamp arms could close about the neck of the bottle. An attachment mechanism could alternatively involve glue, Velcro, threaded attachments that are driven into a wall of the container, suction cups, tape, and the like. The attachment mechanism could additionally have a releasable lock that acts to releaseably secure the device to the container. In the case of the clamp arms, such a lock could include a simple threaded bolt that passes through both arms and has a nut on one end that can be threaded down the bolt to apply varying clamping force to the container and then be unthreaded to release the container.
An anti-buckling mechanism is any mechanism that acts to reduce the risk of the needle buckling during insertion and withdrawal of the needle. Apposing arms that contact the sides of the needle's length are one possible embodiment of such a mechanism. The arms could have a slot running through a surface of the arm. This slot could be as wide and deep as the needle diameter. As the needle is advanced into the sealing device, these slots would act to resist buckling of the needle by restraining bending of the needle due to contact between the needle length and the walls of the slot, giving the needle the opportunity to bend only toward the opening of the slot. Apposing arms could meet at an angle to create unlikely buckling paths offset by this angle. 90 degrees has been found to be a particularly effective angle. Other anti-buckling mechanisms are possible and include, but are not limited to, telescoping cylinders along the needle's length, a collapsible sleeve or bellows that supports the needle at various points along its length, a stiff coiled spring that contacts the needle along its inner diameter, or a single sliding cylinder that contacts the needle at the mid-point of the needle's exposed length outside of the sealing means during insertion and withdrawal.
Various exemplary embodiments of the device are further depicted and described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an embodiment comprising a pencil tip needle connected to a 3-way toggle valve which is in turn connected to a variable regulator connected to a compressed gas cylinder. A wine bottle that has been accessed by the device is also shown in the Figure. Note that the foil 742 covering the corked opening of the bottle is still intact and has not been removed but that small needle hole perforation at an insertion point 740 is shown.
FIG. 2 depicts a cross section of a preferred embodiment of the present invention. The embodiment consists of a cylinder of compressed gas, a fixed pressure regulator, a valve, a needle, and a linear drive mechanism. Details of this embodiment and its use are depicted in FIGS. 2A-E .
FIG. 2A is an exploded view of the three-way spool valve used in this embodiment.
FIG. 2B depicts the valve in its normal position which allows flow between the valve exit and the needle.
FIG. 2C depicts the valve in its activated position which allows flow between the needle and the regulator.
FIG. 2D depicts the linear drive mechanism attached to the needle with the linear drive mechanism at its upward most position.
FIG. 2E depicts the linear drive mechanism attached to the needle with the linear drive mechanism at its downward most position.
FIG. 3A depicts the embodiment positioned on the bottle with the needle positioned over the wine bottle cork and the linear drive mechanism at its upward most position.
FIG. 3B depicts the linear drive mechanism at its downward most position with the needle tip driven through the cork and into the interior of the bottle.
FIG. 3C depicts the system shown in 3 B with the bottle tilted on its side causing the needle tip to come in contact with the liquid contents of the bottle.
FIG. 3D depicts the system of 3 C with the valve activated causing gas at a pressure regulated by the fixed regulator to enter the bottle through the needle, increasing the pressure within the bottle.
FIG. 3E depicts the system of 3 D with the valve returned to its normal position, enabling the increased pressure within the bottle to drive wine through the needle and out of the valve exit.
FIG. 3F depicts the bottle returned to an upright position allowing excess gas from within the bottle to contact the needle tip and vent through the valve exit until the pressure equilibrates with atmospheric pressure.
FIG. 3G depicts the system shown in FIG. 3F with the needle withdrawn from the bottle and the linear drive mechanism at its upward most position.
FIG. 4 is a side view of an alternative embodiment further comprising an anti-buckling mechanism that resists buckling of the needle as it is advanced into the bottle. It further employs a trumpet valve, a linear drive mechanism comprising a linear drive shaft and gear, and a container attachment or bottle clamping mechanism.
FIG. 5A and FIG. 5B depict detail of a preferred embodiment of the anti-buckling mechanism. FIG. 5A shows a front view of a swing arm and indicates a swing arm slot which fits over a section of the needle length to resist buckling. FIG. 5 B depicts two swing arms and their relationship to each of two swing arm axes and the needle.
FIG. 6 depicts an embodiment of the invention shown in block diagram format having two needles.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention is shown in FIG. 1 . This system uses a pressurized source of gas 100 regulated by a variable regulator 600 . The cylinder 100 is secured to the pressure regulator 600 by a simple threaded connection. This embodiment employs a 3-way toggle valve 300 allowing both extract and vent positions described above. This system also uses a pencil-tip non-coring needle 200 with a needle outlet along the side of the needle length near the needle tip. The connection between the valve 300 either the regulator 600 or needle is shown to be rigid. Alternatively these connections could be flexible if desired.
Additional components of a preferred embodiment of the present invention may include:
a bottle attachment or clamping mechanism securing the needle to the bottle,
a linear needle drive system to facilitate insertion of the needle into the bottle along a linear path,
a needle guide that allows insertion of the needle through a particular region of the cork,
an anti-buckling means to minimize the risk of the needle buckling during insertion,
a cork retention means that acts to prevent cork expulsion during pressurization,
a bottle stand that facilitates holding and/or tilting of the bottle during the extraction and venting phases,
a pressure meter that allows the user to know the pressure within the bottle and/or the exit pressure of the gas source,
a needle protection means or lock preventing inadvertent injury of the user by the needle once it is withdrawn from the bottle.
Multiples of these components could be combined into single parts or components serving multiple functions. For example, the anti-buckling means could also serve as a needle protection means, the cork retention means and the needle guide could be combined into a single unit secured to the bottle at the exterior of the cork, and this needle guide/cork retainer could further be a part of the bottle clamping means that may be further combined with the linear needle drive.
FIG. 2 depicts a cross section of a preferred embodiment of the present invention. The embodiment consists of a cylinder of gas 100 connected to a regulator 600 which is in turn connected to a valve 300 . This valve 300 is then secured to a needle 200 . The needle 200 and/or the valve 300 are secured to a linear drive mechanism 400 . The pressure within cylinder 100 is preferably considerably higher than the outlet pressure of the regulator 600 . Regulator 600 is shown without detail, but can be any of a variety of commercially available single or two stage pressure regulators capable of regulating gas pressures to a pre-set or variable outlet pressure. The connection of the various components is not depicted in detail, but can be achieved through either rigid (threaded, welded, taper lock etc.) means or flexible (tubing, o-ring seal, gasket seal) means. The length of such a connection can be varied depending upon the specifics of the desired application.
FIGS. 2A-C detail a preferred embodiment of a three-way, spool valve 300 that has been found particularly useful to control the flow of wine and gas. The valve 300 consists of a piston 310 and a valve body 305 . The piston 310 employs three o-rings—an upper 312 , middle 313 , and lower 314 —to control the flow of fluids and gasses through the valve cylinder 301 .
In FIG. 2B , the upper 312 and lower 314 o-rings are sealing against the inner walls of the valve cylinder 301 , allowing flow between the needle attachment site 303 and the wine exit 304 . In this position, flow between the gas entrance 302 and the other two ports is prevented by the lower o-ring 314 . This is the normal state of the valve with the return spring 311 holding the cylinder in this position. This is the “vent” position described above which, for convenience, will be referred to as B-C.
In FIG. 2C , the upper 312 and middle 313 o-rings are sealing against the inner walls of the valve cylinder 301 , allowing flow between the gas entrance 302 and the needle attachment site 303 . Flow between the wine exit 304 and the other two ports is prevented by o-ring 313 in this position. This is the “extract” position described above which, for convenience, will be referred to as A-B. The user achieves this valve position by pushing down on piston 310 compressing the return spring 311 . Once the user stops depressing the valve piston 310 , the return spring 311 causes the piston to return to position B-C depicted in FIG. 2B .
FIGS. 2D and 2E detail an embodiment of a linear drive mechanism 400 . In this embodiment, two cylindrical rods (front rod 410 and back rod 420 ) pass through two closely matching rod holes (front rod hole 460 and back rod hole 470 ). These two rods are securely attached to upper piece 430 which is also secured to needle 200 . The offset of the two rods creates a resistance to angulations of or side loads on needle 200 by providing a resistive moment. This insures that the needle 200 can travel into and out of a cork only along a line co-linear with the rods.
A flat has further been cut onto the front surface of front rod 410 . This flat acts in concert with rod stop 450 to restrict the upward travel of the needle 200 relative to the bottom piece 440 when stop surface 415 on front rod 410 engages rod stop 450 . This method could also be used to limit downward travel of the needle 200 relative to bottom piece 440 . FIG. 2D illustrates the needle 200 at full upward travel while FIG. 2E illustrates the needle 200 at full downward travel relative to bottom piece 440 .
During use, the needle guide 480 and its through hole 485 are positioned above the cork of a wine bottle and are secured to or part of bottom piece 440 . In this embodiment, the needle guide 480 could be used as a cork retainer if a bottle clamping mechanism is incorporated into bottom piece 440 . Such a bottle clamping mechanism has been left out of this embodiment to detail the other components of the system, but could readily be added. Various embodiments of such a clamping mechanism are described below in alternate embodiments.
FIGS. 3A-3G illustrate the use of the embodiment depicted in FIG. 2 and detailed in FIGS. 2A-E . In FIG. 3A , the bottom piece 440 has been placed on top of wine bottle 700 with the upper piece 430 at full upward travel. The valve is in its normal position B-C. The wine 710 and gas 720 within the bottle 700 are in their undisturbed state as bottled by the vintner. FIG. 3B depicts the needle outlet 220 beyond cork 730 and within bottle 700 with the upper piece 430 at full downward travel. This position is achieved by simply pushing downward on valve 300 or upper piece 430 . The valve 300 is still in its normal B-C position.
In FIG. 3C , the bottle has been tilted on its side, causing wine 710 to contact the needle outlet 220 . In FIG. 3D , the valve has been moved by the user into its A-B position, allowing pressurized gas 120 from within cylinder 100 to pass through the regulator 600 at its upper pressure setting, through gas entrance 302 , through needle attachment 303 , out of needle outlet 220 into wine 710 within the bottle 700 . This gas 120 increases the pressure within the bottle until it reaches equilibrium with the gas pressure determined by the regulator 600 . In FIG. 3E , the valve 300 has been allowed to return to its normal state B-C, opening a path between the needle outlet 220 and the wine exit 304 . The wine 710 is now driven by the elevated pressure of the gasses 720 and 120 within the bottle through the needle outlet 220 and out of valve 300 . This flow will continue until pressure within the bottle equilibrates with atmospheric pressure if the user wishes. However, excess pressure can be allowed to vent by simply standing the bottle upright, as depicted in FIG. 3F . Once the bottle is upright, the gasses 720 and 120 within the bottle are in contact with the needle outlet 220 and can vent from valve 300 with the valve in its normal position B-C. Once the pressure has reached a desired level, the needle can be withdrawn from the cork 730 by pulling upward on the upper piece 430 or valve 300 until the upper piece reaches its upward most travel. The bottom piece 440 and the rest of the system can then be removed from bottle 700 .
It has been found that corks accessed by such a system, particularly with a smooth walled exterior, pencil point or Huber point needle of 16 gauge or higher, seal effectively and prevent the ingress or egress of gases or fluids and can be stored in the same way as an un-accessed bottle for years without abnormal alteration of the wines flavor. Other needle profiles and gauges are also usable with the system.
In the above described embodiment, the needle guide through hole 485 is depicted over the center of the cork 730 . Alternatively, the through hole 485 could be offset from the center of cork 730 to decrease the potential that multiple uses of the system will allow the needle to pass through the same site in the cork.
An alternative embodiment is depicted in FIG. 4 . This embodiment employs an alternate linear drive system, a bottle clamping mechanism, a different configuration of 3-way spool or trumpet valve, and an anti-bucking mechanism.
FIG. 4 illustrates a side view of this exemplary embodiment in a multi-component, assembled fashion. On the upper left the figure is a cylinder of compressed gas 100 attached to a regulator 600 . Below the regulator 600 is a trumpet valve 300 . Below valve 300 are the needle 200 , anti-buckling assembly 800 , linear drive mechanism 400 , needle guide and cork retention means 480 , and bottle clamp 500 . The regulator 600 of this embodiment is a variable regulator. It has a simple threaded attachment to the compressed gas cylinder 100 . The trumpet valve 300 is attached to the regulator 600 through a simple Luer connector. The valve 300 is actuated by depressing the piston 310 shown in FIG. 4 . This valve 300 is a simple trumpet or spool valve. With the piston 310 in the un-depressed position, the valve 300 is opened such that fluid can flow from the needle 200 and out of the valve exit 304 (position B-C or vent position). When the piston 310 is depressed, gas can flow from the regulator 600 through the needle 200 (position A-B or extract position).
The linear drive mechanism 400 of this embodiment consists of a steel shaft or front rod 410 and gear 490 toward the bottom of the figure. The front rod 410 passes through a closely matching hole 460 in lower piece 440 . Gear 490 is a rack and pinion system wherein when the circular gear turns, the gear teeth mesh causing the needle to be driven downward into the cork or upward out of the cork depending upon the rotational direction of the circular gear.
The clamp mechanism 500 and the anti-buckling mechanism 800 . The anti-buckling system 800 comprises two steel rods 810 and seven swing arms 820 pivoting about rods 810 . Each swing arm has a proximal end with a through hole for the steel rod 810 and a small slot cut at their opposite end which fits over the needle 200 along its length. Each steel rod 810 acts as an axis about which the arms 820 swing. Each arm's slot opposes the neighboring arm's slot. These opposite facing slots act to entrap the needle 200 and prevent it from buckling along 270° of the circumference of the needle at any one arm 820 . Because the slots oppose each other, it is highly unlikely that the needle 200 can buckle along a length greater than the length of any individual slot.
Even along one slot, the needle 200 can only buckle in the direction that the slot is open, eliminating the risk of buckling along 270° of the needle circumference. These axes 810 are spaced from each other such that alternate swing arms meet at an angle. A particularly preferred angle of intersection of the swing arms is 90°, but a range between 45 and 135 is also acceptable. By alternating the swing arms 820 in this fashion the needle slot of each swing arm 820 has an opening that is offset by roughly 90 degrees from its neighboring swing arm 820 . This radically reduces the risk of needle 200 buckling as the ability to buckle in any single plane is eliminated. The needle 200 can only buckle along any one length supported by any one swing arm 820 in the direction that the needle slot is open. As the tendency to buckle is strongly dependent upon the free length available to buckle, the risk of buckling is exponentially lower than an unprotected needle. A particularly useful swing arm slot length has been found to be less than 0.5 inches for needles within the preferred gauge range of 17 to 20 with a particularly useful length being 0.25 inches. The slot width and depth preferably closely matches the diameter of the needle used.
In this embodiment, the needle 200 moves through the anti-buckling mechanism 800 as it is advanced into the bottle's cork. As the needle 200 moves, a small taper on the needle's hub 240 pushes the swing arms 820 outward allowing the needle 200 to pass. There is also an elastic band 830 which acts to return the swing arms 820 to the needle 200 after they have been moved aside by the needle hub 240 or the hub extenders 250 . This elastic band 830 essentially acts as a return spring. The extended needle hubs 250 , depicted here as white cones, guide the swing arms 820 around the needle hub 240 and its larger base at the upper piece 430 without catching any edge due to the force of the elastic band 830 . Alternative embodiments of the anti-buckling mechanism might include a series of telescoping cylinders, a single sliding cylinder, a collapsible bellows that makes contact with the needle at the narrowest diameter of the bellows, or a stiff coiled spring making contact with the needle diameter at the spring's inner surface.
The bottle clamping mechanism 500 consists of two simple clamping arms 510 and a locking mechanism comprised of a screw 520 and nut 530 to secure the arms 510 at a fixed position. Each clamp arm swings about an axis 540 . This clamping mechanism 500 also ensures that the cork is centered beneath the needle 200 and that the needle guide and cork retaining system rests atop the bottle cork or sealing means.
A combined needle guide and cork retaining system 480 is shown as a simple disk with a small hole equal to or greater in diameter than the needle diameter that passes through its center. When the clamping mechanism 500 is secured to the bottle 700 , this component 480 preferably rests against the upper surface of the cork as depicted in FIG. 4E . As this component 480 is fixed in position relative to the clamping arms 510 , it acts to secure the cork in position during pressurization of the bottle.
FIGS. 5A and 5B depict further detail of the anti-buckling mechanism 800 shown in FIGS. 4 . FIG. 5A shows a front view of a swing arm 820 with a slot 840 running along one end. FIG. 5B shows how this slot 840 fits over a length of the needle 200 . In this figure, the swing arm 820 on the left constrains the needle 200 within slot 840 . The swing arm 820 on right has swung away from the needle 200 about axis 810 . When both swing arms 820 are engaging the needle 200 , the needle is constrained such that the risk of needle buckling is reduced. By using multiple, alternating swing arms, the needle can be protected against buckling during advancement into and through a cork.
Alternative embodiments of the device might be integral to a bottle stand. In this embodiment there may be no need for a bottle clamp. The bottle could simply be slid along the bottle stand into the needle and anti-buckling mechanism. In this fashion the bottle would be on its side during insertion of the needle better guaranteeing contact between the needle tip and the fluid within the bottle. After use, the stand could be pivoted upward to allow the gas to vent.
In still further embodiments there might be more than one needle. Two needles would allow insertion of gas and extraction of fluid at the same time. One needle would be dedicated to allowing ingress of gas and would be connected to the pressurized gas source, while the other needle would allow the extraction of wine or fluid from within the bottle. Such an embodiment is shown in FIG. 6 . In such an embodiment there may be no need for the trumpet valve described above, but simply for an on-off switch for the pressurized gas source. The needles can have the same or different diameters or the same or different length varying from 0.25 to 10 inches. For example, one needle delivering gas could be longer than another that extracts wine from the bottle. This could also be achieved with a two lumen needle wherein gas would travel down one lumen and wine would travel up the other. Each lumen could have a separate entrance and exit. These exits could be spaced from each other within the bottle to prevent circulation of gas.
Still further embodiments may employ a dilator instead of a needle. Such a dilator could be passed between the cork and the bottle wall into the wine, leaving no damage to the cork itself. Such a dilator could be cannulated and arcuately shaped to best match the outer diameter of the cork.
The bottle clamping mechanism employed in the above described embodiments comprises two clamping handles pivoting around axes secured to the bottom piece. These handles are lockable to the wine bottle through the use of a clamp bolt/screw and nut. Many alternative embodiments of a bottle clamp are possible. Alternatives to the bolt and nut lock include, but are not limited to a ratcheting lock, or a simple strap that can be slid down or wrapped around the swing arms, locks located at the axes of the swing arms, etc. The clamp handles could be replaced by a cylinder that fits over the wine bottle neck. Such a cylinder could have a split wall with a conically tapered outer surface. An outer ring could be slid along the conical surface to cause the inner diameter of the cylinder to decrease, clamping the cylinder about the bottle neck. A locking feature between the ring and the cylinder could be used to lock the cylinder to the bottle. This cylinder could be incorporated into the bottom piece.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | Devices and methods are disclosed for extracting fluids from within a container sealed by a cork or septum without removal of the cork or septum or the contamination of the fluid within the container by reactive gases or liquids. Embodiments of the device can include a needle connected to a valve which is in turn connected to a source of pressurized gas for displacing the fluid. Further embodiments of the device can comprise additional components that act to force the needle to be inserted through the cork or septum along a linear path, to aid in preventing buckling of the needle, to clamp the device to the container, to prevent expulsion of the cork or septum from the container, and to guide the needle through a specified region of the cork or septum. Various valves, pressure regulators, pressure ranges, needle geometries, gas selections are also presented. This device is particularly suited for the dispensing and preservation of wine. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending application Ser. No. 11/325,271 filed Jan. 3, 2006 entitled LIGHT FIXTURE AND LIGHTING METHOD, which in turn claims the benefit of U.S. Provisional Application No. 60/641,243 filed Jan. 3, 2005 entitled LIGHT FIXTURE AND LIGHTING METHOD.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a light fixture, and more particularly to a light fixture suited for use in size-restricted areas, such as for example in lighting an aquarium or a plant bench, and which can provide light of greater intensity than many conventional fixtures, including a standard linear fluorescent fixture, and a method of providing lighting.
[0003] Many types of light fixtures are available for providing artificial light in connection with a number of diverse activities. These conventionally use various types of light sources, including incandescent, fluorescent, metal halide and sodium lamps. Each of these light sources have particular advantage and disadvantage, and selection of a particular type is dependent in large part on the desired application. For example, incandescent bulbs can be dimmed, but are the least light efficient, generating greater heat and less light per watt consumed than the remaining type lamps. Metal halide and sodium lamps require a ballast to operate. Magnetic ballasts, which can generate noise, are generally required, at present, for larger output bulbs. Fluorescent bulbs, while having greater efficiency than incandescent bulbs, cannot be dimmed.
[0004] Often, the level of light and spectral range emitted is the factor of greatest importance to a user. Particularly in the fields of aquaria and horticulture, wherein photosynthetic processes are involved, selection of a type of light is predicated upon production of sufficient levels of light intensity within a usable spectrum. While fluorescent lights, which are readily available and relatively inexpensive to buy and operate, and which output light in a spectral range usable in photosynthesis, they have heretofore not generally provided a sufficient level of light required by many plants and simulated reef environments. For this reason, metal halide lighting, while much more expensive that fluorescent lighting, is generally the lighting of choice for many applications requiring high intensity light.
[0005] Compact fluorescent bulbs are available, which are intended for replacement of less efficient incandescent bulbs, and which have an integral ballast and, optionally, a standard screw base. These bulbs can, according to present design, emit up to about four times the amount of light than a standard incandescent bulb using the same power, and therefore, because of their greater light efficiency, run much cooler while outputting comparable levels of light of other types of lighting sources. However, a light fixture for housing these lights has heretofore not delivered a suitable intensity of light for many applications.
[0006] It would therefore be desirable to provide a light fixture that could utilize any light source, including fluorescent, in a manner which increases the light provided thereby.
[0007] Accordingly, it is an object of the invention to provide a light fixture which overcomes the drawbacks of the prior art.
[0008] It is a further object of the invention to provide a light fixture in a compact size suitable for use in defined spaces, and which would maximize light density.
[0009] It is an additional object to provide a light fixture in a form that is economical and functionally versatile.
[0010] It is still a further object of the invention to provide a light fixture in which light elements can be installed easily for exchange or replacement, and which optionally accepts compact fluorescent bulbs having a standard incandescent type screw base.
[0011] It is yet a further object of the invention to provide a method of replacement or exchange of light bulbs in a fixture.
SUMMARY OF THE INVENTION
[0012] In accordance with these and other objects of the invention, there is provided a light fixture in which individual light bulbs are arranged in compact fashion to maximize the number of bulbs per given area in the fixture. The lights are movable from a use orientation to another, bulb replacement position in which the bulbs are accessible for hand replacement.
[0013] Briefly stated, a light fixture includes at least one support to which light bulbs or other light sources are mountably receivable. When installed to the support, the lights are energizable from a power source to emit light in a desired direction, for example, downward, when in a use orientation. The support is movable from the use orientation to a service orientation in which the bulbs are hand-accessible for replacement or substitution by a user. Advantageously, the support is supportably mounted to a suitable retaining structure in both orientations, and more advantageously continuously remains supportably mounted to the retaining structure also while moved between the respective orientations.
[0014] According to an embodiment of the invention, a light support is pivotably mountable to a supporting structure, provided, for example, in the form of a housing, and which is conveniently adapted for mounted support to a retaining structure. The light support with lights installed is suitably oriented in one retained position to the supporting structure for active use in providing light, i.e., a use orientation, and is rotatable from such use orientation to a service orientation while remaining mounted to the supporting structure. The lights may be simply arranged along a single row or, alternatively, plural rows, with all of the lights of a given row being disposed codirectionally. Alternatively, and more advantageously, individual lights can be arranged in a row, the lights being directed along respective mutually parallel planes running crosswise the row of lights, adjacent ones of the lights being positioned at an angle to one another, whereby such angularly offset arrangement provides greater accessibility to the lights for facilitated hand replacement notwithstanding a laterally close arrangement.
[0015] In accordance with another embodiment of the invention, in order to facilitate replacement or exchange of the bulbs, while concomitantly conveniently allowing the bulbs to be placed in a tightly-packed arrangement when in use, the individual bulbs are mounted in alternating succession on a pair of supports, at least one of which is movable independently of the other, reorientation of which serves to remove the bulbs from the tight packed arrangement, to one in which the bulbs on the respective supports are sufficiently separated from one another to allow facilitated hand access for removal and installation of the bulbs.
