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TECHNICAL FIELD
[0001] Embodiments are generally related to door latch assemblies, including door latching mechanisms utilized in automobiles and other vehicles. Embodiments are also related to geartooth sensor devices and techniques thereof.
BACKGROUND OF THE INVENTION
[0002] Latching mechanisms are utilized in a variety of commercial and industrial applications, such as automobiles, airplanes, trucks, and the like. For example, an automotive closure, such as a door for an automobile passenger compartment, is typically hinged to swing between open and closed positions and conventionally includes a door latch that is housed between inner and outer panels of the door. The door latch functions in a well-known manner to latch the door when it is closed and to lock the door in the closed position or to unlock and unlatch the door so that the door can be opened manually.
[0003] The door latch can be operated remotely from inside the passenger compartment by two distinct operators—a sill button or electric switch that controls the locking function and a handle that controls the latching function. The door latch is also operated remotely from the exterior of the automobile by a handle or push button that controls the latching function. A second distinct exterior operator, such as a key lock cylinder, may also be provided to control the locking function, particularly in the case of a front vehicle door. Each operator is accessible outside the door structure and extends into the door structure where it is operatively connected to the door latch mechanism by a cable actuator assembly or linkage system located inside the door structure.
[0004] Vehicles, such as passenger cars, are therefore commonly equipped with individual door latch assemblies which secure respective passenger and driver side doors to the vehicle. Each door latch assembly is typically provided with manual release mechanisms or lever for unlatching the door latch from the inside and outside of the vehicle, e.g. respective inner and outer door handles. In addition, many vehicles also include an electrically controlled actuator for remotely locking and unlocking the door latches.
[0005] One of the problems inherent with conventional latching mechanisms is that it is difficult, but necessary, to control motors, including gears thereof, within vehicle latch assemblies. In particular, it is desirable to enable all required functions of a vehicle latch assembly utilizing only a single motor, because of the efficiencies that can result from such a configuration. Current solutions employ a complex ring magnet, together with a sensor that acts upon a gear with multiple revolutions. A need thus exists for a method and system which overcomes and simplifies the need for multiple gear revolutions, including the current complex ring magnet.
BRIEF SUMMARY OF THE INVENTION
[0006] The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0007] It is, therefore, one aspect of the present invention to provide for an improved latch mechanism.
[0008] It is another aspect of the present invention to provide for improved latching methods and systems for use in automobiles and other vehicles.
[0009] It is yet a further aspect of the present invention to provide for a geartooth sensor that provides data for the control of a vehicle door latch assembly.
[0010] The aforementioned aspects of the invention and other objectives and advantages can now be achieved as described herein. A latch assembly control method and system are disclosed herein, wherein a latch assembly is integrated with a motor having at least one gear thereof for actuating a plurality of components of the latch assembly. A geartooth sensor can be associated with the latch assembly, wherein the geartooth sensor senses a position of one or more gears, wherein the gear completes less than one revolution to thereby provide a known reference point registration and calibration of the latch assembly via data collected from the geartooth sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0012] FIG. 1 illustrates a perspective view of a vehicle door mounted to a passenger vehicle in which a preferred embodiment of the present invention can be implemented;
[0013] FIG. 2 illustrates a perspective view a sensor associated with a gear having a plurality of teeth, which may be adapted for use in accordance with an embodiment of the present invention;
[0014] FIG. 3 illustrates a top view of a sensor with a rotatable member having a plurality of teeth, which may be adapted for use in accordance with an embodiment of the present invention;
[0015] FIG. 4 illustrates a side view of the configuration depicted in FIG. 3 ;
[0016] FIG. 5 illustrates a time-based waveform representative of the algebraic sum of signals provided by the sensor depicted in FIGS. 2-4 ;
[0017] FIG. 6 illustrates a time-based fourth output signal provided by comparing the magnitude of the waveform in FIG. 5 to a reference value; and
[0018] FIG. 7 illustrates a high-level block diagram of a system, which can be implemented in accordance with a preferred embodiment of the present invention; and
[0019] FIG. 8 illustrates a high-level block diagram of a system, which can be implemented in accordance with an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment of the present invention and are not intended to limit the scope of the invention.
[0021] FIG. 1 illustrates a perspective view of a vehicle door 13 mounted to a passenger vehicle in which a preferred embodiment of the present invention can be implemented. A vehicle, such as an automobile can be equipped with one or more individual door latch assemblies 11 , which secure respective passenger and driver side doors to the vehicle 15 . Each door latch assembly 11 is typically provided with manual release mechanisms or lever for unlatching the door latch from the inside and outside of the vehicle, e.g. respective inner and outer door handles. In addition, many vehicles can also be equipped with electrically controlled actuators for remotely locking and unlocking the door latches. As indicated in FIG. 1 , a door latch assembly 11 can be mounted to a driver's side vehicle door 13 of a passenger vehicle 15 . The door latch assembly 11 may be mounted to front and rear passenger side doors thereof and may be incorporated into a sliding side door, rear door, a rear hatch or a lift gate thereof, depending upon design constraints.
[0022] FIG. 2 illustrates a perspective view of a sensor 10 associated with a rotatable member, such as a gear, which has a plurality of discontinuities, such as teeth, formed in its peripheral surface. Sensor 10 can be adapted for use in accordance with an embodiment of the present invention. Sensor 10 is not considered a limiting feature of the present invention but is describe herein for general illustrative and edification purposes only. It can be appreciated that other types of sensors can be implemented in place of sensor 10 .
[0023] In general, sensor 10 comprises a first magnetically sensitive device 12 and a second magnetically sensitive device 14 . In a preferred embodiment of the present invention, the first and second magnetically sensitive devices can be Hall-effect transducers. In FIG. 2 , the first and second magnetically sensitive devices are disposed on a ceramic substrate 16 , which can also support an electronic circuit to amplify first and second output signals that are provided by the first and second magnetically sensitive devices, respectively. In addition, certain embodiments of the present invention can also combine the first and second output signals and compare the combined signal to a reference magnitude.
[0024] With continued reference to FIG. 2 , a magnet 20 can provide a means for disposing the first magnetically sensitive device 12 in a magnetic field of a first direction and for disposing the second magnetically sensitive device 14 in a magnetic field of a second direction. As shown in FIG. 2 , the U-shaped magnet 20 generally provides such a disposing means because its south pole is proximate the first magnetically sensitive device 12 and its north pole is proximate the second magnetically sensitive device 14 .
[0025] The sensor 10 can be disposed proximate a rotatable member 24 which has at least one discontinuity in its surface. If the rotatable member 24 is a gear, as shown in FIG. 2 , a plurality of teeth 26 extend from the outer periphery of the rotatable member 24 . Between each tooth is a space 28 . The sensor 10 can be disposed proximate the rotatable member 24 in such a manner that its first and second magnetically sensitive devices are simultaneously located proximate different regions of its outer periphery. In other words, when the first magnetically sensitive device 12 is proximate a tooth 26 , the second magnetically sensitive device 14 is proximate a space 28 . To achieve this result, the axis of the sensor 10 can be disposed at an angle relative to the axis of the rotatable member 24 . Rotatable member 24 can be implemented, for example, as a gear having a plurality of teeth 26 integrated therewith.
[0026] FIGS. 3 and 4 illustrate the relative position of the sensor 10 and the rotatable member 24 . In FIG. 3 , the outer surface 30 at the distal end of each tooth is identified and the bottom surface of each space 28 is identified. As can be seen in FIG. 3 , the first magnetically sensitive device 12 is disposed proximate an upper tooth surface 30 while the second magnetically sensitive device 14 is disposed proximate a space 28 . As the rotatable member 24 rotates about its central axis 34 , each of the two magnetically sensitive devices will sequentially experience both teeth and interstitial spaces. However, the spacing between the first and second magnetically sensitive devices, the spacing between the teeth of the rotatable member and the relative angle between the sensor 10 and the angle of rotation 34 assure that the first and second magnetically sensitive devices are always disposed proximate different regions of the rotatable member 24 .
[0027] FIG. 4 illustrates a side view of the configuration depicted in FIG. 3 . As the rotatable member 24 rotates about its central axis 34 , as indicated by arrow A, the first and second magnetically sensitive devices are sequentially disposed proximate the discontinuities, or teeth, of the rotatable member. The first magnetically sensitive device 12 has an output signal which is representative of the magnitude and direction of the magnetic field in which is disposed. Similarly, the second magnetically sensitive device 14 also has an output signal which is representative of the strength and direction of the magnetic field in which it is disposed.
[0028] With reference to FIG. 4 , it can be seen that the magnetic field provided by magnet 20 proximate the first magnetically sensitive device 12 is effected by the proximity of tooth 40 , whereas the magnetic field provided by the north pole of magnet 20 and in which the second magnetically sensitive device 14 is disposed is not affected by the direct proximity of a tooth 26 . Therefore, the first and second output signals provided by the first and second magnetically sensitive devices will be different from each other because of the different strengths and directions of the magnetic fields in which they are disposed.
[0029] If the first output signal provided by the first magnetically sensitive device 12 is identified as Hs because of its proximity to the south pole of magnet 20 and the second output of the second magnetically sensitive device 14 as identified as HN because of its proximity to the north pole of magnet 20 , the algebraic sum of these two signals can be represented by the waveform shown in FIG. 5 . As the rotatable member 24 is rotated about its centerline 34 , the algebraic sum of the first and second output signals will represent a generally sinusoidal waveform such as that identified by reference numeral 50 in FIG. 5 .
[0030] It should be understood that the precise shape of the waveform 50 is a function of the shape and configuration of the teeth of the rotatable member. The distance P between peaks of the waveform 50 represents the arcuate distance between adjacent teeth. When the first magnetically sensitive device 12 is disposed proximate a face 30 of a geartooth 26 , the algebraic sum of the first and second output signals reaches a maximum which can be negative or positive, depending on the position of the magnetically sensitive device relative to the magnet 20 . For example, negative peak 52 of waveform 50 would be representative of the disposition of the first magnetically sensitive device 12 directly over the outer surface 30 while the second magnetically sensitive device 14 is disposed directly over a space 28 .
[0031] FIG. 7 illustrates a system, which can be implemented in accordance with a preferred embodiment of the present invention.
[0032] It should be apparent that alternative dimensions between the first and second magnetically sensitive devices can be applied in alternative embodiments of the present invention. In addition, the relative angle of disposition between the sensor of the present invention and the central axis of rotation of the rotatable member can be varied. The effect on the waveform 50 by these alternative positions can significantly change the maximum and minimum values of the waveform and, in some cases, may change the general sinusoidal shape of the waveform or invert its peaks. However, these alternative embodiments should be considered to be within the scope of the embodiments disclosed herein.
[0033] If an electronic circuit associated with the present invention is provided with means for comparing the magnitude of waveform 50 to reference values, the circuit can provide additional information relative to the position of the teeth in comparison to the position of the first and second magnetically sensitive devices. For example, if a first reference magnitude 54 and a second reference magnitude 56 are compared to the magnitude of the waveform 50 a third output signal can be provided.
[0034] FIG. 6 shows the third output signal which is a square wave that is switched to a high output when the waveform 50 exceeds a first reference value 54 and switched low when the waveform 50 exceeds a second reference value 56 . It should be apparent that the second reference value 56 shown in FIG. 5 is a negative value and that waveform 50 exceeds that second reference value 56 when its value becomes more negative than the reference value.
[0035] A logic circuit can examine the results of the output pulses 60 of the third output signal and determine the position of the teeth relative to the sensor. For example, the presence of a high signal pulse 60 is representative of the presence of a tooth proximate the second magnetically device which, in turn, is disposed proximate the north pole of magnet 20 . By inverting the positions of the magnetically sensitive devices relative to the magnet, the waveform 50 can be inverted.
[0036] FIG. 7 illustrates a high-level block diagram of a system 70 , which can be implemented in accordance with a preferred embodiment of the present invention. System 70 generally includes a door latch assembly 711 , which is analogous to the door latch assembly 11 of FIG. 1 . Door latch assembly 711 also can be configured to include a gear 724 , which may be, for example, a gear associated with a motor that actuates one or more components of the door latch assembly 711 . System 70 also includes a geartooth sensor 720 , which is also integrated with the door latch assembly 711 . Geartooth sensor 720 is generally analogous to the sensor 20 depicted in FIGS. 1-4 herein. It can be appreciated, however, that geartooth sensor 720 can be implemented as one of many possible geartooth sensors.
[0037] One example of a geartooth sensor, which can be adapted for use in accordance with an embodiment of the present invention is disclosed in U.S. Pat. No. 5,304,926, “Geartooth Position Sensor with Two Hall Effect Elements,” which was issued to M. T. Wu on Apr. 19, 1994. Another example of a geartooth sensor, which can be adapted for use in accordance with an alternative embodiment of the present invention is disclosed in U.S. Pat. No. 6,404,188, “Single Geartooth Sensor Yielding Multiple Output Pulse Trains,” which issued to Lamar Ricks on Jun. 11, 2002. A further example of a geartooth sensor, which can be adapted for use in accordance with an alternative embodiment of the present invention is disclosed in U.S. Pat. No. 6,172,500, “Target Design for Geartooth Sensor with Minimal Number of Unique Segments Combined in Nonrepeating Fashion,” which issued to Robert Bicking on Jan. 9, 2001. U.S. Pat. Nos. 5,304,926, 6,404,188, and 6,172,500 are incorporated herein by reference.
[0038] FIG. 8 illustrates a system 80 , which can be implemented in accordance with an alternative embodiment of the present invention. Note that in FIGS. 7 and 8 , identical or similar parts are generally indicated by identical reference numeral. Thus, system 80 also includes door latch assembly 711 , including one or more gears 724 and one or more gears 720 . System 80 also includes a vehicle management module 82 , which can communicate with geartooth sensor 720 . Vehicle management module 82 provides a number of features. For example, vehicle management module 82 can communicate with the door latch assembly 711 for the control of the vehicle door latch assembly, including the motor and gears thereof. Additionally, vehicle management module 82 can calibrate one or more components of the door latch assembly based on data collected from the geartooth sensor.
[0039] Note that the term “module” can refer to a collection of routines and data structures that perform a particular task, a collection of tasks, and/or implements a particular abstract data type. Modules of this type can also be referred to as software modules and usually include a interface, which lists the constants, data types, variables, and routines that can be accessed by other modules or routines, and an implementation, which is private and only accessible to the module, and which contains the source code that actually implements the routines in the module.
[0040] Thus, a module can comprise an individual module or a group of modules (routines, subroutines, etc.) to form a single module. Vehicle management module 82 can therefore be implemented as a software module or a group of such modules which are stored within a memory location, preferably within a computer integrated with a vehicle, such as an automobile. Such a module can be retrieved from memory and processed via one or more microprocessors associated with the computer and/or vehicle.
[0041] The embodiments and examples set forth herein are presented to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and utilize the invention. Those skilled in the art, however, will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Other variations and modifications of the present invention will be apparent to those of skill in the art, and it is the intent of the appended claims that such variations and modifications be covered.
[0042] The description as set forth is not intended to be exhaustive or to limit the scope of the invention. Many modifications and variations are possible in light of the above teaching without departing from the scope of the following claims. It is contemplated that the use of the present invention can involve components having different characteristics. It is intended that the scope of the present invention be defined by the claims appended hereto, giving full cognizance to equivalents in all respects. | A latch assembly control method and, wherein a latch assembly is integrated with a motor having at least one gear thereof for actuating a plurality of components of the latch assembly. A geartooth sensor can be associated with the latch assembly, wherein the geartooth sensor senses a position of one or more gears, wherein the gear completes less than one revolution to thereby provide a known reference point registration and calibration of the latch assembly via data collected from the geartooth sensor. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. Non-Provisional application Ser. No. 14/827,151 filed on Aug. 14, 2015, titled, “Sleep Data Chain of Custody”, which claims priority to and the benefit of U.S. Provisional Patent Application No. 62/037,536 filed on Aug. 14, 2014, titled, “Sleep Data Chain of Custody”, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] This document is related to sleep monitoring/tracking, and more particularly to a system and method for establishing manageable, verifiable and accurate chain of custody for sleep monitoring/tracking data.
[0003] Establishing such chain of custody for sleep regulation is crucial as mandated rest periods for employees become more common. Rest periods fall into three primary categories: those that are required by law; those that are not yet required by law but are garnering public support for implementation (for example, for physicians and other health care workers); and those that employers electively require to promote safer workplaces.
[0004] Thus far, increased monitoring/tracking of sleep has proven successful. For example, in the decade ending in 2011 in the trucking industry, large truck crashes declined 26 percent from 5,111 to 3,757, because new sleep research showed that working long hours daily and weekly eventually caused chronic fatigue, slow reaction times and reduced ability to assess situations, including personal fatigue levels. As another example, in 2010 and 2011, federal agencies tightened regulations governing rest periods for both airline pilots and air traffic controllers due to research supporting links between adequate rest and safety. Other transportation industries, including railroad and shipping groups, have voluntarily implemented better policies requiring adequate rest for workers. Some industry groups including the U.S. Occupational Safety and Health Administration, Accreditation Council for Graduate Medical Education, and the consumer-advocacy group Public Citizen, have been or will be considering whether better sleep and/or rest requirements for health care workers might ultimately benefit both professionals and patients.
[0005] Currently, there is no way to effectively monitor compliance with sleep requirements (i.e., whether employees are actually taking mandated rests.) This does not honor the spirit of the law, which is to promote safer environments for workers and the public. It also makes assessing the efficacy of these regulations difficult.
[0006] Some trucking companies have “electronic logs” situated near steering wheels, which record when the motor is on or off, whether or not the trucker is off-duty, and gas mileage. These devices prevent truckers from taking unauthorized short-cuts or driving over the speed limit, but they do not track whether drivers are sleeping. In some instances, they are also noisy and distracting.
[0007] Some professionals, for example, pilots and physicians, may be mandated or requested to self-report fatigue, sleepiness or exhaustion. However, they may feel professionally pressured to underreport these experiences. Additionally, exhausted individuals may not be able to recognize their own state of exhaustion.
[0008] What is needed is a more effective solution than self-reporting or electronic logs.
SUMMARY
[0009] This document presents a wearable sleep tracking device that maintains chain of custody of sleep-related, and biometric data, which can include time an individual is asleep and time the individual is awake or alert. The sleep tracking device can track a large number of data sources to maintain and ascertain various compliance thresholds with one or more configurable sleep-related regulations or requirements.
[0010] In one aspect, a wearable device includes one or more biometric sensors. Each of the one or more biometric sensors to gathering biological data from a wearer of the wearable device, the wearable device further having a computer processor for receiving the biological data from the one or more biometric sensors and generating biometric information based on the biological data and according one or more biometrical algorithms. The biometric information includes validation information to validate the wearer as a source of the biological data gathered by each of the one or more sensors. In some implementations, the biometric information includes sleep information to provide or generate a sleep profile of the wearer.
[0011] In some aspects, a system can further include a transceiver coupled with the wearable device, the transceiver for transmitting the biometric information as a digital signal to one or more web servers via a communications network. The system can further include a chain of custody engine associated with the wearable device, the chain of custody engine to provide a chain of custody validation for the biometric information from the wearer to the one or more web servers.
[0012] In other aspects, a computer-implemented method includes the steps of gathering, by one or more biological sensors of a wearable device, biological data from a wearer of the wearable device, and generating biometric information by a computer processor of the wearable device based on the biological data and according one or more biometrical algorithms. The biometric information includes validation information to validate the wearer as a source of the biological data gathered by each of the one or more sensors, the biometric information further including sleep information to provide a sleep profile of the wearer. The method further includes transmitting, by a transceiver coupled with the wearable device, the biometric information to one or more web servers via a communications network. The method further includes maintaining, by the computer processor, a chain of custody of the biometric information from the wearer to the one or more web servers.
[0013] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other aspects will now be described in detail with reference to the following drawings.
[0015] FIG. 1 illustrates a wearable sleep tracking device and its component parts.
[0016] FIG. 2 is a block diagram of a wearable sleep tracking device and system.
[0017] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0018] This document describes a wearable sleep tracking device that gathers biometric information from a wearer, and that maintains chain of custody of sleep-related data generated from the biometric information.
[0019] The broad definition of chain of custody is considered as establishing the identity and integrity of physical evidence by tracing its continuous whereabouts. In the case of wearable sleep tracking devices, identity refers to the person whose rest was being monitored; for example, a truck driver, pilot, air traffic controller, or physician. Although the “evidence” collected and transmitted refers to physical quantities; for example, heart rate and other biometrics, here “integrity” refers to the direct and accurate relationship between the biometric data collected and the user. The chain of custody ascertains that the biometric data belongs to the user, throughout the data collection, transmission and aggregation processes. The data's “whereabouts” would be continuously monitored, user-tagged, assessed and stored in an impermeable loop between wearer and end-user.
[0020] The wearable sleep tracking device is configured to transfer data from the wearer to a centralized data aggregation and processing system. Examples of data might include actigraphy, GPS coordinates, time worn, and biometric data such as heart rate, EKG readings, skin temperature, and skin galvanic response. Thus, the wearable sleep tracking device can transmit data to a mobile phone or other intermediary device, which then transmits the data with or without processing via Internet pathways (wireless or otherwise) to a central server. In alternative implementations, the wearable sleep tracking device can include a transceiver for direct data transfer from the wearer to the central server. The central server traffics the data to a supervisor terminal or other consumption system.
[0021] In some implementations, the wearable sleep tracking device includes at least one sensor that is always in contact with the wearer, such as on the underside of a band, such that at random or programmed intervals the sensor takes a biometric reading to confirm that the authenticated user is wearing the device. This chain of custody confirmation can then be mapped by a computer with other data (GPS, timestamp, etc.) to determine if the wearer is in compliance. The ability to take a biometric reading without user interaction, such as requiring a wearer to touch a sensor, is important to validate chain of custody of the data collected and/or transferred by the wearable sleep tracking device while the wearer is asleep.
[0022] When the wearable sleep tracking device is unable to communicate to the central server, it will store any captured data locally for a period of time, until the next time it re-connects with the central server. Further, when the wearable sleep tracking device is not able to communicate directly to the centralized system, it communicates through a connected intermediary; i.e., a smartphone. This centralized system will analyze the data and provide data, information, and alerts to end-users. The chain of custody enables end-users to draw direct, accurate inferences regarding the wearer's episodic and/or accumulated rest patterns to ensure safety and legal compliancy. End-users include the wearer of the sleep tracking device, supervisors, regulatory agencies, etc.
[0023] In accordance with some preferred implementations, a device for maintaining chain of custody is a tamper-proof seal, akin to a lock snap. Physically this may employ the same technology as a plastic wristband: waterproof, lightweight, stretch-resistant, durable wristbands that lock into place with permanent locking snaps. The locking snap maintains chain of custody by assuring wearer connection with the sleep tracking device. If the wearer attempts to tamper with the device for removal or unauthorized transfer to another wearer (for example, a passenger in the vehicle) the tamper-proof seal would break.
[0024] For best compliance, the tamper-proof seal is preferably applied and monitored manually. This could introduce problems of inefficiency and manageability, requiring person-to-person examination of the tamper-proof seal for signs of damage. Given the physical effort that could be involved in some industries (for example, trucking) wearers with broken seals could make the plausible argument that the appearance of tampering, or a broken or missing lock, happened by accident. Applying, monitoring, repairing and replacing tamper-proof seals can be time-consuming and subject to human error.
[0025] While managed employees are subject to the company mandates and requirements provided by employers, independent contractors are not necessarily subject to these same requirements or may not be independently motivated to comply by applying tamper-proof seals. This creates issues of accountability, compared to managed employees. Tamper-proof seals interfere with functions related to recharging devices, or switching devices. (For example, an independently contracted trucker may ferry a container for one company on an outbound trip, but another company on the return trip. This makes tracking devices and users, and maintaining the chain of custody, a difficult task that becomes vulnerable to security breaches or data compromise.
[0026] Tamper-proof seals can be physically uncomfortable or distracting for drivers. Plastic wristbands and locking snaps are not designed for long-term use; most wearers limit use to hours or an evening; for example, a theme park or music concert. The cumbersome design could become irritating on long-distance trips because of shape, texture and other factors. Tamper-proof seals might potentially suggest a lack of trust between an employer and driver, resulting in the psychological factor of increased resentment at the notion of always being tracked. This could decrease wearer buy-in for the program, since the seal offers no compensatory benefits.
[0027] Accordingly, in some alternative implementations of a device for maintaining chain of custody, heartbeat and ECG information from a wearable device are used to authenticate that the data stream is coming from a specific user. Heartbeat authentication functions the way traditional fingerprinting functions: an individual's unique heartbeat pattern can provide positive identification. Heartbeats can securely communicate a wearer's identity to devices, including wearable devices. Cardiac rhythms function as smart passwords, wirelessly transmitting identity to wireless devices.
[0028] In some implementations, wearers place a finger on the device's top sensor, and allow their wrist to contact with the device's bottom sensor, completing an electrical circuit. The device alerts wearers than an electrical circuit has been completed by vibrating and illuminating LEDs. Wearers remain “authenticated” until the device is removed. In some cases, a “three factor security system” helps maintain the chain of custody. The system requires three factors present to complete the positive ID loop: a) the heartbeat tracking device b) the unique heartbeat and c) a third device, such as a smartphone, registered to the device application.
[0029] This concept combines heartbeat and ECG sensor and software with sleep tracking sensors and software available in existing consumer fitness and sleep trackers. The device's sensor and software maintains positive identification of the wearer, assuring that the wearer remains the same throughout data collection, transmission, and aggregation. The device can be removed for comfort, or during non-working hours. Further, the device can re-establish chain of custody through biometric authentication solely by the wearer.
[0030] Sleep tracking sensors and software monitor the wearer to determine periods of activity and rest. Data for body temperature, heart rate, movement and other factors can be assessed for indicators of adequate rest or sleep. If the sleep tracking and chain of custody data stream is tied to a GPS data stream (i.e., from a smartphone) then it can be inferred that the wearer of the device is at a specific location, within a margin of error (+/−30 feet) if the device is connected to the GPS via Bluetooth. The system can dynamically, in real time, respond to changes in location information and update or alert the supervisors as appropriate.
[0031] In some implementations, an exception can be made for when the wearer leaves the planned route/corridor can be preprogrammed into the system, or dynamically updated through human interaction. For example, alerts can be sent if the wearer leaves the preset route, or conversely, the tracking can be switched off if the wearer leaves the route.
[0032] This process can track mandated rest periods, and determine if the user is driving or not. In some implementations, an algorithm used by the wearable sleep tracking device is configured to determine between sustained driving versus in-town commuting. The system can switch off as needed or desired to accommodate truckers who are still wearing the device but no longer require the supervision or management of employers or regulatory agencies.
[0033] In accordance with the disclosure herein, a wearable sleep tracking device can maintain public safety by ensuring that regulated employees, such as truckers, pilots and air traffic controllers, receive the mandated rest periods required by federal agencies. The device and system can calculate metrics and values in a repeatable and automated matter to ascertain characteristics associated with sleep and rest.
[0034] FIG. 1 illustrates a wearable sleep tracking device 100 , which is configured to be worn, attached to, or otherwise affixed to a part of a wearer's anatomy. The sleep tracking device 100 in FIG. 1 is shown as a bracelet or ankle cuff, but can be any type of attachable or wearable structure. The sleep tracking device 100 includes an input/output module 102 that can contain a transceiver or other I/O port, a communications module 104 that can format information collected by the sleep tracking device 100 in a format that can be transmitted by the input/output module 102 , and one or more biometric sensors 106 . The biometric sensors 106 can include, without limitation, a heartrate sensor, a breath rate sensor, a body temperature sensor, a blood pressure sensor, a sleep sensor, or other biometric sensor.
[0035] The sleep tracking device 100 further includes a user display 108 for displaying information collected by the one or more biometric sensors 106 , or received by the sleep tracking device 100 via input/output module 102 . For instance, the user display 108 can display feedback or instructions from a monitoring entity that monitors the wearer's sleep status remotely. The user display 108 can also display real-time data such as time, location, task or task status, or the like. The sleep tracking device 100 can further include an accelerometer 110 for monitoring acceleration and movement of the wearer of the sleep tracking device 100 . The sleep tracking device 100 further includes a logic processing unit 112 for processing information collected by the sleep tracking device 100 via the one or more biometric sensors 106 , or from the input/output module 102 , or even the user display 108 (if the display also functions as a touch-sensitive input device). The sleep tracking device 100 may include a battery 114 or other power source. All of the above components of the sleep tracking device 100 can be housed in a housing 101 , which can take any of a number of forms.
[0036] FIG. 2 is a block diagram of a sleep tracking system 200 . The system 200 includes one or more wearable devices 206 , as substantially described above, which are in communication with a mobile device 204 and/or industry computing console 208 . The industry computing console 208 can be programmed with logic to process and manage data to and from the wearable devices 206 . The mobile device 204 can be associated with a wearer of the wearable device 206 . In some implementations, communication can be executed through the internet 202 , although other communication mediums can be utilized.
[0037] The system 200 further includes user devices 210 , such as any number of computing devices used by the wearer or other employees or customers associated with the wearer, and manager devices 212 . The manager devices 212 can include any number of computing devices that are pre-programmed with logic to assist a manager to monitor the activity of a wearer, such as described below. The system 200 further includes a central server 214 that can store some or all of the data accumulated or transmitted by the various computing devices or wearable devices of the system 200 .
[0038] The systems and methods described herein can assure that the metrics and values represented by a device assigned to a particular wearer actually represent the wearer himself/herself rather than another party. These systems and methods provide this chain of custody in a manner that is manageable, feasible and cost-effective for employers, supervisors and regulatory agencies. Finally, the system and method provide this chain of custody in a manner that minimal disruption, discomfort, inconvenience, and intrusion for truckers and other wearers.
[0039] Wearers can self-monitor in order to independently and individually plan travel and rest times, assuring compliance with employer or legally mandated rest times. For instance, long-distance truckers have complained that adhering to rest regulations meant sometimes parking in unsafe areas for mandated rest. Planning ahead for primed sleep could help truckers locate safe, geographically optimized destinations for rest if wearable devices were synced with GPS data banks. In this context, supervisors can monitor data remotely from the wearable device to identify wearers who are intentionally or unintentionally not meeting required rest specifications. Supervisors could intervene as wearers approach non-compliance, by sending messages or alerts to the wearable device or other communication device, to remind wearers to plan for upcoming rests. Supervisors/logistics managers could also integrate sleep/rest intervals into route planning and other logistics systems.
[0040] Conversely, supervisors could monitor wearer wakefulness. For example, if heart rates, etc. were indicative of oncoming sleepiness in a truck driver or air traffic controllers, supervisors could intervene via alerts or other communication to prevent sleep onset. Regulatory agencies can monitor data depending on desired or legally required intervention levels. For example, companies with a record of non-compliance, or higher-risk industries, could be monitored more closely for non-compliance. Other external agencies, such as research institutions, might partner with employers for monitoring in order to research topics related to sleep, rest, safety, etc. and collect relevant data.
[0041] The system functionality could be integrated into logistics planning software so rest periods/downtime can be accommodated as part of the logistics planning, similar to how load weight and routing are factored into route planning. Because the wearable can provide real time, objective data on the activities of the wearer, this information can be used to customize any program to the specific behaviors of the wearer. For example, a cognitive behavior program can constantly change and adapt to address the issues that the wearer is experiencing at the time.
[0042] The systems and methods described herein offer practical, appealing incentive structures for worker compliance. For instance, in the trucking context, trucker compensation is often calculated based on a fee-mile-structure. To incentivize adoption and compliance for truckers, who may resist sleep or rest that interferes with their ability to quickly log miles, per-mile compensation can be increased. Although truckers completing required rest stops will necessarily be travelling more slowly, this slower pace will be offset by higher compensation rates for complying with mandated rest stops.
[0043] The systems and methods described herein also offer practical, appealing incentive structures for adopting companies. For example, motor vehicle crashes, including those that involve trucks, result in higher insurance premiums, wasted fuel (idling time, spilled fuel, etc.) and other costs ( 15 ). In some implementations, savings from lower premiums can be passed on as incentives for increasing the trucker mileage payments. Consumers (in this case, insured drivers) may be willing to trade increased transparency—via on-board diagnostic systems (OBDs) to track data such braking time, speed, etc.—for the possibility of lower insurance rates. Companies and drivers can log onto the system's real-time incentive tracking feature for estimates and real-time calculations on their projected discounts/incentives based on adopting the sleep-tracking wearable device chain of custody system.
[0044] Although a few embodiments have been described in detail above, other modifications are possible. Other embodiments may be within the scope of the following claims. | A wearable device includes one or more biometric sensors, each of the one or more biometric sensors gathering biological data from a wearer of the wearable device, the wearable device further having a computer processor for receiving the biological data from the one or more biometric sensors and generating biometric information based on the biological data and according one or more biometrical algorithms, the biometric information including validation information to validate the wearer as a source of the biological data gathered by each of the one or more sensors, the biometric information further including sleep information to provide a sleep profile of the wearer. | 6 |
FIELD OF INVENTION
This invention relates to the processing of pastries by dividing them into accurately proportioned pieces, and separating the pieces with a separator such as a piece of coated paper.
BACKGROUND OF THE INVENTION
A familiar sight in restaurants is a server attempting accurately to cut a cake or pie and get the pieces out of the pan or off of the plate in a unitary and appealing condition. Especially for the first piece, the attempt is usually far from successful and often ends up as part of a server's meal. As a consequence, fewer than optimum slices are frequently produced, because of damage or because of inaccurate proportioning of the slices.
Such wastage is never to be encouraged, and some efforts have been made to overcome the difficulties. The most common expedient is a template applied over the pastry which is used as a guide for the knife. This is slow manual labor, and still leaves the pieces unseparated even though they have been cut apart.
There has been an effort, exemplified by Meier U.S. Pat. No. 4,299,148, to insert a separator between each pair of adjacent pieces, utilizing a template as a guide for a knife which drives the separator into the pastry. In this device the user manually inserts the separators with as many individual manipulations as there are to be pieces. This is a slow, inefficient device and technique, which requires many inefficient movements, each of which can involve the risk of error or spoilage.
It is an object of this invention to provide a processor to divide pastries and to insert separators between adjacent pieces in an accurate and expeditious way. Manipulations can be reduced by half, and the processor can be constructed in a way that it can readily be cleaned and maintained to food handling standards.
The term "pastries" is used generically to encompass all types of edibles that are to be divided into wedge-shaped portions. Examples are pies and cakes, and also the more exotic desserts such as mousse pies and the like. The costliness of some of these products is such that restaurants and bakeries can no longer afford the wastage which is so frequently attractive to the servers.
BRIEF DESCRIPTION OF THE INVENTION
A pastry processor according to this invention has a base frame and a turntable mounted to the frame. A head column is mounted to the frame, and a vertical blade track is formed on it. A blade carrier carrying a blade is reciprocally mounted to the track so the blade is moveable up and down relative to the turntable (and thereby to a pastry on the turntable). A support above the turntable has a support surface on each side of a slot. A separator can rest on these surfaces, bridging the slot. When the blade's edge passes through the slot, it folds and carries with it the separator, driving it into the pastry while it divides the pastry.
Indexing means steps the turntable an appropriate increment after each removal of the blade, and cycling means can be provided as appropriate and desired to automate the processor.
Sensing means senses the approach of the blade edge to the turntable to reverse the blade when the separation is concluded.
According to preferred but optional features of the invention, the head column is vertically moveable to adjust the height of the support and of the blade relative to the turntable; the turntable can be slidably mounted so as more readily to be loaded and unloaded; and the sensing means is a depending member whose contact with structure associated with the turntable causes reversal of the blade's movement.
According to yet other preferred but optional features of the invention, a pair of support members is provided so that two separators can be inserted at one time, one on each side of the central axis, and the supplies and separators can similarly be doubled.
The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the presently preferred embodiment of the invention;
FIG. 2 is a top view of a circular pastry divided by the processor of this invention;
FIG. 3 is an enlarged fragmentary cross-section taken at line 3--3 in FIG. 2;
FIG. 4 is a side view showing a portion of the invention;
FIG. 5 is a cutaway view of a portion of the pedestal of this invention;
FIG. 6 is an enlarged section of a portion of FIG. 5; and
FIG. 7 is a fragmentary section taken at line 7--7 in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is shown a pastry processor 10 whose function it is to divide a circular pastry in the manner shown in FIGS. 2 and 3. In FIG. 2 there is shown a circular pastry 11 divided into four portions 12, 13, 14, 15. There can of course be fewer or more portions, and it is an advantage of this device that it can optionally be adjusted to divide the pastry into any desired number of pieces. The objective is to separate the pieces by forming a separation (gap) between each of them.
In FIG. 4 because they are all alike, only separation 16 between portions 12 and 15 will be described in detail. A blade 17 is shown which has driven a separator 18 between the portions while it divided them. To this action, a separator will be folded over the edge 19 of the blade so as to have two fold sides 20, 21 which cover the sides of the blade.
The paper is treated so as not to adhere strongly to either the blade or to the pastry. It may be a wax impregnated or plastic coated paper, for example. The fold sides should be tall enough to rise above the pastry, because otherwise the blade will become soiled, and after awhile will not make clean cuts. Also, the separator protects the sometimes sticky sides of the portions from each other.
It is an advantage of this construction that the blade remains clean except for a small region at the very center of the pastry where separators will have been brought as close together as possible. Therefore the resulting product will be a pastry accurately divided into a plurality of portions with each adjacent pair of portions separated by a separator from which the portions can readily be removed, and from which portions of the exposed separators can also be readily removed. As a consequence, pastries can be processed either at individual restaurants or more usually at a central processing plant where the baking has taken place. The product should be frozen to a soft frozen consistency so as more easily to be divided by this technique without undue distortion by crushing or the like. The blade will ordinarily be made as thin as possible, with a slightly rounded edge so it will not cut the separator. The separator itself is only thick enough that it is sufficiently rigid to make the cut and will not cut the separator. About 0.010 inches thick is a suitable dimension for the blade.
FIG. 3 illustrates a pan 23 or base beneath and supporting the pastry. This pan or base is rested on turntable 25. Turntable 25 is also shown in FIG. 1. It has a vertical central axis of rotation 26 with which the center of the pastry will be coincident while the pastry is being divided. A plurality of fingers 27 which are softly flexible will be provided to assist in centering the article, and will generally be brought to bear against the pan or base beneath the pastry article so as to keep it centered without damaging it.
The processor itself has a base frame 30 mounted on feet 31, at least one of which will customarily be equipped with a leveller such as a screw that is threaded upwardly into a respective one of legs 32. The frame includes a top 33 with a recess 34. Slide rails 35 in the recess receive a carriage 36 to which the turntable is rotatably mounted. The carriage is axially slideable along the rails as shown by arrow 37 along a horizontal axis. A crumb tray 38 is placed in the bottom of the recess. It can be removed through an opening in the side of the frame.
The carriage is shown in a first carriage position wherein the central axis 26 of the turntable is aligned with and is coincident with plane of blade 17. It is conveniently maintained in this position by a spring catch (not shown) which upon release will enable a bias spring 39 (not shown) to move the carriage to the right to a second position in FIG. 1 so that the turntable will be more accessible to an operator standing at the right hand face 40 of the processor. This enables convenient loading and unloading of the pastry. The carriage will simply be pushed manually against a spring-load resistance to the illustrated first position and retained there by a catch until released upon completion of the cycle. Then the spring load will return the carriage to the second position nearer to the operator.
A head column 45 is mounted to the frame. It rises above the frame. If the processor is adapted to work on only one thickness (height) of pastry, then vertical adjustments will be unnecessary. The length of the separator divided by two will be the approximate height of its free edges above the base of the cake. There should not be an excessive height of separator above the top of the pastry. For a one inch cake, for example, it is not suitable for there to be two or three inches of loose separator material above the cake surface, because it spoils the appearance. Therefore if the device is to be made adaptable to dividing pastries of various thicknesses, it must be adaptable to insert appropriate various sizes of separator material. For this purpose, the head column will be made vertically moveable, as will later be described.
To the head column there is fixedly mounted a support 50 which, when two separators are being inserted at one time will include two support elements 51,52. Because both of these elements are identical, only element 51 will be described. It is best shown in FIG. 4. It has a pair of support surfaces 53, 54, one on each side of a slot 55, which slot passes the blade. At the end of support surface 53 there is a stop 56 which is adjustably moveable to be abutted by a separator 57 laid atop the two support surfaces and bridging the slot. Surface 54 curves upwardly so that the tendency of the separator will be to slide against stop 56. Adjusting the position of stop 56 accommodates various lengths of separators, so that separators of different heights when placed in the pastry can be handled. Members 51a and 52a are slidable relative to central part 60 to accommodate separators of different widths so as to fit in pastries of various diameters. Clamps such as clamp 58 provide for these adjustments.
It will now be seen that the separator will be placed upon the support surfaces and then the blade will be driven through the slot, so as to engage the separator, and fold it in two with its sides against the blade. The bottom of the support should not be so far from the top of the pastry that the separator material can get loose and drag along the top while it is inserted in the pastry. The edges of the slot will hold the separator material reasonably close to the blade until this risk is over, meaning that clearance above the pastry should not ordinarily exceed about 1/2 to 1/4 inch.
The head column carries a blade track 65 (FIG. 5) to which there is mounted a blade carriage 66 for up and down movement as shown by arrow 67. It is this reciprocation that causes the dividing of the pastry and the insertion of the separator. Obviously it is neither necessary nor particularly desirable for the stroke of the blade to be any longer than necessary, and its lower edge rises above the support surfaces only far enough that the separator can conveniently be set into it, and then the edge is lowered until it is just about in contact with the base which supports the base of the pastry being divided. When the bottom of the support is brought as close to the top of the pastry as practicable, then the stroke need be no more than the height of the pastry plus about one inch. The blade itself is held by a holder 68 in the blade carriage. The blade is not shown in FIG. 1, in order to simplify the drawings.
Above the blade there is disposed a pair of storage bins 69, 70 in which stacks of separators 71, 72 are held. The operator will take one in each hand and place one in each support element when two separators are inserted. Should only one-half of a diametral cut be desired, then a shorter blade will be used, and only one separator. This machine is adaptable for that purpose as well.
Above and well away from the blade are placed two actuator switches 73, 74. These switches will be connected in series so that the operator must close both of them at the same time in order to start the sequence. They are far enough away from each other that they cannot be actuated by only one hand. Thus automatic sequence will be started when only the two switches are simultaneously closed.
Should the machine be adapted only for a single height of pastry there need be no vertical adjustment of the head column. However, a practical machine for use in bakeries should be useful for dividing pastries of at least several heights. There is provided, as best shown in FIG. 5, a jack screw mechanism 75 having a hand wheel 76 exposed at the top to be turned by the operator. The jack screw is mounted to the head column by a grommet 77 at the top and a threaded bushing 78 near its bottom. It projects downwardly below the bearing to bear against a tongue 79 which is fixed to the frame. Turning the jack screw in bushing 78 so as to extend some of its length below the bushing causes the head column to rise, and turning it the other way will cause it to lower. The head column will be mounted to the frame by means of a vertical track engagement (not shown) which gives lateral sliding support for vertical movement of the column relative to the frame subject only to being limited by contact with the tongue 79 against farther downward movement.
The above arrangement enables the head column to be moved upwardly and downwardly as a unit, carrying the track, the blade carrier (and a blade), the supports, and the sensing means to be described, along with it. This enables the clearance to be adjusted between various heights of pastry and the support. It also enables the length of the blade stroke to be adjusted so it is shorter for pastries of lesser thickness than for pastries of greater thickness. Of course, the objective is always to stop the blade at a lower elevation adjacent to the turntable or plate. The upper elevation of the blade carrier varies according to the adjustment of the height of the head column.
Sensing means 85 is carried by carriage 66. A mounting block 86 is rigidly fixed to carriage 66. It supports a lower limit switch 87 which faces downwardly. A hole 88 through block 86 passes sensing shaft 89 for free vertical sliding motion.
A contact plate 90 has a flat surface 91 closely spaced from carriage 66 so it will not rotate. It extends beneath switch 87, and has a threaded hole 92 to which shaft 89 is threaded by a thread of one hand and selected pitch. A second portion 93 of the shaft is threaded into the upper portion 94 by a thread of same hand but of different pitch. This gives a fine adjustment to "lengthen" or "shorten" the shaft.
As best shown in FIG. 7, portion 93 has a non-circular section 95 slidably fitted in a contact plate 96. Portion 93 cannot rotate. Portion 94 can be rotated by turning ball 96 on an upper shaft portion 97, to when the ball is keyed. Portion 97 has a crosspin 99, slidable in an axial slot in portion 94. Turning the ball rotates portion 94, and because of the thread pitch differential, the effective length of the sensing shaft can finely be adjusted to account for different thicknesses of discs beneath the pastry. It gives a variability of sensing position relative to the turntable.
Also, the ball can be lifted up, to pull the entire shaft with it so as to make control contact to retract the blade at any time, as will be understood later. Its cross pin engages the upper end of the slot. This is a convenience in maintenance and cleaning, as well as providing for fast retraction any time in the sequence.
Drag means 105 is mounted to the carriage. This may be a spring-loaded friction block, which prevents axial movement of shaft portions 93 and 94, unless a strong enough force is exerted. This becomes a type of mechanical "memory" to hold the shaft in an adjusted position until the next reversal of movement. Persons skilled in the control art will recognize that other mechanical systems could be used, as well as electronic cycling systems, for sequencing and memory.
A contactor 110 extends laterally from the lower end of the shaft 93. It overhangs tongue 79. When the carriage moves downwardly to where reversal should occur, it stirkes the tongue as shown in phantom line. Continuing downward movement of the blade carriage forces the shaft upwardly relative to the carriage, and contact plate 90 contacts switch 87 to stop downward movement. Motor 111 drives the carriage through a looped chain 112 connected to the carriage by a joinder 113. Suitable connections will be made between the switches and the motor, which will be evident to persons skilled in the controls art.
Limitation on upward movement of the blade carriage is caused by actuation of limit switch 120 mounted to the frame while at the same time releasing "memorized" contact plate 90 from switch 87, which is accomplished by contactor 110 stoping against adjustable stop screw 115, and the motor will stop.
A motor 125 (FIG. 1) is mounted to carriage 36, and is linked to the turntable to turn it by an appropriate number of degrees after each separation is made. A pulse-counting stepper motor is useful because it can provide a wide range of portion sizes. However, this is merely one form of indexing means. A quite suitable alternative technique is mechanical rather than "pulse counting". An indexing plate may have holes or dowels respective to the desired number of pieces, and may rotate to a mechanical stop such as a solenoid plunger which can be released to enable the turntable to be released to rotate to the next stop. The turntable would be driven by a continuously operating motor through a slipclutch. This illustrates the wide range of suitable indexing devices.
The control logic is as follows. The pastry is loaded on the turntable with carriage 36 in its second position, away from the vertical axis. Then the carriage is shoved to its first position in alignment with the vertical axis. The two power switches are pressed and motor 111 drives the blade carriage downwardly, until the contactor 110 strikes tongue 79 and the blade carriage moves far enough relative to sensing shaft 85 to change the condition of switch 87. This stops downward movement. If desired, upward movement could be arranged independently of motor 111, but it is useful simply to reverse it at this time by an automatic sequencing operation, and upward movement will continue until contactor 110 strikes stop screw 115 to cause the shaft 89 to shift downwardly relative to the blade carriage, and limit switch 87. Upward movement continues until switch 120 is contacted. Then upward movement stops, and the turntable will be turned through its predetermined angle, and the cycle will be repeated. Preferably means which stops the turntable after the pastry is rotated 180 degrees (180°) (for a double cut) or 360 degrees (360° ) (for a single-sided cut). Carriage 36 will then be released to move to its second position, conveniently by cycling circuit means.
Adjustment of the head column using jack screw 75, and of the effective length of the sensing shaft 89 will be understood from the foregoing.
All of the foregoing results in a machine which can readily and reliably insert separators into pastries of various diameters and heights at predetermined angular intervals. The device is simple and rugged in construction and is able to be cleaned in accordance with good food machinery practice.
This invention is not to be limited by the embodiments shown in the drawings and described in the description, which are given by way of example and not of limitation, but only in accordance with the scope of the appended claims. | A machine to divide pastry into portions, leaving a separator at each separation. A turntable supports the pastry, and a blade descends to drive the separator into the pastry. The turntable is rotated incrementally, and the blade's stroke and initial height are adjustable to accommodate pastries of various heights. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Australian Provisional Patent Application No 2006902915 filed on 31 May 2006, the contents of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a compacting wheel apparatus of the type fitted to earthmoving machinery for compacting soil, particularly in trenches.
BACKGROUND
It is a requirement in cable- and pipe laying, and civil engineering in general, to compact soil in a trench, or other confined space, to return the soil to its original grade. For reasons of cost, safety and consistency of results, it is normal to fit a rotatable wheel or drum to a suitable earthmoving machine, the wheel or drum being rolled back and forth over the soil area to be compacted until a suitable level of compaction is obtained.
FIG. 1 shows one such arrangement. A wheel-type compacting device 1 is mounted to a backhoe excavator 2 in place of the usual bucket. The device 1 is able to rotate freely about an axis 3 that is parallel to the axes 4 and 5 about which the backhoe's dipper (sometimes alternatively called stick) 6 and boom 7 rotate. The backhoe operator positions excavator 2 so that axes 4 and 5 are perpendicular to the length of a trench 8 . The operator can then readily position the device 1 at the base of the trench, and by operation of boom 7 and stick 6 , roll the device backwards and forwards along the trench to compact the soil therein. The device 1 is typically provided with radially projecting feet 9 to enhance the compaction effect but may also take the form of a plain-surfaced wheel or drum.
In some circumstances vibration devices may be employed with the device 1 for better compaction, and sometimes no vibration capability is provided, reliance being placed simply on repetitive pressing downward of the soil surface by the feet of the wheel.
Other types of machines may be used for mounting the compacting devices such as device 1 . For example, device 1 may be mounted to other types of excavators, such as telescopic-boom excavators (sold by Gradall Inc., USA), and to the boom-and-stick backhoe arrangements that are often fitted to the rear of wheeled loaders. With suitable adaptors, front-end loaders of the articulated or skid steer type may also be fitted with compacting devices.
Compacting devices that comprise a single drum with feet projecting therefrom and which is supported for rotation between fork arms can lead to difficulties in compacting soil adjacent the walls of a trench. This may be due to the fact that the fork arms are of a size that can prevent the drum accessing the soil at the perimeter of the trench, adjacent the longitudinal walls of the trench. It is therefore known to provide compacting devices, such as device 1 , that employ several individual wheel disks 10 on a common shaft, with supporting members 11 arranged therebetween. In the arrangement as shown in FIG. 1 , supporting members 11 are secured to a structure 12 releasably attached to the stick 6 and provide support for an axle (not shown) on which are mounted the wheel disks 10 .
However, devices of this type, have their own problems. Gaps are needed between some wheel disks 10 to provide clearance for the support members 11 and the ground below such gaps receives no significant compaction. Therefore, to provide adequate and even compaction over the whole width of a trench floor, it may be necessary to shift the device 1 laterally one or more times to ensure that all the soil within the trench is compacted. This can be a time consuming process that requires significant operator skill in manoeuvring the machine.
Therefore, there is a need to provide a compacting device that provides improved soil compaction in a relatively simple manner.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
SUMMARY OF THE INVENTION
In a first aspect, the invention provides a compacting device for attachment to an earthmoving machine to compact a substrate, including:
a plurality of wheel assemblies mounted for rotation together in bearings; and
a support having a base adapted to be mounted to the earthmoving machine and one or more bearing support members that extend from the base and between the wheel assemblies to support the bearings;
wherein each wheel assembly includes a set of ground-contacting feet secured to and peripherally spaced apart around a rim portion of the wheel assembly such when the device is rolled over the substrate a first foot of the set of ground engaging feet contacts the substrate between axial width limits that differ from axial width limits of a second foot of the set of ground engaging feet.
In one embodiment, the axial width limits of the first foot partially overlap the axial width limits of the second foot. The first and second feet may be peripherally adjacent members of said set of feet.
The first and second feet may be comprised in a multi-foot pad secured to the wheel assembly. The multi-foot pad may comprise two feet only of the set of ground engaging feet. Conveniently, the first and second feet may be integrally formed in said multi-foot pad.
The multi-foot pad may be secured to the wheel assembly by at least one of welding, bolting, riveting, and pinning by means of at least one pin. In another form, the multi-foot pad may be formed integrally with the wheel assembly by casting or the like.
In another embodiment, for ease of fitting, the multi-foot pad has locating surfaces that, when the multi-foot pad is placed on the wheel assembly for securing thereto, bear against the wheel assembly so as to correctly position the feet radially and/or axially on the rim portion of the wheel assembly. This arrangement may be particularly convenient when the multi-foot pad is to be secured by welding.
The multi-foot pad may have a groove within which the rim portion of the wheel assembly is received so as to locate the multi-foot pad on the wheel assembly axially and radially.
In another embodiment, when the multi-foot pad is secured to the rim portion of the wheel assembly, the axially leftmost width limit of the first foot is on an opposite side of the rim portion of the wheel assembly from the axially rightmost width limit of the second foot.
The first and second feet of the multi-foot pad may have approximately the same shape as each other, save for being oppositely handed in an axial direction, and wherein when the multi-foot pad is secured to the wheel assembly the first and second feet may be approximately equally displaced in opposite axial directions from the rim portion of the wheel assembly.
At least one of the wheel assemblies may include an endmost wheel assembly that may be secured to an outermost wheel assembly of the device to increase its working width.
In another embodiment, the compaction device or the machine to which it is mounted may be provided with means for vibrating the wheel assemblies to enhance the compaction effect where required.
In a further aspect, the invention provides a multi-foot ground engaging pad for a compacting device of the type having a wheel assembly comprising one or more wheels adapted to be rolled over a substrate to be compacted, the pad including a plurality of ground engaging feet integrally formed on a base that is securable to a rim portion of the one or more wheels whereupon said feet are spaced peripherally on said wheel.
In an embodiment of this aspect, during rolling of the wheel assembly on the substrate, a first ground engaging foot on the pad contacts the substrate between axial width limits that differ from axial width limits of a second ground engaging foot on the pad.
In one form, the axial width limits of the first ground engaging foot may partially overlap the axial width limits of the second ground engaging foot.
In one embodiment, the multi-foot pad may comprise two ground engaging feet only. The multi-foot pad may be securable to the wheel by at least one of welding, bolting, riveting, and pinning by means of at least one pin.
The multi-foot ground engaging pad may have locating surfaces that, when the pad is placed on the wheel for securing thereto, bear against the wheel so as to correctly position the ground engaging feet radially and/or axially on the wheel. A groove may be provided within which an outer rim of the wheel may be received so as to locate the pad on the wheel axially and radially.
The multi-foot pad may be so proportioned that when the pad is secured to the wheel the axially leftmost width limit of the first foot is on an opposite side of a rim portion of the wheel from the axially rightmost width limit of the second foot. The first and second ground engaging feet of the pad may have approximately the same shape as each other save for being oppositely handed in an axial direction. In this regard, when the pad is secured to said wheel the first and second feet may be approximately equally displaced in opposite axial directions from the rim portion of the wheel.
In a still further aspect, the invention provides a method for compacting soil including the steps of:
securing a compacting device as disclosed herein to an earthmoving machine; and
using the machine to roll the device back and forth on a surface of the soil.
In one embodiment of this aspect of the invention, the earthmoving machine may include a backhoe mechanism having a boom and a dipper and the device may be secured to a free end of the dipper.
According to yet another aspect, the present invention provides a compacting device for attachment to an earthmoving machine to compact a substrate, the compacting device including:
a base adapted to be mounted to said earthmoving machine;
one or more support members extending from the base;
one or more bearings, the or each bearing being mounted to an end of the one or more support members;
a shaft rotatably supported within the one or more bearings; and
a plurality of wheel assemblies mountable to said shaft such that said one or more support members extend between said wheel assemblies;
wherein each wheel assembly includes a plurality of ground-contacting feet spaced apart around the periphery of the wheel assembly, said feet being alternately displaced laterally towards opposing sides of the wheel assembly such that when said wheel assemblies are rolled over a substrate surface said feet contact said substrate surface and compact said substrate.
In an embodiment of this aspect of the invention, the wheel assemblies are mountable to the shaft such that the ground contacting feet of adjacent wheel assemblies are circumferentially staggered.
In one form, at least two of the wheel assemblies may be directly mounted to the shaft. At least one wheel assembly may be mounted to one of the wheel assemblies directly mounted to the shaft.
Each ground contacting foot may be formed integral with at least one adjacent ground contacting foot to form a multi-foot pad attached to a rim portion of each wheel assembly. The multi-foot pad may have two ground contacting feet only. The multi-foot pad may be secured to the rim portion of the wheel assembly by at least one of welding, bolting, riveting, and pinning by means of at least one pin.
In one form, the multi-foot pad may have locating surfaces that, when the multi-foot pad is placed on the rim portion of the wheel assembly for securing thereto, bear against he rim portion of the wheel assembly so as to correctly position the ground contacting feet radially and/or axially on the rim portion of the wheel assembly. In another form, the multi-foot pad may have a groove within which the rim portion of the wheel assembly may be received so as to locate the multi-foot pad on the rim portion of the wheel assembly axially and radially.
In another embodiment of this aspect of the invention, the first and second feet of the multi-foot pad may have substantially the same shape. In this regard, when the multi-foot pad is secured to the rim portion of the wheel assembly the first and second feet may be approximately equally displaced in opposite lateral directions from the rim portion of the wheel assembly.
According to yet another aspect, the present invention provides a compacting device for attachment to an earthmoving machine to compact a substrate, the compacting device including:
a base adapted to be mounted to said earthmoving machine;
one or more support members extending from the base;
one or more bearings, the or each bearing being mounted to an end of the one or more support members;
a shaft rotatably supported within the one or more bearings; and
a plurality of wheel assemblies mounted on said shaft such that said one or more support members extend between said wheel assemblies, each wheel assembly having a plurality of ground-contacting feet spaced apart around the periphery of the wheel assembly such that when said wheel assemblies are rolled over the substrate surface said feet contact said substrate surface and compact said substrate,
wherein, one or more additional wheel assemblies are removably mounted to one or more of the plurality of wheel assemblies mounted on the shaft.
In an embodiment of this aspect of the invention, the one or more additional wheel assemblies are removably mounted to an end wheel assembly mounted on the shaft. The one or more additional wheel assemblies may be removably mounted to a hub that is removably mounted to an end wheel assembly mounted on the shaft.
The hub may comprise a first mounting disc for mounting said hub to a wheel disc of an end wheel assembly mounted on the shaft and a second mounting disc to which said additional wheel assembly is mounted. The first and second mounting discs may have a plurality of holes formed therethrough to receive one or more fasteners for facilitating mounting of the hub to the end wheel assembly and mounting of the additional wheel assembly to the hub. The plurality of holes may be formed around the periphery of the first and second mounting discs. Corresponding holes formed around the periphery of the first and second mounting discs may be offset such that the plurality of ground-contacting feet spaced apart around the periphery of the additional wheel assembly are circumferentially staggered with respect to the plurality of ground-contacting feet spaced apart around the periphery of the end wheel assembly when the additional wheel assembly is mounted to the end wheel assembly.
Other aspects and features will become apparent from the following detailed description.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example only, the invention is now described with reference to the accompanying drawings:
FIG. 1 is a perspective view of a backhoe excavator fitted with a compacting wheel of known type;
FIG. 2 is a schematic diagram showing (upper part) a rear view of a compacting wheel and (lower part) a plan view of areas of a surface compacted by passage of the compacting wheel when rolling over a substrate;
FIG. 3 is a schematic diagram showing (upper part) a rear view of a further compacting wheel and (lower part) a plan view of areas of a surface compacted by passage of the compacting wheel when rolling over a substrate;
FIG. 4 is an elevation of three-wheel embodiment of the invention;
FIG. 5 is an elevation of a two-wheel embodiment of the invention;
FIG. 6 is a view from below of the embodiment shown in FIG. 5 ;
FIG. 7 is a perspective view of the embodiment shown in FIG. 5 ;
FIG. 8 is a side view of the embodiment shown in FIG. 5 ;
FIG. 9 is an elevation of a five-wheel embodiment of the invention;
FIG. 10 is a cross-sectional view of the embodiment shown in FIG. 9 , the section being taken at the centre of a shaft mounting wheels of the device;
FIG. 11 is a perspective view of the embodiment shown in FIG. 9 , partially cut away;
FIG. 12 is a perspective view of a foot assembly of a compacting device according to the invention;
FIG. 13 is a view of the foot assembly shown in FIG. 12 , looking in the direction of arrow “A”;
FIG. 14 is a view of the foot assembly shown in FIG. 12 looking in the direction of arrow “B”;
FIG. 15 is a cross-sectional view of an alternative embodiment of a five-wheel compacting device according to the present invention;
FIG. 16 is an isolated perspective view of a mounting hub mounted to a wheel in accordance with the embodiment of the device shown in FIG. 15 ;
FIG. 17 is perspective view of the mounting hub of FIG. 16 ;
FIG. 18 is a plan view of the mounting hub of FIG. 17 ;
FIG. 19 is a plan view of the mounting hub of FIGS. 16 and 17 connecting adjacent wheels of a compacting device of the present invention;
FIG. 20 is a perspective view of a wheel of a compacting device in accordance with one embodiment of the present invention;
FIG. 21 is a perspective view of the wheel of FIG. 20 mounted to a shaft of a compacting device by way of a locating block in accordance with an embodiment of the present invention; and
FIGS. 22A-22C show perspective, plan and cross-sectional views of an embodiment of the locating block of FIG. 21 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a wheel-type compacting device 1 mounted on a backhoe excavator 2 and has been discussed above. The present invention provides an improved compacting device usable in the same way as compacting device 1 .
FIG. 2 shows a compacting device 20 such as that shown in the prior art device of FIG. 1 . In the upper part of FIG. 2 , a rear elevation of a compacting device 20 is shown, rolling on a substrate 21 . Device 20 comprises three wheels 22 , 23 and 24 , that are mounted on a single shaft (not shown) so as to rotate together rather than independently. The shaft is in turn supported for rotation in bearing assemblies 39 mounted to a pair of support members 38 located between wheels 22 and 23 , and 23 and 24 respectively. Wheel assemblies 22 , 23 and 24 each have compacting feet 29 whose outer surfaces 30 (all shown shaded) contact substrate 21 as the device 20 is rolled over the substrate 21 . No other constructional details of wheel assemblies 22 , 23 and 24 are shown. The lower part of FIG. 2 shows, in plan view, a portion of substrate 21 after the device 20 has been rolled over the substrate in a single rolling pass, with the areas 31 that are contacted by surfaces 30 indicated by shading.
It is apparent from FIG. 2 that a rolling pass of device 20 over substrate 21 provides compaction in three strips 32 , 33 and 34 , but does not directly compact substrate 21 in the two intervening strips 35 and 36 . These strips are not directly compacted by the device due to the support members 38 (similar to members 11 in FIG. 1 ) being provided between adjacent pairs of wheel assemblies 22 , 23 and 24 to support bearing assemblies 39 .
In practice, to compact the whole area of substrate 21 (which could be the floor of a trench) adequately and evenly, device 20 would need to be moved axially (i.e. in the direction of rotation axis 37 of device 20 ) from time to time and multiple rolling passes would need to be made at each axial position. This process also allows compaction to be carried out at the edges of a trench, despite the fact that the device 20 would in general be narrower than the trench width. As will be appreciated, in order to achieve effective soil compaction using such a process, significant operator skill and time is required.
According to the present invention, it has been found that, in at least some ground conditions, the performance of a device, such as device 20 , can be enhanced by making the individual feet on each wheel assembly narrower (in the axial direction) while maintaining the width of the strip contacted by each wheel assembly by offsetting some feet axially from others. One embodiment of such an arrangement is shown in FIG. 3 . In order to facilitate direct comparison of the device of the present invention as shown in FIG. 3 , and that of the prior art, as shown in FIG. 2 , the same item numbers with the suffix ‘a’ have been used for equivalent items. The effectiveness of the device 20 a , as shown in FIG. 3 , is thought to arise because the total area of the device 20 a in contact with the substrate 21 a is decreased, so leading to a higher level of compaction for a given downward force on the device 20 a . In successive passes of the device 20 a over the substrate 21 a , particularly if the device 20 a is lifted clear of the substrate 21 a at the end of each pass, the feet 29 a will not in general touch the substrate at identical positions as in previous passes, so that strips 32 a , 33 a and 34 a of the same width as strips 32 , 33 and 34 can be compacted, thereby providing improved compaction of the soil in these regions.
FIG. 4 shows a compacting device 40 in accordance with an embodiment of the present invention. The device 40 is shown as having three individual wheels 41 , 42 and 43 , each with feet 44 that are staggered in essentially the same way as the feet 29 a of the embodiment as shown in FIG. 3 . Wheels 41 - 43 are mounted to a single shaft (not shown) so as to rotate together as a unit, about a transverse axis 45 . Bearing assemblies 46 support the shaft and are themselves held by support members 47 . Support members 47 extend from a base 48 that is able to be secured (for example via a quick-hitch arrangement of known type, not shown) to an excavator stick in a similar manner to that shown for device 1 in FIG. 1 .
It will be appreciated that compacting devices according to the present invention may employ any number of individual wheels, and are not limited to having three wheels. Different numbers of individual wheels may be used to suit different work conditions, different trench widths and different supporting machinery. FIGS. 5 to 8 show a compacting device 50 having two wheels 51 and 52 and only one supporting member 53 positioned therebetween. Device 50 is otherwise similar to device 40 , especially in relation to the arrangement of the feet 54 provided on wheels 51 and 52 , and in this embodiment the wheels 51 and 52 also rotate together.