[0016] In accordance with an embodiment of the invention, a light fixture conveniently employs a pair of optional access panels, advantageously, though not necessarily, provided in the form of hinged doors, located more advantageously in an upward facing position of the fixture when oriented for use in emitting light in a downward direction, to allow access to the bulbs from above, rather than below, as in most, if not all, enclosed conventional fixtures designed to project light downwardly. The light bulbs (also referred to interchangeably herein as “light elements”) are mounted to inwardly facing sides of respective ones of the doors, such that when the doors are opened upwardly (or panels removed, when not hingably mounted), each door (or panel) includes at least one of the bulbs mounted thereto, and which are made accessible by such movement. After replacement or exchange, the doors are returned to the closed position, thereby restoring an advantageously, but not necessarily, closely packed bulb arrangement, and preventing excessive upward escape of light.
[0017] In a particularly advantageous embodiment, a fixture in accordance with the invention utilizes self-contained, high efficiency output, compact fluorescent lights of the conventional type mentioned above, and which each have their own integral ballast, located generally between a base adapted for screw connection to a socket and the light emitting portion thereof. The bulbs are arranged with bases of alternate bulbs facing in a horizontal direction, or having a horizontal vector when arranged in a vertically tilted orientation, opposed to that of an adjacent bulb. A pair of supports, advantageously embodying at least one door, is provided at a top of the fixture Each bulb facing in one of the directions is mounted to one of the supports, and each bulb facing in the opposite direction is mounted to a remaining one of the supports, such that the bulbs are arranged in alternating fashion between one another, and extend in a sideways direction of the light fixture when supports are oriented in a use position.
[0018] Whether or not equipped with an access from above to bulbs contained in the fixture, as hereinbefore described, a distinct feature of the invention, providing independent advantage from the features mentioned above, includes an optional configuration allowing use of the fixtures as plural light emitting sources. Such feature has particular advantage in use, for example, in applications requiring greater light intensity over an extended defined region of given area, such as in connection with aquariums, terrariums, hydroponics and agriculture. Additionally, use of plural (two or more) fixtures allows selection of different bulbs for each fixture to suit, perhaps, different needs over different regions illuminated thereby. In a particularly advantageous embodiment, the light fixtures optionally include electrical coupling structure for transmitting power from one fixture to another connected therewith, thereby allowing multiple fixtures to be connected one to the other, and requiring only one to be powered directly to an external power outlet.
[0019] While virtually any light source can be used in the above described arrangements, use of compact fluorescent light elements is considered particularly advantageous, since each light can be selected to emit a desired spectrum of light for a given application. Additionally, since each light has its own ballast, the fixture is light weight, maintenance-free, and lights of different wattage can be freely substituted without requiring a change in ballast, as would be otherwise required in a fixture utilizing standard fluorescent bulbs.
[0020] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 a is a cross-sectional view taken along line 1 a - 1 a of FIG. 2 of a light fixture according to an embodiment of the invention, depicted in a use orientation;
[0022] FIG. 1 b is a cross-sectional view of the embodiment of FIG. 1 a , depicted in a service orientation;
[0023] FIG. 2 is a bottom plan view of the embodiment of FIGS. 1 a and 1 b depicted in the use orientation;
[0024] FIG. 3 is a bottom plan view of another embodiment of the invention depicted in a use orientation;
[0025] FIG. 4 a is a cross-sectional view taken along line 4 a - 4 a of FIG. 3 in the use orientation;
[0026] FIG. 4 b is a cross-sectional view of the embodiment of FIG. 4 a depicted in the service orientation;
[0027] FIG. 5 is a top plan view of another embodiment of a light fixture in accordance with the invention;
[0028] FIG. 6 a is a cross-sectional view taken along line 6 a - 6 a in FIG. 5 ;
[0029] FIG. 6 b is a cross-section view taken along line 6 b - 6 b in FIG. 7 b;
[0030] FIG. 7 a is plan view of the light fixture of FIG. 5 , shown with one of a pair of access doors moved to a bulb replacement position;
[0031] FIG. 7 b is plan view of the light fixture of FIG. 7 a , shown with both doors moved to respective bulb replacement positions;
[0032] FIG. 8 is a perspective view of the light fixtures shown in FIGS. 5-7 b , depicted with the access doors closed to a use oriented position;
[0033] FIG. 9 is a perspective view depicting an embodiment employing a series of light fixtures according to the invention used atop an aquarium;
[0034] FIG. 10 is a front elevational view of another embodiment employing plural light fixtures according to the invention for use in lighting a reptile terrarium;
[0035] FIG. 11 a is a plan view of another embodiment of a light fixture in accordance with the invention shown in condition of operation; and
[0036] FIG. 11 b is a plan view of the embodiment of FIG. 11 a depicted in an opened condition for servicing of the light elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] Referring now to the figures, and in particular FIGS. 1 a , 1 b and 2 , a light fixture in accordance with an embodiment of the invention is shown, generally at 10 . Light fixture 10 includes a housing 1 , and which optionally includes a light transmissive panel 2 through which light is directed generally in the direction of the arrows shown in FIG. 1 a . Light sockets 3 for receiving light elements 4 are mounted to a rotatable support 5 that is pivotably received to the housing 1 for rotatable positional reorientation about a pivot axis A. A reflector 6 is advantageously provided to focus or increase the intensity of light directed in the desired direction, and as appropriately indicated by the desired application. It is noted that details of internal wiring within fixture 1 , as well as external powering of the fixture 1 , are omitted from the figures for simplifying illustration, and as being deemed unnecessary since the electrical configurations to be employed are well within the purview of one of ordinary skill in the art.
[0038] FIGS. 1 a and 1 b depict, respectively, a use orientation and service orientation. In particular, as shown in FIG. 1 a (and FIG. 2 ), the light elements 4 are vertically positioned for light emission in a downward direction. When the light elements 4 require replacement, or alternatively, exchange of the light elements 4 is desired, for example, to alter a spectral output, the rotatable support 5 is rotated about pivot axis A to the service orientation shown in FIG. 1 b . In this position, the light elements 4 are exposed above the housing 1 and can be readily accessed by the user. When servicing is complete, the rotatable support 5 is pivoted back to the use position of FIG. 1 a.
[0039] Advantageously, suitable structure is optionally provided that allows retained positioning in two discrete orientations corresponding respectively to the aforementioned use and service orientations. In the depicted example, shown essentially in simplified schematic form, this feature is provided conveniently in the form of a rest 7 and a stop 8 which engage edges of the rotatable support 5 to prevent rotation thereof past a roughly 180 degrees range of travel.
[0040] Referring now to FIGS. 3 , 4 a and 4 b , another embodiment of a light fixture is depicted generally at 20 . While having a different shape than the previous embodiment, the overall functioning of the present embodiment is analogous with that of FIGS. 1 a , 1 b and 2 . Light fixture 20 includes a housing 21 , which also optionally includes a light transmissive window 22 which, while having a curved, rather than planar, configuration, corresponds in function and advantage to panel 2 of the previous embodiment. Light sockets 3 for receiving light elements 4 are mounted to a rotatable support 25 that is pivotably received to the housing 21 for rotatable positional reorientation about a pivot axis A′. A reflector 26 is also optionally and advantageously provided.
[0041] FIGS. 4 a and 4 b depict, respectively, a use orientation and service orientation, the further description of which is omitted as duplicative of the analogous description relating to the functioning of the previous embodiment of FIGS. 1 a , 1 b and 2 . However, it is noted that the embodiment differs in the fact that light sockets 3 are mounted in an alternating angularly offset manner such that adjacent light elements are tilted at an angle α with respect to one another. Such feature further facilitates access to individual light elements 4 during servicing.
[0042] Turning now to FIGS. 5-8 , a light fixture in accordance with another embodiment of the invention is shown, generally designated 30 . Light fixture 30 includes a housing 31 , and which optionally includes a light transmissive panel 32 through which light is directed generally in the direction of the arrows shown in FIG. 6 a . Light sockets 3 for receiving light elements 4 are mounted to a pair of supports that are engageable with the housing 31 in a suitable manner as to allow reorientation with respect to, or removal from, the housing 31 to allow installation or substitution of the light elements 4 , as will be explained below. While the arrows indicative of light rays transmitted through light transmissive panel 32 are shown as being parallel in FIG. 6 a , it will be understood that the beam of light alternatively can be divergent or convergent depending on the nature (curvature) of a reflector 36 disposed behind the light bulbs.
[0043] The aforementioned supports for receiving the light elements 4 are provided in the present embodiment conveniently in the form of a first door 35 and a second door 36 , both hingably mounted to the housing 31 to allow pivotable movement about respective axes A 1 and A 2 . The reflector 36 is conveniently mounted to first door 37 . The second door 38 is mounted inward of the first door 37 such that the first door 37 partially overlaps the second door 38 when the light fixture 30 is closed, in the use position, as shown in FIGS. 5 , 6 a and 8 . When installed, light elements 4 advantageously extend codirectionally with a width direction of the fixture 10 , i.e. orthogonal to a direction of light emission from the fixture, or, as shown in FIGS. 6 a and 6 b , at a slight tilt from a horizontal plane, to minimize a required height of the fixture 10 . The light elements 4 can, however, be oriented in any suitable orientation if height is not a particular issue, for example vertically, with bases of the light elements 4 facing opposite to the direction light transmitted from the light fixture 30 . In the depicted example, four sockets 3 are provided for receiving up to four light elements 4 , wherein two of the sockets 3 are mounted to the first door 37 and the remaining two of the sockets are mounted to the second door 38 . It will be understood, however, that any number of sockets 3 and light elements 4 (odd or even) can be installed to a light fixture 30 of suitable length.
[0044] In the depicted embodiment of FIGS. 5-8 , the light elements 4 are arranged with bases of alternate light elements 4 facing in a direction roughly opposed to that of an adjacent one of the light elements 4 . However, the direction of the light elements 4 need not be reversed with each successive light element, i.e., every other light element, but instead, for example, could be reversed every two light elements, i.e. alternating pairs, or a combination of either pattern or other patterns.
[0045] As mentioned above, the second door 38 is mounted inward of the first door 37 such that the latter advantageously overlays a portion of the second door 38 when the light fixture 30 is in a closed, light illuminating orientation, as shown in FIGS. 5 , 6 a and 8 . Therefore, while the first door 37 in the outer position can be a full panel, the second door must be suitably configured to provide suitable clearance to allow the sockets 3 carried on the first door 37 (and light elements 4 installed therein), to be received between the other light elements 4 and sockets 3 carried on the second door 38 .
[0046] When the light elements 4 are to be replaced, the first and second doors 36 , 37 are opened as shown in FIGS. 6 b and 7 b . The intermediary step of initially opening the first door 37 is shown in 7 a . When the light elements 4 have been replaced, the light fixture 30 is returned to a closed, use position ( FIGS. 5 , 6 a and 8 ) by reversing the above steps. To further facilitate opening of the first door 37 , a finger cutout 37 a can optionally be provided as shown in FIG. 8 .
[0047] Power is supplied to the fixture 30 by a power cord 35 . A particularly advantageous option is to provide the power cord as a removable (cheater) cord which couples to a male plug 39 external of the fixture 30 . The advantage of such feature will be apparent from the description which follows pertaining to a further embodiment.
[0048] Whether or not equipped with an access from above to bulbs contained in the fixture, as hereinbefore described, a distinct feature of the invention providing independent advantage from those pertaining to placement and reorientation of the light elements in a fixture is directed to an optional configuration allowing use of the fixtures as plural light emitting sources. Such feature has particular advantage in use, for example, in applications requiring greater light intensity over an extended defined region of given area, such as in connection with aquariums, terrariums, hydroponics and agriculture.
[0049] An example of such plural arrangement is depicted, for example in FIG. 9 , and in which a plurality of light fixtures 30 of the general design as shown in FIGS. 5-8 are placed in adjacent positions atop an aquarium 41 . Unlike standard fixtures of conventional design which are dimensioned to extend along a longitudinal direction of an aquarium tank, and which are generally supported by resting engagement of opposed ends of the fixture with the top edge of either side end of the aquarium, the feature of the present invention instead provides a dimension of the fixtures 30 which allows the fixtures to extend front to back of the aquarium 41 , wherein the fixtures are supported on the top edges corresponding to the front and back walls of the aquarium. Suitable dimensioning of the fixtures 30 will advantageously allow a length extent of the aquarium to be subdivided into an appropriate number of fixtures, the latter which can then be placed atop the aquarium 41 to collectively extend over a substantial length portion of the aquarium, for example, as depicted in FIG. 9 .
[0050] In a particularly advantageous variation, the light fixtures 30 of FIG. 9 optionally include electrical coupling structure for transmitting power from one fixture to another connected therewith, thereby allowing fixtures to be connected one to the other, and requiring only one to be powered directly to an external power outlet. As previously mentioned in connection with FIGS. 5-8 , power is advantageously supplied to the fixture 30 by a power cord 35 which removably couples to a male plug 39 external of the fixture 30 . Referring back to FIGS. 4-8 , and as best seen in FIGS. 5 and 8 , fixture 30 further includes a female connecter 49 positioned such that it aligns with male plug 39 of an adjacent fixture 30 when power cord 35 is removed. Such feature allows the following operation of adjacently abutted fixtures 30 , as shown in FIG. 9 . When the leftmost fixture 30 of FIG. 9 is powered by power cord 35 , power is transferred to the female connector on the opposite side of the fixture 30 (the position of which is seen in the rightmost fixture 30 which is identical in construction) by suitable internal wiring (not shown). The aligned male plug 39 of the middle fixture 30 plugs into the female connector 49 of the leftmost fixture 30 , and the male plug 39 of the rightmost fixture 30 in turn plugs into the female connector of the middle fixture. Power is therefore transferred from fixture to adjacent fixture, obviating the need for individual power cords for each of the plurality of fixtures.
[0051] In addition to the above advantages associated with a modular arrangement of two or more fixtures, use of plural (two or more) fixtures allows selection of different bulbs for each fixture to suit different light requirements over different regions illuminated thereby. For example, as shown in the embodiment of FIG. 10 , two light fixtures 30 ′ and 30 ″ received atop a terrarium enclosure 41 ′ have different light elements (not shown) installed therein selected to emit light of the type desired to meet environmental light requirements for reptile husbandry. In the depicted example, light fixture 30 ′ contains light elements designed to emit light in the ultraviolet range for basking animals in order to meet metabolic requirements for vitamin D production, and light fixture 30 ″ is equipped with heat lamps to selectively create a temperature gradient along a longitudinal extent of the terrarium enclosure 41 ′ to aid digestion when the reptile is under the light fixture 30 ″ by raising body temperature.
[0052] It is noted that a light fixture within the broad embrace of the contemplated invention can be designed to accommodate virtually any type of light having any size or configuration. For example, while the above embodiments are directed to light elements of compact shape and having a standard screw base, the invention can be also practiced in a fixture adapted for use with linear fluorescent tubes. In such instance, the individual tubes would be mounted on separate supports, at least one of the supports being movable with respect to the remaining support such that the tubes could be placed side by side with minimal space therebetween during use, and reoriented to a service orientation in which the tight packed arrangement of the light tubes on the respective supports would be relieved.
[0053] While, as noted above, virtually any light source can be used in the above described arrangements, use of compact fluorescent light elements is considered particularly advantageous, since each light can be selected to emit a desired spectrum of light for a given application. Additionally, since each light has its own ballast, the fixture is relatively light weight, virtually maintenance-free and permits lights of different wattage to be freely substituted without requiring a change in ballast, as would be otherwise required in a fixture utilizing standard fluorescent bulbs.
[0054] Furthermore, while the above-described embodiments each involves some form of pivotable movement of a light element receiving support relative to a housing, any type of movement can be employed without departure from the invention. For example, as shown in FIGS. 11 a and 11 b , a light fixture is depicted, generally designated 50 , in which slidable movement is employed.
[0055] As depicted, light fixture 50 includes a housing 51 having an optional light transmissive panel 52 , and a pair of slidably movable supports provided in the form of drawers 53 and 54 to which light sockets 3 are mounted for receiving light elements 4 . FIGS. 11 a and 11 b show, respectively, use and service orientations. As shown in FIG. 11 b , by moving drawers 53 , 54 in opposed directions indicated by the arrows, light elements 4 are brought out of a tight packed arrangement, from the use orientation of FIG. 11 a , and exposed from the housing for hand replacement in the service orientation, in analogous fashion with the other embodiments described herein. Handles 53 a , 54 a are optionally provided to facilitate movement of the drawers 53 , 54 .
[0056] It is noted that, in accordance with an advantageous embodiment of the invention, the light elements are optionally exposed to a region of the housing other than that corresponding the light transmissive panel, thereby obviating removal of the panel, and allowing the panel to be readily sealed in a waterproof or water resistant fashion to the housing. Such feature provides particular advantage when used for gardening and aquarium applications, where water presents a potential threat to the internal workings of the fixture.
[0057] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A light fixture allows individual light bulbs to be arranged in compact fashion to maximize the number of bulbs per given area in the fixture. To facilitate replacement or exchange of the bulbs, the bulbs are mounted in alternating succession on a pair of separately movable supports, reorientation of which serves to remove the bulbs from the tight packed arrangement, to one in which the bulbs are sufficiently separated from one another to allow hand access for removal and installation of the bulbs. A distinct aspect of the aforementioned feature of the invention independent of the movable supports resides in the ability to utilize two of more of the fixtures to multiply the light produced. Advantageously, the fixtures can be arranged in direct physical series, side by side, or to form an array extending in orthogonal directions. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a container for shaping and molding materials. More particularly, the present invention relates to a pan designed to create various shapes or molds of a particular material.
2. Description of the Prior Art
Cooking pans have been designed to mold cooking edibles into conventional shapes, such as square, rectangle and circle designs. Molded material, even when in conventional shapes is often difficult to remove. Some pans have been improved to include removable walls to assist removal of a baked product. Acknowledging the fact that molding baking materials was very time consuming, some companies reverted to using baking pans with removable walls. A baking pan assembly is illustrated by U.S. Pat. No. 4,644,858 (1987, Liotto et al.). The baking pan is designed to have removable sides and bottom. The circular half sections are pinned or clamped together at the ends holding a circular base that fits in an annular groove. After the food product is baked, the half sections are detached from the base to expose the product. Another pan with removable sections is illustrated with a multiple-purpose cake pan by U.S. Pat. No. 5,537,917 (1996, Schiffer et al.). The cake pan has a removable insert that slides out from the outer rim of the cake pan. A tube cake insert molds the inner hole of a tube cake. Unfortunately, these pans may only be used for circular shapes. The baking pans do not address baking multiple pieces or even unconventional shapes.
Some pans have been improved to include removable walls to vary the width of the pan. A multi-purpose baking pan with hinged end sections and cover is illustrated by U.S. Pat. No. 5,779,080 (1998, Corse). The pan has a rectangular bottom with two linear sidewalls on opposite edges along the long sides of the rectangular bottom. Two end members are at the short sides of the rectangular bottom having rod-like hinge pins. The pan is also illustrated having a rectangular pan and a divider for varying the size of the two areas. The pan is only good for varying the portions of the two rectangular sections. The pan does not address unconventional shapes or molding more than two sections.
Other pans have been improved to include surface contours to mold distinctive shapes in one or more of the pan walls. A method of making controlled heating baking pan is illustrated by U.S. Pat. No. 5,094,706 (1992, Howe). The pan may be made to have distinctive surface contours pressed or formed on the wall portions for molding designs in the materials.
Repetition in molding or forming multiple pieces is labor intensive and cost consuming. To mold or shape materials, the material must be cut into the desired shape before or after cooking or setting the materials. For example, a baker uses cookie cutters to cut dough before baking the cookies or cuts a triangular slice of circular pizza pie after baking a circle shape. Forming the material to the desired shape takes skill and time, whereas cutting the material creates undesired waste. Some companies have manufactured multiple molding units to save time. A baking pan having multiple baking units is illustrated by U.S. Pat. No. 4,941,585 (1990, Hare et al.). The problem with the prior art multiple unit baking pans is that the material must be measured out and poured into each mold separately. This process is slow and labor intensive. Additionally, the manual method of measuring out the material seldom provides uniform pieces. Furthermore, these multiple unit baking pans have the same repeating shape and the pan must be inverted to remove the material from the pan.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an apparatus that is capable of molding and forming multiple, uniform or variable pieces within one assembly. It is another object of the present invention to provide an apparatus that enables the removal of the finished goods without inverting the apparatus, which may cause damage to the goods. It is still another object of the present invention to provide a device that allows high packing density of odd shapes. It is yet another object of the present invention to provide a device that is fully capable of being broken down to improve the effectiveness of cleaning and to reduce storage space. It is yet another object of the present invention to provide an apparatus that is capable of being used in a conventional or microwave oven. It is yet another object of the present invention to provide an apparatus that is capable of producing goods with uniform shapes and thickness. It is yet another object of the present invention to provide an apparatus that is capable of inserting a stick or handle to the material being molded or baked prior to baking/molding.
The present invention achieves these and other objectives by providing a device that is capable of shaping and molding material. The present invention is an apparatus for shaping and molding material comprising two sidewalls, two end walls, a bottom plate and one or more partitions. The inside surface of the two sidewalls has one or more grooves or slots spaced along the inside surface at predetermined intervals. One of the side walls, i.e. the first sidewall, has one or more surface portions on its inside surface and the inside surface of the other side wall, i.e. the second sidewall, has at least one more surface portion than the inside surface of the first side wall. For example, if first sidewall has two surface portions, then second sidewall has at least three surface portions. The sidewalls also have a bottom ledge or shelf extending out from the inside surface. Additionally, the sidewalls have one or more apertures or holes positioned adjacent to the grooves or slots that extend through the given side wall where the aperture(s) or hole(s) is located. For example, a hole may be placed between two adjacent grooves or between a groove and the end wall.
The end walls are removably attached between the ends of the sidewalls. The connection between a side wall and end wall may be attached using a pinned connection, a latch, band, tongue and groove, etc. The bottom plate has a side edge that conforms to the inside surface of the sidewalls. For example, if the inside surface of the sidewalls had multiple arc shapes, then the bottom plate would conform to those arc shapes. One or more partitions are used to divide the material in the pan into smaller shapes. A given partition is sized to slide into the grooves or slots between the two sidewalls. The partition may be single piece for sliding into two opposed grooves or the partition may be a single, continuous piece formed to slide into a multiple of opposed grooves so that only one partition is used to make a plurality of product pieces. If more than one partition is used, two partitions may be inserted into one groove creating a triangular effect between the sidewalls. The partitions may be single-walled or double-walled. The double-walled design may help distribute heat to the material in the pan that requires cooking such as a cake. The double-walled design is also helpful when cooling the material in the pan when chilling is required such as when making flavored gelatin or molding ice cream and the like.
The bottom plate may be flat, indented to form a “character face” or other design, or have inverted domes that align with the partitions and grooves to create a one-half cone shape. The present invention may also include a bottom support. The bottom support prevents the bottom plate from dropping when disassembling the pan.
The sidewalls may have multiple embodiments. For instance, one embodiment may have a sidewall with an array of notches spaced at predetermined intervals with a top plate that has an array of matching protrusions spaced at the same predetermined intervals as the notches. Mating of the notches and protrusions of the sidewall and the top plate forms the apertures previously mentioned. This arrangement allows removal of the finished unit on a stick by first removing the top plate, end walls, then pulling out the sidewalls and removing the stick from the notch. A block attached to the top plate may also be sized for plugging the notches not needed in a given arrangement. A second embodiment would also have the notches and protrusions, however, the sidewall is a two piece sidewall where each piece has matching inside surfaces.
In one embodiment of the present invention the apparatus also includes a lid section that may be placed over the pan, resting on the sidewalls and end walls. The lid is used to cover the material in the pan for shaping the material. Additionally, the lid aids in stacking multiple pans, one on top of the other. Stacking increases the efficiency when baking goods in a commercial oven. The lid may also include one or more design shaping molds affixed to one side. When the lid is placed over the material being shaped or molded, the design-shaping mold on the lid presses into the material. This mold on the lid adds ornamental designs to the surface of the material. The lid section may also include one or more apertures. A stick or handle to hold the molded piece may be added by inserting it through the aperture in the lid. Once the molded piece is set, the stick is affixed to the material providing the handle.
The device may also include one or more handles attached to one or more of the side walls, the first end wall, the second end wall, the bottom plate, or the partition pieces. Handles may be shaped like a cylindrical rod, a U-shaped bar, a plate structure, etc. The handles make it easier to assemble or disassemble the pan and to remove the finished product.
Another embodiment of the present invention may further comprise an inside surface that has one or more shaping contours spaced adjacent to the grooves. The shaping contours may include, but is not limited to, an arch shape design, tree shape design, etc. In addition, if an arch shape design is used, the arch shape may have a radius that is substantially equal to a given partition. Arch shape designs may be arranged so that the final product looks as if the pieces were cut from a circle.