FIGS. 9 , 10 and 11 show another embodiment of a compacting device 60 according to the present invention. Device 60 has a total of five wheels, 61 , 62 , 63 , 64 and 65 , similar in their arrangement of feet 66 to wheels 41 - 43 of device 40 . Device 60 has only two support members 66 and 67 , having bearing assemblies 68 and 69 mounted respectively thereto. Support members 66 , 67 and bearing assemblies 68 , 69 are located between, firstly, wheels 62 and 63 , and, secondly, 63 and 64 . As can be seen in the sectional views of FIGS. 10 and 11 , wheels 62 , 63 and 64 are mounted to a single shaft 70 to rotate together. The outer wheels 61 and 65 are not mounted directly to shaft 70 but to hubs 71 and 72 , that are in turn bolted to wheel discs 73 and 74 respectively of wheels 62 and 64 . With this arrangement, outer wheels 61 and 65 are readily detachable so that device 60 is convertible to the narrower three-wheel device 40 , as required. This feature allows a narrow trench to be accommodated, or higher compaction with a given supporting machine weight, using three wheels 62 - 64 only when required or, alternatively, a wider trench can be accommodated using all five wheels 61 - 65 .
FIG. 15 shows an alternative embodiment of a compacting device 100 according to the present invention. As described the embodiment shown in FIGS. 9-11 , device 100 has a total of five wheels 101 - 105 . End wheels 101 and 105 are removable to enable the device 100 to be readily converted between a wide five-wheeled device and a narrow three-wheeled device, according to the requirements of the job to be performed. In this regard, device 100 also has two support members 106 , 107 having bearing assemblies 108 , 109 respectively mounted to an end thereof. A shaft 110 extends through the bearing assemblies 108 , 109 , and wheels 102 , 103 and 104 are mounted to the shaft 110 to rotate about the axis of the shaft 110 .
The end wheels 101 and 105 are respectively mounted to the shaft mounted wheels 102 and 104 by way of mounting hubs 115 . The mounting hubs 115 are mounted to the wheel discs of the wheels by appropriate bolts which allow ready attachment/detachment of the end wheels 101 and 105 , when required. This is shown in FIG. 16 wherein mounting hub 115 is mounted to the wheel disc 104 a of wheel 104 , in readiness to receive wheel 105 .
Mounting hub 115 is shown in more detail in FIGS. 17 and 18 and comprises a pair of mounting cups/discs 116 , 118 separated by a central core 117 . Each mounting cup/disc 116 , 118 is mounted to a wheel disc of the corresponding wheel pairs 104 / 105 and 101 / 102 such that rotation of the shaft mounted wheel 102 , 104 is transferred to the corresponding end wheel 101 , 105 . To facilitate mounting of the cups/discs 116 , 118 to the wheel discs, a plurality of holes 119 are formed around the periphery of each cup/disc to receive a fastener such as a bolt or the like. Holes 119 align with holes formed in the wheel discs of the wheels such that the fastener can pass through the wheel discs and cups 116 , 118 .
As shown more clearly in FIG. 18 , the holes 119 provided around the periphery of the cup/disc 116 are offset with respect to corresponding holes 119 provided around the periphery of cup/disc 118 . In the embodiment as shown the corresponding holes 119 are offset an angle θ with respect to the central axis of the mounting hub 118 . This offset angle θ is preferably between around 10° and 20°, more preferably 15°.
Such an offset angle between corresponding holes 119 formed in the periphery of the cups/discs 116 , 118 , ensures that when wheels 101 / 102 and wheels 104 / 105 are mounted together by way of the mounting hub 115 , the contacting feet of adjacent wheels are arranged in a circumferentially staggered manner. As discussed above, such a circumferentially staggered arrangement of contacting feet between adjacent wheels aids in facilitating improved soil compaction as the device 100 is rolled over the soil surface in multiple passes.
This circumferential staggered arrangement of the contacting feet of adjacent wheels can be seen more clearly in the isolated view of FIG. 19 . As shown, end wheel 105 is mounted to wheel 104 by way of mounting hub 115 in the manner as discussed above. When mounted in this manner, the contacting feet 120 a of end wheel 105 are circumferentially offset with respect to the contacting feet 120 b of wheel 104 . In this regard, when the device 100 is rolled over the soil to be compacted such that the adjacent wheels rotate together, the corresponding feet 120 a and 120 b on adjacent wheels do not contact and pass over the soil at the same time. This avoids the formation of a common path or plane of soil compaction extending orthogonal to the direction in which the device travels, which can cause corrugation in the compacted soil and inconsistent compaction.
One embodiment of the construction of the wheels of the compacting devices according to the present invention will now be described. This construction can be best seen in the sectioned views of FIGS. 10 and 11 that show wheels 61 - 65 . However, it is to be understood that essentially the same construction can be used in the wheels 41 - 43 of device 40 , wheels 51 , 52 of device 50 , and wheels 101 - 105 of device 100 .
Wheel 64 will be described by way of illustration. Wheel 64 has a hub 80 that is secured (by any suitable means known in the art such as a key or pin, not shown) to shaft 70 . A wheel disc 74 is then secured to hub 80 . This could be achieved by welding or bolting the wheel disc 74 to the hub 80 or by any other suitable manner known in the art. Alternatively, hub 80 and wheel disc 74 could be integrally formed, for example by casting. Secured to the outer edge of wheel disc 74 are foot assemblies 82 , each of which includes two feet 66 . The feet 66 of each foot assembly 82 are offset from each other in an axial direction (i.e. a direction parallel to shaft 70 in device 60 ). FIGS. 12 , 13 and 14 show one embodiment of the foot assembly 82 .
Foot assembly 82 is advantageously a single casting and has a base 83 that connects feet 66 and has an arc that which generally conforms to the arc of the circumference of the wheel disc 74 . Formed within base 83 is a groove 84 that is shaped and sized to snugly receive an outer peripheral part of wheel disc 74 . Foot assembly 82 can be secured to wheel disc 74 by positioning it on disc 74 so that the disc 74 is received in groove 84 with the outer circumferential edge of disc 74 abutting surface 85 of groove 84 , and then welding assembly 82 to disc 74 . This process is repeated for each of the assemblies 82 required to be secured around the periphery of wheel disc 74 . Assembly 82 is shown in use in devices 40 , 50 and 60 .
It will be apparent to persons skilled in the art that, as an alternative, an assembly similar to assembly 82 , namely having two offset feet 66 , could be made that would be able to be secured to wheel disc 74 by bolting therethrough or by pinning, rather than welding. The assemblies 82 may also be formed integral with the wheel disc 74 , by casting or other such methods. It will also be apparent that different numbers of feet than the two feet 66 could be incorporated in an alternative design of foot assembly (not shown) if required.
It will also be apparent that if the depth of groove 84 is suitably chosen, a foot assembly such as assembly 82 could be mounted to a range of diameters of wheel disc 74 .
An alternative wheel construction is shown in FIG. 20 as wheel 120 . Wheel 120 is cast as a single unit and includes an integral hub 122 that is adapted to be secured to a shaft of the device in a manner discussed below. A wheel disc 125 is formed about the hub 122 and has a plurality of holes 126 formed therethrough for mounting a mounting hub 115 in the manner as described above. A plurality of radial spoke elements 127 extend from the wheel disc 125 and hub 122 and terminate in an external rim 128 . A plurality of contacting feet 129 extend from the outer surface of the rim 28 , and each of the feet 129 are offset from each other in an axial direction (i.e. in a direction parallel to a shaft extending through the hub 122 ). The feet 129 function in the same manner as the feet 66 discussed above and have the same general shape characteristics.
The hub 122 has a pair of opposing recess portions 124 formed therein to facilitate mounting of the wheel 120 to a shaft 123 . As shown in FIG. 21 , each recess portion 124 is shaped to receive a locating block 130 . The locating block 130 is shown in more detail in FIGS. 22A-22C and is generally in the form of a wedge or insert having a head portion 132 and a body portion 134 . The body portion 134 is shaped to fit into the recess portion 124 such that the distal end of the body portion 134 abuts the shaft 123 , as shown in FIG. 21 . The head portion 122 is shaped to abut the surface of the hub 122 and has a pair of V-shaped wings 131 which are snugly received in a pair of V-shaped grooves formed in the surface of the hub 122 . Such an arrangement provides a snug fit between the locating block 130 and the hub 122 , such that the locating block 130 is able to be simply aligned into the recess portion 124 .
In order to secure the wheels 120 to the shaft 123 , holes 123 a are provided through the shaft 123 , as shown in FIG. 21 . The holes 123 a are provided at desired positions along the length of the shaft 123 and orientated in the same manner, for ease of construction. As shown in FIG. 22C , each locating block 130 has a hole 135 formed therethrough.
To assemble the device, the wheels 120 are positioned on the shaft 123 and the locating blocks are inserted into the recess portions 122 such that the hole 135 formed in the locating blocks aligns with the hole 123 a formed in the shaft 123 . A suitable pin or key may then be inserted through the aligned holes 135 and 123 a to secure the wheel 120 in position on the shaft 123 .
Such an arrangement overcomes the need to drill precise holes through the hub 122 , which can be difficult due to the orientation and size of the hub 122 and the tolerances required. Further, in order to orientate adjacent wheels 120 of the device such that the feet 129 of adjacent wheels 120 are arranged in a circumferentially staggered manner, it would be necessary to drill holes through the hub at different positions for each wheel 120 , such that when the wheels are secured to the shaft 123 they are correctly orientated with respect to neighbouring wheels.
By employing the locating blocks 130 of the present invention adjacent wheels can be relatively easily positioned and secured in place such that the contacting feet 29 of adjacent wheels are circumferentially staggered, in the manner as shown in FIG. 19 . This is achieved through forming the holes 135 in the locating block 130 at an angle β to the vertical axis, as shown in FIG. 22C . Such an orientation of the holes 135 provides a relatively simple way in which to control the orientation of adjacent wheels 120 when secured to the shaft 123 . The angle β can vary to provide a variety of circumferentially staggered arrangements. In a preferred form, in order to ensure that there is a constant 150 stagger between wheels, the angle β may be 7.5°. Therefore by inserting the locating blocks 130 within the recess portion 124 of the hubs 122 of adjacent wheels in opposite orientations, adjacent wheels 120 will have their contacting feet 129 circumferentially staggered by 15°. Such an arrangement enables a single type of wheel 120 and locating block 130 to be supplied for assembling the compacting devices to a variety of needs.
Plain bearings may be used to mount devices such as 40 , 50 , 60 , 100 , and 120 to their support members 47 , 53 , 66 , 67 , 106 , and 107 . These may use suitable plastics bushes. Alternatively, rolling element bearings may be used.
Although for each of the devices 40 , 50 , 60 , 100 and 120 the wheels 41 - 42 , 51 - 53 , 61 - 65 , and 101 - 105 have been described as rotating together, it is possible as an alternative to arrange for some or all of the wheels to be allowed to rotate separately.
The present invention provides various embodiments of a soil compacting device that can be readily attachable to a variety of machines to achieve improved soil compaction through greater distribution of soil compacting forces to the soil being compacted. The devices are constructed in a manner that enables the compacting wheels to be relatively easily attached/detached from the device. This facilitates conversion of the device between a narrow device suitable for compacting narrow soil regions, and a wider device suitable for compacting larger surface areas, depending on the type and nature of the task to be performed.
It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. | A compacting device ( 40 ) for attachment to an earthmoving machine ( 2 ) to compact a substrate is described. The compacting device ( 40 ) includes a plurality of wheel assemblies ( 41, 42, 43 ) mounted for rotation in bearings ( 46 ). A support is also provided, having a base part ( 48 ) that is adapted to be mounted to the earthmoving machine ( 2 ). One or more bearing support members ( 47 ) extend from the base part ( 48 ) and between the wheel assemblies ( 41, 42, 43 ) to support the bearings ( 46 ). Each wheel assembly ( 41, 42, 43 ) includes a set of ground-contacting feet ( 44 ) secured to and peripherally spaced apart around a rim portion of the wheel assembly ( 41, 42, 43 ). In this arrangement, when the device ( 40 ) is rolled over the substrate a first foot of said set of ground engaging feet ( 44 ) contacts the substrate between axial width limits that differ from axial width limits of a second foot of said set of ground engaging feet ( 44 ). | 4 |
RELATED APPLICATION
This application is a continuation in part of application Ser. No. 09/483,899 filed Jan. 18, 2000 now U.S. Pat. No. 6,372,934 B1.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound, which is cationic with an anionic compound, producing a salt-complex, and an inorganic salt. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
2. Arts and Practices
Fatty quaternary compounds commonly called quats, are tetra-substituted ammonium compounds where each of the four groups on nitrogen are a group other than hydrogen. If any hydrogen groups are present, the compounds are not quaternary amines, but rather are primary or secondary amines.
The most commonly encountered substituents are alkyl and alkyl amido groups. There are several classes of quats. The most important are (a) alkyl tri methyl quats for example cetyltrimonium chloride, (b) alkylamidopropyl dimethyl quats like stearylamidoalkonium chloride and (c) di alkyl, di methyl quats for example dicetyldimonium chloride and (d) alkyl, benzyl, Di methyl quats like stearalkonium chloride.
There are several undesirable attributes of fatty cationic products.
1. Fatty Quaternary compounds are incompatible with anionic surfactants since an insoluble complex frequently is formed when the two types of materials are combined.
2. Many fatty Quaternary Compounds are eye irritants. The material is minim ally irritating to the eyes at concentrations of 2.5%, which limits the concentration, which is useful if low irritation is a requirement.
3. Fatty quats are generally hydrophobic and when applied to substrate can cause a loss of absorbance of the substrate. It is not an uncommon situation for a traveler to a hotel to encounter a very soft towel that totally fails to absorb water. This is because the fatty quaternary gives softness but being hydrophobic also prevents re-wet. This situation also can be observed on hair, the conditioner becomes gunky on the hair and has a tendency to build up.
We have learned that making complexes of cationic compounds (the so-called quaternary compounds) with carboxy fatty alcohol alkoxylates can unexpectantly mitigate many of these negative attributes. The preferred complex has to have a molecular weight of over 1000 molecular weight units to obtain the most effective irritation mitigation. The mitigation of irritation, the improved water solubility and the skin feel make the compounds of the present invention highly desirable in personal care applications. Combining these complexes with dimethicone copolyol polymers, produces products having low eye irritation, good skin feel and good emolliency. This makes the compounds ideally suited for ultra mild applications like baby shampoo and bubble bath applications.
THE INVENTION
Object of the Invention
It is the object of the present invention to provide a series of novel salt complexes that are made by neutralizing a fatty ammonium compound, which is cationic with an anionic compound, producing a salt-complex. The preferred complex has a molecular weight above 1000 molecular weight units. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications, where low irritation is required.
An additional objective of the invention is to provide a process for conditioning hair and skin which comprises contacting the hair or skin with an effective conditioning concentration of the complex. The effective conditioning concentration is between 0.1 and 25% by weight of the formulation.
SUMMARY OF THE INVENTION
The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound, which is cationic with an anionic compound, producing a salt complex having a molecular weight above 1000 molecular weight units. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the present invention conform to the following structure:
wherein;
R 1 is CH 3 —(CH 2 ) n —O—(CH 2 CH 2 O) a —(CH 2 CH(CH 3 )O) b —(CH 2 CH 2 O) c —;
n is an integers ranging from 7 to 21;
a and c are integers independently ranging from 0 to 20,
b is an integer ranging from 0 to 20;
R 3 is selected from the group consisting of CH 3 (CH 2 ) e — and
R 5 —C(O)N(H)—(CH 2 ) 3 —
R 5 is CH 3 (CH 2 ) f —
e is an integer from 5 to 21;
f is an integer from 5 to 21,
R 4 is selected from the group consisting of CH 3 (CH 2 ) g
g is an integer ranging from 0 to 21 and
The invention is also directed to a process for conditioning hair and skin which comprises contacting the hair or skin with an effective conditioning concentration of a complex conforming to the following structure;
wherein;
R 1 is CH 3 —(CH 2 ) n —O—(CH 2 CH 2 O) a —(CH 2 CH(CH 3 )O) b —(CH 2 CH 2 O) c —;
n is an integers ranging from 7 to 21;
a and c are integers independently ranging from 0 to 20;
b is an integer ranging from 0 to 20,
R 3 is selected from the group consisting of CH 3 (CH 2 ) e — and
R 5 —C(O)N(H)—(CH 2 ) 3 —
R 5 is CH 3 (CH 2 ) f —
e is an integer from 5 to 21;
f is an integer from 5 to 21;
R 4 is selected from the group consisting of CH 3 (CH 2 ) g
g is an integer ranging from 0 to 21 and
Preferred Embodiment
In a preferred embodiment R 1 is;
CH 3 —(CH 2 ) n —O—(CH 2 CH 2 O) a —(CH 2 CH(CH 3 )O) b —(CH 2 CH 2 O) c —
In a preferred embodiment e is an integer ranging from 7 to 21.
In a preferred embodiment R 3 is;
R 5 C(O)N(H)—(CH 2 ) 3 —
f is an integer ranging from 5 to 21.
In a preferred embodiment R 4 is methyl.
In a preferred embodiment R 4 is
In a preferered embodiment the molecular weight of the complex is greater than 1000 daltons.
In another preferred embodiment, the complex is blended with dimethicone copolyol to improve the skin feel.
Examples of Reactants
Alcohol Alkoxy Carboxylate
The reaction sequence is illustrated by the reaction of an alcohol alkoxylate with sodium mono-chloroacetate:
R 1 OH+Cl—CH 2 C(O)O − Na + →R 1 O—CH 2 C(O)O − Na +
R 1 O—CH 2 C(O)O − Na + +H + →R 1 O—CH 2 C(O)OH
R 1 O—CH 2 C(O)OH is the raw material useful in the preparation of the complexes of the present invention. The water can be removed by distillation and the salt filtered off.
Raw Materials
Carboxylates suitable for the preparation of the compounds of the present invention are commercially available from a variety of sources including Siltech Corporation in Toronto Ontario Canada.
Example
n
a
b
c
1
8
0
0
0
2
10
0
1
12
3
12
20
10
20
4
14
3
1
3
5
16
20
20
20
6
18
12
0
0
7
20
12
1
1
8
22
5
0
5
Cationic Examples
The cationic compounds of the present invention are commercially available from a variety of sources including Croda Inc. and Siltech Corporation. They conform to the following structure:
wherein;
R 3 is selected from the group consisting of
CH 3 (CH 2 ) e —
and
R 3 —C(O)N(H)—(CH 2 ) 3 —
R 5 is CH 3 (CH 2 ) f —
e is an integer from 5 to 21;
f is an integer from 5 to 21;
R4 is selected from the group consisting of CH 3 (CH 2 ) g
g is an integer ranging from 0 to 21 and
the group consisting of Cl − , Br − , and CH 3 SO 4 − .
As used herein
EXAMPLES
Class 1
Cationic Compounds
Example
e
g
9
7
0
10
11
0
11
17
0
12
17
0
13
21
0
14
21
benzyl
M is Cl −
Class 2
Cationic Compounds
Example
e
g
15
7
7
16
11
7
17
15
21
18
17
3
19
21
5
20
17
benzyl
21
21
benzyl
M is Cl −
Class 3
Cationic Compounds
R 3 is R 5 C(O)N(H)—(CH 2 ) 3 —
Example
f
g
22
7
0
23
9
0
24
11
0
25
17
11
26
21
21
27
17
Benzyl
28
5
11
M is Cl −
Complexation
The carboxylate (examples 1-8) and the cationic compound (examples 9-28) are blended into water to make up a concentration of between 20-70% by weight. The preferred range is 30-50% by weight. The pH of the resulting mixture is then adjusted to between 5 and 9. The lower pH is preferred for skin care products, the higher for hair care products. The complex forms in aqueous solution and the counter ion on the cationic material remains in the solution as inorganic salt.
Example 29
To a suitable vessel is added 840.0 grams of water. Next 491.0 grams of carboxy compound Example 1 is added under agitation. Next 209.0 grams of cationic compound 9 is added. The pH is adjusted to 7.0 with KOH. The complex is used as prepared.
Examples 30-45
Example 29 is repeated, only this time the specified amount of water. Next the specified amount of the specified anionic compound is added. Next the specified amount of the specified cationic compound is added. The pH is adjusted to 7.0 with KOH. The complex is used as prepared.
Anionic Compound
Cationic Compound
Water
Example
Example
Grams
Example
Grams
Grams
30
2
842.0
9
265.0
1328.0
31
3
2633.0
10
349.0
3578.0
32
4
547.0
11
373.0
1104.0
33
5
3279.0
12
405.0
4420.0
34
6
895.0
13
416.0
1704.0
35
7
1026.0
14
293.0
1582.0
36
8
863.0
15
349.0
1515.0
37
1
489.0
16
601.0
1635.0
38
2
840.0
17
377.0
1292.0
39
3
2631.0
18
416.0
3656.0
40
4
545.0
19
389.0
1167.0
41
5
3277.0
20
445.0
4466.0
42
6
893.0
21
280.0
1257.0
43
7
1024.0
22
308.0
1600.0
44
8
861.0
23
336.0
1436.0
45
5
3277.0
24
445.0
4466.0
46
6
893.0
25
280.0
1257.0
47
7
1024.0
26
308.0
1600.0
48
8
861.0
27
336.0
1436.0
Applications Evaluation
Control Compounds
Stearalkonium Chloride is an excellent conditioning agent, having outstanding substantivity to hair. It has detangling properties, improves wet comb when applied after shampooing. The FDA formulation data for 1976 reports the use of this material in 78 hair conditioners, eight at less than 0.1%, eighteen at between 0.1 and 1.0% and 52 at between 1 and 5%.
Cetyltrimonium Chloride, or CTAC, is a very substantive conditioner which in addition having a non-greasy feel, improves wet comb and also provides a gloss to the hair. It is classified as a severe primary eye irritant. 18 Therefore its use concentration is generally at or below 1%.
Eye Irritation
Eye irritation is a major concern in the formulation of personal care products, when working with quats. Primary eye irritation was tested using the protocol outlined in FHSLA 16 CFR 1500.42. The products were tested at 25% actives. The results were as follows:
Cationic Compounds (Not of the Present Invention)
Product
Score
Result
Stearalkonium Chloride
116.5
Severely Irritating
Cetyltrimethyl ammonium Chloride
106.0
Severely Irritating
Cetyltriethyl ammonium Chloride
115.0
Severely Irritating
Complexes of the Present Invention
Product
Score
Result
Example 30
8.1
Minimally Irritating
Example 31
11.3
Minimally Irritating
Example 42
10.2
Minimally Irritating
Example 45
4.9
Minimally Irritating
Example 46
7.8
Minimally Irritating
As the data clearly shows, the irritation potential of the complex is dramatically reduced, when compared to the starting quat.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth hereinabove but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains. | The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound which is cationic with an anionic compound, producing a salt complex. The compounds of the present invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improvement in indirect/direct evaporative cooling devices, and particularly to indirect/direct evaporative cooling devices used in conditioning air for comfort purposes.
2. Description of Related Art
Two stage evaporative coolers offer great promise for satisfying residential cooling loads at lower cost and with reduced environmental impacts compared to conventional air conditioning systems. Two stage coolers include an "indirect" stage and a "direct" stage and are also known as indirect/direct evaporative cooling (IDEC) units. IDEC units provide cooling with much less addition of moisture to the indoor space than direct evaporative coolers. In drier climates, most conventional (vapor-compression cycle) air conditioning systems use energy unnecessarily to remove moisture from indoor spaces.
In the first, i.e. indirect, stage of the IDEC unit, outdoor air is cooled without adding moisture. Indirect cooling is typically accomplished by passing the air through a first set of alternating passages in a system of parallel heat exchange plates. Simultaneously, a second airstream is passed through the second set of alternating passages. Water is supplied to the surfaces of the heat exchange plates that form the second set of passages. The second airstream contacts the wet heat exchange plates and evaporatively cools the plates. The first airstream is cooled by contact with the surfaces of the cooled plate. The cooled first airstream exits the indirect evaporative cooling stage and is then further evaporatively cooled by direct contact with a wet medium in the direct evaporative cooling stage. The first airstream exits the direct cooling stage where it is then supplied to the interior of a building. While it is theoretically possible to cool the supply air completely by an indirect process, the cost of larger plates and greater "wet passage" air quantities limits the potential cost-effectiveness of "indirect-only" coolers.
Several IDEC systems are currently available for commercial building applications. Only one, the "MasterCool 2 Stage" unit produced by AdobeAir of Phoenix, Ariz., is currently marketed for residential applications. "MasterCool 2 Stage" units have been successfully used in many homes. Extensive monitoring data and occupant responses testify to the effective performance of these units. However, these units are somewhat larger than conventional cooling systems. Consequently, the potential for retrofit installations is limited.
In addition, the on/off operation of the blowers of the conventional IDEC systems produces noticeable noise during operation. Consequently, the user is always aware of unit operation.
Moreover, the conventional IDEC systems have the indirect and direct stages formed as independent units that are connected together to form the IDEC unit. Such an arrangement leads to redundancies in the components of the indirect and direct cooling stages. For example, the conventional IDEC systems have separate pumps and blowers for each of the cooling stages. Consequently, such systems are large and expensive.
In addition, the sump of conventional IDEC systems is conducive to bacterial growth which can lead to odors and possible health hazards, because the conventional sump maintains a constant water level. Bacterial growth is fostered by permitting the water to remain in the sump for an extended period of time, particularly during warm weather.
Further, in order to supply the cooled air from the IDEC unit through an exterior wall of the building, it is frequently necessary to modify the wood framing arrangement of the wall. As a result, installation costs are significantly increased.
For these reasons, there exists a need for an indirect/direct evaporative cooling unit that is compact and can be easily retrofitted to existing residences. In addition, there exists a need for an indirect/direct evaporative cooling unit that minimizes awareness of unit operation. There also exists a need for an indirect/direct evaporative cooling unit that can be easily fabricated with a minimum number of components.
SUMMARY OF THE INVENTION
The present invention is directed to an indirect/direct evaporative cooling unit that satisfies these needs. An indirect/direct evaporative cooling unit having features of the present invention includes an indirect evaporative cooling stage, a direct evaporative cooling stage positioned downstream with respect to the indirect evaporative cooling stage, and a vertically discharging blower positioned upstream with respect to the indirect evaporative cooling stage. The indirect evaporative cooling stage has a substantially horizontally extending first flow passage and a substantially vertically extending second flow passage. With this arrangement, the indirect/direct evaporative cooling unit has a compact footprint. As a result, retrofit installation in existing residences is facilitated.
In accordance with another embodiment of the invention, the indirect/direct evaporative cooling unit uses a single blower. With this arrangement, the overall size and cost of the cooling unit is reduced since the use of separate blowers for the indirect and direct cooling stages is eliminated.
In accordance with another embodiment of the invention, the blower is a variable speed blower. With this arrangement, the blower can gradually increase and decrease speeds. As a result, awareness of unit operation is minimized, and average energy efficiency is improved since the blower can be driven at the lowest speed required by the current cooling load.
In accordance with another embodiment of the invention, a common sump and pump for water collection and recirculation is provided for both the direct and indirect evaporative cooling stages. With this arrangement, the indirect/direct evaporative cooling unit can be made more compact, manufacturing is simplified, and cost is reduced.
In accordance with a still further embodiment of the invention, the sump of the indirect/direct evaporative cooling unit is provided with a controlled dump valve to regularly and completely drain the sump water. Accordingly, bacterial growth can be inhibited.
In accordance with another embodiment, the sump is further provided with sloped walls to ensure complete drainage of the water contained in the sump.
In accordance with another embodiment of the invention, the indirect/direct evaporative cooling unit is provided with a stud-straddle supply duct. With this arrangement, modification of the existing wall stud arrangement is eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein:
FIG. 1 is a side cross-sectional view of the indirect/direct evaporative cooling unit according to an embodiment of the present invention;
FIG. 2 is a partial cross-sectional view of the heat exchange plate arrangement of the indirect cooling stage shown in FIG. 1;
FIG. 3 is an enlarged, side cross-sectional view of a drip edge shown in FIG. 1;
FIG. 4 is a perspective view of a stud-straddle supply duct for use with the indirect/direct evaporative cooling unit of FIG. 1;
FIG. 5 is a schematic diagram of a sump arrangement according to another embodiment of the invention; and
FIG. 6 is a side cross-sectional view of an indirect/direct evaporating cooling unit using an alternative heat exchange plate arrangement.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A preferred embodiment of the present invention is described hereafter, with reference to the drawings.
FIG. 1 is a side cross-sectional view of the indirect/direct evaporative cooling (IDEC) unit according to an embodiment of the present invention.
The IDEC unit 1 includes a housing 2. Louvers 3, formed in both sides of the housing 2, permit communication between an intake of a blower 4 and outside air. The blower 4 operates at variable speeds and may include, for example, an impeller wheel operably connected to a variable speed motor. The variable speed operation of the blower improves average energy efficiency of the IDEC unit by operating at the lowest speed required by the current cooling load. The blower is driven by an electronically commutated motor (ECM) having an efficient operation throughout a wide range of speeds so as to gradually increase and decrease speed. The gradual changes in the speed of the blower minimize awareness of unit operation.
The air is discharged by the blower vertically through an outlet 5 of the blower. A portion 7b of the air flow is diverted from a first air flow 7a by a diverter 6. First air flow 7a, which will eventually be supplied to the interior of the building, is first redirected to flow horizontally by turning vanes 8. The redirected first air flow 7a then enters an indirect evaporative cooling stage 10, where it is cooled without the addition of moisture thereto (to be later described). The cooled first air flow 7a leaves the indirect cooling stage and enters the direct cooling stage 11, where it is further evaporatively cooled prior to being supplied to the interior of the building.
The second air flow 7b, which serves to cool the first air flow (as described later), is directed to the bottom of the indirect cooling stage 10 by a perforated baffle 9. The second air flow 7b enters the bottom of the indirect cooling stage, flows vertically through the indirect cooling stage, and then exits through a grill 14 into the atmosphere.
A sump 17 is positioned beneath both the direct and indirect cooling stages to catch drain water from these cooling stages. The sump 17 has a sloping wall 17a to facilitate water drainage. A pump 17b having an inlet connected to the floor of the sump 17 is provided to pump the accumulated drain water to an indirect stage top tray 16 and a direct stage feed tube 16a. From the top tray 16, water is conveyed by felt strips rub 18 downward into the top portion of the indirect cooling stage wet passages.
FIG. 2 is a partial cross-sectional view of the heat exchange plate arrangement of the indirect cooling stage 10 shown in FIG. 1. The indirect cooling stage 10 uses parallel heat exchange plates 20. The plate designed is substantially as shown in U.S. Pat. Nos. 4,461,733 and 4,566,290, the disclosures of which are hereby incorporated by reference. As shown in FIG. 2, the indirect cooling stage is divided into a first set of passages 21 for first air flow 7a, and a second set of passages 22 for second air flow 7b. Passages 22 are treated to enhance wettability. Water, conveyed by siphoning action through tubes 18, enters the second set of passages 22 and wets the surfaces of the heat exchange plates. Second air flow 7b flows through the second set of passages 22 and evaporatively cools the heat exchange plates 20. Meanwhile, the first air flow 7a, traveling through the first set of passages 21, is cooled by contact with the surfaces of the cooled heat exchange plates. In this manner, the first air flow is cooled without the addition of any moisture thereto.
The cooled first air flow 7a leaves the indirect cooling stage and is further cooled in the direct cooling stage 11 in a known manner. The direct evaporative cooling stage 11 includes an evaporative medium 12 (FIG. 1) which includes, for example, a wetted pad or permeable medium, to evaporatively cool the first air flow 7a. A suitable high quality evaporative medium is "CELDEC," available from Munters Corporation.
As shown in FIG. 3, one end of the bottom portion 10a of the indirect evaporative cooling stage 10 rests on a linear drip edge 30. Any indirect stage drain water that escapes from the indirect cooling stage 10 due to, for example, turbulence, will enter passage 31 formed by the upper end of the bottom portion 10a and the upper portion 30a of drip edge 30. The drain water is directed to the sump 17 through the perforations of baffle 9 by the bottom portion 30b of the drip edge 30.
With the above arrangement, any drain water that escapes from the indirect cooling stage 11 is kept out of the first air stream 7a and the blower 4. Further, the perforated baffle 9 smooths the entry of second airflow 7b into the vertical passages of indirect stage 11 while permitting drain water to pass therethrough.
FIG. 4 is a perspective view of a stud-straddle supply duct 40 for use with the IDEC unit 1 of FIG. 1 The rear portion 41 is connected to the IDEC unit 1 by a rolled edge 42 cooperatively engaging a corresponding mating portion on the IDEC unit (not shown). A front portion 43 includes two supply air outlets 44 for discharging the cooled air into the building. The outlets 44 are separated from each other by a channel 45, which is sized to receive a wall stud (not shown) in the exterior wall of the building. Typically, the wall studs are either 2"×4" or 2"×6" lumber spaced on 16" centers. When 2"×4" studs are used, distances A and B preferably equal about 4" and 7", respectively. When 2"×6" studs are used, A and B preferably equal about 6" and 9", respectively. C preferably equals about 1" with both stud sizes. With the above arrangement, modification of the existing wall stud arrangement is eliminated. It is understood, of course, that other dimensions are possible. Such other dimensions are limited only by the object of eliminating the need to modify the existing stud arrangement of the wall. A single grille may be used on the interior side to cover the two outlets and to direct air flow as desired.
FIG. 5 illustrates an alternative sump arrangement for use with the IDEC unit. This embodiment is designed to prevent continuous standing water in the sump and thus prevent bacterial growth in the sump.
In FIG. 5, sump 17 has a long sloping side 17a and a narrow bottom 17c which also slopes toward a combined drain and pump suction port 58. When the sump is dry and operation of the IDEC unit is anticipated by the system controller 100, a motorized drain valve 59 is closed and a motorized fill valve 51 is opened by the controller to allow water from a pressurized supply 52 to enter the sump pan through a fill port 50. Fill port 50 is located higher than an overflow port 56 connected to drain pipe 60. By providing the overflow port, even if the fill function should malfunction (for example, by valve fill 51 sticking in the open position), the sump will not overfill or allow backflow through supply port 50 to contaminate the public water supply. Filling continues until a float 53 is sufficiently lifted by the rising water level so as to signal the fill valve 51 to close. A second float 54 is provided to protect pump 17b from running dry.
When the system thermostat 101 indicates a cooling load, pump 17b is started only when float 54, which is located at a level lower than float 53, is raised to a predetermined position by the water in the sump. Blower 4 (FIG. 1) begins operation a short time later, i.e., after a period of time that is sufficient to allow pump 17b to suitably wet the evaporative media has elapsed. Pump 17b draws sump water from port 58 through a screen 57 provided to prevent debris from entering the port. When the cooling cycle terminates, the pump and blower are deactivated and drain water returns to the sump.
When the system has been off for an extended period of time, e.g., three hours, as measured by the system controller 100, the motorized drain valve 59 is automatically opened and the water in the sump is completely drained through drain pipe 60. During drainage, the float 53 will fall below its predetermined water fill signalling height. Therefore, in order to permit the sump to dry, fill valve 51 is controlled so as to remain closed regardless of the position of float 53 during drainage. The fill valve 51 remains closed until the system thermostat signals a cooling load.
With the above arrangement, since the water in the sump is regularly and completely drained, bacterial growth in the sump is prevented.
Further, removal of the sump water facilitates drying of the evaporative media which in turn impedes bacterial growth on the media, because removal of the sump water reduces the humidity inside the IDEC unit. In typical dry climate conditions, the evaporative media will completely dry at least once per day using the embodiment of FIG. 5.
FIG. 6 illustrates an IDEC unit 1' which uses an alternative heat exchange plate arrangement for the indirect cooling stage 10' than that of the previously described embodiment of FIG. 1. In the embodiment of FIG. 6, the horizontally extending passages 21 of the heat exchange plates have lengths that increase in the vertical direction so as to form a heat exchange plate assembly having a substantially trapezoidal cross-section. The horizontal walls of the passages 21 formed by the fins 23 (FIG. 2) have downwardly curved portions 23a that redirect the vertical primary flow 7a to the horizontal direction. Thus, the downwardly curved portions 23a perform the same function as the previously described turning vanes 8. The downwardly curved portions 23a are molded onto the heat exchange plates as a one-piece unit.
With this arrangement, the separately formed and assembled turning vanes 8 of the first described embodiment are not needed. Consequently, assembly is simplified and cost is reduced. Further, the trapezoidal configuration of the indirect cooling stage results in a smaller footprint than that of the first embodiment, by eliminating the extra space required for turning vanes 8. Consequently, the dimension of the IDEC along the horizontal flow direction may be reduced.
Although the invention has been shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. | An indirect/direct evaporative cooling system for cooling air for comfort purposes includes a single, variable speed blower positioned below an indirect evaporative cooling stage and a direct evaporative cooling stage. A first portion of the blower discharge is directed horizontally through the indirect evaporative cooling stage, where it is cooled without the addition of moisture thereto, and is then further cooled in the direct evaporative stage prior to being supplied to a building. A second portion of the blower discharge is directed vertically through the indirect evaporative cooling stage and serves to cool the first portion as the first portion travels through the indirect stage. The indirect and direct cooling stages share a common sump for collecting water drained therefrom. The indirect stage includes a drip edge to keep drain water out of the flow of the first portion. A stud-straddle supply duct is attached to the direct cooling stage to facilitate installation of the system in wood-framed walls. | 5 |
This is a continuation of application Ser. No. 07/912,171, filed on Jul. 13, 1992 now U.S. Pat. No. 5,296,013.
BACKGROUND OF THE INVENTION
The invention relates to a process and an apparatus for continuous production of nonwovens, particularly mineral wool nonwovens.
In the production of mineral wool nonwovens, e.g. from rock wool or glass wool, not only is the fiberisation process of importance, but also the formation of the nonwoven fabric as such constitutes an important process step. It is customary in this respect for a fibre/gas/air mixture produced by a fiberisation unit to be introduced into a box-like so-called chute to separate the fibres, which chute usually features at the bottom an accumulating conveyor acting as a type of filter screen which is constructed in the form of a gas-permeable, rotating, plane conveyor belt. Under the conveyor belt is located an extraction device which generates a certain partial vacuum. In addition, drum-shaped accumulating conveyors with curved suction surfaces are also known from, for example, German patent specification DE-PS 39 21 399.
If the fibre/gas/air mixture--which can also contain a binder--impinges on the accumulating conveyor, the gas/air mixture is sucked through to below the accumulating conveyor acting as a filter, and the fibres are retained on the conveyor in the form of a nonwoven fabric.
In the known process for nonwoven fabric production, there are generally a plurality of adjacently arranged fiberisation units which produce fibre flows in a manner familiar to a person knowledgeable in the art. For the sake of simplicity, the term "fibre flow" or "fibre stream" used in the following shall refer to the flow bundle comprising fibres, process air, and binder where appropriate, with the term "process air" also covering the propellant gas required in order to draw out the fibres, the secondary air entrained during fiberisation, and any false air which may be sucked into the process for the purpose of cooling following fibre drawing.
Into the space bounded by the accumulating conveyor and the side walls of the chute, are thus introduced from the top fibre flows arranged in the form of adjacent core streams which carry fibres which are in the process of production or which have just been produced. In order to facilitate a directed flow and orderly deposition of the fibres as a nonwoven fabric on the accumulating conveyor, it is therefore necessary to extract the introduced process air from below the accumulating conveyor. By this means, one obtains in the chute a vertical stream of the fibre flows, from which the fibre content is trapped at the accumulating conveyor, as if at a filter, to form a nonwoven fabric which is then conveyed away while the process air continues to flow to extraction devices.
The extraction process under and in the accumulating conveyor presents certain difficulties as extraction has to be performed through the forming wool nonwoven, so that at the beginning of nonwoven formation there is, of necessity, less flow resistance while after partially completed nonwoven formation, a greater level of flow resistance has to be overcome. Directly above the nonwoven formation zone, therefore, a non-uniform flow pattern prevails owing to the spatially differing thicknesses of the nonwoven fabric lying below.
At the entry end of the chute, i.e. above the nonwoven formation zone, the fibre flow pattern is made up of a plurality of core streams, with each core stream initially being readily assignable to an individual fiberisation unit. The core streams which occur immediately below the fiberisation units, which core streams exhibit the energy of the propellant gas flows injected for fibre production and as a result of their elevated velocity represent regions of reduced static pressure, are located in relatively close mutual vicinity and exert a mutual suction effect which can lead to unstable oscillating flows in the individual core streams or in the fibre flow as a whole. The overall result is that, above the accumulating conveyor, there is a heterogeneous, spatially and temporally unstable flow pattern which, although in snapshot terms can be regarded as a downward flow, nevertheless exhibits locally a plurality of different flow components acting in the most varied of directions. The minutest changes in a boundary condition lead in this chaotic flow system to changes in the flow pattern which are difficult to control from the outside, which changes, in turn, adversely affect the degree of uniformity with which the nonwoven is formed and which are therefore undesirable.
In the boundary zone in particular around the fibre flows, fibres exhibiting rapid upward movements can also be observed. These upward streams in the boundary zone of the fibre flows are attributable to the fact that, as a rule, only a certain portion of the process air flowing in from above is completely extracted, while another portion at the side of the actual fibre flows is pushed upward again, or is sucked upward by partial vacuum zones in the region of the injected drawing gas flows. These air streams exhibit high flow velocities in an upward direction and entrain fibres in an upward direction to the area of fiberisation. In the case of fibre production by the blast drawing process, for example, suction of already solidified fibres into the nozzle slot together with the secondary air can lead to massive disruptions to production. In addition, the transport of already solidified fibres into the region of binder injection which, in the blast drawing process, is usually located at the entry zone of the chute, can lead to these fibre elements once again coming into contact with binder and then adhering to the chute wall or falling onto the nonwoven fabric as fibres with an excessive accumulation of binder, for example in the form of highly undesirable lumps.
In order to achieve orderly fibre deposition under these conditions, it is necessary to perform a plurality of fine adjustments for a given production process, so as to optimise, by trial and error, the fibre deposition conditions. Any change in the production conditions leads to the requirement that new fine adjustment be performed.
SUMMARY OF THE INVENTION
The object of the invention is to provide a process, and an apparatus for performing said process, in which a stable flow is produced in the chute, thus enabling properly defined, homogeneous fibre deposition.
In the first instance, the invention is based on the knowledge that the backflow regions of high velocity, which are formed as a result of the chaotic flow conditions and which, at first sight, appear to be highly undesirable, cannot be forced into a certain flow pattern by additional constructional measures such as, for example, baffles. Rather, in contrast to such an approach and in keeping with the invention, the backflow regions are rendered even larger in volume terms; initially this has the effect that the mean velocity of the backflows is reduced, thus substantially diminishing the extent to which fibres can be transported upward. Surprisingly, moreover, it has been revealed that, rather than a reduction in the backflow regions which are characteristic of the chaotic flow system leading to a stabilisation in the flow pattern, as might have been expected, it is, in contrast, the increase in the space available for the generation of backflow regions which leads to a stabilisation of the flow system. According to the invention, therefore, the backflow regions occurring on the outside of the fibre flows are not constricted but rather increased in volume terms.
Through this measure, the backflow regions have, on the one hand, room at the side to enable them to circulate slowly so that the upward velocities generated are reduced, thus already diminishing the tendency for fibres to be entrained upward; on the other hand, disadvantageous encrustations of binder-containing wool accumulations are avoided in that area of wall in which the stagnation point of the branching flow is located. Above the stagnation point, there is a backflow of process air, while below the stagnation point, the process air is extracted through the accumulating conveyor. If the volumes available for the backflow are too small, wool constituents in the region of the said stagnation point impinge onto the wall with a high velocity component perpendicular to the wall. This leads to undesirable encrustations. According to the invention, this stagnation point is therefore relocated a sufficient distance away from the external enveloping surfaces of the fibre flows so that the disruptive velocity component of the flow in the vicinity of the stagnation point is drastically reduced.
A further and essential aspect of the present invention lies in the fact that the extended backflow zone is dimensioned such that, over and beyond the advantages described so far, the wool to be deposited can no longer follow the backflow in the lower flow deflection area, i.e. it is effectively centrifuged out as in a cyclonic flow. In this process, the wool to be deposited is already separated within the actual chute from an appreciable portion of its associated process air. Consequently, this portion no longer needs to be sucked through the nonwoven fabric. This leads to advantages in respect of the necessary suction energy input, this being reduced owing to the substantially lower pressure loss a) of this partial flow, and b) of the remaining process air passing through the nonwoven fabric and/or the accumulating conveyor. Moreover, the differential pressure necessary for extracting the process air from the nonwoven fabric is also therefore reduced, so that the nonwoven fabric is deposited as a more voluminous material, thus facilitating the manufacture of products of low bulk density.
The overall result is a defined limitation of the fibre deposition area and thus of the nonwoven fabric formation zone, provided not by the walls of the chute but by a boundary area formed between the outsides of the fibre flows and those of the backflow regions.
If extraction of a portion of the process air is performed not through the nonwoven fabric but outside the nonwoven formation zone, the limitation of this zone is assisted by the process air flow, and the extraction of large volumes of air is facilitated.
The fact that the walls of the chute are positioned further out in a deliberately created dead flow zone means, however, that binder-containing wool material which has become deposited in the course of a certain time on the wall, can cure onto the wall more readily. If, in contrast, the chute walls mechanically limit the actual main flow, then they are also exposed to the stream forces acting here which, being mainly parallel to the wall surface, are more appropriate so that fibre encrustations become less probable. With the walls being positioned away from the main streams, the cooling of the walls therefore becomes even more important as a means of preventing, in accordance with the doctrine of published German patent application DE-OS 35 09 425, the curing of binder-containing fibre material onto the circumferential walls of the chute. With respect to further details, features and advantages of the cooling system for the walls of the chute, express reference is made to DE-OS 35 09 425, the full contents thereof being hereby incorporated by reference.
Further details, aspects and advantages of the present invention are revealed in the following description of an embodiment by reference to the drawing in which
FIG. 1 shows a schematic representation by way of illustration of the process according to the invention and the apparatus according to the invention, with an accumulating conveyor in the form a flat conveyor belt, and
FIG. 2 shows a further embodiment of the apparatus according to the invention with a drum-shaped accumulating conveyor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is apparent from FIG. 1, free jet bundles 5, 6, 7 and 8, which are roughly wedge-shaped in their geometry, are produced by, in this illustrative example, four fiberisation units 1, 2, 3 and 4 operating in accordance with the blast drawing process, said free jet bundles 5, 6, 7 and 8 consisting of a fibre/gas/air/ binder mixture, being surrounded by a box-shaped chute 9, the upper terminations 9a to 9e of which are formed by covers 9a to 9e which limit the entry of ambient air. The chute covers 9a to 9e are of moveable design in respect of their cover area, and are also water-cooled in order to minimise the occurrence on them of encrustations of binder-containing wool constituents. Through their limiting effect on the sucked-in false air, signified by 48 to 51, backflows are generated, the extent of which is determined by the position and size of the remaining upper inlet cross sections of the chute. The bottom termination of the chute is formed by an accumulating conveyor 10 featuring a gas-permeable conveyor belt 12 which rotates in accordance with the direction indicated by arrow 11. If the fibre/gas/air mixture, which may also contain a binder, impinges on the accumulating conveyor 10, the gas/air mixture is extracted from below the accumulating conveyor 10 acting as a filter by, in this illustrative example, two extraction devices 13, 14, and the wool is deposited with the formation of a nonwoven fabric onto the accumulating conveyor 10 as a wool nonwoven 15.
The free jet bundles 5 to 8, which are initially still wedge-shaped in their geometry, produced by the fiberisation units 1 to 4, form at the entry zone of the chute 9 fibre flows 16, 17, 18, 19 with interposed eddy zones 20, 21, 22 of entrained process air. After a fall of a certain distance in the chute 9, the individual fibre flows 16 to 19 come into contact with one another and eventually join to form a main flow 23 which likewise features, on its outside, eddy zones 24, 25 with backflow regions 26, 27. According to the invention, the lateral limiting walls 28, 29 of the chute 9 are positioned at a sufficiently large distance from the outside edge 30, 31 of the fibre flows, i.e. the main flow 23, so that there is at least sufficient room for the eddy zones 24, 25 to ensure that the backflow regions 26, 27 which occur exhibit small mean velocities. In this way the problem is avoided whereby fibres from the main flow 23 are transported back up into the entry zone of the chute via the eddy zones 24, 25, in which entry zone they may be sprayed anew with binder.
The shape of the eddy zones 24, 25 leads, in the edge zone of the main flow 23, to a division in the downwardly directed air stream into a portion 32 which is returned upward in the backflow region 26, and a portion 33 which is extracted in the vicinity of, but outside, the nonwoven formation zone 35, namely in a zone 36 with a width a in the illustrative example, by the extraction device 13. The remaining portion 34 is sucked through the nonwoven fabric 15 in the nonwoven formation zone 35 with a width b by extraction device 14. Depending on requirements, instead of extraction device 14, several such extraction chambers can, of course, be provided, duly designed and arranged in accordance with the layer growth of the nonwoven fabric. Moreover, extraction chamber 13 in particular can be dispensed with or take the form of a--if necessary throttlable--part of extraction device 14.
As shown in the right-hand part of the illustration, a large-volume flow is also generated in the region of maximum nonwoven layer thickness, in accordance with the invention, so that appreciable upward wool transport is avoided. To this, a zone c where there is no nonwoven formation can be connected in a similar manner, from which zone c a further partial flow of process air 33b can be extracted by an extraction device 13b which is not shown in any further detail and which is located outside the nonwoven formation and conveying region.
The distance of the lateral limiting walls 28, 29 of the chute from the outside edge 30, 31 of the main flow 23, and also the width a of zone 36, and the width b of the nonwoven formation zone 35 are dimensioned in this respect such that disruptive velocity components perpendicular to the limiting wall 28, 29 in the vicinity of the stagnation point signified by 37 are drastically reduced in magnitude. It is known from earlier measurements that these velocities can easily lie in a range from approx. 10 to 20 m/s. According to the invention they are reduced to below 10 to 20% of these values.
The following data are provided to serve as an indication of the volumes involved in the case of the claimed backflow regions:
Given a process gas volume flow of, for example 9,000 m 3 /h (STP) per fiberisation unit, the volume of circulating backflow generated between the end walls 28, 29 and the enveloping surfaces 30, 31 near to the wall is approx. 2,500 m 3 /h (STP). According to the previously customary design in respect of the distance between fiberisation units 1 and 4 on the one hand, and the end walls 28 and 29 respectively on the other, maximum velocities of the upward flows near to the wall of approx. 4 m/s are known to have occurred. These velocities are higher than the drop velocity of wool flocks, so that a substantial proportion of wool is taken upward again into the chute entry zone.
With the creation in accordance with the invention of sufficiently sized backflow regions, the circulating backflow volumes of 2,500 m 3 /h (STP), although only having undergone insignificant change, feature substantially reduced upward velocity with values falling to below 2 m/s and preferentially below 1 m/s.
As a result of the likewise advantageous introduction of a nonwoven-free extraction region a and/or c, approx. 20 to 80%, and preferentially 40 to 60%, of the process air volume from the fiberisation units 1 and 4 near the wall is, in addition, extracted outside the nonwoven formation zone b, without the need to overcome a pressure loss as a result of flow resistance at the nonwoven. In the case of the four fiberisation units in the illustrative example, a portion of 10 to 40% of the process air is extracted without any appreciable pressure loss, and thus with extreme cost-efficiency.
As a further advantage, reference is made to the fact that, if the edge zone extension according to the invention is not provided, the 9,000 m 3 /h (STP) process air per fiberisation unit mentioned in the example numerical data above can only be adhered to in the case of very coarse wool (such as is required, for example, for automotive exhaust mufflers) featuring correspondingly higher drop velocities and a lower level of permeation resistance. In the case of finer wool, the proportion of false air sucked into the chute per fiberisation unit has to be increased by approx. 3,000 to 6,000 m 3 /h (STP) in order to avoid upward wool transport. By this means, the position of the backflow regions which are formed is shifted so far down that wool egress out of the chute cover area no longer takes place. Compared with these practical operating data, the invention results in an advantageous reduction of the requisite total volume of exhaust air per fiberisation unit of approx. 20 to 60%, and on average approx. 30%.
FIG. 2 shows a further embodiment of the apparatus according to the invention, in which the accumulating conveyor 10 is designed in the form of drums 38, 39. The drums 38 and 39 each feature a rotating, perforated (gas-permeable) rotor 40 and 41, each of which is powered by a motor (not depicted in any further detail in FIG. 2) in the direction of the arrows 42, i.e. the conveying direction. Furthermore, arranged inside the drums 38 and 39 is an extraction device, not depicted in any further detail, the suction pressure generated by which is active only in suction chambers 45 and 46 located below the curved suction areas 43 and 44. The distance between the two drums 38 and 39 creates a so-called discharge gap 47, the width of which is essentially to be matched to the thickness of the nonwoven 15 being produced. In order to adjust the width of the discharge gap 47, one of the two drums 38, 39 may be of swivellable design. In order to optimise the large-volume flow structure, the extraction devices 45 and 46 may, in particular, be divided such that the suction pressure in the nonwoven-free suction zones a is adjustable.
In this embodiment, the extraction zone a shown in example 1 (see FIG. 1) is arranged to particular advantage as, owing to the two, initially nonwoven-free perforated surfaces entering the chute, there are two extraction zones a formed which, without any great degree of design sophistication, serve the purpose according to the invention of extracting a considerable portion of the process air from outside the nonwoven deposition surface. This eliminates what would be, in itself, a more difficult problem, namely that of providing a further extraction device 13b analog to region c in FIG. 1. By this dual utilisation of the advantages of a nonwoven-free zone a, the formation of zones c in this concept can be avoided to advantageous effect. | The objective is to provide a process and an apparatus for the continuous production of mineral wool nonwovens, by means of which a stable flow pattern is created in the chute, thus facilitating a clearly defined, homogeneous layer of deposited mineral wool.
According to the invention, at least one backflow region (24, 25) is generated in the chute (9) outside the fibre flow (23), which backflow region (24, 25) is sufficient for such a large-volume backflow with such a low mean velocity that appreciable upward fibre transport is avoided. In this connection, a portion (32) of the process air entrained with the fibre flow is deflected upward in the backflow, and another portion (34) of the process air is extracted. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is related to Indian Patent Application No. 2818/Del/2006, filed Dec. 28, 2006, entitled “A COMPENSATED OUTPUT BUFFER FOR IMPROVING SLEW CONTROL RATE”. Indian Patent Application No. 2818/Del/2006 is assigned to the assignee of the present application and is hereby incorporated by reference into the present disclosure as if fully set forth herein. The present application hereby claims priority under 35 U.S.C. §119(a) to Indian Patent Application No. 2818/Del/2006.
TECHNICAL FIELD
The present invention relates to the field of input/output (I/O) systems in the semiconductor technology. In particular, the invention discloses an output buffer system having very less current slew rate variations over varied process, voltage and temperature (PVT) conditions.
BACKGROUND
In semiconductor integrated circuits, output buffer circuits are generally used to output an internal data via an output terminal such as, an output pad. As the interface grows up, output drivers have been an important component for high quality signals integrity, because the output voltage levels and a slew rate are mainly determined by the output drivers.
The operating characteristics of CMOS transistors, from which the drivers are constructed, change under a variety of conditions, often referred to as process, voltage and temperature (PVT) variations. The PVT variations may be conceptualized as a box across, which the operating characteristics of the transistors move. For example, the operating characteristics may move from a fastest corner of the PVT variations to a slowest corner of the PVT variations, and everywhere in between. If inadequate compensation is made for these variations, an output slew rate may vary substantially within a particular driver as well as from a driver to a driver on a chip.
To achieve good signal integrity, the variations in an output current slew rate must be minimized over the PVT variations. A large slew rate induces much switching noise, (L*di/dt) noise, and a small slew rate decrease the signal timing margin. In a conventional output slew rate control scheme, a pre-driver is set to a fixed value, so the time constant (RC) of a pre-driver node determines the output slew rate. But, if PVT conditions vary, the time constant becomes different, so the slew rate goes far from its optimal values.
FIG. 1 describes a schematic circuit diagram of a conventional split-gate output driver. The output buffer includes a pull-up PMOS transistor P 11 and a pull-down NMOS transistor N 11 ; two pre-driver sections (slew rate control sections) to individually control each driver's transistor during output transitions viz. a first inverter 104 that inverts an output data A, applies an inverted output data to a gate of the pull-up transistor P 11 , and controls the pull-up slew rate of an output driver 102 ; and a second inverter 106 that applies the inverted output data to a gate of the pull-down transistor N 11 , and controls the pull-down slew rate of the output driver 102 .
In the output buffer circuit of the FIG. 1 , the pull-up slew rate of the output driver 102 is determined based on a current flow charging the load capacitance of an output terminal PAD through the pull-up transistor P 11 and the fall time of the pre-driver node PD, which in turn is controlled by a current of the NMOS transistor N 12 . Similarly, the pull-down slew rate of the output driver 102 is determined based on a current flow discharging the load capacitance of an output terminal PAD through the pull-down transistor N 11 and the fall time of the pre-driver node ND, which in turn is controlled by the current of PMOS transistor P 13 .
These currents, which affect the slew rate of the output driver 102 varies considerably in the presence of PVT variations on a chip. Accordingly, the slew rate of the output driver 102 also varies considerably in the presence of PVT variations. The conventional output buffer circuit as, explained in the FIG. 1 , it is difficult to maintain the slew rate within a narrow tolerance under conditions in which the PVT may vary.
Therefore, there is a need for a novel circuit and method for providing an improved slew rate control over process, voltage and temperature (PVT) conditions.
SUMMARY
It is an object of the present invention to provide a compensated output buffer for minimizing the variations in a current slew rate over process, voltage and temperature (PVT) conditions.
It is another object of the present invention to provide a compensated output buffer for maintaining the variation of the slew rate within a narrow band even for skewed process corners i.e. fast n-slow p and slow n-fast p.
To achieve the aforementioned objective, the present invention provides a compensated output buffer circuit providing an improved slew rate control comprising:
a compensated output driver utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated output driver coupled to a first driving node, a second driving node and an output node, the compensated output driver having a pull-up driver section for driving said output node in response to a signal at the first driving node and a pull down driver section for driving said output node in response to a signal at the second driving node;
a compensated pull-up slew rate controller utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated pull-up slew rate controller connected between an input node and the compensated output driver through the first driving node for controlling a pull-up slew rate of the compensated output driver during a transition of an output from 0 to 1; and
a compensated pull-down slew rate controller utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated pull-down slew rate controller connected between the input node and the compensated output driver through the second driving node for controlling a pull-down slew rate of the compensated output driver during a transition of the output from 1 to 0 to minimize the variations in the current slew rate of the output buffer over process, voltage and temperature condition for improving the slew rate control.
Further the present invention provides a compensated output buffer circuit providing an improved slew rate control comprising:
a compensated output driver utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated output driver coupled to a first driving node, a second driving node and an output node, the compensated output driver having a pull-up driver section for driving said output node in response to a signal at the first driving node and a pull down driver section for driving said output node in response to a signal at the second driving node;
a compensated pull-up slew rate controller utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated pull-up slew rate controller controlling a pull-up slew rate of the compensated output driver comprising:
an inverter circuit coupled between an input node and the first driving node for inverting data of the input node and outputting an inverted data to the first driving node, the inverter circuit comprising a first PMOS transistor and a first NMOS transistor;
a first control signal generator coupled to the input node for generating a first control signal;
a second NMOS transistor operatively coupled between a first node and a ground voltage for switching, said second NMOS transistor being controlled by the first control signal;
a third NMOS transistor connected parallel to the second NMOS transistor, said third NMOS transistor operatively coupled between the first node and the ground voltage for discharging a parasitic capacitance developed at the first driving node;
a fourth NMOS diode transistor operatively coupled between a second node and the ground voltage;
means for generating a first current mirror for providing a proportionate current to a first slew rate control path;
a second PMOS transistor connected between the second node and a third node for switching, said second PMOS transistor being controlled by the first control signal; and
a PMOS module coupled between a power supply and the third node, said module comprising a plurality of PMOS transistors for controlling a current in a slew rate control path formed by the first NMOS transistor and the third NMOS transistor;
a compensated pull-down slew rate controller utilizing a separate compensation codes for PMOS transistors and NMOS transistors, said compensated pull-down slew rate controller controlling a pull-down slew rate of the compensated output driver comprising:
an inverter circuit coupled between the input node and the second driving node for inverting data of the input node and outputting an inverted data to the second driving node, said inverter comprising a third PMOS transistor and a fifth NMOS transistor;
a second control signal generator coupled to the input node for generating a second control signal;
a fourth PMOS transistor connected between the power supply and a fourth node for switching, said fourth PMOS transistor being controlled by the second control signal;
a fifth PMOS transistor connected parallel to the fourth PMOS transistor, said fifth PMOS transistor operatively coupled between the power supply and the fourth node for charging a parasitic capacitance at the second driving node;
a sixth PMOS diode transistor connected between the power supply and a fifth node;
means for generating a second current mirror for providing a proportionate current to a second slew rate control path;
a sixth NMOS transistor connected between the fifth node and a sixth node for switching, said sixth NMOS transistor being controlled by the second control signal; and
an NMOS module coupled between the sixth node and the ground voltage, said NMOS module comprising a plurality of NMOS transistors for controlling a current in a slew rate control path formed by the third PMOS transistor and the fifth PMOS transistor for improving the slew rate control.
Further the present invention provides a method for minimizing slew rate variations through a compensated output buffer circuit, said output buffer comprising a pull-up slew rate controller, a pull-down slew rate controller and a compensated output driver, said method comprising controlling a current generated in a slew rate control path through a separate compensation codes for PMOS transistors and NMOS transistors that control a plurality of transistors in said pull-up slew rate controller and said pull-down slew rate controller for minimizing slew rate variations.
The drawbacks and disadvantages are addressed by an output buffer for buffering the data while minimizing an output current slew rate variations caused by PVT variations. Accordingly, the output buffer, usable in a semiconductor integrated circuit, is provided to minimize the variations in the current slew rate of the buffer over process, voltage and temperature (PVT) conditions, which includes within the buffer a split-gate compensated driver and a slew rate control circuit. Accordingly, a desired slew rate can be maintained with fewer variations over wide range of variations in PVT conditions. The present slew rate control circuit consists of two separate slew rate control circuits for a pull-up PMOS driver and a pull-down NMOS driver. To minimize the variations in the slew rate, the rising and falling time of the pre-driver nodes are controlled by means of two current control networks, which are compensated against PVT variations by using separate NMOS and PMOS digital compensation codes. The compensation codes are provided by a compensation circuit, which sense the variation in the PVT conditions and reflect these variations in the form of separate compensation codes for NMOS and PMOS transistors. In the current control network for PMOS (NMOS) driver, the current is controlled only by PMOS (NMOS) transistors, which enables the circuit to reduce the slew rate variation effectively on skewed process corners i.e. fast n-slow p and slow n-fast p.
Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this present disclosure and its features, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a schematic circuit diagram for a conventional split-gate output buffer circuit;
FIG. 2 illustrates a schematic block diagram for an output buffer circuit according to an embodiment of the present disclosure;
FIG. 3 illustrates schematic circuit diagram for the generic compensated pull-up slew rate controller of FIG. 2 ;
FIG. 4 illustrates schematic circuit diagram for a specific 4-bit compensated pull-up slew rate controller of FIG. 2 ;
FIG. 5 illustrates the schematic circuit diagram for a control signal generator of FIG. 4 ;
FIG. 6 illustrates a schematic circuit diagram for the generic compensated pull-down slew rate controller of FIG. 2 ;
FIG. 7 illustrates a schematic circuit diagram for a specific 4-bit compensated pull-down slew rate controller of FIG. 2 ;
FIG. 8 illustrates a schematic circuit diagram for a control signal generator of FIG. 7 ;
FIG. 9 illustrates a schematic circuit diagram of a preferred embodiment for a compensated output driver of FIG. 2 ;
FIG. 10 illustrates a graph for the in pull-up slew rate variations for a compensated and uncompensated output buffer;
FIG. 11 illustrates a graph for variation in pull-down slew rates for the compensated and uncompensated output buffer; and
FIG. 12 illustrates a flow diagram of a method for minimizing slew rate variations through a compensated output buffer circuit according to the present invention.
DETAILED DESCRIPTION
The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the preferred embodiments. The present invention can be modified in various forms. The preferred embodiments of the present invention are only provided to explain more clearly the present invention to the ordinarily skilled in the art of the present invention. In the accompanying drawings, like reference numerals are used to indicate like components.
The present invention provides a compensated output buffer circuit having an improved slew rate control.
FIG. 2 illustrates a schematic block diagram of an output buffer circuit according to an embodiment of the present invention. The output buffer circuit includes a compensated output driver 202 , a compensated pull-up slew rate controller 204 and a compensated pull-down slew rate controller 206 .
The compensated output driver 202 is connected between a first driving node PD and a second driving node ND and an output node PAD. The compensated output driver 202 drives a load capacitance C L in response to signals at nodes PD and ND. The compensated output driver 202 consists of a pull-up driver section and a pull-down driver section. The pull-up driver drives the output node PAD in response to a signal at the node PD and the pull-down driver section drives the output node PAD in response to a signal at the node ND. The compensation codes COMPP [n: 0 ] and COMPN [n: 0 ] are used to compensate current driving capability of the output driver 202 against PVT variations.
The compensated pull-up slew rate controller 204 is connected between nodes A and the node PD, the driving node for the pull-up driver. The compensated pull-up slew rate controller 204 controls the pull-up slew rate of the output driver 202 , when output makes a transition from 0 to 1. The compensation codes COMPP [n: 0 ] are used to generate control signals in the pull-up slew rate controller 204 .
The compensated pull-down slew rate controller 206 is connected between nodes A and the node ND, the driving node for pull-down driver. The compensated pull-down slew rate controller 206 controls the pull-down slew rate of the output driver 202 when output makes a transition from 1 to 0. The compensation codes COMPN [n: 0 ] are used to generate control signals in the pull-down slew rate controller 206 .
FIG. 3 illustrates the schematic circuit diagram of a generic compensated pull-up slew rate controller described in FIG. 2 .