Another embodiment includes a pivot between the walls to assist in assembly and disassembly of the pan. In this arrangement the first end wall is pivotally attached to one end of a sidewall. The second end wall may also be pivotally attached to the end of a sidewall. When the pan is disassembled, the end walls would remain attached to the sidewalls with the pivots. When reassembling the pan, the end walls are rotated into place against the opposite sidewall and then latched at that end to complete the assembly of the pan. The pivot minimizes the time and skill required reassembling the pan.
To prevent the bottom plate from dropping during disassembly of the pan, another embodiment provides a bottom plate comprising a first section that conforms to the inside surface of the side walls and a second section that is substantially the same thickness as the bottom ledge of the side walls. The first section is removably attached to the second section. In the alternative, the bottom plate may comprise a first section that conforms to the inside surface of the sidewalls and a second section that is greater than the thickness of the bottom ledge of the sidewalls. This way the first section is also removably attached to the second section, but the second section extends under the sidewalls to add further stability to the pan.
Another embodiment of the present invention may further provide the aperture in the sidewall designed so as to accommodate at least one elongated holding member. The elongated holding member may include, for example, a stick, a rod, a handle, a bar, a tube, etc. The holding member may be made from a variety of different materials, for example, wood, metal, ceramic, plastic, etc. Additionally, the side wall thickness is designed to hold the elongated holding member at a fixed angle or parallel to the bottom plate when inserted through the aperture and into the material. One or more of the apertures may also be sized to match at least one elongated holding member. For example, the aperture may be designed to match the holding member by having a shape of a square, a rectangle, a triangle, a circle, a star, a polygon, a crescent, an oval and the like.
When an aperture is not required and holding members are not desired in the material, a plug sized to fit into the apertures may be used. Thus, an aperture may be plugged when a holding member is not placed in a given aperture.
To use the pan after assembly, one would start by spreading or pouring a material into the pan. After evenly spreading the material, at least one partition is inserted into the pan by sliding the partition into two opposed notches in the sidewalls. By pushing the partition until it contacts the bottom of the pan, the material is separated into portions. As many partitions may be inserted into the pan as there exists opposing grooves. It should be noted that the partitions need not be the same shape. Finally, one or more sticks are inserted through a similar number of apertures in the sidewalls and into the material. An alternative is to insert the sticks through the apertures before adding the material to the present invention.
After the partitions and sticks have been inserted in the pan, a lid may be placed over the pan. This would allow the pans to be stacked and protect the finished goods. Stacking pans optimizes the use of space whether on a table, counter, or an oven, refrigerator or baker's shelves. The lid may also have at least one opening to allow placing at least one elongated holding member through the lid into the material or mixture. The holding member may be placed through apertures in the sidewalls and/or in the lid. This option allows the design of a piece being set to have a holding member hold the piece in a vertical or horizontal plane. The lid may also have at least one design-shaping mold affixed to the inside portion of the lid that would be pressed into the mixture. Character features and other designs may be placed in the material being set.
Further objects and advantages of this invention will be more clearly apparent during the course of the following description, references being had to the accompanying drawings which illustrate a preferred form of the device of the invention and wherein like characters of reference designate like parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an apparatus for shaping and molding material that is constructed in accordance with the present invention.
FIG. 2 is a perspective, exploded view of the apparatus in FIG. 1 .
FIG. 2A is a perspective view of the present invention showing a lid.
FIG. 2B is a cross-sectional view of the aperture portion of the present invention showing a plug in the aperture.
FIG. 3 is a cross-sectional view of the present invention showing a holding member held in place through an aperture in the sidewall.
FIG. 4 is a cross-sectional view of one embodiment of the bottom plate of the present invention.
FIG. 5 is a cross-sectional view of another embodiment of the bottom plate of the present invention.
FIG. 6 is a perspective view of another embodiment of the sidewall of the present invention having two sections that form the apertures when assembled.
FIG. 7 is a perspective view of another embodiment of the side wall of the present invention having two sections where one section is a top plate with downwardly extending blocks.
FIG. 8 is a perspective view of various embodiments of the partitions used in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, references will now be made to the preferred embodiment of the present invention as illustrated in FIGS. 1-7, and specific language used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. The terminology used herein is for the purpose of description and not limitation. Any modifications or variations in the depicted method or device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring now to FIG. 1, there is shown a perspective view of a container or pan 10 having a first side wall 20 , a second side wall 30 , a first end wall 40 , a second end wall 50 , and a bottom plate 60 . Container 10 is arranged so that the sidewalls 20 and 30 are opposite each other. Sidewalls 20 and 30 have partition channels 26 at spaced intervals along their inside surfaces 24 . Inside surface 24 of sidewall 20 has one or more surface portions 24 ′. Inside surface 24 of sidewall 30 has one more surface portion 24 ′ than the number of surface portions 24 ′ on sidewall 20 . First end wall 40 and second end wall 50 are designed to form a snug fit between sidewalls 20 and 30 and are held in place by latch mechanisms 32 and 34 , respectively. Bottom plate 60 interfaces with the sidewalls 20 and 30 and first end wall 40 and second end wall 50 to complete container 10 . Partitions 70 are arranged between the sidewalls 20 and 30 to section off individual compartments within container 10 . A hole or aperture 80 is placed in side walls 20 and 30 between partition channels 26 or between a partition channel 26 and a first end wall 50 or second end wall 60 . Also shown is bottom support 62 that supports bottom plate 60 during disassembly so as to prevent bottom plate 60 and the molded material within container 10 from falling and wedging the sticks if used.
Turning now to FIG. 2, there is illustrated container 10 in exploded view to show the individual components. First sidewall 20 and second sidewall 30 have a bottom ledge 22 . Bottom ledge 22 is designed to support bottom plate 60 when container 10 is assembled. Bottom ledge 22 must be strong enough to hold bottom plate 60 in place as well as any baking or molding material placed, inside of container 10 . Sidewalls 20 and 30 also have inside surface 24 found along the inner wall of the container 10 . Inside surface 24 may be flat or have a scalloped surface as illustrated. Inside surface 24 may also have a variety of different molding shapes, depending on the effect one wishes to create. FIG. 2A shows a lid or cover 85 sized to fit over pan 10 . Cover 85 is supported by sidewalls 20 , 30 and end walls 40 , 50 . A handle 86 may optionally be affixed to sidewalls 20 and/or 30 to facilitate handling of pan 10 . FIG. 2B is a cross-section along line B-B′ in FIG. 2 A. Plug element 92 is used to fill aperture 80 when a holding member is not used. Plug element 92 may have any structure provided that it plugs or fills aperture 80 to prevent any material placed within pan 10 does not leak out of an aperture 80 that does not have a holding member therein.
Grooves or notches 26 are located between sections of inside surface 24 . Grooves 26 are preferably placed along inside surface 24 at evenly spaced intervals. However, the spaced intervals may be uneven depending on a given mold design. Apertures 80 are located between grooves 26 or between a groove 26 and first end wall 40 or second end wall 50 . Partitions 70 are placed between the sidewalls 20 and 30 , and fit into opposed grooves 26 . Grooves 26 are offset on opposing sidewalls 20 and 30 so that any two adjacent partitions 70 would generally form a “V” shape.
The bottom plate 60 is shaped to match inside surface 24 of sidewalls 20 and 30 . In this way, bottom plate 60 forms a good fit with sidewalls 20 and 30 to retain the material placed into container 10 . The illustration also shows a detachable bottom support 62 . Bottom support 62 is designed to fit underneath bottom plate 60 in the space between bottom ledges 22 of sidewalls 20 and 30 . However, bottom support 62 is not needed until the finished product is complete and the material is to be removed from pan 10 .
When the pan 10 is disassembled, locking mechanism 32 and 34 are unlatched so that first end wall 40 and second end wall 50 may be removed. Sidewalls 20 and 30 are then pulled out away from the bottom plate 60 . Bottom support 62 prevents bottom plate 60 from dropping during the disassembly process, which prevents the stick, if used, from wedging and causing the molded material from breaking up. Bottom support 62 is connected to the bottom plate 60 by way of an alignment pin 64 spaced from each end of bottom support 62 . Alignment pin 64 fits into a corresponding hole 66 located on each end of the bottom plate 60 . It should be understood that the use of alignment pin 64 is not necessary, nor is hole 66 required in bottom plate 60 . The use of these features simply makes using pan 10 a little easier. Bottom support 62 and bottom plate 60 may also be made or combined to form one bottom plate 60 . For example, bottom plate 60 may be constructed as a one-piece unit or two-pieces integrally formed. Bottom plate 60 may be machined, molded or cast.
First end wall 40 and second end wall 50 are hingedly attached to first sidewall 20 in this illustration of the present invention at hinged connections 42 and 52 . Hinged connections 42 and 52 make it relatively easy for a user to assemble container 10 . Using an embodiment that does not have first end wall 40 and second end wall 50 privotally attached to first side wall 20 or second side wall 30 requires a user to fit the parts together in a skillful manner (like a puzzle). Opposite ends 44 and 54 of first end wall 40 and second end wall 50 are connected to the second side wall 30 using latched connections 32 and 34 . Latched connections 32 and 34 hold the side walls 20 and 30 , first end wall 40 , second end wall 50 , and bottom plate 60 together to make container 10 .
Referring to FIG. 3, a cross-section of container 10 is illustrated showing sidewall 30 and bottom plate 60 . Aperture 80 extends through sidewall 30 and is positioned between two grooves 26 (not shown). Aperture 80 is sized to accommodate a holding member 90 in a horizontal position in container 10 while the material solidifies. The holding member 90 may be a stick, a bar, a tube, or any device used to insert into the material and to hold the material onto holding member 90 . Wooden tongue depressors or craft sticks are examples of useable devices for holding member 90 .
Referring to FIG. 4, there is illustrated a cross-sectional view of another embodiment of bottom plate 60 . This embodiment shows bottom plate 60 as having a lower section 62 . Bottom plate 60 with lower section 62 may be a unitary piece that is molded or cast as one piece or an integral piece where lower section 62 is attached to bottom plate 60 . This embodiment of bottom plate 60 also prevents bottom plate 60 from falling during disassembly and helps prevent the molded material from breaking up.
Referring now to FIG. 5, there is shown a cross-sectional view of another embodiment of lower section 62 . This embodiment shows lower section 62 not only supporting bottom plate 60 but also supporting first sidewall 20 and second sidewall 30 . This design gives container 10 more stability.
Referring now to FIG. 6, there is shown another embodiment of first sidewall 20 and second sidewall 30 of the present invention. First sidewall 20 is shown having two sections, top section 20 a and bottom section 20 b. Top section 20 a has an array of spaced protrusions 21 a and bottom section 20 b has an array of spaced recesses 21 b that fit together like a puzzle to form sidewall 20 . When top section 20 a and bottom section 20 b are fitted together, protrusions 21 a and recesses 21 b form aperture 80 . This embodiment of sidewall 20 allows a molded material having a handle to be more easily removed from container 10 . Top section 20 a and bottom section 20 b may be held together by any convention means, particularly by means that allows for easy assembly and disassembly. It should be understood that top section 20 a and bottom section 20 b may both have matching recesses sized to form aperture 80 , or top section 20 a may be flat with bottom section 20 b having recesses sized to form aperture 80 when top section 20 a is joined to bottom section 20 b.
FIG. 7 shows another embodiment of first sidewall 20 . In this embodiment, top section 20 a is a top plate with an array of spaced protrusions 21 a. Bottom section 20 b has an array of spaced recesses 21 b. The difference is that bottom section 20 b is the full depth of container 10 and that top section 20 a does not have a matching inside surface 24 like bottom section 20 b. As in the previous embodiment, protrusions 21 a and recesses 21 b form a plurality of apertures 80 when top section 20 a is fitted to bottom section 20 b.
Referring now to FIG. 8, there is shown several different embodiments of partition 70 that can be used with the present invention. Partition 70 a is shown as being a straight piece that can be inserted into two opposing grooves 26 of container 10 . Partition 70 b is shown having a scalloped design that may give the molded material the shape of a tree. Partition 70 c is shown having a connected “V” shape. Any number of shapes and designs may be made and used to give the molded material the desired look. As previously stated, partition 70 a, 70 b and 70 c may be double-walled in order to provide more consistent heating or cooling to the individual portions in container 10 . Further, partition 70 may be created as a single piece forming multiple partitions where a plurality of apexes slide into a plurality of corresponding grooves 26 when placed into pan 10 . The component parts of pan 10 may also be coated with anti-stick material to prevent the finished product from adhering to pan 10 .
Although a specific form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. | An apparatus and method for shaping and molding material having two sidewalls, two end walls, a bottom and at least one partition. The two sidewalls have grooves spaced at predetermined intervals on an inside surface for receiving a partition and a bottom ledge for retaining the bottom. The inside surface has a plurality of openings sized for receiving holding members and may have a variety of shapes. The bottom is shaped to mate with the shape of the inside surface of the sidewalls. The two end walls include locking mechanisms for holding the various components of the apparatus together. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending application Ser. No. 529,113, filed Dec. 3, 1974, now abandoned, and entitled "METHOD AND APPARATUS FOR HOMOGENIZING STOCK IN THE HEADBOX OF A PAPER-MANUFACTURING MACHINE".
BACKGROUND OF THE INVENTION
The present invention relates to structure for keeping clean the interior surfaces in the headbox of a paper machine as well as for contributing to the homogeneity of the stock which flows through the headbox.
It is known that there is a tendency for matter such as fibers, fillers, or slime to adhere to and accumulate or build-up at interior surfaces of a headbox of a paper-manufacturing machine. These slime deposits may be of biological or non-biological origin.
The tendency of such contamination to occur in the interior of a headbox of a paper-manufacturing machine depends to a great extent on the design of the headbox, which is to say on the way in which flow velocities of the stock are arranged in different parts of the headbox. It can generally be assumed that locations which are particularly susceptible to contamination by build-up of matter as referred to above are those where the flow of stock is relatively slow as compared to the velocity of flow at other locations in the interior of the headbox. At such locations where there is a relatively low flow velocity for the stock dirt of other matter will begin to accumulate, even during perfectly normal types of operation, if the particular type of stock and other conditions are favorable for such contamination to take place.
In order to attempt to solve this problem it is known to utilize in a headbox flow channels shaped in order to achieve as much as possible a flow of stock which approaches as closely as possible to the ideal, and for this purpose such flow channels have ground or polished surfaces in order to achieve as great a smoothness as possible. Moreover, in paper mills it is known to utilize suitable additives in the pulp stock such as, so-called anti-slime agents.
However, even though attempts of the above type have been made to reduce the tendency of contaminating deposits to buildup at certain locations in the interior of the headbox, the desired results have not always been achieved. In fact it is necessary from time to time to completely shut down the paper machine only for the purpose of cleaning the headbox.
SUMMARY OF THE INVENTION
It is accordingly a primary object of the present invention to provide a structure which will avoid the above drawbacks.
In particular, it is an object of the present invention to provide a structure for effectively opposing the tendency of matter such as fibers, fillers, slime, or the like, to accumulate undesirably in the interior of the headbox.
Yet another object of the present invention is to provide a structure which will not only keep the interior of a headbox far cleaner than has heretofore been possible but which will in addition contribute to the homogeneity of the stock which flows through the headbox.
In accordance with the invention, at any location in the headbox where there is a tendency for matter such as fibers, fillers, slime, dirt, or the like, to accumulate, steam is introduced into the stock flowing in the headbox, this steam being introduced for example by way of suitable hollow bodies situated at locations of the above type where accumulations of the above type tend to occur. The hollow bodies have walls, such as sintered walls, formed with passages, such as those defined between the sintered particles, through which steam can flow from the interior to the exterior of the hollow bodies, and the interior of the hollow bodies communicate with a suitable supply of steam.
Steam which is introduced in this way into the stock flowing in the headbox has, of course, a temperature substantially higher than the temperature of the stock so that as a result the steam will condense in the stock. The steam forms bubbles in the stock and the stock which is relatively cold as compared to the steam causes a rapid condensation of the steam bubbles with the result that implosion takes place, accompanied by a pressure shock. These pressure shocks efficiently push the stock particles about, at the location where the steam is introduced, so as to prevent the stock particles from accumulating or becoming lodged at the locations where the steam is introduced, and in this way contamination in the interior of the headbox is prevented while at the same time a more homogeneous stock is achieved.
BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:
FIG. 1 is a schematic fragmentary sectional elevation of a headbox provided with the structure of the invention for carrying out the method of the invention;
FIG. 2 is a fragmentary sectional elevation taken along line II--II of FIG. 1 in the direction of the arrows; and
FIG. 3 is a sectional elevation fragmentarily illustrating part of the structure of FIG. 1, taken along line III--III of FIG. 1 in the direction of the arrows, and showing the structure at a scale which is enlarged as compared to FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is of particular utility in connection with the latest types of headbox where the older rotating flow equalizers, such as perforated rolls, have been replaced by static members such as various pipe bundles, or groups of rigid or flexible lamellae which are situated adjacent each other to define between themselves spaces through which the stock flows. The latter type of headbox has a tendency to accumulate dirt and other matter on the impact surfaces or leading edges of the lamellae at the input side of the static flow equalizers, the stock flowing toward these leading edge regions of the lamellae. As a result of this tendency for accumulations to form at these particular locations, it has been necessary from time to time to wash the accumulations off. In the event that they are not washed off soon enough, these deposits grow to a relatively large size and simply collapse into the flowing stock causing a pronounced lack of homogeneity in the stock. As a result, defects if not actual rupture of the paper web take place, in the event that accumulations of this type become detached from the edge regions of the lamellae or from other edge regions in the interior of the headbox where accumulations of the above type form.
According to the invention the leading edge regions of the static flow equalizers, formed by lamellae, can advantageously be made of a sintered material and steam can be conducted through the sintered material so that the implosion of the resulting steam bubbles in the stock as set forth above will be produced to keep these locations in the interior of the headbox clean in the manner described above.
Referring to the drawings, the headbox which is schematically illustrated in FIG. 1 includes an inlet region 9 to which stock is continuously supplied in a well known manner. This inlet region 9 extends across the entire width of the headbox, the width of the headbox extending perpendicularly with respect to the plane of FIG. 1. The stock which is thus introduced at the inlet 9 flows upwardly from the latter and then longitudinally through the interior of the headbox toward the left, as viewed in FIG. 1, so as to discharge from the aperture 8 of the headbox. A plurality of water-supply connections 10 are provided for the headbox at the right wall thereof, as viewed in FIG. 1.
The illustrated headbox is provided in its interior with flow equalizers in the form of oblique lamellae 1 which define between themselves relatively narrow spaces or flow ducts 2. The width of these flow ducts 2 is determined by the dimensions of the spacers 3 situated between the lamellae 1. Thus, FIG. 2 shows how the lamellae extend obliquely from the upper to the lower spacers 3. These spacers are in the form of groups of upper and lower relatively long bars which alternate with the upper and lower edge regions of the lamellae 1. Relatively long tie bolts 7 serve to compress the upper and lower edge regions of the lamellae 1 between the several elongated spacers 3 as well to connect the side walls 6 of the headbox to the groups of upper and lower spacers 3 as well as the groups of upper and lower edge regions of the lamellae 1 situated between the spacers 3 in the manner shown most clearly in FIG. 2. As a result it will be seen that the headbox has an upper wall 5 formed by the upper group of spacers 3 and lamellae clamped therebetween as well as a lower wall 4 formed by the lower group of spacers 3 and the lower edge regions of the lamellae clamped therebetween.
As may be seen from FIG. 1, the stock which enters through the transversely extending inlet 9 tends to flow upwardly toward the leading edge regions 1a of the lamellae 1. As is apparent from FIG. 1 each lamella 1 has an elongated leading edge 1a extending across the entire inlet 9 with the several leading edge regions 1a being distributed throughout the width of the headbox. Thus, the stock will enter into the relatively narrow spaces or flow paths 2 defined between the lamellae, as indicated in FIG. 2 where the several water-supply connections 10 are also illustrated respectively communicating with the spaces 2. The stock will now flow through the elongated spaces 2 defined between the lamellae toward the trailing edge regions 1b of the lamellae, these edge regions 1b being apparent in FIG. 1 and being considered trailing in the sense that the stock flows past and beyond these trailing edge regions 1b of the several lamellae 1.
With a headbox of the above construction there is a pronounced tendency for deposits to accumulate along the leading edge regions 1a of the lamellae 1. Such accumulation tends to take place along the entire length of each leading edge region 1a which extends across the entrance 9 of the headbox, in the manner illustrated in FIG. 1. In order to prevent such accumulation from occurring as well as to achieve other advantages of the invention, each leading edge region 1a has fixed thereto, along its entire length, an elongated hollow body 11 in the form of a tube having in cross section the configuration illustrated in FIG. 3. Thus, the several hollow bodies or elongated nozzle tubes 11 are welded to the leading edge regions 1a in the manner illustrated in FIG. 3. Each elongated hollow body 11 has a hollow interior space 12 forming an internal steam flow passage for each body 11. Moreover, the wall of each body 11, this wall surrounding the internal space 12, is formed with small holes or passages through which steam can discharge through the wall of each body 11 from the interior 12 thereof to the exterior into the stock flowing through the headbox. These passages are achieved by constructing each elongated hollow body 11 by way of sintered particles, or a different type of porous material may be used for each body 11. Thus, as a result of this construction the wall of the body is formed, between the sintered particles, for example, with passages through which steam can escape from the interior to the exterior of the body 11.
In the example illustrated in FIG. 1, at their left end regions, each elongated hollow body 11 has its interior in communication with a small tube which in turn communicates with an elongated header 13a extending across the entire headbox, and this header 13a communicates through a pipe 13 with a steam-supply means in the form of a steam-generating unit 14 schematically illustrated in FIG. 1. Of course the pipe 13 extends in a fluid-tight manner through the wall of the headbox which forms the inlet 9 thereof. Thus, by way of the steam-supply means 13, 14 it is possible to supply steam directly to the interiors 12 of the hollow bodies 11 with this steam then escaping from the interiors of the hollow bodies 11 through the passages formed in the walls of the hollow bodies into the stock forming in the latter steam bubbles which rapidly condense and create the implosion and resulting pressure shocks which achieve the results of the invention.
Of course, in addition to keeping the interior of the headbox clean by preventing deposits from accumulating as described above, the structure of the invention will also contribute to the homogeneity of the stock as a result of the prevention of detachment of clumps of deposits from locations such as edge regions of lamellae.
It is also possible to arrange the structure of the invention along the trailing edge regions 1b of the lamellae 1. Thus, hollow bodies 11 communicating at their interiors also with a steam supply means may be fixed to the edge regions 1b extending longitudinally therealong in the same way as these bodies 11 are fixed to the leading edge regions 1a, or a different but equivalent nozzle tube structure may be provided at the trailing edge regions 1b so as to prevent accumulation of contaminating deposits at the edge regions 1b as well as for contributing to the homogeneity of the stock which flows past the trailing edge regions 1b. It is also possible to situate the structure of the invention at other locations in the headbox where there is a tendency for deposits to accumulate, so that steam may be introduced at these additional locations to achieve the results of the invention as set forth above.
Thus, it will be seen that according to the present invention the desired results are achieved by the phenomenon according to which the stock flow, which is cold as compared to the steam delivered to the stock, causes condensation of the steam bubbles discharging from the nozzles or tubes at the small openings thereof. Therefore, the well known implosion phenomenon will result with the accompanying pressure shock, and these implosions and pressure shocks are utilized in accordance with the invention to keep the interior surfaces of the headbox clean as well as to contribute to the homogeneity of the stock. | A structure for keeping clean the interior of the headbox of a paper machine as well as contributing to the homogeneity of the stock flowing through the headbox. At a location in the headbox where there is a tendency for accumulation or build-up of matter such as fibers, fillers, slime, or the like, steam is introduced such as by supplying steam to the interior of a hollow body having a wall provided with passages through which the steam can escape to the exterior of the hollow body into the stock in the headbox. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to a twin wire former for application to the wire part of a paper machine.
An example of a conventional twin wire former is shown in FIG. 2: dewaterers 5, 7 are inside the loop of a wire 4, and a dewatering zone is configured so that the wire-run constituting the forming zone thereof is substantially vertical. A couch roll 8a is a suction roll, and the wet paper is transferred to the wire 4 on the couch roll 8a. In FIG. 1, reference numeral 1 denotes a head box, 2 is a raw material jet, 3 is a wire, 10 is a breast roll and 11 is a forming roll.
In another example of a conventional twin wire former shown in FIG. 3, dewaterers 6 and 7 are disposed alternately inside wire loops 3 and 4b; the first dewaterer is a roll 10a with a small radius of curvature, and as in FIG. 2 the couch roll 8b is a suction roll and the wet paper is transferred to the wire 4 as it passes over the couch roll 8b.