The compensated pull-up slew rate controller 204 includes an inverter circuit coupled between an input node A and the first driving node PD for inverting data of the input node A and outputting an inverted data at the first driving node PD, a first control signal generator coupled at the input node A having a NAND gate configured to receive complementary inputs for generating a first control signal CTRLP, a second NMOS transistor N 32 connected between a first node A 1 and a ground voltage to act as a switch and is controlled by the first control signal CTRLP, a third NMOS transistor N 33 connected in parallel to the second NMOS transistor N 32 and is connected between the first node A 1 and the ground voltage for discharging the parasitic capacitance developed at the first driving node PD through a first slew rate control path formed by a first NMOS transistor N 31 and the third NMOS transistor N 33 , a fourth NMOS transistor N 34 connected in a diode configuration between a second node A 2 and the ground voltage, a second PMOS transistor P 32 connected between the second node A 2 and a third node A 3 to act as a switch, which is controlled by the first control signal CTRLP and a PMOS module coupled between a power supply and the third node A 3 for controlling the current in the first slew rate control path. The PMOS module includes multiple PMOS transistors P 33 , P 34 , - - - , P 3 n and their connections are shown in the FIG. 3 .
The inverter of the compensated pull-up slew rate controller 204 includes a first PMOS transistor P 31 and the first NMOS transistor N 31 . The first PMOS transistor P 31 having a source terminal connected to the power supply, a drain terminal connected to the first driving node PD and a gate terminal connected to the input node A. The first NMOS transistor N 31 having a drain terminal connected to the drain terminal of the first PMOS transistor P 31 through the first driving node PD, a source terminal connected to the first node A 1 and a gate terminal connected to the gate terminal of the first PMOS transistor P 31 through the input node A. The first PMOS transistor P 31 is configured with the first NMOS transistor N 31 in an inverter configuration.
FIG. 4 illustrates the schematic circuit diagram of a specific 4-bit compensated pull-up slew rate controller according to an embodiment of FIG. 3 . The compensated pull-up slew rate controller implements an inverter for inverting the data at node A and outputting the inverted data to the output node PD. When a transition from 0 to 1 occurs at the node A, the parasitic capacitance (constituted mainly by a gate capacitance of pull-up driver section) at a pre-driver node PD is discharged through the first slew rate control path formed by NMOS transistors N 41 and N 43 . The current in this path is controlled by PMOS transistors P 43 through P 47 . The NMOS transistors N 43 and N 44 constitute a first current mirror and copies a current I SPU to the first slew rate control path. The value of the current I SPU is controlled by the PMOS transistors P 43 through P 47 . The PMOS transistor P 43 is always “ON”, while the PMOS transistors P 44 through P 47 are gate-controlled by the control signals C 3 P through C 0 P. The control signals C 3 P through C 0 P are derived by simply inverting compensation codes COMPP 3 through COMPP 0 through inverters 41 through 44 . These compensation codes COMPP [ 3 : 0 ] are provided by a compensation circuit, which sense the variation in PVT conditions and reflect these variations in the form of separate compensation codes for NMOS and PMOS transistors. The bits of N compensation code (P compensation code) reflect the change in current characteristics of NMOS (PMOS) transistors due to changing the PVT conditions. Here, the compensation circuit has been assumed to provide 4-bits compensation codes. In general, compensation codes of n-bits can be obtained from an n-bit compensation circuit.
As the value of the compensation codes vary with change in the PVT conditions, the control signals C 3 P through C 0 P also vary with change in PVT conditions. For the best case, the bits of PMOS compensation codes are all zero i.e. COMPP [3:0]=0000 and the control signals C 3 P through C 0 P are all 1's and hence all the PMOS transistors P 44 through P 47 are in “OFF” state. For the worst case, the bits of PMOS compensation codes are all 1's i.e. COMPP [3:0]=1111 and the control signals C 3 P through C 0 P are all 0's and hence all the PMOS transistors P 44 through P 47 turn “ON”, thus compensating for the loss in the current I SPU caused due to slowing PVT conditions and thus maintaining the slew rate variations in a narrow band.
Thus, based on the PVT conditions the PMOS transistors P 44 through P 47 are turned “OFF/ON” by the control signals C 3 P through C 0 P. Accordingly, the current I SPU is, in effect, controlled and compensated against PVT variations by changing compensation codes and hence, the slew rate is also compensated by means of the compensated current I SPU .
There are two transistors, the NMOS transistor N 42 and the PMOS transistor P 42 , which act as switches and their gates are controlled by the signal CTRLP. The function of the CTRLP signal is to prevent steady state consumption in the compensated pull-up slew rate controller. Whenever, a transition from 0 to 1 occurs on the node A, the CTRLP signal goes to 0, thus turning the NMOS transistor N 42 “OFF” and the PMOS transistor P 42 “ON”. This allows the current through the slew rate control path to be controlled by the PMOS transistors P 43 through P 47 . But, when the circuit is in a steady state, the CTRLP signal goes to 1 enabling the NMOS transistor N 42 to “ON” state and turning “OFF” the PMOS transistor P 42 , which in turn causes the current I SPU to cease to 0. Thus, if the steady state value of the node A is 1, the node PD is pulled down through the current path formed by the NMOS transistors N 41 and N 42 .
FIG. 5 illustrates a schematic circuit diagram for the control signal generator of FIG. 4 . The control signal generator generates a control signal CTRLP. The control signal generator having a NAND gate, which is configured to receive complementary inputs for generating the control signal CTRLP.
FIG. 6 illustrates a schematic circuit diagram of a generic compensated pull-down slew rate controller as introduced in FIG. 2 . The compensated pull-down slew rate controller 206 includes an inverter circuit coupled between an input node A and a second driving node ND for inverting data of the input node A and outputting an inverted data to the second driving node ND, a second control signal generator coupled to the input node A for generating a second control signal CTRLN, a fourth PMOS transistor P 62 connected between the power supply and a fourth node B 1 to act as a switch and is controlled by the second control signal CTRLN, a fifth PMOS transistor P 63 coupled in parallel to the fourth PMOS transistor P 62 and is connected between the power supply and the fourth node B 1 for charging a parasitic capacitance at the second driving node ND through a second slew rate control path formed by a third PMOS transistor P 61 and the fifth PMOS transistor P 63 , a sixth PMOS transistor P 64 coupled in a diode configuration connected between a power supply and a fifth node B 2 , a sixth NMOS transistor N 62 connected between the fifth node B 2 and a sixth node B 3 to act as a switch and is controlled by the second control signal CTRLN and an NMOS module coupled between the sixth node B 3 and the ground voltage for controlling the current in the second slew rate control path, which in turn minimize the variations in the current slew rate of the output buffer over process, voltage and temperature condition. The NMOS module includes multiple NMOS transistors and their connections are shown in the FIG. 6 .
The inverter of the compensated pull-down slew rate controller 206 includes a third PMOS transistor P 61 and a fifth NMOS transistor N 61 . The third PMOS transistor P 61 having a source terminal connected to the fourth node B 1 , a drain terminal connected to the second driving node ND and a gate terminal connected to the input node A. The fifth NMOS transistor N 61 having a drain terminal connected to the drain terminal of the third PMOS transistor P 61 through the second driving node ND, a source terminal connected to the ground voltage and a gate terminal connected to the gate terminal of the third PMOS transistor P 61 through the input node A. The third PMOS transistor P 61 configured with the fifth NMOS transistor N 61 in an inverter configuration.
FIG. 7 illustrates a schematic circuit diagram of a specific 4-bit compensated pull-down slew rate controller according to an embodiment of FIG. 6 . The compensated pull-down slew rate controller implements an inverter for inverting the data at a node A and outputting the inverted data to a node ND. When a transition from 1 to 0 occurs on the node A, a parasitic capacitance (constituted mainly by a gate capacitance of pull-down driver section) at the pre-driver node ND is charged through the second slew rate control path formed by PMOS transistors P 71 and P 73 . The current in this path is controlled by NMOS transistors N 73 through N 77 . The PMOS transistors P 73 and P 74 constitute a second current mirror and copies a current I SPD to the second slew rate control path. The value of the current I SPD is controlled by NMOS transistors N 73 through N 77 . The NMOS transistor N 73 is always “ON”, while the NMOS transistors N 74 through N 77 have their gates controlled by control signals C 3 N through CON. The control signals C 3 N through CON are derived by simply buffering compensation codes COMPN 3 through COMPN 0 using simple buffers 71 through 74 . These compensation codes COMPN [ 3 : 0 ] are provided by the compensation circuit, which sense the variation in the PVT conditions and reflect these variations in the form of separate compensation codes for the NMOS and PMOS transistors.
As the value of the compensation codes vary with change in the PVT conditions, the control signals C 3 N through CON also vary with change in the PVT conditions. For the best case, the bits of NMOS compensation codes are all “0” i.e. COMPN [3:0]=0000 and the control signals C 3 N through CON are all 0's and hence all the NMOS transistors N 74 through N 77 are “OFF”. For the worst case, the bits of compensation codes are all 1's i.e. COMPN [3:0]=1111 and the control signals C 3 N through CON are all 1's and hence all the NMOS transistors N 74 through N 77 turn “ON”, thus compensating for the loss in the current I SPD caused due to slowing the PVT conditions and thus maintaining the slew rate variations in a narrow band.
Thus, based on the PVT conditions the NMOS transistors N 74 through N 77 are turned “OFF/ON” by the control signals C 3 N through CON. Accordingly, the current I SPD is, in effect, controlled and compensated against PVT variations by changing compensation codes and hence, the slew rate is also compensated by means of the compensated current I SPD .
There are two transistors, a PMOS transistor P 72 and a NMOS transistor N 72 , which act as switches and their gates are controlled by the signal CTRLN. The function of the CTRLN signal is to prevent steady state consumption in the compensated pull-down slew rate controller. Whenever, a transition from 1 to 0 occurs on the node A, the CTRLN signal goes to 1, thus turning the PMOS transistor P 72 “OFF” and NMOS transistor N 72 “ON”. This allows the current through the slew rate control path to be controlled by the NMOS transistors N 73 through N 77 . But, when the circuit is in the steady state, the CTRLN signal goes to 0 enabling the PMOS transistor P 72 to “ON” state and turning “OFF” the NMOS transistor N 72 , which in turn causes the current I SPD to cease to 0. Thus, if the steady state value of the node A is 0, the node ND is pulled up through the current path formed by the PMOS transistors P 71 and P 72 .
FIG. 8 illustrates the schematic diagram for control signal generator of FIG. 7 . The control signal generator generates a second control signal CTRLN. The control signal generator having a NOR gate, which is configured to receive complementary inputs for generating the second control signal.
FIG. 9 illustrates a schematic circuit diagram of a preferred embodiment for the compensated output driver of FIG. 2 . The compensation codes COMPN [ 0 : 3 ] and COMPP [ 0 : 3 ] are used to design a variable width O/P driver, thereby controlling the current driving capability of the driver, such that the variations in current drive are minimized against PVT variations. A circuit 902 is always “ON”, while a controllable circuits 904 through 910 are ON or OFF depending upon the codes COMPN [ 0 : 3 ] and COMPP [ 0 : 3 ]. For best case, only the circuit 902 is “ON”, while the rest of the circuit viz. 904 , 906 , 908 and 910 are “OFF”. As the PVT conditions move from worst to best, the controllable circuits get turning “ON” depending upon the codes COMPN [ 0 : 3 ] and COMPP [ 0 : 3 ], thus compensating against the loss in current capability due to worsening PVT conditions. For a worst case, all the circuits 902 through 910 are “ON”. Thus, the loss current capability of the O/P driver is compensated over the whole PVT conditions.
In an embodiment, a design for a 4-bit compensated output buffer has been explained. In other embodiments, an n-bit compensated output buffer with the improved slew rate control can be designed with an n-bit compensated pull-up slew rate controller, an n-bit compensated pull-down slew rate controller and an n-bit compensated output driver in accordance with FIGURES provided herewith.
FIG. 10 illustrates the variation of pull-up slew rates for two output buffer types: a compensated output buffer designed in accordance with the present invention and an uncompensated output buffer, for example, one as shown in FIG. 1 .
FIG. 11 illustrates the variation of pull-down slew rates for two output buffer types: the compensated output buffer designed in accordance with the present invention and the uncompensated output buffer, for example, one as shown in FIG. 1 .
FIG. 12 illustrates a flow diagram of a method for minimizing slew rate variations through a compensated output buffer circuit according to an embodiment of the present invention. At step 1202 , a generated current is controlled in a slew rate control path through a separate compensation codes for PMOS transistors and NMOS transistors that control a plurality of transistors in said pull-up slew rate controller and said pull-down slew rate controller for minimizing slew rate variations.
The output buffer circuit as described in the present invention offers many advantages. The output buffer circuit according to the present invention is capable of minimizing the slew rate variations over the PVT range. Further, the present invention helps in maintaining the variation of the slew rate within a narrow band even for skewed process corners i.e. fast n-slow p and slow n-fast p. Since the pull-up slew rate for the PMOS output driver is controlled by PMOS transistors and the pull-down slew rate for the NMOS output driver is controlled by NMOS transistors only, the slew rate variation is minimized even on skewed process corners. The variation in the slew rate is more for the case where, for example, pull-up slew rate is simply controlled by NMOS transistors which are gate controlled by PMOS compensation codes.
Although the disclosure of circuit and method has been described in connection with the embodiment of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made thereto without departing from the scope and spirit of the disclosure.
It may be advantageous to set forth definitions of certain words and phrases used in this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like.
While this present disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this present disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this present disclosure, as defined by the following claims. | The disclosure relates a compensated output buffer circuit providing an improved slew rate control and a method for minimizing the variations in the current slew rate of the buffer over process, voltage and temperature (PVT) conditions. The output buffer circuit includes a split-gate compensated driver and a slew rate control circuit. Accordingly, a desired slew rate can be maintained with fewer variations over wide range of variations in PVT conditions. | 7 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/012,193, filed Jan. 24, 2011, which is a continuation of U.S. patent application Ser. No. 11/737,864, filed Apr. 20, 2007, both of which are incorporated by reference herein in their entireties.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to plumbing fixtures, such as bathroom showers and whirlpools, and more particularly to an electrical control system for operating components of the plumbing fixture and specifically to a user interface of the control system.
[0004] 2. Description of the Related Art
[0005] High end bathroom shower systems provide multiple showerheads mounted on the ceiling and walls of a shower enclosure to direct water onto the bather from multiple directions. Some of these showerheads are similar to those found in standard single showerhead showers, while others provide unconventional spray patterns. For example, the WaterTile (trademark Kohler Co.) showerhead has 22 nozzles that provide a series of water cascades, while other showerheads emit water in a sheet flow. Such a shower enclosure typically has several different types showerheads to provide a variety of water flow effects.
[0006] The water flow to each showerhead is individually controlled by a separate electrically operated valve. In addition to regulating the on/off flow rate, the valve can provide a constant flow or a pulsated flow to produce a massaging effect replicating the rhythmic manipulation of tissue performed by a masseur or masseuse. The different electrically operated valves also can be opened and closed sequentially to create continuously changing water patterns within the shower enclosure.
[0007] The bathing experience is further enhanced by a plurality of different colored lamps that are independently controlled to produce light of varying intensity and color in the shower enclosure. Speakers also provide music, radio news programs and other audio performances to the bather. A steam generator may turn the shower enclosure into a steam bath, when desired.
[0008] Because of the relatively large number of functions that are provided on a top of the line shower system, its operation is governed by a microcomputer based control system. While such computerized control simplifies the hardware necessary to operate all the valves, lights, audio equipment, steam generator and other shower components, the bather still has to select which of the numerous functions are to be active and choose parameters for the selected functions. Heretofore, this required a complex user control panel.
[0009] Thus, there is a need for a simple, easy to use interface by which the bather is able to individually control the numerous functions on a state of the art shower system. Because the interface is intended for location in a wet environment, it must be watertight.
SUMMARY
[0010] A user interface produces signals for controlling a plumbing fixture, such as a shower system for example, that has electrically operated components. The user interface includes an enclosure that has a faceplate with an exterior surface. A display is provided on which alphanumeric characters, symbols and icons are presented to a user of the plumbing fixture. The display is visible through the exterior surface of the faceplate.
[0011] Several user operable input devices are incorporated into the enclosure. A plurality of switches respond to the user pressing a different portion of the faceplate. A selector has a pedestal that projects outward from and is affixed to the faceplate in a watertight manner. A selector ring is rotatably positioned around the pedestal and contains a plurality of permanent magnets arranged annularly. A Hall effect sensor is located adjacent the selector ring and produces an electrical signal in response to motion of the selector ring.
[0012] In a preferred embodiment of the user interface, a controller receives the electrical signal from the Hall effect sensor and determines from that signal whether the selector ring is rotating clockwise or counterclockwise around the pedestal.
[0013] Another aspect of the present user interface is a wireless remote control by which the user also is able to control the plumbing fixture. The a wireless remote control comprises a first switch for activating and deactivating the plumbing fixture, a second switch for selecting one of a plurality of preset operating configurations for the plumbing fixture, and a visual indicator designating which of the plurality of preset operating configurations has been selected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a block schematic diagram of an electronic control system for operating a plumbing fixture;
[0015] FIG. 2 illustrates the faceplate of a user interface for the control system;
[0016] FIG. 3 illustrates a selector ring of a rotary input device that has been removed from the user interface;
[0017] FIG. 4 is a view of one flat face of the control ring;
[0018] FIG. 5 is a cross sectional view along line 5 - 5 in FIG. 4 ;
[0019] FIGS. 6 and 7 depict different types of information being presented on a display of the user interface; and
[0020] FIG. 8 is a perspective view of a wireless remote control for the shower control system.
DETAILED DESCRIPTION
[0021] Although the present invention is being described in the context of controlling a bathroom shower system, it has equal applicability to controlling a whirlpool tub, toilet, or other plumbing fixture. The term “plumbing fixture” as used herein includes a water enclosure, such as a tub, shower enclosure or toilet, as well as the plumbing fittings and components that control the flow of water to and from the water enclosure. However, “plumbing fixture” does not include white goods, such as clothes washing machines, dishwashers and the like.
[0022] With initial reference to FIG. 1 , a control system 10 electrically operates various components of a shower system, such as valves that control the flow of water to a plurality of shower heads, different colored lights within the shower enclosure, and an audio system that provides music or radio programming to the bather. The control system 10 includes a primary controller 12 , a user control panel 14 , and a wireless remote control 16 . The user control panel 14 and wireless remote control 16 collectively form a user interface 15 for the control system. In a typical installation, the primary controller 12 is mounted within a wall adjacent to the shower enclosure and the user control panel 14 is located on a wall of that shower enclosure for access by the bather.
[0023] The primary controller 12 is based around a commercially available microcomputer 18 that includes a processor, a memory for storing control programs and data and input/output circuits for interfacing with other components of the primary controller. Other outputs of the microcomputer 18 are connected to a light output circuit 24 that controls the application of electricity to a plurality of light bulbs 26 mounted in the ceiling and walls of the shower enclosure. The microcomputer 18 also controls the operation of an audio system 28 with speakers 29 mounted within the shower enclosure. The audio system 28 comprises equipment for providing music, radio programming, or other types of audio from different sources and is controlled by the bather via the user control panel 14 . The microcomputer 18 communicates via data interface 41 to a data interface 102 in a digital valve 100 .
[0024] The digital valve 100 has a valve controller 101 with outputs connected to a plurality of valve driver circuits 20 that provide signals for operating a plurality of valves 21 and 22 . A mixing valve 21 selectively combines water from hot and cold sources to produce water at an outlet 23 that has a temperature desired by the bather. That temperature is measured by a sensor 25 which provides a temperature indication signal to the valve controller 101 . The mixing valve outlet 23 is connected to a several solenoid operated valves 22 that control the flow of water to the different shower heads 27 within the shower enclosure. Each solenoid operated valve may feed one or more shower heads. The valve controller 101 also can open and close the valve in a rapid sequence to provide a pulsed flow of water to the shower head 27 .
[0025] The user control panel 14 exchanges control signals with the primary controller 12 through a cable 42 . Specifically one end of the cable 42 is connected to a first data interface 41 in the primary controller 12 and the opposite end is coupled to a second data interface 46 in the user control panel 14 . The two data interfaces 41 and 46 convert data between a parallel format used with the user control panel 14 and the primary controller 12 and a serial format by which the data are transmitted over the cable. The user control panel 14 is based around a controller 44 that includes a microprocessor and a memory for storage of a control program and data. The controller 44 has ports connected to user input and output devices of the user control panel.
[0026] With additional reference to FIG. 2 which shows the faceplate 45 of the user control panel 14 , the controller 44 is connected to a plurality of momentary contact switches 51 , 52 , 53 , and 54 , such as capacitive switches or membrane switches integrated into the exterior surface of the faceplate. The momentary contact switches and the arrangement of other input/output devices on the faceplate 45 , as will be described, avoid the need for holes in the control panel faceplate 45 , and thus prevent water within the shower enclosure from penetrating into the user control panel 14 . The first momentary contact switch 51 toggles the control system 10 between on and off states. Second and third momentary contact switches 52 and 53 enable a bather to select one of six different preset operating configurations of the shower system which have been previously stored in the control system 10 . For example, after a bather has manually set up the shower system to provide a particular water pattern, lighting, and audio selection, that entire operating configuration can be stored as one of the six preset operating configurations. On a subsequent use of the shower enclosure, the bather can restore the shower system to that one of those preset operating configuration by using either the second or third momentary contact switch 52 or 53 . The bather selects a particular preset operating configuration by pressing the appropriate switch 52 or 53 a respective number of times. For example, to select the fifth stored configuration, the bather presses the third momentary contact switch 53 twice. This enables different people to quickly set up the shower system according to their individual preferences. It also enables the same person to have several preset operating configurations to use at different times, such as a morning shower, a workout shower, and an evening shower.
[0027] The user control panel 14 has a display 56 , such as an LCD panel, on which alphanumeric characters and symbols are displayed to the bather. The control panel faceplate 45 has a transparent section that extends over the display in a seamless manner thereby providing a watertight exterior surface of the faceplate so that water cannot penetrate into the user control panel. A fourth momentary contact switch 54 returns information on the display 56 to a previous information screen, as will be described. The user control panel 14 also includes a rotary selector 60 that is used for a number of input functions depending upon the particular information being presented on the display 56 . For example, in FIG. 2 the display 56 contains a list of four different water outlet devices, i.e. a spray head, a hand shower, and two body sprays, that are operated by the control system 10 . By rotating a selector ring 62 of the selector 60 , an input signal is sent to the controller 44 to cause the displayed information to sequentially highlight each of the four output devices in reversed fonts. For example, FIG. 2 shows the Shower Head highlighted which highlighting designates that particular item of information shown on the display. The selector ring 62 can be rotated either clockwise or counterclockwise to respectively move the highlighting down and up the displayed list, respectively. The bather can select the highlighted item by pressing a fifth momentary contact switch 55 in the center of the selector 60 . That action signals the controller 44 that the bather has selected the presently highlighted item being displayed. As will be described in greater detail, the selector ring 62 has a plurality of permanent magnets that activate a commercially available Hall effect sensor 58 located behind the control panel faceplate 45 to provide a signal to the controller 44 that indicates not only motion of the selector ring 62 , but the clockwise or counterclockwise direction of that motion.
[0028] The selector 60 has a unique physical construction which enables the faceplate 45 to have a continuous, uninterrupted exterior surface, that does not have any holes or other openings, thereby preventing water from entering the user control panel 14 . With particular reference to FIG. 3 , the selector 60 comprises a circular, cylindrical pedestal 66 projecting outward from the faceplate 45 in a seamless manner thereby providing a watertight exterior surface of the faceplate. Preferably, the faceplate 45 and the pedestal 66 are molded as a single piece of plastic. The pedestal 66 has a curved side surface 68 and a flat end surface 70 on which the fifth momentary contact switch 55 is mounted. The fifth momentary contact switch 55 , along with the other four switches on the faceplate 45 , are membrane type switches integrated into the exterior surface of the faceplate 45 , thereby also enabling that surface to be contiguous and unbroken.
[0029] With continuing reference to FIGS. 2 and 3 the selector ring 62 , the selection ring, which is removable from the faceplate 45 , has an interior circumferential surface 72 with a diameter that is slightly larger than the exterior diameter of the pedestal 66 . This arrangement allows the selector ring 62 to be rotated around the pedestal 66 .
[0030] With reference to FIGS. 4 and 5 , the selector ring 62 has an outer annular shell 76 that has a bore 75 within which an annular magnet retainer 78 fits and is held therein by snap tabs, adhesive or other fastening technique. The magnet retainer 78 has a plurality of apertures 80 extending between its two planar surfaces and a separate permanent magnet 82 is received within each aperture. Every permanent magnet 82 has a round shaft 83 projecting through the respective aperture 80 and a head 84 , at an interior end of the shaft, which head is held between the shell 76 and the magnet retainer 78 when those latter components are secured together. The magnet head 84 prevents the magnets from sliding completely through the apertures 80 . The opposite, exterior end of the shaft 83 of each permanent magnet 82 is exposed through the opening of the aperture 80 on a first side 85 of the selector ring 62 . There are an even number of permanent magnets 82 arranged circumferentially around the selector ring 62 with their north and south poles alternating. Specifically if the north pole of a given permanent magnet is exposed on the first side 85 of the selector ring, and the adjacent permanent magnets on both sides of that given magnet have their south poles exposed on the first side. For example, there are 24 permanent magnets spaced a 15° increments annularly around the selector ring 62 . The Hall effect sensor 58 , such as model A3425 from Allegro MicroSystems, Inc. of Worcester, Mass. 01606 U.S.A., has two active Hall effect elements spaced closer together than the magnet spacing so that only one element at a time senses a permanent magnet as the selector ring rotates around the pedestal. This enables the controller 44 to determine the direction that the selector ring 62 is rotating from the Hall effect sensor signal.
[0031] As shown in FIG. 3 , a C-shaped body 88 of magnetic material, such as steel, is embedded in the control panel faceplate 45 around the pedestal 66 . The Hall effect sensor 58 is located at the opening of that C-shaped body. In a preferred embodiment of the present invention, the C-shaped body 88 is molded into the plastic of the faceplate 45 , but alternatively it can be secured to either the inner or outer surface of the faceplate by adhesive or other fastening technique which does not penetrate entirely through the faceplate. As a result, when the selector ring 62 is placed around the pedestal 66 , many of the permanent magnets 82 are attracted to the C-shaped body 88 , thereby holding the selector ring against the faceplate 45 . Thus the same magnets 82 which are used by the Hall effect sensor 58 to detect motion of the selector ring 62 also hold that selector ring in place on the faceplate 45 . However, this magnetic attraction allows a bather to pull the selector ring 62 away from the faceplate 45 for cleaning and other purposes. Because the user control panel 14 is intended to be mounted vertically or horizontally on a shower enclosure wall, the pedestal 66 passing through the selector ring 62 also aids in holding the selector ring in place against the force of gravity.
[0032] With reference again to FIG. 2 , the exemplary information presented on the display 56 illustrates the outlet selection menu, which provides a list of the different shower heads and other water outlets in the shower enclosure. The bather is able to scroll up or down through this list by rotating the selector ring 62 counterclockwise or clockwise, respectively, about the pedestal 66 . That rotational movement is detected by the Hall effect sensor 58 to provide a signal that is sent to the controller 44 within the user control panel 14 . In response to that signal, the controller changes the item in the list of water outlets that is highlighted for selection by the bather. More than four water outlets can be scrolled through with designations of additional outlets appearing as the bath scrolls upward from the top of the list or downward from the bottom of the list.
[0033] When the desired water outlet is highlighted by reversed font, the bather indicates that desired selection by pressing the fifth momentary contact switch 55 at the center of the pedestal 66 . This turns on the solenoid valve 22 . As used herein the term “information screen” refers to the information being presented on the display 56 and not to the hardware of that display device. On the new information screen, the bather can now scroll through a number of water flow patterns to select the one that is desired for the selected water outlet, in this case the pulsing flow from the shower head. Near the upper right corner of the information screen in FIG. 6 , is an indication that by pressing the return, or fourth, momentary contact switch 54 on the user control panel, the display will return to the previous information screen, in this case the outlet selection screen shown in FIG. 2 . Other information screens, such as one for programming the preset operating configurations, can be accessed from a main system menu screen to which access is gained by pressing the return momentary contact switch 54 a sufficient number of times.
[0034] The information screen in FIG. 2 indicates that by pressing the return, or fourth, momentary contact switch 54 , a temperature control screen shown in FIG. 7 will be displayed. For this information screen, the display 56 presents the current temperature of the water flowing through the various outlets and the preset temperature that the bather has indicated previously is desired for that flow. When this information screen is presented on the display 56 , rotation of the selector ring 62 increases or decreases the preset, or desired, temperature depending upon the direction of that rotation. This designated preset temperature is conveyed from the user control panel 14 to the primary controller 12 , and particularly to the microcomputer 18 . In response, the microcomputer 18 sends data through the data interface 41 to the data interface 102 in the digital valve 100 . The valve controller 101 uses this information to alter the position of the mixing valve 21 to change the ratio of hot and cold supply water to produce a desired outlet temperature for the water sent to the individual control valves 22 . The valve controller 101 also receives a signal from the temperature sensor 25 indicating the outlet water temperature and responds to that sensor signal also by operating the mixing valve 21 to achieve the desired temperature.
[0035] With reference to FIGS. 1 and 8 , a bather also is able to initiate operation of the shower system using a hand-held, remote control 16 that transmits commands to a radio frequency (RF) receiver 30 within the user control panel 14 . The wireless remote control 16 has a pair of momentary contact switches 31 and 32 for respectively turning on and off the control system 10 and selecting from among the plurality of preset operating configurations of the shower system. The selection of a particular preset operating configuration is indicated by a plurality of light emitting diodes (LED's) 34 . The switches 31 and 32 and the light emitting diodes 34 are connected to a control circuit 36 that responds to the activation of those switches by providing a digital code to a radio frequency transmitter 38 . The radio frequency transmitter 38 modulates a radio frequency carrier signal with that digital data and transmits the resultant RF signal 40 to the radio frequency receiver 30 within the user control panel 14 .
[0036] Pressing the first momentary contact switch 31 on the remote control, alternately turns the control system 10 on and off. For example, the bather is able to turn on the shower system while in bed so that the water temperature will reach the desired level by the time the bather enters the shower enclosure. The second momentary contact switch 32 on the remote control 16 is employed to select one of the six preset operating configurations for the shower system. Repeatedly pressing the second momentary contact switch 32 through each of the six preset operating configurations with the LED's 34 indicating the number of the currently designated configuration. After the bather has illuminated the LED corresponding to the desired preset operating configuration, the bather releases the second momentary contact switch 32 . When the designation of a preset operating configuration remains unchanged for a given period of time, e.g. five seconds, the control circuit 36 sends a digital code indicating that preset operating configuration to the radio frequency transmitter 38 . That digital code then is transmitted via the radio frequency signal 40 to the RF receiver 30 within the user control panel 14 .
[0037] The RF receiver decodes the radio frequency signal 40 and extracts the digital code indicating the selected preset operating configuration which is then sent to the controller 44 . In response to the receipt of that selection, the microcomputer 18 communicate to the digital valve 100 which in turn operates the water valves 21 and 22 , the light bulbs 26 , and the audio system 28 according to the information stored previously for that selected preset operating configuration. Therefore, the remote control 16 allows the bather to set up the shower system for a desired bathing experience before entering the shower enclosure where the user control panel 14 is located.
[0038] The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure. | A user interface for controlling a plumbing fixture includes an electronic display configured to display multiple different graphical menus for controlling a plurality of valves. The user interface includes a selector control configured to receive input from a user for navigating the multiple different graphical menus and for selecting items displayed in the multiple different graphical menus. A controller receives a first user input from the selector control and causes the electronic display to switch from displaying one of the graphical menus to another of the graphical menus in response to the first user input. The controller receives a second user input from the selector control and causes the plurality of valves to make multiple different adjustments in response to the second user input based on which of the multiple different graphical menus are displayed when the second user input is received. | 4 |
CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention concerns a removable device allowing stationary swimming in an above-ground swimming pool or self-supporting swimming pool.
[0007] More precisely, the invention is attached to a device allowing stationary swimming in a water basin suitable for holding a relatively small volume of water, in particular, a swimming pool of reduced dimensions, preferable removable or above-ground.
[0008] It is especially thought to apply the invention for stationary swimming in small above-ground swimming pools, such as removable swimming pools, consisting for example of a pliable, water-proof liner that is kept in shape by a rigid or flexible peripheral structure, the invention allowing confirmed swimmers with or without flippers or beginning or still learning swimmers to move around in the middle of said swimming pools.
[0009] The invention is also applicable to the equipment of water basins or swimming pools that are intended to be used for conditioning or adaptive aquatics, under medical supervision or not, of persons recovering from an illness or an accident and for whom swimming in large swimming pools would be premature and not advisable, or even dangerous.
[0010] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
[0011] The majority of water basins allowing stationary swimming make use of tethers, being elastic or not, and tie the swimmer who is equipped with a harness or a lap belt to one or several fixed points on the rim of the swimming pool or on the bottom of the swimming pool. The invention relates to a system applying a method of this kind.
[0012] In the documents, U.S. Pat. No. 4,247,096, U.S. Pat. No. 4,577,859, U.S. Pat. No. 4,527,795, U.S. Pat. No. 6,251,049 GB-2 214 800, GB-2 382 525, WO-2002/09824, WO-2004/012827, the swimmer is either tied by a tether, elastic or not (U.S. Pat. No. 4,527,795), to a fixed point, generally by a ring incorporated into the side wall of the swimming pool or to a rigid structure that is solidly tied into one of the end sides of the swimming pool, or to the upper portion of a pole that is firmly placed into the ground outside of the water basin, thus allowing to block or to reduce the effects of progression of the swimmer in the water basin.
[0013] The devices described in the aforementioned documents apply necessarily to swimming pools built of solid and rigid materials allowing the fastening of the attachment points to the walls of said swimming pools or to a pole placed in the ground, outside of and in proximity to said pools.
[0014] The known aforementioned devices do not allow their implementation on removable pliable swimming pools, such as those formed by a pool of water supported by an inflatable ring or more generally those formed by a liner placed on the ground, the bottom surface of the liner resting directly on the ground which may not be perfectly flat.
[0015] Furthermore, swimming pools equipped with one or several hitching points on their rims present a potential source of injuries, for example, while children are playing in the water. Besides, the rims are rather unaesthetic due to the presence of auxiliary devices attached to the edge of the swimming pools.
BRIEF SUMMARY OF THE INVENTION
[0016] The invention intends to provide a simple and economical solution to the aforementioned problems which are not resolved by the methods and devices of the state-of-the-art.
[0017] According to the invention, this objective has been achieved by a device comprised of:
equipment intended to be wrapped around the body of a swimmer; and a supple, preferably elastic, retaining tether, fastened or fitted to be fastened, by means of one of its ends, to said equipment, said device being essentially remarkable because it includes also:
at least one attaching pole allowing the fastening of the other end of the retaining tether and at least one anchoring plate fastened or fitted to be fastened in a removable manner to the base of the pole. This plate has an elongate shape and a size such that a large portion of its length can be slipped beneath one of the ends of a water basin of the above-ground or the self-supporting kind, with the result that it is firmly blocked by the weight of the water contained in said basin, thereby immobilizing and stabilizing the attachment pole fastened to said plate.
[0021] This device maybe used on all swimming pools, pliable ones like those consisting of a liner, or rigid ones like the swimming pools described in the state-of-the-art or any other swimming pools, by the installation of a removable fixed point kept in place by said swimming pool.
[0022] This removable device may be used in a localized manner on the swimming pools, allowing the original aesthetic aspect of said swimming pools to be maintained without modification of their structures. Additionally, since there is no roughness on the rim or edge of the swimming pool, it is possible to forestall any risk of injury, as could occur for example when small children are playing in the water.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] The aforementioned aims, characteristics and advantages, and others still, will appear better in the following description and the attached drawings.
[0024] FIG. 1 is a schematic view and partial longitudinal sectional view of an example of execution of the swimming device implemented in a swimming pool of the self-supported type with an inflatable ring, being kept on the ground by the swimming pool.
[0025] FIG. 2 is a front elevation view of the end of the swimming pool equipped with the swimming device of the present invention.
[0026] FIG. 3 is a side elevation view of the anchoring plate of the swimming device.
[0027] FIG. 4 is a top plan view of FIG. 3 .
[0028] FIG. 5 is a rear elevation view of the anchoring plate.
[0029] FIG. 6 is a front elevation view of the attachment pole of the tether of the swimming device.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Reference to said drawings is made to describe an interesting, albeit by no means limiting, example of execution and implementation of the device according to the invention.
[0031] In the description and the claims of the present application, the term “above-ground” and the word “self-supporting” designate swimming pools that are installed on the ground S without costly preparation (no earth work), the ground being only graded and cleared of protruding roots and undesirable stones.
[0032] FIG. 1 shows a removable swimming pool above-ground 1 which is equipped with a removable device allowing stationary swimming. According to the interesting application shown, this swimming pool is of the known type comprised of a pliable watertight liner 1 a , which is maintained in its shape by an inflatable peripheral circular tube lb, resting directly on the ground S in an operating position.
[0033] The device allowing stationary swimming includes equipment 2 intended to be placed around the body of a swimmer N and which may consist of a belt, a harness, a cross belt or similar, preferably having a snap-on fastener and a supple retaining tether 3 , attached or attachable, by one of its ends provided with a snap-on fastener system, to said equipment.
[0034] The swimmer (N) is attached to one of the ends of the pliable tether 3 , byway of a large pelvic belt 2 or a harness, with a quick snap-on/off fastener, adjustable with a fastening or attachment point, on the back between the swimmer's (N) kidneys. Said belt 2 , or harness, is made of an inert material in relation to products currently used in swimming pools.
[0035] The pliable tether 3 is advantageously constituted by a tether featuring an elastic stretch capacity such as an elastic cord an elastic strap or a similar device.
[0036] According to a characteristic disposition, the device, as per the invention, also includes at least one rigid pole 4 equipped in its upper portion with at least one attachment point 5 allowing the fastening of the other end of the retaining tether 3 , and at least one anchoring plate 6 , or fitting, to be able to be fastened in a removable manner, to the base of said attaching pole.
[0037] The attachment pole 4 may be formed by a rigid tube, made for instance of aluminum, of carbon fiber or of aramide resin such as KEVLAR (™), preferably of a cylindrical shape. According to the illustrated example ( FIG. 6 ), the tube is arched in its upper portion to form two legs 7 spreading away from each other and terminating in their lower portion in two straight stumps 8 . In their upper portion, the legs 7 are connected by staggered cross members 9 a, 9 b, 9 c preferably formed by plane rectangular bars that are spaced and fastened to said legs 7 , for instance by welding, heat sealing or gluing and with one drilled hole 5 a, 5 b , 5 c in their middle.
[0038] The spaced cross-braces 9 a, 9 b, 9 c, which are associated to the holes 5 a, 5 b, 5 c respectively, serve as fixed attachment points of the retaining tether 3 .
[0039] According to the illustrated example, the actual attachment pole 4 is meant to be rigidly attached, in a removable manner, on two anchoring plates 6 .
[0040] In this case, the lower portions 8 of the legs 7 are provided with holes 10 with axes that are perpendicular to said portions and intended to allow the passage of the stem of a fastener (not shown).
[0041] Of course, the attachment pole could be constituted of a single column fixed at its base, or fitted so it can be fixed, to a single anchoring plate ( 6 ).
[0042] The anchoring plate 6 or each anchoring plate 6 may be permanently attached to the lower end of the leg or the legs 7 of the attachment pole proper 4 , or it may be attached in a removable manner to said end by any suitable fastening system and organs.
[0043] According to the illustrated example of execution, the device according to the invention comprises two anchoring plates 6 that are each attached to the lower end 8 of a leg 7 of the attachment pole 4 .
[0044] The anchoring plate 6 or each anchoring plate 6 extends laterally relative to the base of the attachment pole 4 . It is essentially constituted by a plate 12 presenting an elongated shape and a length L so that the major part I of this length can be slipped beneath one of the ends of an above-ground or self-supporting water basin so as to find itself firmly blocked in a stationary position by the weight of the water in the basin.
[0045] The anchoring plate 6 or each anchoring plate 6 comprises a plane bottom surface 12 a, and it is equipped on its upper face with means allowing its removable fastening to the lower end 8 of at least one leg 7 of the attachment pole 4 .
[0046] According to the illustrated example, each anchoring plate 6 is equipped, on its upper face, with a tube 11 located near its rear end and demarcating the part I of its length intended to be slipped beneath one of the ends of the swimming pool resting on the ground.
[0047] In assembly position, the straight lower parts 8 of the legs 7 fit into the tubes 11 of the plates 6 of the stationary swimming device, said tubes presenting a section, circular for instance, and fitting properly with the shape of the straight lower portions 8 of the legs 7 . The tubes are slightly above the section of said portions 8 of said legs 7 , thus the tubes are able to be inserted into the portions 8 of legs 7 and pulled out of the portions 8 of legs 7 without having to force the tubes. The tube 11 comprises transversal drilled holes 13 in accordance with a distance between centers that is identical to the spacing obtained by the holes 10 of the legs 7 so that the stem of a fastener, for instance of a screw and a nut, can pass through the holes 10 and the holes 13 , thereby making the pole 4 integral to the anchoring plates 6 , when the pole 4 is inserted and locked in said tubes 11 .
[0048] The tube 11 is bent backwards at a certain angle allowing, after positioning of the pole 4 , to obtain an inclination of the latter towards the outside of the swimming pool. The attachment pole is implanted in this manner now forming an obtuse angle, for instance in the order of 100° with the plate 12 .
[0049] The tube 11 may be reinforced by at least one rib 14 , located essentially in back of the tube, allowing to contain the stresses of the pole 4 and to stiffen said tube 11 .
[0050] The position of the holes 13 allows installing and fastening the pole 4 and the plates 6 in such a way that the main axis (a) of said plates finds itself located at a right angle relative to the straight line connecting the base of the two legs 7 of the pole 4 .
[0051] The anchoring plate 6 or each anchoring plate 6 may be made of a material similar to that of the pole 4 , and it may include on its upper face, a rib located in its main axis (a), this rib being executed directly by pressing or being separate, for example by welding of a plate bent in the shape of an upside down V.
[0052] The tubes 11 , serving as housings to the lower portions 8 of the legs 7 of the pole 4 , are rigidly fastened on the plane plate 12 , for instance by welding, heat sealing or gluing, and being stiffened by at least the rib 14 . The ends of the plane plate 12 forming the plate 6 feature rounded non-aggressive shapes and said plate has a shape that is tapered towards the front.
[0053] The holes 5 a, 5 b, 5 c drilled in the staggered stiffening bars 9 a, 9 b, 9 c of the pole 4 represent different fixed points 5 , enabling the attachment of the elastic retaining tether 3 at different heights, this allowing regulation of said retaining tether relative to the horizontal formed by the surface of the water contained in the swimming pool.
[0054] Regulation of the inclination of the elastic retaining tether 3 , by modifying the fixed attachment point 5 , makes it possible to adapt the swimming device to the level of proficiency of the swimmer (N) moving in the swimming pool. For excellent swimmers, the attachment of the elastic tether 3 to the pole 4 should be at the lowest anchoring point 5 c. Inversely, for beginning swimmers, the fastening of the elastic tether 3 to the pole 4 must be at the highest anchoring point 5 a which provides support for the swimmer (N). At least one intermediary fastening point 5 b allows regulating the inclination of the elastic tether depending on the different levels of the swimmers in the swimming pool.
[0055] It is obvious that the device according to the invention can be easily and quickly installed by a single person, on an above-ground swimming pool of the current self-supporting type. It suffices, as a matter of fact, after having, if applicable, pushed and blocked the lower end of the pole 4 or of the legs 7 of the pole into the anchoring plate(s) 6 , to slide this (these) elongated plate(s) 6 which extend laterally relative to the axis of the pole 4 or the legs 7 of the latter, beneath the end of the swimming pool before filling it completely with water, and to then attach the retaining tether 3 to the attachment pole and to the body hardware 2 respectively. Removal of the device is just as easy and quick. | A device for stationary swimming in an above-ground or self-supporting swimming pool includes an item of equipment intended to surround the body of a swimmer, a flexible tether fastened at one end to the item of equipment, and at least one attachment pole with at least one hitching point for fastening to the other end of the tether. The base of the attachment pole is removable manner and has at least one anchoring plate extending laterally with respect to the base of the pole. The plate has an elongate shape and a size such that a large portion of its length can be slipped beneath one of the ends of a water basin lying on the ground. The mass of water contained in the basin firmly blocks the pole, thereby immobilizing and stabilizing the attachment pole. | 4 |
BACKGROUND OF THE INVENTION
In many digital data handling devices, multi-phase clocks are utilized to control the operation of the logic contained therein. In such apparatus it is sometimes desirable to stop or halt the operation of the multi-phase clocks and to resume clock sequencing at a later time. A problem prevalent among clocks which must be stopped at the end of a given sequence is the necessity of disabling the multi-phase clock drivers after the end of the last phase in the sequence and before the start of the first phase in the next sequence. Since the multi-phase clock controls the apparatus' operation, a relatively very short time period is available for this disabling operation. The result is generally either the early termination of the last phase in a sequence or a partial enabling of the first phase of the subsequent sequence.
This problem is especially prevalent in clock networks in which adjacent phases are not underlapped, that is, clock networks in which the first phase of one sequence follows immediately behind the last phase of the preceding clock sequence. There therefore exists no larger amount of time between the last phase of one sequence and the first phase of the next sequence than exists between two adjacent phases in one clock sequence. Since the time between adjacent phases in a multi-phase clock is the smallest time increment available in most of the digital apparatus, there exists no time larger than the smallest unit of time available in which the apparatus' digital logic is able to act to disable the multi-phase clock drivers.
SUMMARY OF THE INVENTION
The present invention provides a solution to the clock stoppage problem by providing a "dead time" between the last phase of one clock sequence and the first phase of the next clock sequence only in those instances in which it is desired to hold the clock sequencing operation. In all other cases the clock sequencing proceeds in the normal manner, that is, directly from the last clock phase in one sequence to the first clock phase in the next sequence.
The present invention provides a clock sequencing apparatus for producing a plurality of clock phases in a predetermined order consisting of a multi-state digital sequential circuit having a separate state for each of the clock phases including a direct correspondence between each clock phase and the state thereof and at least one additional state for which there is no such correspondence, the arrangement being such that the state of the multi-state digital sequential circuit progressively sequences from the state associated with a first of the clock phases through the state associated with a last of the clock phases in the predetermined order and then back to the state associated with the first of the clock phases unless a clock stop signal is present, in which case progression is made from the state associated with the last of the clock phases to the state associated with the additional state and on to the state associated with the first of the clock phases instead of directly from the state associated with the last of the clock phases to the state associated with the first of the clock phases.
OBJECTS
It is an object of the present invention to provide a clock sequencer which will allow stop and restart operation without generating spurious unwanted signals.
It is another object of the present invention to provide a clock sequencer with additional holding states to allow dead time at the end of a sequence in which a stop is to occur.
It is a further object of the present invention to provide a non-underlapped clock which will decode no additional unwanted phases at the end of a sequence when a stop is to occur.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects, advantages, construction and operation of the present invention will become more readily apparent from the following description and accompanying drawings in which:
FIG. 1 is a general state diagram of a multi-state sequential circuit useful in explaining the present invention.
FIG. 2 is a schematic representation of the logical circuit embodying the present invention.
FIG. 3 is a state diagram illustrating the state switching operation of the circuit described in FIG. 2.
FIG. 4 is a timing diagram illustrating representative forms of the signals present in the circuit described in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A common means for timing the control mechanism in digital data devices is accomplished through the use of a multi-phase clock sequencing apparatus. Common among such multi-phase clock sequencing apparatus are sequencers which provide four separate phases for every clock sequence. The digital data devices control circuitry may then be controlled through the use of four sequential clock phases.
A representative time relationship of these four phases may be readily seen to reference to FIG. 4. Here the four-phase timing pulses are represented by pulses 182, 184, 186 and 188. As can be seen, the clock sequencer produces phase 1, phase 2, phase 3 and phase 4 in exact sequential order and then returns again to phase 1 for another sequence without stopping.
Although the invention described is applicable to all multi-phase clock sequencers, its operation hereinafter will be described with reference to a four-phase clock sequencer with the four phases as illustrated in FIG. 4. Of course, by proper analogy, anyone with ordinary skill in the art may take these same principles and apply them to a multi-phase clock having fewer than four phases or more than four phases. The scope of the present invention is by no means limited to a four-phase clock sequencing apparatus.
Once a multi-phase clock sequencing apparatus is desired, there exists a variety of ways of constructing same. One of the methods available for accomplishing this purpose is to construct a four-phase clock from a multi-state digital sequential circuit. The present invention is applicable to a clock sequencing mechanism constructed from a multi-state digital sequencing circuit.
In a sequential circuit the four phases may be developed by providing the circuit with four separate states, providing means of sequencing through the states in a predetermined order and by providing a decoding mechanism so that each state may be decoded as the proper clock phase.
The operation of such a multi-state digital sequential circuit can be more readily understood by reference to the state diagram of FIG. 1. In FIG. 1 the four states of the digital sequential circuit are represented as circles, phase 1 being represented by circle 10, phase 2 being represented by circle 12, phase 3 being represented by circle 14, and phase 4 being represented by circle 16. In operation, the sequential circuit sequences among the four states 10, 12, 14 and 16 and produces a one clock phase for each of the states. That is, while in state 10 the sequencing apparatus produces clock phase 1; while in state circle 12 the sequencer produces clock phase 2; while in state circle 14 the sequencer produces clock phase 3; and while in state circle 16 the sequencer produces clock phase 4. In normal running operation the sequential circuit sequences from state circle 10 to state circle 12 via line 18, to state circle 14 via line 20, to state circle 16 via line 22, and back again to state circle 10 via line 24. In this manner the four clock phases are produced in a rotating sequence, as illustrated in FIG. 4 by the timing signals 182, 184, 186 and 188.
Referring to FIG. 1, the sequential circuit, while running, will rotate from state circle 10 along line 18 to state circle 12 as long as the clock is continuously running. However, if the clock is in a not-run condition, once phase 1 is reached at state circle 10, the sequencing circuit will continually return to state circle 10 illustrated by line 25 and hold there until the not-run condition is changed to a run condition. In this manner the production of the various clock phases is inhibited while the clock sequencing apparatus is in a not-run condition.
A problem with a sequential circuit producing clock phases in this manner is the transition from a run to a stop condition. Since the sequential circuit itself is producing the clock pulses with which the control circuitry of the digital device is controlled, the sequential circuit is operating at the lowest fundamental frequency of the device. Therefore, when it is desired to stop the clock sequencing after passing through clock phase 4, that is, state circle 16 in FIG. 1, and before the occurrence of the next clock phase 1, that is, state circle 10 in FIG. 1, the only time available is the shortest amount of time known to the digital device, that is the time of one clock phase. It is, therefore, difficult to stop the control and sequencing circuits in such a short time.
That problem is corrected in the present invention by providing an additional state in the sequential circuit beyond those states required for each clock phase. Whenever it is desired to stop the sequencing of the clock, passage is made from state circle 16, which produces clock phase 4, via line 28 to state circle 26 and then from state circle 26 via line 30 back to original state circle 10. The additional state represented by state circle 26 differs from the other states of the sequential circuit in that no clock phase is produced during passage through state circle 26. However, since passage through the additional state circle 26 from state circle 16 to state circle 10, an additional clock time of the digital data device is used thereby allowing additional time for the control and sequencing circuitry of the digital data device to disable the clock drivers.
At the same time, however, the state circle 26 does not impose additional time delays on the clock sequencing apparatus when a stop condition does not exist. Since upon reaching state circle 16 in FIG. 1, the path along line 28 to state circle 26 will only occur if a stop condition exists. In all other occasions passage is made directly from state circle 16 along line 24 directly to state circle 10 where the next clock phase 1 is immediately produced. Thus, the additional state circle 26 imposes no disadvantages upon the timing or sequencing of the apparatus and does allow additional "dead time" to allow the disabling of sequencing of the clock sequencing apparatus. State circle 26, in FIG. 1, is represented as an elongated circle to illustrate the point that in actual construction of the sequential circuit the "dead time" may be represented by one state or more additional states if additional delay time or "dead time" is needed to disable sequencing operations. Therefore, state circle 26 really represents at least one additional state to the four original states in the sequential circuit.
A sequential circuit designated to implement the state diagram illustrated in FIG. 1 is shown in FIG. 2. The circuitry in FIG. 2 may be easily divided into three distinct areas. The circuitry in the middle part of FIG. 2 designated by reference number 32 and consisting of three flip-flops comprise a holding means for holding the current state of the sequential circuit. The current state of the sequential circuit may be ascertained by reference to the data contained in the three flip-flops illustrated.
The second distinct area in FIG. 2 is designated by reference number 34. This circuitry, conisting of a series of combination AND/OR gates, comprise means for controlling the state of the sequential circuit. The circuitry referred to by reference number 34 receives as its inputs the outputs from the state flip-flops 32 and an external signal indicating whether or not a clock stop operation is to occur. This circuitry is then selectively connected to the inputs to the state flip-flops 32 and control the state contained in the state flip-flops 32 upon every period of the regular occurring pulse source 38 based upon the current state in the state flip-flops 32.
The third distinct area of the circuitry described in FIG. 2 comprises the decoding means illustrated as reference number 36. This series of AND gates selectively coupled to the outputs of the state flip-flops 32 comprise a means for decoding the state of the sequential circuit as a particular clock phase and thereby creates the actual clock phase signals which are then distributed to utilization devices in the equipment being timed.
In summary, the state flip-flops 32 comprise a means for holding the current state of the sequential circuit, the state in the state flip-flops being changed and controlled by the control gates 34 based upon the current state contained in the state flip-flops 32 and, finally, the decoding gates 36 connected to the output of the state flip-flops 32 for decoding the various states of the sequential circuit as individual clock phases. The bottom row of gates indicated by reference number 40 are merely a continuation of the control circuitry of the digital data device and provide a means for disabling the output of the various clock phases conditioned upon the presence of a phase enable signal 42. These gates are illustrated only for purposes of showing how a phase enable signal may be utilized to disable the clock phase output at any given time and do not form a part of the present invention, as such. These gates are not necessary for proper utilization and function of the present invention.
The state flip-flops 32 in the sequential circuit are made up of three so-called D-type flip-flops 44, 46 and 48. These three binary flip-flops provide the capability for registering or holding eight separate states. It is necessary to hold at least eight separate states since one more state than clock phases is necessary and there are four clock phases, therefore at least five states are required and thus it is necessary to have three binary flip-flops to contain the five states. Flip-flop 44 represents state bit 0; flip-flop 46 represents state bit 1; and flip-flop 48 represents state bit 2. All three flip-flops 44, 46 and 48 are all connected to a source of regularly occurring pulses 38 which may be a free-running square wave oscillator. It determines the basic clock frequency and phase basing for the digital data device.
The D-type flip-flops also have a low level "set" input and a low level "clear" input for proper initialization of the sequential circuit upon initial start-up. The low level "set" input for flip-flop 44 is indicated by line 50; for flip-flop 46 by line 54; and for flip-flop 48 by line 56. The low level "clear" input for flip-flop 44 is indicated by line 52; for flip-flop 46 by line 56; and for flip-flop 48 by line 58. No particular interconnection of these set and clear signals is indicated in the present circuit since the proper initialization of a sequential circuit depends upon a digital data device in which the sequential circuit is implemented.
As will be indicated below, a proper state for starting the present sequential circuit will be in state 000, and therefore proper initialization would occur by pulsing lines 52, 56 and 58 momentarily to a low level and holding lines 50, 54 and 56 to a high level.
All three of the state flip-flops 44, 46 and 48 are shown as having a low level "D", or data, input. This means that whenever a low signal occurs upon that input, as indicated by line 60 for flip-flop 44; line 62 for flip-flop 46; and line 64 for flip-flop 48, upon the generation of a pulse by the oscillator 38, the flip-flops would go to a "1" or a high state, which would be indicated by a high level on the True output on the flip-flops indicated by reference number 66 for flip-flop 44; 68 for flip-flop 46; and 70 for flip-flop 48. It would also be indicated by a low level at the Not-True (complement) output of the D-type flip-flop which would be indicated in the figure as 72 for flip-flop 44; 74 for flip-flop 46; and 76 for flip-flop 48. On the other hand, if a binary "high" level was present on the lines 60, 62 or 64, when the oscillator 38 occurred, the opposite condition would be present at the outputs of the three flip-flops 44, 46 and 48. That is, the True outputs 66, 68 and 70 would be low and the Not-True outputs 72, 74 and 76 would be high.
The above description of the flip-flops 44, 46 and 48 is a logical description of the state switching of the sequential apparatus. Electrically, however, these low-level D-input flip-flops may be constructed of commonly available high-level D-input flip-flops, such as Texas Instrument Part Number TI SN 14056N. In this case, the low-level D-input logical operation is simulated by reversing the True and Not-True output designations. That is, logically designating the flip-flop manufacturer's True output as the Not-True output and logically designating the flip-flop manufacturer's Not-True output as the True output. Any further reference to the outputs of the flip-flops 44, 46 and 48 will be to the logical designation, that is, as if a low-level D-input flip-flop were utilized.
The control gating means 34 is comprised of three combination AND/OR gates, 78, 80 and 82. These AND/OR gates consist of a two-input AND circuit on one side and three-input AND circuit on the other side, the outputs from which are coupled to a single low level output OR circuit. If both inputs to the two-input AND or the three inputs of the three-input AND are simultaneously high, a low signal will be present upon the single output from the OR gate. An example of such a circuit is Texas Instrument Part Number TI SN 14057N. These three control gates are selectively connected to the low level D-input of the state flip-flops 44, 46 and 48 in order to control the next state of the sequential circuit. Gate 78 is connected via line 60 to state flip-flop 44 and thereby controls state bit 0. Gate 80 is connected via line 62 to flip-flop 46 and thereby controls state bit 1. Gate 82 is connected via line 64 to state flip-flop 48 and thereby controls state bit 2.
Both inputs of the two-input AND gate 78, that is inputs 90 and 92, are connected directly to the True output 70 of flip-flop 48. Thus state bit 0 will be set to a True condition whenever the previous state of the sequential circuit was state 4, 5, 6 or 7. On the three-input AND side of gate 78, input 84 is connected to receive a stop signal via line 114; input 86 is connected to the True input 66 of flip-flop 44, i.e., the True side of state bit 0; and input 88 is connected to the Not-True output 74 of flip-flop 46, i.e., the Not-True condition of state bit 1. These three inputs together provide that state bit 0 will be set to a True condition whenever the previous state was either 1 or 5 and a Stop condition exists.
Input 94 of the three-input AND of gate 80 is also connected to receive the stop signal via line 114; while input gate 96 is connected to the True output 66 of flip-flop 44, i.e., True output of state bit 0; and input 98 is connected to the Not-True output 76 of flip-flop 48, i.e., the Not-True condition of state bit 2. These three signals combined indicate that state bit 1 will be set to a True condition whenever the previous state was 1 or 3 and a Stop condition is present. Input 100 of the two-input AND of gate 80 is connected to the True output 66 of flip-flop 44, i.e., True side of state bit 0; and input 102 is connected to the True output 68 of flip-flop 46, i.e., True state of state bit 1. This two-input AND connected in this manner provides that state bit 1 will be set to a True condition whenever the previous state was either a 3 or a 7.
Input 104 of the two-input AND of gate 82 is connected to the Not-True output 72 of flip-flop 44, i.e., the Not-True condition of state bit 0; and input 106 is connected to the True output 70 of flip-flop 48, i.e., the True state of state bit 2. This two-input AND provides that state bit 2 will be set to a True condition whenever the previous state was either a 4 or a 6.
Input 108 of the three-input AND of gate 82 is connected to the Not-True output 72 of flip-flop 44, i.e., the Not-True condition of state bit 0; while input 110 is connected to the Not-True output 74 of flip-flop 46, i.e, the Not-True condition of state bit 1; and input 112 is connected to receive a Stop signal on line 116. This three-input AND gate indicates that state bit 2 will be set to a True condition whenever the previous state was either a 0 or a 4 and a Stop signal is present. It should be noted that the Stop signal 116 is an exact logical inversion of the Stop signal which appears on line 114. That is, whenever a Stop condition is present a Stop condition would not be present, and vice versa.
There has now been descried all of the circuitry required to make the sequential circuit necessary to perform in accordance with the state diagram illustrated in FIG. 1. A more detailed description of the exact sequencing between exact state numbers will be given later.
The decoding means indicated generally by reference number 36 consists of four three-input AND gates 115, 116, 118, and 120. An example of such circuit is Texas Instrument Part Number TI SN14058. This provides one AND gate for each of the four clock phases to be decoded. Gate number 115 decodes clock phase 1; AND gate 116 decodes clock phase 2; AND gate 118 decodes clock phase 3; and AND gate 120 decodes clock phase 4.
Input 122 of AND gate 115 is connected to the Not-True output 72 of flip-flop 44, i.e., Not state bit 0; while input 124 is connected to the Not-True output 74 of flip-flop 46; i.e., Not state bit 1; and input 126 is connected to the Not-True output 76 of flip-flop 48, i.e., Not state bit 2. Since each of the three inputs to AND gate 115 is connected to the Not-True side of the corresponding state bit, the output of AND gate 115 will be a logical high signal whenever all three state bits are 0. Therefore, AND gate 115 will decode clock phase 1 whenever state 000 (zero) of the sequential circuit is reached.
Input 128 of AND gate 116 is connected to the True output 66 of flip-flop 44, i.e., True state bit 0; while input 130 is connected to the Not-True output 74 of flip-flop 46, i.e., Not state bit 1 and input 32 is connected to the Not-True output 76 of flip-flop 48, i.e., Not state bit 2. AND gate 16 therefore will decode clock phase 2 whenever the sequential circuit reaches state 001 (one).
Input 134 of AND gate 118 is connected to the True output 66 of flip-flop 44, i.e., state bit 0, while input 136 is connected to the Not-True output 74 of flip-flop 46, i.e., Not state bit 1, and input 138 is connected to the True output 70 of flip-flop 48, i.e., state bit 2. Thus, AND gate 118 will decode clock phase 3 whenever state 101 (five) of the sequential circuits is reached.
Input 140 of AND gate 120 is connected to the Not-True output 72 of flip-flop 44, i.e., Not state bit 0; while input 142 is connected to te Not-True output 74 of flip-flop 46, i.e., state bit 1, and input 144 is connected to the True output 70 of flip-flop 48, i.e., state bit 2. Thus AND gate 120 will decode clock phase 4 whenever a sequential circuit reaches state 100 (four).
Also illustrated in FIG. 2 are a series of phase enable gates indicated generally by numeral 40, there being one for each clock phase. Although not forming a functional part of the present invention, they are included in FIG. 2 to illustrate one possible means of using a separate phase-enable signal 42 to turn ON or OFF all of the clock phases as the control circuitry in the digital data device may require. It is because of the additional state in the sequential circuit provided for in the present invention that the digital data device may disable the phase-enable signal 42 after completion of clock phase 4 and before the next clock phase 1. As mentioned, there is one phase-enable state for each of the clock phases, 146, 148, 150 and 152. Each of these gates is merely a two-input NAND gate with one of the two inputs collectively tied to the phase-enable signal 42 and the other input selectively coupled to the clock phase decoder circuits 115, 116, 118 and 120, respectively. Thus, the output of NAND gate 146 produces the logical inversion of clock phase 1; the output of NAND gate 148 produces the logical inversion of clock phase 2; the output of NAND gate 50 provides the logical inversion of clock phase 3; and the output of NAND 152 provides the logical inversion of clock phase 4.
Reference to FIG. 3 will result in a clearer understanding of the sequencing of the sequential circuit described in FIG. 2. Beginning for convenience with an initial condition of state 0 in the sequential circuit, state 0 is represented in the modified state diagram of FIG. 3 as circle 154. As noted earlier in the description, while in state 0 clock phase 1 is decoded. It can be seen that if a Stop condition is present on the signal line, that the next state introduced into the state flip-flops in FIG. 2 would be state 4. This is represented in FIG. 3 as circle 156 and would provide a decoding of clock phase 2. State 5 always follows state 4 in the sequential circuit and is represented by circle 158 and would provide a decoding for clock phase 3. State 1 always follows state 5 in the sequential circuit and is represented by circle 160 and provides the decoding for clock phase 4. Since we have now completed one sequence of clock phases 1, 2, 3, 4, the next sequence of the sequential circuit depends upon whether a Stop or Stop condition is present. If a Stop condition is present, the circuit will continue to sequence at its most rapid rate changing directly from state 1 back to state 0 which is again represented by circle 154 and another clock phase 1 is decoded. However, if a Stop condition is present, the state following state 1 would be state 3 represented by circle 162 for which no clock phase is decoded. The state always following state 3 is state 2 represented by circle 164 also for which no clock phase is decoded. Always following state 2 is original state 0 again for which a clock phase 1 is decoded. If the Stop condition is still present upon entering state 0, state 0 will continue to be repeated in the state flip-flops of the sequential circuit. Since no clock phases are decoded for states 3 and 2 represented by circles 162 and 164, additional time is allowed for the control circuitry in the digital data device to turn OFF the phase-enable signals to disable the generation of clock phase 1 upon entry back to state 0.
The signal waveforms illustrated in FIG. 4 are deemed helpful in understanding the operation of the preferred embodiment. At the top of FIG. 4 is a pulse train 166 which represents the output from a source of regularly occurring pulses connected to the clock input terminals of each of the flip-flops 44, 46 and 48 in FIG. 2. Waveforms 168, 170 and 172, respectively, represent the output signals from the state flip-flops 44, 46 and 48 when the pulses of waveform 166 are sequentially applied.