FIG. 4 shows a further example of a conventional twin wire former. The twin wire former in this case consists of diagonal twin wire loops; dewaterers 5c, 6c, 7c are disposed alternately inside the loops of two wires 3c, 4c, and the wet paper is transferred to the wire 4c on a curved transfer box. The dewaterer 5c has a small radius of curvature, and the couch roll 8c is a suction roll. The lower wire 4c passes around a breast roll 10c, the dewaterer 5c, a separating suction unit 9c, the dewaterer 7c and the couch roll 8c. The upper wire 3c passes around a forming roll 11c, the dewaterer 6c, and a tension roll 13c.
In the twin wire former shown in FIG. 2, because the dewaterers 5, 7 are both disposed inside the loop of the same wire 4, the effect of the dewaterers 5, 7 on the formation of the paper layer is asymmetrical. Also, because the couch roll 8a is a suction roll, the initial cost is high and because a large vacuum airflow is required the energy costs are also high. Furthermore, there are problems such as that because the top wire return roll 14a is swung up to replace the wires 3 and 4, the height required for the machine is large.
In the twin wire former shown in FIG. 3, because the initial dewatering is performed by the roll 10a having a small radius of curvature, this dewatering is sudden. Also, as in the case shown in FIG. 2, because the top wire return roll 14a is swung up for replacement of the wires, the height of the machine is large. Furthermore, because there are two suction couch rolls, there are the same problems of the initial cost and the energy costs being high as in the case shown in FIG. 2.
In the twin wire former shown in FIG. 4, the initial dewatering is sudden dewatering with a roll, as in FIG. 3, and as in the cases shown in FIG. 2 and FIG. 3 there are problems associated with the use of the suction couch roll 8.
SUMMARY OF THE INVENTION
An object of this invention is to provide a twin wire former which solves the problems described above by providing at least three dewaterers having large radii of curvature.
To achieve this and other objects, this invention is a twin wire former comprising two wire loops wherein between where the raw material jet alights on the wires and the couch roll at least three stationary dewaterers having large radii of curvature are disposed inside loops of one wire and the other wire equentially alternately, and the wire-run between where the raw material jet alights on the wires and the wire-run extending the above-mentioned section is diagonal.
Also, of the stationary dewaterers a first dewaterer is mounted inside the loops of one wire and a second dewaterer is supported pivotally about a point in the vicinity of its rear end inside the loop of the other wire, further, the couch roll is a solid roll, a curved transfer suction box is disposed behind the couch roll, the other wire moves away from the wet paper over the transfer suction box, and the couch roll and the transfer suction box and the dewaterer in front of the couch roll are mounted on a swing arm and are pivotable for wire replacement.
In this invention, because the radii of curvature of the dewaterers are large and the dewaterers are disposed alternately and diagonally, the dewatering zone can be made long within limited height restrictions, and gentle and front/back symmetrical dewatering can be achieved. Also, by the transfer suction box being provided behind the couch roll, the wet paper can be reliably transferred to one of the wires.
Furthermore, by the second dewaterer being supported pivotally about a point in the vicinity of its rear end and by the couch roll and the dewaterer in front of it and the transfer suction box behind it being swung down, the space between the various devices and slack in the wire loops necessary for wire replacement can be made.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a paper machine twin wire former according to a preferred embodiment of the invention;
FIG. 2 is a front view of a conventional paper machine twin wire former;
FIG. 3 is a sectional view of a forming and dewatering zone of another conventional example;
FIG. 4 is a front view of a further example of a conventional paper machine twin wire former;
FIG. 5 is a sectional front view showing a conventional dewaterer;
FIG. 6 is a perspective view of a first blade in FIG. 5;
FIG. 7 is a perspective view of a first blade in FIG. 5 different from that of FIG. 6;
FIG. 8 is a view showing in cross-section another conventional dewaterer and a pressure waveform associated therewith; and
FIG. 9 is a view showing in cross-section a conventional dewaterer different from that of FIG. 8 and a pressure waveform associated therewith.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention will now be described, with reference to the accompanying drawings. FIG. 1 shows a preferred embodiment of the invention. In FIG. 1, reference numeral 1 denotes a head box; 2 is a raw material jet; 3 and 4 are wires; and 5, 6 and 7 are first, second and third dewaterers having large radii of curvature, respectively. The first dewaterer 5 is mounted inside the loop of the wire 4, the second dewaterer 6 is mounted inside the loop of the other wire 3, and the third dewaterer 7 is mounted in front of a couch roll 8 inside the loop of the wire 4. The second dewaterer 6 is supported pivotally about a point in the vicinity of its rear end 6a, and the first, second and third dewaterers 5, 6, 7 are disposed alternately. The couch roll 8 is a solid roll, and a curved transfer suction box 9 is disposed behind this couch roll 8. Reference numeral 10 denotes a breast roll; 11 is a forming roll; 12-1, 12-2 are worm jacks; 13 is a swing arm which supports the couch roll 8, the transfer suction box 9 and the third dewaterer 7 and has its front end pivotally supported so that it can pivot these components for wire replacement; and 14 is a leadout roll. The worm jack 12-1 is connected to the second dewaterer 6, and the worm jack 12-2 is connected to the swing arm 13.
The raw material jet 2 sprayed out of the head box 1 is sandwiched between the two wires 3 and 4 in front of the first blade of the first dewaterer 5 disposed inside the wire loop 4 and undergoes initial dewatering by a dewatering pressure resulting from the radius of curvature of the blade and tension in the wires. At this time, because the radius of curvature of the first dewaterer 5 is large compared to a roll, the dewatering pressure is low and the dewatering is gentle. The dewaterers shown in FIG. 5 to FIG. 7 can be used as the first dewaterer 5.
The first dewaterer 5 is a conventional one. Describing this with reference to FIG. 5 to FIG. 7, a first blade 15 of the first dewaterer 5 is disposed where the wires 3 and 4 converge; this first blade 15 has a wide surface having a large radius of curvature R 1 which curves convexly on the wire 3, 4 side and supports the wire 4, and is removably mounted on a T-bar 5a fixed to the first dewaterer 5. The above-mentioned surface of the first blade 15 has multiple grooves provided spaced in the width direction, orthogonal to the direction of travel of the wires, of the kind shown in FIG. 6 or FIG. 7. Grooves 15a in FIG. 6 start from a point a distance L from the upstream edge of the blade and with a depth h extend in the travel direction of the wires toward the downstream side and are open at the downstream side of the blade. A land portion 15c continuous in the width direction is formed along the leading side of the blade, and this portion of the blade can scrape off water clinging to the wire 4 uniformly in the width direction.
Consequently, when the raw material jet 2 is sandwiched between the wires 3, 4 it is dewatered on both sides through the wires 3, 4 by a dewatering pressure created by tension in the wire 3 and the radius of curvature R 1 of the surface of the first blade 15, as mentioned above. White water passing through the wire 4 to the blade side at this time passes along the grooves 15a and is discharged through the open ends thereof. The width w and the pitch s of the grooves are fixed at suitable dimensions such that incursion of the wires and width direction dewatering nonuniformity do not occur.
FIG. 7 shows another groove shape of a first blade 15'. In FIG. 7, the grooves 15a' start at a point a distance L from the leading edge of the blade and extend downstream in the travel direction of the wire, and also slope at an angle B toward the downstream side of the blade. As a result of the grooves 15a' having this kind of shape, a vacuum created by a foil effect acts in addition to the dewatering pressure, and dewatering is promoted more than in the case of the grooves 15a shown in FIG. 6. Reference numeral 15c' denotes a land portion.
The raw material liquid sandwiched between the wires 3 and 4 enters a dewatering zone disposed continuous with the first blade 15 on the downstream side thereof. In FIG. 5, this dewatering zone consists of a perforated plate 16 comprising multiple slots 16a alternating with multiple land portions 16b, both continuous in the width direction. This dewatering zone is divided into three zones disposed in order from upstream to downstream: a first zone (I), a second zone (II) and a third zone (III). The land upper surface of the first zone (I) which supports the wire 4 curves convexly on the wire 4 side with a radius of curvature R 2 , the land upper surface of the second zone (II) which supports the wire 4 is flat, and the land upper surface of the third zone (III) which supports the wire 4 curves convexly on the wire 4 side in the same direction as the first zone (I) with a radius of curvature R 3 . The second zone (II) between the first zone (I) and the third zone (III) is partitioned by a partition 5b, and the first zone (I) together with the second zone (II) and separately from these the third zone (III) are respectively connected to different vacuum sources. The above-mentioned first through third zones (I), (II) and (III) may consist of the same perforated plate or may alternatively for convenience of manufacture each be constituted by a separate perforated plate.
Next the raw material liquid moves to the second dewaterer 6 disposed inside the loop of the wire 3 and is dewatered by the action of a dewatering element installed there. The dewaterers shown in FIG. 8 and FIG. 9 can be used as this second dewaterer 6.
This second dewaterer 6 is a conventional dewaterer, and in a first example thereof shown in FIG. 8, because the wires 3 and 4 sandwiching the raw material liquid move past the front edge 17a of a shoe blade 17 without being bent by that leading edge, a large pressure is not developed, the pressure which does develop is just a small pressure P 1 resulting from the impact reaction of the white water, and the shear force exerted on the mat between the wires is also small. Consequently the dewatering effected by causing a vacuum to act between the shoe blades 17 is dewatering which is away from the fiber dispersion location and is close to static dewatering, and is of high yield.
The wires 3, 4 sandwiching raw material liquid having passed the shoe blade front edge 17a bend through an angle B 1 at the front end of the rear edge 17c. At this time a pulse pressure develops and redispersion of the fiber is promoted. The peak value of this pulse pressure can obviously be changed by changing the shape parameters (A, α) which determine the size and shape of the wedge-shaped space formed between the wire 3 and a land portion 17b obtained by making the portion of the shoe blade 17 between the front edge 17a and the rear edge 17c sloped. (The dewaterer 6 of FIG. 8 is shown with its array direction on the opposite side with respect to the wires 3, 4 to FIG. 1.)
FIG. 9 shows an example of another conventional dewaterer 6 different from that of FIG. 8, wherein the construction and functions of the front edge 17a', the land portion 17b' and the rear end 17c' are the same as in FIG. 8. In addition to this the shoe blade 17 has a land portion 17d' which slopes downstream in the same way as a Fourdrinier foil blade, and because dewatering can be effected by the vacuum force generated in the space formed by this land and the wire 3, it is possible to economize on vacuum sources. As in the Fourdrinier case, it is possible to adjust the dewatering force by changing the angle β.
Because by disposing the first and second dewaterers 5 and 6, having the actions described above, inside the wire loops 3 and 4 alternately the action of the shoe blades acts from both sides of the wet paper, a mat whose front and back sides are of the same quality is formed. The mat formed in this way passes over the third dewaterer 7 and has its density further increased before arriving at the couch roll 8.
Also, because the dewatering zone formed by the first to third dewaterers 5, 6, 7 is long and has a sufficient dewatering capability, a plain solid roll can be used instead of the suction roll for the couch roll 8, and problems such as breaking up of the wet paper at high speed do not occur.
Further, although the dewatering zone is long, because the dewatering zone is disposed at an incline, the position of the couch roll is approximately the same as it is conventionally and the height of the machine is not increased. By the couch roll 8 being made a solid roll and the curved transfer suction box 9 being disposed behind the couch roll and the wire 3 being removed from the wet paper as it passes over the transfer suction box 9, the wet paper remains on the wire 4 and is transported to the presspart of the next step.
When the wires 3, 4 are to be replaced, by pivoting the second dewaterer 6 inside the wire loop 3 about a point in the vicinity of the rear end 6a thereof by means of the worm jack 12-1 and swinging down the third dewaterer 7, the couch roll 8 and the transfer suction box 9 mounted on the swing arm 13 disposed inside the loop of the wire 4 by means of the worm jack 12-2, space between the devices is made and at the same time a large margin for installing the wires is obtained.
As described above, with the present invention, because the radii of curvature of the dewaterers are large and the dewaterers are disposed sequentially alternately inside the loops of one wire and the other wire and the dewatering zone is long, gentle and front/back-symmetrical, dewatering can be achieved and paper with good yield and excellent front/back similarity can be obtained.
Furthermore, because the couch roll is a solid roll and a curved transfer suction box is disposed behind the couch roll, the initial cost and running costs are lower compared to a conventional case wherein a suction roll is used, and because there is provided a swing arm and the couch roll and the transfer suction box and the dewaterer in front of the couch roll are mounted thereon, and this swing arm is swung down by means of a worm jack, space between the devices can be made and a large margin for installing the wires can be obtained. As a result, with this invention, by means of the sloping dewatering zone arrangement and the swing down structure for wire replacement, the height required for installation of the machine can be reduced. | A twin wire former of a paper machine can perform dewatering gently and symmetrically on the front and back sides of the wet paper, thereby producing paper with good yield and excellent front/back similarity. The twin wire former includes the loops of two wires, and first, second and third dewaterers, having large radii of curvature and disposed inside one and the other of the loops of the wires sequentially alternately between a point where a raw material jet alights on the wires and a couch roll, and the wire-run over this section is diagonal. The first and third dewaterers are disposed inside the loop of the wire and the second dewaterer is disposed inside the loop of the wire. This second dewaterer is pivotable about a point in the vicinity of its rear end, and the couch roll is a solid roll. This couch roll, a transfer suction box and the third dewaterer are mounted on a swing arm and can be pivoted for wire installation. | 3 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a power source in which an alkali metal is oxidized to provide heat. More specifically, it relates to lithium pellets that are coated with a fluorinated oil in a lithium reaction vessel.
[0002] In certain situations, it is necessary to provide propulsion in an environment where oxygen is not available. Underwater vehicles, such as torpedoes, are one such situation. Torpedo propulsion systems frequently use a vaporized fluid (such as water) to drive a turbine, and the turbine then drives a suitable propulsor. Typically, water is vaporized in a boiler that is heated by an intensely exothermic chemical reaction, such as metallic lithium oxidized with sulfur hexafluoride.
[0003] The lithium used in such a boiler may be either a solid piece of lithium or lithium pellets coated with a fluorinated polymer. However, both of these forms of lithium fuel have certain drawbacks.
[0004] For example, using a solid block of lithium involves using aluminum potassium perchlorate as a thermal starting device to heat the boiler and the lithium inside it to operating temperature. The aluminum potassium perchlorate generates high temperatures, typically in the range of about 3000 to 4700° C., and must be formed into pellets that are closely packed together in order to initiate the system. To achieve this, core holes are formed in the lithium, and the core holes are filled with the aluminum potassium perchlorate. A squib is also provided within the core hole, and the core is then sealed with a lithium plug. Substantial pressures are generated during ignition of the aluminum potassium perchlorate, requiring the boiler structure to be very strong. Moreover, if the aluminum potassium perchlorate, while undergoing oxidation, contacts the boiler surfaces, it can burn through parts of the boiler and damage the system.
[0005] To avoid these problems associated with using a solid lithium core, encapsulated lithium pellets are more commonly used. The lithium pellets are generally spherical in shape and have diameters in the 1-25 millimeter range. The pellets are of varying sizes to allow for close packing of the pellets. In addition, each pellet is provided with a coating of a fluorine-substituted hydrocarbon material, typically a polymer or telomer. Commercially available materials suitable for such a coating include products sold under the trademarks Teflon® and Vydax®. The coated lithium pellets are placed inside a boiler and a starter squib is fired, which melts the pellets adjacent to the starter squib. The melted lithium pellets react with their coatings, generating sufficient heat to propagate the reaction throughout the boiler. Sulfur hexafluoride is supplied to the boiler in a controlled fashion to maintain the reaction at a desired rate.
[0006] However, coating the lithium pellets with a fluorinated hydrocarbon is a complex, multi-stage process. For example, a typical process begins with placing the lithium pellets in a sealed tumbler in which they can be agitated. The interior of the tumbler is filled with an inert gas, such as argon. The coating material is dispersed in a liquid, and the resulting slurry is sprayed on the pellets inside the tumbler. The pellets are agitated during the spraying in order to provide an even coating. After the desired build-up of coating is achieved on the lithium pellets, the spraying is stopped and a slight vacuum is formed in the interior of the tumbler in order to evaporate the liquid applied to the lithium pellets within the tumbler. After the liquid has evaporated, the process is repeated several times until the desired thickness of coating is achieved.
[0007] Alternatively, lithium pellets can also be coated inside of the boiler. Lithium pellets are placed inside of the boiler, and a fluorinated hydrocarbon dissolved or suspended in a solvent is poured into the boiler. The solvent is evaporated under a vacuum using heat. The process is repeated, if necessary, until a sufficiently thick layer of fluorinated hydrocarbon coats the lithium pellets.
[0008] Coating lithium pellets with a sufficiently thick layer of fluorine-substituted polymer or telomer may require many layers to be applied, so the process can take several days to complete. Thus, there is an additional need for a simple, low-cost method of applying a coating to lithium pellets. In addition, the fluorine-substituted telomers commonly used to coat lithium pellets are no longer available, having been removed from the market because of environmental concerns. Thus, there is a need for a commercially available, off-the-shelf material that can be used to coat lithium pellets for use in a lithium reaction vessel. Both of these needs should be satisfied without significantly diminishing the advantages obtained by using coated lithium pellets in a lithium reaction vessel.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is a lithium fuel pellet that is coated with a fluorinated oil, rather than a fluorinated polymer or telomer, and a process for applying the coating to a lithium pellet. An appropriate fluorinated oil is simply poured into the boiler after it is loaded with a binary mixture of lithium pellets. The oil adheres to the lithium pellets and does not settle to the low point of the boiler cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view of a portion of a lithium boiler utilizing the invention.
[0011] FIG. 2 is a flow diagram illustrating the manner of coating lithium pellets with a fluorinated oil for use in a lithium boiler.
[0012] FIG. 3 is a block diagram of the propulsion system with a lithium boiler utilizing the invention.
DETAILED DESCRIPTION
[0013] FIG. 1 shows an embodiment of the invention. A mixture of lithium pellets including large lithium pellets 11 and small lithium pellets 12 is placed into boiler 20 of a lithium reaction vessel. Large lithium pellet 11 is roughly spherical in shape, with a diameter of about 1.25 centimeters (cm). Small lithium pellet 12 is roughly spherical or cylindrical in shape, with a diameter of about 1.5 millimeters (mm) and, for a cylindrical pellet, a length of about 1.5 mm. Because of their smaller size, small lithium pellets 12 react more readily than large lithium pellets 11 , so small lithium pellets 12 are used to initiate a reaction in boiler 20 . Large lithium pellets 12 , in turn, are used to maintain the reaction for the desired period of time. Those skilled in the art will recognize that the size and shape of lithium pellets used in the mixture of pellets is a design choice, and the invention is not limited to any particular size and shape of lithium pellets. Similarly, while lithium is used as an example because it is the metal most commonly used as fuel, other alkali metals, particularly sodium and potassium, may also be used.
[0014] After large lithium pellets 11 and small lithium pellets 12 have been placed in boiler 20 , fluorinated oil 30 is poured into boiler 20 . Fluorinated oil 30 is a liquid, and it fills the spaces between and around large lithium pellets 11 and small lithium pellets 12 . Commercially available fluorinated oils that can be used in connection with the invention include oil and grease products sold under the trademark Krytox® by E.I. du Pont de Nemours and Company, and particularly the Krytox® GPL 100-107 series. Krytox® is a perfluoropolyether (PFPE), also called perfluoroalkylether (PFAE) or perfluoropolyalkylether (PFPAE). Krytox® fluorinated oils are a series of low molecular weight, fluorine end-capped, homopolymers of hexafluoropropylene epoxide. The polymer chain is completely saturated and contains only the elements carbon, oxygen and fluorine; hydrogen is not present. On a weight basis, Krytox® contains 21.6% carbon, 9.4% oxygen and 69.0% fluorine.
[0015] After the fluorinated oil 30 is introduced into boiler 20 , boiler 20 is rotated or otherwise agitated in order to evenly coat large lithium pellets 11 and small lithium pellets 12 with fluorinated oil 30 . Fluorinated oil 30 adheres to the surface of large lithium pellets 11 and small lithium pellets 12 , forming a coating 32 on the lithium pellets. The period of agitation is relatively short, typically only a few hours.
[0016] Lithium boiler 20 is now fueled and ready for use. A reaction may be initiated in any conventional way, such as using a squib and a detonation cord (not shown) to ignite small lithium pellets 12 . The detonation cord will raise the temperature of small lithium pellets 12 above their melting point, and small lithium pellets 12 will react with coating 32 . This reaction is exothermic and releases sufficient heat to melt large lithium pellets 11 , causing them to react with coating 32 and fluorinated oil 30 . Thus, the reaction spreads throughout boiler 20 . An oxidizer, such as sulfur hexafluoride, is then injected into boiler 20 . The lithium reacts with the sulfur hexafluoride in an intensely exothermic manner, raising boiler 20 to its operating temperature of about 1100° C. Boiler 20 then heats a working fluid, such as water, above its boiling point, and the resulting steam is used to turn a turbine.
[0017] FIG. 2 is a flow diagram illustrating the manner of coating lithium pellets with fluorinated oil for use in a lithium reaction vessel. The process 100 begins at Start box 110 . Process 100 then moves to box 120 , where a binary mixture of lithium pellets is introduced into the lithium reaction vessel of the boiler. As discussed previously, the invention is not limited to any particular size of lithium pellets. Different sizes and shapes of lithium pellets are commonly mixed together when lithium pellets are used as fuel. Optimally, the mixture of lithium pellets used at box 120 is a binary mixture of pellets similar to large lithium pellets 11 and small lithium pellets 12 , which were discussed with respect to FIG. 1 .
[0018] Next, at box 130 , fluorinated oil sufficient to coat the lithium pellets is added to the binary mixture of lithium pellets in the boiler. As discussed with respect to FIG. 1 , commercially available fluorinated oils that can be used in connection with the invention include oil and grease products sold under the trademark Krytox® by E.I. du Pont de Nemours and Company, and particularly the Krytox® GPL 100-107 series.
[0019] At box 140 , the boiler is agitated to uniformly coat the mixture of lithium pellets with the fluorinated oil. Typically, this agitation involves rotating the boiler containing the lithium pellets and fluorinated oil. However, any sort of agitation sufficient to coat the lithium pellets with fluorinated oil could take place at this step.
[0020] The process ends at End box 150 .
[0021] The present invention can be used in any application in which lithium is used as fuel. The oxidation of lithium with sulfur hexafluoride does not require oxygen, so it can occur in places where oxygen is not available, such as underwater and outer space. Most commonly, lithium reaction vessels are used as a heat source for propulsion in underwater devices, particularly torpedoes, and this invention can certainly be used in that application. Lithium reaction vessels have also been considered for use as a heat source for emergency power supplies for space vehicles, and the present invention could also be used to fuel a lithium reaction vessel used in that manner.
[0022] FIG. 3 is a block diagram showing one application of the invention. Propulsion system 300 includes boiler 310 , turbine 320 and propulsor 330 . Boiler 310 corresponds to boiler 20 in FIG. 1 and is filled with a mixture of lithium pellets that are coated with a fluorinated oil, as described in detail with respect to FIG. 1 . Boiler 310 heats a working fluid, such as water, and the resulting steam is used to turn turbine 320 . Turbine 320 is connected to propulsor 330 , and propulsor 330 turns along with turbine 320 to generate propulsion.
[0023] The present invention is a lithium pellet coated with a fluorinated oil for use as fuel in a lithium reaction vessel and a process for coating the pellets. The invention can use readily-available commercial materials and takes a small fraction of the amount of time needed to coat lithium pellets according to the prior art.
[0024] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | Lithium fuel pellets are coated with a fluorinated oil, rather than a fluorinated polymer or telomer. The lithium pellets are coated by placing the pellets inside the lithium reaction vessel and then pouring a fluorinated oil into the reaction vessel. The reaction vessel is rotated in order to evenly coat the lithium pellets. The oil adheres to the lithium pellets and does not settle to the low point of the boiler cavity. | 5 |
This application is a continuation of Ser. No. 09/347,585 filed on Jul. 1, 1999 now U.S. Pat. No. 6,185,822, which is a continuation of Ser. No. 08/807,492 filed on Feb. 27, 1997 now U.S. Pat. No. 5,956,848.
This invention relates to shaving systems.
In shaving systems of the wet shave type, factors such as the frictional drag of the razor across the skin, the force needed to sever hairs, and irritation of preexisting skin damage can create a degree of shaving discomfort. Discomfort and other problems accompanying wet shaving systems can be alleviated by the application of shaving aids to the skin. Shaving aids may be applied prior to, during, or after shaving.
A number of problems accompany the use of pre- and post-applied shaving aids. Pre-applied shaving aids can evaporate or can be carried away from the site of application by repeated strokes of the razor. Post-applied shaving aids are not present on the skin during shaving and thus their application may be too late to prevent an unwanted effect. Moreover, the application of both pre-applied and post-applied shaving aids add additional steps to the shaving process.
It is known to incorporate a shaving aid into a razor by mounting a composite including the shaving aid to the razor. For example, Rogers et al., U.S. Pat. No. 5,113,585 describes a composite including a water-insoluble matrix material, a water-soluble shaving aid, and a low molecular weight release enhancing agent. When exposed to water during shaving, the water-soluble shaving aid leaches from the composition onto the skin. The release enhancing agent also dissolves in the water and improves the release of the water-soluble shaving aid from the composite.
SUMMARY OF THE INVENTION
The invention features a wet shaving system. The system includes a blade member including one or more blades and an external skin-engaging portion in proximity to the blade member. The shaving system may be, for example, a disposable shaving cartridge adapted for coupling to or uncoupling from a razor handle, or a shaving head which is integral with a razor handle so that the complete razor is discarded as a unit when the blade or blades become dulled. The blade edge cooperates with the skin engaging portion to define shaving geometry.
Significantly, the skin-engaging portion includes a polymeric shaving aid composite including two adjacent exposed lengthwise-extending portions, each containing a shaving aid. The shaving aid included in each portion may be the same or different. The composite can be, for example, an extruded composite.
A shaving aid composite having adjacent, lengthwise-extending portions provides a number of potential design advantages. For example, one portion may contain a larger quantity of water-insoluble resin than the second portion, while the second portion contains a larger quantity of shaving aid than the first portion. The first portion, then, may provide support to the second portion, which in turn may release a significant quantity of shaving aid during shaving without breaking down or causing the shaving geometry to change significantly.
Furthermore, the arrangement provides a way to incorporate incompatible shaving aids into the same shaving system. One shaving aid, for example, may chemically react with another, if they are mixed together. Likewise, a shaving aid, if included in too large a quantity in a composite that also includes another shaving aid, may unfavorably impact the wear characteristics of the composite or, for example, when the other shaving aid is a lubricous water-soluble polymer, to reduce the lubricity provided by the composite. Similarly, one shaving aid may require elevated processing temperatures during an extrusion procedure that would cause a second shaving aid to decompose. By including these shaving aids in different portions of the composite, the composite can be coextruded with different processing temperatures for each portion.
Moreover, the two portions can provide a desirable surface geometry for the composite. For example, the portions may be rounded, which may provide an enhanced skin-engaging surface on the composite. Alternatively, the exposed surface of one portion may be raised slightly relative to the second portion, which may enhance the wear characteristics of the first portion.
The invention also features a shaving system that includes two adjacent exposed lengthwise extending portions, one of which contains a colorant. The second portion has a different color than the first portion; it may, for example, contain no colorant or a colorant different from the colorant used in the first portion. The colorant in the first portion is released (e.g., by leaching or by wear) during shaving. When first used, the composite preferably has a striped appearance caused by the contrast between the two positions. One or both of the portions may also contain a shaving aid.
Other features and advantages of the invention will be apparent from the description of the preferred embodiment thereof, and from the claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a razor unit in accordance with the invention.
FIG. 2 is a perspective view of a shaving aid composite in accordance with the invention.
FIG. 3 is a side view of the composite in FIG. 2 .
FIG. 4 is a perspective view of a second shaving aid composite in accordance with the invention.
FIG. 5 is a perspective view of a third shaving aid composite in accordance with the invention.
DETAILED DESCRIPTION
The replaceable shaving cartridge 10 shown in FIG. 1 is of the type shown in U.S. Ser. No. 08/630,437, filed Apr. 10, 1996, which is assigned to the same assignee as the present application and is hereby incorporated by reference. It includes housing 16 , which carries three blades 18 , guard 20 , and striped solid, polymeric shaving aid composite 22 , which is in the form of an elongated insert member. The shaving aid composite is locked in an opening in the rear of the cartridge and includes a shaving aid that, during shaving is released by the composite to improve shave attributes. While shown at the rear portion of this particular shaving cartridge, the shaving aid composite may be located at any skin-engaging portion of the shaving unit and may be fabricated in any size or shape deemed appropriate. For example, the composite can be incorporated into the shaving units described in U.S. Pat. No. 4,586,225, which is incorporated by reference herein.
Referring to FIGS. 2 and 3, shaving aid composite 14 includes lengthwise-extending portions 44 , 46 , and 48 (each in the shape of a rounded lobe), each including a lengthwise-extending exposed surface. Composite 14 also includes connecting portion 49 , which connects portions 44 and 48 and also optionally serves to lock the composite into a mating receiving portion of the cartridge. Portions 44 and 48 and connecting portion 49 have the same compositions and, together, surround all but the exposed face of portion 46 . They can provide support for portion 46 . Portions 44 , 46 , and 48 each may be, for example, between 1.20 inches and 1.35 inches (more preferably between 1.25 inches and 1.275 inches) in length, and between 0.07 inch and 0.11 inch (more preferably between 0.085 inch and 0.095 inch) in width.
Portions 44 , 46 , and 48 each contains a water insoluble polymer, optionally in different amounts, and a shaving aid. They may contain the same shaving aid, or different shaving aids. In one embodiment portions 44 and 48 are identical, and contain the same shaving aid, while portion 46 contains a different shaving aid, optionally in combination with the same shaving aid contained in portions 44 and 48 .
Each portion also may contain other conventional shaving and composite ingredients, such as low molecular weight water-soluble release enhancing agents such as polyethylene glycol (e.g., 1-10% by weight), water-swellable release enhancing agents such as cross-linked polyacrylics (e.g., 2-7% by weight), colorants, antioxidants and preservatives. Water-soluble release enhancing agents are described in U.S. Pat. No. 5,113,585, which is hereby incorporated by reference. Water-swellable release enhancing agents are described in U.S. Ser. No. 08/121,153, filed Sep. 13, 1993, which is assigned to the same assignee as the parent application and is hereby incorporated by reference. Portions that contain a colorant can be designed to release the colorant, and change color, during shaving, preferably in response to wear of the portion. A portion may contain, for example, between about 0.1% and about 5.0% (preferably between about 0.5% and 3%) colorant by weight.
Suitable water-insoluble polymers which can be used include polyethylene, polypropylene, polystyrene, butadiene-styrene copolymer (e.g. medium and high impact polystyrene), polyacetal, acrylonitrile-butadiene-styrene copolymer, ethylene vinyl acetate copolymer and blends such as polypropylene/polystyrene blend.
Preferably, each portion includes about 5% to 50%, more preferably about 15 to 40%, and most preferably about 20 to 35% by weight of the water-insoluble polymer. The more preferred water-insoluble polymer is polystyrene, preferably a general purpose polystyrene such as BASF 2824 or a high impact polystyrene (i.e. polystyrene-butadiene), such as Mobil 4324. The portion should contain a sufficient quantity of water-insoluble polymer to provide adequate mechanical strength, both during production and use.
A shaving aid is a substance that enhances shaving performance. It may, for example, improve shaving comfort (e.g., by lubricating the skin, improve shaving efficiency, condition the beard, or condition the skin. Examples of shaving aids include lubricous water-soluble polymer such as polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate; beard hair softeners; oils such as silicone oil and mineral oil; substances that enhance the healing or stop the bleeding of the skin; essential oils such as menthol, eugenol, eucalyptol, safrol, and methyl salicylate; rinsing aids; non-volatile cooling agents; inclusion complexes of skin-soothing agents with cyclodextrin; fragrances; vitamin E (including common forms of vitamin E such as vitamin E acetate); vitamin A and B-carotene; panthenol and aloe; antipruritic/counterirritant materials; antimicrobial/keratolytic materials; anti-inflammatory agents; and astringents.
Enough shaving aid should be included to provide the desired benefit. A portion may contain, for example, about 20% to about 80%, more preferably about 40% to about 75%, by weight of a lubricous water soluble polymer. A portion also may include, for example, about 0.01% to about 5.0%, more preferably about 0.05 to about 1.0%, vitamin E (or common forms of vitamin E) by weight.
The preferred lubricous water-soluble polymer is polyethylene oxide. The more preferred polyethylene oxides generally are known as POLYOX (available from Union Carbide Corporation) or ALKOX (available from Meisei Chemical Works, Kyoto, Japan). These polyethylene oxides will preferably have molecular weights of about 100,000 to 6 million, most preferably about 300,000 to 5 million. The most preferred polyethylene oxide comprises a blend of about 40 to 80% of polyethylene oxide having an average molecular weight of about 5 million (e.g. POLYOX COAGULANT) and about 60 to 20% of polyethylene oxide having an average molecular weight of about 300,000 (e.g. POLYOX WSR-N-750). The polyethylene oxide blend may also advantageously contain up to about 10% by weight of a low molecular weight (i.e., MW<10,000) polyethylene glycol such as PEG-100.
The shaving aid composite may be fabricated by any appropriate method, including injection molding and extrusion, the latter being preferred.
A preferred shaving aid composite is provided below. Portions 44 and 48 (and connecting portion 49 ) are the same in each example. One shaving aid composite includes a central blue portion ( 46 ), the other a central green portion ( 46 ). The colorant in the central portion is released during shaving, generally by the gradual wearing away of that portion during use, thereby indicating through color change that the shaving aid originally contained in the central portion is no longer being delivered.
Because of the rounded lobe geometry of portions 44 , 46 , and 48 , including the significant recesses at the junctions of portions 44 and. 46 . and portions 46 and 48 , the shaving aid composite may have more surface area available to contact the skin than, for example, a shaving aid composite having a flat skin-engaging surface. This may provide increased lubrication for the skin and may reduce the time it takes for portion 46 to wear away. The raised elevation of the exposed surface of portion 46 relative to the exposed surface of portions 44 and 48 also may enhance the rate of wear of portion 46 .
In the chart, the components used in the shaving aid composites are provided in the first column on the left. The quantities of each component in portions 44 and 48 and connecting portion 49 are provided in the second column. The third and fourth columns provide ranges for the quantities of components that are used in the shaving aid composite including a central blue portion ( 46 ). The fifth and sixth columns provide ranges for the quantities of components that are used in the shaving aid composite including a central green portion ( 46 ).
Portion 46
Portion 46
Component
Portions 44,
(Blue)
(Green)
Description
48, and 49
HI
LO
HI
LO
BASF 2824 (CPS)
33.54%
22.50%
32.50%
23.00%
33.00%
Polyox Coag. 1
33.02%
32.86%
38.86%
32.86%
38.86%
Polyox WSR N750
21.99%
0.00%
21.99%
0.00%
21.99%
N-750 w/Vit E 2
0.00%
21.99%
0.00%
21.99%
Dow 4500 PEG
10.00%
10.00%
10.00%
10.00%
10.00%
Coz Stripwte. 3
1.20%
0.00%
0.00%
0.00%
0.00%
B215 Irganox 4
0.25%
0.25%
0.25%
0.25%
0.25%
t-green 5
0.00%
0.00%
3.50%
3.50%
Blue 1811-C 6
1.00%
1.00%
0.00%
0.00%
100.00%
1 High impact polystyrene (e.g., Mobil 4324) could also be used.
2 Vitamin E liquid (from Hoffman-LaRoche) spray coated on powdered N750 (4% load).
3 Polystyrene-based color concentrate containing TiO 2 (white) (from Coz Corp.).
4 Antioxidant (from Ciba Geigy).
5 Polystyrene-based color concentrate (T-Green) (from Coz Corp.).
6 Polystyrene-based color concentrate (GN-Blue) (from Coz Corp.).
A preferred shaving aid composite has the following composition:
Component
Weight %
Portions 44, 48, and 49
Mobil 4324
33.54%
Polyox Coag.
33.02%
Polyox WSR N750
21.99%
Dow 4500 PEG
10.00%
Coz Stripwte.
1.20%
B215 Irganox
0.25%
TOTAL
100.00%
Portion 46
BASF 2824 CPS
24.00%
Polyox Coag.
38.86%
Polyox WSR N750
3.90%
Dow 4500 PEG
10.00%
GN Blue
1.00%
B215 Irganox
0.25%
Polyox WSR N-750
21.99%
w/Vit E (4%)
TOTAL
100.00%
The shaving aid composites can be prepared by conventional coextrusion or molding methods known to those skilled in the art. For example, the components of the composite may be supplied by two separate melting/pumping (plastics extruders), each consisting of a heated barrel, a pumping screw, a motor drive for that screw and a control system for the entire system. The materials of the composite are fed in powder form into their respective extruders (e.g., single screw type manufactured by Davis Standard). The extruders can operate at the same or different speeds and the same or different temperatures. The barrel temperature for each extruder can be ramped in three zones from 325° F. to 375° F.; a fourth heater at the die/barrel connection can also be set to 375° F., and a fifth heater at the die can range from 375° F. to 400° F. Via rugged weldments the molten streams of the components are brought together to form the composite. Portion 46 can be precisely located on a portion (combination 44 , 48 , and 49 ) through accurately machined pathways in the die head. Because they have different compositions, the two molten materials are brought together at the last possible moment before exiting the die. Both materials exit the die head in a size and shape approximating that of the final product. The final dimensions are achieved using a series of forming rollers as the extrudate is cooled. The composite is typically extruded at a rate of 50 feet per minute.
The combined molten materials are drawn from the die head into the sizing/cooling device at a constant speed such that its cross section is always constant. Under a bath of cool dry air the molten material is cooled until no longer pliable. Once cooled, the composite can be cut to the appropriate length and attached to a razor cartridge.
Other examples of shaving aid composites may include the same composition for portions 44 , 48 , and connecting portion 49 , and a central portion ( 46 ) that contains about 90% of the composition used for portions 44 and 48 , plus the following:
Example A—1% blue pigment and 10% Aloe.
Example B—1% blue pigment and 10% Menthol.
Example C—10% Frescolat (a menthol analog).
Example D—10% Mineral-Oil/Vit. E.
Example E—10% Silicone fluid 1401.
Example F—5% Vit. E and 5% Panthenol.
Example G—10% Triclosan DP300 (an antimicrobial).
In other examples, portions 44 and 48 have the composition described above. The central portion contained the following percentages of the composition used in portions 44 and 48 (% Comp.), plus additional ingredients, as follows:
Example H—95% Comp. and 5% Triclosan DP300.
Example I—93% Comp. and 6% Menthol and 1%
Silicone copolymer
Example J—94% Comp. and 6% Menthol.
Example K—85% Comp. and 10% polyethylene oxide (60:40 Polyox blend previously used in portion 44 ) and 5% Salsorb.
In another example, central portion 46 may be composed of 80% Polyox (60:40 Polyox blend previously used in portion 44 ) and 20% nylon 12.
In another example, central portion 46 may contain the following ingredients:
Example L—80% Polyox (60:40 Polyox blend previously used in portion 44 ) and 14% polystyrene and 3% PEG 100 and 3% PVA.
Example M—70% amorphous nylon (Zytel 330) and 30% Polyox (60/40).
Example N—77.75% Polyox (60:40 Polyox blend previously used in portion 44 ) and 10% PEG 100 and0.25% Irganox and 2% green pigment and 10% Vit. E.
Other embodiments are within the claims. For example, referring to FIG. 4, a wedge-shaped shaving aid composite 56 includes lengthwise-extending portions 58 , 60 , and 62 , each including a lengthwise-extending exposed surface. Shaving aid composite 56 also includes connection portion 64 . Portions 58 , 60 , 62 , and 64 can have, for example, the same compositions as portions 44 , 46 , 48 , and 49 , respectively, and may be made by conventional co-extrusion or molding techniques. Shaving aid composite 56 can be attached to a shaving cartridge, e.g., the shaving cartridge used in Atra®, by gluing the composite to the recess in the cartridge.
Alternatively, referring to FIG. 5, the wedge-shaped shaving composite 64 may include two lengthwise-extending portions 66 and 68 . Portion 66 can contain 90% Comp., 1% blue pigment, and 10% Menthol or Aloe. Portion 68 can contain 100% Comp. with a small quantity of white pigment. The shaving aid composite shown in FIGS. 2 and 3 also may include only two lengthwise-extending portions. | A shaving unit includes a composite that has a surface for engaging the user's skin. The composite includes adjacent lengthwise-extending portions, each containing a shaving aid. | 0 |
REFERENCES TO RELATED APPLICATIONS AND PATENTS
[0001] The present invention claims priority, as it is a non-provisional application of a provisional patent application by the same inventors herein, filed on 28 Nov. 2012, and having a Ser. No. 61/730,870, and titled “A Universal Leveling Device That Protects Against Ground Moisture, Weed Whacking And Has Stackable Capabilities”.
BACKGROUND OF INVENTION
[0002] a. Field of Invention
[0003] The invention relates generally to the field of stabilizing, anchoring and leveling outdoor free standing structures, such as swing sets, elevated forts, wooden slides, gazebos, sheds, picnic tables, benches and the like. The legs or support structures of these products are subject to and often victims of the ground below them. Exposure includes uneven or sloped ground, ground moisture, weed whacking and mowing damage, rot and other problems. The present invention is a unique reversible support pad that performs numerous functions simultaneously and both protect the outdoor structures and reduce accidents sometime otherwise cause by tilted structures.
[0004] b. Description of Related Art
[0005] The following patents are representative of the field pertaining to the present invention:
[0006] U.S. Pat. No. 8,347,571 B2 to Fehr et al describes a structural column assembly of the type used for erecting building structures and the like that is bedded in a concrete footing formed in situ in an earthen hole. The column assembly includes a post whose bottom end is suspended above a floor of the hole by a stilt. The stilt includes a plurality of legs which extend from the post's bottom end and grip the hole floor through a plurality of cleats. The cleats help stabilize the column assembly during the concrete pour operation so that it does not shift out of position. The stilt legs are provided with a base pad, which is set below the bottom end of the post at a predetermined distance so that the concrete footing can be poured in a single operation immediately after the hole is formed. The stilt can accommodate posts made from wood, pre-cast concrete or any other known construction material. The stilts can be manufactured from formed flat steel or commercially available angle iron and channel stock.
[0007] U.S. Pat. No. 5,725,188 to Monteiro, Jr. describes a lawn chair leveling block includes a portable rigid, flat ground-engaging pad designed to support the lawn chair in a level position on a sloped ground surface. The pad is provided with an upstanding elevation block having a deep groove along a top surface, and the groove is designed to cradle a U-shaped leg of the chair. Blind holes positioned in the pad at opposite ends of the elevation block are designed to support individual tubular, vertical chair legs. In addition to being utilized for leveling a lawn chair on a sloped surface, the block prevents a chair leg from sinking into soft soil so as to eliminate the risk of the chair tipping over.
[0008] U.S. Pat. No. 5,427,342 to Gagnon describes a support is provided for positioning on the base of a wooden lawn furniture leg. The support has an area that is at least five times the area of the bottom of the leg to distribute the load over a large area. This permits easy sliding of the leg across a lawn. The support is arranged to prevent prolonged contact of the leg with a source of moisture. In addition, the support provides venting to the bottom of the leg to minimize dry-rot.
[0009] U.S. Pat. No. 5,141,076 to Joyce et al. describes a device to be used on the legs of standard wooden folding stepladders to insure the stability of said ladders while being used on weak, non-compacted or slippery areas, into which a stepladder might tend to sink, or across which a stepladder might tend to slide. Said device consists of a semi-rigid pad that when attached to the bottom of any or all of the legs of any standard wooden folding stepladder will then increase the stepladder leg footprint area resulting in more stability of said stepladder. In addition, the high friction material of which the stepladder foot pad may be constructed will tend to prevent the stepladder legs from slipping across slippery surfaces.
[0010] U.S. Pat. No. 4,915,335 to Miles describes a stabilizer for a lawn chair, sand chair, chaise lounge, as well as other similar chairs, which, in a first embodiment, has an adapter that readily fits over the front and/or rear lower horizontal tubing of the chair-frame, which adapter is provided with right-angled end-corners directly and laterally adjacent the rounded, curved ends of the respective lower horizontal tubing, where such lower horizontal tubing curve upwardly in transition to join with an upwardly, angularly-extending upright tubing of the chair-frame, whereby such curved ends, about which lateral tipping over typically occurs, are negated. In a second embodiment, the stabilizer of the invention snap-fits onto a lower horizontal tubing of the chair-frame, with such stabilizer also having a length greater than the length of the lower horizontal tubing, the ends of which stabilizer are provided with generally triangular-shaped, flat projections. The stabilizer is readily rotatable about the lower horizontal tubing to which is attached, so that the end-projections may be oriented at any desired angle. Thus, the flat end-projections may be oriented so that they lie flat against the ground when the chair is used on firm ground or cement, or may be oriented 90 degrees therefrom so that the pointed apices or corners of each flat end-projection faces toward the ground, which is especially useful when using a chair on soft sand.
[0011] U.S. Pat. No. 4,439,961 to Witte describes a leveling and locating or positioning device is disclosed which includes a force-bearing structure which is guided for vertical leveling movement by a vertical reference device which also provides a horizontal position reference. Horizontal movement of a tapered wedge device, which operatively interfaces with a sloped floor member of the force-bearing structure, causes vertical movement of the force-bearing structure and the resulting leveling function. A horizontal extender device, slidably mounted to and supported by the force-bearing structure, provides the horizontal locating or positioning function. A support device is operatively included or mounted to one end of the horizontal extender device and is configured to operatively interface with the member or device which is to be leveled and located or positioned.
[0012] U.S. Pat. No. 3,625,462 to Jordan describes the present invention relates to furniture joints and ground-engaging i.e. foot, members of furniture associated with such joints. There is provided a joint in an article of furniture between two interengaging members, the joint having a first part with an H cross section elongated element and a second part including a pair of bosses spaced apart by a distance generally equal to the width of the H central web. These joint parts are a push fit together and are bonded by a heat-treated resin adhesive. A ground-engaging member associated with one part of the joint is so curved that in an unloaded state only the end regions of the curve engage the ground whereas in a loaded state not only the end regions but also at least some intermediate regions engage the ground. There is also provided an improved method of making a part of the joint disclosed.
[0013] Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.
SUMMARY OF INVENTION
[0014] The present invention is directed to a universal leveling device for outdoor structures of wood and other vulnerable materials for leveling, stabilizing and protecting against ground hazard. The device includes a pad, the pad having a top, a bottom and at least one side wall, the pad having a first flat groove on its top, and having a second flat groove on its top, the second flat groove being positioned at a right angle to the first flat groove, the bottom having a first vee groove with two opposing angled walls, being a first wall having an angle of about 70 degrees to about 35 degrees from horizontal and a second wall having an angle of about 55 degrees to about 20 degrees from horizon, and having a second groove with two opposing walls, being a first wall having an angle of about 60 degrees to about 45 degrees from horizontal and a second wall having and angle of about 45 degrees to about 30 degrees from horizon.
[0015] In some embodiments of the present invention universal leveling device, the two grooves on the top of the pad are parallel to one another.
[0016] In some embodiments of the present invention universal leveling device, the top of the pad has horizontally flat corners and wherein the bottom of the pad has horizontally flat corners.
[0017] In some embodiments of the present invention universal leveling device, the top includes three flat grooves.
[0018] In some embodiments of the present invention universal leveling device, two of the three flat grooves are parallel to one another.
[0019] In some embodiments of the present invention universal leveling device, at least one of the grooves on the top of the pads traverses less than the full width of the top of the pad and has at least one end wall.
[0020] In some embodiments of the present invention universal leveling device, at least one of the grooves has two end walls.
[0021] In some embodiments of the present invention universal leveling device, at least one of the grooves on the top of the pads traverses the full width of the top of the pad and has no end walls.
[0022] In some embodiments of the present invention universal leveling device, the pad has a top view selected from the group consisting of square, rectangle, circle, oval and polygon of at least five sides.
[0023] In some embodiments of the present invention universal leveling device, the pad is made of a moisture resistant material selected from the group consisting of plastic, rubber, recycled tires and combinations thereof.
[0024] In some embodiments of the present invention universal leveling device, there is at least one ground-anchoring mechanism. In some embodiments of the present invention universal leveling device, the ground-anchoring mechanism includes at least one orifice through the pad for receiving an anchor.
[0025] In some embodiments of the present invention universal leveling device, the anchor is included and is selected from the group consisting of a rod, a nail, a pin, a coil pin and a bolt.
[0026] In some embodiments of the present invention universal leveling device, the anchor includes at least one attachment mechanism for attachment to the outdoor structures and at least one elongated earth penetrating member for insertion through the at least one orifice.