As is illustrated by the lowermost waveform 176, during the period t 1 - t 0 , the Stop signal is high so that the sequencer is in its run condition. During the period t 2 - t 1 , the sequencer has a Stop signal applied to control lead 114 in FIG. 2. Finally, at time t 2 , the Stop signal again goes high.
Indicated by reference numeral 174 are a series of octal digits, which when read from left to right, represent the sequence of states stored by flip-flops 44, 46 and 48 at various times as they are switched by the pulses from the driving oscillator. So long as the Stop signal is high, the state sequence 0, 4, 5, 1 is continuously repeated. However, at time t 1 , when the Stop signal 180 goes high the sequence changes from 0, 4, 5, 1 to 5, 1, 3, 2, 0, 0 . . . 0 until time t 2 , when the Stop signal again goes high. At that time the normal sequence 0, 4, 5, 1 is again repeated until a subsequent Stop signal is applied via line 114 to the AND/OR circuits 78 and 80.
Note that the time created by the passage through state 3 and state 2 on the way to state 0 allows time for the control circuitry of the digital data device to lower the phase-enable signal 178 thus preventing the generation of a runt clock phase 1 upon entry back into state 0. The actual generation of the clock phases is illustrated by signal 182 for clock phase 1, signal 184 for clock phase 2, signal 186 for clock phase 3 and signal 188 for clock phase 4. Note that clock phase 1 occurs during state 0, clock phase 2 occurs during state 4, clock phase 3 occurs during state 5 and clock phase 4 occurs during state 1. States 3 and 2 present a "dead time" allowing the digital data logic to turn OFF the phase enable signal 178 preventing the generation of clock phase 1 upon entry into state 0 again. No clock phase 1 is generated until the circuitry is returned to a Run condition and the phase enable is made True. Note that if the sequential circuit had not passed from state 1 to state 3 upon initiation of the Stop sequence, the circuit would have passed instead to state 0, not allowing the control logic of the digital data device time to disable the phase enable signal and allowing the possibility of a creation of a runt clock phase 1 pulse illustrated in the Figure at point A.
Thus, it can be seen that there has been shown and described a novel apparatus for providing a sequential circuit for the production of the multi-phase clock which allows a "dead time" upon clock stoppage to allow the digital data devices' control logic to disable the phase enable signals. It is to be understood, however, that various changes, modifications, and substitutions in the form of the details of the described apparatus can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims: | This invention relates to a clock sequencing apparatus which allows for clock stoppage at the end of a particular clock sequence without a false decoding of clock pulses at the beginning of what would have been the next clock sequence. This result is accomplished by providing a multi-state sequential apparatus having more states than clock phases. The apparatus will detect a stop condition on the last clock phase of a clock sequence and instead of changing to the state associated with the first clock phase of the next clock sequence, it will instead change state to one or more additional "dead time" states which will allow other logic circuitry to discontinue gating of the clock phases before the apparatus returns to the state associated with the first phase of the next clock sequence. The apparatus will then remain at the state associated with the first phase of the next clock sequence until the clock is restarted and the process is repeated. | 6 |
REFERENCE TO RELATED APPLICATION
The present application claims priority to U.S. Provisional Patent Application No. 61/699,970, filed Sep. 12, 2012, and entitled “System for Optimized Plant Growth,” which is incorporated herein by reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
This application relates to technology for plant growth, and in particular to a lighting system for optimized plant growth under controlled conditions.
Growing plants in a controlled environment is now a well-known technology. Greenhouses produce large quantities of flowers and vegetables that are distributed throughout the world. More recently, plans are being grown in yet further controlled environments, for example, where all of the light and nutrients are provided in a closed, essentially windowless structure. While such systems can use incandescent lighting, the reduced power consumption and higher efficiency of light emitting diodes (LEDs) have made those the preferred choice for “indoor” greenhouses. We use the term “indoor” herein referred to systems in which plants are grown with minimal or no exposure to ambient lighting; that is, systems in which essentially all of the light provided for plant growth is provided from artificial sources such as light emitting diodes.
One example of this technology has been implemented by Ecopia Farms. Ecopia Farms grows herbs and vegetables in soil positioned in bins on racks inside a closed building. This allows control of light, water, and nutrients. The closed environment dramatically reduces the amount of water required, while the ability to grow the produce on shelves of stacked racks dramatically reduces the square footage required to produce a given amount of produce.
BRIEF SUMMARY OF THE INVENTION
Our system for enabling controlled growth of plants in containers includes a set of linear tracks spaced apart from each other. Supporting plates position the tracks in a parallel arrangement. Each track includes an array of blue and red LEDs affixed to heat sink which can slide along the track to be positioned in a desired position to the container beneath it. A controller for the LEDs is situated between every other pair of tracks to control adjacent arrays of LEDs. The controller controls the LEDs to provide light of desired intensity and wavelength to the plants.
By making each track identical to all other tracks and making each supporting plate identical to all other supporting plates, the apparatus may be enlarged or reduced in a modular manner to an appropriate size for the configuration of the plant growth system. Positioning a light sensor in proximity to the containers and coupling it to at least some of the controllers enables adjusting the intensity and wavelength of the light from the LEDs adjusted as needed for the particular plants and stage of plant growth. In addition, if the containers are labeled with identification tags, e.g. RFID, and also providing the apparatus with a tag sensor that detects the identification tags, the system can be controlled automatically. Furthermore, in some embodiments an environmental sensor is coupled to the controller to enable the controller to control an environmental variable such as temperature or humidity. Preferably each array of light emitting diodes includes only blue and red light emitting diodes mounted on a heat sink, with a temperature sensor also mounted on the heat sink in communication with the controller.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a light emitting diode assembly for plant growth;
FIG. 2 is a perspective view of the assembly;
FIG. 3 is a diagram of an LED array strip;
FIG. 4 is a perspective view of the assembly as implemented in a typical environment;
FIG. 5 is a block diagram illustrating a controller for the system; and
FIG. 6 is a diagram illustrating network control of the plant growth line.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a top view of a light emitting diode assembly 10 used for plant growth. Shown in the diagram are a series of tracks 20 having separated side rails. Positioned within each track is an light emitting diode (LED) assembly 30 which includes strips of LEDs affixed to a heat sink 30 . The LED/heat sink assembly is preferably not affixed to the track 20 , enabling it to be positioned in the track in a desired relationship to the container beneath it. The LEDs are electrically coupled to controllers 40 disposed on the plates 50 of assembly 10 .
Each pair of tracks 20 is held in a fixed position with respect to other tracks by an intervening supporting plate 50 . The plates 50 and tracks 20 enable a modular approach to the system in which additional subassemblies consisting of a plate and a track can be added to extend the length of the assembly as needed by the particular application.
FIG. 2 is a perspective view illustrating the apparatus in more detail. As shown, the individual tracks 20 each consist of a pair of L-shaped side rails 28 mounted in opposition to each other to provide a lower surface 29 upon which the LED heat sink 30 is supported. Heat sink 30 is not affixed to the track 20 , but may be moved to and fro in the track 20 as indicated by the bidirectional arrow 32 .
Also illustrated is a strip-shaped circuit board of light emitting diodes 60 affixed to the lower surface of the heat sink 30 . In the preferred embodiment the circuit board of LEDs consists of a linear row of blue LEDs disposed in parallel to a linear row of red LEDs. Wires, not shown, couple the strip of LEDs 60 to the controller 40 . The intervening plates 50 between each pair of tracks provides an attachment surface for the controller 40 , and for tabs 22 on track 20 .
FIG. 3 illustrates the LED circuit board 62 in more detail. Arranged in a linear manner along one edge of the circuit board 62 are LEDs 70 of a first color. Along the other edge of the circuit board are LEDs 75 of a different color. Preferably the two colors are red and blue. Each circuit board of LEDs 70 , 75 also preferably includes a thyristor 80 , or other sensor, for measuring the temperature of the assembled circuit board and heat sink. This allows more careful control of the temperature of the circuit board and LEDs, enabling longer life for the LEDs. A connector 90 coupled to the LEDs and the thyristor enables electrical connections to be made between the assembly 60 and the controllers 40 .
FIG. 4 is a diagram illustrating an application for the system described in FIGS. 1-3 . As shown in the FIG. 4 a rack 100 supports a series of trays 110 in which plants are being grown. Each tray includes soil with appropriate nutrients and water added as necessary. Positioned linearly above the row of trays 110 is the apparatus 10 described in conjunction with FIGS. 1-3 . Positioned above the apparatus 10 is another row of trays 109 supported on an additional portion 120 of the frame 100 . Above that additional row of trays 109 is another LED assembly (not shown) to provide illumination to that row of trays.
A series of sensors 130 are mounted along the side rails of the frame 100 to detect the light emitted by the assembly 10 , and to detect environmental conditions in the vicinity of the apparatus. The sensors 130 are coupled to the controllers 40 to provide the controllers information about the color and intensity of the light being emitted by the strips of light emitting diodes 60 .
Generally most plants absorb primarily blue and red light. With appropriate experimental testing and calculations, the apparatus described here provides an optimal mix of wavelengths of light ranging from all blue to all red, each with a controlled intensity. For example, some plants grow best with primarily blue light at the beginning of their growth, and later predominately red light. The apparatus described here enables such control.
The sensors positioned along the trays provide information about the color of the light being received. In addition those sensors also can provide information about temperature, humidity, reflected light, carbon dioxide content, or other parameters of interest at the location of the trays with the plants. The sensors can provide feedback to control systems within the facility to raise or lower the temperature, humidity, carbon dioxide content, etc. In this manner, water use can be limited and power consumption made appropriate for the needs of the plant at the time.
Furthermore, in a preferred embodiment, an RFID tag can be added to each of the trays, and this identification sensed by an RFID sensors 160 on the frame 100 . If the RFID tag information also provides information about the content of the tray, the light color and intensity of the LED emissions can be optimized for that particular plant type, even as the trays are moved to other locations on the supporting racks.
FIG. 5 is a block diagram illustrating a control system for the apparatus illustrated in FIGS. 1-3 . As shown the bins 110 containing plants are positioned under the strips of LEDs 60 which are supported by the frame 100 . A light sensor (photo detector) 130 is positioned in proximity to the bin 110 to detect the light provided by the LEDs 60 , and relay that information over a connection 135 to a controller 40 . Depending upon the particular plants and the stage of their growth, controller 40 provide signals over bus 140 to control the color and intensity of the light by controlling the LEDs. The particular bin 110 and its contents are identified to the controller 40 by an RFID tag 150 . The RFID tag communicates with an RFID sensor 160 that provides that information to a controller 40 using a connection 165 . An environmental sensor 170 provides information to control 40 about desired environmental variables, for example, temperature, humidity, carbon dioxide, etc. By coupling controller 40 to fans, heaters, or other apparatus, the environmental conditions in the vicinity of the bins 110 can therefore also be controlled.
FIG. 6 is a diagram illustrating networking of the plant growth system, and the ability to remotely control the system. As shown there, a computer or controller is coupled to the plant growth line using the Internet. The plant growth line includes sensors that report on conditions, for example, illumination intensity or illumination color, and relay that back to the computer. The LED light engines are then controlled based on the sensed conditions. The ability to sense and control parameters, such as light intensity and color, enables the plants to be grown under optimal conditions. Such a networked lighting and sensor system is explained in more detail in our co-pending U.S. Provisional Patent Application “Networked Lighting Infrastructure for Sensing Applications,” Ser. No. 61/699,968, filed Sep. 12, 2012, the contents of which are incorporated herein by reference.
In the plant growth system described here, lighting control and sensing are provided using the techniques described in the above referenced patent application. In the plant growth system here, the sensors detect carbon dioxide levels, ambient temperature, ambient humidity, and both reflected light and light from the LED sources.
As shown in FIG. 6 a web browser-based interface enables the user to connect through the internet to view the status of the plant growth lines and their sensors, as well as control the lighting, for example, by turning lights on and off, changing their power levels, and changing their schedules. In some applications of the system described here, a database running on the computer shown in FIG. 6 , or elsewhere, stores growing condition profiles for different plant species, e.g. respective red/blue LED power levels, on/off schedules, ventilation demands, etc. Desired parameters can be set and stored in a profile so that each time a plant growth line is planted with new seedlings, the user can select the appropriate profile from the database to be used by the system. The profile can contain all operating parameters and controls the LEDs until harvest time.
In addition to using the system to control the LED illumination sources, the software enables recording data from the sensors, enabling determination of the effects of various parameters over time. This enables plant growth research. Successful results enable new, more optimal, plant growth parameters for profiles to be determined.
Of course, while above we describe the structure and system described here in terms of an application for optimized plant growth, it will be apparent that the system described can have other uses, for example, in any circumstance in which controlling light output in a manufacturing process is important. For example, in the manufacture of products where photoresist is used, controlling the color and intensity of light can provide superior results. | A system for enabling controlled plant growth of plants in containers includes linear tracks spaced apart from each other by intervening supporting plates. Each track includes an array of blue and red LEDs affixed to heat sink that can slide along the track to be positioned in a desired arrangement to the container beneath it. A controller for the LEDs is positioned between every other pair of tracks to control adjacent arrays of LEDs. The controller controls the LEDs to provide light to the plants in the containers of desired intensity and wavelength. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention refers to a process for manufacturing components in a semiconductor material wafer with reduction in the starting wafer thickness.
2. Description of the Related Art
As is known, various processes have been developed for manufacturing micro-electromechanical structures, such as micromotors or microactuators usable for finely controlling the position of heads in hard disk drivers.
According to some of these processes, both the micro-electromechanical structures (or microstructures, as referred to hereinafter) and control circuits for controlling the microstructures are made in a same semiconductor material wafer. In a known process, the microstructures are formed according to the following steps:
deposition of a sacrificial layer on the substrate of the wafer;
growth of an epitaxial layer;
definition of rotor regions and stator regions, comprising suspended portions, in the epitaxial layer; and
removal of the sacrificial layer to free the suspended portions of the rotor and stator regions.
In this way, the microstructures may be formed by processing a single face of the semiconductor wafer.
More recently, the use of two distinct semiconductor wafers has been proposed. In a first wafer, the microstructures are formed by deposition of a sacrificial layer, epitaxial growth, and definition of the rotor and stator regions described above, while a second wafer is used as a support for the microstructures. In addition, in the second wafer the control circuits for controlling the microstructures may be formed.
Before removing the sacrificial layer, the two wafers are bonded together, so that the face of the first wafer where the microstructures have been formed is set facing the second wafer. Subsequently, the substrate of the first wafer is partially removed using a mechanical process (milling), so that a residual portion of substrate is obtained having a given thickness, normally of approximately 10-100 μm. Next, trenches are formed having a such depth to reach the sacrificial layer, which is finally removed so as to free the suspended portions of the rotor and stator regions.
The process described above has, however, certain drawbacks, mainly linked to the step of milling the substrate of the first wafer. In fact, since the final thickness to be achieved is in any case small (10-100 μm), the mechanical stresses generated by the mechanical members, especially at the end of the milling step, may cause cracks in the semiconductor wafer, in particular in the rotor and stator regions, thus rendering the wafer unusable. A somewhat high number of wafers must thus be discarded, and the process, which falls short of optimal yield, is, on the whole, costly. In addition, the milling process does not enable an accurate control of the thickness of the residual portion of substrate to be obtained.
The same problem is encountered also in electrical circuits formed in a wafer of semiconductor material which, for some reason, is to be thinned.
BRIEF SUMMARY OF THE INVENTION
An embodiment of the present invention provides a process for forming components (whether electronic components or micro-electromechanical structures), that enables a reduction in the mechanical stresses acting on the semiconductor material wafer the thickness of which is to be reduced.
According to an embodiment of the present invention, there is provided a process for manufacturing components in a multi-layer wafer. The process includes the steps of providing a multi-layer wafer comprising a first semiconductor material layer, a second semiconductor material layer, and a dielectric material layer arranged between the first and the second semiconductor material layer, then removing the first semiconductor material layer, initially by mechanically thinning the first semiconductor material layer, so as to form a residual conductive layer, and subsequently by chemically removing the residual conductive layer. In one application, the multi-layer wafer is bonded to a first wafer of semiconductor material, with the second semiconductor material layer facing the first wafer, after micro-electromechanical structures have been formed in the second semiconductor material layer of the multi-layer wafer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a better understanding of the present invention, embodiments thereof are now described, purely to provide non-limiting examples, with reference to the attached drawings, wherein:
FIGS. 1 and 2 show cross-sections of two starting wafers used in an embodiment of the process according to the invention;
FIGS. 3-5 show cross-sections of the wafer of FIG. 2, in successive processing steps;
FIG. 6 shows a top plan view of the wafer of FIG. 5;
FIGS. 7-12 show cross-sections of a composite wafer in successive processing steps;
FIGS. 13 and 14 show cross-sections of two starting wafers used in a second embodiment of the process according to the invention;
FIGS. 15 and 16 show cross-sections of the wafer of FIG. 13, in successive processing steps;
FIGS. 17-20 show cross-sections of a composite wafer in successive processing steps; and
FIG. 21 shows a top plan view of the wafer of FIG. 19 .
In the ensuing description, reference will be made to the process for manufacturing a composite wafer obtained by assembling a first semiconductor material wafer incorporating encapsulated microstructures (for example, microactuators) and a second semiconductor material wafer containing control circuits for controlling the microactuators and pre-amplification circuits.
DETAILED DESCRIPTION OF THE INVENTION
According to FIG. 1, a first wafer 1 , comprising a body 2 of semiconductor material, for instance monocrystalline silicon, initially accommodates a control and pre-amplification circuit 3 , of a known type and represented in a schematic and simplified way through active and passive components. The control and pre-amplification circuit 3 is obtained via standard processing steps, which are not shown in detail.
Subsequently, an insulating layer 4 , for example BPSG, is deposited on a surface 5 of the body 2 and is excavated, then connections 7 are formed. Then, via standard steps of deposition and photolithographic definition, metal regions 6 are provided on top of the insulating layer 4 . The metal regions 6 , which have functions of electrical connection and bonding, as is explained hereinafter, are electrically connected to the control and pre-amplification circuit 3 and are preferably made using chromium-palladium.
With reference to FIG. 2, on a second wafer 8 of semiconductor material, comprising a monocrystalline substrate 9 having a thickness of, for example, 675 μm, a silicon-dioxide layer is grown, intended to form a stop layer 10 .
Next, a polycrystalline-silicon germ layer 11 (indicated by a dashed line) is deposited on top of the stop layer 10 , an then a first epitaxial layer 13 is grown, which has a preset thickness of, for example, 10 μm. At the end of the epitaxial growth, a structure is thus obtained which has two conductive regions (the substrate 9 and the first epitaxial layer 13 ) separated by a buried insulating region (stop layer 10 ). In this case, one of the conductive regions is made of monocrystalline silicon (substrate 9 ) and the other of polycrystalline silicon (first epitaxial layer 13 ). The second wafer 8 is then planarized via chemical-mechanical planarization (CMP).
Next, using standard trench etching, a first trench 15 and a second trench 16 are formed, which are circular and concentric and extend in depth until they come into contact with the stop layer 10 (FIG. 3; the shape of the trenches 15 , 16 in plan view is shown in FIG. 6 by a dashed line). The first trench 15 , which has a smaller radius, delimits a first supporting region 17 . A second supporting region 18 , having annular shape, is enclosed between the first trench 15 and the second trench 16 , and is separated from an external portion 13 a of the first epitaxial layer 13 by the second trench 16 .
Subsequently, a sacrificial layer, for example of silicon dioxide, is deposited and fills the trenches 15 , 16 , forming portions of oxide 19 , and is then selectively removed from the surface of the first epitaxial layer 13 so as to form sacrificial regions 20 and expose portions of the first supporting region 17 , portions of the second supporting region 18 , and portions of the external portion 13 a of the first epitaxial layer 13 .
After depositing a second polycrystalline-silicon germ layer (not shown), a second epitaxial layer 22 is grown (FIG. 4 ), so as to form an epitaxial region 21 including the first and second epitaxial layer 13 , 22 . The epitaxial region 21 has an overall thickness preferably of between 10 μm and 100 μm (for example, 45 μm). The second wafer 8 is then once again planarized via CMP.
Subsequently, a hard mask 23 is formed which covers the second epitaxial layer 22 except for windows 23 ′ overlying the sacrificial regions 20 , and the second epitaxial layer 22 is deeply etched—performing for example an advanced silicon etch (ASE)—which stops on the sacrificial regions 20 (FIG. 5 ). In this processing step are formed a third trench 27 , which separates a stator 29 from a rotor 30 , and a fourth trench 31 , which externally defines the rotor 30 and separates it from an external epitaxial portion 21 ′ of the epitaxial region 21 (FIGS. 5 and 6 ).
In a per se known manner, the stator 29 and the rotor 30 , connected together via spring regions 32 , have stator arms 29 a and, respectively, rotor arms 30 a , comb-fingered (FIG. 6 ). In addition, the stator 29 is anchored to first supporting region 17 , and the rotor 30 is anchored to the second supporting region 18 .
The sacrificial regions 20 are then removed through a selective etch having a preset duration, which does not remove the oxide portions 19 inside the first trench 15 and the second trench 16 . During etching, the stator arms 29 a and the rotor arms 30 a are freed, thus remaining suspended.
Subsequently (FIG. 7 ), the second wafer 8 is turned upside down, aligned and welded to the first wafer 1 (in which the control and pre-amplification circuits 3 are made) so that the stator 29 and the rotor 30 are facing the first wafer 1 . A composite wafer 35 is thus formed. In particular, the metal regions 6 made on the first wafer 1 are welded to surface portions of the stator 29 and of the external epitaxial portion 21 ′.
The substrate 9 of the wafer 8 is then removed via a process comprising at least two steps. Initially, the substrate 9 is thinned out by mechanical milling, which, according to the invention, is interrupted to leave a residual portion 9 ′ having a preset thickness D, preferably of approximately 50 μm (FIG. 8 ). The thickness D of the residual portion 9 ′ is such as to prevent the vibrations caused by the milling operation from producing cracks in the stator 19 and in the rotor 30 , in particular in the stator arms 29 a and rotor arms 30 a , which are the parts more easily subject to damage.
Subsequently (FIG. 9 ), the residual portion 9 ′ is removed via chemical etching, for example a wet etch or a plasma etch that automatically stops on the stop layer 10 (of silicon dioxide), which is exposed and protects the underlying regions (external epitaxial region 21 ′ and first and second supporting regions 17 and 18 ).
Next, through oxide etching, the stop layer 10 and the oxide portion 19 are removed. Thereby, the first supporting region 17 and second supporting region 18 are freed and rendered movable with respect to one another. Consequently, also the stator 29 (which is integral with the first supporting region 17 ) and the rotor 30 (which is integral with the second supporting region 18 ) are movable with respect to one another.
The process is then completed with known processing steps. In particular (FIG. 11 ), suspended connection lines 36 a and contact regions 36 b are formed; the body 2 of the wafer 1 is thinned by milling; and the composite wafer 35 is welded to a service wafer, for example of glass, and then cut, employing usual cutting techniques, to obtain a plurality of dice 35 ′, each of which comprises a microactuator 37 connected to a respective protection chip 38 . Finally (FIG. 12 ), the protection chip 38 is removed, and the microactuator 37 is assembled to a member that can be moved 39 a (for example, a write/read head of a hard disk) and to a supporting member 39 b (for example a suspension or gimbal).
According to a different embodiment of the invention, the process is used for obtaining a micromotor provided with a translating platform.
As shown in FIG. 13, initially a supporting wafer 40 is formed, basically as already illustrated with reference to FIG. 1 . In particular, the supporting wafer 40 comprises a semiconductor material body 41 , accommodating control circuits 42 (represented only schematically through active and passive electrical components) and an insulating layer 43 , which is etched to form contact regions 44 (shown only schematically) on top of first actuation control regions 48 , which are shorter in height than the contact regions 44 .
With reference to FIGS. 14-21, on a wafer 46 (having a thickness of between 600 μm and 700 μm, for example 675 μm) a silicon dioxide layer is deposited to form a stop layer 47 , and then an epitaxial layer 49 is grown having a thickness of, for instance, 100 μm.
Subsequently (FIG. 14 ), via a trench etch, circular trenches 50 are formed having a depth such as to come into contact with the stop layer 47 (the circular trenches 50 are shown in plan view in FIG. 21 ). In detail, each of the circular trenches 50 delimits a respective cylindrical region 51 ; the cylindrical trenches 50 are arranged at equal distances and are made along the perimeter of a square designed to house the rotor element of a linear-type micromotor the side of which measures, for example, 3 mm.
Via a thermal-oxidation step, an insulating layer 52 is then formed which covers the entire wafer 45 and, in particular, the walls of the circular trenches 50 (FIG. 15 ). Next, a conductive layer 53 is deposited, preferably of doped polycrystalline silicon, which fills the circular trenches 50 . The conductive layer 53 and the insulating layer 52 are then dry-etched, so as to be removed from a surface 54 of the epitaxial layer 49 , and subsequently wet-etched, so as to be removed from a bottom face (not shown) of the wafer 45 (FIG. 16 ).
Thereby, annular structures 58 are formed which comprise two insulating regions 52 ′, set concentrically, and an intermediate conductive region 57 . The annular regions 58 surround the cylindrical regions 51 (forming vias) and isolate them with respect to the outside world.
On top of the epitaxial layer 49 , connection regions 60 and second actuation-control regions 61 , for example of chromium-palladium, are then formed, with connection region 60 being positioned on the cylindrical regions 51 .
As shown in FIG. 17, the wafer 45 is then set upside down, aligned and welded to the supporting wafer 40 . In particular, the connection regions 60 are aligned to the contact regions 43 , thus electrically connecting the cylindrical regions 51 to the contact regions 43 and to the control circuits 42 . The first and second control regions are set facing one another, even if they are not aligned, for the reasons explained hereinafter.
Subsequently, the substrate 46 is removed. In particular, first a milling step is performed to eliminate one part of the substrate 46 and to leave a residual portion 46 ′ having a thickness D′ of approximately 50 μm (FIG. 18 ). Next, also the residual portion 46 ′ is removed, via chemical etching of the silicon, which is stopped by the stop layer 47 (FIG. 19 ). The etch may be either a wet etch or a plasma etch.
Through a photolithographic process, the stop layer 47 is selectively etched to form a mask 47 ′ (FIG. 20 ). Using this mask 47 ′, the epitaxial layer 49 is then etched, and a through trench 65 is formed which has a substantially square or rectangular shape; the mask 47 ′ is then removed. In detail, the through trench 65 has a width L 1 of, for instance, 25 μm, and delimits, within it, a platform 66 which is movable with respect to the epitaxial layer 49 ′ along two directions X, Y, parallel to the drawing sheet plane and orthogonal to one another, as a result of the forces generated by the first and second actuation control regions 48 , 61 when the latter are appropriately biased (FIG. 21 ). The platform 66 , which preferably has a square shape, with a side length L 2 of approximately 2 mm, is connected to the epitaxial layer 49 ′ via springs 67 and is surrounded at a distance by the annular structures 58 .
Finally, standard processing steps are carried out to complete a translating-platform micromotor.
The advantages of the method according to the present invention emerge clearly from the foregoing description. In particular, thanks to the presence of the stop region 10 , 47 , removal of the substrate 9 , 46 of the wafer 8 , 45 containing the microstructure (microactuator or micromotor) may be completed via a chemical etching step, thus considerably reducing any risk of cracks. The mechanical removal step (milling step) is in fact interrupted when the residual portion 9 ′, 46 ′ of the substrate 9 , 46 to be eliminated still has a large thickness and is thus able, together with the stop layer 10 , 47 , to attenuate the stresses that propagate to the parts more easily subject to cracking. Consequently, the percentage of rejects is considerably reduced and the yield of the process is high.
Furthermore, the final thickness of the wafer containing the microstructure can be controlled with very high precision. This thickness is in fact basically determined by the duration of the epitaxial growth which leads to the formation of the layers 13 , 49 and can be easily controlled using current techniques and machinery.
A further advantage lies in the fact that, after removing the stop layer 10 , 47 , the free surface of the epitaxial region has a low roughness, lower than that obtainable via planarization and polishing processes.
In addition, the stop layer 10 , 47 may be advantageously used to form a silicon-etch mask, whenever this is required.
Finally, it is clear that modifications and variations may be made to the method described herein, without departing from the scope of the invention.
For example, it is possible to manufacture the microstructure starting from a silicon-on-insulator (SOI) wafer. In this case, the microstructure is made in a monocrystalline-silicon region, which can be advantageously exploited for forming also the signal control and pre-amplification circuitry. The wafer welded to the wafer containing the microstructure performs, instead, solely a supporting function. Using an SOI substrate, the process is simplified.
As has been pointed out, the process may be used also in case of an integrated circuit formed in a wafer comprising a substrate and an epitaxial layer separated from each other by an oxide layer, in which either the substrate or the epitaxial layer is removed in a final or in an intermediate step of the process.
The bonding regions used for welding the two wafers may be of a non-conductive type; for example, they may be made of glass paste. | A process for manufacturing components in a multi-layer wafer, including the steps of: providing a multi-layer wafer comprising a first semiconductor material layer, a second semiconductor material layer (, and a dielectric material layer arranged between the first and the second semiconductor material layer; and removing the first semiconductor material layer initially by mechanically thinning the first semiconductor material layer, so as to form a residual conductive layer, and subsequently by chemically removing the residual conductive layer. In one application, the multi-layer wafer is bonded to a first wafer of semiconductor material, with the second semiconductor material layer facing the first wafer, after micro-electromechanical structures have been formed in the second semiconductor material layer of the multi-layer wafer. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Provisional Application, Ser. No. 61/404,823 filed Oct. 12, 2010
BACKROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the fields of children's bed clothes and interactive, development articles for kids.
[0004] 2. Description of the Prior Art
[0005] Children have been sleeping in beds for hundreds of years. The bedding for these beds has only served two purposes. The first to make the bed look cute or attractive when made, the second to make the child sleeping in the bed feel comfortable. The task of making the bed after sleeping in it is commonly looked upon as a chore, especially for children. Therefore most beds go unmade except for when guest come to visit or if parents are diligent in requiring their child to make the bed on a daily basis or in fact make it themselves.
[0006] The children's bedding industry has evolved from simple practical designs with very few choices to an industry saturated with color, patterns and fabric options. In recent years the industry has relied heavily upon licensing to promote sales. Characters from popular animated films as well as comic book action figures are among the most popular targets for licensing. Many children's room decor are designed with a central theme incorporating the bedding design. Parents spend an enormous amount of money on bedding for their children's first bed in order to make them feel comfortable and safe when leaving the crib. Children grow up quickly and their interests are constantly changing. The single biggest problem with children's bedding sets is that they are very age specific; therefore the average child can easily go through four of five different bedding sets by the time they reach the teen years.
[0007] Children reach the age that they no longer sleep in a crib, usually around three years old. This is when they begin sleeping in their first big boy or big girl bed. This is also the time parents begin teaching and training them to begin doing things for themselves, such as dressing, cleaning and picking up their messes, organizing their belongings and developing their personal taste.
[0008] Several blankets have been proposed over the years for providing various types of stimulation for young children. For example, U.S. Pat. No. 4,989,285 by Troncone et al. discloses a dual-layer blanket comprising two sheets of different fabrics connected only about their common peripheries, so that the interior areas of the sheets can slide over one another. This sliding effect, with appropriately chosen fabrics, simulates the tactile response of the amnion lining and amniotic fluid experienced by a fetus in utero. Also U.S. Pat. No. 6,427,265 by Julie Dix is a blanket and pillow which has various sized loops sewn to the edge for the child to interact with and be stimulated. These two articles are limited to use by very young children. Patent 6 , 601 , 250 by Larry Taylor is a bed sheet with pockets for storing a wide variety of objects and items for greater organization in a bedroom. While useful this invention has very little novelty value and is not appealing to children.
SUMMARY OF THE INVENTION
[0009] Until the creation of the present invention there has never been a comprehensive bedding system that addresses a multitude of needs of both a child and the parent. Practical needs such as extra places to put toys away or display collectable stuffed animals, as well as educational, developmental, and decorative uses all rolled into one system.
[0010] The unique, novel design and concept of the present invention is attractive to both children and adults alike. Parents are always looking for new educational and developmental tools to inspire their young children and give them a competitive edge in the world. They also go to great lengths to provide a room decor that is stimulating and creates a safe, comfortable environment for their children to thrive. All of these desires are addressed with this new bedding system, which in turn produces a great value to adults in a world where most households rely on the incomes of both parents to make ends meet.
[0011] This new interactive and customizable bedding system has multiple objectives.
[0012] The first two objectives are the same as all previous bedding ensembles, which is to make the bed look cute, and make the child sleeping in the bed feel comfortable.
[0013] The first new and original objective of this bedding system is to serve as a training tool for parents to teach, develop and reinforce basic skills and character traits to their children that they can use for the rest of their life.
[0014] The second new and original objective is to make it possible for kids to have fun when making the bed.
[0015] Another objective is to provide a fun new place for kids to store and display their favorite small toys or collectables.
[0016] It is still another objective of this invention to provide a bedding system that is customizable in a way that extends the life of the desirability of said bedding, which will in turn save families money.
[0017] Yet another objective of this bedding system is to provide a fun activity for parents and children to do together.
[0018] These objectives are attained through the relationship of and interaction with the six components of this bedding ensemble system. They are the pocketed bed skirt, duvet cover with hook strip sewn to three sides, pillow sham with hook strip sewn to two sides, matching throw pillow and window dressing, and embellishment kit (kit includes but is not limited to embroideries, two-sided belts, rhinestone appliqués, decorative interchangeable trims, mini ironing board). The six components of this revolutionary bedding system can be made from numerous types of fabric and materials, and all but the items of the embellishment kit are cut from a pattern and sewn together using the same machines and techniques used for making jeans.
[0019] Children can interact with this bedding system in many ways. Through this interaction they can develop dexterity, motor skills, learn to spell, identify objects, and be introduced to traits and concepts that will help them become independent, productive adults some day. They can also develop creative skills, individual taste, and self confidence. By practicing threading two-sided belts through the belt loops sewn on the bed skirt, and zipping the zippers up and down, a small child can develop the dexterity and motor skills needed to dress themselves as well as perform other simple task. The bed skirt is also a great tool for parents to teach their kids good habits such as putting toys away, keeping their room tidy, as well as organization and educational skills.
[0020] The task of attaching the decorative interchangeable trim pieces to the duvet cover and pillow sham is a great way for children to learn eye-hand coordination, patience and concentration skills. With unlimited trims available to use as part of this simple system, kids can change the look of their bedding whenever they want by easily changing the trims. This system also provides a way for parents to easily remove fragile and expensive trims during washing, to prevent damage to the trim.
[0021] Embroidery patches in the shape of animals, letters, numbers, as well as many other categories can be used in conjunction with hook and loop dots so that kids can decorate the bedding ensemble and parents can use them to teach kids to identify these items while decorating.
[0022] This combination of interactive tasks, and customizable features, engages children with their bedding in a new way never before accomplished by any other bedding ensemble. Children can develop a sense of pride, and a relationship with their bedding that will help parents train them to make their bed on their own. One could even go as far to say that with this bedding ensemble on your bed, making the bed can be fun!
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view of six components of the interactive bedding system, duvet cover, sham, throw pillow, pocketed bed skirt, interchangeable decorative trim, two-sided belts, embroideries placed on bed, peacock rhinestone appliqué, window dressing with hook strip sewn to bottom edge of curtain valence and drapes.
[0024] FIG. 2 is a top view of duvet cover, with interchangeable decorative trim attached.
[0025] FIG. 3 is a top view of duvet cover, with hook strip sewn to the edge of three sides, and underside of interchangeable trim, revealing sticky back loop strip.
[0026] FIG. 4A is a front view of pillow sham, with interchangeable trim attached.
[0027] FIG. 4B is a front view of pillow sham without trim, exposing hook strip sewn to two sides.
[0028] FIG. 5A is a front view of throw pillow with flower rhinestones and butterfly embroideries.
[0029] FIG. 5B is a back view of throw pillow with rhinestones ironed to back pockets.
[0030] FIG. 6A is a side view of pocketed bed skirt showing pockets, zippers, belt loops, and two-sided belt.
[0031] FIG. 6B is a perspective view of the pocketed bed skirt with two-sided belt, embroidery patches
[0032] FIG. 7 is a front view of three samples of rhinestone appliqués, horse head, peacock and musical notes, that are available for the embellishment kit.
[0033] FIG. 8 is a front view of two samples of embroidery patches, jungle animals, puppies that are available for the embellishment kit.
[0034] FIG. 9 is a perspective view of two samples of two-sided belts, animal prints, plaid & dots, that are available for the embellishment kit.
[0035] FIG. 10A is a view of the front side of three samples of decorative trim strips available for the embellishment kit.
[0036] FIG. 10B is a view of the back side of the three samples of decorative interchangeable trim strips that are depicted in FIG. 10A revealing sticky back loop strip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0038] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0039] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0040] Turning now to FIG. 1 thru FIG. 10 , the preferred embodiments of this interactive bedding system for children, according to the present invention will now be given. The options and choices for users of this innovative bedding ensemble begin at purchase. Depending on the age of the child that the bedding is for, the child can be involved in all of these choices at any time along the process. The components of the ensemble system will be available in many colors and patterns. The colors to be offered to the public have been carefully selected with the intention that they are colors that look good together. This makes it possible for the consumer to mix and match the colors of the components. The six components of the present inventions will now be described.
[0041] 1. bed skirt component comprises a vertically extending drop portion 4 , that is sewn to three edges of a rectangular shaped flat portion of material 15 , that is dimensioned to horizontally overlay a box spring. Said vertically extending drop portion extends along the vertical face of two sides and foot end of box spring and is dimensioned to extend down to a point touching or slightly above the floor. The drop portion 4 is cut from a pants pattern. The pants pattern used to make drop portion comprises buttons, rivets, zippers 14 , and pattern pieces to create belt loops 13 , front and back pockets 12 , and fabric shapes that can all be sewn together using the same machines and techniques use to make jeans. The pockets 12 provide children with a great new fun place to store and display their small collectables or toys such as stuffed animals, action figures, or any other small toy that usually ends up on the bottom of a toy box. The plurality of belt loops 13 sewn to the upper most edge of the drop serve as the means for installing any of the two-sided belts 7 , 20 , 21 provided in the embellishment kit.
[0042] 2. duvet cover 1 , is comprised of two rectangular pieces of material sewn together on three sides of a common periphery. The top material should be the same material as the bed skirt, preferably denim; the bottom material is 200 or greater thread count sheeting. The non sewn side of the duvet cover is the opening to insert comforter and is placed at the head of the bed. A ⅜″ wide hook strip 10 is sewn with double stitching to the edge of the three sewn sides of the duvet cover. Depicted in FIG. 3 this hook strip 10 is used as a fastening device for the interchangeable decorative trim 5 that have had loop strip 11 fitted to the underside. FIG. 2 shows a top view of the duvet cover 1 with interchangeable trim 5 attached.
[0043] 3. Pillow sham 2 is comprised of two rectangular pieces of material, preferably denim, sewn together on four sides of a common periphery. The bottom piece of material has an opening in the middle that a pillow can be inserted into. Referring to FIG. 4B , the left and right sides of sham have ⅜″ hook strip 10 sewn to the edge while the top and bottom edge do not. This hook strip 10 is used as a fastening device for items included in the embellishment kit. FIG. 4A depicts the front surface of the sham 2 with interchangeable trim 5 attached.
[0044] 4. Throw pillow 3 is comprised of a decorative pillow cover element and a separate stuffed pillow element. The decorative pillow cover element is designed similar to the drop portion of the bed skirt 4 , and is also cut from a pants pattern containing rivets, buttons, zipper 14 , pattern pieces to create pockets 12 , belt loops 13 , etc. and sewn together using the machines and techniques used for making jeans. The pillow cover has a zipper sewn into the top edge which provides an opening to insert a stuffed pillow and to remove said stuff pillow for washing of the pillow cover. The throw pillow functions as a decorative element in the ensemble yet can be used in the same manner as the bed skirt. FIG. 5A depicts the front surface of a throw pillow on which flower rhinestones have been ironed and the back surface is depicted in FIG. 5B .
[0045] 5. Window dressing 9 is comprised of a valence portion and two drape portions. The valence portion is cut from a pants pattern and sewn together in the same manner as previously described for the drop portion of bed skirt 4 and throw pillow 3 . The valence construction is identical to the drop portion of the bed skirt, complete with buttons, rivets, zippers, pockets and belt loops. It is hung by sliding the hanging rod through the belt loops sewn to the top edge of the valence. The two drapes have a rod loop sewn into the top edge for hanging. A ⅜″ hook strip 10 is sewn with double stitching to the bottom edge of the valence and the bottom edge of each drape. This hook strip 10 is also used as a fastening devise for the interchangeable trims and other items from the embellishment kit.
[0046] 6. Embellishment kit is customized by each user to meet his or her individual taste or interest. The elements with which the embellishment kit is comprised are, but not limited to, rhinestone appliqués, embroideries, two-sided belts and decorative trim strips. These elements are provided in many different designs and options for user to choose from to build their kit. These elements are used to customize the ensemble to the individual taste of the user and serve as training tools.
[0047] These elements of the embellishment kit are further described:
[0048] A. The rhinestones appliqués are comprised of many different shapes and colors of rhinestones that are affixed to the surface of a special heat resistant plastic. These rhinestones are arranged on the special plastic in such a way as to form a recognizable image. FIG. 7 depicts three of the many different images available. The horse head 16 , musical notes 17 , and the peacock 8 are examples of the unlimited number of images that are available for the user to select from. The undersides of the rhinestones are filled with special fabric glue. They can be attached to most surfaces of the components of the bedding ensemble by heat transfer with a household iron. The iron is preheated to its highest setting. The rhinestone appliqué is placed on the bedding with the glue side facing the fabric, in the location it is to be permanently attached. Iron is pressed onto appliqué for eight seconds, iron is removed and appliqué allowed cooling. Special plastic is then peeled away. Young children should not be allowed to do this task.
[0049] B. The interchangeable decorative trim pieces offered for the embellishment kit are comprised of a multitude of different trim styles. Jacquards, ribbons, beaded, lace, embroidered, and many more types of trim can be used. The only requirement is that the trim must have a width of at least ½″. The reason for this is that the interchangeable trim must be wide enough to cover the ⅜″ hook strip that it will be attached to. FIG. 10A depicts the front side of a ribbon lace 22 , beaded jacquard 23 , and castle pattern jacquard 24 , three of the many different styles of trims available for the embellishment kit. The trim strips are fitted with a ¼″ sticky back loop strip. This ¼″ loop strip has rubber based adhesive and is stuck to the back side of the trim piece by human hand. The loop strips are attached by adhesive as opposed to stitching to prevent interference with the decorative patterns on the front side of the trim. Rubber based adhesive is used to insure a secure bond between the back side of the trim piece and the loop strip. After a 24 hour curing time the bond becomes semi-permanent. FIG. 10B depicts the back side of the trim strips 22 , 23 , 24 shown in FIG. 10A and reveals the ¼″ sticky back loop strip 11 attached.
[0050] The ¼″ width and hand application of the sticky back loop strip to the back side of the trim piece make it possible for any trim on the market that is at least ½″ in width to be used. This hook and loop fastening system gives the consumer unlimited options to customize the bedding and allows for the removal of delicate and expensive trims when it is time to wash the duvet cover, pillow sham or window dressing. The trim strips have been cut into eight separate pieces. The length of three of the trim pieces have been cut to the same lengths as the three sides of the duvet cover with hook strip sewn on. The length of two of the trim pieces have been cut to the same length as the two sides of the pillow sham that have hook strip sewn to the edge. The last three pieces have been cut to the same length as the bottom edge of the curtain valence and two drapes that have hook strip sewn to the edge. Installing and changing the trim is so easy even a child can do it. Younger children can improve dexterity and concentration skills as well as develop patience and perseverance by learning how to install the trim. When properly installed the hook & loop fastening system is completely concealed.
[0051] C. The embroidery categories offered to the user for selection to their custom embellishment kit are limitless. Categories include but are not limited to letters, numbers and shapes, jungle animals 18 , puppies 19 , dinosaurs, planets, bugs, fish and many more. The embroideries are made with many different materials using modern embroidery machines that are computerized, which allows any picture or drawing to be converted into an embroidery. These embroideries have a loop dot stuck to the back side with rubber based adhesive. The embroideries with loop dot on the back can be attached to the hook strip 10 that is sewn to the duvet cover, pillow sham or window dressing, or use corresponding hook dot to place embroidery at any location on bedding they want. Consumer can do this as a decorative alternative to the interchangeable trim strips, or to convert the side of the bed into a bulletin board that parents can use to teach their kids to spell or practice identifying animals and other objects.
[0052] D. The Two-sided belts offered to the user for selection to their custom embellishment kit are numerous. These two-sided belts are comprised of two rectangular pieces of material with contrasting patterns sewn together on four sides of a common periphery. The approximate dimensions of this material is 2″ in width and varying lengths of 54″ 60″ and 75″. FIG. 9 depicts a cheetah-tiger print design 20 , and a plaid-polka dot design 21 . The bedding ensemble system of FIG. 1 is sporting a studded belt 7 that is a different color on each side. This double pattern construction allows for user to have the option of exposing either side of the belt. The belts are used as a decorative element to the bed skirt, window dressing, and throw pillow. This is accomplished by simply threading the belt with selected side exposed, through the belt loops sewn to previously said components. User can change the look of the bedding ensemble system by simply flipping the belt over. This task of applying the belts to the bedding ensemble is a great way to develop the dexterity in the young fingers of children. It is also creatively stimulating, and helps develop a bond and sense of pride in a child which in turn can inspire them to keep their bed made.
[0053] E. Custom ironing board with telescoping legs stands 14″ with legs retracted and 22″ at full extension. It has an iron surface of 15″×20″. It is used to iron out the wrinkles in the bed skirt as well as to iron on the rhinestone appliqués. The telescoping legs make it possible to use it on beds of varying heights.
[0054] The steps to use this interactive customizable bedding system will now be described:
[0055] The first step in this interactive, customizable bedding ensemble system is to select the colors of bedding components and window dressing. The colors of these components offered to the user have been selected with the intent that they are colors and patterns that look good together. This allows the user to mix and match the colors of the components. For example the user can select a pink duvet cover, with a turquoise bed skirt, turquoise pillow sham, pink stuff pillow and turquoise window dressing. Another option would be a magenta duvet cover with a pink bed skirt, pink pillow sham, magenta stuff pillow and a magenta window dressing. The color and pattern combinations are numerous and these options allow the user to get creative, and cater to the child's individual taste. This color selection of five of the six base components is the first step of the process.
[0056] The next step is to customize the embellishment kit. This is a fun step that kids love. They can choose from a wide assortment of rhinestone appliqués, embroideries, two-sided belts and interchangeable decorative trims to name a few. FIG. 7 thru FIG. 10 shows a few of the many samples available. This is another step that stimulates the creativity in kids and helps them discover their individuality. Kids can collect and trade the elements of the embellishment kit.
[0057] Once all of the components have been selected the next step is to iron on any rhinestone appliqués user selects. If user does not desire rhinestones this step is skipped. Rhinestones can be ironed on by merchant before user takes bedding home, or user can iron on rhinestones themselves at home. This step should only be attempted at home by kids 12 or older with adult supervision, and only by people with advanced ironing skills. Whether this is done by merchant or by user at home it is best to set the bed skirt up on a bed first in order to iron out wrinkles. Attempting to iron bed skirt on a standard ironing board is very difficult to do because of its size. It is easier to do after setting up the bed skirt onto a bed and using the custom ironing board with telescoping legs, designed specifically for this purpose. This is done in the traditional manner of placing bed skirt on to the box spring with the drop portion hanging over the edge of the box spring and resting at floor level. Before ironing on the rhinestones, the creases in the drop must be ironed out. The specially made ironing board sits on four legs, is 14 inches tall with legs retracted and 22 inches at full extension, with an ironing surface of 15″×20″. The telescoping legs allow this custom ironing board to be used for beds that sit at different height. User starts at the head of the bed lifting the bed skirt up and sliding the ironing board underneath. With this custom ironing board user can start at the head of the bed, iron a section 20″ wide at a time and work their way around the bed ironing the wrinkles out of the drop in less than 10 minutes. Once the wrinkles are removed user can select areas to iron on rhinestones. The best places to iron rhinestones on to the bed skirt are the back pockets. Any area selected should be flat and not on a seam. The ironing board should be placed under the section of bed skirt to receive the appliqué.
[0058] The appliqué is placed on the bed skirt with the plastic paper side up. The iron is preheated to high and placed directly on to the appliqué paper. User should try to cover the entire appliqué with one attempt. If the appliqué is too large divide it into two sections. Place the iron onto the first section for eight seconds then move directly to the second section for eight seconds. This process heats the glue on the back of the rhinestones. While appliqué is cooling it should be rubbed gently with a soft cloth which helps to press the rhinestones against the fabric. After it is cool the plastic paper is peeled away. The rest of the bedding components should be ironed and rhinestones appliqués attached in the same method as just described but using a standard ironing board. Once these components are ironed, they are ready to be placed on bed the in the traditional manner as shown in FIG. 1 . This figure depicts a bedding ensemble system with a peacock rhinestone appliqué 8 ironed on to the corner of duvet and a throw pillow 3 with flower rhinestone appliqués ironed on to the front side.
[0059] The next step is to decorate the ensemble with the rest of the items from the embellishment kit. Parents should perform this activity with their young children. Older children can do it with their friends. The child should be allowed to choose which trim kit to use, which two-sided belts to install, and which embroidery characters to decorate the bedding with. This can be creatively stimulating for the child, give them a sense of their own individualism, and the actual task of installing the embellishments trains their dexterity, hones concentration skills, builds their self-confidence and enhances their creativity.
[0060] The next embellishment to select and install should be the two-sided belts, for the bed skirt. It requires three of these two-sided belts to get completely around the three sides of the bed skirt. First the child must select which side of two-sided belt to have exposed. Next, starting at one corner of the foot of the bed begin threading belt no. 1 through the belt loops 13 sewn to the top edge of the bed skirt. This step is repeated on the opposite side of the bed with belt no. 2 . Next belt no. 3 which is shorter than belts 1 and 2 , should be threaded through the remaining belt loops at the foot of the bed. This activity of threading the belts through the belt loops, as well as playing with the zippers 11 and snaps on the bed skirt is one of the excellent ways younger children can develop the dexterity in their hands needed to begin dressing themselves and perform other useful task on their own.
[0061] The next step is to select and install a decorative interchangeable trim from the embellishment kit. FIG. 10A displays three samples of the many choices available. The decorative interchangeable trims are attached to the bedding components via the hook and loop system previously described. The task of installing the decorative trim is slightly more advanced than that of the belts and may be more difficult for younger children. This is an opportunity for parents to encourage teamwork among siblings, or for parents to help themselves. It is also another excellent activity that develops dexterity as well as concentration skills, patience and perseverance. If the simple directions are followed, the interchangeable trim can be attached in such a way that the hook and loop system is undetectable. It is suggested to attach the trim to the pillow sham first as a practice or warm up for the duvet cover. The bedding trim kit is first removed from the embellishment kit. Two short trim pieces approximately 20″ long FIG. 4A ; 5 are provided for the pillow sham. After the sham is filled with the correct sized pillow, the user can attach the decorative trim. Using two hands, and starting at one corner, the trim is attached a few inches at a time. Attention must be paid to completely cover hook strip with interchangeable trim, as well as attaching the trim evenly and flatly against the hook strip. Children can practice with these two short pieces on the sham before attempting the duvet cover. Prior to attaching the decorative trim to the duvet cover, the user should first check the positioning of the duvet cover on the mattress. The duvet cover should be placed evenly over the mattress. The three sides that overhang the top edge of the mattress should fall evenly around the vertical face of the mattress with the hook strip edge resting just above the top edge of the belts that have been previously installed on the bed skirt. Once the duvet cover is evenly aligned, a small amount of attention should be placed on the two corners at the foot of the bed. The natural fold that occurs at the corners of the duvet cover over-hanging the mattress at the foot of the bed, should be manipulated by hand into the naturally occurring bugle shape. This look is demonstrated in FIG. 1 ; 1 a. The duvet cover is now in the correct position to aide in the ease of trim installation, and to insure the intended finished appearance. Next the user should lay the three interchangeable trim pieces for the duvet on the floor around the bed, with the two long pieces along the sides of the bed and the one shorter piece along the end of the bed. The three pieces should be put flatly and tangle free on the floor directly adjacent to the bottom edge of the bed skirt drop. This will help child from getting tangled in the trim as they work their way around the bed. Installation should begin at the foot of the bed. It doesn't matter which side you begin, but user should start on one of the long sides first, and then move to the opposite long side next, leaving the foot of the bed for last. Older and more developed children should be able to perform the trim installation by them self. If assistance is needed, a sibling, friend or parent should only help to hold the trim in place ahead of the child, while the child works his way around the bed pressing the trim onto the hook strip sewn to the edge of the duvet cover a few inches at a time. Holding the trim in two hands, with the end of the trim aligned to the corner of the bugled fold, user begins pressing the trim against the hook strip a few inches at a time. User should maintain the bugle shape of the corner, as they begin attaching the trim following the curve. Attention should be placed on completely covering the hook strip with the trim as it is attached. User should also pay attention to attaching trim evenly and flatly to the hook strip. This is easily accomplished by only trying to attach a few inches at a time. Upon completion of the first long side, the opposite long side is attached next in the same manner. The short side at the foot of the bed is installed last. When properly installed the hook and loop fastening system is virtually undetectable. This activity trains the Childs dexterity and concentration skills, and can also be used by parents to encourage teamwork, patience, perseverance, and to develop creativity in their children.
[0062] Certain users may be ready for a nap at this point, but if not the next step is to embellish the ensemble with embroideries. User has the choice to either iron on the embroidery to make a permanent attachment, or to affix the embroidery via hook and loop dots. If the permanent method is preferred, the ironing board with telescoping legs should be used again. Hook and loop dots are suggested. The hook and loop dots are sticky back and should be made with rubber based glue. When using the hook and loop dots, user should stick the hook dots to the ensemble and stick the loop dots to the embroideries. If the child likes dinosaurs, he or she can stick dinosaur embroideries anywhere on the bedding that they want. Embroideries are available in numerous categories such as flowers, bugs, jungle animals FIG. 8 ; 18 puppies FIG. 8 ; 19 , letters FIG. 1 ; 6 and numbers, to name a few. By using the hook and loop dots, to adhere the embroideries, they can be interchanged at any whim. As the child grows older or gets new interest, they can change the embroideries to match their age or interest. Parents can also use the embroideries to teach kids to spell and identify objects.
[0063] The next step and fun activity is for users to decide what to put into the pockets 12 of their bed skirt. Items that children collect such as stuffed animals, action figures, matchbox cars or any of the small toys that usually wind up on the bottom of the toy box are great choices. Parents can use this activity to teach, and reinforce concepts to their kids like picking up after themselves, to be neat and organized, and to put things back where they belong after using or playing with it.
[0064] The last step in the process is to install the window dressing 9 . This is done by first ironing and then laying the valence out flat on the ground. Next the two-sided belt is threaded through the belt loops 13 with the side that matches the side exposed on the bed skirt belts. Once the belt is in, the curtain rod is slid through the loops behind the belt so that the rod is hidden by the belt. Once the hooks provided with rod have been attached to the wall on either side of the top portion of the window, the valence can be hung. The drapes are hung by sliding the rod through the rod pocket sewn on the top edge. The two drapes are hung from the same rod and installed directly under the bottom edge of the valence. The interchangeable trim is then installed on the valence using the same techniques as the duvet cover. Parents or older children will have to install the trim to the valence. Filling the pockets of the curtain and embellishing with embroideries by younger kids should be done prior to hanging valence.
[0065] As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
[0000] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | An interactive, customizable bedding ensemble system, with components constructed from a pants-like design concept that are used in conjunction with each other to form a system whereby parents and children can interact with the bedding ensemble system to educate, stimulate, develop, and train children in a variety of basic skills, and wherein these components incorporate design elements providing options whereby user can continuously customize the appearance of the bedding ensemble system. | 0 |
CLAIM OF PRIORITY
[0001] This application claims priority under 35 U.S.C. §119 to a Korean Patent Application entitled “Device and Method for Processing Emergency Call in Portable Terminal” filed in the Korean Intellectual Property Office on Dec. 6, 2010 and assigned Serial No. 10-2010-0123569, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a device and a method for processing an emergency call in a portable terminal.
[0004] 2. Description of the Related Art
[0005] In general, a subscriber identification module (SIM) card provided in a portable terminal stores personal information so as to provide various services, such as subscriber identification, charging, and a security function. The SIM card has been developed so that a user can freely use the mobile communication with a user's own telephone number at any place regardless different mobile communication protocols, such as the CDMA (Code Division Multiple Access) scheme or the GSM (Global System for Mobile Communication) scheme. Among the SIM cards, a subscriber identification module of the UMTS (Universal Mobile Telecommunication System) in the 3 rd generation mobile communication is referred to as the USIM (Universal Subscribe Identity Module).
[0006] Such a SIM card can be manufactured in a form of a smart card and be inserted in a portable terminal to perform an initialization process including an identification process by verifying the subscriber information stored in the SIM card. Thus, the portable terminal can be used based on only the authenticated SIM card.
[0007] A portable terminal combined with a single SIM card is generally used. However, a portable terminal combined with dual SIM cards has been recently introduced. A dual SIM card terminal, it is possible to selectively switch the SIM card during operation, so that a user can use two telephone numbers with a single terminal.
[0008] However, when an emergency call is generated in a state where the SIM card, which has been selected by the user and activated, cannot perform the communication service, it is impossible to transmit an emergency call because the portable terminal can attempt to transmit the call only through the activated SIM card. The ability to place a call during an emergency situation without repeating the call attempts is important to reduce the potential impact that a delay can have in, for example, heart-related emergency since a caller may not be aware that the terminal is unable to place a call.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention has been made to solve the above-stated problems occurring in the prior art and provides additional advantages, by providing a device and a method for processing an emergency call in a portable terminal, in which a SIM card capable of performing communication services is automatically switched and an emergency call is transmitted, regardless of a SIM card activated by a user's selection.
[0010] In accordance with an aspect of the present invention, a device for processing an emergency call in a portable terminal includes: a plurality of SIM cards; and a controller to make a control so that a SIM card capable of performing a communication service is automatically switched and the emergency call is transmitted when an emergency call transmission is generated.
[0011] In accordance with an aspect of the present invention, a method for processing an emergency call in a portable terminal includes: identifying a communication service state of an activated SIM card when a transmission of the emergency call is generated; and when the activated SIM card is in a communication service unavailable state, automatically switching to a different SIM card capable of performing a communication service and transmitting the emergency call.
[0012] Accordingly, the device and the method for processing the emergency call in the portable terminal of the present invention can effectively improve the performance of the emergency call transmission with an advantage of the portable terminal including the plural SIM cards.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is a diagram illustrating a portable terminal according to an exemplary embodiment of the present invention; and
[0015] FIG. 2 is a flowchart illustrating a process of processing an emergency call in a portable terminal according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Hereinafter, the first exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
[0017] FIG. 1 is a diagram illustrating a portable terminal according to an exemplary embodiment of the present invention. As shown, a portable terminal includes two SIM cards, i.e. a first SIM card and a second SIM card for illustrative purposes, but it should be noted that two or more SIM cards can be applied according to the teachings of the present invention. Thus, the number of SIM cards provided in the terminal should not limit the scope of the invention.
[0018] Referring to FIG. 1 , an RF unit 123 performs a wireless communication function of a portable terminal. The RF unit 123 includes an RF transmitter for up-converting and amplifying a frequency of a transmitted signal and an RF receiver for low-noise amplifying a received signal and down-converting a frequency. A data processor 120 includes a transmitter for encoding and modulating the transmitted signal and a receiver for demodulating and decoding the received signal. That is, the data processor 120 can be formed with a modem and a codec. Here, the codec includes a data codec for processing packet data, etc. and an audio codec for processing an audio signal, such as voice. An audio processor 125 reproduces a received audio signal output from the audio codec of the data processor 120 or transmits a transmitted audio signal generated in a microphone to the audio codec of the data processor 120 .
[0019] A key input unit 127 includes keys for inputting numbers and character information and functional keys for setting various functions.
[0020] A memory 130 can be formed with a program memory and a data memory. The program memory can store programs for controlling the general operations of the portable terminal and programs for making a control so that it is possible to switch to a SIM card capable of performing the communication service and transmit an emergency call when transmitting the emergency call.
[0021] A controller 110 performs the general operations of the portable terminal. In operation, when the transmission of the emergency call, for example 911 emergency call, is generated by a user, the controller 110 makes a control so that a SIM card capable of performing the communication service is automatically switched and the emergency call is transmitted. For example, when a first SIM card 170 activated by a selection of the user is in a state of the communication service incapability, the controller 110 makes a control so that the first SIM card 170 is automatically switched to a second SIM card 180 capable of performing the communication service and thus the emergency call can be transmitted through the second SIM card 180 . Similarly, when the second SIM card 180 activated by a selection of the user is in a state of the communication service incapability, the controller 110 makes a control so that the second SIM card 180 is automatically switched to the first SIM card 170 capable of performing the communication service so that the emergency call can be transmitted through the first SIM card 170 .
[0022] A camera unit 140 photographs image data, and includes a camera sensor for converting a photographed optical signal to an electric signal and a signal processor for converting an analogue image signal photographed from the camera sensor to digital data. Here, it is assumed that the camera sensor is a CCD sensor or a CMOS sensor, and the signal processor can be implemented in a Digital Signal Processor (DSP). Further, the camera sensor can be integrally or separately formed with the signal processor.
[0023] An image processor 150 performs an Image Signal Processing (ISP) for displaying an image signal output from the camera unit 140 on a display unit 160 . The ISP performs a function, such as a gamma correction, an interpolation, a spatial change, an image effect, an image scale, Auto White Balance (AWB), Auto Exposure (AE), and Auto Focus (AF). Therefore, the image processor 150 processes an image signal output from the camera unit 140 frame by frame, and outputs the frame image data in accordance with a characteristic and a size of the display unit 160 . Further, the image processor unit 150 includes an image codec, and compresses the frame image data displayed on the display unit 160 in a preset scheme or restores the compressed frame image data to the original frame image data. Here, the image codec may include a JPEG codec, an MPEG4 codec, a Wavelet codec, etc. The image processor 150 is assumed to have an On Screen Display (OSD) function and can output OSD data in accordance with a screen size displayed under the control of the controller 110 .
[0024] The display unit 160 displays an image signal output from the image processor 150 on a screen and displays user data output from the controller 110 . Here, the display unit 160 can be an LCD, and in this case, the display unit 160 can include an LCD controller, a memory capable of storing image data, and an LCD display device. Here, if the LCD is implemented in a touch screen scheme, the LCD can function as an input unit. In this regard, the display unit 160 can display keys, such as the keys included in the input unit 127 .
[0025] Hereinafter, an operation of processing an emergency call in the above portable terminal will be described with reference to FIG. 2 in detail.
[0026] FIG. 2 is a flowchart illustrating a process of processing an emergency call in the portable terminal according to an exemplary embodiment of the present invention.
[0027] Referring to FIG. 2 , when a power of the portable terminal turns on, the controller 110 detects the turn-on state of the portable terminal in step 201 , and makes a control so that each of the first SIM card 170 and the second SIM card 180 attempts a camp-on, which is a communication service available state, through a network of a service provider issuing a corresponding SIM card, in step 202 .
[0028] Thereafter, the first SIM card 170 may be in a state of the communication service unavailability and the second SIM card 180 may be in a state of the camp-on capable of performing the communication service, or the second SIM card 180 may be in a state of the communication service unavailability and the first SIM card 170 may be in a state of the camp-on capable of performing the communication service.
[0029] When the user attempts to transmit an emergency call in step 203 in which the first SIM card 170 is in a state of the communication service unavailability and the second SIM card 180 is in a state of the camp-on capable of performing the communication service, the controller 110 detects the attempt of the emergency call transmission and identifies that SIM card activated through the selection of the user in step 204 . In the present invention, when a power of the portable terminal turns on, the controller of the portable terminal makes the control so that each of two SIM cards attempts a camp-on for one or more frequencies meeting a certain reception signal strength for a service. According to the result, the controller determines that the communication is possible regarding which SIM card in a state of the camp-on.
[0030] Thus, the controller determines whether the communication of the corresponding SIM card is possible or not, according to the success or failure of the camp-on of the corresponding SIM card.
[0031] If, the camp-on attempt of the corresponding SIM card is success, the controller determines the possibility of the communication according to the camp-on success of the corresponding SIM card through the alarm such as the message informing the camp-on success notification received from the corresponding network.
[0032] That is, when the first SIM card 170 is in a state of the activation by the selection of the user, the controller 110 detects the activation of the first SIM card 170 in step 205 . The controller 110 switches the first SIM card 170 to the second SIM card 180 , which has not been activated, but is in the camp-on state capable of performing the communication service, activates the second SIM card 180 , then transmits the emergency call through the second SIM card 180 in step 207 . However, when the second SIM card 180 is in a state of the activation by the selection of the user, the controller 110 detects the activation of the second SIM card 180 in step 206 and transmits the emergency call through the second SIM card 180 , which is in the camp-on state capable of performing the communication service, in step 207 .
[0033] Alternatively, when the user attempts to transmit an emergency call in a state where the second SIM card 180 is in a state of the communication service unavailability and the first SIM card 170 is in a state of the camp-on capable of performing the communication service, the controller 110 detects the attempt of the emergency call transmission and identifies the SIM card activated through the selection of the user.
[0034] When the second SIM card 180 is in a state of the activation, the controller 110 detects the activation of the second SIM card 180 in step 205 . Then, the controller 110 switches the second SIM card 180 to the first SIM card 170 , which has not been activated, but is in the camp-on state capable of performing the communication service, and activates the first SIM card 170 , then transmits the emergency call through the first SIM card 170 . However, when the first SIM card 170 is in a state of the activation by the selection of the user, the controller 110 detects the activation of the first SIM card 170 and transmits the emergency call through the first SIM card 170 which is in the camp-on state capable of performing the communication service.
[0035] In FIG. 2 , the operation of the transmission of the emergency call in the portable terminal including the first SIM card and the second SIM card has been exemplified for description. However, when the SIM card activated by the selection of the user is in the communication unavailable state, a portable terminal including two or more SIM cards also can identically perform the automatic switching to a different communication available SIM card as described above, then activate the switched SIM card for transmission of the emergency call.
[0036] Note that the above-described methods according to the present invention can be realized in hardware or as software or computer code that can be stored in a recording medium such as a CD ROM, an RAM, a floppy disk, a hard disk, or a magneto-optical disk or downloaded over a network, so that the methods described herein can be executed by such software using a general purpose computer, or a special processor or in programmable or dedicated hardware, such as an ASIC or FPGA. As would be understood in the art, the computer, the processor or the programmable hardware include memory components, e.g., RAM, ROM, Flash, etc. that may store or receive software or computer code that when accessed and executed by the computer, processor or hardware implement the processing methods described herein.
[0037] While the present invention has been shown and described with reference to certain exemplary embodiments and drawings 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 spirit and scope of the invention as defined by the appended claims. | Disclosed is a device and a method for processing an emergency call in a portable terminal regardless of a SIM card activated by a user's selection. The device includes a plurality of SIM cards, and a controller to make a control so that a SIM card capable of performing a communication service is automatically switched and the emergency call is transmitted when an emergency call transmission is generated. | 7 |
BACKGROUND OF THE INVENTION
[0001] This invention is directed to spunbond-meltblown-spunbond (“SMS”) laminates having a good softness, drape and extensibility, in addition to strength and barrier.
[0002] SMS laminates are disclosed in U.S. Pat. No. 4,041,203 to Brock et al. The laminates disclosed in Brock et al. contain two outer thermoplastic spunbond layers having an average filament diameter in excess of 12 microns, and an inner thermoplastic meltblown layer having an average fiber diameter up to 10 microns. The layers are positioned in a laminar surface-to-surface relationship and united together at intermittent discrete bond regions formed by the application of heat and pressure to provide a unitary structure. The laminates have a desirable textile-like appearance and drape characteristics, load bearing and bacterial barrier properties, and allow sterilant penetration.
[0003] SMS laminates have since been-disclosed in which some or all of the layers are formed using bicomponent filaments or fibers. Such laminates are disclosed in U.S. Pat. No. 6,776,858 to Bansal et al.; U.S. Pat. No. 6,723,669 to Clark et al.; and U.S. Publication 2004/0192146 to Sturgill II, for instance. There is a demand for SMS laminates having improved fabric properties, in addition to strength and barrier.
SUMMARY OF THE INVENTION
[0004] The invention is directed to a nonwoven fabric, specifically a SMS laminate, including:
[0005] a) an inner layer of biconstituent meltblown fibers including about 25-85% by weight of first fibers including at least 50% by weight polyolefin and about 15-75% by weight of second fibers including at least 50% by weight polyester; and
[0006] b) two outer layers of bicomponent spunbond fibers having a fiber denier of not more than about 1.1, the spunbond fibers including an outer sheath including at least 50% weight of a first polyolefin and an inner core including at least 50% by weight of a second polyolefin or a polyester.
[0007] In one embodiment, the fine bicomponent spunbond fibers include an outer sheath formed of a random propylene-ethylene copolymer containing up to 10% by weight ethylene, and an inner core formed of polypropylene homopolymer. The biconstituent meltblown fibers include first fibers formed of polypropylene and second fibers formed of polybutylene terephthalate.
[0008] In another embodiment, the fine bicomponent spunbond fibers include an outer sheath of polyethylene and an inner core of polyethylene terephthalate. The biconstituent meltblown fibers include first fibers formed of polyethylene and second fibers formed of polyethylene terephthalate.
[0009] The above combinations of fine bicomponent fiber spunbond layers and a biconstituent fiber meltblown layer produce SMS fabrics with improved strength, barrier, softness and extension properties. The fine bicomponent fiber spunbond layers contribute to improved strength, softness, and drape. The combination contributes to barrier and extension properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic fragmentary perspective view of a SMS material, with sections broken away to reveal all of the layers.
[0011] FIGS. 2A and 2B illustrate sectional views of different embodiments of a sheath-core bicomponent fiber, which can be employed in the spunbond layers of the inventive SMS laminate.
[0012] FIG. 3 illustrates a sectional view of first and second meltblown fibers having different polymer compositions, which can be employed in the meltblown layer of the inventive SMS laminate.
[0013] FIG. 4 is an enlarged sectional view showing a bond point 56 of FIG. 1 .
[0014] FIG. 5 schematically illustrates a process for preparing a SMS laminate of the invention.
DEFINITIONS
[0015] As used herein the term “nonwoven fabric or web” means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from many processes such as for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of nonwoven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and the fiber diameters useful are usually expressed in microns (μm). (Note that to convert from osy to gsm, multiply osy by 33.91).
[0016] As used herein, “denier” refers to the weight in grams per 9000 meters of an individual filament or fiber.
[0017] As used herein the term “spunbond fibers” refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appel et al.; U.S. Pat. No. 3,692,618 to Dorschner et al.; U.S. Pat. No. 3,802,817 to Matsuki et al.; U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney; U.S. Pat. No. 3,502,763 to Hartman; and U.S. Pat. No. 3,542,615 to Dobo et al. Spunbond fibers are generally not tacky when they are deposited onto a collecting surface. Spunbond fibers are generally continuous.
[0018] As used herein the term “meltblown fibers” means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al. Meltblown fibers are microfibers which may be continuous or discontinuous, and are generally tacky when deposited onto a collecting surface. “First” meltblown fibers and “second” meltblown fibers refer to meltblown fibers having different polymer compositions.
[0019] As used herein the term “polymer” generally includes but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible geometrical configurations of the molecule. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
[0020] As used herein, the term “multicomponent fibers” refers to fibers that have been formed from at least two component polymers, or the same polymer with different properties or additives, extruded from separate extruders but spun together to form one fiber or filament. Multicomponent fibers are also sometimes referred to as conjugate fibers or bicomponent fibers, although more than two components may be used. The polymers are arranged in substantially constantly positioned distinct zones across the cross-section of the multicomponent fibers and extend continuously along the length of the multicomponent fibers. The configuration of such a multicomponent fiber may be, for example, a concentric or eccentric sheath/core arrangement wherein one polymer is surrounded by another, or may be a side-by-side arrangement, an “islands-in-the-sea” arrangement, or arranged as pie-wedge shapes or as stripes on a round, oval or rectangular cross-section fiber, or other configurations. Multicomponent fibers are taught in U.S. Pat. No. 5,108,820 to Kaneko et al. and U.S. Pat. No. 5,336,552 to Strack et al. Conjugate fibers are also taught in U.S. Pat. No. 5,382,400 to Pike et al. and may be used to produce crimp in the fibers by using the differential rates of expansion and contraction of the two (or more) polymers. For two component fibers, the polymers may be present in ratios of 75/25, 50/50, 25/75 or any other desired ratios. In addition, any given component of a multicomponent fiber may desirably comprise two or more polymers as a multiconstituent blend component.
[0021] As used herein, the term “multiconstituent fibers” or “multiconstituent web” refers to a mixture of two or more different fiber types in a single nonwoven web. For instance, multiconstituent meltblown fibers, or a multiconstituent meltblown web, may include a plurality of first meltblown fibers having a first polymer composition and a plurality of second meltblown fibers having a second polymer composition different from the first. Multiconstituent fibers or webs may be referred to as biconstituent fibers or webs where the number of fiber types is two. A suitable process for making multiconstituent meltblown fibers is described in U.S. patent application Ser. No. 10/743,860, filed on 23 Dec. 2003, the disclosure of which is incorporated by reference.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to the drawings, FIG. 1 shows a SMS laminate 48 including top and bottom layers 50 and 52 of substantially continuous and randomly deposited spunbond fibers and a middle layer 54 of meltblown microfibers. The layers are joined together at a plurality of bond points 56 .
[0023] Referring to FIGS. 2A and 2B , the top and bottom spunbond layers 50 and 52 are formed of fine, sheath-core type bicomponent fibers 60 , each having an outer sheath portion A and an inner core portion B. The sheath and core may be concentric as shown in FIG. 2A , or eccentric as shown in FIG. 2B . The sheath portion A and core portion B generally extend the length of each substantially continuous spunbond fiber 60 .
[0024] The spunbond fibers 60 typically have a circular cross-section, but may have an elliptical, triangular, square, rectangular or other cross-sectional shape. The spunbond fibers 60 are fine, and of small denier, compared to typical spunbond fibers. The spunbond fibers 60 in each layer 50 and 52 may have, on average, a fiber denier of not more than about 1.1, or not more than about 1.0, or not more than about 0.9, or not more than about 0.8, or not more than about 0.7, or not more than about 0.6. The spunbond fibers 60 in each layer 50 and 52 may have, on average, a fiber denier of at least about 0.1, or at least about 0.2, or at least about 0.3, or at least about 0.4, or at least about 0.5.
[0025] The outer sheath portion A of each spunbond fiber 60 includes a first polyolefin having a first melting point, as determined by differential scanning calorimetry. Suitable sheath polymers include without limitation branched low density polyethylene homopolymers and copolymers containing up to 20% by weight of an alpha-olefin comonomer having 3-20 carbon atoms; linear low density polyethylene copolymers containing 1-20% by weight of an alpha-olefin comonomer having 3-20 carbon atoms; ethylene-propylene elastomers containing over 10% to less than 80% by weight ethylene and over 20% to less than 90% by weight propylene; propylene-ethylene random copolymers containing up to 10% by weight (suitably 2-8% by weight) ethylene and at least 90% by weight (suitably 92-98% by weight) propylene; other copolymers and terpolymers of ethylene with alpha-olefins having 3-20 carbon atoms; atactic and syndiotactic polypropylene; and combinations thereof. The first polyolefin may be formed using a Ziegler-Natta, single-site or other suitable catalyst, and may have a density of about 0.860 to less than 0.935 grams/cm 3 . The sheath portion A may include at least 50% by weight of the first polyolefin, or at least 75% by weight, or about 90-100% by weight.
[0026] The inner core portion B of each spunbond fiber 60 includes a second polyolefin or polyester having a second melting point higher than the first melting point, as determined by differential scanning calorimetry. Suitable core polymers include without limitation high density polyethylene (typically a linear ethylene homopolymer or ethylene-alpha olefin copolymer having a density of about 0.935-0.965 grams/cm 3 ); substantially isotactic polypropylene (typically a homopolymer having at least about 80% isotacticity); polyethylene terephthalate, polybutylene terephthalate; and combinations thereof. The second polyolefin or polyester may be formed using any suitable catalyst. The inner core portion B may include at least 50% by weight of the second polyolefin or polyester, or at least 75% by weight, or about 90-100% by weight.
[0027] In a first embodiment, the sheath portion A of the spunbond fibers 60 is formed of a random propylene-ethylene copolymer containing at least 90% by weight propylene, suitably 92-98% by weight, or 95-97% by weight; and up to 10% by weight ethylene, suitably 2-8% by weight, or 3-5% by weight. The propylene chains are substantially isotactic. The core portion B is formed of substantially isotactic polypropylene homopolymer. In a second embodiment, the sheath portion A of the spunbond fibers 60 is formed of branched or linear low density polyethylene. The core portion B is formed of polyethylene terephthalate.
[0028] The spunbond fibers 60 may contain about 10-90% by weight sheath portion A and about 10-90% by weight core portion B, suitably about 20-80% by weight sheath portion A and about 20-80% by weight core portion B, or about 30-70% by weight sheath portion A and about 30-70% by weight core portion B, or about 40-60% by weight sheath portion A and about 40-60% by weight core portion B.
[0029] Referring to FIGS. 1 and 3 , the middle biconstituent meltblown layer 54 of laminate 48 is formed of meltblown fibers 70 including a plurality of first meltblown fibers 70 C and a plurality of second meltblown fibers 70 D having different polymer compositions. The meltblown fibers 70 may be generally discontinuous in length, or may be substantially continuous. The meltblown fibers 70 typically have a circular cross-section, but may have an elliptical, triangular, square, rectangular or other cross-sectional shape. The meltblown fibers 70 may have an average fiber denier of not more than about 0.5, or not more than about 0.4, or not more than about 0.3, or not more than about 0.2, or not more than about 0.1. The meltblown fibers 70 may have an average fiber denier of at least about 0.01, or at least about 0.02, or at least about 0.03, or at least about 0.04, or at least about 0.05.
[0030] The first meltblown fibers 70 C include a polyolefin. Suitable polyolefins include without limitation branched low density homopolymers and copolymers containing up to 20% by weight of an alpha-olefin comonomer having 3-20 carbon atoms; linear low density polyethylene copolymers containing 1-20% by weight of an alpha-olefin comonomer having 3-20 carbon atoms; ethylene-propylene elastomers containing over 10% to less than 80% by weight ethylene and over 20% to less than 90% by weight propylene; propylene-ethylene random copolymers containing up to 10% by weight (suitably 2-8% by weight) ethylene and at least 90% by weight (suitably 92-98% by weight) propylene; other copolymers and terpolymers of ethylene with alpha-olefins having 3-20 carbon atoms; atactic and syndiotactic polypropylene; and combinations thereof. High density polyethylene and substantially isotactic polypropylene may also be suitable in some circumstances. The polyolefin may be produced using a Ziegler-Natta catalyst, a single-site (e.g. metallocene or constrained geometry) catalyst, or any other suitable catalyst. The first meltblown fibers 70 C may include at least 50% by weight of the polyolefin, or at least 75% by weight, or about 90-100% by weight.
[0031] The second meltblown fibers 70 D include a polyester. Suitable polyesters include without limitation polyethylene terephthalate, polybutylene terephthalate (otherwise known as polytetramethylene terephthalate), and combinations thereof, made using any suitable catalyst. The second meltblown fibers 70 D may include at least 50% by weight of the polyester, or at least 75% by weight, or about 90-100% by weight.
[0032] In a first embodiment, the first meltblown fibers 70 C are formed of polypropylene homopolymer or a random propylene-ethylene copolymer containing up to 10% by weight ethylene. The propylene chains in either polymer may be substantially isotactic. The second meltblown fibers 70 D are formed of polybutylene terephthalate. In a second embodiment, the first meltblown fibers 70 C are formed of branched or linear low density polyethylene. The second meltblown fibers 70 D are formed of polyethylene terephthalate.
[0033] The meltblown fibers 70 may contain about 25-85% by weight of the first meltblown fibers 70 C and about 15-75% by weight of the second meltblown fibers 70 D, suitably about 40-80% by weight of the first meltblown fibers 70 C and about 20-60% by weight of the second meltblown fibers 70 D, or about 50-75% by weight of the first meltblown fibers 70 C and about 25-50% by weight of the second meltblown fibers 70 D. In the first embodiment described above, meltblown fibers 70 may include about 75% of the first meltblown fibers 70 C and about 25% by weight of the second meltblown fibers 70 D. In the second embodiment described above, meltblown fibers 70 may include about 50% by weight of the first meltblown fibers 70 C and about 50% by weight of the second meltblown fibers 70 D.
[0034] Depending the end use application, the SMS laminate 48 may have a basis weight of about 10-300 grams per square meter (gsm), or about 15-200 gsm, or about 20-100 gsm, or about 25-50 gsm. Each of the spunbond and meltblown layers 50 , 52 and 54 may constitute about 5-60% of the weight of the SMS laminate, or about 15-50% of the weight of the laminate, or about 20-40% of the weight of the laminate, with three layers together constituting 100% of the SMS laminate.
[0035] The layers 50 , 52 and 54 can be joined together to make the SMS laminate 48 using techniques familiar to persons skilled in the art. One such technique is described in U.S. Pat. No. 4,041,203 which is incorporated by reference. Referring to FIG. 5 , the meltblown web 54 is prepared by extruding meltblown polymer fibers 182 from a die 24 onto a forming belt 26 driven by rolls 28 . High velocity air, driven in part by suction valve 30 , directs the fibers 70 toward the belt 26 . Spunbond webs 50 and 52 unwind from rolls 30 and 32 and contact both sides of meltblown web 54 in the vicinity of nip rolls 34 and 36 (which may be heated), whereupon the layers are joined together. The resulting precursor laminate 47 is passed around heated patterned bonding roll 42 , aided by guide rolls 40 and 46 , and is bonded with the aid of pressure at a nip junctions defined by patterned roll 42 and nip roll 44 , to form the SMS laminate 48 . Referring to FIG. 4 , each of the bond points 56 of SMS laminate 48 has depressed bond regions 20 adjacent to and between raised regions 12 and 14 . The spunbond and meltblown layers can be formed and joined using an in-line process as described in U.S. Pat. No. 4,041,203, or any suitable alternative process. Any of the spunbond and meltblown layers may be formed in-line. The layers may be sequentially laid over each other and bonded.
[0036] In order to prepare a SMS fabric in the manner illustrated in FIG. 5 which possesses the combination of desirable strength characteristics and textile-like drapability, it is necessary that the spunbond webs 50 and 52 be integrated with the meltblown web 54 without an accompanying adverse effect on the drapability. To this end, it is important that the bonding conditions (temperature, pressure, and to a lesser degree, dwell time in the nip) as well as the pattern of bonding be appropriately selected. An intermittent bond pattern is suitably employed with the pattern being substantially regularly repeating over the surface of the web. The pattern of the raised points on the roll 44 is selected such that the area of the web occupied by the bonds after passage through the nip is about 5-50% of the surface area of the material with the discrete bonds being present in about 50-1000/in. 2 Suitably, the bonds occupy about 10-30% of the surface area and are present in a density of about 100-500/in. 2
[0037] Regarding the bonding conditions, the bonding may have the two-fold effect of achieving ply attachment between the three layers and integrating the spunbond webs into the meltblown web so that the resulting material has desirable strength characteristics. It is believed that the illustrated construction containing a meltblown web in laminar contact with two spunbond webs allows the meltblown web to function in this two-fold capacity when at least one polymer of the meltblown web has a lower softening point than at least one polymer of the spunbond webs.
[0038] Bonding temperatures and pressures may vary according to the polymers employed in the spunbond and meltblown layers, and may be optimized according to techniques known in the art. Bonding roll temperatures may range from about 90-200° C., or from about 100-180° C., for the materials useful in making the SMS laminates of the invention. Bonding pressure may range from about 3500-35,000 Newtons/cm 2 , suitably about 4000-10,000 Newtons/cm 2 , based on pressures at the high points of the bonding roll 42 in contact with nip roll 44 .
EXAMPLES
Example 1
[0039] A SMS laminate having a basis weight of 62.8 gsm was prepared from two outer spunbond layers composed of 1.0 denier sheath/core bicomponent fibers having an outer sheath of random propylene-ethylene copolymer and an inner core of polypropylene homopolymer, and an inner biconstituent meltblown layer composed of first meltblown fibers of polypropylene homopolymer and second meltblown fibers of polybutylene terephthalate. The bicomponent spunbond fibers contained 50% by weight of random propylene-ethylene copolymer, type 6D43, available from Dow Chemical Co., and 50% by weight of polypropylene homopolymer, type 3155, available from Exxon-Mobil Co. Each spunbond layer constituted 38% by weight of the SMS laminate. The biconstituent meltblown fibers contained 75% by volume of polypropylene homopolymer, type PF-105, available from Basell Co., and 25% by volume of the polybutylene terephthalate, type CELANEX EF-NAT2008, available from Ticona Co. The meltblown layer constituted 24% by weight of the SMS laminate. The SMS layers were bonded together at a temperature of 149° C. and a pin bonding pressure of 55,158 N/cm 2 to yield a laminate having a wire-weave bond pattern and a bond area covering 17% of the laminate.
[0040] The SMS laminate was tested for hydrohead (resistance to water penetration) and tensile strength in the cross direction. The hydrohead resistance was 80.1 mbar. The tensile strength was 12.3 kg.
Example 2 (Comparative)
[0041] A commercial surgical gown sold under the trade name AURORA by Medline Industries of Mundelein, Ill., has a SMS construction with a total basis weight of 64 gsm and a meltblown layer basis weight of 17 gsm. The SMS material is sold under the trade name SUPREL by DuPont Nonwovens Co. of Old Hickory, Tenn. The meltblown layer was formed of side-by-side bicomponent fibers, each fiber having a first polyethylene side and a second polyester side. The spunbond layers were formed of sheath/core bicomponent fibers having an outer polyethylene sheath and an inner polyester core.
[0042] The gown material was found to have a hydrohead resistance of 83.5 mbar, and a CD grab peak load (grab tensile strength) of 11.1 kg.
Test Procedures
[0043] Hydrohead: Hydrohead values are measured generally according to the Hydrostatic Pressure Test described in Method 5514 of Federal Test Methods Standard No. 191A, which is equivalent to AATCC Test Method 127-89 and INDA Test Method 80.4-92, and which is incorporated herein by reference. The following additional parameters are pertinent. The hydrohead method utilizes a TEXTEST FX3000 Hydrostatic Head Tester (available from Schmid Corp., Spartanburg, S.C.) filled with purified water and maintained at a temperature between 65° F. and 85° F. (18.3 and 29.4° C.). Under the dynamic conditions, the specimens are subjected to a steadily increasing pressure of the low surface tension liquid. The rate of increase is 60 mbar/minute and the maximum pressure tested is 300 mbar (4 psi). The “strikethrough resistance” is expressed as the pressure when the liquid penetrates the sample. The test is completed after three areas of the fabric have had liquid penetration.
[0044] Tensile: The tensile strength of a fabric may be tested as grab tensile strength measuring the cross-directional grab peak load (the maximum load before the specimen ruptures) in accordance with ASTM D5034-90, using rectangular 4-inch by 6-inch (100 mm by 150 mm) specimens. The peak strain as a percentage of specimen extension at rupture may also be recorded.
[0045] While the embodiments of the invention described herein are illustrative, various modifications and improvements can be made without departing from the spirit and scope of the invention. The scope of the invention is indicated by the appended claims, and all changes that fall within the meaning and range of equivalents are intended to be embraced therein. | Spunbond-meltblown-spunbond nonwoven fabrics having good softness, drape and extensibility, in addition to strength and barrier, are formed from combinations of bicomponent spunbond fibers having low fiber denier and biconstituent meltblown fibers. The spunbond fibers include an outer sheath portion formed using a first polyolefin and an inner core portion formed using a second polyolefin or polyester. The meltblown fibers include first meltblown fibers formed using a polyolefin and second meltblown fibers formed using a polyester. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention is generally related to floating structures offshore for oil and gas production and, more particularly, to a riser keel joint assembly for such structures.
[0003] 2. General Background
[0004] All floating systems used by the Oil and Gas Industry to recover hydrocarbons from seafloor sites in offshore waters have risers of some type connecting the well termination at the seafloor to the floating system at the surface. One particular type of riser, the independently supported, top-tensioned riser, extends vertically from the seafloor to the floating system and is directly supported either by buoyancy modules (cans) or other means (e.g., tensioners) that can support the weight of the riser and accommodate the relative movement between that riser and the floating platform when the platform responds to metocean environments. This type of riser has been used by both Spar platforms and Tension Leg Platforms. Where the platform hull is a mono-column-or these risers pass close by the hull structure, some kind of special section of riser is required at the keel of the hull to accommodate the bending loads where the riser leaves the support of the platform and this section also has to accommodate the relative vertical movement between the riser and the hull.
[0005] The special riser joint at the keel of the hull and which is addressed by this invention is commonly referred to as the Keel Joint. This section is reinforced to carry the bending loads imposed on the riser by the pitch/heel motions of the hull relative to the riser as well as the bearing and wear loads imposed on the riser by the vertical and lateral motions of the hull relative to the riser.
[0006] The functions of a keel joint are straightforward and include:
[0007] Reinforcing the bending capacity of the riser by a significant amount so it can have adequate strength and adequate fatigue life (lower stress ranges).
[0008] Permitting the riser pipe to curve compliantly as the hull keel moves horizontally relative to the fixed end of the riser at the seafloor.
[0009] Bearing on the guides in the hull both to transfer the load to the hull through the keel joint outer surface, instead of through the riser pipe itself, and to incur the wear from friction forces as the riser slides axially against the guides in the hull.
[0010] There are several versions of keel joints in the known art.
[0011] One type has a larger diameter sleeve, centralized around the riser pipe and attached directly to it with rubber spacers at each end which are vulcanized to both the riser and the sleeve in the annular space. This type of joint supports the riser at the two locations of the rubber and delivers the lateral load from these two locations through the sleeve to the guide locations(s). The rubber provides the flexibility for the riser itself to rotate. In this version, the keel joint is an integral part of the riser string itself.
[0012] Another type has the riser in a sleeve similar to the above type but the sleeve is attached to the riser by bolting at each end. For this purpose, the riser is fabricated with machined bumps and flanges at each end both to attach to the sleeve and to the continuing sections of riser at each end. Riser rotation is limited by the flexibility of the sleeve and the riser pipe itself beyond either end of the sleeve resulting in a rather stiff system in bending.
[0013] Another type has the riser centralized in a larger diameter pipe called a stem. The stem is suspended directly from the buoyancy module at the top of the riser. The stem performs the same function as the sleeve in the aforementioned example but in this version the riser is not connected to the stem but only centralized within it using a ball type centralizer that allows the riser to pivot and curve relative to the stem.
SUMMARY OF THE INVENTION
[0014] The invention addresses the needs in the known art. What is provided is a tapered riser joint that is connected to a larger diameter outer sleeve through a connection that allows the tapered section and outer sleeve to function as one unit. Working as one unit, fewer and smaller parts are required than when similar pieces are configured to function separately. In the combined design, the outer sleeve provides the required sliding interface between the riser and the guide at the keel of the hull while also providing some of the bending compliance needed to transition from the riser supported in the hull to the riser unsupported below the hull. Also in this design, the tapered section provides the remaining bending compliance needed for the transition.
[0015] The connection between the tapered and sleeve sections is a forged, machined ring plate welded to the bottom end of the sleeve which provides a base for either bolted or threaded type attachment points for the tapered riser joint below the ring plate and the internal riser joint that continues to the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a further understanding of the nature and objects of the present invention reference should be made to the following description, taken in conjunction with the accompanying drawings in which like parts are given like reference numerals, and wherein:
[0017] FIG. 1 is an elevation view that illustrates the preferred embodiment of the installed invention.
[0018] FIG. 2 is a detailed view of the circled area indicated by the number 2 in FIG. 1 .
[0019] FIG. 3 is an alternate embodiment of the circled area indicated by the number 2 in FIG. 1 .
[0020] FIG. 4 is an elevation view of an alternate embodiment of the invention.
[0021] FIG. 5 is a detailed view of the circle area indicated by the number 5 in FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] Referring to the drawings, it is seen in FIG. 1 that the invention is generally indicated by the numeral 10 . The riser keel joint assembly 10 is generally comprised of a single tapered riser joint 12 , a sleeve 14 , and an internal riser joint 16 installed on a floating offshore structure 11 .
[0023] Tapered riser joint 12 is connected to the sleeve 14 and internal riser joint 16 at a connecting flange 18 .
[0024] The internal riser joint 16 may be formed from one or more riser joints, depending upon the length of riser required relative to the sleeve 14 . When a second internal riser joint 15 is required, a mechanical joint 17 is used to connect the joints 15 and 16 . The sleeve 14 may also be extended through the use of a mechanical connector 19 when its total length is over the drilling rig length handling limitations during riser installation. The internal riser joint 16 / 15 is provided with a centralizer 20 near the upper end of sleeve 14 . Mechanical joints and centralizers are generally known in the industry. The sleeve 14 is laterally supported by guides 13 at two elevations in the keel region of the offshore structure 11 so the guides 13 develop a moment resisting couple acting on the sleeve 14 .
[0025] FIG. 2 illustrates the details of the preferred connecting flange 18 . A threaded flange 22 is rigidly attached to sleeve 14 by any suitable means such as welding. Flange 22 has a central, threaded bore that is sized to receive the threaded end 24 of internal riser joint 16 . Flange 22 is also provided with threaded bores 26 which receive pre-tension bolts 28 when attaching tapered riser joint 12 to the flange 22 . Nuts 30 on the pre-tension bolts 28 secure the tapered riser joint 12 in place. Tapered riser joint 12 is provided with a suitable flange 23 such as an API 6A flange at the upper end to accomplish the connection. A gasket 32 is inserted between the flanges to maintain the internal pressure and seal at the connection of the two risers. The gasket 32 is preferably a pressure energized ring gasket. The tapered profile of threaded flange 22 provides the welding access to the outer sleeve 14 . The overall shop assembly length, including the tapered riser joint 12 and sleeve 14 is determined by the rig installation capacity. The internal riser joint 16 is readily installed in the sleeve 14 at the offshore location of the structure 11 due to the threaded connection on flange 22 . The API 6A flange 23 and tapered riser 12 may be machined from one forged piece. However, welding a standard API 6A flange to the tapered riser joint 12 is more economically efficient. The tapered riser joint 12 and the lower part of the sleeve 14 may be pre-assembled to the flange 22 in the shop while the rest of the parts are installed at the offshore site using a drilling rig.
[0026] FIG. 3 illustrates an alternate embodiment of the connecting flange 18 arrangement. In this embodiment, the threaded end 24 of the internal riser joint 16 is replaced with an API 6A flange 34 which has the same dimension and profile as the flange 23 on the tapered riser joint 12 . This allows easy matching and bolting of both flanges 23 and 34 to threaded flange 22 . Each flange 23 , 34 is provided with a gasket 32 as described above. Threaded flange 22 provides the same function as an attachment point for the tapered riser joint 12 , internal riser joint 16 , and sleeve 14 . In this embodiment the internal riser joint 16 is pre-assembled in the shop rather than installed offshore. This embodiment has the same function and mechanical behaviors as the embodiment of FIG. 2 .
[0027] FIG. 4 and 5 illustrate an alternate embodiment of the invention that uses a compliant ball mechanism 36 between the riser joints and the sleeve 14 . A thick wall dual tapered riser section 38 with a keel ball 40 attached is received in ball socket 42 . The compliant ball mechanism is preferably moved up from the lower end of the sleeve 14 . The ball socket 42 is formed by clamping together the two halves using pre-tension bolts and then rigidly attaching the mechanism to the sleeve 14 by any suitable method such as welding. The smooth contact between keel ball 40 and ball socket 42 allows for the desired relative rotation between the riser 38 and the sleeve 14 . The internal riser and sleeve below the compliant ball mechanism are pre-assembled in the shop before transfer to the offshore installation. This embodiment provides more flexibility than the embodiment of FIG. 1 and 2 .
[0028] The bottom of the sleeve 14 is preferably positioned approximately twenty feet below the bottom of the keel of the offshore structure 11 . As seen from the description and drawings, the connection between the sleeve and riser causes them to act as one unit moving up and down in the keel of the offshore structure as the riser moves up and down relative to the structure in response to the environmental motions of the structure. The invention provides a flexible mechanical assembly with adequate strength and friendly fatigue resistant details for high stroke demand top-tensioned riser arrangements.
[0029] The invention provides numerous advantages over the known art.
[0030] The arrangement of the invention provides a flexible mechanical assembly with adequate strength and friendly fatigue resistant details for a high stroke demand top-tensioned riser arrangement.
[0031] A problem solved by the invention is to provide a compliant assembly to accommodate the relative pitch and stroke between the riser system and hull structure. This is accomplished by adding a tapered riser joint to the lower part of a long piece of outer sleeve bushing in the hull keel structure. It should be understood that the position of the bottom end sleeve below the hull keel structure is important for this invention and this is controlled by the length of the sleeve that is used.
[0032] The result is an extension of the fatigue life of the system by providing sufficient flexibility in the keel joint assembly in a manner that is lower in cost than the prior art.
[0033] Another problem solved by the invention is to provide three types of mechanical interfaces as an attachment point for the lower tapered riser joint and upper riser joint inside the sleeve to the stem sleeve. The interface can be either rigid moment connection or ball type pin connection. This configuration has a wide application from relatively shallow water to ultra-deep water.
[0034] The invention provides a significant reduction in the time, cost, and risk offshore to install the can and keel joint system. By adding a sliding keel sleeve to the riser system at the keel region instead of the conventional way of adding a long stem hanging from the buoyancy can, the suspended load on the buoyancy can is lessened and the can does not have to be attached to the sleeve in the field.
[0035] Another advantage is that the sliding keel sleeve can be run using a drilling rig in the normal course of running the risers. The overall length of the keel joint assembly of the invention is approximately ninety feet. However, the pre-assembled length of each joint is not more than sixty feet, which is less than the general installation joint length limits of the drilling rig. A mechanical connector is used to make up the two lengths of sleeve that constitute the full joint. Therefore, no special installation equipment is required to install the keel joint assembly of the invention.
[0036] Another advantage is that a large stroke is allowed in this invention. The total stroke can reach to a large magnitude up to sixty feet. This amount of stroke covers a wide stroke range of the Spar top-tensioned riser from 2 , 000 to 10 , 000 foot water depth.
[0037] Another advantage is that the preferred embodiment of the invention has only a single tapered riser joint. Compared to the conventional design of a dual tapered riser joint, it cuts the length and volume of the forged, machined, tapered pieces by half. Significant material and machining work is reduced.
[0038] Another advantage is that the invention maximizes the utilization of the standard API 6A connectors and profiles. This off-the-shelf flange technology minimizes the application risk while simplifying the design and testing procedures required.
[0039] As in all keel joints, the maximum bending moment occurs when the offshore structure is in its maximum laterally offset position because this is also the time when the points of load transfer between the riser and the keel joint are at the maximum distance below the keel guide, thus creating the largest distance between the lateral force and the guides resisting the lateral force (the largest bending moment in the keel joint). In this invention, when the riser is in this maximum downward position, the keel joint sleeve is at its most flexible and thus best able to draw bending moment away from the riser pipe itself. When the keel is minimally offset, the keel joint sleeve is at its stiffest position but the bending moments on the riser are the smallest so this stiffness is acceptable.
[0040] The invention introduces:
[0041] elimination of the need for a stem section from the keel to the buoyancy can. Normally, this means two hundred fifty to three hundred feet of stem is eliminated on each riser.
[0042] elimination of the weight of these long stem sections on the buoyancy cans.
[0043] two levels of guides to provide moment resistance for the sleeve section.
[0044] joint construction almost entirely from off-the-shelf items.
[0045] a simple bolted connection using standard flanges that can be readily made up in the field.
[0046] elimination of the special tapered, heavy wall section of riser above the riser-sleeve connection (the section of riser inside the sleeve).
[0047] Because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. | A riser joint keel assembly. A tapered riser joint is connected to a larger diameter outer sleeve through a connection that allows the tapered section and outer sleeve to function as one unit. In the combined design, the outer sleeve provides the required sliding interface between the riser and the guide at the keel of the hull while also providing some of the bending compliance needed to transition from the riser supported in the hull to the riser unsupported below the hull. The tapered section also provides the remaining bending compliance needed for the transition. The connection between the tapered and sleeve sections is a forged, machined ring plate welded to the bottom end of the sleeve, which provides a base for either bolted or threaded type attachment points for the tapered riser joint below the ring plate and the internal riser joint that continues to the surface. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods for thermostamping thermoplastic composites; and, more particularly relates to a method for thermostamping composites involving radio frequency heating of the composite.
2. Description of Related Art
Radio frequency heating of thermoplastic composites in molding processes is known, see for example Thorsrud, U.S. Pat. No. 4,840,758. The molding processes involving radio frequency heating have, however, generally been relatively slow processes.
Convection heating of thermoplastic composites is also known, however, convection heating of composites made from non-woven, compressed, randomly dispersed fiber webs results in melting of the resin at the surface of the composite which allows lofting of the fibers at the composite surface resulting in insulation of the center of the composite thereby resisting heat transfer to the composite's center resulting in uneven heating across the thickness of the composite.
Accordingly, one object of the present invention is to provide a thermostamping method which provides quick heating of the composite with uniform heat distribution therethrough.
SUMMARY OF THE INVENTION
The present invention involves a method of thermostamping thermoplastic composites and comprises (a) convection heating of the composite to the glass transition temperature of the thermoplastic; (b) radio frequency heating of the composite from the glass transition temperature of the thermoplastic to the melt stamping temperature, for example the melt temperature of the thermoplastic; and (c) stamping of the composite into the desired shape.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, a method is provided for thermostamping thermoplastic composites involving (a) convection heating of the composite to the glass transition temperature of the thermoplastic; (b) radio frequency heating of the composite from the glass transition temperature of the thermoplastic to the melt stamping temperature, for example the melt temperature of the thermoplastic; and (c) stamping of the composite into the desired shape.
The thermoplastic composites comprise respective amounts of thermoplastic resin; reinforcing fibers and a radio frequency sensitizing agent. The composites are preferably compression consolidated from randomly oriented fibers dispersed in a polymeric matrix. Suitable methods for making the composites are set forth in Gatward et al U.S. Pat. No. 3,716,449 which is incorporated herein by reference. The composites can be made by first using a paper making process to make a liquid dispersion of reinforcing fiber and plastic powder to form a web of randomly oriented fibers dispersed in a plastic powder matrix followed by heat and pressure consolidation of the web to make a composite having compressed fibers locked therein by the thermoplastic resin. The compression consolidation results in the randomly oriented fibers exerting forces within the composite such that heating of the composite during thermostamping results in lofting of the fibers and expansion in the total thickness of the composite.
Suitable thermoplastics include, for example, aromatic polycarbonates such as bisphenol-A polycarbonates; polyamides such as polyamides derived from hexamethylene diamine and isophthalic acid; polyesters such as polyethylene terephthalate and polybutylene terephthalate; copolyetheresters; and polyolefin blends such as polyethylene or polypropylene blended with an acrylic resin or a polyamide. Other thermoplastic polymers and blends of thermoplastic polymers may also be useful. The preferred thermoplastic is polybutylene terephthalate.
The reinforcing fibers preferably are glass fibers having diameters from 5 to 30 microns and lengths of from 0.125 inches to 0.75 inches. The fibers may be individual fibers or fiber bundles. In addition to glass, the aromatic polyamides or other fiber forming inorganic materials or mixtures may be employed. The reinforcing fibers are preferably present at a level of from between 10 and 60 precent by weight of the composite, more preferably from 15 and 40 percent by weight thereof and more preferably about 25-30 percent by weight of the composite.
Suitable radio frequency energy sensitizing agents can be any of known sensitizers such as zinc oxide, bentonite clay, and N-ethyl toluene solfonamide. Suitable radio frequency energy sensitizing agents also include sensitizers for polycarbonate derived from disphenol A and phosgene, those sensitizers include polyamides such as nylon 6,6 and polyacrylics at levels of from 2 to 20 percent by weight based on the total weight of the composite. In general the sensitizer is present at from about 1 weight percent to about 20 weight percent based on the total weight of the composite, and preferably from 4 weight percent to 12 weight percent thereof.
The method of the present invention involves the steps of: (a) convection heating of the composite to the glass transition temperature of the thermoplastic; (b) radio frequency heating of the composite from the glass transition temperature of the thermoplastic to the stamping temperature, for example melt temperature of the thermoplastic; and (c) stamping of the composite into the desired shape.
The convection heating step can be accomplished by a conventional convection heating oven external from the thermostamping compression molding apparatus. The convection oven heats the composite to a temperature near the glass transition temperature of the thermoplastic matrix resin. The convection oven allows for the heating of the composite to the glass transition temperature of the resin fairly rapidly. By employing the convection heating step the composite is heated to the glass transition temperature of the resin much faster than radio frequency alone because radio frequency heating is less effective at temperatures below the glass transition temperature of the resin. The effectiveness of radio frequency heating tends to be a function of the mobility of the thermoplastic molecules and this is less effective at lower resin temperatures than at higher resin temperatures. In contrast, convection heating of non-woven radom fiber compression consolidated composites tends to be more effective at composite temperatures below the glass transition temperature of the resin because once the composite surface is sufficiently hot to allow the compressed fibers to loft, then the lofted fibers at the surface insulate the composite center and resist heating thereof resulting in a temperature gradient across the thickness of the composite which results in poor quality articles upon thermostamping of the composite. The convection heating step involves heating the composite from ambient temperature, for example room temperature (25° C.), to about the glass transition temperature of the thermoplastic material, preferably within 25° C. of the glass transition temperature (i.e. between 25° C. above and below the glass transition temperature of the resin), and more preferably within 10° C. of the glass transition temperature.
Once the composite is heated to about its glass transition temperature then the composite is heated further by radio frequency engergy to the thermostamping temperature of the composite. The thermostamping temperature of the composite is at or above the melt temperature of the resin when crystalline thermoplastics are the matrix resin and at or above the glass transition temperature plus about 150° C. when the matrix resin is an amorphous resin having no distinct melting point. For crystalline resins the thermostamping temperature is preferably between the melt temperature and 100° C. above the melt temperature, more preferably from 20° C. to 70° C. above the melt temperature, and most preferably about 50° C. above the melt temperature. For amorphous resins having no distinct melting point the thermostamping temperature is preferably between 150° C. above the glass transition temperature of the resin and 300° C. above the glass transition temperature of the resin, more preferably between 200° C. and 275° C. above the glass transition temperature, and most preferably about 250° C. above the glass transition temperature.
Once the composite is heated to its final thermostamping temperature then it is thermostamped into its desired shape article by placing the heated composite between two mold halves having temperatures of about 100° F. to 250° F. and is compressed under pressures of from 2,000 to 6,000 pounds per square inch. The final shaped parts of articles are useful as structural components in automotive applications, etc.
The radio frequency step can be accomplished by a radio frequency energy heating source external from the mold or may be heated by employing a pair of shuttling mold bases each having an RF electrode therein and placing the composite between a portable RF electrode and one of the mold bases and heating the composite, then removing the portable RF electrode, shuttling the base with the heated composite to a position below the thermostamping top mold halve, and thermostamping the composite while heating the next composite between the other mold half and the portable RF electrode. This shuttling process can be repeated in a step wise fashion. | A method for thermostamping thermoplastic composites involves the steps of (a) convection heating of the composite to the glass transition temperature of the thermoplastic; (b) radio frequency heating of the composite from the glass transition temperature of the thermoplastic to the desired stamping temperature; and (c) stamping of the composite into the desired shaped article. The method provides for improved temperature uniformity throughout the composite prior to stamping thereof resulting in more uniform parts. | 1 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates in general to a downhole apparatus and method for generating electricity and, in particular to, a downhole electrical generator that uses lift fluid pressure to produce electricity which is used to operate other downhole devices.
BACKGROUND OF THE INVENTION
Without limiting the scope of the invention, its background is described in connection with the operation of downhole electrical devices, as an example. The control and operation of oil and gas production wells constitute an important and ongoing concern of the petroleum industry. As an example, well control has become particularly important and more complex in view of the industry wide development of multilateral wells. Generally speaking, multilateral wells have multiple branches each having discrete production zones which produce fluid into common or independent production tubing. In either case, there is a need for controlling zone production, isolating specific zones and otherwise monitoring each zone in a particular well. As a result, the methods and devices used for controlling wells are growing more complex. In fact, downhole control systems which include downhole computerized modules employing downhole computers for commanding downhole tools such as packers, sliding sleeves and valves are becoming more common.
For example, using downhole sensors, a downhole computer controlled system may monitor actual downhole parameters such as pressure, temperature and flow to automatically execute control instructions based upon the monitored downhole parameters. As should apparent, operating such a well control systems will require electrical power. It has been found, however, that presently known methods of supplying or generating electricity downhole suffer from a variety of problems and deficiencies.
In one method, electricity may be supplied downhole by lowering a tool on a wireline and conducting electricity through one or more conductors in the wireline from the surface to the tool. Similarly, hardwires may be attached on the exterior of the tubing running from the surface to the desired downhole location. These techniques, however, are not desirable due to their cost and complexity. In addition, in deep wells, there can be significant energy loss caused by the resistance or impedance in the wires.
Downhole electrical circuits utilizing batteries housed within a downhole assembly have also been attempted. These batteries, however, can only provide moderate amounts of electrical energy at the elevated temperatures encountered downhole. In addition, batteries have relatively short lives requiring frequent replacement and/or recharging.
Other attempts have been made to provide a downhole mechanism which continuously generates and supplies electricity. For example, systems using radioisotopes, fuel cells and piezoelectric techniques have been attempted. These systems, however, have raised safety and environmental concerns, are expensive and complex and/or do not generate suitable amounts of electricity.
A more promising approach to supplying electricity downhole appears to be the use of downhole electrical generators. Previous attempts to operate downhole generators, however, have met with limited success. Specifically, many downhole generators are installed within the tubing string which prevents the passage of other tools or equipment therethrough. Other downhole generators have been proposed that are installed in side pockets thus allowing passage of equipment through the tubing.
All of these downhole generators, however, suffer from a serious drive problem. Specifically, the turbines of these downhole generators are rotated by the upward flow of production fluids. Not only does this create an undesirable pressure drop in the production fluids, but use of production fluids to drive turbines significantly limits the life expectancy of these downhole generators. Specifically, the mechanical and chemical qualities of production fluids tend to erode and corrode the turbine as well as other components of these downhole generators. In addition, tars and suspended solids in the production fluid tend to clog flow passageways within these downhole generators and prevent proper rotation of the rotors. Also, the amount of the electrical output of these production fluid driven downhole generators is controlled by the flow rate of production fluid through the tubing which is dependent, in part, upon the pressure in the formation which decreases over time.
Therefore, a need has arisen for a downhole generator that is not driven by the flow of production fluids through the tubing. A need has also arisen for such a downhole generator that does not cause a pressure drop within the production fluids. Further, a need has arisen for such a downhole generator wherein the electrical output is not dependent upon the pressure in the formation from which the production fluids are produced.
SUMMARY OF THE INVENTION
The present invention disclosed herein comprises a lift fluid driven downhole electrical generator that does not use the flow of formation fluids to drive a turbine. As such, the lift fluid driven downhole electrical generator of the present invention does not choke the flow of formation fluids up through the tubing. In addition, the electrical output of the lift fluid driven downhole electrical generator of the present invention is not dependent upon the flow rate of formation fluids or the pressure in the formation from which the formation fluids are produced.
Broadly characterized, the lift fluid driven downhole electrical generator, once positioned downhole in a tubing string, converts the lift fluid pressure into electricity. For example, the lift fluid may be used to create rotary motion by impinging the lift fluid against a rotor. The rotary motion may then be converted to electricity by rotating a first portion of an electromagnetic assembly relative to a second portion of the electromagnetic assembly.
The lift fluid driven downhole electrical generator comprises a housing having one or more lift fluid ports in a sidewall portion thereof for receiving the lift fluid from the annulus surrounding the tubing string. A flow control device that is slidably disposed within the housing is used to selectively allow and prevent the flow of lift fluid through the lift fluid port. The openness of the lift fluid port may be controlled by the operation of an actuator that is operably coupled to the flow control device. The actuator may infinitely vary the openness of the lift fluid port between the fully open and fully closed positions in response to a signal from the surface received by a downhole telemetry system, a signal from a downhole sensor or a timer. Alternatively, a controller may be used to monitor the electrical output of the downhole generator and then send a signal to adjust the position of the flow control device relative to the lift fluid port to vary the electrical output of the downhole generator if desired.
When the lift fluid ports are open, a rotor, rotatably disposed within the housing, converts the lift fluid pressure to rotary motion as the lift fluid impinges the rotor. The rotation of the rotor is imparted on the first portion of the electromagnetic assembly which is rotatable relative to the second portion of the electromagnetic assembly, which is stationary with the housing. This relative rotation within the electromagnetic assembly converts the rotary motion to electricity. The first portion of the electromagnetic assembly includes a plurality of electrical windings wrapped around a core. One end of the electrical windings is electrically coupling to a first portion of a commutator and the other end of the electrical windings is electrically coupling to a second portion of the commutator. The second portion of the electromagnetic assembly includes magnets and at least two contact members that are stationary with the housing of the downhole electrical generator. In operation, when the first portion of the electromagnetic assembly is rotated relative to the second portion of the electromagnetic assembly, a first contact member sequentially engages the first portion of the commutator then the second portion of the commutator while a second contact member simultaneously sequentially engages the second portion of the commutator then the first portion of the commutator. As such, electricity is generated by the lift fluid driven downhole electrical generator of the present invention.
In addition, the present invention may be used to control the electrical output of a lift fluid driven downhole electrical generator. This is achieved by positioning the downhole electrical generator within a tubing string, injecting a lift fluid down an annulus surrounding the tubing string, providing a fluid communication path through the downhole electrical generator by varying the position of a flow control device relative to a lift fluid port, communicating lift fluid through the lift fluid port, rotating a rotor and an electromagnetic assembly such that electricity is generated in response to the flow of lift fluid through the fluid communication path, sensing the generated electricity to determine the electrical output of the downhole electrical generator and adjusting the flowrate of lift fluid through the fluid communication path by selectively varying the position of the flow control device relative to the lift fluid port, thereby controlling the electrical output of the downhole generator.
More specifically, the step of sensing the generated electricity to determine the electrical output of the downhole electrical generator may include receiving a signal indicative of the magnitude of the electricity being generated with a controller, processing the signal in the controller and generating a control signal with the controller to vary the position of the flow control device relative to the lift fluid port.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, including its features and advantages, reference is now made to the detailed description of the invention, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic illustration of an offshore oil and gas production platform operating a lift fluid driven downhole electrical generator of the present invention;
FIG. 2 is a partial cross sectional view of a lift fluid driven downhole electrical generator of the present invention in its closed position;
FIG. 3 is a partial cross sectional view of a lift fluid driven downhole electrical generator of the present invention in its fully open position; and
FIG. 4 is a partial cross sectional view of a lift fluid driven downhole electrical generator of the present invention in a partially open position.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
Referring to FIG. 1, an offshore oil and gas production platform operating a lift fluid driven downhole electric generator is schematically illustrated and generally designated 10 . A semi-submersible platform 12 is centered over a submerged oil and gas formation 14 located below sea floor 16 . Wellhead 18 is located on deck 20 of platform 12 . Well 22 extends through the sea 24 and penetrates the various earth strata including formation 14 to form wellbore 26 . Disposed within wellbore 26 is casing 28 . Disposed within casing 28 and extending from wellhead 18 is production tubing 30 . A pair of seal assemblies 32 , 34 provide a seal between tubing 30 and casing 28 to prevent the flow of production fluids therebetween. During production, formation fluids enter wellbore 26 through perforations 36 in casing 28 and travel into tubing 30 to wellhead 18 .
Coupled within tubing 30 is a lift fluid driven downhole electrical generator 38 . Downhole electrical generator 38 is driven by lift fluid communicated thereto from surface installation 40 , through fluid conduit 42 and the annulus between casing 28 and tubing 30 as will be explained in greater detail below.
In addition, the lift fluid may be used to enhance the recovery of hydrocarbons from formation 14 by decreasing the hydrostatic head of the column of formation fluid in wellbore 26 . Decreasing the hydrostatic head enhances recovery by reducing the amount of pressure required to lift the formation fluids to the surface. Decreasing the density of the column of fluid extending from formation 14 to the surface reduces the hydrostatic head of this fluid column. As such, mixing a lower density fluid into the formation fluids reduces the overall density of the fluid column and consequently decreases the hydrostatic head. Accordingly, low density fluids, including liquids such as a hydraulic fluid or gases may be used.
Even though FIG. 1 depicts a vertical well, it should be noted by one skilled in the art that the present invention is equally well-suited for slanted wells, deviated wells or horizontal wells. Also, even though FIG. 1 depicts an offshore operation, it should be noted by one skilled in the art that the present invention is equally well-suited for use in onshore operations.
Referring now to FIG. 2, therein is depicted a lift fluid driven downhole electrical generator of the present invention that is generally designated 50 . Generator 50 has an outer housing 52 that is a substantially cylindrical tubular member that is threadedly and sealingly coupled to tubing string 30 , as seen in FIG. 1, at its upper and lower ends. It should be apparent to those skilled in the art that the use of directional terms such as top, bottom, above, below, upper, lower, upward, downward, etc. are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. As such, it is to be understood that the downhole components described herein may be operated in vertical, horizontal, inverted or inclined orientations without deviating from the principles of the present invention.
Housing 52 has a primary flow passageway 54 extending longitudinally therethrough. Housing 52 also has one or more lift fluid ports 56 radially extending through the side wall thereof. In the illustrated embodiment, multiple ports 56 are disposed around the same circumference of housing 52 , however, other ports could be disposed either above or below ports 56 along the length of housing 52 if desired.
Housing 52 can be made of any suitable material, such as metal, plastic or ceramic capable of withstanding the pressures, temperatures and substances downhole. The material for housing 52 may be machined or formed to have a desired shape and size including a radially expanded inner diameter region 58 and interior cavities 60 , 62 and 64 for purposes to be described below.
Disposed within radially expended inner diameter region 58 of housing 52 is an inner subassembly 70 that is rotatably and axially moveable relative to housing 52 . Inner subassembly 70 has a primary flow passageway extending longitudinally therethrough that preferable has the same inner diameter as primary flow passageway 54 of housing 52 . Inner subassembly 70 includes a flow control device 72 for selectively allowing fluid flow or preventing fluid flow through ports 56 . Flow control device 72 is disposed in housing 52 such that flow control device 72 is moveable between a closed position, fully obstructing ports 56 , as best seen in FIG. 2, a fully open position, completely unobstructing ports 56 , as best seen in FIG. 3, and a partially open position partially obstructing ports 56 , as best seen in FIG. 4 . As will be explained below, the position of flow control device 72 is infinitely variable relative to ports 56 such that the electrical output of generator 50 may be controlled.
In the illustrated embodiment, flow control device 72 is an annular body made of a suitable material providing for a bearing seal between the exterior surface of flow control device 72 and the interior surface of housing 52 , such as a metal-to-metal seal. As illustrated, the height of flow control device 72 is sufficient to overlie ports 56 when ports 56 are to be closed.
Alternatively, instead of using an integral flow control device such as flow control device 72 , the flowrate of lift fluid into lift fluid ports 56 may be controlled by lift fluid valves installed within lift fluid ports 72 or in a side pocket mandrel adjacent thereto. The openness of the lift fluid valves may be controlled using known techniques, but are preferably electrically controlled.
Inner subassembly 70 includes a rotor 74 that provides an interface with the lift fluid whereby rotor 74 is driven by the lift fluid entering generator 50 through ports 56 . Rotor 74 is used to convert fluid flow to mechanical power. Specifically, rotor 74 is connected to flow control device 72 such that as flow control device 72 opens ports 56 , flow of a lift fluid into ports 56 impinges rotor 74 to rotate rotor 74 . In one embodiment, the connection between rotor 74 and flow control device 72 is such that both move linearly and rotate together. In another embodiment, joint linear movement occurs but rotor 74 can rotate relative to flow control device 72 using, for example, a sealed bearing coupling.
In the illustrated embodiment, rotor 74 has two degrees of motion. Rotor 74 can rotate about its longitudinal axis and rotor 74 can move linearly or axially within housing 52 . In the illustrated embodiment, this linear movement occurs simultaneously with and in conjunction with the longitudinal movement of flow control device 72 . As illustrated, flow control device 72 and rotor 74 are linearly disposed and adjoin each other within radially expended inner diameter region 58 of housing 52 .
Rotor 74 of the illustrated embodiment has a cylindrical squirrel cage configuration comprising a plurality of angled vanes 76 that are circumferentially separated such that the spaces between vanes 76 permit radial fluid flow between the outside and the inside of rotor 74 and such that an axial channel is defined through rotor 74 to permit axial flow between adjoined vanes 76 as well as through generator 50 . As such, rotor 74 is driven by lift fluid flowing into generator 50 through open ports 56 . The resulting mechanical power of rotor 74 is used to generate electricity as explained below.
As mentioned above, rotor 74 and flow control device 72 are connected such that they can be moved linearly within housing 52 . In the illustrated embodiment, this movement is caused by an actuator 78 . Actuator 78 moves flow control device 72 and rotor 74 linearly to variably adjust the openness of ports 56 and to provide infinite flow control throughout the continuum between fully closed and fully opened.
Actuator 78 is mounted within interior cavity 64 of housing 52 and is coupled to inner subassembly 70 linking actuator 78 with rotor 74 . Operation of actuator 78 moves inner subassembly 70 , including rotor 74 and flow control device 72 axially within housing 52 to displace flow control device 72 relative to ports 56 .
In the illustrated embodiment, actuator 78 includes a motor 80 . Motor 80 includes a rotating element 82 having a threaded inner surface which engages a threaded outer surface of a ring 84 . Ring 84 is axially fixed with respect to linear movement relative to mandrel 86 of inner subassembly 70 by retaining rings 88 , 89 . Ring 84 is rotatably coupled on mandrel 86 such that mandrel 86 can rotate inside ring 84 . To obtain axial movement, ring 84 is maintained rotationally stationary relative to rotating element 82 of motor 80 so that operation of rotating element 82 drives ring 84 and mandrel 86 up or down as desired.
Alternatively, linear movement of inner subassembly 70 inside housing 52 could be achieved manually using a shifting tool. For example, such a shifting tool can be connected to either end of inner subassembly 70 and operated to mechanically pull or push inner subassembly 70 up or down.
In the illustrated embedment, when actuator 78 has moved flow control device 72 to a partially or fully open position, lift fluid induced rotation of rotor 74 may now occur. Such rotation, in turn, causes operation of an electromagnetic assembly 90 . Electromagnetic assembly 90 provides an electrical interface which converts mechanical power to electricity.
Electromagnetic assembly 90 includes a mandrel 92 that provides support for a plurality of electrical windings 94 , a plurality of pole pieces 96 and a commutator 98 , which are also considered to be part of electromagnetic assembly 90 . Mandrel 92 is connected to rotor 74 . As illustrated, mandrel 92 and rotor 74 are integral and unitary, being constructed with the same tubing piece. Mandrel 92 is also coupled to mandrel 86 .
The plurality of electrical windings 94 are wound on mandrel 92 . The plurality of pole pieces 96 are disposed radially outwardly of windings 94 so that pole pieces 96 overlie windings 94 . Commutator 98 serves as a brush ring and is connected to electrical windings 94 in a known manner so that one end of windings 94 is connected to one or more electrically parallel segments of commutator 98 and the other end of windings 94 is connected to one or more different electrically parallel segments of commutator 98 . Commutator 98 is made of suitable electrically conductive material.
Electromagnetic assembly 90 also includes a plurality of magnets 100 mounted within interior cavity 60 of housing 52 such that magnets 100 interact with electromagnetic fields generated by electrical windings 94 . The position of cavity 60 , and thus of magnets 100 within cavity 60 , is such that magnets 100 and pole pieces 96 are substantially aligned throughout the linear travel of inner subassembly 70 within housing 52 .
Electromagnetic assembly 90 also includes a plurality of contacts 102 mounted within interior cavity 62 of housing 52 . In the illustrated embodiment, contacts 102 are electrically conductive members such as brushes, that overlie and engage respective segments of commutator 98 . At least one contact 102 engages one section of commutator 98 connected to one end of windings 94 and at least one other contact 102 engages a different section of commutator 98 connected to the other end of windings 94 . Contacts 102 and commutator 98 are sized sufficiently so that electrical contact is made throughout the linear movement of inner subassembly 70 relative to housing 52 . Contacts 102 provide an interface to electrical wires such as wires 104 , 106 . Electricity generated by the present invention travels within wires 104 , 106 . This electricity can be used for powering devices for sensing parameters of the production fluid such as temperature, pressure, flow, density and the like using downhole sensors 108 , 110 . Likewise, the electricity may be used to power a downhole telemetry system 112 that may communicate with the surface via pressure pulses, acoustics, electromagnetic waves or other suitable wireless techniques. In addition, the electricity may be used to recharge batteries 114 .
To keep the lift fluid within the rotor section of inner subassembly 70 and to isolate the electrical components of electromagnetic assembly 90 from the lift fluid, the illustrated embodiment includes three seals. An O-ring seal 116 is mounted in a groove defined around the upper end of flow control device 72 . This places seal 116 above ports 56 . Seal 116 provides a fluid seal between flow control device 72 and the inner surface of housing 52 .
An O-ring seal 118 is mounted in a groove in mandrel 92 near the juncture of rotor 74 and mandrel 92 . Seal 118 provides a fluid seal between mandrel 92 and the inner surface of housing 52 between cavity 60 and ports 56 . This places seal 118 below ports 56 , and thus on the opposite side of ports 56 from seal 116 , thereby limiting the axial travel of the lift fluid therebetween.
O-ring seal 120 is mounted in a groove on mandrel 86 between commutator 98 and upper retaining ring 88 of actuator 78 . Seal 120 provides a fluid seal between mandrel 86 and the inner surface of housing 52 between cavities 62 , 64 .
An additional O-ring seal 122 is mounted in a groove on the lower end of inner subassembly 70 to prevent the entry of dirty formation fluids between inner subassembly 70 and housing 52 .
Generator 50 can be operated remotely using an onboard controller 124 housed within housing 52 . Controller 124 is of any suitable type to provide the necessary control and signal processing associated with the operation of generator 50 such as a microprocessor, however, other types of digital or analog controllers can be used.
In the illustrated embodiment, controller 124 receives electricity from wires 104 , 106 . Controller 124 can be used to distribute the electricity to the various electrical components associated with generator 50 . For example, controller 124 may be used to provide electricity as well as operation information to sensors 108 , 110 to obtain reading for pressure, temperature, density, flow rate or similar parameters associated with the production fluids. This information may then be returned to controller 124 and stored in a memory device associated with controller 124 . Thereafter, controller 124 may provide electricity and operating parameters to telemetry device 112 such that information received from sensors 108 , 110 may be wirelessly sent to the surface via pressure pulses, acoustics, electromagnetic waves or other suitable techniques known in the art. In addition, controller 124 may direct electricity to batteries 114 for storage and later use when, for example, generator 50 is not generating electricity.
Controller 124 may also be used to control the electrical output of generator 50 . Specifically, controller 124 may monitor a characteristic of the generated electricity, for example magnitude. This sensed electricity can be correlated to the flow rate of lift fluid through ports 56 . As such, the degree of openness of ports 56 may be adjusted to create the desired electrical output. For example, if it is desired to produce more electricity based upon the electricity characteristic monitored by controller 124 , then controller 124 can send a signal to actuator 78 to upwardly shift inner subassembly 70 and increase the degree of openness of ports 56 . Alternatively, if it is determined by controller 124 that less electricity should be produced, then controller 124 can send a signal to actuator 78 to downwardly shift inner subassembly 70 and decrease the degree of openness of ports 56 .
In operation, generator 50 generates electricity by at least partially unobstructing ports 56 by upwardly shifting flow control device 72 such that lift fluid in the annulus outside generator 50 flows through ports 56 into the flow channel inside rotor 74 , as best seen in FIG. 4 . This is performed in the illustrated embodiment of generator 50 by wirelessly sending a signal from the surface to telemetry system 112 to open ports 56 . This signal is sent to controller 124 where it is processed and sent to motor 80 . Motor 80 receives electricity from batteries 114 then operates rotating element 82 to axially upwardly shift ring 84 . This upwardly moves rotor 74 and flow control device 72 to open ports 56 . Alternatively, controller 124 can have an internal timer by which it is programmed to respond at preset time intervals to turn motor 80 on and off. Likewise, controller 124 may prompt motor 80 to operate based upon changes in the production fluid parameters sensed by sensors 108 , 110 .
The present invention uses feedback regarding the amount of electricity being generated by generator 50 in response to the lift fluid flow through rotor 74 with controller 124 . When the electrical signal indicates the desired electrical parameter is being achieved, motor 80 can be de-energized to stop the linear movement of inner subassembly 70 . Alternatively, motor 80 can be used to move inner subassembly 70 up and down to, respectively, increase or decrease the electrical output of generator 50 as desired.
When flow control device 72 has at least partially opened ports 56 , lift fluid drives rotor 74 which, in turn, rotates windings 94 and pole pieces 96 relative to magnets 100 and rotates commutator 98 relative to contacts 102 such that electricity is generated.
Another aspect of the operation of the present invention is moving flow control device 72 , together with rotor 74 , to selectively block ports 56 . As explained above, these components are moved together axially within housing 52 . The axial movement occurs in response to any suitable force which can be internally generated or externally applied. In the illustrated embodiment, motor 80 can be energized to drive inner subassembly 70 downwardly within housing 52 such that flow control device 72 closes ports 56 and prevents lift fluid from entering ports 56 .
It should be noted by those skilled in the art that even though the illustrated embodiments have depicted a rotatable electromagnetic assembly as the means for generating electricity, lift fluid could alternatively be used to provide the energy to generate electricity using other types of electricity generating devices including, but not limited to, expandable bladders, vibrating reeds, piezoelectric wafer stacks and the like, all of which are contemplated and considered within the scope of the present invention.
While this invention has been described with a reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | A lift fluid driven downhole electrical generator and method for generating and controlling the electrical output from the electrical generator is disclosed. The electrical generator comprises a housing having a lift fluid port in a sidewall portion thereof for allowing the flow of lift fluids therethrough. A rotor is rotatably disposed within the housing. The rotor converts lift fluid pressure to rotary motion when the lift fluid travels through the lift fluid port and impinges the rotor. The electrical generator also includes an electromagnetic assembly having a first portion that is rotatable with the rotor and a second portion that is stationary with the housing. The electromagnetic assembly converts the rotary motion to electricity as the first portion of an electromagnetic assembly rotates relative to the second portion of the electromagnetic assembly. | 4 |
[0001] This application claims the benefit of priority to U.S. Provisional Application having Ser. No. 61/012,851 filed on Dec. 11, 2007
FIELD OF THE INVENTION
[0002] The field of the invention is non-contact stimulation of excitable tissue. Particular applications include neural stimulation for the treatment of pain, migraine, angina symptoms, urinary incontinence, and activation of muscular contraction.
BACKGROUND
[0003] In order for pain to be perceived, a neural signal generally travels along an afferent nerve from the site of the pain, through the spinal cord and up to the brain. If the signal is inhibited, interrupted or “confused” along the way, the pain is relieved to some extent or replaced by paresthesia or tingling.