[0027] In some embodiments of the present invention universal leveling device, the pad is stackable with identical other pads. In some embodiments of the present invention universal leveling device, the pad further includes at least one stacking stabilizer. In some embodiments of the present invention universal leveling device, the pad has a plurality of stacking stabilizers on the top and a plurality of stacking stabilizers on the bottom. In some embodiments of the present invention universal leveling device, the plurality of stacking stabilizers are a combination of nesting protrusions and recesses.
[0028] In some embodiments of the present invention universal leveling device, there are a plurality of stacking stabilizer recesses on one of the pad top and the pad bottom, and plurality of complementary stacking stabilizer protrusions on the other of the pad top and the pad bottom.
[0029] In some embodiments of the present invention universal leveling device, there are four stacking stabilizer recesses on one of the pad top and the pad bottom, and four complementary stacking stabilizer protrusions on the other of the pad top and the pad bottom.
[0030] Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims.
[0031] Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS(S)
[0032] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the detail description serve to explain the principles of the invention. In the drawings:
[0033] FIG. 1 is a perspective front view of one embodiment of the present invention universal leveling device showing multiple flat grooves on its top;
[0034] FIG. 2 shows the present invention leveling device of FIG. 1 with a right angled play fort leg contained therein;
[0035] FIG. 3 shows the same present invention universal leveling device as shown in FIG. 1 , but in a reverse position with its bottom facing up and revealing two vee grooves;
[0036] FIG. 4 shows the present invention universal leveling device of FIG. 3 , but supporting a 45 degree angled support member of a swing set;
[0037] FIG. 5 shows the present invention universal leveling device of FIG. 3 , but supporting a 60 degrees angled support member of a swing set;
[0038] FIG. 6 shows an alternative present invention universal leveling device with multiple protruding stacking stabilizers;
[0039] FIG. 7 shows the obverse of FIG. 6 with the present invention leveling device having recessed stacking stabilizers;
[0040] FIG. 8 shows two of the FIG. 6 / FIG. 7 present invention universal leveling devices in a stacked position;
[0041] FIG. 9 shows a front perspective view of another present invention universal leveling device that has a rectangular shape;
[0042] FIG. 10 and FIG. 11 show variations of present invention universal leveling devices, with one end open and one end closed, of a flat groove and a vee groove, respectively; and,
[0043] FIG. 12 shows a block diagram listing some of the preferred embodiment features of present invention universal leveling devices.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0044] Referring now in detail to the drawings wherein like reference numerals designate corresponding parts throughout the several views, various embodiments of the present invention are shown.
[0045] FIG. 1 is a perspective front view of one embodiment of the present invention universal leveling device 1 . It includes a front wall 3 , a back wall 5 , a left wall 7 , a right wall 9 , a top 11 and a bottom 13 . Device 1 has an anchoring orifice 21 which may be used to insert an anchor member therethrough. Any anchoring device that may be hammered or otherwise forced into the ground may be used, but a rod such as a rebar with a welted large washer at one end is preferred. Such as anchoring device may be used to position and hold a present invention universal leveling device in place while a screw may be inserted into the washer into a wooden structure leg to help stabilize and maintain its position.
[0046] Top 11 of universal leveling device 1 has two parallel flat grooves 17 and 19 that intersect at right angles with flat grooves 15 . Flat groove 15 has both ends open, but could alternatively have one end or both ends closed. These flat grooves are created to receive bottom ends of upright (vertical) legs or supports for such structures as elevated forts, slides and swing sets. Alternatively, they could be used to level or stabilize small unanchored structures such as sheds and gazebos. Also shown in FIG. 1 is a portion of vee groove 23 on bottom 13 , which will be discussed in conjunction with FIGS. 3 , 4 and 5 , below.
[0047] FIG. 2 shows the present invention leveling device 1 of FIG. 1 with a right angled play fort leg contained therein. The leg includes a first upright 12 connected to a second upright 14 . These uprights conveniently fit into flat grooves 15 and 19 , as shown. The universal leveling device 1 performs a number of functions. First, it creates a level surface for an outdoor structure. Second, it may be used to elevate one or more corners of a structure to bring the entire structure into a vertical or horizontal position from a tilt. Third, it creates a moisture barrier between the ground and the outdoor structure. Forth, it protects the outdoor structure from weed whacker and lawnmower damage. Fifth, when stacked, the devices will eliminate a free moving corner on the downside of a hill or recess in the ground. Sixth, in some cases, they eliminate the need for and work involved in concrete bases or footings. In flat environments, one present invention device for each corner of a structure is ideal. If the structure needs leveling, it is preferred to use at least one device under each corner and additional stacked units where additional elevation is need.
[0048] FIG. 3 shows the same present invention universal leveling device 1 as shown in FIG. 1 , but in a reverse position with its bottom 3 facing up and revealing two vee grooves. Vee groove 25 is closed at both ends and one side may have a 45 degree angle while its opposite side may have a 60 degree angle. It may range from 35 to 70 degrees. This vee groove 25 also includes anchoring orifice 21 . A tilted 4 inch by 4 inch post support may be positioned in vee groove 25 , an anchoring rod with washer may be passed through orifice 21 and hammered into the ground with the washer bolted, nailed or screwed onto the two by four support. Vee groove 23 is open on both ends and may be used for tilted linear supports. For example, FIG. 4 shows the present invention universal leveling device 1 of FIG. 3 , but supporting a 45 degree angled support member 22 from a swing set. Another example is FIG. 5 which shows the present invention universal leveling device 1 of FIG. 3 , but supporting a 60 degrees angled support member 24 .
[0049] FIG. 6 shows an alternative present invention universal leveling device 51 with multiple protruding stacking stabilizers 83 , 85 , 87 and 89 . It includes a front wall 53 , a back wall 55 , a left wall 57 , a right wall 59 , a top 61 and a bottom 63 . Device 51 has an anchoring orifice 71 which may be used similarly to orifice 21 described above in conjunction with the prior Figures. Top 61 of universal leveling device 51 has two parallel flat grooves 57 and 69 that intersect at right angles with flat groove 65 . These flat grooves function in the same manner as those flat grooves described above. The protruding stacking stabilizers 83 , 85 , 87 and 89 are symmetric, as shown, so that stacking may occur with receiving recess stacking stabilizers with and of four orientations, i.e., the stacked devices need not have the grooves aligned. However, alignment is necessary where the orifice 71 is utilized on all stacked devices. (An anchor could pass through only the bottom orifice of a stack, but will preferably penetrate all devices in a stack.)
[0050] FIG. 7 shows the obverse of FIG. 6 with the present invention universal leveling device 51 , revealing receiving, recessed stacking stabilizers 93 , 95 , 97 and 99 , corresponding and position and size to protrusions 83 , 85 , 87 and 89 of FIG. 6 , to create optimal stacking and nesting, as needed.
[0051] FIG. 8 shows two of the FIG. 6 / Figure 7 present invention universal leveling devices 51 in a stacked position, designated as devices 51 A and 51 B. as many devices may be stacked as needed, until stability becomes an issue, e.g., two, three or four may be used.
[0052] FIG. 9 shows a front perspective view of another present invention universal leveling device 101 that has a rectangular shape, instead of a square shape. Any other shape may be used for a top view footprint without exceeding the scope of the present invention.
[0053] FIG. 10 and FIG. 11 show variations of present invention universal leveling devices 110 and 112 , respectively, with one end open and one end closed, of a flat groove in FIG. 10 and a vee groove in FIG. 11 , respectively.
[0054] FIG. 12 shows a block diagram listing some of the preferred embodiment features of the present invention universal leveling device 120 . These include block 122 , listing some preferred shapes; block 124 describing angled (vee) grooves; block 126 describing flat grooves; and block 128 showing anchoring options.
[0055] The devices of the present invention are generally made of waterproof or water resistant materials, such as recycled rubber/tire chips melted and heat bound into the desired forms, rubber, recycled plastic, plastic, mixes of the foregoing, strong foams, such as micro-porous urethane, composite materials and other functional choices. Further, the present invention universal leveling devices may structurally be homogeneous or contain diverse materials. For example, they made have strengthening elements impeded therein, e.g., rigid foam with plastic or metal pieces, rods or plates. Further, although the exact overall shapes are not critical, the grooves should be designed for supported structure compatibility and the tops and bottoms should have flat corner areas, as shown, to enhance stacking capabilities.
[0056] Although particular embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those particular embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A universal leveling device for outdoor structures of wood and other vulnerable materials for leveling, stabilizing and protecting against ground hazards, has at least a first and a second flat groove on its top, at right angle to each other, and on its bottom has first and second vee grooves each with two opposing angled walls. The reversible device can accommodate vertical and tilted support structures. | 4 |
BACKGROUND OF THE INVENTION
[0001] A windmill, with airfoil blades, must start its motion with the airfoil blades in an aerodynamic stall condition. In order to produce a substantial measure of torque on a windmill airfoil blade, the leading edge of the blade must be looking up wind, the blade chord is placed acutely to the wind face and the longitudinal axes of the blades are arranged to rotate perpendicular to the wind face. Essentially, the wind velocity pressure present on the acute up wind surface of the airfoil blades (side facing up wind) must drive the airfoil blades to a speed sufficient to cause a boundary layer to flow across the down wind cambered surface (side facing down wind) of the airfoil blade with enough force to produce the required dynamic lift force.
[0002] Horizontal axis windmills with airfoil type blades, are well suited for use as prime movers in the production of electricity. However, as with all machines, each has its own set of characteristics. Windmills are extremely noisy, especially when operating under heavy loads. Some of the noise associated with windmills indicate the inefficiencies of the machine. For example, blade tip flap or flutter is associated with a wind shear condition, where the wind will shear and flow up from the earth's surface through the rotating windmill blades at acute angles causing a tendency for the blade tips to move back and forth across the plane of rotation. This indicates a difference in the amount of dynamic lift force (torque) produced by each blade as it rotates and passes through the wind shear. The difference in torque causes a fluctuating bending tendency along the longitudinal axes of the blade, and a fluctuating bending tendency to the drive shaft, i.e. a fluctuating yaw tendency to the tower structure. This condition obviously requires the use of thicker, heavier, less efficient blades, and a heavier tower structure, effecting cost, etc.
[0003] The wind velocity surface pressure on the up wind sides of the torsion pivot blades, is held at equilibrium from tip to tip across the entire disc of rotation, by means of a free turning torsion shaft and the dynamic torsion coupling effect of the blades interacting with the wind, i.e. there will be zero yaw force, blade flap, and zero bend to the driveshaft.
[0004] Windmills with airfoil type blades have a high tip speed ration, and are suitable as prime movers for electric generators, but unless the windmill is placed on an ideal wind site, such as the trade winds of Hawaii, where wind at some locations is almost constant at twenty to thirty M.P.H (miles per hour), one may find the airfoil blades on their windmill idle a great deal of time.
[0005] Energy in the wind is the air particles in motion, (momentum). Anything placed in motion has momentum. The energy (momentum) in the wind can essentially be determined by the number of air particles found in a given space, (density), and how fast the air particles are moving, (velocity).
[0006] The wind will cause a pressure against the surface of any solid object placed perpendicular (at right angles) to the wind face, which pressure is referred to as “wind velocity surface pressure” and each time the wind velocity is doubled, the wind velocity pressure will essentially quadruple against the surface of any such object, which surface would be the side of the object looking upwind, (the upwind side).
[0007] A typical wind electric generator appropriately placed on a site where if the wind is blowing at a rate of a five miles per hour, (M.P.H.) the airfoil blades would be idle, but if the wind suddenly increased to ten (M.P.H.) the blades will not only spin but will produce electric energy. Whereas if the wind velocity doubles the wind energy will essentially quadruple, (a phenomenon).
[0008] The wind interacting with the airfoil blades of a windmill will cause a dynamic lift to the blades, and the blades will start to spin. When the blades are put into motion and gather speed they will gather momentum (energy) and the energy from the spinning blades will turn a driveshaft which driveshaft turns the electric generator. The motion is relative, combining the torque of the spinning blades with the dynamic lift force, which force is caused by the interaction of the blades with the wind.
[0009] The motion of the blades is essentially a spinning motion, but the movement is the wind particles where the wind particles will approach the blades, interact with the blades, and move past the blades. The movement is relative.
[0010] The spinning airfoil blades of a typical wind generator will rotate through a wind mass in a helical track resembling the threads of a machined screw. Whereas the relative speed of the rotating blades is greater at the blade tip end, than at the blade root end, and the relative blade pitch angle should reflect a helical track which at the time of blade construction would be accomplished by twisting the blade chord at each station of the blade, starting from the blade root end, and extending to the blade tip end.
[0011] The relative blade pitch angle is the acute angle at which the blade chord is placed relative to the plane of blade rotation, as seen from the blade tip end.
[0012] “The critical angle”, is essentially, where the relative angle of attack becomes so steep to cause the airfoil to lose dynamic lift and the airfoil will stall.
[0013] When the relative speed of an airfoil decreases to a certain point, and the blade chord is at a certain relative blade pitch angle, which relative blade pitch angle becomes so steep where the air particles which are moving around the leading edge of the airfoil blade and accelerating in a boundary flow across the downwind cambered side will pull away from the blade surface.
[0014] Whereas the boundary flow, when at the correct relative angle (angle of incidence) will cause the rarefaction of air particles on the downwind cambered surface of the blade, which action causes the dynamic lift, but when the boundary flow pulls away form the blade surface, the blade will lose the dynamic lift, and the blade will stall (“critical angle”). In this arrangement, the “angle of incidence” refers to the angle at which the accelerated air particles strike the surface of the down wind side of the blade.
SUMMARY OF THE INVENTION
[0015] Wind generators with airfoil blades are suitable as prime movers for electric generators, but because of the critical angle factor the starting torque is practically zero, and the low end run torque is poor. One reason, as previously described, is the critical angle factor, where the airfoil must start its motion from an aerodynamically stalled condition, and another reason is (i.e.) narrow airfoil blades have less deflection than wide blades, such as water pumpers. Wind generators with airfoil blades work well on ideal wind sites, but not as well on sites where the wind speed is less and the wind will quite often shear and shift direction.
[0016] The lift enhancement gate valve will tend to regulate the angle of incidence of the accelerated boundary flow of air across the down wind cambered surface of an air foil blade, thereby enhancing the dynamic lift characteristics of the blade, especially in low to moderate winds. The pivot blade of the subject invention with the lift enhancement gate valve will address the wind shear problem and the critical angle factor.
[0017] These and other features and objectives of the present invention will now be described in greater detail with reference to the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an operational view of the windmill;
[0019] FIGS. 2 , 3 and 4 are exploded views of the variable pitch torsion shaft assembly;
[0020] FIG. 5 is an exploded view of the airfoil pivot blade and airfoil tip blade;
[0021] FIG. 6 is a top plan view of the airfoil pivot blade and the airfoil tip blade;
[0022] FIG. 7 is plan view showing the upwind surfaces of the airfoil pivot blades and the lift enhancement gate valve;
[0023] FIG. 8 is an exploded view of the lift enhancement gate valve.
[0024] FIG. 9 is an end view of the lift enhancement gate valve arrangement; .and
[0025] FIG. 10 is an operational view of the lift enhancement gate valve arrangement attached to section of the air foil rotary blade;
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1 , when affixed to opposite ends of a free turning torsion shaft, in a certain way, the blade chords will be offset from one another, establishing a blade pitch angle.
[0027] Referring to FIG. 7 , airfoil tip blades 124 - a , 124 - b are placed at the outer most trailing edge section of the airfoil blades 92 - a , 92 - b , such that the longitudinal axes of airfoil tip blades 124 - a , 124 - b are placed at acute angles to the longitudinal axis of the torsion shaft, line R-R. Referring to FIGS. 1 and 2 , torsion shaft 12 ( FIG. 2 ) is placed in the plane of rotation, such that it will be permitted to simultaneously rotate end over end and turn 360 degrees around its own axis, R-R. ( FIG. 1 ) This arrangement provides a dynamic torsion coupling effect, whereas the wind velocity surface pressure applied to the upwind surface of one airfoil tip blade, 124 - a or 124 - b , causes the airfoil blades 92 - a and 92 - b to pivot, and turn the torsion shaft 12 , via the shaft sleeves 14 - a and 14 - b , as shown in FIGS. 1 , 2 , 3 , 4 and 7 .
[0028] In FIG. 1 , when the wind approaches the airfoil blades such that the disc of rotation is at a right angle to the wind, the quantity of surface area seen on the upwind side of airfoil blade 92 - a and airfoil tip blade 124 - a , is equal to the surface area seen on the upwind side of airfoil blade 92 - b and airfoil tip blade 124 - b , i.e. the blades rotates, but will not reciprocate (pivot). However, as example, if the wind shears and moves up from the earth surface such that it will approach the disc of rotation at an acute angle, the wind will see a greater quantity of surface area on the airfoil blade 92 - a , and airfoil tip blade 124 - a . Whereas, the wind velocity surface pressure will be greater on airfoil blade 92 - a and airfoil tip blade 124 - a , which causes the airfoil blades to pivot, and the blade chords, line B-B, reciprocates as the blades continue to rotate through the wind shear.
Assembly and Operation
[0029] Referring to FIG. 2 , the torsion shaft sleeves 14 - a , 14 - b are suspended by the collar thrust against bearings 26 - a , 26 - b (only one shown) via bearing blocks 42 - a , 42 - b , which shaft sleeves 14 - a , 14 - b will all times be free to turn unfettered. The airfoil blades 92 - a , 92 - b , essentially attach to the shaft sleeves 14 - a , 14 - b , via the blade root base plates 32 - a , 32 - b , see FIGS. 2 , 3 , and 4 .
[0030] Referring to FIG. 3 , the flexible shaft 104 of servo unit 110 fastens to the spring torsion shaft 12 , with pin fasteners 90 - a , via torsion shaft coupler link 22 , and torsion shaft coupler 20 - a . The shaft coupler 20 - a has a bearing surface which fits and turns inside torsion shaft bearing 24 - a . The bearing 24 - a press fits into the (seat 144 - a ) of the torsion shaft sleeve w/collar 14 - a and likewise the torsion shaft coupler 20 - b , ( FIG. 2 ) has a bearing surface which fits and turns inside torsion shaft bearing 24 - b , which bearing 24 - b , press fits into the seat 144 - b of torsion shaft sleeve w/collar 14 - b . The spring torsion shaft 12 , ( FIGS. 2 and 3 ) fastens at one end, at servo unit 110 with coupler link 22 and pin fastener 90 - a . The other end of the spring torsion shaft 12 , ( FIG. 4 ) couples to the spring loaded keyed shaft of the coupler solenoid 114 via the slotted torsion shaft flexible coupler 106 at airfoil blade 92 - b w/pin fastener 90 - b.
[0031] To simplify the drawings of FIGS. 3 and 4 , (exploded views) only one torsion shaft sleeve bearing block 42 is shown in FIG. 2 . Torsion shaft sleeve bearing block 42 - b and related like parts, is not shown, but are identical and will assemble in the same fashion as torsion shaft sleeve bearing block 42 - a.
[0032] Referring to FIG. 3 , this view shows the torsion shaft sleeve w/collar 14 - a , which sleeve 14 - a is placed inside the torsion shaft sleeve bearing block 42 - a , which sleeve bearing block 42 - a is placed inside the torsion shaft housing sleeve 18 . Only two of four screw fasteners 70 - a are shown. The screw fastens 70 - a fastens the torsion shaft sleeve bearing block 42 - a to the torsion shaft housing sleeve 18 .
[0033] Referring to FIG. 4 , there are two of four screw fasteners 70 - b shown, which screw fasteners 70 - b , fasten the sleeve bearing block 42 - b , into place, which sleeve bearing block 42 - b , and related bearing slide fit over the torsion shaft sleeve w/collar 14 - b , and the collars of both, torsion shaft sleeve w/collar 14 - a and 14 - b , can butt against one another inside torsion shaft housing sleeve 18 . The face surface of the collars of shaft sleeves 14 - a and 14 - b are low friction, such as Teflon, i.e. if the windmill 10 , ( FIG. 1 ) has an emergency shutdown, where the coupler solenoid 114 ( FIG. 4 ) uncouples the airfoil blades 92 - a , 92 - b , from one another, via the spring torsion shaft 12 , and if the computer has parked the airfoil blades 92 - a , 92 - b , such that their longitudinal axis are placed in the vertical plane, the wind vane effect, where, the wind velocity pressure acting on the surface of the airfoil tip blades 124 - a , 124 - b (torsion lever effect) can turn the blades 92 - a , 92 - b , to the feather.
[0034] When the windmill blades are in operation, the collars of shaft sleeves 14 - a , 14 - b are thrust against the sleeve bearing blocks 42 - a , and 42 - b , via the related bearings, and there is a small space between the related collar butt surfaces, of less than one eighth of one inch.
[0035] Referring to FIG. 3 , the view showing, torsion shaft sleeve w/collar 14 - a , assembled with sleeve bearing block 42 - a , which bearing block 42 - a is fastened inside the housing sleeve 18 , which screw fasteners 70 - a (two of four shown). The sleeve seal 46 - a seals the related bearings from the outside. The torsion shaft bearing 24 - a press fits against the bearing seat 144 - a , the bearing seal 28 - a seals the bearings 24 - a.
[0036] Referring to FIGS. 2 , 3 , and 4 , the electrical brush block 58 - a , which fastens to the torsion shaft housing sleeve 18 by using screw fasteners 74 - a (only one shown) is the manner in which the shielded electrical wiring 52 - a attaches to the electrical brush 64 - a with screw fasteners 76 - a , and stand-off spacer sleeve 140 . For the purpose of illustration, the shape and number of electrical brushes 64 - a and 64 - b , and electrical slip rings 54 - a , 54 - b are identical, however, it should be understood that, the number of electrical slip rings, brushes and necessary wiring can vary as may be required, but the general shape and manner of attachment will remain the same.
[0037] The view in FIG. 4 , shows the electrical conduit 130 - b , the rain tight seal 134 - b , the shielded wiring 52 - b , the electrical brushes 64 - b , and the electrical brush block 58 - b , which brush block 58 - b is attached to the torsion shaft housing sleeve 18 , using screw fasteners 74 - b . The rain tight electrical brush cover sleeve 126 - b , slide over the rain tight seal 134 - b and up on to the shaft housing sleeve 18 , such that the electrical brushes 64 - b is accessible. The blade root base plate 32 - b , the rain tight electrical brush cover w/lip 122 - b , and non conductive electrical slip ring stem 38 - b fastens to the blade root base plate stem 36 - a . The electrical slip rings 54 - b attaches in typical fashion to the electrical slip ring stem 38 - b . The shielded electrical wiring 52 - b fastens in a typical manner to the electrical slip ring 54 - b , which shielded electrical wiring 52 - b , then passes through the chase 50 - b in the blade root base plate 32 - b . The electrical brushes 64 - b , have a typical spring characteristic. The blade root base plate stem 36 - b will light drive fit over the protruding end of the torsion shaft sleeve w/collar 14 - b , and a tool is used to lift the electrical brushes 64 - b , such that the electrical slip rings 54 - b slide beneath the electrical brushes 64 - b . The blade root base plate stem 36 - b attaches to torsion shaft sleeve w/collar 14 - b , with screw fasteners 72 - b (only one shown). When the tool is removed from the electrical brushes 64 - b , the spring action causes the electrical brushes 64 - b to press against the electrical slip rings 54 - b i.e. to make electrical contact.
[0038] The small end of the rain tight electrical brush cover sleeve 126 - b is plastic coated and slide fits around the rain tight electrical brush cover w/lip 122 - b , and butts the over hang portion of the lip. The large end of the rain tight electrical brush cover sleeve 126 - b fastens to the torsion shaft housing sleeve 18 , at the rain tight seal 134 - b , with screw fasteners 80 - b (only one shown). Compare like parts rain tight electrical brush cover sleeve 126 - a , 126 - b and brush cover w/lip 122 - a , 122 - b . This arrangement permits the torsion shaft sleeves w/collar 14 - a , and 14 - b to turn freely inside the rain tight brush cover sleeves 126 - a and 126 - b.
[0039] In FIG. 2 , the leaf springs of the spring torsion shaft 12 , fasten to the torsion shaft couplers 20 - a , and 20 - b with pin fasteners 90 - a and 90 - b and simply slides through the centers of sleeves 14 - a and 14 - b , as is shown in FIG. 2 and FIG. 4 , via the torsion shaft bearings 24 - a and 24 - b . Referring to FIGS. 2 and 3 , the three spars 84 - a of the airfoil blade 92 - a , attaches to the blade root base plate 32 - a , in such a way that the protruding end of the blade root base plate stem 36 - a extends into the root rib aperture 148 - a of the blade root base rib 88 - a . Only one of the three spars 84 - a is shown along with the necessary parts to demonstrate how the airfoil blade 92 - a fastens, the two other spars 84 - a , uses like parts, and fastens in the same manner. Such that the spar shim plates 60 - a slide fits over the protruding end of blade spar 84 - a . The elastic blade spar shock sleeves 66 - a , are constructed of metal bands and elastic, which blade spar shock sleeves 66 - a press fits into the spar sleeves 86 - a , of blade root base plate 32 - a . The blade spars 84 - a tight slide fits through the shock mount sleeves 66 - a , blade spar shim plate 62 - a slide fits over the end of the blade spars 84 - a and the blade and the blade spar retaining pins 56 - a , drive fits through the blade spar retainer pin slots 102 - a , such that the blade root base rib 88 - a are drawn tight against the blade spar shim plates 60 - a.