[0004] Neurons are specialized excitable cells that can transmit electrical signals via ionic transport across their membranes. The energy needed to initiate the excitement of the nervous tissue can be any of several different forms. Biologically, this ionic transport (depolarization) is generally initiated by chemical energy. This initiates depolarization at a synapse between neighboring neurons. Neurotransmitters released by one neuron can initiate the depolarization in the next neuron. In sensory afferent neurons the initiation energy can be one of many different forms of energy. It can be photons (as in the retina of the eye), mechanical air pressure (as in the ear), mechanical force (as in the skin), etc.
[0005] Within the first couple of mm of skin, there are several types of neurons specialized to be particularly susceptible to excitation by a particular mechanical stimulus. Below are some examples of the neurons, their typical skin depths and the particular sensitivity.
[0000]
TABLE 1
Meissner corpuscle
0.7 mm
Low frequency vibration
Merkel cell
0.9 mm
Pressure
Ruffini ending
1.5 mm
Lateral extension
Pacinian corpuscle
2.0 mm
High frequency vibration
[0006] The threshold energy needed to initiate depolarization is most efficient for the particular form associated in the preceding list. Each neuron can be stimulated by different energy expressions, but is most suited to a particular one.
[0007] In the case of neural stimulator devices the initiating energy is electrical. A voltage is applied between electrodes that are placed in the vicinity of nervous tissue that is intended to be stimulated. Current flows between the electrodes and through the nerve cells. When the electrical energy is above a certain threshold, the nerve cells in that region will be depolarized.
[0008] Depolarization is also achievable using ultrasound energy even if the threshold energy level for ultrasound is higher than for electrical stimulation. Similarly, axonal stimulation (along the length of the neuron rather than at the end suited for stimulation) is possible though not as efficient. In other words, a greater intensity will be needed to stimulate neurons in the middle.
Invasive Spinal Cord Stimulation
[0009] Many people who suffer from intractable chronic pain achieve a measure of relief from the use of implantable spinal cord stimulation systems. Generally, leads containing multiple electrodes are implanted on top of the dorsal surface of the spinal cord and connected to a pulse generator/processor located several inches away. Electrode stimulation configuration is chosen to optimize the effectiveness of the stimulating pulsations. More information about neuron-stimulation equipment and how it works can be found at the following:
http://www.medscape.com/viewarticle/554863 http://www.webmd.com/back-pain/guide/spinal-cord-stimulation http://www.medtronic.com/servlet/ContentServer?pagename=Medtronic/Website/Condition Article&ConditionName=Chronic+Back+and%2For+Leg+Pain&Article=bpain_art_nsproducts http://www.controlyourpain.com/index.cfm?langid=1 http://www.ans-medical.com/
Ultrasonic Stimulation of Muscle
[0015] For relief of muscle pain, unfocused ultrasonic therapy has been used to promote healing and relief of pain.
Ultrasonic Stimulation to Promote Bone Healing
[0016] Ultrasound has been used to promote bone healing. More information may be found at http://ortho.smith-nephew.com/us/node.asp?NodeId=2865. Excerpted:
[0017] “Treatment of fractures with the EXOGEN™ 4000+* Bone Healing System (low-intensity pulsed ultrasound) may speed healing, lower the need for further surgery, and get patients back to their normal activities faster . . . . The EXOGEN™ Bone Healing System utilizes low-intensity ultrasound to accelerate the healing of indicated fresh fractures up to 38% faster than normal healing. The Exogen™ Bone Healing System is also highly effective for use on non-healing fractures. The ultrasound device is a portable, lightweight unit that delivers the prescribed treatment in a convenient 20 minute daily regimen . . . treat themselves at home, thus freeing hospital resources from this task. The treatment is safe and has no contra-indications. It has been clinically proven in many thousands of patients worldwide.”
[0018] Exogen U.S. Pat. No. 6,432,070 Exogen, Inc. (Piscataway, N.J.), and all other extrinsic materials discussed herein, are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. Also, unless a contrary intent is apparent from the context, all ranges recited herein are inclusive of their endpoints, and open-ended ranges should be interpreted to include only commercially practical values.
Ultrasonic Neurolysis for Pain
[0019] Another way to address unrelenting, unmanageable pain (as in cancer patients) is to irreversibly destroy nerves associated with the pain. High Intensity Focused Ultrasound has been used to destroy nerve cells in the interest of relieving pain. See for example
http://depts.washington.edu/bioe/people/core/vaezy/vaezy.html or U.S. Pat. No. 7,305,264 or application 20060184069.
[0021] Other techniques have also been used to destroy nerve cells for this purpose. See for example Critical Evaluation of Chemical Neurolysis from Cancer Control: Journal of the Moffitt Cancer Center http://www.medscape.com/viewarticle/408975 — 3.
Ultrasonic Stimulation in Tactility Research
[0022] It has been shown that ultrasonic energy can stimulate nerves and cause tactile sensations. See for example http://www.biomedical-engineering-online.com/content/2/1/6 Can ultrasound be used to stimulate nerve tissue? Stephen J Norton, BioMedical Engineering OnLine 2003, 2:6doi:10.1186/1475-925X-2-6 and http://www.alab.t.u-tokyo.acjp/˜shino/research/pdf/icat01.pdf ICAT Dec. 5-7, 2001 Tokyo, JAPAN Focused Ultrasound for Tactile Feeling Display, Takayuki IWAMOTO, Taro MAEDA, and Hiroyuki SHINODA, The University of Tokyo.
[0023] Furthermore, it is well known that ultrasound can be transmitted into the human body, as illustrated for example in figures at the website http://www.sprawls.org/ppmi2/USPRO/.
[0024] Accordingly, ultrasound can be transmitted to non-superficial tissues to stimulate nerves.
TENS
[0025] Transcutaneous Electrical Nerve Stimulations (TENS) is a safe non-invasive drug-free method of pain management. Such units relieve pain by sending small electrical impulses through electrode pads placed on the skin to underlying nerve fibers http://www.vitalityweb.com/backstore/tenswork.htm
[0026] There are several proposed explanations for how TENS may work:
electrical stimulation of the nerve fibers block a pain signal from being carried to the brain activation of the release of natural chemicals called endorphins in the brain which act as analgesics stimulation of the nerves that perceive pain or light touch interference with nerve pathways effects on flow of vital energy (used to explain acupuncture) have also been offered to explain TENS TENS may affect the cardiovascular system, increasing heart rate and reducing blood pressure http://www.intelihealth.com/IH/ihtIH/WSIHW000/8513/34968/363973.html?d=dmtContent#background.
Non-Invasive Magnetic Stimulation
[0034] Transcranial magnetic stimulation (TMS) has been used to stimulate neurons, particularly in the brain. It uses very strong magnetic fields to create electrical fields that can stimulate neurons. The field strength decays rapidly with distance, so TMS is only used to create cortical stimulation—not deep brain stimulation. http://www.neuronetics.com/default.asp
Limitations of Present Technologies
[0035] When using electrodes to deliver stimuli to excitable tissue, electrical voltage gradient generally diminishes with distance from electrodes. It is very difficult to stimulate a target nerve without also stimulating many unintended nerves and muscles too. The nerves that are closest to the electrodes generally experience the highest voltage gradient, highest current flow, and are thus the most likely to be stimulated by the electrical pulse. The location of supra-threshold pulses can be adjusted by varying the location, quantity of and voltage of or current from the electrodes—but the supra-threshold region is always located between or very close to the electrodes.
[0036] Non-invasive electrical and unfocused ultrasonic neural stimulators do not do a good job of stimulating only the target nerves. The selection of nerves stimulated by the implantable system can be influenced by the placement of the electrodes and by selection of which electrode combination is actually utilized. Though this does a much better job of limiting the stimulating to the desired tissue, it has the considerable drawback of requiring invasive surgery.
[0037] Another drawback of implantable electrodes and leads is the eventual loss of effectiveness. This is often attributable to migration of electrodes with respect to the target nervous tissue. It is sometimes attributable to the necrosis of nervous tissue due to prolonged mechanical stress imposed by the electrodes and/or leads. Effectiveness can sometimes be re-established by changing the characteristics of the electrical pulses or by using different electrode combinations. In the extreme, the electrodes can be invasively re-positioned.
[0038] Loss of effectiveness can also be caused by an increase of excitability threshold of the target tissue. This degradation of tissue can be a response to the physical presence of the electrodes and leads and to the associated stresses.
[0039] Focused ultrasound has been used to destroy tissue and thus block pain. This has the drawback of not being reversible. Neural stimulation can be reversed, but neurolysis is essentially permanent. Targeting mistakes in are thus much more severe in focused ultrasound neurolysis than in neuro stimulation.
[0040] Thus, there is still a need for methods and devices that stimulate target nervous tissue without simultaneously inadvertently stimulating appreciable quantities of intervening and neighboring nerve and muscle tissue; and to do so without the need for invasive surgery. There is also a need to manipulate the position of the subcutaneous supra-threshold stimulus non-invasively, and to avoid degradation, necrosis or lysis of excitable target tissue.
[0041] It is an objective of various embodiments the current invention to deliver stimuli to target excitable tissue without direct contact, and without undue stimulation of other intervening or neighboring excitable tissue. It is a further objective of such embodiments to have the capability to adjust the location and timing and magnitude of the stimuli. It is a still further objective of such embodiments to have the capability of automatically adjusting the characteristics of the stimuli, including pulse strength, timing and location.
Additional Prior Art Information
[0042] Weblinks
http://www.medscape.com/viewarticle/554863 http://www.webmd.com/back-pain/guide/spinal-cord-stimulation http://www.medtronic.com/servlet/ContentServer?pagename=Medtronic/Website/ConditionArticle&ConditionName=Chronic+Back+and%2For+Leg+Pain&Article=bpain_art_nsproducts_m http://www.controlyourpain.com/index.cfm?langid=1 http://www.ans-medical.com/ http://ortho.smith-nephew.com/us/node.asp?NodeId=2865 http://depts.washington.edu/bioe/people/core/vaezy/vaezy.htmlCancer Control: Journal of the Moffitt Cancer Center http://www.vitalityweb.com/backstore/tenswork.htm http://www.intelihealth.com/IH/ihtIH/WSIHW000/8513/34968/363973.html?d=dmtContent#background http://www.harfangmicro.com/FAQ.html http://www.bioe.psu.edu/ultrasound/research/Saleh%20Smith%20IJH04.pdf http://www.olympusndt.com/data/File/intro_pa/Intro_PA_Chap1.en.pdf http://www.radiologyresearch.org/SPI01-MI4325-51.pdf http://www.victhom.com/en/realization-neurostep-8.htm http://www.neuronetics.com/
[0058] Journal Articles
http://www.medscape.com/viewarticle/408975 — 3 http://www.biomedical-engineering-online.com/content/2/1/6 Can ultrasound be used to stimulate nerve tissue? Stephen J Norton, BioMedical Engineering OnLine 2003, 2:6doi:10.1186/1475-925X-2-6 http://72.14.253.104/search?q=cache:-4JFY1BIEwoJ:www.alab.t.u-tokyo.ac.jp/˜shino/research/pdf/icat01.pdf+focused+ultrasound+for+tactile+feeling+display&hl=en&ct=clnk&cd=l&gl=us ICAT Dec. 5-7, 2001 Tokyo, JAPAN Focused Ultrasound for Tactile Feeling Display, Takayuki IWAMOTO, Taro MAEDA, and Hiroyuki SHINODA, The University of Tokyo A. B. Valbo: Properties of cutaneous mechano receptors in the human hand related to touch sensation, Human Neuro Biology, 3, pp. 3-14 Springer-Verlag, 1973
[0000]
US Patents
6,432,070
5,762,616
4,889,526
4,800,898
7,011,638
4,530,360
4,541,432
4,535,777
6,206,843
6,652,443
4,510,936
4,343,301
5,413,550
3,828,769
7,081,128
7,367,956
6,748,275
6,091,994
7,033,312
7,305,264
6,721,603
6,066,084
5,983,141
7,369,894
5,460,595
5,807,285
5,766,124
5,556,372
5,476,438
4,940,453
[0063] US Patent Applications 20060184069
SUMMARY OF THE INVENTION
[0064] The inventive subject matter provides apparatus, systems and methods in which a non-contact device stimulates excitable tissue beneath the skin without causing unduly uncomfortable stimulation of intervening tissue. The purpose of the stimulation can be for the relief of the perception of pain, for stimulating tissue to contribute to urinary continence, for behavior modification, or for stimulating other tissue.
BRIEF DESCRIPTION OF DRAWINGS
[0065] FIG. 1 a shows a representation of a front view of transducer head containing a number of individual transducers, each transducer depicted with a beam (depicted as translucent) emanating from it. The transducers are mounted along two crossing different radius curves. The beams emanating from the transducers parallel to the front plane can be seen to cross at a focal point beneath the transducer head.
[0066] FIG. 1 b shows a representation of a side view of the transducer head of FIG. 1 a containing a number of individual transducers, each transducer depicted with a translucent beam emanating from it. The beams emanating from the transducers parallel to the side plane can be seen to cross at a focal point beneath the transducer head; this point being deeper than the focal point evident in FIG. 1 a.
[0067] FIG. 1 c shows a representation of an isometric view of the transducer head of FIGS. 1 a and b containing a number of individual transducers, each transducer depicted with a translucent beam emanating from it. It can be seen that the half of the beams cross at a shallow focus; the other half intersect at a deeper focus.
[0068] FIG. 2 a shows a representation of a front view of transducer head containing nine individual transducers. The transducers are mounted so that the centerline of each one crosses directly through target focal points represented as small spheres. In the configuration depicted in this figure, three of the nine each transducer are depicted with a translucent beam emanating—each beam representing ultrasonic energy emanating from each transducer. These three beams can be seen to cross at the bottom target focal point.
[0069] FIG. 2 b shows a representation of the bottom view of the transducer head depicted in FIG. 2 a containing nine individual transducers.
[0070] FIG. 2 c shows a representation of an isometric view of the transducer head depicted in FIGS. 2 a and b.
[0071] FIG. 3 shows a representation of an isometric view of the transducer head depicted in FIG. 2 , in which a translucent beam is depicted as emanating from each. At each of the 5 spheres, three of the beams intersect.
[0072] FIG. 4 a shows a representation of the front view of the transducer head of FIGS. 2 and 3 with the housing removed to allow a more direct view of the transducers and the three beams that intersect at the top point.
[0073] FIG. 4 b shows a representation of the front view of the transducer head of FIG. 4 a with the three beams that intersect at one of the intermediate points depicted as translucent.
[0074] FIG. 4 c shows a representation of the front view of the transducer head of FIGS. 4 a and b with the three beams that intersect at the bottom point depicted as translucent.
[0075] FIG. 4 d shows a representation of the front view of the transducer head of FIGS. 4 a, b and c with translucent beams depicted as emanating from each of the nine transducers. Three beams intersect at each of the five points.
[0076] FIG. 5 a shows a representation of an isometric view of the transducer head of FIG. 4 a with the housing removed to allow a more direct view of the transducers and the three beams that intersect at the top point.
[0077] FIG. 5 b shows a representation of an isometric view of the transducer head of FIG. 4 b with the three beams that intersect at one of the intermediate points depicted as translucent.
[0078] FIG. 5 c shows a representation of an isometric view of the transducer head of FIG. 4 c with the three beams that intersect at the bottom point depicted as translucent.
[0079] FIG. 6 a shows an isometric view of a gimbal mounted focused transducer; one lever that controls rotations about an axis, a second lever that controls rotation about a second perpendicular axis; and a third that allows for helical rotation to adjust travel along the third axis that is orthogonal to that established by the plan of the prior two axes.
[0080] FIG. 6 b is an isometric view of the gimbal mounted focused transducer of FIG. 6 a, shown in partial section—affording a better view of a curved focused transducer within.
[0081] FIG. 7 shows a chart representing stimulation pulse train envelopes transmitted to the excitable tissue.
[0082] FIG. 8 is a block diagram of a focused ultrasonic neural stimulator system.
[0083] FIG. 9 a is a representation of a prior art technology, ultrasound phased array beam intensity.
[0084] FIG. 9 b is a representation of a prior art technology from Olympus NDT, ultrasound phased array, used to form a focal point of ultrasound energy; depicted showing the wavefronts at four times after the wavefronts have left the transducers; the bottom ones showing how they meet at a central focal point.
[0085] FIG. 9 c is a representation of a prior art technology from Olympus NDT, ultrasound phased array, used to form a focal point of ultrasound energy; depicted showing the wavefronts at four times after the wavefronts have left the transducers; the bottom ones showing how they meet at an eccentric focal point.
[0086] FIG. 9 d graphically shows the delay values used in a 32 element ultrasound phased array that are used to create different focal depths.
[0087] FIG. 9 e illustrates different focal depths that are created below a 32 element ultrasound phased array by using the delay values of FIG. 9 d.
[0088] FIG. 10 a illustrates the intensity (as determined by Shafiri et. al. of the University of Tehran) that can be achieved at a single focus using a planar array of ultrasound elements.
[0089] FIG. 10 b illustrates on possible orientation of ultrasonic transducers in a planar phased array.
DETAILED DESCRIPTION OF THE INVENTION
[0090] Patent Application 61/012,851 is included by reference.
Supra-Threshold Spot Adjustment
[0091] Without desiring to be held to any particular theory or mechanism of action, it is currently contemplated that stimulation (or capture) of the correct tissue is very important to eliciting the desired response. It is also contemplated that another important factor is doing so without stimulating too much neighboring or intervening tissue. Preferred embodiments of the present invention achieve this by creating a supra-threshold high intensity region remote from the energy emitter, and the energy intensity in the intervening region is sub-threshold. The supra-threshold region is located several millimeters away from the energy emitter interface with the body. In especially preferred embodiments this is accomplished with focused ultrasound energy or with overlapping or interfering ultrasound beams. The location of this supra-threshold spot must be adjustable—upon initial placement and on occasion when there is need to reposition due to loss of capture, or when there is need for optimization or when there is a desire to stimulate other tissue. This adjustment can be done electrically, mechanically, electromechanically or equivalent.
[0092] Electrical adjustment of the high intensity spot position can be done by choosing which group of ultrasound crystals to energize from among several to create a high intensity region achieved by overlapping beams as illustrated in FIGS. 1 through 5 . These figures illustrate a transducer head which can be placed on the skin close to directly over the target tissue. The transducer housing is placed as accurately as possible so that the high intensity spot is close to right over the target tissue—likely to be 10 to 20 mm beneath the skin surface.
[0093] In these figures, nine discrete crystals are used—selecting the proper combination of three of these allows the user to select from among five points that surround a central location. These neighboring regions can be overlapping. One point is directly above, and one point is directly below the central target. The other 3 points are in a plane between the upper and lower point, and they surround the center. Since the five points are neighboring, perhaps even overlapping, the high intensity region can be moved up or down, side to side or forward or back without moving the transducer head mechanically at all.
[0094] Alternatively, the electrical spot location adjustment could use a different number of overlapping beams. Using just two beams makes it practically simpler to define many more high intensity spots—though there would not be as distinct and abrupt intensity differentiation from surrounding tissue. Using more overlapping beams improves the resolution of the high intensity region—i.e. the overlapping region has a much higher intensity than the environs and therefore there is even less likely to be inadvertent ancillary stimulation.
[0095] Other embodiments for creating an adjustable high intensity spot mechanically move an ultrasonic focal spot. An example of this is the gimbal mounted focused ultrasonic crystal depicted in FIG. 6 . The high intensity region is at a fixed distance from the crystal. This spot is adjusted by the gimbal mechanism—and can be adjusted by the patient or the practitioner. There are three controls which allow adjustment in each of the three principal directions to achieve nearly infinitely variable location of the focal spot. The gimbal is adjusted by independent rotation of levers that control rotation about two perpendicular axes, and by a third adjustment that uses a helical track to adjust height. Rather than a gimbal, the adjustment can be accomplished by other equivalent apparatus such as x, y, z positioner.
[0096] The gimbal can be designed to allow Cartesian (x, y, z), polar (θ, φ, r) or other equivalent positional translation. The adjustment controls can be mounted (i) directly on the gimbal mount, or alternatively (ii) mechanically coupled though located remotely, as a joystick at the end of a cable for easier patient control, or alternatively (iii) located remotely, by radio control of three separately addressable motors, or (iv) an equivalent control system.
[0097] Another alternative to allow for adjustment of the high intensity supra-threshold spot is a variable focus mechanism instead of a fixed focus one. Some of the ways to achieve the variable focus are: the spacing of multiple focusing elements can be adjusted, the density of the lens can be adjusted, the shape of the lens can be adjusted, the location of elements of the transducer can be adjusted, or equivalent.
[0098] Another alternative to create an ultrasound focus is to use phased array technology as depicted in FIG. 9 . Not only can this technology be used to create a focus, but it can also be used to move the focus up or down, forward or back, left or right within a zone beneath the array. FIG. 9 b depicts how a phased array can be used to pulse each crystal using variable, but symmetric timing to form a focal point directly beneath the center of the array. FIG. 9 b depicts how the crystals of the same array can be pulsed with eccentric delays to form a focal point that is located eccentrically. Using similarly “shaped” delays of different magnitudes, the focus can be shifted variably up or down as well as left or right. FIGS. 9 d and e illustrate how different delays can shift the focal depth deeper or shallower.
[0099] Using additional array elements positioned in a different plane, e.g. an orthogonal plane, a shaped phase delay can shift the focus in an orthogonal direction. Adjusting the delays to each of the crystals within such an array will allow essentially infinitely variable focal adjustment beneath the array.
[0100] Use of a phased array of multiple elements arranged on a surface (rather than just in a line) as in FIG. 10 allows for movement of the focus left or right, up or down and forward or back. Within a volume underneath the surface array, the focus can be adjusted to be virtually anywhere. The array surface may be flat or not.
[0101] In yet another alternative embodiment of an array of energy emitters to create a focal region that can be adjusted, the array elements would be electrodes rather than ultrasonic emitters. In a similar manner, the timing of the application of voltage to each electrode would be adjusted to allow for creation of a region of high intensity at a location remote from the electrode array. Ideally, the timing of the application of voltage to each electrode would be adjusted to allow for adjustment of the location of the high intensity, supra-threshold region in space; ±X, ±Y, ±Z.
Automatic Adjustments
[0102] During the course of operation, it is likely that the stimulation of the target spot becomes compromised. The desired tissue stimulation may no longer be achieved because of threshold change or positional change. Either way—the pulsing that was once effective would be effective no longer. Adjustments could be made to spot location or pulse characteristics to recapture the target tissue. The adjustments could be made by the patient or by a practitioner or by the neuro-modulation system. It could be most convenient, prompt and accurate if the adjustments to spot location and pulse characteristics were done automatically by the system—transparent to the patient.
[0103] In order to make the adjustment automatically, it is necessary to be able to detect capture of the target tissue—i.e. a sensor that is an indicator of efficacy. The indicator could be an action potential sensor, an EMG or equivalent. One example of such a capture sensor is an electromyogram (EMG). As an example, a patient experiencing pain is likely to feel tense. This tension would often be expressed as contraction of muscles; and this muscle contraction can be detected by EMG, preferably non-invasively. Relief of the pain by successful capture could be expressed as relaxation of the contraction of indicator muscles. The effectiveness of the neuro-stimulation would result in relaxation of the muscles, and this would be reflected in the EMG sensor.
[0104] Electrical characteristics of the pulse can be modified while monitoring the indicator EMG. A decline in the indicator EMG frequency is an indication of successful capture.
[0105] Similarly, the system can alter the position of the high intensity pulse while monitoring the indicator EMG; decline in EMG frequency indicates successful capture of the right tissue.
[0106] The muscle group to serve as source of the EMG indicator could be individualized for each patient. The muscle group could be located near to the location of the perception of the pain source. For example, in a patient that experiences pain radiated in the foot, the EMG electrodes could be place on the foot. Alternatively, a more general selection—such as the trapezius muscle may be a good indicator for most patients. Relaxation of this muscle would be an indication that the perception of pain has subsided—and that the stimulation parameters are adequate.
[0107] The feedback could be binary or analog. In other words, in a binary system, feedback could be used to indicate whether the neurostimulation system has achieved capture or has failed to capture. In an analog system, the feedback would be used qualitatively to indicate how effective the stimulation treats the symptoms.
[0108] After manual determination of a baseline threshold, location and adequate sensor for feedback, the automatic adjustment process can be initiated. Capture detection can be automatically checked and adjusted periodically—for example once every 5 minutes. To check for capture and for optimization, each of the following parameters could be incremented to check for improvement of degradation of performance as indicated by the sensor response:
[0109] Ultrasound Power
[0110] Ultrasound Intensity
[0111] Ultrasound Frequency
[0112] Ultrasound Waveform
[0113] Pulse Envelope Shape
[0114] Pulse Duration
[0115] Pulse Repetition Rate
[0116] X position
[0117] Y position
[0118] Z position
[0119] This adjustment of aim and intensity of the stimulating waveform could be performed frequently to allow for refinement in stimulation in response to patient position, activity level, sympathetic tone or acute intensification of perceived pain.
Settings
[0120] The settings of energy, timing and position may be adjusted within a very large range. In a preferred embodiment, the energy source is ultrasonic; the peak power is 10 watts; the power intensity in the high intensity region is 10 the fundamental resonant frequency is 1 MHz; the repetition rate is 50 Hz; the pulse duration is 2 milliseconds; the focal point is 15 mm sub-dermal.
[0121] The waveform may be a simple sine wave or a complex waveform. The envelope of the repetition pulsing may be square or more complex. The amplitude could ramp up or down for example during the course of a pulse.
[0122] The pulsing frequency is chosen so that there is enough transmission so that there is enough penetration into the flesh to the desired target level. It is also chosen so that enough energy is absorbed so that there is tissue excitation.
[0123] The system may be used continuously to stimulate; alternatively, the system is quiescent for periods. The timing of stimulation and quiescence may be programmable. Ideally, the stimulation is maximized during periods when especially needed, for example when trying to get to sleep. It would be minimized when not needed as much, for example when the patient is already asleep. It may be programmed automatically to be quiescent for periods, such as for 40 minutes of each hour.
[0124] Though the stimulation has been described as fairly regular, it need not be. The pulse duration may be variable for example. Particular pulse durations and pulse duration intervals may be suited to particular applications.
Applications
[0125] The non-contact neural stimulation device invention can be used for any of several different applications. It can be used in the treatment of pain in a manner similar to spinal cord stimulation (SCS). Just as with SCS, supra-threshold stimuli can be delivered to neural tissue to create a tingling sensation that blocks or inhibits the perception of pain. The current invention has several significant advantages and some limitations with respect to SCS. One major advantage is that it does not mandate invasive surgery. For this application, the ultrasonic transducer would be located on the skin of the back near the spinal cord. The bony structures of the spine partially obscure ultrasonic energy access to the nerves within the cord—but there is still access.
[0126] SCS generally stimulates the nerves along the dorsal horn of the spinal cord. Stimulation of deeper nerves is not practical with SCS unless the SCS lead and electrodes are placed within the cord itself (entailing extra risks and complications). An important advantage of the present invention is that it is not limited to stimulating only the most dorsal surface of the spine. The present invention may be used to stimulate within the spinal cord without stimulating the dorsal surface. This makes possible many other neural stimulation targets that are not typically accessible by SCS.
[0127] Targeting neural stimulation targets within the spinal cord can be even more precisely achieved with the ultrasonic transducer placed even closer to the target nerves. In one embodiment, the ultrasonic transducer is implanted within the body close to the spinal cord. A high intensity supra-threshold region is created in front of the transducer spaced apart from it. This invasive application of the present invention allows for more precise targeting of excitable tissue than SCS does. A focused ultrasonic transducer of the present invention can create a supra-threshold region more precisely than the SCS electrical stimulation. The supra-threshold spot can be smaller and the intensity relative to the surrounding tissue can be more dramatic compared to SCS.
[0128] The present invention may also be used to target excitable tissues in other areas for other applications. It many be used to excite nerve roots near to where they exit the spinal cord. It may be used to excite peripheral nerves for applications analogous to peripheral nerve stimulation. These include treatment of craniofacial neuropathic pain or restoration of motor functions in patients who have experienced stroke or spinal cord injury. Stimulation of the occipital nerve for example is a way to treat migraine headaches. Other applications include treatment of angina symptoms, urinary incontinence, etc.
[0129] Because the present invention can stimulate excitable tissue remotely, it may be used to stimulate cardiac tissue. It can be used to pace the sinoatrial node, the atrioventricular node, myocardial tissue or equivalent. It could be useful as a way to quickly, easily and non-invasively provide emergency cardiac pacing.
[0130] Other applications include stimulation of other anatomical structures. An example is stimulation of excitable structures associated with the stomach and other organs of digestion to elicit a sensation of satiety for the purpose of bariatric treatment.
[0131] Other applications include stimulation of other nerves for systemic influence. Cardiac, Vagus or other nerves can be stimulated. Applications could be treatment of anxiety, depression, hypertension, etc.
[0132] Thus, specific embodiments and applications of non-invasive neural stimulation have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. | The present invention is a system for the non-contact stimulation of excitable tissue. A primary purpose is reducing the perception of pain in those people who suffer from persistent pain. Apparatus is described for adjusting the position of the stimulation region. | 0 |
TECHNICAL FIELD OF THE INVENTION
The present invention involves a device and method for its use in the removal of contaminants from a gas cylinder valve assembly. Both vacuum and purge techniques are employed at high efficiency.
BACKGROUND OF THE INVENTION
It has become increasingly important in a number of various and diverse industries to have access to ultra high purity process gas supply systems. For example, in the semi-conductor industry, as integrated circuits or similar components become smaller in size, in the micron or submicron ranges, thin film etching processes require gases of ultra high purity. Without a reliable reaction environment for film making and etching, repeatable results are not always achievable.
Although there is ample supply of UHP gases, it is common to experience the introduction of ambient contaminants during cylinder change-out. As noted, these contaminants and their reaction products with process gases can significantly degrade the performance of any UHP gas system.
The problems discussed above are certainly well known and appreciated. In fact, it is common practice to purge ambient contaminants after cylinder change-out and before opening the cylinder valve. In this regard, reference is made to FIG. 1 which depicts three known purging techniques, namely cross-purge, deep purge and vacuum purge.
FIG. 1(A) depicts a typical cross-purge configuration whereby UHP gas cylinder 1 containing high purity gas at high pressure is fed through control valve/cylinder connection 2. Typically, gas travels through a process line depicted by "pigtail" 6 for feeding a process gas through valve 5. Purging takes place by closing valve 2 and applying the purge gas through valve 3 which is exhausted through exhaust valve 4. Although this process provides for some contaminant removal, too much "dead volume" is left in "pigtail" 6 and cylinder connection 2 to adequately remove sufficient contamination.
FIG. 1(B) depicts what is known as a deep purge procedure whereby UHP gas cylinder 11 is functionally attached to connector 12 which further embodies valve 13 for the introduction of purge gas through line 16 and exhaust valve 14. Deep purge provides improved contaminant removal in light of purge gas introduction through valve 13 at connector 12. As such, deep purge eliminates the "dead volume" in the "pigtail" and particularly in the cylinder connection itself. By maintaining process valve 15 in a closed condition, purging is generally accomplished by several pressure cycles, that is, by opening and closing exhaust valve 14, line 16 can be pressurized and depressurized. In doing so, deep purge is effective in removing contaminants in the "dead volume" of the cylinder connection but is not effective in removing contaminants adsorbed on the surface of components. Another problem with the deep purge process is that it is not possible to protect the cylinder valve connection from ambient contaminants by flowing an inert gas through the connecting pieces during cylinder change out.
The present state of the art purge techniques are shown in FIG. 1(C). In this instance, UHP gas cylinder 21 feeds gas to line 26. However, purge gas introduced through valve 22 is employed in conjunction with vacuum generator 23. Purge gas is admitted to line 26 while both vacuum valve 24 and process valve 25 remain in a closed condition. After purge gas pressure buildup, valve 24 is opened and vacuum generator 23 employed to exhaust the purge gas from line 26.
Even the configuration depicted in FIG. 1(C) is not without its drawbacks. Specifically, it has been found that vacuum generator 23 is simply too far from cylinder 21 and its cylinder connection where contamination occurs. The effectiveness of vacuum purge degrades significantly with distance especially for adsorbing species such as moisture. In addition, a vacuum generator increases costs as well as the physical dimension of the purge unit contributing to the complication of system operation.
It is noted that most semi-conductor processing gases, such as those recited in U.S. Pat. No. 4,917,136 are introduced through flow restricting orifices installed in cylinder valve assemblies for safety purposes. Deep purge, cross purge and vacuum purge will not effectively remove contaminants from such flow restricting orifices.
It is thus an object of the present invention to provide a device for purging cylinder valve assemblies more effectively than those employed by the prior art as discussed above.
It is yet a further object of the present invention to provide a device for the removal of contaminants from a gas cylinder valve assembly having fewer parts and being less complex than devices used for the same purpose as discussed above.
These and further objects will be more readily appreciated when considering the following disclosure and appended claims wherein:
FIG. 1, previously discussed, depicts, in schematic, three prior art approaches to the problem of contaminant removal;
FIG. 2 depicts one embodiment of the present invention in cross-section;
FIG. 3 is a graphical depiction of the relationship between vacuum pressure created in the operation of the present invention as a function of purge gas pressure;
FIG. 4 is a graphical representation of the relationship between the calculated concentration of non-adsorbing species versus the number of purging cycles in practicing the present invention;
FIG. 5 is a further graphical representation of the relationship between dead space pressure measured as function of purge gas flow rate at different internal dimensions of the present invention; and
FIG. 6 is yet another embodiment shown in cross-section of the device of the present invention.
SUMMARY OF THE INVENTION
The present invention involves a device and method for its use in the removal of contaminants from a gas cylinder valve assembly. Such assemblies are configured with an inlet for connection to a gas cylinder and an outlet for connection to fittings for receiving the contents of the gas cylinder.
The device itself comprises a purge gas inlet having a first orifice cross-section, a purge gas outlet having a second orifice cross-section and a third orifice connecting the first and second orifices. The third orifice is characterized as having a reduced cross-section in comparison to the first and second orifices.
A fourth orifice is provided joining the gas cylinder valve assembly outlet at its proximate end while joining the second orifice at its distal end. The distal end of the fourth orifice is located at a point where the second and third orifices meet noting that at that point, the fourth orifice is provided with a reduced cross-section.
DETAILED DESCRIPTION OF THE INVENTION
The invention can perhaps best be appreciated with reference to FIG. 2 whereby device 10 is shown in cross-section. Specifically, fourth orifice 35 shown in a generally vertical orientation is intended to be connected to a gas cylinder valve assembly (not shown). It is this assembly which is intended to be purged of contaminants. Generally, such purging is done at start-up or when breaking into a system for repair and maintenance and when changing cylinders. The purge gas is introduced within first orifice 31 in a direction shown by flow arrow 38. The purge gas can consist of any gaseous material inert and unreactive with the process being contemplated and process gases being employed. Generally, nitrogen is considered appropriate for most applications.
Purge gas introduced at open end 34 passes through the device of the present invention and exits through second orifice 33. First orifice 31 and second orifice 33 are connected by a third orifice 32 which, as noted, is provided with a reduced cross-section. Fourth orifice 35, as noted, is connected to a gas cylinder valve assembly at its proximate end 39 and is joined to second orifice 33 at its distal end 40 which is characterized as having a reduced cross-section.
In operation, the cylinder valve (not shown) and exhaust valve located along second orifice 33 (not shown) are closed and the purge valve (not shown) is opened allowing purge gas to enter the present device. An exhaust valve located within second orifice 33 can be periodically opened and closed thus altering the pressure within the device at will. Purge gas flowing through the first, second and third orifices create a vacuum within the fourth orifice, the extent of the vacuum being a function of purge gas pressure. In this regard, reference is made to FIG. 3 for the relationship between pressure achieved within the fourth orifice measured as a function of purge gas pressure. It has been found that the purge gas pressure should be increased typically to approximately 8 bar or more in order to create a vacuum within orifice 35 of approximately 200 torr or greater. This pressure in turn is imposed upon the "dead volume" of the cylinder connection.
The repeated cycling of purge gas pressure increase and release significantly improves the efficiency of contaminant removal from the gas cylinder valve assembly. In this regard, reference is made to FIG. 4 where the concentration of non-adsorbing species within this assembly was calculated with respect to purging cycles at a purging pressure of 105 psia creating a vacuum pressure of 2 psia.
As noted previously, many gas cylinder valve assemblies, particularly those employed in the introduction of processing gas to semiconductor thin film manufacturing, are provided with flow restrictors which are virtually impossible to decontaminate. As a further advantage of practicing the present invention, such flow restrictor devices can be completely eliminated from such gas cylinder valve assemblies for the present device in employing its fourth orifice of reduced cross-section at its distal end acts as a suitable flow constrictor which obviously suffers from none of the contamination shortcomings of prior devices.
In that the vacuum is created within orifice 35 and in turn within a suitable gas cylinder valve assembly through venturi effects created by the relative location and geometry of the various orifices, it is not surprising that orifice size and orientation are critical in optimizing the present device. Specifically, it has been found that orifice 32 having a generally cylindrical configuration and circular cross-section should be provided with a radius of 0.027 inches ±0.003 inches. Similarly, orifice 36 located at the distal end of orifice 35 should also be of a substantially cylindrical configuration having a radius of 0.020 inches ±0.005 inches. As noted, location is also critical. Specifically, orifice 32 transitions into orifice 33 in a ramp fashion forming a frustum of a cone at 38. To optimize performance, orifice 36 is positioned such that its center line 37 is located 0.020 inches ±0.005 inches from the beginning of the conical transition from orifice 32 to orifice 33.
In confirming the criticality of the above-recited physical dimensions and spacial positioning between the various orifices, experimental data was generated as graphically presented in FIG. 5. Specifically, the source pressure of the purge gas was varied creating a venturi-induced vacuum within the "dead space" of a typical gas cylinder valve assembly. In interpreting FIG. 5, "A" is the radius of orifice 32 while "H" is the radius of orifice 36. L is the measured distance between center line 37 and the beginning of the transition between orifice 32 and orifice 33. Quite obviously when operating within the physical dimensions recited previously, the efficiency of the vacuum created within the "dead space" of a gas cylinder assembly increases dramatically as a function of purge gas flow rate.
The device shown in FIG. 2 can be modified while remaining within the spirit and scope of the present invention. Obviously, since there are a wide variety of cylinder valves available which have various dimensions for the fourth orifice the optimum dimensions will change. The general design can be used for the other cylinder valves, however, and optimum dimensions for the first, second and third orifices determined. For example, FIG. 6 depicts a typical modification which, in some instances, enhance the overall efficiency of the present invention. As noted, although first orifice 61 and third orifice 62 are similar to their corresponding components 31 and 33 of FIG. 2, second orifice 66 is provided with a throat of reduced dimension 67. This obviously would increase purge gas flow rate and thus the efficiency of venturi-created pressure within fourth orifice 63. It is further noted, where FIG. 2 shows an abrupt step within orifice 4 when progressing to its distal end of reduced cross-section 36, this transition between the body of fourth orifice 63 and its distal end of reduced cross-section 64 can be ramped as shown as element 65. As noted, other modifications can also be made while remaining within the spirit and scope of the present invention which is to be limited only by the appended claims. | A device and a method for its use for the removal of contaminants from a gas cylinder valve assembly. The valve assembly output is fed to the device which in turn has inlet and outlet connections to receive and to pass purge gas therethrough. The device is sized and positioned so that contaminants can be purged and a vacuum drawn from the gas cylinder valve assembly at the assembly location itself thus increasing the efficiency of contaminant removal. | 8 |
This invention relates to a safety system on a skid steer loader which utilizes a safety shield or safety bar connected to a parking brake actuator and also arranged to prevent operation of the hydraulic foot-controls when required.
BACKGROUND OF THE INVENTION
In a skid steer loader and in other similar types of construction, farm and logging equipment there is a parking brake which is operated directly by the operator and there are also hydraulic controls which are foot operated for controlling the hydraulic boom and bucket cylinder actuators. When an operator has to enter the loader, he has to step onto various parts of the equipment in order to reach the operating position. There is always the danger, when entering or leaving the loader, that the operator will accidentally step upon the brake or hydraulic controls. Furthermore, the parking brake, although it should always be set when leaving the loader, is sometimes inadvertently left in its off position and, as the engine of a loader is normally left operating during most of an operating shift even when the loader is left inactive for short lengths of time, the vibration will sometimes cause the loader to move.
SUMMARY OF THE INVENTION
In this invention there is provided in one aspect, a parking brake which is operated by a combined foot rest and safety shield. When the operator is outside the loader, the safety shield and foot rest is in a horizontal position and in this position automatically sets the parking brake. The foot rest and safety shield also is positioned above the hydraulic boom and bucket controls so preventing accidental operation of the actuators. When the operator wishes to climb up into the operating position on the loader, he steps upon the foot rest and safety shield and when wishing to operate the loader lifts up the safety shield into an upright position which automatically releases the parking brake and also exposes the hydraulic controls. When the safety shield is in the upright position, it also acts as a rock guard for the operator's legs.
In another aspect of the invention, as well as the safety shield and foot rest, a safety bar is used which can be raised upwardly for operator entry and exit and can be lowered for protection purposes when the operator is in position. This safety bar is connected through linkage which operates the safety shield and foot rest; the parking brake, and also a lock for the machine drive. A safety start switch is also operated by the safety shield so that the engine cannot be started unless the safety shield is in its lowered position which means that the safety bar is its raised position, the machine drive is locked in the neutral position and the parking brake is set.
In a further aspect of the invention, where there is a lack of space as in a small loader, the safety shield of the last aspect, is dispensed with and the safety bar is connected to a locking lever which prevents movement of the hydraulic foot controls and the parking brake.
Embodiments of the invention will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevational view of a skid steer loader incorporating this invention.
FIG. 2 is a diagrammatic view of the inventive part of the apparatus of FIG. 1 with the safety shield in upright position.
FIG. 3 is a diagrammatic view of the novel part of FIG. 1 with the safety shield in lowered position.
FIG. 4 is a diagrammatic side elevational view of another type of skid steer loader.
FIG. 5 is a diagrammatic view of the cab part of the skid steer loader of FIG. 4 showing the safety shield in lowered position,
FIG. 6 is a diagrammatic view of the cab part of FIG. 4 showing the safety shield in upright position, and
FIGS. 7 and 8 are diagrammatic views of another embodiment of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown diagrammatically a skid steer loader which has a boom 1 pivotally secured to a frame member 3 and operated by an hydraulic boom actuator 5. The boom 1 has an extension 7 upon which a bucket 9 is pivotally attached and is operated by an hydraulic actuator 11. A brake disk 13 is secured to an extension shaft 15 from the end of the transmission (not shown), and a brake caliper mechanism 17 is secured to the frame through a bracket 18. The brake mechanism 17 is operated through a cable 19. Details of the brake caliper mechanism are not shown as any known mechanism will suffice, such being well known in the field.
A flat plate 21 is pivotally mounted along one edge, through a hinge 23, to the frame of the loader and is capable of movement between a lower position shown in full lines and an upright position shown in broken lines. The end of the cable 19 is secured with the outer wire sleeve on a bracket (not shown) and the inner wire around a small actuating disk 25 which rotates with the plate 21. Beneath the plate 21 there are the normal hydraulic controls for the boom and the bucket which utilize foot pedal means 27 and operating valves 29.
When the operator leaves the loader, he opens a latch, of any well known design, which holds the plate 21 in upright position and lets the plate fall to a lowered position. He then stands upon the plate 21 which sets the brake through the cable 19, and the plate snaps below a latch, of any known design to hold the brake in set position. He then uses plate 21 as a foot plate and steps from it to the ground. Note that when the plate 21 is in its lowered position, it is not possible for the operator to inadvertently stand upon the foot pedal means 27 as it is completely shielded. To climb up again into the loader, the operator uses plate 21 as a foot rest, and after sitting in the operator's seat, opens the latch which holds the plate 21 in lowered position, lifts the plate into an upright position and pushes it behind the upper latch. He can then operate the foot pedal means 27 while the plate 21, in its upright position, acts as a stone guard.
Referring to FIGS. 2 and 3, diagrammatic views show only the operating part of the invention, plate 21 being shown in upright position in FIG. 2 and in lowered position in FIG. 3, and in these two Figures there is utilized a lever and rod mechanism 31 for operating the brake caliper mechanism 17.
FIG. 4 shows a different type of skid steer loader which, however, has the same basic elements as the loader in FIG. 1. The loader of FIG. 4 has a frame 33, a boom 35, an hydraulic boom actuator 37, a bucket 39 and an hydraulic bucket actuator 41.
FIGS. 5 and 6 show enlarged views of the internal components in the cab 43 which provide more safety features than those outlined in the embodiments of the invention shown in FIGS. 1, 2 and 3.
Specifically, there is a shield and foot rest 45 which is hinged at 47 to a member 49 of the frame. A safety start switch 51 which can be of the plunger type is mounted upon a bracket 53 and is wired into the starting circuit to only permit starting of the loader engine when the plate 45 is in the lowered position. A bracket 55 is secured away from the hinge 47 and a rod 57 is pivotally secured to the bracket 55 and extends to one arm of bell crank lever 59. The other end of bell crank lever 59 has a rod 61 extending to one arm of a pivoted lever 63 to which is attached a rod 65 and a rod 67. Rod 65 actuates a brake caliper mechanism 69 upon a brake disk 71 which is secured to an extension shaft 73 from a transmission (not shown). No details of the brake caliper mechanism are provided as such are considered conventional. The other rod 67 has a roller 75 at its free end, roller 75 being capable of travelling within a channel 77 which is the lower part of pivoted drive engaging lever 79. An angled bracket 82 is secured in a fixed position so that when roller 75 is pulled downwardly in the angle bracket, the drive engaging lever 79 is made immobile.
A safety bar 81 is loosely pivoted at one end 83 and has a short rod 85 pivotally mounted at the other end. The short rod 85 is itself pivotally secured to a sleeve 87 which can slide along an upright rigidly secured rod 89. The sleeve is preferably provided with a rudimentary gripping means (not shown) which can hold the sleeve in any required position on the rod 89. Near end 83 of rod 81 there is pivotally attached a further rod 91 which is secured to an arm (not shown) of bell crank 59.
The operating pedal means 93 for activating the hydraulic central valves 95 for the boom and bucket operation, are situated below the plate 45.
When an operator enters the loader of FIGS. 4 through 6, he steps upon plate 45 and positions himself in the seat, and due to the location of plate 45 which is in the position as shown in FIG. 5, it is not possible for him to accidentally operate the hydraulic central valve 95. The prime mover of the loader can then be started, this being permitted by the switch 51 which allows activation of the starting circuit as it is closed by the plate 45 when this plate is in lowered position. After starting the prime mover, the sleeve 87 is pulled downwardly, causing rotation of rod 81, activation of bell crank 59, rotation of plate 45 to an upright position, release of parking brake 69, and release of the drive operating lever 79 by raising of roller 75 into its uppermost position. The release position of all the controls is shown in FIG. 6. Plate 45, in its upright position also provides a stone guard for the operator and also provides access to the hydraulic controls for the boom and bucket.
When the operator wishes to leave the loader, he raises the sleeve 87 which lowers plate 45, sets the parking brake 69, and locks the drive control lever 79. The lowering of plate 45 again covers the hydraulic controls 93 and 95 and plate 45 is used as a foot rest for ease in leaving the loader.
Referring to FIGS. 7 and 8, when there is a lack of space in a loader the safety shield of the embodiment shown in FIGS. 5 and 6 can be dispensed with and a safety bar 99 can be used to solely control the safety features. Safety bar 99 is pivoted at 101 and has a rod 103 which operates a bell crank lever 105 through an operating lever 107. A lower rod 109 from the bell crank lever 105 is connected to a cranked lever 111 which has a free end in contact with a downwardly spring biased locking lever 113. A horizontally extending rod 115 from bell crank lever 105 is connected to a pivoted lever 117 which has a roller 119 at its other end. This roller 119, in co-operation with angled bracket 121 operates to selectively hold the lever 123 in inoperative position as in the previous embodiment. Hydraulic foot controls 124 are shown in broken lines and operate a braking and/or other system through control valves 125, a pin 127 being used at a pivot between the foot controls and the control valves, which will co-operate with a notch 129 in the locking lever 113. In operation, when the safety bar 99 is raised, as shown in FIG. 7, lever 123 is held in inoperative position by roller 119 and angled bracket 121 and the foot controls 124 are held in a set position by lever 113.
In this position, the parking brake system would be set and the control valves would be in a neutral position. After the operator enters the loader, the safety bar will be lowered to the position shown in FIG. 8, so releasing the control valves 125 and the operating lever 123. The parking brake can also preferably be released by the safety bar movement. If required, the safety bar can operate an electrical safety switch so that the engine of the loader cannot be started until the safety bar is pulled down into operative position.
It will therefore be noted that a safety system has been disclosed which ensures the safe operation of skid steer loader so that accidental operation of hydraulic controls is not possible while the operator is entering or leaving the loader nor will the loader accidentally move as the parking brake is set until the operator is in operating position. Of course this safety system can be used with advantage in many types of logging equipment, construction equipment, and farm equipment which utilize hydraulic controls for bucket or grader operation.
The invention will be limited only by the scope of the claims which follow. | A safety system for a vehicle having foot operated hydraulic controls consisting in one embodiment of a safety shield which activates a parking brake so that when the shield is in a lowered position the parking brake is set and the shield covers the hydraulic controls of the vehicle as well as being a foot rest, and when the shield is in upright position, the parking brake is released and access is obtained to the hydraulic controls; and in another embodiment of a safety bar which activates a locking lever which prevents operation of the foot controls when the safety bar is raised and permits operation of the foot controls when the safety bar is lowered. | 1 |
BACKGROUND AND SUMMARY OF THE INVENTION
In the past, fabrication of visible or near infrared transmitting glass (silica) fibers with a suitable cladding has been advanced by several manufacturers. The cutoff wavelengths for glass fibers, however, precludes its use for infrared transmission. The publication "Polycrystalline Fiber Optical Waveguide for Infrared Transmission" by Pinnow, Gentile, Standke and Timper, Applied Physics Letter 33(1), July 1, 1978, Pages 28-9, describes fiber optic waveguide cores of polycrystalline thallium bromide and thallium bromoiodide (KRS-5), the cores being inserted into a loose fitting polymer cladding. These materials have some solubility in water however, which is a disadvantage.
In the present invention, an infrared optic fiber is described in which both the core and the cladding of the optic fiber are of a halide material and the clad fiber is fabricated by an extrusion procedure. In one example, silver chloride (AgCl) clad silver bromide (AgBr) is described. AgCl and AgBr are virtually insoluble in water which is a strong advantage. The fundamental phonon absorption bands are in the far infrared making them a good choice. Furthermore, at elevated temperatures, halide materials become plastic and deform in a manner similar to metals. Consequently, it is possible to perform metal-like working operations on them such as extrusion, rolling and forging. In order to produce a fine-grained polycrystalline material by deformation of a single crystal or polycrystal billet, the billet must be at a temperature high enough to permit a generalized deformation. This temperature should not be so high, however, that substantial grain growth occurs, since the desired result in the extruded fiber is a fine-grained material. In AgCl the preferred temperature range is between about 20° C. and about 300° C. and in AgBr the preferred temperature range is between about 15° C. and about 300° C. Fiber extrusion at room temperature (about 20° C.) has proved feasible to provide a fine-grained optical fiber of AgCl clad AgBr.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a geometrical representation of a AgBr fiber clad with AgCl.
FIG. 2 is a diagrammatic sketch of extruding apparatus to produce the fiber of FIG. 1.
FIG. 3 is a graphical presentation of grain size vs. temperature in a AgCl extrusion. The shaded region indicates that the result also depends on extrusion rate in the range given in Table II.
FIG. 4 is a photograph of the AgCl clad AgBr fiber.
DETAILED DESCRIPTION
Infrared transmitting fiber optics are useful for infrared image and signal transmission. FIG. 1 discloses a new infrared fiber 10 having a AgBr core 11 and a AgCl cladding 12 for use in such IR work. At 10.6 μm wavelength, the refractive index of these two materials are 2.0 for AgBr and 1.98 for AgCl resulting in a clad fiber of a numerical aperture (NA=√2·nΔn) of approximately 0.28 and is suitable for many image and signal transmission applications. Table I shows a summary of optical properties of these halide materials.
TABLE I______________________________________SUMMARY OF OPTICAL PROPERTIESOF HALIDE MATERIALSMa- Transmission Refractive Absorption Crystalterial Range (μm) Index* Coeff. (cm.sup.-1) Structure______________________________________AgCl .5-20 1.98 .005 Cubic (NaCl)AgBr .5-25 2. .005 Cubic (NaCl)______________________________________ *At 10.6μm wavelength
Thus, it can be seen that both materials operate into the IR range and that they both have the NaCl type of cubic crystal structure.
Experimental measurements indicate that the optical loss in the fiber is strongly dependent on the grain size. Generally, the smaller the grain size, the lower the fiber loss. Therefore, it is essential to be able to control the fiber grain size. Fine grain size is herein defined as less than about 20 microns and preferably about 1-3 microns. To perform the extrusion we have constructed a differential pressure extrusion machine, with a capability of up to 400,000 pounds/inch squared pressure in the extrusion chamber which can be heated to the desired temperature. The speed of extrusion is also controllable with high precision. The machine allows extruding of silver halides even at room temperature.
In FIG. 2 there is shown apparatus for extruding the clad optic fiber 10. A diamond die 20 in a die holder 21 is affixed to a cylindrical container 22 which encloses the coaxial billet 23 to be extruded when a force F is applied at ram 24. For example, we have used dies sized to extrude fibers from 3 to 18 mils in diameter. In the case of an extruded clad fiber such as is shown in FIG. 1, the coaxial billet 23 comprises a cylindrical body or sleeve of AgCl surrounding a rod or core of AgBr snugly fit within it. In one laboratory example, this preformed billet comprised a single crystal AgCl billet which was axially drilled out to a diameter to receive a AgBr single crystal core section. In this example the AgCl sleeve had an outer diameter of 1/4" and was drilled out to receive a 1/8" AgBr core section. The preform billet is oriented in the press to axially align the core and sleeve in the direction of extrusion. The resulting extruded clad fibers are found to be fine grain polycrystalline in nature, with the average grain size being strongly dependent on extrusion temperature, extrusion rate and other preparation conditions. The ratio of core to cladding of the billet is generally followed in the extruded fiber. A range of temperatures and extrusion rates have been used in the extruding process and the graph of FIG. 3 demonstrates the dependence of the grain size for AgCl as a function of the extrusion temperature. The lower temperature areas of the graph are to be preferred. It is also found that in order to achieve fine-grained (˜1-3/μm) fibers a low extrusion rate is desirable. Table II shows extrusion variables which have been tried for AgCl and AgBr including extrusion rates, pressure and temperature, the die diameter, the light transmission loss at 14 μm and the cutoff wavelength.
While extruding a preformed billet comprising a AgBr core and a AgCl sleeve into a cladded fiber has been described in detail, it is also possible to coat, indiffuse, or deposit AgCl over the AgBr fiber.
TABLE II__________________________________________________________________________INFRARED FIBER EXTRUSION EXPERIMENTS TRANSMISSION CUT-OFF DIAMETER RATE PRESSURE TEMPERATURE AT 14μM WAVELENGTHMATERIALS (MILS) (IN/MIN) (PSI) (°C.) (DB/CM) (μM)__________________________________________________________________________AgCl 6-18 0.2-25 260,000 to 20-310 0.06-1 20 280,000AgBr 10-18 0.3-25 260,000 to 15-315 .045-1 28 280,000__________________________________________________________________________ | An infrared fiber of a silver chloride clad silver bromide core fabricated by an extrusion process in which both core and cladding are extruded. | 2 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to the field of well bore packing tools (otherwise known as packers), and more specifically to expandable packers and methods of using same in various oil and gas well operations.
2. Related Art
Expandable or inflatable packers are well known in the oil industry and have been used for decades for zone isolation, gas/oil ration control, straddle pack services, formation treating, testing and similar operations. These packers are used to block the flow of fluids through the annular space between the pipe and the wall of the adjacent well bore or casing by sealing off the space between them and are placed in a well bore to isolate different zones of interest or production.
Most of the current expandable packers are made with an elastomeric membrane for sealing supported on a metallic structure for mechanical strength. Current expandable packers are assemblies of many different elements such as steel cables, nipples, skirts, and fiber support layers, the latter comprising materials such as the polyaramid fibers known under that trade designation Kevlar™, available from DuPont, for anti-extrusion mechanically joined to an elastomeric packer element. Some constructions provide an integral composite body allowing the integration of fiber support or metal slats within the integral body to provide extrusion resistance and strength (see for example assignee's copending application Ser. No. 11/257,565, filed Oct. 25, 2005). Since the expansion support is achieved by the laminar location of the support fibers or slats, the mechanical connection to these supporting structures is minimized and the strength of the packer is enhanced. Expandable packers of this design may be composed of an inner sealing member, an integrated mechanical structure, and an outer elastomeric layer for sealing. The support system can be made entirely of a composite material and thus integrates the mechanical support elements within a laminar structure of the composite body.
Although these improved designs decrease extrusion of the inner elastomeric member, further problems remain. One problem manifests itself at high temperatures, where the inner rubber layer may be prone to extrusion through any mechanical structure when the packer is inflated. For expandable packers having slats, the slats generally provide good protection against extrusion of the underlying elastomer through the slats, however, the elastomer may exhibit unacceptable dimension recovery after inflation and deflation due to the slats' permanent deformation, and high friction coefficient between slats, making the inflation/deflation difficult at high hydrostatic pressure. Cable packers do not have the permanent deformation problems, and inflation/deflation is easier, however these packers have the problem that at high temperature/high inflation pressure, the inner rubber member is likely to flow through windows existing between cables after inflation. Some means are currently used to prevent this extrusion, such as an aramid fiber layer or a layer of small diameter cables set between a reinforcement layer and the inner elastomeric member. While these may be improvements in certain environments, one problem with small diameter cables is that they do not offer sufficient coverage after packer expansion, leaving some gaps through which the elastomer can extrude. A problem with aramid fiber-based anti-extrusion layers is that aramid fibers such as Kevlar™ may become damaged by mechanical stress and/or high temperature.
Therefore, while there have been some improvements made in expandable packer deign to prevent extrusion of the inner elastomer layer, further improvement is desired.
SUMMARY OF THE INVENTION
In accordance with the present invention, expandable packers and methods of use are described that reduce or overcome problems in previously known expandable packers and methods.
Expandable packers of the invention comprise, in addition to standard non-expandable end connections, an expandable inner elastomeric member, an anti-extrusion layer, and an outer sealing member supported on a metallic structure, wherein the anti-extrusion layer comprises:
a) a fibrous layer having a first surface adjacent an outer surface of the inner expandable elastomeric member, which may be comprised of aramid fibers such as Kevlar™; and b) a cable layer adjacent the fibrous layer, the cable layer comprising a plurality of stacked unidirectional layers of cables, wherein the cable layer is adapted to assume a barrier substantially devoid of gaps through which the inner elastomer member would otherwise extrude into upon expansion of the inner elastomeric member.
In certain embodiments, the cables in the cable layer may have diameters sufficient to allow the cables to move relative to each other if necessary to form the barrier substantially devoid of gaps. The cables in the cable layer may or may not be homogenous in diameter. The diameter of the cables may range from about 0.5 to 5 mm, for example. The cables may be positioned with the same angle relative to a longitudinal axis of the packer, so that they form a homogeneous layer after expansion, without any gap between two cables. The number of unidirectional layers in the cable layer is dependant on the expected expansion ratio, but may range from two layers up to 10 layers or more if necessary. When the expansion ratio of the packer is equal or lower than 100%, two layers of cables may be sufficient. When the expansion ratio is between 100 and 200%, there may be a need for three layers of cables. Higher expansion ratios may require more than three layers of cables.
The fibrous layer is positioned between the cable layer and the inner elastomeric member. In certain embodiments the fibers making up the fibrous layer may form a unidirectional layer that has the same or different direction as the cables in the cable layer. All the fibers may be positioned side by side, with no crossing. More than one unidirectional fibrous layer may be employed. When multiple fibrous layers are employed, the fibers making up the different layers may be oriented differently; for example, the first fibrous layer may be set helicoidally, making an angle of 7° with the longitudinal axis of the packer, while other layers may be substantially parallel to the longitudinal axis of the packer. The second layer may be positioned on the first one, with a different angle. For example, this angle may be −7°. In certain embodiments, it may be useful to have additional fibrous layers with each layer having a specific angle.
When the inner elastomeric member of packers of the invention are expanded, gaps may appear between portions of the mechanical structure supporting the outer sealing member. The cables in the cable layer are pushed against this mechanical structure by inflation pressure, which creates a perpendicular force, held by the cable layer. The fibrous layer is pushed against the cable layer by inflation pressure. As the cables in the cable layer form a homogeneous layer, with no window, the fibers are stressed in transverse compression and see little or no tearing and no tensile stress. The stress on the fibrous layer is much lower than if there were no cable layer, and the expandable packers of the invention can resist much higher inflation pressure.
Expandable packers of the invention include those apparatus that may comprise a straight pull release mechanism, as well as a connector for connecting an end of the packers to coiled tubing or jointed pipe. Yet other embodiments of the expandable packers of the invention comprise an expandable packer wherein the expandable portion comprises continuous strands of polymeric fibers cured within a matrix of an integral composite tubular body extending from a first non-expandable end to a second non-expandable end of the body. Other embodiments of expandable packers of the invention comprise continuous strands of polymeric fibers bundled along a longitudinal axis of the expandable packer body parallel to longitudinal cuts in a laminar interior portion of the expandable body to facilitate expansion of the expandable portion of the integral composite tubular body. Certain other expandable packer embodiments of the present invention comprise a plurality of overlapping reinforcement members made from at least one of the group consisting of high strength alloys, fiber-reinforced polymers and/or elastomers, nanofiber, nanoparticle, and nanotube reinforced polymers and/or elastomers. Yet other expandable packer embodiments of the present invention include those wherein the reinforcement members have an angled end adjacent the non-expandable first end and adjacent the non-expandable second end to allow expansion of the expandable portion of the tubular body. Another embodiment of the present invention comprises, an expandable packer wherein the angle of the reinforcement end portions is about 54° from the longitudinal axis of the expandable packer body.
Another aspect of the invention are methods of using the inventive packers, one method of the invention comprising:
(a) running a packer of the invention to depth in a well bore on coiled tubing or jointed pipe; and (b) inflating the inner elastomeric member and causing the outer sealing member to expand against a well bore, whereby the inner elastomeric member is reduced or prevented from extruding into the support structure.
Methods of the invention include those comprising releasing the packer from the well bore, wherein the inner elastomeric members return substantially to their original shape. Other methods of the invention are those including running the packer to another location in the well bore, and repeating step (b). Other methods of the invention include prior to step (a) selecting a number of layers of cable for the cable layer sufficient to create the barrier of step (c) based on an expansion ratio expected for the packer in step (b), and other methods comprise calculating an expected expansion ratio prior to the selecting of the number of layers of cable.
These and other features of the apparatus and methods of the invention will 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 can be obtained is explained in the following description and attached drawings in which:
FIG. 1 is a schematic cross-section view of an expandable packer according to one embodiment of the invention;
FIG. 2 is a schematic cross-section view of a portion of the expandable packer of FIG. 1 illustrating an anti-extrusion layer in accordance with the invention;
FIG. 3 is a schematic sectional view of a portion of the expandable packer of FIG. 1 illustrating how an anti-extrusion layer in accordance with the invention acts during expansion to limit tensile stress on a fibrous portion of the anti-extrusion layer; and
FIG. 4 is a perspective view, with portions broken away, of an expandable packer of the invention illustrating different orientation of two fibrous layers, according to one embodiment of the invention.
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 will 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 expandable packers and methods of using same in well bores. A “well bore” may be any type of well, including, but not limited to, a producing well, a non-producing well, an experimental well, and exploratory well, and the like. Well bores may be vertical, horizontal, some angle between vertical and horizontal, diverted or non-diverted, and combinations thereof, for example a vertical well with a non-vertical component. Although existing expandable packers have been improved over the years, these improved designs have left some challenging problems regarding extrusion of the inner elastomeric member. One problem manifests itself at high temperatures, where the inner elastomeric member or layer may be prone to extrusion through any mechanical structure when the packer is inflated. For expandable packers having slats, the slats generally provide good protection against extrusion of the underlying elastomer through the slats, however, the elastomer may exhibit unacceptable dimension recovery after inflation and deflation due to the slats' permanent deformation, and high friction coefficient between slats, making the inflation/deflation difficult at high hydrostatic pressure. So-called “cable packers”, expandable packers having large diameter cables therein for structurally supporting the outer sealing member, do not have the permanent deformation problems, and inflation/deflation is easier, however existing cable packers have the problem that at high temperature/high inflation pressure, the inner rubber member is likely to flow through windows (gaps) existing between cables after inflation. Some means are currently used to prevent this extrusion, such as an aramid fiber layer or a layer of small diameter cables set between a reinforcement layer and the inner elastomeric member. While these may be improvements in certain environments, one problem with small diameter cables is that they do not offer sufficient coverage after packer expansion, still leaving some gaps through which the elastomer can extrude. A problem with aramid fiber-based anti-extrusion layers is that aramid fibers such as Kevlar™ may become damaged by mechanical tensile stress and/or high temperature, and thus degrade over time. Thus, there is a continuing need for expandable packers and methods that address one or more of the problems that are set forth above.
Referring to the drawings in detail, FIG. 1 shows a schematic diagram, not to scale, of an expandable packer of the invention having with a longitudinal bore therethrough according to one embodiment of the invention. The packer has non-expandable first and seconds ends 1 A and 1 B, and an expandable body comprised of an inner elastomeric member 2 , a fibrous layer 3 , a cable layer 4 , and a structural support 5 that supports an outer elastomeric sealing member 6 . Inner elastomeric member 2 and sealing member 6 may comprise a composite material or a mixture of composites, including one or more laminated elastomeric layers to allow expansion of the packer upon the application of internal fluid pressure. Member 2 and sealing member 6 may be constructed as a single piece of composite or multiple sections of composite material that can be layered together before curing and setting of the composite resins. The composite may be fabricated with a plurality of single fibers (not shown) extending from first end 1 A to second end 1 B longitudinally arranged around the body. The fibers may be positioned during manufacture so there is no mechanical discontinuity between the expandable and non-expandable sections of the packer. These continuous fibers inserted from a first end 1 A of the packer to the opposite end 1 B, provide substantial support to the fully expanded packer.
The expandable portion of the expandable packer is positioned between the first 1 A and second 1 B non-expandable ends of the structure. Each end 1 A and 1 B of the packer body 10 may be adapted to be attached in a tubular string. This can be through threaded connection, friction fit, expandable sealing means, and the like, all in a manner well known in the oil tool arts. Although the term tubular string is used, this can include jointed or coiled tubing, casing or any other equivalent structure for positioning the packer. The materials used can be suitable for use with production fluid or with an inflation fluid.
Elastomeric sealing member 6 engages an adjacent surface of a well bore, casing, pipe, tubing, and the like. Other elastomeric layers between the inner and outer elastomeric members 2 and 6 may be provided for additional flexibility and backup for inner elastomeric member 2 . A non-limiting example of an elastomeric element is rubber, but any elastomeric materials may be used. A separate membrane may be used with an elastomeric element if further wear and puncture resistance is desired. A separate membrane may be interleaved between elastomeric elements if the elastomeric material is insufficient for use alone. The elastomeric material of outer sealing member 6 should be of sufficient durometer for expandable contact with a well bore, casing, pipe or similar surface. The elastomeric material should be of sufficient elasticity to recover to a diameter smaller than that of the well bore to facilitate removal therefrom. The elastomeric material should facilitate sealing of the well bore, casing, or pipe in the inflated state.
“Elastomer” as used herein is a generic term for substances emulating natural rubber in that they stretch under tension, have a high tensile strength, retract rapidly, and substantially recover their original dimensions. The term includes natural and man-made elastomers, and the elastomer may be a thermoplastic elastomer or a non-thermoplastic elastomer. The term includes blends (physical mixtures) of elastomers, as well as copolymers, terpolymers, and multi-polymers. Examples include ethylene-propylene-diene polymer (EPDM), various nitrile rubbers which are copolymers of butadiene and acrylonitrile such as Buna-N (also known as standard nitrile and NBR). By varying the acrylonitrile content, elastomers with improved oil/fuel swell or with improved low-temperature performance can be achieved. Specialty versions of carboxylated high-acrylonitrile butadiene copolymers (XNBR) provide improved abrasion resistance, and hydrogenated versions of these copolymers (HNBR) provide improve chemical and ozone resistance elastomers. Carboxylated HNBR is also known. Other useful rubbers include polyvinylchloride-nitrile butadiene (PVC-NBR) blends, chlorinated polyethylene (CM), chlorinated sulfonate polyethylene (CSM), aliphatic polyesters with chlorinated side chains such as epichlorohydrin homopolymer (CO), epichlorohydrin copolymer (ECO), and epichlorohydrin terpolymer (GECO), polyacrylate rubbers such as ethylene-acrylate copolymer (ACM), ethylene-acrylate terpolymers (AEM), EPR, elastomers of ethylene and propylene, sometimes with a third monomer, such as ethylene-propylene copolymer (EPM), ethylene vinyl acetate copolymers (EVM), fluorocarbon polymers (FKM), copolymers of poly(vinylidene fluoride) and hexafluoropropylene (VF2/HFP), terpolymers of poly(vinylidene fluoride), hexafluoropropylene, and tetrafluoroethylene (VF2/HFP/TFE), terpolymers of poly(vinylidene fluoride), polyvinyl methyl ether and tetrafluoroethylene (VF2/PVME/TFE), terpolymers of poly(vinylidene fluoride), hexafluoropropylene, and tetrafluoroethylene (VF2/HPF/TFE), terpolymers of poly(vinylidene fluoride), tetrafluoroethylene, and propylene (VF2/TFE/P), perfluoroelastomers such as tetrafluoroethylene perfluoroelastomers (FFKM), highly fluorinated elastomers (FEPM), butadiene rubber (BR), polychloroprene rubber (CR), polyisoprene rubber (IR), . . . (IM), polynorbornenes, polysulfide rubbers (OT and EOT), polyurethanes (AU) and (EU), silicone rubbers (MQ), vinyl silicone rubbers (VMQ), fluoromethyl silicone rubber (FMQ), fluorovinyl silicone rubbers (FVMQ), phenylmethyl silicone rubbers (PMQ), styrene-butadiene rubbers (SBR), copolymers of isobutylene and isoprene known as butyl rubbers (IIR), brominated copolymers of isobutylene and isoprene (BIIR) and chlorinated copolymers of isobutylene and isoprene (CIIR).
The expandable portions of the packers of the invention may include continuous strands of polymeric fibers cured within the matrix of the integral composite body comprising elastomeric members 2 and 6 . Strands of polymeric fibers may be bundled along a longitudinal axis of the expandable packer body parallel to longitudinal cuts in a laminar interior portion of the expandable body. This can facilitate expansion of the expandable portion of the composite body yet provide sufficient strength to prevent catastrophic failure of the expandable packer upon complete expansion.
The expandable portions of the packers of the invention may also contain a plurality of overlapping reinforcement members. These members may be constructed from any suitable material, for example high strength alloys, fiber-reinforced polymers and/or elastomers, nanofiber, nanoparticle, and nanotube reinforced polymers and/or elastomers, or the like, all in a manner known and disclosed in U.S. patent application Ser. No. 11/093,390, filed on Mar. 30, 2005, entitled “Improved Inflatable Packers”, the entirety of which is incorporated by reference herein.
FIG. 2 is a schematic cross sectional view along 2 - 2 of FIG. 1 of a portion of the packer illustrated in FIG. 1 . Fibrous layer 3 and cable layer 4 are illustrated in non-expanded state. Also illustrate is a portion of mechanical support structure 5 . Inner elastomeric member 2 and outer sealing member 6 are not shown. Fibrous layer 3 is positioned between cable layer 4 and inner elastomeric member 2 . In certain embodiments the fibers making up fibrous layer 3 may form a unidirectional layer that has the same or different direction as the cables in cable layer 4 . All the fibers may be positioned side by side, with no crossing. More than one unidirectional fibrous layer may be employed, as further discussed in relation to FIG. 4 .
FIG. 3 is a schematic cross sectional view of a portion of the expandable packer of FIG. 1 illustrating how an anti-extrusion layer in accordance with the invention acts during expansion to limit tensile stress on a fibrous layer 3 of the anti-extrusion layer. When the inner elastomeric member 2 of packers of the invention are expanded, gaps may appear between portions of the mechanical structure 5 supporting the outer sealing member 6 (not shown). The cables in cable layer 4 are pushed against mechanical structure 5 by inflation pressure, which creates a force 7 transverse of the longitudinal axis of the packer, held by cable layer 4 . Fibrous layer 3 is pushed against cable layer 4 by inflation pressure 7 . As the cables in cable layer 4 form a homogeneous layer, with no or very few windows or gaps, the fibers in fibrous layer 3 are stressed in transverse compression and see little or no tearing and no tensile stress. The stress on fibrous layer 3 is much lower than if there were no cable layer 4 , and the expandable packers of the invention can resist much higher inflation pressure.
FIG. 4 is a perspective view, with portions broken away, of an expandable packer of the invention illustrating different orientation of two fibrous layers 3 A and 3 B, according to one embodiment of the invention. The fibrous layers may comprise polymeric fibers, or any fiber known in the art that is sufficiently flexible for use in an expandable packer. When multiple fibrous layers 3 are employed, and the fibers making up the different layers may be oriented differently; for example, first fibrous layer 3 A may be set helicoidally, making an angle of with the longitudinal axis of the packer, for example ranging from about 1° to about 20°, while other layers may be substantially parallel to the longitudinal axis of the packer. Second fibrous layer 3 B may be positioned on the first one, with a different angle. For example, this angle may range from −1° to about −20°. In certain embodiments, it may be useful to have additional fibrous layers 3 with each layer having a specific angle.
Expandable packers of the invention may be constructed of a composite or a plurality of composites so as to provide flexibility in the packer. The expandable portions of the inventive packers may be constructed out of an appropriate composite matrix material, with other portions constructed of a composite sufficient for use in a well bore, but not necessarily requiring flexibility. The composite is formed and laid by conventional means known in the art of composite fabrication. The composite can be constructed of a matrix or binder that surrounds a cluster of polymeric fibers. The matrix can comprise a thermosetting plastic polymer which hardens after fabrication resulting from heat. Other matrices are ceramic, carbon, and metals, but the invention is not so limited to those resins. The matrix can be made from materials with a very low flexural modulus close to rubber or higher, as required for well conditions. The composite body may have a much lower stiffness than that of a metallic body, yet provide strength and wear impervious to corrosive or damaging well conditions. The composite packer body may be designed to be changeable with respect to the type of composite, dimensions, number of cable and fibrous layers, and shapes for differing down hole environments.
To use, the expandable packer is inserted into a well bore by conventional means (for example on a tubular string) adjacent to the area to be sealed. The packer is expanded by fluidic or other means until the desired seal is affected. If desired to be removed, the fluidic or other means are disengaged so at to allow the packer to recover a diameter smaller than that of the well bore to facilitate removal therefrom.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will 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. | Expandable packers and methods of using same are described. The expandable packers include an anti-extrusion layer comprising a fibrous layer having a first surface adjacent an outer surface of an inner expandable elastomeric member, and a cable layer adjacent the fibrous layer, the cable layer comprising a plurality of stacked unidirectional layers of cables. The cable layer is adapted to form a barrier substantially devoid of gaps through which the inner elastomer member would otherwise extrude into upon expansion of the inner elastomeric member. This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b). | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT international application Ser. No. PCT/JP2005/007407 filed Apr. 18, 2005 which designates the United States, incorporated herein by reference, and which claims the benefit of priority from Japanese Patent Application No. 2004-139892, filed May 10, 2004, incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a body-insertable apparatus, such as a swallowable capsule endoscope, which is insertable inside a subject and generates a transmission carrier wave when transmitting image information by radio from inside the subject.
[0004] 2. Description of the Related Art
[0005] In a field of microscope, some capsule endoscopes come to be equipped with an imaging function and a radio function in recent years. The capsule endoscope is swallowed by a patient, i.e., a subject, for an observation (examination), travels inside organs (body cavities) such as a stomach and small intestine of the subject following peristaltic movements, and is naturally discharged from a living body of the subject (human body). During an observation period, i.e., a time period after the swallowing up to the discharging, the capsule endoscope sequentially images inside the subject using the imaging function thereof.
[0006] During the observation period, i.e., while the capsule endoscope travels inside the organs, image data obtained inside the body cavity by the capsule endoscope is sequentially transmitted by the radio function, e.g., by radio transmission, to an external device arranged outside the subject, and stored in a memory of the external device. When the patient carries the external device having such radio function and memory function, the patient can freely move without inconvenience after swallowing the capsule endoscope until discharging the same. When the observation by the endoscope is completed, a doctor or a nurse can display the image inside the body cavity on a display unit such as a monitor based on the image data stored in the memory of the external device and make diagnosis.
[0007] One type of the above-described capsule endoscope is described in Japanese Patent Laid-Open No. 2002-345743, for example. The swallowable capsule endoscope of Patent Document 1 incorporates a battery for power supply. An LED generates an illumination light by electricity supplied from the battery. The illumination light is directed to and reflected by a region inside the subject. An imaging element picks up the reflected light, i.e., a reflected image, and obtains image information. Thus obtained image information is transmitted by radio by a transmitting circuit.
SUMMARY OF THE INVENTION
[0008] A body-insertable apparatus according to one aspect of the present invention is inserted into a subject and obtains information of an inside of the subject, and includes an illuminating unit that outputs an illumination light to illuminate the inside of the subject; an imaging unit that obtains image information of the inside of the subject which is illuminated by the illuminating unit; a radio transmitting unit that transmits information of the inside of the subject by radio; a clock generating unit that generates a clock for obtainment of the image information by the imaging unit; and a correcting unit that corrects a clock for radio transmission by the radio transmitting unit based on the clock generated by the clock generating unit.
[0009] The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic diagram of an overall structure of a wireless intra-subject information obtaining system including a body-insertable apparatus according to a first embodiment;
[0011] FIG. 2 is a block diagram of an internal structure of a receiving device according to the first embodiment shown in FIG. 1 ;
[0012] FIG. 3 is a block diagram of an internal structure of a capsule endoscope according to the first embodiment shown in FIG. 1 ;
[0013] FIG. 4 is a block diagram of a structure of an imaging timing system shown in FIG. 3 ;
[0014] FIG. 5 is a timing chart illustrating an operation of the imaging timing system shown in FIG. 4 ; and
[0015] FIG. 6 is a diagram illustrating a conventionally observed fluctuation in a frequency of a transmission carrier wave.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Exemplary embodiments of a body-insertable apparatus according to the present invention will be described in detail below with reference to FIGS. 1 to 5 . It should be noted, however, that the present invention is not limited by the embodiments, and various modification can be made without departing from a scope of the present invention.
[0017] FIG. 1 is a schematic diagram of an overall structure of a wireless intra-subject information obtaining system including a body-insertable apparatus of a first embodiment. In a following description of the wireless intra-subject information obtaining system, a capsule endoscope will be described as an example of the body-insertable apparatus. In FIG. 1 , the wireless intra-subject information obtaining system includes a receiving device 3 which has a radio receiving function, and a capsule endoscope (body-insertable apparatus) 2 which is insertable inside a subject 1 , images inside a body cavity, and transmits data such as video signals to the receiving device 3 . Further, the wireless intra-subject information obtaining system includes a display device 4 which displays an image inside the body cavity based on the video signals received by the receiving device 3 , and a portable recording medium 5 which serves for data delivery between the receiving device 3 and the display device 4 . The receiving device 3 includes a receiving jacket 31 which is worn by the subject 1 and an external device 32 which processes received radio signals, for example.
[0018] The display device 4 serves to display the image inside the body cavity obtained by the capsule endoscope 2 . The display device 4 has a structure like a workstation and displays an image based on data obtained from the portable recording medium 5 . Specifically, the display device 4 may directly display an image like a CRT display, or a liquid crystal display. Alternatively, the display device 4 may output an image on other media, like a printer.
[0019] The portable recording medium 5 can be detachably attached to the external device 32 and the display device 4 . When the portable recording medium 5 is attached to one of the external device 32 and the display device 4 , information can be output from or recorded in the portable recording medium 5 . In the first embodiment, while the capsule endoscope 2 travels inside the body cavity of the subject 1 , the portable recording medium 5 is attached to the external device 32 and records data transmitted from the capsule endoscope 2 . After the capsule endoscope 2 is discharged from the subject 1 , i.e., after the imaging inside the subject 1 is completed, the portable recording medium 5 is removed from the external device 32 and attached to the display device 4 . Then, the display device 4 reads out the data recorded in the portable recording medium 5 . When the data delivery between the external device 32 and the display device 4 is carried out with the portable recording medium 5 such as a Compact Flash (registered trademark) memory, the subject 1 can move more freely during the imaging, compared with a time when the external device 32 and the display device 4 are directly connected by a cable. In the first embodiment, the portable recording medium 5 is employed for the data delivery between the external device 32 and the display device 4 . The present invention, however, is not limited thereto. For example, another type of recording unit, such as a hard disc may be incorporated in the external device 32 , and the external device 32 and the display device 4 may be connected by a cable or by radio for data delivery.
[0020] A structure of the receiving device will be described below with reference to a block diagram of FIG. 2 . The receiving device 3 has a function of receiving the image data of inside the body cavity transmitted by radio from the capsule endoscope 2 . As shown in FIG. 2 , the receiving device 3 includes the receiving jacket 31 and the external device 32 . The receiving jacket 31 is formed so that the subject 1 can wear the jacket 31 , and provided with receiving antennae A 1 to An. The external device 32 processes radio signals, for example, received by the receiving jacket 31 . Here, the receiving antennae A 1 to An may be directly attached to an outer surface of the subject 1 , rather than attached to the receiving jacket 31 . Alternatively, the receiving antennae A 1 to An may be detachably attached to the receiving jacket 31 .
[0021] The external device 32 includes an RF receiving unit 33 , an image processing unit 34 , a storage unit 35 , and processes the radio signals sent from the capsule endoscope 2 . The RF receiving unit 33 performs a predetermined signal processing such as demodulation on the radio signals received by the receiving antennae A 1 to An, and extracts image data obtained by the capsule endoscope 2 from the radio signals. The image processing unit 34 performs necessary image processing on the extracted image data. The storage unit 35 serves to store the image data after the image processing. In the first embodiment, the image data is stored in the portable recording medium 5 via the storage unit 35 . The external device 32 further includes a power supply unit 38 which is provided with a predetermined capacitor or an AC power adapter. Each of the elements in the external device 32 uses electricity supplied from the power supply unit 38 as driving energy.
[0022] A structure of the capsule endoscope will be described with reference to a block diagram of FIG. 3 . The capsule endoscope 2 includes, as shown in the block diagram of FIG. 3 , a light emitting diode (LED) 20 , an LED driving circuit 21 , a charge coupled device (CCD) 23 , a CCD driving circuit 24 , a signal processing circuit 25 , and an imaging timing generating circuit 26 . The LED 20 serves as an illuminating unit that irradiates an examined region inside the body cavity of the subject 1 with light. The LED driving circuit 21 controls a driven state of the LED 20 . The CCD 23 serves as an imaging unit that picks up reflected light from the region illuminated by the LED 20 as an image inside the body cavity. The CCD driving circuit 24 controls a driven state of the CCD 23 . The signal processing circuit 25 processes an image output from the CCD 23 into image information of a desired form. The imaging timing generating circuit 26 serves as a clock generating unit that outputs a reference clock to set a driving timing such as a lighting timing of the LED 20 and an imaging timing of the CCD 23 . The capsule endoscope 2 further includes an RF transmitting unit 27 and a transmitting antenna-unit 28 . The RF transmitting unit 27 modulates the picked up image signal into an RF signal. The transmitting antenna unit 28 serves as a radio transmitting unit that transmits the RF signal output from the RF transmitting unit 27 by radio. Further, the capsule endoscope 2 includes a system control circuit 29 that controls operations of the LED driving circuit 21 , the CCD driving circuit 24 , and the RF transmitting unit 27 . The CCD 23 , the CCD driving circuit 24 , the signal processing circuit 25 , and the imaging timing generating circuit 26 are collectively referred to as an imager 22 . The capsule endoscope 2 having the above elements operates so as to obtain the image information of the examined region illuminated by the LED 20 by the CCD 23 based on the reference clock which sets a desired imaging timing, while the capsule endoscope 2 is inside the subject 1 . The obtained image information is processes by the signal processing circuit 25 based on the reference clock, and converted into the RF signal by the RF transmitting unit 27 , and sent outside the subject 1 by the transmitting antenna unit 28 .
[0023] The imaging timing generating circuit 26 incorporates a circuit (not shown) that generates a reference clock, and outputs the reference clock to the LED driving circuit 21 , the CCD driving circuit 24 , and the signal processing circuit 25 to set the driving timing. Further, the imaging timing generating circuit 26 includes an RF clock frequency dividing circuit 26 a as a frequency dividing unit that divides the frequency of the reference clock, and outputs a frequency-divided clock from the RF clock frequency dividing circuit 26 a to the RF transmitting unit 27 . The reference clock output from the imaging timing generating circuit 26 is produced with high accuracy so as to function as a reference for a minute timing of a driving signal for imaging elements, and an absolute value of tolerance for frequency fluctuation is set small. In the first embodiment, the frequency of the highly accurate reference clock which sets the imaging timing of the CCD is divided by the RF clock frequency dividing circuit 26 a to output an RF clock. Thus, the RF clock for phase synchronization of an RF reference clock is generated. The generated RF clock is output to the RF transmitting unit 27 . Thus, the transmission carrier wave can be stably oscillated. Therefore, a separate installment of a highly accurate clock unit inside the RF transmitting unit is not necessary.
[0024] Further, after the image signal is output from the CCD 23 , the signal processing unit 25 a of the signal processing circuit 25 carries out a desired signal processing on the image signal. Then, the resulting signal is converted into a digital signal by an A/D conversion in the A/D converter 25 b . Further, the resulting digital signal is converted into a serial signal by a parallel/serial conversion in the P/S converter 25 c . Then the resulting serial signal is encoded in the encoder 25 d and supplied to the RF transmitting unit 27 .
[0025] The RF transmitting unit 27 has a PLL circuit 27 a which serves as a synchronizing unit that takes in a frequency-divided clock supplied from the RF clock frequency dividing circuit 26 a . Specifically, as shown in FIG. 5 , for example, the RF clock frequency dividing circuit 26 a outputs an RF clock which is obtained by dividing the frequency of the reference clock for imaging by four, and the PLL circuit 27 a carries out a phase locking based on the RF clock, so that a phase of the RF reference clock is synchronized with the phase of the RF clock at a rising (or a falling) of the RF clock, thereby oscillating the transmission carrier wave in a stable manner and suppressing the fluctuation in the transmission frequency. Thereafter, the radio transmission of the image information is carried out.
[0026] As described above, in the first embodiment, the imager outputs the RF clock with accurate and stable frequency to the RF transmitting unit, and the phase of the RF reference clock is synchronized with the phase of the RF clock. Thus, the RF reference clock can be oscillated in a stable manner and the fluctuation in the transmission frequency of the transmission carrier wave can be suppressed. Therefore, the passing band of the bandpass filter on the side of the receiving device can be set to a narrow band. Thus, the receiving device can receive image information with little noise and with good sensitivity.
[0027] Further, in the first embodiment, a clock is generated by frequency division of the imaging reference clock which sets the imaging timing of the CCD. The generated clock is output to the RF transmitting unit for the correction of the RF reference clock. Therefore, an amount of output electric current of an output pin of an integrated circuit (IC) that forms a part of the imager 22 can be made small, and power consumption for clock output can also be reduced.
[0028] In the first embodiment, during the driving timing of the CCD, for example, the output of the RF clock from the frequency dividing circuit may be stopped, and the driven state of the CCD may be notified to the RF transmitting unit 27 by enable signals. In response to the operation of the imaging timing generating circuit 26 , the RF transmitting unit can stop the driving. Thus, the power consumption of the overall system can be reduced. In addition, if the output of the RF clock is stopped while there is no input of the image signals and there is no need of driving of the RF transmitting unit 27 , the power consumption can be further reduced. Still further, to allow for the synchronization of the RF clock and the RF reference clock, the RF clock frequency dividing circuit can be set so that the RF clock has a higher frequency than a transmission frequency of one pixel of the CCD. Still alternatively, the RF reference clock of a high frequency band may directly be generated by frequency dividing, and supplied to the RF transmitting unit.
[0029] 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. | A body-insertable apparatus is inserted into a subject and obtains information of an inside of the subject. The body-insertable apparatus includes an illuminating unit that outputs an illumination light to illuminate the inside of the subject; an imaging unit that obtains image information of the inside of the subject which is illuminated by the illuminating unit; a radio transmitting unit that transmits information of the inside of the subject by radio; a clock generating unit that generates a clock for obtainment of the image information by the imaging unit; and a correcting unit that corrects a clock for radio transmission by the radio transmitting unit based on the clock generated by the clock generating unit. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a device for an automatic interchange of grippers to robots or manipulating devices.
Devices for coupling grippers to robots or manipulating devices of the aforementioned type generally include a mounting or receiving body or member, and an interchanging plate carrying a gripper removably-connectable to the mounting body.
A complete automation during the manufacture and assembling of articles of manufacture has, until now, only been possible in mass production. Various article or workpiece dimensions or their differing geometries have required an exchange of grippers or gripper jaws carrying the tools.
A fully automatic programmable tool exchange or tool plate exchange has been known in machine tools or treatment centers.
It has not been possible to provide an automatic and programmable gripper exchange in the field of robot technology without overcoming considerable difficulties requiring complex solutions.
An automatic manufacturing operation for producing a limited number of a line of products has been possible only when the machine tool and the manipulating device or robot were adjusted to a new workpiece corresponding to a new line of products to be manufactured.
A gripper-interchange system has been known, in which receiving or engaging forces of the interchanging plate are generated by electromagnets mounted in the receiving body. Although the principle of operation of this system is very simple, the system has substantial disadvantages. During the manufacture of iron-containing articles or, in the case of iron-containing chips, this system cannot be employed because there is a danger of contamination of this system. In case of power failure the interchanging plate can suddenly drop. The entire weight of the system in comparison with its holding force is large.
Another known device of this type operates with compressed air and included laterally extended pressure air cylinders which effect locking of the interchanging plate carrying the gripper to the mounting plate connected to a robot. A bulky, heavy and complex intermediate member for receiving an also complicated gripper-receiving or interchanging plate is arranged between these two cylinders. The heavy weight of this conventional device substantially limits the abilities of the device to receive heavy workpieces. If rather heavy articles are to be produced another adjacent large robot must be employed to treat the articles. Dimensions of this device, however, considerably limit its application. Furthermore, since the conventional device requires special treatment procedures during its manufacturing, it has been very costly. In addition, an extremely costly interchanging plate is required for each gripper.
Yet another known device for coupling the gripper-holding interchanging plate with a mounting or receiving body includes a short or steep cone with tension belts pulled into another cone. This device has been known in the field of machine tools, and, more particularly, in milling machines. The coupling and locking of the gripper-holding plate with the mounting body, and therefore a safety, are ensured even in the case of power failure. With milling machines, a sufficient space is available along the machine so that the weight of the pulling motor does not present any disturbance. However, because of its limited volume, this system is not suitable for application in industrial robots. The weight of this system reduces a possible weight of workpieces being treated, and the overall length of the system requires a specific robot head. In as much as a special robot head must be provided with an electric motor or compressed air motor, the system has not been and could not be universally utilized.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device for an automatic interchange and coupling of grippers on robots or manipulation devices of the type having a mounting body and a removably-detachable interchanging plate holding the gripper.
It is another object of the present invention to provide an automatic gripper-interchanging and coupling device which can be universally utilizable and can be employed practically with all robots and manipulating apparatus.
Yet another object of this invention resides in the providing of a coupling device which eliminates any danger of the falling of a gripper or the disconnection of the interchanging plate holding the gripper from the mounting body in case of a power failure.
A further object of this invention is to provide a gripper interchanging device which has a reduced weight, smaller dimensions, and simpler construction as compared to those of conventional gripper-interchanging and coupling arrangements.
These and other objects of the present invention are attained by a device for an automatic interchanging and coupling of grippers on robots or manipulating devices, comprising a mounting body connectable to a robot; a gripper-holder interchanging plate removably-connectable to the mounting body; and coupling means for coupling said interchanging plate to the mounting body and including a piston movable in the mounting body along an axis thereof, an actuation cone mounted to the piston, and adjustable locking elements cooperating with the cone and aligning and locking the interchanging plate with the mounting body in a form-and/or force locking fashion.
The present invention offers an automatic gripper-interchanging system which is universally utilizable and therefore can be employed practically in all industrial robots and manipulating devices. The device according to the present invention is very compact, is light weight and is inexpensive. Furthermore, an integral energy supply to, for example, the grippers, is provided within the construction and can be automatically separated. Furthermore, the device can have various control functions provided by, for example, plugs, strips, approximation switches or the like. It is specifically advantageous that, in the case of power failure, the interchanging plate with the gripper can not fall but is held in its assembled position by the locking elements in the form-and/or force-locking manner. Therefore, the proposed construction enables a reliable, safe and automatic interchange of grippers on the robots or similar manipulating devices, with a precise alignment of the elements to be coupled.
The piston may be cylindrical and have a piston rod, with the piston rod being formed in one piece with the actuation cone.
The interchanging plate may be formed with recesses, with the locking elements, upon the movement of said piston being radially outwardly pressed by the cone into the recesses to thereby couple the interchanging plate to the mounting body.
The locking elements may be pins, balls or pins having conical tips engageable in the recesses of the interchanging plate.
The actuation cone, upon a simple axial mutual displacement of the mounting body and the interchanging plate, snappingly pushes the locking balls or pins into the respective recesses of the interchanging plate, which is important for an automatic interchange of these structural components.
The piston is loadable with pressure of a pressurized medium at two sides thereof, and its movement path along the axis of the mounting body may be adjustable by said pressure.
The device may further include a spring which continually urges said actuation cone in a coupling position, so that in the case of power failure the parts remain held with each other in the coupled position not only by a form-locking and force-locking connection but also by means of the force of said spring.
The locking elements are displaceable against a force of said spring and tend to move to the coupling position.
The piston and the actuation cone may be formed in one piece and they both are formed axially symmetrical. Such a construction is particularly advantageous and inexpensive for turning machine tools.
The cylindrical piston with its piston rod and said actuation cone may be a one-piece hollow member which has one open side, with the spring being a compression spring which extends in the member and is supported at one end thereof against the mounting body and at another end thereof against a closed side of the member which forms said actuation cone. This embodiment is particularly space-saving and allows for a significant reduction in weight of the device. Further, a space for accommodating the spring is available within the hollow piston.
The mounting body may include an axially spring-biased centering cone engageable in a centering recess provided in the interchanging plate. The centering cone provides for a precise radial alignment of the interchanging plate with the mounting body.
The mounting body may be formed in one-piece with another centering cone, and the interchanging plate is formed with a recess conforming to the another centering cone and engages the latter is assembly.
The device may further include a number of proximity switches which inform a user of whether the interchanging plate is coupled to the mounting body, and whether a suitable interchanging plate is coupled to the mounting body in a correct position. For example, three proximity switches can offer six code combinations to determine an automatic correspondence of the interchanging plate to the mounting body.
The device may further include an electric plug mounted to the mounting body and at least one coupling element connectable to the plug for transmitting electrical signals. Thereby it can be determined, for example, whether or not a workpiece is engaged by the gripper or whether or not the gripper fingers lie correctly on a workpiece.
The locking element may be formed by an elastic ring, formed, for example, of an elastomer.
The interchanging plate may be provided with opposing side grooves for supporting in a predetermined position of a magazine plate.
The device may further include a self-sealing elastic sleeve mounted in a region between the mounting body and the interchanging plate for passing the pressurized medium therethrough.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is an axial partial cross-sectional view of a first embodiment of a device for an automatic interchange and coupling of grippers on robots or manipulating devices;
FIG. 1B is an axial partial cross-sectional view of another embodiment of a device for automatic interchange and coupling of grippers on robots or manipulating devices;
FIG. 2 is an exploded partial cross-sectional view of a detail of a portion of the device for an automatic interchange and coupling of grippers constructed in accordance with the present invention;
FIG. 3 is a partial cross-sectional view of a further modification of a detail for the device constructed in accordance with the present invention;
FIG. 4 is a partial cross-sectional view of yet a further embodiment of the present invention;
FIG. 5 is a partial cross-sectional view of a still further embodiment of the present invention;
FIG. 6 is a top plan view of a gripper associated with an interchanging plate in accordance with yet another embodiment of the present invention;
FIG. 7 is a partial cross-sectional view of the embodiment of FIG. 6; and
FIG. 8 is a side view of the emboidment illustrated in FIGS. 6 and 7.
DETAILED DESCRIPTION
Referring now to the drawings wherein like reference numerals are used throughout the various views to designate like parts and, more particularly, to FIGS. 1 and 2, according to these figures, a gripper 1 is provided with a plurality of gripping fingers 2, with the gripper 1 being releasably attached by a plurality of circumferentially distributed screws 3, only one of which is shown in the drawings, to an interchanging plate 4. The interchanging plate 4 is, in turn, automatically releasably connectable with a mounting of receiving body 5 in a conventional manner.
A pressure medium supply, for example, pressurized air, is supplied to the gripper 1 through a conduit (not shown) by way of a connection opening 6 and passages 7, 8 and 9 which are in communication with each other. Sealing means 10, 11, 12 such as, for example, O-rings are provided for ensuring that the structural components are pressure-air tight sealed from each other. A sleeve 13 made, for example, of a suitable synthetic plastic material or elastomer is elastically supported at a rear side thereof against a sealing element 14 so that the sleeve 13, at a front side thereof, lies against a planar parallel wall of the interchanging plate 4 surrounding the passage 8.
A cover 15 is threadably inserted into the mounting or receiving body 5, with the cover 15 having a central recess 16 acting as a bearing support for a compression spring 17. The opposite end of the compression spring 17 is supported against an inner end face of an actuation cone which is integrally connected to a piston rod 19 of an axially displaceable cylindrical piston. The piston 20 is longitudinally and sealingly displaced through a sealing element 21 along an inner wall 22 of the cylindrical portion 23 of the cover 15. The piston rod 19 is also longitudinally and sealingly displaceable through a sealing element 24 in a cylinder 25.
As shown in FIGS. 1A, 1B and 2, a centering cone 26 is integrally formed into one piece with the mounting body 5, with the centering cone 26 including a plurality of recesses or openings 27 circumferentially distributed on the centering cone 26. These openings 27 engage therein locking members or elements of the device. As shown in FIG. 1B, a locking element may be in the form of a ball 28 while, as shown in FIG. 1A, the locking element may be in the form of a pin 29 with a conical tip. It is to be understood that either the ball 28 or the conical locking element 29 can be employed in the same unit.
The locking elements 28, 29 are supported against a beveled outer surface of the actuation cone 18 and are pressed by this surface through openings 27 into locking recesses 30 or 31 provided in the interchanging plate 4 and have surfaces which conform to the engaging surfaces of the locking elements 28, 29. Thereby, the locking elements 28, 29 provide for a form-locking and force-locking fastening of the receiving body 5 with the interchanging plate 4.
The mounting or receiving body 5 of the embodiments of FIGS. 1A, 1B has a further connection opening 32 for connection with a pressure-medium conduit (not shown), for example, a pressure-air conduit. The connection opening 32 is in communication through a passage 33 formed in the mounting body 5 with a cylindrical chamber 34 so that, upon loading of the device with the pressure medium, the piston 20 is pressed in the direction of arrow Y, and thereby the locking elements 28 or 29 are pushed to the locking position, provided with the supporting action of the compression spring 17. If energy or power supply fails the interchanging plate 4 with gripper 1 does not fall off because the locking elements 28 or 29, supported by the compression spring 17, provide for a reliable coupling.
Upon loading of a cylindrical chamber 35, positioned opposite to the cylindrical chamber 34, through a passage 36, a piston 20 can move in the direction of arrow X and the interchanging plate 4 and gripper 1 will be uncoupled from the receiving body 5.
In FIG. 2, a centering or aligning conical member 37 is axially displaceable against the restoring force of a spring 38 positioned in the receiving or mounting body 5, with the spring 38 being supported against a threaded plug or stopper 39. While an axial alignment of the interchanging plate 4 with the mounting body 5 through the centering cone 26 is carried out, a radial centering is also possible by the centering conical member 37.
As shown in FIG. 2, a coupling 40 is provided for an electrical plug 41. Thereby it can be controlled whether or not the gripping fingers 2 are engaged with a workpiece to be treated.
As shown in FIG. 3, a proximity switch 42 is positioned in a recess provided in a mounting body 5a engageable, by a centering cone 26 thereof, with an interchanging plate 4a. A recess 44 serves for receiving a bolt (not shown) for connecting the mounting body 5a to an arm of a robot or manipulating device.
In the embodiment of FIG. 4, the mounting body 5b is engaged with centering cone 26 in a recess provided in an interchanging plate 4b and matching the shape of the centering cone 26. Thereby, the mounting plate 5b and interchanging plate 4b are axially aligned with respect to each other. The interchanging plate 4b has an annular groove 45, in which an elastic ring 46 is positioned which is supported against a further elastic ring 47 or against individual segments of such ring. Rings 46 and 47 are formed of synthetic rubber plastics. The ring 47 or its segments can be also made of metallic material and have a conical sloped surface 48 which abuts in a form-locking manner against a conical, similarly sloped surface 49 of the annular piston 50. Sealing elements 51 and 52 are inserted at both sides of the annular piston 50. A passage 53 for supplying pressure medium into a cylindrical chamber 54 and a passage 55 for supplying pressure medium into a cylindrical chamber 56 are formed in the mounting body 5. The cylindrical chambers 54 and 56 are alternatingly loaded with the pressure of pressure medium, for example, air, so that the annular piston 50 is displaced either in the direction of the arrow X or in the direction of arrow Y, which results in a respective radial displacement of the ring-shaped element 47 so that ring 46 is either pressed into the annular groove 45 or leaves the latter. Thereby the interchanging plate 4 can be respectively, coupled or uncoupled from the mounting or receiving body 5.
As shown in FIG. 5, two proximity switches 57, 58 may be provided. It is also possible to provide, for example, three proximity switches distributed in the circumferential direction in the mounting body 5c. For example, six codes, which would correspond to the central functions, can be obtained by three proximity switches. A recess 59 is formed in an interchanging plate 4c at the end face thereof abutting against the mounting body 5. At this side, the proximity switch 57 has no contacts. Thereby it can be detected whether the "right" interchanging plate is selected and/or whether this plate is in the "right" position. The proximity switch 58 has "contacts".
In FIGS. 6-8, an interchanging plate 4d is detachably insertable in a magazine plate 60 by grooves 61, 62 for storing purposes. The interchanging plate 4d together with the gripper 1 can be automatically moved from the magazine plate 60. A proximity switch 63 positioned on the plate 60 enables a detection as to whether or not the interchanging plate 4d is inserted into the gripper magazine plate 60 and/or whether the position of plate 4d is correct.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of devices for the automatic exchange and fastening grippers to robots or manipulation apparatus differing from the types described above.
While the invention has been illustrated and described as embodied in a device for the automatic exchange and coupling grippers to robots or manipulation devices, 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 of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A device for an automatic interchange and coupling of grippers on robots or manipulating devices includes a mounting member connectable to a robot and a gripper-holding interchanging plate which is formed with recesses receiving locking balls or pins interpositioned between the interchanging plate and an actuation cone of an axially movable piston positioned in the mounting member. The movement of the piston causes the actuation cone to push the locking balls or pins to move radially outwardly into the recesses of the interchanging plate to lock the latter with the mounting member. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the priority date of Feb. 22, 2007, which is the filing date of Provisional Application Ser. No. 60/891,113 filed by the present inventive entity.
TECHNICAL FIELD OF THE INVENTION
This invention relates to the general field of building and structure sciences and the particular fields related to the underlying technologies of building structures and mechanical systems used to design, construct and maintain buildings and building environmental systems, including Heating, Ventilation and Air Conditioning (HVAC) practices. The intention of such technologies and practices is to design and/or retrofit buildings so that they can be kept in a good state and to enhance building performance such that occupant comfort and health are maintained at an acceptable level and the building has an acceptable service life.
BACKGROUND OF THE INVENTION
Research into the effects of uncontrolled moisture, including moisture in the form of high humidity levels has clearly demonstrated that exposure to high humidity levels leads to a variety of building related problems. Relevant background material on moisture effects and control is included in the references identified in and incorporated by reference into this disclosure. The extent of the resulting damage will be related to many factors, however as a general principle, increasing amounts of moisture distributed in expanding areas for increasing amounts of time will all (individually and in combination) result in a corresponding increase in the negative impacts on the building. There is a very clear relationship between moisture management problems and mold contamination problems in buildings.
The range of negative impacts is large, however some examples include:
1. Cosmetic and structural damage caused by staining, corrosion, dimensional changes due to moisture content changes in materials and microbial growth such as fungi, including mold and wood decaying fungi.
2. Damage to other building systems such as corrosion of electrical components and mold growth on duct and pipe insulation.
3. Increased building operating costs due to excessive moisture removal loads on cooling or dehumidification equipment, make-up air systems or other building services.
4. Loss of use of buildings or areas of buildings. In the case of homes, schools, health care facilities and other buildings, the loss of use may have significant impacts on many aspects of the occupants and the ability to provide for basic needs.
5. Increased custodial and maintenance requirements to maintain and remediate the effects of moisture problems.
6. Reduction in the value of the building as an asset due to the inherent liabilities associated with moisture and/or mold problems.
7. A diverse range of adverse health affects have been attributed to the exposure of occupants to damp and/or moldy buildings.
These basic concepts and concerns form the focal point of many documents related to investigating moisture management problems in buildings, preventing moisture damage and remediating moisture damage.
Various organizations, including Canadian and United States Federal Government Agencies, have recognized moisture management and mold contamination problems as being significant issues for buildings and building occupants. Regular inspections and prompt responses to problems are a key component of good building management. References related to the general issues of building science, indoor air quality, moisture management and mold related building issues include (the disclosures of which are incorporated herein by reference):
(1) “Mold Remediation in Schools and Commercial Buildings”, US EPA, Washington, D.C., March 2001.
(2) “Health Canada proposes a new guideline on mould in residential indoor air”, Environmental and Workplace Health, Health Canada, Ottawa, ON., Jan. 26, 2007.
(3) “Fungal Contamination in Public Buildings: Health Effects and Investigation Methods”, Health Canada, Ottawa, ON., 2004.
(4) “Clean-Up Procedures for Mold in Houses”, Canada Mortgage and Housing Corporation, Ottawa, ON., Revised 2005.
In the specific area of moisture problems in building crawl space foundations, the following reference paper contains material that can serve as background and supporting information, and this paper is incorporated herein by reference:
Figley, D. A., Sieber, R. “Cleanup of Microbial Contamination in Major Building Crawlspaces”, Proceedings of the 9th International Conference on Indoor Air Quality and Climate, Indoor 2002, Monterey, Calif., Jun. 30-Jul. 5, 2002.
This paper summarizes the experiences obtained from the investigation and remediation of a number of building crawl spaces and identifies the significant problems caused by the lack of moisture control and early detection of major moisture release events. The material and concepts described in this paper form part of this disclosure and are included by reference.
Moisture management is the general art and process of understanding and controlling moisture activity in a building structure. Moisture can be present in many forms including, but not limited to:
(1) vapor or humidity in the air;
(2) water evaporated, absorbed or precipitated through dew or condensation, typically onto surfaces or into structural or building assemblies and volumes including moisture present on or within building components including structural members;
water present as snow, ice, or frost buildup which can melt to produce an uncontrolled source of liquid water; or
(3) water present as an exposed liquid, typically as puddles or that might lie on surfaces as it migrates to a lower level, such as wetted walls, foundations or window surfaces.
Mechanisms that may bring water within a building (or alternately, collect small amounts of water until they form a large source of moisture) are many, including but not limited to:
(1) humidity present in the ventilation air source, typically outdoor air that is drawn into the building and conditioned either intentionally as part of the HVAC makeup air or combustion air or unintentionally as a result of leaks within the building envelope air/vapour barrier assembly;
(2) water introduced by introducing wet articles into the conditioned building envelope such as wet clothing, snow and rain on articles of equipment, vehicles and the like, drying of wet materials such as firewood, etc.;
(3) humidity introduced by occupant activities such as cleaning, washing, clothes drying, cooking, plant watering and bathing;
(4) moisture introduced through unintentional water releases such as plumbing and heating system leaks, sewer backup, vandalism and the like;
(5) moisture introduced through structural or moisture barrier leaks including but not limited to roof and foundation leaks, absent or impaired access hatches or windows or the like that can allow, rain, snow melt, surface or ground water to enter the conditioned spaces of a building; or
frost or ice buildup on cold surfaces exposed to moist air which at some point may thaw and produce unanticipated water sources.
Note, that within this disclosure, “conditioned” refers to air, air volumes and building zones intended to be brought into and maintained within a define or acceptable range of temperatures through the use of HVAC techniques known to the art.
Current best practices for moisture control can include a combination of:
(1) proper building and building envelope design, including material selection
and construction methods;
(2) foundation drainage systems including collection and disposal piping systems;
effective environmental water drainage including building location selection, grading the building surroundings for proper surface runoff of storm water drainage and snow melt, effective snow removal practices and the like;
(3) well conditioned air to ventilate the affected building volumes;
training for occupants and building operators to make them aware of their impact on moisture management and to provide them with practices and policies to reduce moisture problems in buildings;
(4) routine inspection and maintenance of all building areas and systems to allow for detection and repair of moisture management problems; and
(5) detection of water leakage and/or water collection in both occupied and unoccupied areas using sump alarms, floor wetting detectors, water conductivity alarms and the like.
However, in real world practice, it is not always possible to incorporate or design for all possible scenarios or extremes, nor for the occurrence of the myriad possible building system impairments or breakdowns. As well, traditional sump pump alarms and floor wetting detectors can not always detect a leak or water entry point, since for these to function properly, significant amounts of water need to be present at the detection site. Excessive moisture can occur without these systems being activated. Confounding this situation is the effect of occupant lifestyle and in many cases, the lack of continued effective, routine inspections and maintenance.
It should also be noted that many locations in a typical building structure are not easily inspected on a day-to-day basis, so these locations tend to be investigated only when problems show up elsewhere in a building or there are other reasons to suspect a problem condition might be present.
For instance, conditioned crawlspaces under large buildings are difficult to inspect fully, as access is restricted, lighting is typically poor and there are often regions that have poor sight lines from where an inspector can position themselves. Additionally, these crawlspaces are often subdivided into relatively small areas as part of the fire protection and containment design of a building. The crawlspaces are often also where many of the buildings service lines run, such as water and sewer lines which can leak and are also where water from leaks and spills on higher floors migrates.
As a net result, these types of spaces can often have significant moisture problems for extended periods before being discovered. These types of situations are common in unsupervised areas in many buildings structures such as nursing residences, schools, homes residences, public buildings, offices and other such structures. These problems can also be present in occupied portions of buildings if the occupants are not observant or are not trained to recognize conditions indicative of moisture control failures.
Of further concern are buildings or building areas that may not normally be occupied, may not be frequently inspected or may otherwise be out of sight or out of mind for extended periods. These scenarios occur often, for instance with:
(1) buildings not occupied for periods of a day or more, such as churches, meeting halls, homes with vacationing occupants or for sale, business offices that are empty over the weekend and the like;
(2) schools closed for the season or for holidays;
(3) buildings with seasonal occupancy such as cabins, camps and the like; and
(4) buildings not intended to be regularly occupied such as pump houses, utility buildings, storage sheds and warehouses, parking garages and the like.
As a result, many buildings suffer serious damage from moisture control problems that could otherwise be avoided given an appropriate measurement and warning system capable of detecting the moisture problems early.
OBJECTS OF THE INVENTION
It is an object of this invention to monitor the humidity levels in a building or structure and warn of high or unusual humidity conditions that might result in accelerated building deterioration including structural damage, fungal or mold colonization, flood and the resulting health and property issues that result from such occurrences.
It is a further object of this invention to provide alarms to warn the building operator of problematic moisture conditions in any or all of occupied, unoccupied or unsupervised zones within a building envelope.
It is yet another object of this invention to provide the operator utilizing a systems as taught by this invention with an estimate of the magnitude of the moisture problem.
It is yet a further object of this invention to determine the expected levels of moisture in building zones, based upon the characteristics and source of ventilation air and react to unexplained levels of moisture or rates of increase in the moisture content determined at various locations within the building.
It is an object of this invention to expedite the detection and localization of moisture sources such as seepage, water leaks or floods from building systems or that might enter a building from the exterior.
It is another object of this invention to detect both localized and distributed moisture problems resulting from improper ventilation, leakage, seepage, condensation, frost melt, precipitation, flood and the like within an area, volume or zone, without the requirement for direct contact with the water or the wetted surface.
It is a further object of this invention to detect occupancy behavior that may lead to excessively high humidity levels within conditioned air spaces within a building envelope.
It is a further object of this invention to monitor ambient humidity trends so that mitigations and remediations to alleviate high moisture situations can be sought before significant damage to the building (including mold contamination) can occur and before occupant health is negatively impacted.
It is another object of the invention to reduce the cost and severity of building repairs or remediations through the early detection of problematic humidity conditions.
It is yet another object of the invention to suppress false alarms caused by predictable or assessable changes in the moisture content of the air that are due to known causes that are not considered moisture control problems.
It is a further object of the invention to compare moisture levels in monitored areas to the ambient levels, to discriminate between changes due to normal building use patterns and external environmental conditions and changes due to moisture introduced by building system failures such as leaks.
SUMMARY OF THE INVENTION
This invention provides suitable detection and monitoring capability in an automated system thus making it possible to detect the presence of moisture problems when they manifest as abnormal humidity in one or more discrete ventilation zones within a building envelope. The abnormal humidity can then be investigated and resolved or mitigated well before building damage or adverse occupant health effects occur. The present invention provides an early warning system that will alert personnel prior to the occurrence of a moisture problem.
In general, the invention is embodied in a method wherein the moisture contents within various air volumes around and within a building environmental envelope are monitored and alarms are generated when site configurable combinations of moisture conditions and moisture trends are inconsistent with proper building operation and performance.
As used herein, the term “proper building operation and performance” means enabling the building to perform consistent with it's intended use and for it's intended lifetime, by assisting in maintaining the building in a state wherein the moisture conditions are conducive to occupant health and comfort as determined by appropriate Health and Building Code requirements or other accepted engineering and operating standards, such as ASHRE, while the integrity of the building structure and contents are enhanced or preserved. While ASHRE has been specifically mentioned, it is understood that those skilled in the art will know of other suitable sources of such information.
Furthermore, as used herein, the term “site configurable combinations of moisture conditions” means that a particular installation of a system can be configured and commissioned by a knowledgeable operator who determines what particular combination of preset alarm threshold values and integration time constants are appropriate for the particular installation, based upon engineering principles and site specific knowledge of the particular building and that building's operational requirements as determined by appropriate Health and Building Code requirements or other accepted engineering and operating standards, such as ASHRE, or other recognized sources of such information as will be understood by those skilled in the art
More specifically, the invention is embodied in a method of monitoring the moisture content of air located in a structure comprising: measuring the moisture content in a sample of air at a reference location and using the moisture content in the sample of air from the reference location as a normal value; measuring the moisture content in air located at a selected location within a structure and using the moisture content in the air from the selected location as a sensed value; smoothing the temporal characteristics of the measured values over one or more time frames to reduce the effects of measurement noise and short term moisture transients; relating the smoothed sensed value of moisture content from the selected location to the smoothed normal moisture content from the reference location and defining a differential moisture content; and generating an alarm if the differential moisture content exceeds a preset value. As used herein, the term “preset value” is defined as a value that has been independently determined to be appropriate for the particular building and occupancy situation by knowledgeable practitioners based on experience in similar applications and situations and through the use of engineering principals. Essentially, this is value is based on the body of knowledge available to the person who configures the system.
For instance, water leaks that are relatively small can evaporate in conditioned air spaces before the water manages to collect at a floor wetting detector or sump. However, these leaks can still be large enough to significantly impact the humidity in the zone, with all the attendant problems that creates. With a detection mechanism based on humidity, small volume rate leaks can be detected earlier.
A particular improvement of this invention over prior art is that it takes advantage of the volume mixing and integration capability provided by the ventilation air normally traveling through a building. As the ventilation air passes by a moist surface, it can collect moisture, which it can then carry to a moisture detection and alarm system that resides downstream in the air flow. Thus, even small, localized moisture sources can be detected without the alarm system having to be in direct contact with the leak or the resulting liquid water. In principal, this allows the system to be sensitive to moisture sources anywhere within a particular ventilation zone by sampling the ventilation air stream at a point of confluence, such as just before it exits the affected zone.
This invention should also be clearly differentiated from the many simple humidity monitoring systems that are presently available on a commercial basis. With the presently available systems, the humidity sensors (or their associated alarms) are configured to trigger an alarm once a particular threshold is reached in the area adjacent to the sensor. These simple systems do not modify their alarm behavior as a result of measured environmental changes such as increases in the outdoor humidity levels nor do they self modify to account for the variations in the humidity often resulting from short term occupancy related humidity changes (for example, those produced by the occupants when they shower or do laundry). These presently-available alarms do not provide as accurate and as reliable early warning system which can alert personnel prior to a moisture problem actually developing.
As a consequence of the simple mode of operation, the simple systems typically have their alarm thresholds set to relatively high levels to reduce the number of false alarms and resulting inconvenience to the occupants and building operators. Alternatively, if the alarm thresholds are left low, and many nuisance alarms are produced, the occupants and building operators become conditioned to either ignore the resulting alarms or respond slowly.
These consequences are inherently at odds with the need for early detection of moisture control problems. Desensitizing the alarms to prevent false triggering simultaneously desensitizes the alarms to real problems. In many situations, to accommodate environmental variations and occupant behavior, the alarm thresholds in these systems are set high enough that humidity can exist at levels sufficient to result in building damage, without an associated alarm being triggered.
Alternately, if the systems produce frequent nuisance alarms, the occupants and operators loose trust in the system and fail to respond to alarms accordingly. In contrast, the present invention provides an intelligent, self correcting control mechanism and process wherein the useful sensitivity of the alarm system can remain high so as to detect legitimate moisture control problems early while the frequency of false alarms is dramatically reduced.
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 following claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.
FIG. 1 shows one embodiment of the invention wherein system includes a Control Station, a Reference Sensing Station, and multiple Zone Sensing Stations.
FIG. 2 shows one aspect of the invention wherein the local Relative Humidity and Temperature are measured by the Zone Sensing Stations and conveyed to the Control Station for comparison to measurements retrieved from a Reference Sensing Station.
FIG. 3 shows a conceptual diagram of a simple one storey building with a conditioned crawlspace and one embodiment of the system envisioned deployed within the structure.
FIG. 4 shows a conceptual diagram of a more complex one storey building with multiple occupied areas and crawlspace zones with another embodiment of the system envisioned deployed within the structure.
DETAILED DESCRIPTION OF THE INVENTION
Airborne humidity monitoring provides a direct measurement of the moisture content of the air, effectively the moisture mass that is available to the building environment. In most cases, this measurement will be very responsive to changes caused by a significant moisture source within or adjacent to the building's conditioned envelope.
This invention is based on the psychrometric principles governing the behavior of moisture in air and other materials. Abnormal or undesirable humidity behavior may indicate that a moisture management problem exists. Problems could relate to water leakage, changes in ventilation, dehumidification or air conditioning system performance, building operation or occupancy issues.
The invention described herein utilizes a combination of humidity and temperature monitoring points to assess the prevailing moisture conditions and trends in various conditioned building spaces and zones. Humidity may be optionally measured through absolute or relative means and the measurements may be performed using various methods know within the art based on the psychrometric properties of water in air and building materials. Broadly stated, the invention is embodied in a method wherein the moisture contents within various air volumes around and within a building environmental envelope are monitored and alarms are generated when site configurable combinations of moisture conditions and moisture trends are inconsistent with proper building operation and performance.
Measurements that are able to determine or act as acceptable surrogates for the moisture content in the air and that are applicable over various time scales, may optionally include but are not limited to:
(1) relative humidity or relative humidity corrected to a standard set of conditions to ease comparison;
(2) dew point analysis;
(3) wood moisture content; or
(4) determining the absolute moisture content of the air through gravimetric, calorimetric, thermal conductivity or other means.
This disclosure of the invention makes frequent reference to airborne moisture, humidity or relative humidity, however no limitation of the invention based upon the particular terminology and all forms of airborne moisture are implied. The moisture content in the air may be determined using various sensors and detectors based on conductivity, capacitance, chemical reaction, moisture induced dimensional changes, gravimetric, volumetric, thermally induced spontaneous condensation or other means or through other techniques that are or may become known in the art for determining moisture content of air and materials. It is also noted that the invention will be described in relation to a building and to air entering, leaving or residing in the building; however, this description will be for the sake of convenience and is not intended as a limitation since the early warning aspects of the present invention can be applied to any structure, including, but not limited to, storage facilities, clean rooms, equipment rooms and facilities, power plants, and the like, and any air or other atmospheric gas associated with that structure. Furthermore, the term “wood moisture” is a term well known in the art and thus it will not be discussed in detail. Wood moisture varies relatively slowly over long periods as compared to air and is not as responsive an indicator of a recent exposure to moisture. However, wood is inherently an integrator of the general exposure to environmental moisture and can be used to provide a surrogate measure of the long term humidity levels in a building zone. Within our current invention, the wood moisture is seen as an auxiliary measurement that can be used to confirm or contradict an alarm assessment and provide additional diagnostic information on how the building and alarm system is behaving.
Regular and repeatable air moisture measurements are combined through an algorithm to allow the device to assess if the moisture conditions are within normal and acceptable ranges or alternately might be elevated or rising at an unexpected rate. Certain elevated levels or unexpected rates of rise are indicative of water escape, accidental introduction of high moisture content ventilation air or some other moisture management or moisture control failure as previously discussed. The measurements and subsequent processing effectively analyze the humidity within building environments to assess the potential of a moisture management problem that needs attention.
The decision algorithms are at their core a series of staged go/no-go or pass-fail tests that are applied to the results of the various smoothing calculations. Each of the tracked parameters is compared to a series of thresholds, or pre-set values, or to either one or a mathematical combination of other parameters, or in some cases both thresholds and combinations of other parameters to determine if an alarm condition exists.
For example, a simple test could be written as:
IF {parameter_value x >threshold x } THEN activate alarm x ;
A practical example of this simple alarm could be:
IF {Standardized_Reference_Humidity>60%} THEN Go_Humidity_Alarm;
A more complicated example might be:
IF {(parameter_value x −parameter value y )>threshold x,y } THEN activate alarm x,y ;
A practical example of this more complicated alarm could be:
IF {(Standardized Station 1 RH−Standardized Reference Station RH)>5%} THEN Go_High_Difference_Alarm;
The overall decision algorithm is a series of such logical tests that are reevaluated on each scan cycle and which might generate zero, one or many alarm conditions.
For many situations of interest, there are three primary conditions that may indicate that a moisture management problem is present. These are, in no particular order:
1) Interior humidity levels exceed values expected based on outdoor, ambient or indoor reference air conditions and normal building use.
2) Indoor humidity levels are increasing at a rate that exceeds the expected change based on outdoor, ambient or indoor reference air conditions and normal building use.
3) Indoor humidity levels exceed a threshold where moisture damage or building deterioration can occur, regardless of the moisture source.
Other important conditions or criteria may also exist for specific building situations.
These primary conditions can be extended to a decision algorithm to implement a series of specific alarms. For example, the instrument may determine an alarm condition based on one or more logic statements, including but not limited to:
(1) The moisture condition within a conditioned zone is higher or inconsistent with the moisture conditions determined from—the reference zone;
(2) The relative humidity within a zone is higher than desired because the makeup ventilation air source is introducing moist air;
(3) The relative humidity within a zone is increasing faster than can be attributed to the rate of increase in the relative humidity within the makeup ventilation air source;
(4) The relative humidity within a zone is increasing faster than a predetermined rate;
(5) The relative humidity within a zone is higher than an allowable limit; or
(6) The recent time profile of the relative humidity within a zone is inconsistent with the historical time profile associated with the same space.
The last logic statement (6) assumes that the system has a method or capability to learn and recognize the time dependent behavior of the moisture levels in a building zone and the associated capability to monitor and compare a portion of the recent behavior to the historical profile, in the manner of pattern recognition. As used herein, the term “historical pattern” means that the system is designed to “learn” the moisture behavior patterns over time and then begin to compare the current behavior to historical norms. For example, it the moisture patterns always showed a spike in the morning and evening corresponding to people waking up a bathing or coming home and preparing supper, then these effects could be anticipated and included in the devices definition of what it thought was “normal”. Furthermore, as used herein, the term “preset range” means a range that has been independently determined to be appropriate for the particular building and occupancy situation by knowledgeable practitioners based on experience in similar applications and situations and through the use of engineering principals.
The particular threshold or limit values are dependent upon the final installation conditions, as do the time frames on which the alarm decisions are qualified or generated. Typically, individual relative humidity alarm thresholds associated with wood frame buildings would be on the order of 30% to 70%, depending on the exposure period (for instance, higher levels may be allowed for shorter intervals). However, thresholds outside this range may be relevant or desirable in certain situations.
Data smoothing and qualification is incorporated to help suppress short term variations that are expected in occupied, active buildings. Such filtering will also help minimize nuisance alarms induced by local weather and environmental changes that may not be of concern to the building. Typical smoothing time frames are on the order of hours although some applications may require times as short as minutes or as long as days. The method of the present invention includes measuring moisture content at least one selected location and ignoring changes that do not persist for periods longer than a preset time period. As used herein the term “preset time period” is defined as a period that has been independently determined to be appropriate for the particular building and occupancy situation by knowledgeable practitioners based on experience in similar applications and situations and through the use of engineering principals. Essentially, this is value is based on the body of knowledge available to the person who configures the system.
A further capability provided by this invention is the ability to suppress false alarms or otherwise qualify the generation of alarms using multiple moisture measurements and relating them using psychrometric principals. An example of how this helps prevent false alarms would be to consider the following scenario. Consider the case where there is a rise in the relative humidity in the outdoor air as a result of rain. In many cases, the outdoor air is the ultimate source of make up air for the building and the rise in its humidity will eventually propagate to the interior of the building and be reflected as a corresponding increase in indoor relative humidity. Simple humidity alarms with fixed level thresholds may trigger an alarm in this situation, whereas the system and process embodying the present invention can be configured to anticipate the rise in indoor humidity caused by the rise of humidity in the makeup air and in turn adapt the thresholds and rates it uses to determine an alarm condition.
It should be noted that within the context of this discussion, “make up” air may be primarily outdoor air or may be a mixture of air (or gas) from various sources that blend and refresh various building (or structure) spaces. These air sources may be provided intentionally (for example, a conventional make up air intake forming part of the building ventilation system) or may be inherent in the design, construction or condition of the building (for example, air introduced into the structure through infiltration). In any case, the make up air, when properly mixed and conditioned, represents the normal building air conditions. It is noted that the rate of air flow can be determined by any number of means known to the art such as moving vane or hot-wire anemometers, orifice flow meters, ranked sail switches or the like. The actual airflow data could be collected by or communicated into our disclosed system through many interfaces including one of the externalized signal inputs (for example through one of the scanned analog voltage reading inputs or digital inputs) or could alternately be provided to the system through various higher level digital means (such as a readings read through one of the available communication data ports). Once the system has knowledge of the flow rates at the various locations, basic engineering mass flow and material continuity calculations can be performed and used to relate the bulk flow of moisture through the affected building areas.
Of course, as indicated previously in this disclosure and for the purposes of this invention, the concept of relative humidity is only one of several possible and essentially equivalent representations of moisture content in the air. The above example situations could be alternately implemented and related in terms of:
(1) absolute, differential or relative humidity;
(2) absolute or relative water vapor pressure;
(3) equivalent dew point temperature; and/or
(4) changes in the moisture content of wood or other building materials including surface or bulk conductivity; or
(5) similar concepts, whether they be optionally pressure and/or temperature compensated. These and variations on these are representations known and accepted in the art.
The indicated calculations and decision logic can be based on an analysis of the underlying environmental behavior such as: rates of change in indoor and outdoor conditions; differences between indoor and outdoor moisture and temperature values; comparison with historical levels; and/or possibly through evaluating excursions outside of allowable values.
For instance, wood moisture content monitoring provides a useful mechanism to evaluate the humidity levels and history of the surrounding air to which the wood is exposed. Wood moisture content, especially its gradient with respect to the depth in the wood, gives a view of the longer-term humidity history of exposed wood members since moisture enters and leaves wood given time and a forcing gradient for the moisture (such as differences in vapor pressure). The long-term wood moisture content behavior can thus be used as another factor for assessing and diagnosing building moisture problems. As well and on its own merit, wood moisture is a useful indicator for the potential growth of mold and fungi on the wood and other materials.
More particularly, using various wood moisture measurement techniques, especially those that isolate the wood moisture characteristics at various depths into the affected section of wood, provides information on the moisture exposure history of the affected wood. As a simple example, consider the case where the specific conductivity values of a sample piece of wood are higher near the surface than deeper within the wood section. If this condition exists, then it can be taken that the wood has been exposed to increased moisture levels within a time frame consistent with the moisture permeation response time of the wood. That is, the moisture has not had time to permeate or equilibrate within the wood so as to increase the conductivity of the deeper wood elements.
Temperature monitoring is typically also included in this invention, since it provides both information on the ambient conditions and a reference value against which the humidity or moisture content measurements can be adjusted and interrelated, optionally by adjusting them all to equivalent values at a set of predetermined standard conditions. Localized temperature monitoring also provides for another useful function, that is temperature limit alarms, providing additional building protection through localized detection of high or low temperature conditions and/or possible freeze conditions.
Depending upon the number of sensors and the particulars of the building configuration, various zones or areas of detection can be developed to provide additional space specific information and localization of the diagnostic capability inherent in a such a sensor system.
These features can be incorporated into an automatic, microcomputer or microprocessor controlled instrument that combines real-time measurement and processing with multiple sensors and sensor locations to produce a system capable of effectively monitoring a building without frequent false alarms or through the intervention of an operator except in the case a response to a legitimate moisture problems.
As well as moisture monitoring, the devices can also be provided with the capability to monitor other externalized signal inputs and react to the alarm conditions or externalized signal inputs by activating control functions or outputs. Such features are useful to monitor contact closures of remote switches (such as water detectors or sail switches), analog input signals indicative of building activity and conditions and to provide control outputs to activate other equipment or pass messages to other systems. Devices embodying the present invention can include a number of general purpose digital and analogue inputs and outputs. In the figures, these are noted as “Externalized Signals (29)”. These can be used to allow other external signals to be monitored or as control outputs. For instance, a digital input could be connected to a water level switch in a sump pit to detect rising water levels so that the system could generate an alarm. A digital output could be used to activate some piece of external equipment such as a ventilation fan or sump pump. The analogue inputs are similarly useful for monitoring other external sensors that might be present in some situations, such as flow meters, tank level gauges and the like.