[0040] Airfoil blade 92 - b , uses like parts, which parts are used with airfoil blade 92 - a , airfoil blade 92 - b attaches and fastens in the same manner as that which was described for airfoil blade 92 - a.
[0041] The access panel cover 94 - a , FIG. 3 , is self explanatory, it attaches using screw fasteners 82 - a . The servo unit 110 attaches to the blade rib bulkhead 100 - a with screw fasteners 68 (only one shown). The shielded wiring 52 - a attached to the servo unit 110 , passes through the wiring chase 50 - a in the blade rib bulkhead 100 - a . The shielded wiring 52 - a attached to the electrical slip rings 54 - a is shown in FIG. 4 , which wiring passes through the wiring chase 50 - a in the blade root base plate 32 - a and the wiring chase 50 - a in the blade root base rib 88 - a , where the electrical joints are made inside the airfoil blade 92 - a.
[0042] The torsion shaft coupler link 22 , via the root rib aperture 148 - a , fastens the flexible shaft 104 of the servo unit 110 to the torsion shaft coupler 20 - a with pin fasteners 90 - a , i.e. the spring torsion shaft 12 , is fastened at one end only, which is to the airfoil blade 92 - a via the housing of the servo unit 110 .
[0043] The end of spring torsion shaft 12 , FIGS. 2 and 4 , which attaches to the shaft coupler 20 - b , which shaft coupler 20 - b attaches to the torsion shaft flexible coupler 106 with pin fasteners 90 - b , via the aperture 148 - b of the blade root base rib 88 - b ( FIG. 4 ). The slotted end of the torsion shaft flexible coupler 106 , loose slide fits into the torsion shaft flexible coupler guide sleeve 118 , which guide sleeve 118 , can be constructed using spun glass reinforced nylon, and attached to the blade rib bulkhead 100 - b with epoxy resins. The purpose of the coupler guide sleeve 118 is to provide a means of support for the slotted end of the torsion shaft flexible coupler 106 , in such a way as to effect the alignment of the keyed shaft of the coupler solenoid 114 , and the key-way slot of the flexible coupler 106 . The coupler solenoid 114 attaches to the blade rib bulkhead 100 - b with screw fasteners 78 and standoff spacer sleeves 142 (only one of each shown), such that the small end of the keyed shaft of the coupler solenoid 114 , extends far enough into the shaft guide sleeve 118 to effect a coupling with the torsion shaft flexible coupler 106 .
[0044] The coupler solenoid 114 , as constructed, has a typical electrical wiring scheme, FIG. 4 , a keyway slot in the solenoid housing and a key in the shaft, which key permits the shaft to slide into, and out of the solenoid housing, but will not permit the shaft to turn. The end of the shaft of the coupler solenoid 114 has a shaft key and is machined to a smaller diameter than that of the shaft which diameter permits the shaft to loose slide fit into the end of the torsion shaft flexible coupler 106 , and when coupled the key and slot arrangement prevents the shaft from turning.
[0045] FIG. 4 , the shaft of the coupler solenoid 114 , is spring loaded such that when the solenoid electrical winding is de-energized, the shaft is thrusted against a stop inside the solenoid housing, which causes the shaft to extend from the housing, i.e. The spring pressure on the coupler solenoid shaft 114 , permits the servo unit 110 , to turn the flexible coupler 106 such that when the key of the coupler solenoid shaft 114 finds the key way slot of the flexible coupler 106 , the torsion shaft 12 , effectively couples together the airfoil blades 92 - a and 92 - b , and the relative position of the blade chords will be the same each time the blades are coupled.
[0046] The coupler solenoid 114 has a typical centrifugal switch arrangement, (not shown) where basically, a measured weight is placed against a spring tension such, that when the spinning weight reaches a certain gravity force, which gravity force causes the spinning weight to over ride the spring tension, i.e. actuating the electrical switch.
[0047] The electrical wiring 52 - b is the shielded electrical wiring for the coupler solenoid 114 , which solenoid 114 is attached to the airfoil blade 92 - b , as previously described. The shielded wiring 52 - b is like the shielded wiring 52 - a , which wiring 52 - a was previously described for the servo unit 110 , which servo unit 110 is attached to the airfoil blade 92 - a . The wiring 52 - a and 52 - b , has like parts, electrical slip rings 54 - a and 54 - b , electrical brushes 64 - a and 64 - b , electrical conduit 130 - a and 130 - b , electrical wiring chase 50 - a and 50 - b , which chase is through like parts, blade rib bulk heads 100 - a and 100 - b , blade root base ribs 88 - a and 88 - b , blade root base plates 32 - a and 32 - b . The wiring 52 - a and 52 - b attaches in the manner as previously described.
[0048] As shown in FIG. 1 , the windmill driveshaft axle 48 , has a flange 44 - b which flange 44 - b , is like the flange 44 - a , but slides over the end, and on to the driveshaft axle 48 , such that when the flange 44 - b is welded to the driveshaft axle 48 , the end portion of the driveshaft axle 48 , extends beyond the face of the flange 44 - b , which end portion of the driveshaft axle 48 machine to an outside diameter, which diameter, matches the machined inside diameter of the driveshaft housing sleeve 40 , which housing sleeve 40 , has a welded flange 44 - a . The driveshaft housing sleeve 40 , slide fits over the machined end of the driveshaft axle 48 , such that the flange 44 - a attaches to the like flange 44 - b in a typical fashion with dowel fastener (not shown) and bolts.
[0049] The shielded wiring 52 - a , 52 - b (shown in FIG. 4 ) passes through conduit 130 - a , 130 - b , the driveshaft housing flange 44 - a , and the like flange 44 - b , ( FIG. 1 ) attach in typical fashion to an electrical slip ring arrangement (not shown), and are placed on the driveshaft axle 48 inside the nacelle 150 . The typical electrical arrangement attaches the necessary wiring to the electric switches and computer controls, are located inside the windmill nacelle 150 , (not shown). The computer and electric switched controls the electric current flow to the servo unit 110 , (shown in FIG. 3 ) and the uncoupler solenoid 114 .
[0050] FIGS. 1 , 2 , 3 and 4 , the computer (not shown) and the servo unit 110 , via the spring torsion shaft 12 , control the relative blade pitch angle, (the relative acute angle at which the blade chords are presented inclined to the wind,) which relative blade pitch angle is seen as lines drawn from B-B in FIG. 1 . As previously described, the housing of the servo unit 110 , is attached to the airfoil blade 92 - a , the flexible shaft 104 of the servo unit 110 , is attached to the spring torsion shaft 12 , such that when the servo unit is electrically energized the magnetic torque from the servo motor causes the housing of the servo unit 110 , to move (turn) in one direction, and cause the flexible shaft 104 , to turn in the opposite direction from that of the servo unit housing.
[0051] FIGS. 1 , 2 , 3 and 4 , the spring torsion shaft 12 , extends through the shaft assembly, 156 , and attach to the airfoil blade 92 - b via the uncoupler solenoid 114 . The airfoil blades 92 - a , 92 - b , are attached to the free turning torsion shaft sleeves 14 - a , 14 - b , i.e. The computer may cause the airfoil blades 92 - a , 92 - b , to turn such that the blade chords B-B in FIG. 1 , can turn in opposite directions from one another 360 degrees around the axis R-R, which effects the relative blade pitch angle from zero degrees to the feather position. This arrangement (as previously described) will also allow the longitudinal axis of spring torsion shaft 12 , to turn end over end in the plane of rotation with the airfoil blades 92 - a , 92 - b , The airfoil blades 92 - a , 92 - b rotate perpendicular to the windface, and around the driveshaft axle 48 , i.e. the spring torsion shaft 12 , can turn inside the torsion shaft sleeves w/collar 14 - a , 14 - b and can simultaneously reciprocate with the torsion shaft sleeves w/collar 14 - a , 14 - b , via slip rings 54 - a and electrical brush, 64 - a ( FIGS. 2 , 3 , and 4 ).
[0052] As previously described, the torsion shaft sleeves w/collar 14 - a , 14 - b , along with the attached blades 92 - a , 92 - b , the servo unit 110 , the spring torsion shaft 12 , coupling links, and coupler solenoid 114 , are free to turn around the axis R-R, i.e. when the airfoil blades 92 - a , 92 - b , are uncoupled from one another, the blade chords B-B are aligned with the wind and the airfoil tip blades 124 - a , 124 - b , are aligned downwind, such that, the airfoil tip blades 124 - a , 124 - b , will have a wind vain effect, which keeps the blade chords B-B aligned with the wind, (the feather position). i.e. It would not be necessary to turn the windmill into the wind, until the storm has passed and the prevailing wind returned.
[0053] The dynamic torsion coupling effect is restored when the windmill 10 , is turned into the wind and the airfoil blades 92 - a , 92 - b are turned such that the blade chords B-B are placed at acute angles to one another, where the surfaces on the upwind side of the airfoil blades 92 - a , 92 - b , are inclined to the wind face.
[0054] In an emergency condition, the coupler solenoid 114 , as previously described, is a means for effectively uncoupling the airfoil blades 92 - a , 92 - b from one another, and shutting the windmill down. The solenoid 114 uncouples via the motion switch (not shown), when a catastrophe, causes the tower to shake. A runaway blade is a condition where the blade can rotate at a speed beyond the design limits of the blade. As an example, where the load to the windmill driveshaft is suddenly lost, the computer would normally sense the condition, adjust the relative blade pitch angle and or shut the windmill down. However, if the computer fails, the centrifugal switch, located in the coupler solenoid, will, as previously described uncouple the blades from one another and shut the windmill down. When the airfoil blades 92 - a , 92 - b are uncoupled from one another, and a break applied to the driveshaft 48 , FIG. 1 , the wind vain effect as previously described causes the blades to turn to the feather position.
[0055] A windmill which is in operation and generating electricity, will typically experience routine subtle load shifts to the blades, where a sudden change in power demand or a sudden gust in wind velocity, causes the relative load to fluctuate. The flexible shaft 104 ( FIGS. 3 and 4 ), of the servo unit 110 , the flexible shaft coupler 106 , and the blade spar elastic shock sleeves 66 - a and 66 - b , are arranged such as to permit the airfoil blades 92 - a , 92 - b , to flex, such that the elastic shock sleeves 66 - a , 66 - b permits the blades 92 - a , 92 - b , to bend down wind by an amount which will effectively handle the shock of most routine load shifts.
[0056] In a catastrophic load shift condition, such as previously described, the spring torsion shaft 12 , FIGS. 2 and 3 , permits the blades to twist toward the feather position, which action releases wind velocity pressure i.e. avoiding blade shear at the point of attachment. This arrangement permits the spring torsion shaft 12 to have enough spring resilience (to be stout enough) to control the relative blade pitch angle, and permits the blades to pivot and reciprocate, without oscillating, so that this arrangement permits the spring torsion shaft 12 , to respond to the extreme catastrophic load shifts and permits the elastic shock sleeves 66 - a , 66 - b , to respond to routine load shifts.
[0057] For the purpose of illustration, FIG. 5 shows a scheme for constructing the airfoil blade 92 - a , using ribs and spars. The airfoil blade 92 - b would be an exact duplicate of the airfoil blade 92 - a , using like parts.
[0058] The blade spars 84 - a are equal in diameter, and have an appropriate taper from root to tip.
[0059] The blade spars 84 - a can be constructed in a typical fashion, using composite fibers and a laminated hardwood core, which core extends through the blade root base rib 88 - a and the blade rib bulkhead 100 - a ( FIG. 3 ). A stainless steel sleeve can be placed over and bonded to the protruding ends of the blade spars 84 - a.
[0060] The slots 102 - a in the protruding end of the blade spars 84 - a provide a means of attaching the blade using the retaining pin 56 - a . ( FIGS. 2 , 3 and 4 ).
[0061] The blade leading edge spar 84 - a have a slight bend at the point where the blade spar 84 - a passes through the blade root base rib 88 - a , which bend is (for this demonstration), ( FIG. 5 ) shown at the five degree acute angle. The angle is shown at the leading edge of the root base rib 88 - a and the leading edge blade spar 84 - a . The blade ribs 96 and 98 are placed parallel to the blade root base rib 88 - a.
[0062] Referring to FIGS. 5 and 6 , the portion of the blade trailing edge 112 - a (root to center), which trailing edge 112 - a is arranged such that it extends from the root base rib 88 - a , to the trailing edge center 116 - a , and moves toward the blade leading edge 108 - b , which arrangement causes the blade width from the root end to its center to appear to the wind as having a uniform taper. The blade trailing edge 120 - a , which trailing edge 120 - a bends at the trailing edge center 116 - a , such that the trailing edge 120 - a is placed parallel to the blade leading edge 108 - a . This arrangement causes the airfoil blade 92 - a to bend at its center. ( FIG. 6 ) For this illustration, the acute angle of the bend is five degrees, as shown by the line drawn from C-C. The line which is drawn perpendicular to the root base rib 88 - a , line B-B, converges with the line C-C, at the blades center. The line drawn from A-A, represents the longitudinal axis of the airfoil tip blade 124 - a . The axis A-A is shown placed at an acute angle of 20 degrees to the line drawn from R-R, which line R-R represents the longitudinal axis of the spring torsion shaft 12 . The torsion shaft 12 , is placed in the plane of rotation. It should be understood that the airfoil blade 92 - a and 124 - a , shown in FIG. 6 , could be molded in one piece construction scheme, using composite materials.
[0063] This arrangement, when placed at opposite ends of the torsion shaft, as previously described, establishes a dynamic lever torsion coupling, which lever torsion coupling allows the blades to pivot, in such a way as to establish an equalization of wind velocity pressure on the blade surfaces.
[0064] The airfoil tip blade 124 - a is constructed of materials such as graphite and glass fiber. The tip blade rib 132 - a ( FIG. 5 ) is bonded to a sleeve 138 - a , which sleeve 138 - a is placed over the end of the spar 128 - a , which sleeve 138 - a can turn around the spar 128 - a . Corresponding holes are drilled through the sleeve 138 - a and the spar 128 - a , the retainer pin 136 - a is placed through the holes, such as to prevent the sleeves 138 - a from turning. The composite fiber covering of the airfoil tip blades 124 - a , and 124 - b has a resilience, which permits twisting a few degrees, without effecting the structural integrity. This arrangement permits the airfoil tip blades 124 - a and 124 - b to twist by a few degrees.
[0065] The purpose for this arrangement is to provide a simple means of adjusting the dynamic twist to the blade chord, (fine tuning).
Assembly
[0066] Ref. to FIG. 8 , for the purpose of identifying the individual parts of the lift enhancement gate valve shown in the exploded view, the number 162 represents the gate valve blade, 164 , is the gate valve blade leading edge, 166 , is the gate valve trailing edge, 167 , is one of two coupling tabs, 168 , is one of two gate valve blade hinges, 170 a is one of the two hinge pins, 170 b is one of two hinge pins, 172 , is one of two gate valve blade spring rods, 174 , is one of two gate valve blade stops, 176 a is one of two spring rod coupling links, 176 b is one of two spring rod coupling links, 178 , is one of two hinge links, 180 , is one of two hinge link posts, 182 is one of two hinge link stops, 184 is one of two hinge link post base, 186 is one of two hinge link spring rods, 188 is one of two hinge link spring rod base, 92 a is the airfoil blade, 108 a is the airfoil blade leading edge, 120 a is the airfoil blade trailing edge.
[0067] The lift enhancement gate valve shown in FIG. 9 , represents an end view of the valve at rest, where the respective chord lines (B-B) are parallel to one another, the hinge link 178 rests against the hinge link stop 182 , the gate valve blade 162 , rests against valve blade stop 174 . The line drawn from B-B represents the respective chords of the blades, the line S-S represents the longitudinal axis of hinge link spring rod 186 , and the line Y-Y (at right angle to line B-B) represents the line at which the trailing edge of gate valve blade 162 is places relative to the leading edge of the airfoil blade 92 a.
[0068] Ref. to FIGS. 8 , 9 , 10 for the purpose of illustration, ( FIG. 8 ) the width of gate valve blade 162 , can be between ten and twenty percent the width of airfoil blade 92 a . The dish shaped surface on the upwind side of gate valve blade 162 , reflects the downwind cambered surface at the nose of airfoil blade 92 a . Hinge link 178 can measure in length, a distance equal to twenty five to thirty percent the length of hinge link post 180 . Hinge link spring rod 186 ( FIG. 9 ), and hinge link post 180 , are placed such that the axis S-S is at a forty five degree angle, relative to the blade chords B-B.
[0069] In FIG. 8 , it should be understood, for the purpose of illustration only one gate valve is shown, the other valve (not shown) will have like parts and functions in a like manner.
[0070] With reference to FIG. 7 , for the purpose of illustration, the view shown would be the blade surface area seen at right angles to the wind, (the upwind side of the blades), consider the leading edge 108 a / 108 b , and the chord (B-B) the surface of the upwind side of the blades should be inclined at an acute angle to the wind. The angle would be relative to the chord (B-B) and the plane of rotation, (blade pitch angle). The blades would rotate in the direction indicated by the arrow drawn around the driveshaft 48 , (not shown).
[0071] As shown in. FIGS. 9 and 10 , the space (as seen by the wind) between the trailing edge 166 , of gate valve blade 162 , and leading edge 108 a of airfoil 92 a establishes a “flu id gate” through which air can flow. The wind velocity surface pressure acting on the upwind side of the airfoil, will be equal to the velocity surface pressure acting on the upwind side of gate valve blade 162 . The wind velocity pressure causes stress to the air particles on the upwind side of the “flu id gate” in such a way to cause a force. The force which is placed against the upwind surface of gate valve blade 162 , tends to open the gate, and cause a tension to the valve blade spring rod 172 , and hinge link spring rod 186 . The tension is progressive and causes a progressive elastic effect, (similar to the air particles escaping from a balloon) and causes the escaping air particles to increase acceleration across the down wind cambered surface of airfoil blade 92 a , which effects the rarefaction factor.
[0072] As shown in FIGS. 9 and 10 , when the relative speed of the airfoil blade 92 a increases, the relative wind velocity pressure increases at the upwind side of the “flu id gate”, and the stress placed on the air particles at the upwind side of the “fluid gate”, will essentially place a progressive force (tension) against the valve blade spring rods 172 , via the upwind surface of gate valve blade 162 . The force causes the gate valve blade 162 , to swing on valve blade hinges 168 , and hinge pins 170 a , and causes hinge links 178 to swing on hinge pins 170 b at hinge link posts 180 , in such a way as to cause spring rods 186 to bend, via the spring rod coupling links 176 b . This causes hinge link 178 to swing on hinge pin 170 b , such that the trailing edge 166 of gate valve blade 162 tends to move in an arc toward the surface of airfoil blade 92 a , which movement tends to close the “fluid gate”, however, as the relative wind velocity pressure progressively increases at the upwind side of the “fluid gate”, it causes a progressive wind velocity pressure on the upwind surface of gate valve 162 . The pressure tends to open the “fluid gate”, and causes the valve blade spring rods 172 and hinge link spring rods 186 to bend in such a way as to cause a progressive tension to the air particles. The progressive tension causes the escaping air particles to accelerate. The arrangement causes a progressive accelerated boundary flow of air across the downwind cambered surface of airfoil blade 92 a , and directs the escaping accelerated air particles to strike the surface of the downwind side of the blade 92 - a at the appropriate ‘angle of incidence’ such as to ca use the optimal dynamic lift enhancement.
[0073] When the wind velocity pressure acting on the upwind side of gate valve blade 162 ( FIG. 10 ) reaches a certain force the leading edge 164 of gate valve blade 162 moves toward the trailing edge 120 a of airfoil blade 92 a , and will essentially aligns both chord lines B-B ( FIGS. 9 & 10 ) with one another and the chord of gate valve blade 162 ( FIG. 10 ) is aligned with the boundary flow, such that the dynamic drag to gate valve blade 162 will be minimal (lift to drag ratio).
[0074] It should be understood that the torsion pivot blades can function by using a one piece spring or rigid torsion shaft, which torsion shaft would journal perpendicular through a driveshaft, would be free to pivot, and the blades would be affixed to opposite ends of the torsion shaft, such that the blade chords would be in an offset relationship to one another, (a fixed blade pitch angle) and to have a means to couple and uncouple the blades from one another;
[0075] This arrangement would function well for smaller wind electric battery chargers, but the variable pitch blades (w/lift enhancement gate value), provide other applications, such as large electric wind generators and hovercraft.
[0076] While various examples and embodiments of the present invention have been shown and described, it should be appreciated by those skilled in the art that the spirit and scope of the present invention are not limited to the specific description and drawings herein, but extend to various modifications and changes. | A pair of airfoil blades having a longitudinal axis coincident with one another. Each blade is bent at the center on the plane of the chord. Each blade has an airfoil tip blade placed at the outer most trailing edge. The blades are affixed by their root ends to opposite ends of a torsion shaft. The blade chords are offset from one another, which defines a blade pitch angle. The torsion shaft is journaled perpendicular through a driveshaft, whereas the rotation of the blades can transfer through the torsion shaft to the driveshaft and cause the driveshaft to turn, eliminating the need for a hub. The blades are adapted to pivot along with the torsion shaft. The blades lie in substantially the same plane, and are adapted for rotation in a plane orthogonal to the longitudinal axis of the driveshaft. Each blade has an airfoil shaped fluid gate valve disposed on the leading edge. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a well tool assembly in subterranean oil and gas wells and, more specifically, to a seal assembly for use in the bore of a well tool such as a packer.
2. Description of the Prior Art
Downhole oil tools, such as packers, employed in oil and gas wells are commonly used with seal assemblies in tubing seal receptacles which can be attached to the tubing string which extends to the top of the well. In these conventional tubing seal receptacles, a seal stack, normally comprising an axial array of individual annular seals having a generally V-shaped cross-sectional configuration, is employed to establish sealing integrity between the tubular seal receptacle and the honed surface of the bore of a downhole tool. It is common practice to insert or stab-in a seal assembly on a tubing seal receptacle into the bore of a downhole tool such as a packer which has previously been anchored in position in the well bore. Under conventional environmental conditions within a well bore, these V-shaped seals can be fabricated from conventional elastomeric sealing materials such as nitrile rubber. Although problems can be encountered with inserting or stabbing such conventional seals into a packer bore, an exceptable degree of success has been achieved in establishing sealing integrity with the bore of a packer using these conventional seal assemblies.
Despite the reliability of conventional seal assemblies under normal well conditions, these conventional seals do not establish satisfactory sealing integrity under hostile conditions, such as high temperatures and in the presence of a corrosive chemical environment or other hostile conditions which may be encountered at a subsurface location in a well bore. High-performance sealing elements composed of materials which can withstand these hostile environmental conditions have been utilized. For example, certain elastomeric materials such as ethylene-propylene terpolymer elements, propylene tetrafluoroethylene, perfluoroelastomer, fluorelastomer elements and polytetrofluoroethylene elements perform satisfactorily under hostile conditions.
Despite the excellent sealing properties exhibited by these elastomeric materials under hostile environmental conditions, much difficulty has been encountered in actually inserting seals formed using these elements into the cylindrical bore of a downhole well tool. It has been found that seals formed from these compositions can encounter severe stab-in damage, sometimes resulting in the destruction of the annular seal elements, when seals mounted on a tubing seal receptacle are inserted into the bore of a well packer. It has been speculated that one source of these problems is the expansion or swell of these high-performance sealing elements as the tubing seal receptacle is lowered from the surface to the location of the well tool anchored in the well. For example, excessive thermal expansion can occur in certain elements. Other elements can exhibit significant swell or expansion when exposed to fluids which may be present within a well. For example, in certain wells using petroleum-based drilling fluids, the volume of the high performance sealing elements increases substantially.
SUMMARY OF THE INVENTION
This invention relates to a tubing seal assembly which is adapted to be carried on a tubing string and stabbed into the bore of the well packer or similar well tool anchored in a subterranean oil or gas well to establish fluid communication through the tubing string and the packer or other well tool. An anchor seal assembly, which can comprise a latching member for mechanically engaging the well tool or packer, includes annular sealing elements disposed circumferentially around the tubing seal assembly. These seals must be snugly inserted into the seal bore of the well packer.
These seals are positioned within a cavity on the exterior of the tubular seal receptacle. A cylindrical sleeve surrounds the tubular member and constrains the seals as the seals are inserted into the well prior to engagement of the anchor latch on the well tool bore. The cavity defined on the exterior of the tubular member and covered by the cylindrical sleeve has a volume which is at least equal to the unconstrained volume of the seals under the ambient conditions existing at the surface of the well. The volume of the cavity is, however, less than the unconstrained volume of the seals under the conditions existing at the subsurface location at which the well tool or packer is located.
The cylindrical sleeve is shearably attached to the tubing seal receptacle, but can be shifted axially as the seals are inserted into the bore of the well packer. Thus the seals are maintained in a constrained position by the sleeve during insertion in the well until the time when the seals are inserted or stabbed into the tool seal bore. The seals are, of course, maintained in a constrained configuration after insertion into the seal bore of the packer. Therefore, any swell or expansion of the seals is limited to the volume of the cavity defined on the interior of the packer, and problems heretofore encountered during insertion or stab-in of the seals into the packer seal bore are avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1B, 1C, 1D and 1E collectively constitute a quarter-sectional view of the tubing seal assembly above the point of initial engagement with the upper end of the seal bore of a well packer located in a well.
FIGS. 2A, 2B, 2C, 2D and 2E are views similar to FIGS. 1A, 1B, 1C, 1D and 1E, but showing the seal assembly fully inserted into the packer seal bore.
FIG. 3 is a sectional view of the geometric configuration of a seal assembly which can employ high-performance sealing elements subject to swell or expansion under hostile environmental conditions in a well.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Well packers, such as the packer P are commonly used at subsurface locations to provide sealing integrity between a tubing string inserted within a well casing and the bore of a downhole tool. The packer thus establishes a seal in the annulus between the tubing and the casing. The annular area above the packer is thus isolated from the annular area below the packer. Packers are employed for a number of different downhole operations and can be either permanently anchored within the well or can be of the retrievable type.
The packer P shown in the drawings (FIG. 1E) is of the type generally employed as a permanent packer within a well. Packers such as packer P normally consist of two principal elements. First is an annular packing element, such as packing element 30, which is adapted to radially expand upon the application of an axially compressive force. Conventional packers also employ anchoring means such as radially expandable slips to anchor the packer and the packing element 30 in the well. The packer P employs upper and lower anchoring slips 24 and 38 which are radially expandable to secure the packer within the well casing 1. A number of conventional means are employed to set a packer within a well. For example, packers may be set by tubing manipulation, by the action of hydraulic pressure, or by manipulation of the components of the packer by a wireline string extending to the surface of the well and attached to wireline tools for engaging and setting the packer.
During the operation of a downhole tool such as a packer P, it is necessary under certain circumstances to insert a tubing string into the well and establish communication with a bore of a packer anchored at a subsurface location. The conventional manner of establishing such communication is to establish sealing integrity with the bore of the packer or with an extension thereof. Thus, sealing elements are commonly provided on the exterior of the tubing inserted into the bore of the packer. These seals engage a seal bore surface in the bore of the packer or in a seal bore extension of the packer. FIGS. 1A, 1B, 1C, 1D and 1E show the packer P, a seal-bore extension 14 extending upwardly therefrom, and a sealing element 10 of the type employed in the preferred embodiment of this invention. It should be understood, however, that these Figures do not depict the seal system or the packer P in their interengaged configuration as used in the well and, these Figures are merely intended to illustrate separate positions of both the sealing assembly and the Packer P, prior to establishing the aforementioned sealing integrity.
As shown in FIG. 1A, a portion of the tubing string, consisting of tubing T, is attached to a tubular member 2 by threads 2a. A tubular sleeve 4 is connected to the exterior of tubular member 2 by means of conventional threads 4b and a set screw 4a. An outer seal constraining sleeve 6 extends below the upper tubular sleeve 4 and partially overlaps a portion of the tubular sleeve 4 (FIG. 1B) along the upper portion of the inner bore 6a of the outer constraining sleeve 6. The upper portion of the constraining sleeve 6 has inner diameter slightly in excess of the outer diameter of the tubular sleeve 4. No sealing integrity is established along the portion of the inner surface 6a of the upper constraining sleeve portion which overlaps the tubular sleeve 4. An annular cavity 8, however, is defined around the tubular sleeve 4. A suitable fluid may be deposited within cavity 8 during assembly of the sealing assembly. The purpose of the fluid contained within cavity 8 will be apparent subsequently.
The constraining sleeve 6 is attached to the tubular member 2 by means of one or more threaded shear pins 6d located below cavity 8. A conventional O-ring seal 6b is disposed along the inner bore of carrier sleeve 6 below the cavity 8 and above the pin 6d. A suitable vent hole 6c is located immediately below the seal 6b, but O-ring seal 6b establishes sealing integrity between the tubular member 2 and the constraining sleeve 6 below the cavity 8. Thus, the cavity 8 is open at its upper end to the exterior along surface 6a, but sealing integrity is established below the cavity 8 by the O-ring seal 6b.
Tubular member 2 is attached at its lower end to a seal carrier sleeve or mandrel 12, by threads 2b. A seal assembly 10, which will be described in detail with reference to FIG. 3, is located between the seal carrier section 12 and the tubular member 2. The seal assembly 10 is retained within an annular cavity between the carrier 12 and the lower portion 6e of constraining sleeve 6. The cavity within which the seal assembly 10 is retained has a volume which is less than the volume of the seal assembly 10 under the conditions which will exist at a downhole location in which the packer P is located. A detailed discussion of this relationship will be presented with reference to FIG. 3.
The lower portion of seal carrier 12 abuts a springloaded latching collet 16 (FIG. 1C) having latching threads 16a at its lower end. The latching element 16a is of the conventional type adapted to engage similar threads in a packer or a seal bore extension thereof.
As shown in FIG. 1D, the upper seal bore extension 14 of the packer P comprises a tubular member having internal threads 14a located intermediate its ends. Threads 14a are the type adapted to engage with the threads 16a located on the latching collet 16 affixed to receptacle extension 18.
An upwardly facing inclined shoulder 14b is provided at the lower end of the upper portion of the seal bore receptacle 14 and comprises the section of the packer intermediate the upper seal bore receptacle and the main body 15 of the packer. A metal sealing ring 20 is attached at the lower end of the tubular seal receptacle extension 18 which is attached to the bottom end of seal carrier 12 by threads 12a. This metal sealing ring 20 can be fabricated from a soft metal, and as can be seen in FIG. 1, is opposed to the upwardly facing shoulder 14b at the upper end of the body 15.
As stated, the conventional packer P shown in FIGS. 1D and 1E comprises a permanent-type packer. An upper gage ring 22 is secured to body 15 of the packer by a pin 14c. Radially expanding slips 24 of the conventional type are located below the gage ring 22. Although not shown in detail in FIG. 1D, a conventional locking arrangement, such as a body lock 23 which engages external threads on the body 15 of the packer and internal threads on gage ring 22, is located above the slips 24. A slip expander cone 26 is located immediately below slips 24 and has an upwardly facing inclined surface 26a to radially expand the anchoring slips 24 upon axial contraction of components of the packing element. Immediately below the expander cone 26 is a radially expandable extrusion ring 28 of the conventional type. A packing element assembly 30 is located between upper and lower extrusion rings 28 and 32, which can be of the conventional type.
A lower expander cone 36 is secured to the packer body 15 by a shear pin 34. Lower slips 38 suitable for anchoring the packer against downwardly directed forces are located in engagement with the inclined surface of cone 36.
A lower gage ring 40 is located below slips 38 and is secured to the body 15 of the packer by threads 15a. A pin 42 extends through the gage ring 40 to further secure the lower gage ring in position. If additional segments of the tubing string are to be attached below the packer P, a crossover coupling 44 can be located therebelow for attachment of the lower portions of the tubing string or a tailpipe. The packer P shown herein corresponds in general to a conventional packer such as the Baker Model DA Retainer Production Packer or the Baker Model HEA Retainer Production Packer.
FIG. 2A, 2B, 2C, 2D and 2E show the configuration of the packer and seal receptacle assembly when the packing element 30 and the slips 24 and 38 are radially expanded into engagement with the casing bore 1a and the seals 10 stabbed into the seal receptacle 14 of the packer. Additionally, a seal has been established by the engagement of the metal seal ring 20 with the upwardly facing shoulder 14b at the juncture between the seal bore extension 14 and the main body 15 of the packer P. Thus, redundant sealing integrity is established both by the metal seal ring 20 and by the seal assembly 10, preventing any leakage from the bore of the packer P to the annulus above the packer.
When the packing elements 30 and the anchoring slips 24 and 38 are expanded to secure the packer P in place, the seal assembly 10 can be stabbed-in into the packer seal bore extension 14. As the seal assembly 10 is first inserted into the seal bore extension 14, the seal assembly 10 will occupy the position shown in FIG. 1B. FIG. 1D shows that the metal seal ring 20 has not been inserted into engagement with the upwardly facing shoulder 14b, in other words, the seal assembly has not been inserted or "stabbed in" into the packer bore. Note also that sleeve 6 is in its downward position with shear pin 6d intact. In this position, the seal assembly 10 is completely retained within the cavity formed by the constraining sleeve 6, the end of tubular member 2 and the seal carrier 12. In the position shown in FIG. 1C, the lower end surface 6f of the constraining sleeve 6 has come into engagement with the upper end surface 14f of the seal receptacle 14. Continued downward force applied to the tubing string will then result in relative movement between the tubular member 2 and the constraining sleeve 6. Upon the application of sufficient downwardly directed force, shear pin 6d is severed and the tubular member 2 and extension 18 continue to move downwardly relative to constraining sleeve 6. More importantly, the seal stack 10 also continues to move downwardly relative to the carrier sleeve and is ultimately inserted or "stabbed-in" into the seal receptacle 14 to establish engagement and sealing integrity with the inner surface 14d of the seal receptacle 14. Additionally, the threads 16a of collet 16 will engage threads 14 a on seal bore extension 14.
The inner portion of the seal assembly 10 ultimately is inserted into the seal receptacle 14 to a degree sufficient to allow sealing engagement between the metal sealing ring 20 and the upwardly facing shoulder 14b, as shown in FIG. 2D.
The liquid located in cavity 8 serves to dampen movement of the telescoping inner mandrel assembly 2 and 12 relative to the constraining sleeve 6. Since there is no sealing engagement along surface 6a, the liquid located in cavity 8 can be forced outwardly through the upper end of the cavity, thus creating a dampening effect which can prevent damage to the seal assembly 10 and to the metal seal ring 20, which might be caused by rapid engagement of either with the inner surface of the seal receptacle 14.
The operation of the constraining sleeve 6 to prevent damage to the seal stack 10 can be understood more completely with reference to FIG. 3. The configuration of the seal stack 10 shown in FIG. 3 is generally conventional and comprises a plurality of upwardly and downwardly facing annular seal units. Each separate seal unit comprises a metal backup or spacer 101 in engagement with a first polymeric backup ring 102. Note that the engagement between the metal ring 101 and the polymeric backup member 102 is along a convex-concave mating surface. In the preferred embodiment of this invention the polymeric element 102 can comprise an annular member formed of a material such as that sold under the trademark Ryton, a trademark of Phillips Petroleum. A second backup member 103 is located in engagement with the backup 102. In the preferred embodiment of this invention, the secondary backup can comprise a member formed of polytetrofluoroethylene, commonly referred to under the trademark Teflon, a trademark of DuPont. The primary sealing element 104 comprises an annular member having a cheveron cross-section. Each seal unit is further comprised of a second polymeric backup member 105 in engagement with the opposite end of the primary sealing element 104. This second backup element 105 can also comprise an element formed of a material such as Ryton.
The primary sealing element 104 can be fabricated from a plurality of different types of materials. For example, these sealing elements can be formed of material such propylene tetrafluoroethylene. The primary sealing element also can be formed of a perfluoroelastomer, such as Kalrez, a trademark of DuPont. Another material which also exhibits excellent sealing characteristics comprises fluoroelastomer. This invention can also be employed with other more conventional sealing elements, such as polytetrofluoroethylene elements or polybutadiene-coacrylonitrile elements, if anticipated swell in downhole conditions requires use of this configuration. Such swell can arise from a number of factors. For example, some elements undergo a volumetric expansion when placed in certain oil-based materials. Furthermore, elevated temperatures at downhole locations can also result in thermal expansion of the seal elements.
A number of the seal elements which exhibit good sealing characteristics also exhibit swell or volumetric expansion, which had been found to be a problem when the sealing stack is to be inserted or stabbed into the bore of a seal receptacle. In this invention, the seal stack 10 is always confined to a cavity 11 having a volume which is less than the volume that the seal unit would occupy when subjected to downhole conditions, if it were unconstrained. As the seal stack is inserted into the well, this cavity 11 is defined by the tubular member 2, the seal carrier 12, and the constraining sleeve 6. When inserted into the seal bore receptacle 14, this cavity is defined by the end of tubular member 2, the seal carrier 12, and the seal bore 14d of the packer P; the carrier sleeve 6 having been moved upwardly relative to the seal stack 10. This prevents the seal stack from being damaged or destroyed when stabbed-in or inserted into the seal bore receptacle 14.
As can be seen from FIG. 3, the multicomponent seal stack can easily be damaged if it is forcibly inserted into the seal receptacle 10 after swelling. As the lower seal elements are inserted into the bore, if they can be inserted therein, the friction due to the close engagement of the primary sealing elements with the inner bore 14d of the seal receptacle 14 exerts an upwardly directed force on the other sealing elements. If these upper sealing elements have expanded significantly beyond their volume when the seal assembly is originally assembled, they cannot be inserted into the bore of the packer and will be swabbed off or stripped from the seal assembly. Such damage has often occured when high-performance seal stacks are to be used and represents a continuing problem, which has now been solved in a reliable and economic manner.
Although the invention has been described in terms of specified embodiments which as set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of this disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | A method and apparatus for inserting a seal stack in a seal bore defined by a well tool located downhole where ambient conditions would cause radial swelling of the seal stack. The seal stack is mounted at the surface in a confined space defined between a mandrel and a constraining sleeve shearably connected to the mandrel. Upon run-in of the mandrel to enter the seal bore, the constraining sleeve engages an upwardly facing surface surrounding the entrance to the seal bore which prevents further downward movement of the constraining sleeve. Application of a downward force effects the shearing of the connection between the mandrel and the constraining sleeve and permits the mandrel and seal stack to be inserted in the seal bore while the constraining sleeve moves upwardly relative to the mandrel. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to apparatus for the continuous pressing and decatizing of cloth, woven and knitted fabrics, and like material.
2. Description of the Prior Art
German Pat. No. DAS 2,456,921 discloses a system for decatizing fabric comprising a rotatably mounted heatable cylinder, an inner back cloth which, prior to passing around the heatable cylinder is led over a steaming section, and an outer runner cloth which presses the back cloth towards the cylinder. The fabric to be treated is passed between the cylinder and the inner back cloth, and the outer runner cloth is constructed as a pressure belt and is under high tensile stress.
This prior art system is advantageous over previously known cylinder presses in that the pressing treatment occurs without stretching giving rise to a considerably improved sewability. The endless back cloth is, for example, made of satin and circulates without slipping with the pressure belt. The back cloth serves two purposes; on the one hand, the very smooth and even surface of the satin back cloth prevents the relatively coarse surface of the pressure belt from being impressed on the surface of the fabric being treated, and on the other hand, the back cloth serves the purpose of expansionless conveying of the fabric through the steaming section and around the cylinder.
However, the insertion of the back cloth between the fabric and the pressure belt raises a number of problems which may only be overcome with difficulty. For example, quite appreciable wear of the back cloth occurs due to the continuous alternation between the steaming action and the intensive pressing action under high specific contact pressure and at temperatures of between 100° C. and 160° C. The additional costs incurred as a consequence of this wear renders the profitability of the whole process doubtful. These additional costs are made up by the replacement cost of the endless back cloth and the costs of changing this endless back cloth, the latter costs being fairly high inasmuch as the guide and tensioning rollers around which the back cloth passes are comparatively heavy rollers and must be disassembled to replace the worn back cloth. Production is obviously stopped during this period, so that further costs are incurred due to loss of production.
Another disadvantage of the back cloth is that the finish on the fabric being treated differs very greatly between a new and a worn back cloth, so that a change in the quality of fabric finish can be observed over the life of a back cloth. Furthermore, the back cloth prevents direct thermal contact between the pressure belt and the fabric and since the back cloth has an insulating action this reduces the fabric temperature which can be achieved.
It is consequently an object of the invention to provide improved apparatus for pressing and decatising fabric. It is a further object of the invention to provide apparatus in which the endless back cloth may be omitted without giving rise to unacceptable stretching of the fabric being treated.
SUMMARY OF THE INVENTION
According to the invention, there is provided in an apparatus for the continuous pressing and decatizing of cloth and fabric material, an arrangement comprising a rotatably mounted, heatable cylinder, first heating means arranged to heat said cylinder, a pressure belt arranged to directly contact material undergoing treatment to press said material around the cylinder, rollers for circulating the pressure belt, and second heating means arranged to heat the pressure belt prior to passage around the heatable cylinder, said heating means being independently controllable whereby to set up a temperature differential across the material as it is pressed between the cylinder and pressure belt.
By setting up a temperature differential across the fabric as it is taken between the cylinder and pressure belt, condensation can be preferentially induced towards one side of the fabric and this damper side of the fabric is found to have reduced surface luster.
BRIEF DESCRIPTION OF THE DRAWINGS
Apparatus embodying the invention and for pressing and decatizing cloth and fabric, will now be particularly described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a part sectional view of the apparatus including a first form of humidifying device;
FIGS. 2 and 2a are vertical cross-sections through second and third forms respectively of humidifying device for use with the apparatus;
FIG. 3 is a section through part of a heatable cylinder of the apparatus showing a fabric under treatment being pressed against the cylinder by a pressure belt, the surface temperature of the cylinder being greater than that of the pressure belt; and
FIG. 4 is a section similar to FIG. 3 for the condition wherein the surface temperature of the heatable cylinder is lower than that of the pressure belt.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a fabric 1 undergoing treatment is pressed directly against the surface of a heatable cylinder 3 by means of a pressure belt 2. The surface of the cylinder 3 is highly polished and unscored.
The pressure belt 2 comprises a high-strength carrier element with a coating on both sides having a particularly homogenous, smooth and heatproof surface. The thickness of the coating is substantially greater on the fabric side of the belt.
The pressure belt 2 is passed around rollers 4,5 and 6, the roller 4 serving as a driving roller and the roller 6 serving as a tensioning roller for the pressure belt 2. The roller 5 is heated and serves as a heating roller for heating the pressure belt 2 to a desired temperature for passage around the cylinder 3.
The rollers 5 and 6 and the heatable cylinder 3 are allowed to revolve freely about their axes. A belt control roller 7 is provided to align the pressure belt 2 and ensure that it always circulates centrally.
Prior to undergoing pressing around the cylinder 3, the fabric 1 is subjected to a moisturizing operation on a carrying belt 8, below which are situated several steam chests 9, 9a which in the form of moisturizing device shown in FIG. 1 blow steam out upwards.
A suction hood 10 is situated above the carrying belt 8 and communicates with a fan which draws off the steam vapours released.
A feed roller 15 conveys the fabric 1 to the carrying belt 8. The belt 8 is driven by a drive roller 14 which revolves at an automatically controlled peripheral speed V 1 . Control of the rotational speed of the roller 14 is effected using a non-contact sensor incorporating a photocell or an air reflex nozzle 13 arranged to sense the position of a loop of the fabric 1.
FIGS. 2 and 2a show modified forms of the moisturizing device.
In the form of device shown in FIG. 2, the fabric is taken by the carrying belt 8 around a loop lying within a steaming chamber 11. Steam is supplied to the inside of the loop through perforations provided on both sides of a steaming chest 12. The air nozzle 13 monitors the position of the bottom of the fabric loop to control automatic re-adjustment of the peripheral speed of the take-off roller 14 with respect to the feed roller 15.
In the form of the moisturizing device shown in FIG. 2a the fabric is taken by the belt 8 around a steaming cylinder 16 which also serves to convey the fabric. The steaming cylinder 16 thus performs the task of the roller 14 shown in FIGS. 1 and 2 and feeds the fabric forward at a speed V 1 .
Using the described forms of moisturizing device the fabric 1 can be conveyed through the moisturizing device to be moistened without being stretched (indeed, some shrinkage may occur).
Returning to FIG. 1, the moisturizing device is followed by a feed roller 18 driven at a peripheral speed V 2 . The speed of the roller 18 is controlled automatically by a system arranged to control a variable speed transmission of the roller 18 in dependence on signals received from a non-contact fabric sensor 17 positioned immediately downstream of the roller 14 (or, for the FIG. 2a device, downstream of the cylinder 16).
The pressure belt drive roller 4 revolves at a peripheral speed v 3 and determines the speed of the pressure belt 2 as well as the actual speed of traversal of the fabric 1 through the pressing means formed by the cylinder 3 and pressure belt 2.
After the fabric 1 has left the pressing means, it is moved by a controllably driven fabric take-off roller 20 over a freely rotatable guide roller 19 and fed to cuttling machine 21. A sensor 22 monitors the fabric 1 to effect automatic re-adjustment of the peripheral speed v 4 of the fabric take-off roller 20.
The temperature of the roller 5 is controllable independently of the temperature of the cylinder 3 to enable the surface temperature of the pressure belt 2 to be set as desired relative to the surface temperature of the heatable cylinder 3.
The cylinder 3 and the roller 5 are heated by respective steam heating means, the steam (or other suitable heat carrier) being supplied to these heating means at rates controlled by respective steam volume governors 27 and 27a. The governors 27 and 27a are in turn controlled by respective temperature regulators 26 and 26a which are connected via amplifiers 25 and 25a to respective temperature sensors 24 and 23. The sensor 24 is arranged to measure the surface temperature of the cylinder 3 whereas the sensor 23 is arranged to measure the surface temperature of the belt 2 adjacent the cylinder 3.
In operation of the apparatus, the fabric is conveyed through the moisturizing device by the carrying belt 8 and is then taken around the cylinder 3 by the moving belt 2 which serves to directly press the fabric 1 against the surface of the cylinder 3.
Under the pressure and temperature experienced by the fabric between the cylinder 3 and belt 2, moisture introduced into the fabric 1 in the moisturizing device is vapourised giving rise to a press steaming and shrinking caused by the application of a high contact pressure over a relatively great area of the fabric. The feel of fabric treated in this manner is comparable to the results of a conventional span or profile pressing plant. The great advantage of the present apparatus is that this result may now be obtained in a continuous operation.
By suitable setting of the temperatures of the cylinder 3 and the roller 2, a temperature difference can be set up across the fabric 1 as it is taken around the cylinder 3 by the belt 2.
If, for example, the surface temperature of the cylinder 3 is selected to be 140° C. and higher than the surface temperature of the pressure belt 2, (at, for example, 90°-95° C.) condensation will preferentially occur on the side of the fabric 1 towards the pressure belt 2 under the specific contact pressure during the vapourisation of the moisture introduced into the fabric (see FIG. 3). The amount of moisture at the left-hand side of the fabric (underside) results in a lesser glazing action as compared to the right-hand side of the fabric which is pressed against the hotter cylinder 3. If, on the other hand, the surface temperature of the pressure belt is raised to 130° C. or 140° C. and the temperature of the cylinder is lowered to approximately 85 to 100° C., a reversed effect results (see FIG. 4).
The action of luster reduction under full pressing effect is useful in practice since higher contact pressures may be applied during pressing, without stretching or the so-called "greasy luster" becoming excessive. (It will be recalled that higher pressing thrusts tend to smooth and compact the fibrous structure of the fabric). The greater proportion of the press shine produced is transient and disappears during finish pressing.
In the prior art cylinder press system, the magnitude of the pressure which could be applied was not only limited by the need to avoid excessive luster but also by the fact that slip creases occurred suddenly in the fabric due to relative displacement between the stationary shell and the revolving press cylinder. | In an apparatus for the continuous pressing and decatizing of fabric, a pressure belt serves to move a fabric undergoing treatment around a rotatably-mounted and heatable cylinder. The pressure belt directly contacts the fabric to press it against the cylinder. The surface of the pressure belt is arranged to be heated by a heating roller around which the belt passes prior to passage around the cylinder. The cylinder and heating roller can be independently heated to different temperatures to produce a temperature differential across the fabric as it is pressed. As a result, moisture condensation preferentially occurs on one side of the fabric causing luster reduction on that side of the fabric. | 3 |
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