A further capability that can be incorporated into the system and process resulting from this invention is the ability to estimate the magnitude of the moisture problem. Since the system has knowledge of the moisture content and temperature of the air and since the system can be provided with information regarding the relative or absolute ventilation rates in the areas associated with each Sensing Station, the absolute evolution rate of moisture into the ventilation air in the zone associated with each Sensing Station can be determined through calculations know to the art. The information related to the ventilation rate may be based on:
(1) an a priori knowledge of the building design and characteristics;
(2) periodic site measurements entered into a database that is available to the computational elements of the invention; or
(3) may be measured by the system in a dynamic fashion, possibly through various sensors attached to the system via the Externalized Signal options discussed previously.
There are a number of specific applications that highlight the utility of this invention.
(1) Monitoring Low Traffic Building Areas:
(2) Crawl space and basement areas have been identified as building components that are prone to water leakage and other moisture management problems. Left unattended or not quickly addressed, these elevated moisture conditions can result in significant deterioration of the building infrastructure and contents, including the growth of mold and other biological contaminants. (see Figley et. al mentioned above and incorporated herein by reference)
(3) Monitoring Building Areas That Are Not Normally Occupied:
(4) Monitoring spaces other than traditional buildings which are either occupied or not occupied and which are subject to humidity damage and which are exposed to gas or gases other than air.
Similar to smoke detectors which provide an indication of an airborne smoke source somewhere in the area surrounding the sensor, this invention can provide early detection of moisture management problems in an affected zone. Since airborne humidity changes (particularly increases) will result from water leaks, detecting humidity changes provides information on moisture problems that have occurred somewhere along the path that the air or gas impacting on the detector has traveled. This is an advantage over a flood alarm system since airborne humidity migrates into the bulk air mass and is therefore detectable over a wider region. In contrast, a flood sensor must generally come directly in contact with liquid water to actuate the alarm.
Since it is often difficult to predict where a leak may occur and since leakage may not drain past a flood sensor, many leaks may exist that do not activate a flood alarm.
In these situations, the system and process embodying this invention will provide a more timely alarm because of the broad, integrated building or structure volume that can be sensed. The alarm can indicate that a leak or other moisture problem (such as component failure or vandalism) has occurred and will improve response time to address the problem. This will have broad applications to building monitoring, security and to reducing insurance and repair costs.
Monitoring Building Environments:
Long term monitoring of buildings (owned, rental or leased) can provide valuable information on building operation and operating practices to enhance long term maintenance and durability. Feedback can be provided to the building users to indicate if they are causing moisture problems in their course of daily activity.
Monitoring Remote or Unoccupied Buildings or other Structures:
This invention provides a valuable addition to remote and/or unoccupied building asset management systems since it allows a variety of diagnostics to be performed without an operator present. Remote access to the information produced by this invention, whether or not an alarm condition exists, can provide a building operator with valuable information.
Monitoring Buildings or Structures with Difficult or Dangerous Access:
The system and process embodied in this invention can provide a direct benefit to buildings where access to the monitored zones is difficult or dangerous which is the case in many structures. Examples include:
(1) crawlspaces with very low headroom where entry and movement is restricted;
(2) building spaces where dangerous goods, materials or substances may be present, such as chemical storage areas or facilities; or
(3) areas that have been restricted or cordoned off due to the possibility of contamination, such as service tunnels where asbestos insulation is present.
In these types of situations, physical inspections are possible but difficult and expensive to conduct in a safe manner. As such, a monitoring system would allow remote detection of problems which can reduce the need for operator exposure.
Referring to the figures, the system and process embodying the present invention will now be discussed in detail.
FIG. 1 shows one embodiment of the invention wherein the system consists of a Control Station 10 , a Reference Sensing Station 11 , and multiple Zone Sensing Stations 12 . Each Sensing Station makes a measurement or a surrogate measurement of the moisture present in the air 40 impinging on its Air Sensing Element 13 . In addition or conjunction with measuring the humidity or moisture content of the surrounding air, the Air Sensing Element may optionally include one or more of:
(1) a temperature sensor;
(2) a temperature compensation element;
(3) a barometric pressure sensor; or
(4) other mechanisms known in the art which allow measured moisture values to be compensated or alternately converted to equivalent values at a set of standard conditions.
The Sensing Stations also contain:
(1) a Signal Conditioning element 14 to interface with the Air Sensing Element and at various possible sub-sensors;
(2) a Local Control & Communication element 15 to allow for the acquisition and communication of measurements, convey system data and respond to or generate commands; and
(3) Signal Input & Output provisions 16 for acting on or reacting to Externalized Signals.
These capabilities and features can be implemented in a number of fashions such as electronic circuits or other means known to the art.
The Control Station contains:
(1) a simple Human Interface & Display element 17 to allow operator interaction with the system;
(2) a Remote Communication element 18 to allow the system to interact with other equipment and systems, possibly at a large distance;
(3) an element responsible for System Control & Diagnostics 19 to enable selfchecking and monitoring for proper system operation;
(4) a processing element 20 which implements the Calculating & Alarm Logic functions;
(5) a Zone Station Communication element 21 to exchange data and commands with the various Sensing Stations; and
(6) provisions 22 for acting on or reacting to Externalized Signals.
These capabilities and features can be implemented in a number of fashions such as electronic circuits or other means known to the art.
The Reference Sensing Station 11 is functionally and performance wise equivalent to a Zone Sensing Station 12 , the difference in naming arises from the physical location of the Sensing Station and the significance given to the data it produces. In the case of the Reference Sensing Station 11 , the station is located in a position wherein the values it produces are indicative of the ventilation air present at that location and that may be used to flush the other conditioned zone volumes, the purpose being to identify the range and variations in the normal conditions in the building so as to help suppress false alarms. Thus, the measurements from the Zone Sensing Stations 12 can be compared to the Reference Sensing Station 11 to determine if additional moisture is being introduced subsequent to the reference zone.
Although each of the Sensing Stations 11 or 12 are shown as being individually connected via connections 23 to the Control Station 10 , there are many other methods of intercommunication schemes known to the art, including but not limited to: peer-to-peer, master-slave, bussed or daisy chain connections, networks and data loops amongst others. No limitation on this invention is implied by the communication connections presented herein. The resulting moisture measurements, possibly including corresponding values of other parameters needed to relate the moisture measurements between stations, are conveyed to the Control Station 10 within which a decision algorithm resides to relate the moisture measurements to other moisture measurement values obtained by the Control Station 10 from other Sensing Stations 11 or 12 . Optionally or alternately, the Control Station may assesses the individual moisture measurements against one or more thresholds known to the Control Station 10 . The various circuits in the control and sensing stations will smooth the temporal characteristics of the measured values over one or more time frames to reduce the effects of measurement noise and/or short term moisture transients as discussed herein. Furthermore, the circuitry in any or all of the stations can include further circuitry which determines the relative rates of change in moisture content by converting each moisture content to an equivalent value of relative humidity that would be present in the affected air samples if they were at a predetermined set of standard temperature and pressure conditions, and/or which assesses the differential moisture content between smoothed sensed values of moisture content from the selected location and reference location where the time frames over which the two sensed values are smoothed may be different, and/or which measures moisture content for a second pre-set time period and ignores transient changes in moisture content that do not persist longer than that second pre-set time period.
Based upon a rule set and/or a series of defined relationships between moisture measurements or the history of the joint and several moisture measurements (in its entirety, defined as the decision algorithm), the system generates an alarm as required. The system may also optionally collect other information from the Sensing Stations, possibly from the Externalized Signals 29 which may feed into the decision algorithm. As well, either the Sensing Stations or the Control Station may actuate or act on an alarm or non-alarm condition via the Externalized Signal features optionally provided with each station.
FIG. 2 shows one configuration of a Sensing Station 11 or 12 wherein the subject moisture measurement is determined from a Relative Humidity sensor 24 in combination with a Temperature sensor 25 . The Signal Conditioning element 26 in this case is a relatively conventional excitation and amplifier system feeding into an analog to digital converter controlled by firmware 41 in a microcontroller (MCU) 27 . The MCU 27 provides the rapid local scanning capability and can be configured to produce results scaled in engineering units if desired. The MCU 27 also provides the Local Control & Communication functions 15 ( FIG. 1 ), with the communication being accomplished over a serial connection 28 . The Externalized Signal functions 29 includes analog and digital inputs as well as digital outputs so that limited process monitoring and control functionality can be accommodated at or near the Sensing Station.
Externalized Signals 29 may include such common functions as contact position detection (for example, to sense a sail switch in a ventilation ductwork system), to activate supporting equipment (for example, to turn on an additional fan or pump) or to measure an analog input (for example, to sense an analog level gauge).
FIG. 3 shows a conceptual block diagram of a simple one story building 30 with a mechanical room 31 , a single occupied zone 32 and a conditioned crawlspace 33 that has been divided into two zones. One possible embodiment of the invention is deployed within the structure.
Note that the Reference Sensing Station 11 is within the occupied building space. The reference moisture values thus obtained inherently contain moisture variations that result from both occupant behavior and from the make up air introduced as part of the conditioned air. Note also that the overall crawlspace ventilation flow is possibly and optionally a combination of both intentional ventilation and unintentional air leakage from conditioned or other building areas.
It is also noted that in the configuration shown in FIG. 3 , the Zone Sensing Stations 12 within the crawlspace component of the structure are located within the confluence of the air stream passing between zones 35 or adjacent to the crawlspace depressurization fan 36 . In this fashion, each of the Zone Sensing Stations is exposed to the moisture collected by the air as it passes through the crawlspace such that the Zone Sensing Station 12 can detect moisture in the zone without having to be in the immediate vicinity of or in intimate contact with the source of the moisture.
It should also be understood that the indicated crawlspace may also include basements, service ways, chases, tunnels and other such building elements that form part of the building structure or envelope and through which conditioned ventilation air is passed or conveyed.
As well, the application and embodiments associated with this invention can be extended to multi level or multiple story structures. In such buildings, there are service areas or levels positioned amongst or between occupied areas. These service volumes can be effectively monitored for moisture management problems. For example, in many hospitals, there are levels strategically placed between occupied floors wherein various services and infrastructure systems are located. These levels are confined, difficult to inspect and often full of equipment and systems that can leak water. This invention is well suited to monitoring these areas.
A more complex single floor building layout is shown in FIG. 4 . In this situation, the crawlspace is divided into several zones and there are two occupied areas of the building. Normally, air can enter each of the crawlspace zones either from the intended ventilation source 37 (including the possibly of air coming from an upstream zone) or from various unintentional sources such as leakage from other building zones 38 (induced by the pressure gradient from the crawlspace depressurization fan), from building infiltration from the exterior environment 39 or by combinations of the above.
The progression in complexity indicated going from the case in FIG. 3 to that in FIG. 4 can be further extended to more complex building structures and situations without departing from the scope of this disclosure or the claims appended hereto.
The ventilation methods and air flow configuration can be complicated, especially so in larger buildings. In some installation and use cases, it might be necessary to configure a system under this invention with multiple Reference Zone Stations 11 to accommodate multiple sources of makeup 34 or ventilation air, various ventilation isolated occupied areas or to accommodate other oddities of building mechanical and HVAC systems. It is often also the case that the make up air to any particular sensing zone can be directly supplied by a ventilation system or can include air that moves intentionally or unintentionally through a building because of design, building operation, environmental conditions or other prevailing conditions known to affect air flow in buildings. However, these scenarios are in principal extensions of the present invention and this disclosure should be taken as to include the possibility of addressing these needs using an appropriately configured system.
By way of illustration of how this system would help diagnose and isolate a moisture management issue within the building shown in FIG. 4 , consider the following scenarios.
1. If a significant water leak were present in crawlspace Zone #2 (perhaps resulting from a sewer or water line leak on the crawlspace side of the floor), then this would be detected as an unattributable humidity rise on the Zone #2 and #3 Stations, but not likely on any other Station. Depending on the severity and character of the leak, the problem might be detected based upon the local time rate of change of the humidity, the relative humidity at the Zone #2 or #3 stations exceeding a threshold value, or the standardized humidity at the Zone #2 or #3 stations differing from the expected humidity based on the Reference Zone.
2. If a water leak occurs in the mechanical room located above Zone #1, the water will typically penetrate the floor and run into Zone #1. In this case, the humidity in the mechanical room may or not rise significantly, depending on how much water surface is exposed to the air before the water migrates down through the floor. However, Zone #1 will capture the water penetrating from above which in turn will cause the Zone #1 Sensing Station to activate. The air movement from Zone #1 will increase the humidity in Zones #2 and #3, though often to a lesser extent, and the differences in the humidity measured at the various points will provide diagnostic information on the location of the moisture source.
3. If the outdoor humidity rises as a result of local weather conditions, all the Sensing Stations including both the Reference and Zone positions, should detect a corresponding rise in humidity. Under normal conditions, this would not generate an alarm unless the overall humidity remained high for an excessive period, at which time an alarm may be generated to advise the building operator to attempt dehumidifying the air entering the structure.
4. If the Zone Sensing Station in one of the occupied areas detects a high humidity condition (for example, exceeding a preset value determined in advance for the building and based on building specific criteria), the system will assess for a period and if the condition remains the same or worse, an alarm will be generated. However, in this scenario, the humidity may be the result of a legitimate problem or may be the result of occupancy. In either case the building operator should inspect the Zone and fix the problem or advise the occupant to modify their practices, as appropriate.
5. If the excess moisture is being introduced through an extended surface, such as a wet foundation wall or as moisture wicking up through the crawlspace floor as the result of high soil moisture content, then water may not be present in the crawlspace as a freely flowing or pooling liquid. In this case, a casual visual inspection of the crawlspace would not necessarily identify a moisture problem while traditional flood and leak detectors (such as sump alarms and floor wetting detectors) might not activate. However, the humidity will still increase as water present on the wetted surface is evaporated, and the device resulting from this invention will detect the problem or condition and warn the building operator.
A simplified measurement scan cycle and alarm decision algorithm sequence follows. In this simplified version, the sequence has been foreshortened to improve clarity. It should be understood that multiple sensors are involved and that other operational diagnostics will be occurring in tandem with the sequence described below.
The system will repeatedly scan the various Sensing Stations and calculate both the most recent versions of each Station's values as well as updating its knowledge of the recent history of and trends in the readings. The basic process is as follows:
Scan the measurement stations at a regular rate and update the smoothed version(s) of each of the returned measurement values. There may be more than one integration time constant associated with each parameter, for instance a short and long period version of each measurement value streams. It is noted that the integration time constant is directly related to the length of time that the average is determined over or “smoothed”. For the purposes of this invention, the act of integrating the instantaneous readings produces functionally the same effects as averaging and/or filtering the signal, so the terms are used somewhat interchangeably in the text. A longer integrating time constant roughly equates to including more readings into the average or alternately filtering the signal through a lower cutoff frequency low pass filter.
Smoothing a signal using a running geometric average is configured based on the underlying measurement update rate (or sampling rate) combined with the desired number of successive data samples which are to be included in the averages. For example, an average over two samples will have a shorter time constant than an average extending over several hundred samples. Conversely, slowing the sampling rate would increase the time constant since it would take longer to collect the next sample and thus would draw the averaging interval out. In practice, for simple systems, the sample rate is a predetermined or preselected value based upon various hardware and software design issues. However, the number of samples to include in an average is relatively flexible, and this is the mechanism utilized in this embodiment to adjust the relative duration of the integrating time constant. Longer time constants are useful for determining the overall behavior of the air mass, while shorter time constants can be used to monitor short term effects and improve response times. The best of both worlds is achieved when a combination of time constants are utilized which allows both short term excursions to be identified and to monitor long term trends.
The further step of adjusting the smoothed versions of each reading to standard conditions consists of using the noted psychrometric formulae to correct the various representations of each signal (the values smoothed over different time frames) to the equivalent relative humidity readings that would be obtained if all the measurements were taken at a set of standard temperature and air pressure conditions. This allows any inter comparison of the various moisture levels to be made on a common footing. Note that this treatment yields effectively the same results, as far as detecting moisture errors and alarm conditions, as would be obtained if absolute moisture calculations were performed, since the relative and absolute humidity are uniquely linked by the psychrometric behavior of water in air. This approach also allows making equivalent assessments with respect to the moisture mass balance and continuity through the building, for the same reasons noted in this disclosure.
Test the smoothed versions of each of the individual readings against various alarm threshold limits and alarm if appropriate. Note that alarms may be generated based on the amplitude of the smoothed values (including optionally one or more of absolute, relative and differential representations) or the time rate of change of the smoothed values (again including optionally one or more of absolute, relative and differential representations). Note also, that based upon the measurements being gathered from the Reference Station, the alarm function associated with individual reading excursions outside the corresponding limits may be automatically suppressed for a period to allow for expected transient excursions without generating an alarm.
Adjust the smoothed versions of each of the readings to standard conditions. Based upon the differences between each Zone Station and the Reference Station, generate alarms based optionally on either or both the smoothed differences and the smoothed rates of change.
Note that the time rate of change alarm functions and underlying calculations can be approximated and/or alternately implemented in a number of ways. One typical method would consist of keeping a sufficiently deep record of the history of a particular signal or signal calculation and computing the derivative by numerical means known to the art. However, this approach can be memory and computationally intensive given the calculating capacity of the low power electronics normally associated with monitoring systems. An effective alternative that does not require maintaining a detailed history of a signal or signal calculation is to assess the difference between the signal when it is filtered or averaged over both long and short time frames. Although not mathematically identical to calculating a derivative, this accommodation yields almost equivalent behavior with respect to the resulting alarm action. It is noted that the just-mentioned time frames are not fixed. An experienced person will identify appropriate long and short time frames based on their knowledge of how the building should behave. In typical buildings though, short could be a time frame of one to a few hours and long could be 8 to 16 hours, but these are just starter values. “Short” could be shorter or longer as could “long”. However, there would typically be a significant ratio between the short and the long periods, at least a factor of two or three, more likely a factor of 6 or 10.
By way of illustration, consider a single time varying input signal. For slow variations in the input signal, both the long and short time frame averages will have approximately the same value, since there is little difference between successive measurements. However, when the signal begins to vary on a time frame shorter than the response time of the longer period filter, the shorter period filter will converge while the longer filter response lags. The magnitude and duration of the difference between the long and short period filters is therefore representative of the time rate of change in the input signal, and in many cases may be used effectively as a surrogate. However, this invention does not necessarily prefer one method of assessing the time rate of change of a signal over another and no limitation in the invention should be taken based upon the manner that the time rate of change of a signal is assessed.
As used herein, the term “smoothed” is a generic term used to indicate that a value being used in a calculation is not an instantaneous reading determined from an input. Smoothing generally uses some fashion of integration to remove high frequency content in a signal to help suppress noise and fast transient errors in the underlying data stream. In analogue circuits smoothing can be done using analogue low pass filters that tend to smooth out the incoming signal. In digital circuits smoothing generally takes the form of some type of numerical running average, such as a “moving window” or similar technique. Many of these digital smoothing techniques require maintaining a record or history of the recent measurement values so that calculations can be repeated as each new reading is obtained. In the case of the moving window average, the calculation marches forward in time with older values falling out the far end of the window as new values enter at the front. This technique requires providing some sort of data queue where the newest data enters into the queue at one end and ripples the data down through the queue as each new entry is stuffed and eventually flushed the oldest data out the far end of the queue. Such queue's require a lot more memory depth (hence the reference to “deep”) to store all the data that will be included in each calculation cycle, which places a requirement on the system to have more memory available. This is especially cumbersome if the depth of the queue must be changed on-the-fly to accommodate changing integration times or smoothing intervals.
It is also noted that a practical alternative to the moving window style of averaging that is used in memory limited embedded processing applications, is to use a running geometric average, sometimes also referred to as a “leaky integrator”. This leaky integrator gives the most recent sample some proportional weight factor in the average and adds it to a fraction of the old average. The fraction of the old average and the proportional weight factor are designed to add to a numerical value of “one”.
The geometric averaging function typically looks something like:
New_Average = { Old_Average × ( Integration_Interval - 1 ) + New_Value } Integration_Interval where
the New_Average is the updated average, the Old_Average is the average from the last scan cycle and the Integration Interval is the number of samples in the average.
This function provides many of the same desirous integration or low pass filtering properties that are available with the moving window style averages, but requires far less memory to implement since all that is needed to calculate the latest average is the previous average value and the most recent data point.
The physical location of the processing functions and elements assumed in the foregoing discussion is, for convenience, taken as being resident in the Control Station. However, as is known in the art, processing functions and elements or parts thereof can reside in multiple, diverse and possibly redundant locations within a data acquisition and analysis system. This disclosure should not be read as being limited in these respects as many other computational layouts are compatible with and considered by this invention.
The foregoing discussion also makes reference to transforming the moisture levels measured at a Station to an equivalent value at a standard set of conditions. As an example of the calculations required to perform this conversion, consider a system wherein the moisture is assessed using Relative Humidity (RH) measurement concepts.
The RH values may be transformed between various temperatures, particularly from Station conditions to standard conditions through an intermediate evaluation of the absolute vapor pressure of water at each station which is then used to calculate what the equivalent RH would be under standard conditions. In this example, the calculations follow the pattern below.
The conversion starts with a calculation of the amount of water vapor, e, present in the air, as a fraction of the total water vapor, e s , that would be in the air if it were saturated with moisture at the same temperature and pressure. The relative humidity can be expressed as:
RH= e/e s (1)
Note that for discussion purposes in this simplified version of the RH analysis, it is assumed that the prevailing conditions at a Sensing Station will be restricted to a measured temperature range of 0° C. to 50° C. and to a measured relative humidity range of 5% to 95%. If measurement values are obtained that fall outside of these extremes, the RH analysis may be done using clamped values to constrain the behavior of the subsequent mathematical operations. This accommodation is made to restrict the complexity of the mathematical operations in the currently preferred device to remain within regions of the psychrometric behavior of water and water vapor in air that are well behaved. However, it should be understood that a more elaborate version of this discussion would include an extended version of the following formulations and computations that can provide conversions across all relevant operating conditions. This invention could be used and this invention should be read as to include the more elaborate version of the computations. At a temperature T (in ° C.), the saturation vapor pressures (T), in pascals (Pa), over liquid water, is calculated using the Magnus formula (slightly rearranged):
e s •T ° C. • =e ln•611.2••{17.62 T/(•243.12•T•}• (2)
For the specified range of temperatures, the values given by equation (2) are quoted as having an uncertainty of less than ±0.6 percent of value, at the 95% confidence level. The just-presented formula is disclosed in the above-referenced provisional patent application, the disclosure of which is incorporated herein by reference.
A more accurate but correspondingly more complex alternative formula for saturation vapor pressure (in Pa) at a given dew point temperature is (Note that T is now expressed in Kelvin) is:
e s • T ° K.•= e ••6096.9385T•1•21.2409642•2.711193×10•5T2•2.433502 ln T•• (3)
(Formulae due to Sonntag, 1990, updated from formulae given by Wexler, 1976 and 1977 and presented in the above-referenced provisional application the disclosure of which is fully incorporated hereinto by reference.)
The uncertainties associated with equation 3 are quoted as being less than 0.01 percent of value at the 95% confidence level.
The accuracy of these calculations depends slightly on the pressure and temperature of the gas concerned. For air near room temperature and atmospheric pressure, the water vapor enhancement factor, affects the result by approximately 0.5 percent of value.
In the preferred embodiments discussed herein, the above equations can be used to relate the humidity measured under various atmospheric conditions. However, these are just one example of how the conversion and comparison can be accomplished using the RH as the starting point. For Air Sensing Elements using different detection principals, other conversion mechanisms may be more appropriate. No limitation of this invention should be taken or implied through the presentation of this example, as other calculations and methodologies are known in the art to interrelate RH and other airborne moisture representations.
The method embodying the present invention thus includes the following steps and sequences:
Note that the following measurement process and the associated calculation sequences are an illustrative case and relate to the currently preferred embodiments as they are described herein. Other electronic configurations and data treatments methods are equally anticipated by this invention and can be shown to provide equivalent functionality.
Where reference is made to averaging calculations, it should be noted that there are analogue based electronic processing circuits that can accomplish these same goals, so that a comparable system could be developed using analogue design techniques. Further, within the field of analogue design, the functions of comparing a signal to a threshold or determining the difference between two signals as being within or exceeding a threshold are well known and could be used to implement an analogue version of this preferred embodiment.
No limitation on the disclosed invention should be taken by the use of terms indicating solely digital processing techniques.
(i) The System begins a scan cycle. The Control Station requests the moisture data from each sensing station (refer to FIG. 1 for an example of a physical configuration that allows this activity to occur).
(ii) Moisture data from each Sensing Station, including the Reference Sensing Station, is received by the Control Station. In this preferred embodiment, the data from each Sensing Station consists of the local Temperature and Relative. Humidity expressed in appropriate engineering units. Note that other representations of the moisture content of the air, such as the dew point, for each station's moisture readings could be used to similar effect.
(iii) The Control Station temporarily saves the data from each Sensing Station and calculates the effective Standardized Relative Humidity value that would be present at each Sensing Station, based upon each Sensing Stations recently reported relative humidity and temperature. The recent scan data from each Sensing Station is retained until the next scan cycle. At this point in the sequence, the Control Station has the most recent value of the Temperature, Relative Humidity and Standardized Relative Humidity from each Sensing Station at hand.
(iv) The Control Station updates the running geometric averages for each parameter of interest on an individual Sensing Station by Sensing Station basis. The running averages are determined over short, medium and long term time frames for the Temperature, Relative Humidity and Standardized Relative Humidity.
(v) The Control Station performs a series of conditional magnitude tests on the various running average results. The thresholds or preset values for these tests are configured as a table when the Control Station is commissioned. If any conditional test fails, an appropriate alarm is generated by the system. Individual tests can be effectively enabled or disabled by the choice of alarm threshold limits.
(vi) The Control Station performs a series of conditional magnitude tests on pairs of running averages. For example, the difference between the long and short term averages on a single Sensing Stations Relative Humidity value are assessed to detect a rapid rate of rise in the Relative Humidity at one location. Another example might be the difference between the long term average Relative Humidity at the Reference Sensing Station compared to the short term average Relative Humidity at a particular Sensing Station, to assess whether unexpected moisture was present at a Sensing Station location.
Because there are many possible combinations of pairs of averages (considering the number of Sensing Stations, the multiple averaging intervals and the raw and Standardized versions of the humidity parameters) the particular pairs of averages that are tested are defined when the firmware for the Control Station is created. However the thresholds that are applied during each test are configurable at system commissioning so that the sensitivity of each test can be adjusted. If any conditional test fails, an appropriate alarm is generated by the system. Individual tests can be effectively enabled or disabled by the choice of alarm threshold limits.
(vii) The system has completed one scan cycle and now waits for predetermined period (the scanning interval) before initiating another scan of the Sensing Stations. While waiting for the next measurement scan cycle to occur, the Control Station can perform other diagnostic and analysis functions which may require communicating with the Sensing Stations.
(viii) The system initiates another scan cycle and repeats the above sequence, updating the various averages as appropriate and repeating the indicated tests. This sequence continues indefinitely.
While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | A detection and monitoring method and system which makes it possible to detect the presence of moisture problems when they manifest as abnormal humidity in one or more discrete ventilation zones within a building envelope. The abnormal humidity can then be investigated and resolved or mitigated to minimize the potential for building damage or adverse occupant health effects occur. The present invention provides an early warning system that will alert personnel of the occurrence of a moisture problem. | 5 |
FIELD OF THE INVENTION
This invention pertains to an osmotic device. More particularly, the invention relates to an osmotic device for dispensing drugs that are irritants to mucosal tissue and the tissue of gastrointestional tract. Specifically, the device comprises a first and second compartment that act together for dispensing a diluted drug solution, thereby lessening the incidence of irritation to the tissues.
BACKGROUND OF THE INVENTION
There are many drugs known to pharmaceutical science that are used for producing a beneficial effect and have serious shortcomings associated with their use. For example, the electrolyte potassium chloride is the salt most frequently used when the action of the potassium cation is desired for an indicated therapeutic effect. Potassium chloride is used when hypokalemia exists, as a treatment with certain diuretics, in steroid therapy and for relieving the symptoms of Meniers's disease. However, serious shortcomings are associated with its use, mainly concentrated preparations of potassium chloride are an irritant to the gastrointestinal tract and its use often leads to bowel lesions. Another important drug that possesses similar shortcomings is aspirin. Aspirin, or acetalsalicylic acid, is widely used as an antipyretic and analgetic in a variety of medical conditions. Aspirin is a very potent drug; however, occult gastrointestinal bleeding often follows use of conventional, concentrated dosage forms of the drug. One additional example of a useful drug whose usefulness often is comprised by unwanted effects is indomethacin. Indomethacin is a nonsteroid indole that exhibits both analgesic and anti-inflammatory properties, and it is used for the treatment of rheumatoid arthritis. The most frequent untoward actions associated with concentrated dosage forms containing this drug are gastrointestinal disturbances similar to those mentioned above. In the light of this presentation, it will be appreciated by those versed in the dispensing art that if a device were made available for dispensing drugs in less than concentrated amounts, such a device would have a definite use and represent a valuable contribution to the art.
OBJECTS OF THE INVENTION
Accordingly, it is an immediate object of this invention to provide an osmotic device that overcomes the problems associated with the prior art and which device can be used for dispensing a drug to a biological environment of use.
Another object of the present invention is to provide an improvement in drug delivery by making available an osmotic device for the controlled and continous delivery of a beneficial drug in a diluted amount over a prolonged period of time.
Yet another object of this invention is to provide an osmotic device consisting of a first compartment that is a means for diluting the concentration of a drug solution that enters the first compartment from a second compartment, which diluted drug solution is then dispensed form the device.
Still another object of the invention is to provide an osmotic device that in operation in situ can significantly reduce the high concentration of a drug solution to a more dilute drug solution which diluted solution has a correspondingly decreased ability to produce injury to the tissues of the gastrointestinal tract.
Other objects, features, aspects and advantages of the invention will be more apparent to those versed in the art from the following detailed specification, taken in conjunction with the figures and the accompanying claims.
SUMMARY OF THE INVENTION
This invention concerns an osmotic device for dispensing a drug to an environment of use. The system comprises an outer semipermeable wall surrounding two adjoining compartments, forming one single-walled compartment and the other compartment surrounded by an additional inner semi-permeable wall forming a two-walled compartment. The outer wall possesses a greater permeability to the passage of fluid than the inner wall. A passageway in the outer wall connects the exterior of the device with the single-walled compartment, and a passageway in the inner wall connects the two compartments. A drug present in the two-walled compartment is released by the combined action of fluid being imbibed through the walls into each compartment, and at a greater rate into the single-walled compartment that into the two-walled compartment, thereby producing a solution in each compartment. The drug solution in the two-walled compartment passes through the passageway into the single-walled compartment and is diluted therein, with the diluted drug solution passing through the passageway form the single-walled compartment to the exterior of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which are not drawn to scale, but are set forth to illustrate various embodiments of the invention, the figures are as follows:
FIG. 1 is a view of an osmotic device designed for orally administering a beneficial drug to a warm-blooded animal;
FIG. 2a and FIG. 2b are opened views of FIG. 1, which Figures illustrate the compartments and structure of the device manufactured as an integrally formed device;
FIG. 3 illustrates an osmotic device provided by the invention designed for dispensing a drug in a body passageway such as the vagina or ano-rectal passageway.
In the drawings and specification, like parts in related figures are identified by like parts. The terms appearing earlier in the specification and in the description of the drawings, as well as embodiments thereof, are further detailed elsewhere in the disclosure.
DETAILED DESCRIPTION OF THE DRAWINGS
Turning now to the drawings in detail, which are examples of various osmotic delivery devices of the invention, and which examples are not to be considered as limiting, one example of an osmotic device is indicated in FIG. 1 by the numeral 10. In FIG. 1, device 10 comprises a body 11 that can be shaped, sized, adapted and structured for placement and prolonged retention in a biological environment of use for the controlled delivery of drug thereto. The dashed lines seen in FIG. 1 indicate the structure of device 10 as discussed below in FIGS. 2a and 2b.
In FIGS. 2a and 2b, device 10 is seen in full opened-section. In these Figures, device 10 comprises a body 11 having an exterior wall 12 that surrounds and forms a first compartment 13 and a second compartment 14. The second compartment 14 additionally is surrounded by an interior wall 15 that further defines and forms compartment 14. Both exterior wall 12 and interior wall 15 are formed of a semipermeable polymer that is permeable to the passage of an external fluid, and impermeable to the passage of both an osmotically effective solute and drug, but the rate of passage of fluid through exterior wall 12 is greater than the rate of passage through interior wall 15.
Device 10 has a pair of passageways. A passageway 16 in exterior wall 12 connects the first compartment 13 with the exterior of device 10, and a passageway 17 in interior wall 15 connects first compartment 13 with second compartment 14. Compartment 13 contains an osmotic effective agent or solute 18 that exhibits an osmotic pressure gradient across wall 12 against an external fluid and 18 is in direct contact with wall 12. Compartment 14 contains a drug 19 that exhibits an osmotic pressure gradient across wall 12 and wall 15 against an external fluid and 19 is in direct contact with interior wall 15. When, drug 19 exhibits limited solubility or it is substantially insoluble in the external fluid, drug 19 can be mixed with an innocuous osmotically effective solute that exhibits an osmotic pressure gradient across walls 12 and 15.
In operation, compartment 13 and compartment 14 operate together to delivery drug 19 from device 10. That is, external fluid is imbibed into compartment 13 in a tendency towards osmotic equilibrium at a rate controlled by the permeability of wall 12 and the osmotic pressure gradient across wall 12 to dissolve solute 18 and form osmotic solute solution 18a. External fluid is simultaneously imbibed into compartment 14 in a tendency towards osmotic equilibrium at a lesser rate than into compartment 13. The rate into compartment 14 is controlled by the permeabilities of walls 12 and 15 and the osmotic pressure gradient across walls 12 and 15 thereby dissolving drug 19 and forming drug solution 19a. Drug solution 19a is osmotically pumped from compartment 14 through passageway 17 into compartment 13 where it mixes with and is diluted by solution 18a. The diluted drug solution then is osmotically pumped from compartment 13 through passageway 16 to the exterior of device 10.
System 10 of FIG. 1 and FIGS. 2a and 2b can be made into many embodiments, including the presently preferred embodiments for oral use. Device 10 can be used for releasing either a locally or systemically acting therapeutic drug in the gastrointestinal tract over a prolonged period of time. Device 10 can have conventional oral shapes and sizes such as round with a diameter of 3/16 inch to 1/2 inch, or it can be shaped like a capsule having a range of sizes from triple zero, and from 1 to 8. In these forms, device 10 can be adapted for administering drug to numerous animals, avians, fishes and reptiles. The term animals as used herein includes warm-blooded animals, mammals and humans.
FIG. 3 shows an osmotic device 10 designed for placement in a body passageway, such as the vagina or the ano-rectal passage. Device 10 has an elongated, cylindrical, self-sustaining shape with a rounded lead end 20, a trailing base end 21, and it is equipped with a manually controlled cord 22 for easily removing device 10 from the body passage. Device 10 of FIG. 3 is structurally identical with device 10 of FIGS. 1, 2a and 2b, as described above, and it operates in a like manner. Device 10 of FIG. 3 in one embodiment contains a drug designed for absorption by the vaginal mucosa or the rectal mucosa.
While FIGS. 1 through 3 are illustrative of various devices that can be made according to the invention, it is to be understood those devices are not to be construed as limiting the invention, as the devices can take a wide variety of shapes, sizes and forms for delivering drug- to different biological environments of use. For example, the devices include buccal, implant, eye, artificial gland, cervical, intrauterine, ear, nose, dermal, subcutaneous and blood delivery devices. The devices can be used in hospitals, veterinary clinics, nursing homes, sickrooms, and the like.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the practive of the invention, it has now been found that osmotic delivery system 10 can be manufactured with a wall 12 formed of a material that does not adversely affect the osmotic solute, drug, animal or other host, and is permeable to an external fluid such as water and biological fluids while remaining impermeable to solutes and drugs. The selectively permeable materials forming exterior semipermeable wall 12 are materials insoluble in body fluids and they are non-erodible, or they can be made to bioerode after a preditermined period with the bioerosion occurring at the end of the drug delivery period. Typical materials for forming wall 12 include semipermeable polymers, also known to the art as osmosis membranes. The semipermeable polymers include cellulose acylate, cellulose diacylate, cellulose triacylate, cellulose ethers and cellulose esters. Typical semipermeable polymers include cellulose acetate, cellulose diacetate, cellulose triacetate, dimethyl cellulose acetate, cellulose acetate ethyl carbamate, and the like. Other semipermeable polymers include polyurethane, and selectively permeable polymers formed by the coprecipitation of a polycation and a polyanion. Generally, semipermeable polymers useful for forming wall 12 will have a fluid permeability of 10 -5 to 10 -1 (cc.mil/cm 2 ·hr·atm) expressed per atmosphere of hydrostatic or osmotic pressure difference across wall 12 at the temperature of use.
Further, in accordance with the practice of the invention, interior semipermeable wall 15 is independently selected from semipermeable homopolymers and semipermeable copolymers that exhibit different operable properties than the polymer forming wall 12. Representative materials suitable for forming wall 15 include polymeric cellulose esters and copolymeric cellulose esters such as mono, di and triacylates, and cellulose ethers. These materials include cellulose actate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose acetate propionate, cellulose acetate butyrate, cellulose trivalerate, cellulose dipalmitate, and the like.
Those versed in the art to which this invention pertains can select a semipermeable polymer for forming wall 12 that possesses a different degree of permeability to the passage of fluid that the semipermeable polymer forming wall 15 by using the following criterions. The scientific criterions are: (a) the polymer possesses a high degree of substitution, for example, the polymer has undergone etherification or esterification particularly acylation towards or to completion with the polymer formed demonstrating increased resistance to the passage of fluid; (b) the polymer exhibits a flux decrease with increasing molecular size of the substituting group, such as an ether or ester group; (c) the polymer exhibits a flux decrease proportional to the increase in size of the substituent, for example, the decrease occurs as the number of carbon atoms increase in a hydrocarbon moiety such as as alkyl or alkoxy moiety; (d) the polymer exhibits decreased flux with an increase in the degree of substitution of hydrophobic ether and larger hydrophobic ester groups; and (e) the polymer exhibits a flux decrease as the number of polar, ionic groups bonded to the polymer decreases.
The flux of a fluid, for example, the rate of water vapor transmission through various wall forming polymers also is ascertainable by using the procedure described in Diffusion in Polymers, pages 1 to 39, and then expressing the results of as WVTR, or water vapor transmission rate through a film of the polymer in grams/100 in 2 /24 hr/one mil thick film. Known WVTR values can also be found in Plastic Film Technology, by Park, W. W. R, 1969, published by Van Nostrand-Reinhold Inc., and in Diffusion in Polymers, by Crank J., and Park G. S., pages 274 to 276, published by Academic Press. Typical values are set forth in Table 1 immediately below wherein the film is the wall forming polymer and WVTR is as defined.
TABLE 1______________________________________Film WVTR______________________________________Polyvinyl alcohol 100Polyurethane 30-50Methylcellulose 70Cellulose acetate 40-75Ethylcellulose 75Cellulose acetate butyrate 50Polyvinylchloride, cast 10-20Polyvinylchloride, extruded 6-15Polycarbonate 8Polyvinylfluoride 3Ethylene vinyl acetate 1-3Polyesters 2Cellophane, polyethylene coated >1.2Polyvinylidene fluoride 1.0Polyethylene 0.5-1.2Ethylene propylene copolymer 0.8Polypropylene 0.7Polyvinyl chloride, rigid 0.7______________________________________
Another criterion that can be used for measuring the fluid permeability of different polymeric films consists in using a standard osmosis cell. The measurement is carried out by using the osmosis cell and measuring the rate of fluid through a membrane made of wall forming polymer having a known composition and thickness. The flow rate is determined by measuring fluid transport from a first chamber containing a fluid free of agent through a polymer membrane that separates it from a second chamber housing a solution containing a known concentration of a drug or a solute that exhibits an osmotic pressure gradient across the membrane. The flow measurement is preformed by adding to the first chamber the fluid and then adding to the second chamber, equipped with a stirring bar, the same fluid containing drug, and optionally containing an additional osmotic solute. The first chamber is connected through a conduit to a reservoir containing a supply of fluid, and the second chamber is connected to a vertically positioned tube of known diameter and calibrated with indicia that indicate the amount of fluid in the tube. In operation, fluid flows from the first chamber, through the membrane into the second chamber by osmosis causing the solution to rise over time, t, to give a volume displacement ΔV, during a time interval, ΔT. The volume, ΔT. The volume, ΔV, is read on the tube calibrated in cm 3 , and the time interval, ΔT, is measured with a stopwatch. The value k o π in cm 3 ·mil/cm 2 ·hr for the membrane with permeability, k o , for the drug solution with an osmotic pressure, π, is calculated from Equation 1, and wherein A o is the area of the membrane in the diffusion cell, and h o is the thickness of the membrane.
k.sub.o π=ΔV/Δt·ho/Ao Eq.1
If the measured value, k o π, approximates the calculated value, kπ, the membrane can be used for manufacturing the osmotic device. Osmotic flow procedures are described in J. App. Poly. Sci., Vol. 9, pages 1341 to 1362, 1965; and in Yale J. Biol. Med., Vol. 42, pages 139 to 153, 1978.
The osmotically effective solutes, or compounds, that can be used in first compartment 13 for the purpose of the invention include inorganic and organic compounds that exhibit an osmotic pressure gradient across a semi-permeable wall against an external fluid. Osmotically effective solutes useful for the present purpose include magnesium sulfate, lactose, mannitol, urea, inositol, carbohydrates such as raffinose, sucrose, glucose, lactose, sorbitol, mixtures thereof, and the like. The osmotic pressure of saturated solutions of various osmotically effective solutes and for mixtures of compounds at 37° C., in water, is listed in Table 2. In the table, the osmotic pressure π is in atmospheres, ATM. The osmotic pressure is measured in a commercially available osmometer that measures the vapor pressure difference between pure water and the solution to be analyzed and according to standard thermodynamic principles, the vapor pressure ratio is converted into osmotic pressure difference. In Table 2, osmotic pressures of from 30 ATM to 500 ATM are set forth, of course, the invention includes the use of lower osmotic pressures and higher osmotic pressures than those set forth by way of example in Table 2. Those versed in the art can easily select an osmotic solute, or determine the exhibited osmotic pressure of a drug with an osmometer. The osmometer used for the present measurements is identified as Model 302B, Vapor Pressure Osmometer, manufactured by the Hewlett Packard Co., Avondale, Pa.
TABLE 2______________________________________Compound or Osmotic PressureMixture ATM______________________________________Lactose-Fructose 500Destrose-Fructose 450Sucrose-Fructose 430Mannitol-Fructose 415Sodium Chloride 356Fructose 355Lactose-Sucrose 250Potassium Chloride 245Lactose-Dextrose 225Mannitol-Dextrose 225Dextrose-Sucrose 190Mannitol-Sucrose 170Sucrose 150Mannitol-Lactose 130Dextrose 82Potassium Sulfate 39Mannitol 38Sodium Phosphate Tribasic . 12H.sub.2 O 36______________________________________
The term drug as used in this specification and the accompanying claims include any physiologically or pharmacologically active substance that produces a localized or systemic effect, or effects in animals, including mammals, humans, primates, farm animals, sport animals and zoo animals. The active drugs that can be delivered include inorganic and organic compounds without limitation, these materials act on the nervous system, they are hypnotics, sedatives, psychic energizers, tranquilizers, anti-convulsants, muscle relaxants, antiparkinson, antipyretics, anti-inflammatory, analgesics, anesthetics, muscle contractants, hormones, steroids, anti-microbials, sympathomimetic, cardiovascular, diuretics, neoplastics, hypoglycemics, amino acids, ophthalmic, vitamins, and the like. The beneficial drugs, and the amount to be delivered are known to the art in Pharmaceutical Sciences, by Remington, 14th Ed, 1970, published by Mack Publishing Co., Easton, Pa.; and in The Pharmacological Basis of Therapeutics, by Goodman and Gilman, 4th Ed., 1970, published by The MacMillian Company, London.
The expression passageway as used herein comprises means and methods suitable for releasing the drug from the device, and for transporting drug from the second compartment to the first compartment. The expression includes aperture, orifice, bore, or a passageway formed in situ by eroding a water soluble plug, such as a gelatin plug. A detailed description of osmotic passageway, that permits the device to function according to osmotic principles, and the maximum and minimum dimensions for a passageway are disclosed in U.S. Pat. Nos. 3,845,770 and 3,916,899.
The devices of the invention are manufactured by standard techniques. For example, in one embodiment drug housed in the second compartment and a solvent are mixed into a solid, semi-solid or pressed into a shaped form, by conventional methods. The techniques used to make the drug forming compartment include ballmilling, calendering, stirring or rollmilling, and then pressed or tableted into a preselected shape. The wall forming material can be applied by molding, spraying or dipping the pressed shape into the wall forming material. In another embodiment, a wall can be cast, shaped to the desired dimensions that surround compartment 14, the compartment filled with drug, closed and a passageway drilled through the wall. An exterior wall can then be cast, shaped to the desired dimensions to surround and form compartment 13 and 14. Finally, compartment 13 is filled with an osmotic solute, and a passageway drilled through the exterior wall connecting compartment 13 with the exterior of the device.
In a presently preferred embodiment, the device is made by using air suspension techniques. This procedure consists in compressing drug, and then suspending and tumbling the drug in an interior wall forming composition until this wall is applied around the drug. Next, after drying, a passageway is drilled in this wall. Then, an osmotic solute is compressed over the side of the wall having the passageway, and the article returned to the air suspension machine, suspended and tumbled in a current of air until the external wall is formed around the two compartments. After drying, a passageway is drilled in the external wall connecting the solute compartment with the exterior of the device. The air suspension procedure is described in U.S. Pat. No. 2,799,241; in J. Am. Pharm. Assoc., Vol. 48, pages 451 to 459, 1959; and ibid., Vol. 49, pages 82 to 84, 1960. Other wall forming techniques such as pan coating can be used in which materials are deposited by successsive spraying of the polymer solution on the drug, or solute, accompanied by tumbling in a rotating pan. Other standard manufacturing procedures are described in Modern Plastics Encyclopedia, Vol. 46, pages 62 to 70, 1969; and in Pharmaceutical Sciences, by Remington, 14th Ed., pages 1626 to 1678, 1970, published by Mack Publishing Company, Easton, Pa. Generally, the exterior and interior wall will be about 2 to 6 miles thick. Of course, thinner and thicker walls are within the scope of the invention.
Exemplary solvents suitable for manufacturing the walls include inert inorganic and organic solvents that do not adversely harm the wall forming materials, the drug, the agent, and the final device. The solvents broadly include aqueous solvents, alcohols, ketones, esters, ethers, aliphatic hydrocarbons, halogenated solvents, cycloaliphatic aromatics, heterocyclic solvents, and mixtures thereof. Typical solvents include acetone, diacetone alcohol, methanol, ethanol, isopropyl alcohol methyl acetate, ethyl acetate, methyl isobutyl ketone, n-hexane, ethylene glycol monoethyl acetate, carbon tetrachloride, methylene chloride, ethylene dichloride, propylene dichloride, cyclohexane, mixtures such as acetone and water, acetone and methanol, acetone and ethyl alcohol, methylene dichloride and methanol, ethylene dichloride and methanol, and mixtures thereof.
DESCRIPTION OF EXAMPLES OF THE INVENTION
The following examples are merely illustrative of the present invention, and they should not be considered as limiting the scope of the invention in any way, as these examples and other equivalents thereof will become more apparent to those versed in the art in the light of the present disclosure, the drawings and the accompanying claims.
EXAMPLE 1
An osmotic delivery device for delivering potassium chloride at an osmotically-controlled rate is made as follows: first, 500 mg of commercially-available, dry powdered potassium chloride is compressed by standard compression techniques using a 3/8 inch punch. The compressed mass is then coated with a 3.5 mil thick of the inner wall forming polymer, consisting of commercially available cellulose acetate having an acetyl content of 38.3%. The wall is formed from a 80 to 20 parts by weight mixed methylene chloride-methanol solvent. A Wurster air suspension machine is used to form the wall. Next, the solvent is evaporated in an oven at 50° C. for 48 hours, and after cooling to room temperature, a 7.5 mil passageway is laser drilled through the wall. A drop of non-toxic blue dye is dropped onto the wall surface with the passageway as a guide for positioning the first compartment and the passageway in the first compartment.
Next, 250 mg of commercially available sucrose is compressed onto the surface with the passageway and the assembly returned to the air suspension machine. The assembly is then coated with exterior wall forming commercially available cellulose acetate having an acetyl content of 32%. A 5% polymer solution in dioxane is used to produce the exterior wall, which has a thickness of about 7 mils. After drying, a passageway is laser drilled through the exterior wall connecting the first, or osmotic solute compartment with the exterior of the device.
EXAMPLE 2
The procedure of Example 1 is repeated and the conditions are as disclosed, except that the drug compartment houses a glucocorticoid steroid selected from the group consisting of betamethasone, cortisone acetate, dexamethasone, fluprednisolone, hydrocortisone, methylprednisolone, paramethasone, prednisolone, prednisone and triaminicinolone hexacetonide, mixed with the osmotic effective solute fructose, and the first or solute compartment houses a mixture of the osmotically effective solutes sucrosefructose.
EXAMPLE 3
A non-stirring rate dependent osmotic device that releases a diluted drug solution independent of the pH of the environment is manufactured as follows: first, 125 mg of the diuretic ethacrynate sodium is compressed into a solid mass in a commercially available Manesty tableting machine to a Stoke's hardness of 8 kg. Next, the solid is coated in a standard air suspension machine with the semipermeable polymer cellulose acetate having an acetyl content of 38.3%. A 90% methylene chloride 10% methanol chloride solvent is used for forming the wall, and excess solvent is evaporated at 50° C. for 40 hours. The freshly formed wall has a thickness of 5 mils, and a 7 mil passageway is drilled through the wall.
Next, 350 mg of an osmotically effective composition consisting of dextrose and fructose is pressed in the Manesty machine to a Stoke's hardness of 8 kg. The pressed composition has a shape identical to the shape of the drug compartment. Then, a small drop of liquid cellulose acetate is spread around the outer edge of one surface of the pressed composition, and this surface is placed against the corresponding surface of the drug compartment with the passageway, with care taken to keep the passageway open. The two united masses are then coated in the air suspension machine with a wall of semipermeable acetate to a thickness of 10 mils. The wall is formed from a 5% solution consisting essentially of cellulose acetate having an acetyl content of 32%. The solution is made by dissolving 155 g of cellulose acetate in a solvent consisting of 3300 ml of acetone and 330 ml of water. The acetone and water have a 88.5 to 11.5 weight to weight basis. Finally, an osmotic passageway having a diameter of 10 mils is drilled through one exterior wall facing the mixed solutes for delivering diluted drug from the device.
EXAMPLE 4
The procedure of Example 3 is repeated in this example with conditions as described, except the drug in the drug compartment is a member selected from the group consisting of acetohexamide an ibuprofen mixed with the osmotic solute mannitol.
The novel osmotic system of this invention uses means for obtaining the delivery of drug at reduced concentrations to the environment of use while simultaneously maintaining the benefits of the drug and the integrity of the delivery device. While there are described and pointed out features of the invention as applied to presently preferred embodiments, those skilled in the art will appreciate that various modifications, changes, additions, and omissions in the devices illustrated and described can be made without departing from the spirit of the invention. | An osmotic device is disclosed for dispensing a drug. The device comprises an exterior wall surrounding a first and second compartment. The first compartment is in contact with the exterior wall and the second compartment is surrounded by an interior wall that is in contact with the exterior wall. A passageway exists through the exterior wall connecting the first compartment with the exterior of the device, and a passageway exists through the interior wall connecting the second with the first compartment. The first compartment contains an osmotic solute that exhibits an osmotic pressure gradient across the wall against an external fluid, and the second compartment contains a drug that exhibits an osmotic pressure gradient across the wall against the fluid. The exterior and the interior walls are permeable to the passage of the fluid, and they are impermeable to the passage of solute and drug, but the rate of fluid, permeability is greater through the exterior than through the interior wall. In operation, fluid in imbibed through the walls into the compartments and at a greater rate into the first compartment forming a more dilute solution therein than the drug solution formed in the second compartment, said drug solution passing from the second compartment through the passageway into the compartment and being diluted in the first compartment, with the diluted drug solution passing from the first compartment through the passageway to the exterior of the device. | 0 |
RELATED APPLICATION
The present application claims priority to U.S. provisional patent application 60/691,181, filed Jun. 17, 2005, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to methods and systems for digital signal compression, coding and representation, and more particularly to methods and systems using multi-frame motion estimation (ME). It further relates to a computer program product, such as a recording medium, carrying program instructions readable by a computing device to cause the computing device to carry out a method according to the invention.
BACKGROUND
Due to the huge size of the raw digital video data (or image sequences) used by present day multimedia applications, compression must be applied to such data so that it can be transmitted and stored. There have been many important video compression standards, including the ISO/IEC MPEG-1, MPEG-2, MPEG-4 standards and the ITU-T H.261, H.263, H.264 standards. The ISO/IEC MPEG-1/2/4 standards are used extensively by the entertainment industry to distribute movies, digital video broadcast including video compact disk or VCD (MPEG-1), digital video disk or digital versatile disk or DVD (MPEG-2), recordable DVD (MPEG-2), digital video broadcast or DVB (MPEG-2), video-on-demand or VOD (MPEG-2), high definition television or HDTV in the US (MPEG-2), etc. The MPEG-4 standard is more advanced than MPEG-2 and can achieve high quality video at lower bit rate, making it very suitable for video streaming over internet, digital wireless network (e.g. 3 G network), multimedia messaging service (MMS standard from 3 GPP), etc. MPEG-4 is accepted into the next generation high definition DVD (HD-DVD) standard and the MMS standard. The ITU-T H.261/3/4 standards are designed for low-delay video phone and video conferencing systems. The early H.261 standard was designed to operate at bit rates of p*64 kbit/s, with p=1, 2, . . . , 31. The later H.263 standard is very successful and is widely used in modern day video conferencing systems, and in video streaming in broadband and in wireless network, including the multimedia messaging service (MMS) in 2.5 G and 3 G networks and beyond. The latest standard, H.264 (also called MPEG-4 Version 10, or MPEG-4 AVC) is currently the state-of-the-art video compression standard. It is so powerful that MPEG decided to jointly develop with ITU-T in the framework of the Joint Video Team (JVT). The new standard is called H.264 in ITU-T and is called MPEG-4 Advance Video Coding (MPEG-4 AVC), or MPEG-4 Version 10. H.264 is used in the HD-DVD standard, Direct Video Broadcast (DVB) standard and probably the MMS standard. Based on H.264, a related standard called the Audio Visual Standard (AVS) is currently under development in China. AVS 1.0 is designed for high definition television (HDTV). AVS-M is designed for mobile applications. H.264 has superior objective and subjective video quality over MPEG-1/2/4 and H.261/3. The basic encoding algorithm of H.264 [1] is similar to H.263 or MPEG-4 except that integer 4=4 discrete cosine transform (DCT) is used instead of the traditional 8=8 DCT and there are additional features include intra prediction mode for I-frames, multiple block sizes and multiple reference frames for motion estimation/compensation, quarter pixel accuracy for motion estimation, in-loop deblocking filter, context adaptive binary arithmetic coding, etc.
Motion Estimation is the core part in most video compression standards such as MPEG-1/2/4 and H.261/3/4, to exploit temporal redundancy, so its performance directly affects the compression efficiency, subjective video quality and coding speed of a video coding system.
In block matching motion estimation (BMME), the most common measure of the distortion between the current block and the reference block in ME is the sum of absolute difference (SAD), for an N×N block, defined as:
SAD ( mvx , mvy ) = ∑ m = 0 , n = 0 N - 1 F t ( x + m , y + n ) - F t - 1 ( x + m + mvx , y + n + mvy )
where F t is the current frame, F t−1 is the reference frame and (mvx, mvy) represents the current motion vector (MV). For a frame with width=X, height=Y, and block size=N×N, the total number of search points at which the SAD needs to be evaluated in order to find the optimum motion vector in a search range equal to ±W is:
( X N ) ( Y N ) ( 2 W + 1 ) 2 ,
which is equal to 1673100 for X=352, Y=288, N=16 and W=32. This is a huge number that can consume huge computation power in a video encoder. Many fast algorithms [2]-[9] have been proposed to reduce the number of search points in ME, such as Three-Step Search (TSS) [11], 2D log Search [12], New Three-Step Search (NTSS) [3], MVFAST [7], and PMVFAST [2]. MVFAST and PMVFAST significantly outperform the first three algorithms as they perform center-biased ME using a median motion vector predictor as a search center and hence reduce the number of bits for MV encoding by smoothing the motion vector field.
The PMVFAST algorithm (which is a significant improvement on MVFAST and other fast algorithms, and thus was accepted into MPEG standard [10]) initially considers a set of MV predictors, including median, zero, left, top, top-right and previous co-located MV predictor. FIG. 1 illustrates the locations of the locations of the current block, the left block, the top block, the topRight block, the topRightRight block, and the right block (which is a “future block”, i.e. a block which is processed after the current block). It computes the SAD cost for each prediction. In later developments, PMVFAST was modified to compute the RD (Rate Distortion) cost [13] instead of the SAD cost using the following cost function:
J ( m,λ motion )=SAD( s,c ( m ))+λ motion ( R ( m−p )) (1)
where s is the original video signal and c is the reference video signal, m is the current MV, p is the median MV predictor of the current block, λ motion is a Lagrange multiplier and R(m−p) represents the bits used to encode the motion information. The next step in PMVFAST is to select the MV predictor that has minimum cost, and perform large or small diamond searches based on the value of the minimum cost obtained from the MV predictors.
A separate but important issue in defining current video coding standards, is the use of subpixel motion vectors including half-pixel, quarter-pixel or perhaps even ⅛-pixel motion vectors, which give more accurate description of motion and can give a PSNR gain of about 1 dB over integer-pixel motion estimation. With half-pixel precision, motion vectors can take on uniformly-spaced location values such as 0.0, 0.5, 1.0, 1.5, 2.0, etc. With quarter-pixel precision, motion vectors can take on location values such as 0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, etc. With ⅛ pixel precision, motion vectors can take on location values such as 0.000, 0.125, 0.250, 0.375, 0.500, 0.625, 0.750, 0.875, 1.000, 1.125, 1.250, 1.375, 1.500, 1.625, 1.750, 1.875, 2.000, etc.
It is well known that motion vector distribution tends to be center-biased, which means that motion vectors tend to be very close to (0, 0). This is shown in FIG. 6 ( a ), which shows the motion vector distribution in Foreman sequence using the Full Search (FS) algorithm for (0,0) MV. In addition, as shown in FIG. 6( b ), the motion vector distribution is also biased towards the median predictor (medianMV) which is the median of the motion vectors for the left block, top block and topright block shown in FIG. 1 . In addition, the motion vector is also biased towards the adjacent motion vectors (leftMV, topMV, topRightMV) in the current frame and the collocated motion vector (preMV) in the previous frame, as shown in FIG. 6( c ). It is also biased towards the bottom-right motion vector (preBottomRightMV) in the previous frame, as shown in FIG. 6( d ). These can all be considered predictors for the motion vector of the current vector and they can be used in PMVFAST.
SUMMARY OF THE INVENTION
The present invention aims to provide new and useful techniques for motion estimation, suitable for use in methods and systems for digital signal compression, coding and representation
In particular, the present invention seeks to provide new and useful effective and efficient motion estimation techniques, which may for example be applied in MPEG-1, MPEG-2, MPEG-4, H.261, H.263, H.264 or AVS or other related video coding standards.
A first aspect of the invention is based on the realisation that the motion estimation of the PMVFAST algorithm, although certainly an advantage over prior techniques, is not optimal. In principle, for each frame in a video, there exists a motion vector field {m i,j ,i=0 . . . M−1,j=0 . . . N−1} that globally minimizes the total RD cost for the whole frame:
total_RD _Cost = ∑ i = 0 M - 1 ∑ j = 0 N - 1 [ SAD ( s i , j , c ( m i , j ) ) + λ i , j ( R ( m i , j - p i , j ) ) ] ( 2 )
where (i,j) represents the (i,j)-th block in a frame which contains M×N blocks. For fixed Q p (which is a quantization parameter), λ i,j =λ=constant, and
p i,j =median( m i,j−1 ,m i−1,j ,m i−1,j+1 ) (3)
However, to consider the total RD cost for the whole frame simultaneously requires an exponential order of computational complexity, which is not practical. Thus, PMVFAST and all other known algorithms consider only the RD cost for only one block at a time, instead of all the blocks in a frame.
In particular, neither MVFAST nor PMVFAST takes into account that when a motion vector is being derived in respect of a current block, this causes a change in the median MV predictor for the next block. This can affect the smoothness of the whole motion vector field.
In general terms, the first aspect of the present invention proposes a new ME algorithm by improving the cost definition of PMVFAST and the choice of motion predictor candidates. In particular, for each current block of a first image (the current block may be 16×16, 16×8, 8×16, 8×8, 4×8, 8×4, 4×4, or other rectangular size, or even non-rectangular), a similar block of a second image (the reference image) is chosen based on a cost function which includes both: (i) a term which is a dissimilarity measure (e.g. SAD, SAE) of the current block and the similar block, and (ii) a term which is a function of at least a prediction of the motion vector for a future block of the first image.
In particular, the proposed algorithm may make it possible to improve the motion field smoothness by involving the current median MV predictor, and also an estimated median MV predictor of future (i.e. as yet unprocessed) coding blocks.
Many are variations of the invention are possible. In particular, the blocks may be of any size and any shape.
There may be multiple second images (i.e. multiple references) and the search may include candidate locations in all the second images.
Furthermore, the novel cost function may be performed for a number of sub-blocks which together constitute a larger region of the first image, and which are encoded in a coding order defined by a coding number. These sub-blocks need not be of the same size or shape.
The invention has a further aspect which may be used in combination with the first aspect of the invention or separately. In general terms, the second aspect of the invention proposes that when encoding a current block of a first image (the current block may be 16×16, 16×8, 8×16, 8×8, 4×8, 8×4, 4×4, or other rectangular size, or even non-rectangular), this is done using motion vectors which are selected having location values (i.e. respective components in the two axial directions) which are selected from a set of values different from those used than in known techniques.
Consider one possible motion vector predictors: (0,0). Whereas the conventional technique of full integer pixel allows motion vectors to take on location values such as −2.0, −1.0, 0, 1.0, 2.0, etc., the second aspect of the invention proposes to modify the set of possible location values close to the predictor. For the location value of 1.0 which is nearest to 0, we can use another location value such as 0.85 such that the allowable location values would include −2.0, −0.85, 0, 0.85, 2.0, etc. The advantage of this is that statistically motion vectors tend to be close to 0. And thus by choosing the location closer to 0, we would be closer to the true motion vector and thus can give better motion compensation that can lead to higher compression efficiency.
Thus, in one specific expression of the invention, the set of possible locations values for at least one axial direction may be chosen such that they cannot all be written as Lm where m=− . . . , 2, −1, 0, 1, 2 . . . and L is a constant (e.g. 1 pixel spacing, one-half pixel spacing, or one-quarter pixel spacing); that is, the location values are non-uniform. Specifically, the set of possible location values for at least one axial direction may be chosen such that they cannot all be written as m/n where m=− . . . , 2, −1, 0, 1, 2 . . . and n is 1 or a power of 2.
Note that the second aspect of the invention is not limited to choosing location values from a set of non-uniformly spaced location values; nor is it limited to selecting only the two location values closest to zero as compared to the conventional set of location values. As an example, in another example of the second aspect of the invention the location value 2.0 can be changed to 1.9 such that the allowable location values would include −1.9, −0.85, 0, 0.85, 1.9, etc.
Thus, in an alternative specific expression of the second aspect of the invention, the set of possible location values (for at least one of the directions) is chosen to include one or more location values which can be written as LA m m/n, where m=− . . . , 2, −1, 0, 1, 2 . . . , n is 1 or a power of two, L is a constant (e.g. 1 pixel spacing, one-half pixel spacing, or one-quarter pixel spacing), and A m is a value (optionally different for different values of m) which is less than 1 but which is at least 0.75, more preferably at least 0.80, and most preferably at least 0.85.
We have found that the optimal value(s) of A m depend upon the video.
One advantage of certain embodiments of the second aspect of the invention is that the motion vectors they produce can be encoded in the same format code as in conventional algorithms, except that the conventional codes for the location values should respectively be interpreted as the possible location values used by the embodiment. For example, if the location values used by a certain embodiment are: −1.9, −0.85, 0, 0.85, 1.9, etc, then the conventional code for the location value 1.0 should be interpreted as 0.85, and the conventional code for the location value 2.0 should be interpreted as 1.9, etc.
A method according to the second aspect of the invention may include the steps of defining a search region, defining within the search region a plurality of candidate locations including a set of a plurality of locations defined by the novel location values of the second aspect of the invention. These location values are the values of the corresponding displacements of the candidate locations from a key location (e.g. the (0,0) motion vector location, the predicted-motion vector, etc). For each candidate motion-vector, we calculate a cost function which is a function of a similarity measure (e.g. SAD, SAE) between the current block in the first image and the block at the said candidate motion-vector in the second image. Optionally, it may also be a function of the following motion vectors: the said candidate motion-vector, the current predicted-motion-vector, and optionally, as in the first aspect of the invention, one or more future predicted-motion-vectors. For example, optionally the cost function may be given be as in the first aspect of the invention.
BRIEF DESCRIPTION OF THE FIGURES
Embodiments of the invention will now be described for the sake of example only with reference to the following figures, in which:
FIG. 1 illustrates the current block, the left block, the top block, the topRight block, the topRightRight block, and the right block;
FIG. 2 . shows the typical distribution of Diff which is the difference between
m
i
,
j
+
1
-
p
i
,
j
+
1
and
m
i
,
j
-
p
i
,
j
+
1
;
FIG. 3 a shows the search pattern of large diamond search as used in a first embodiment of the invention;
FIG. 3 b shows the search pattern of the modified large diamond search as used in a first embodiment of the invention;
FIG. 4 shows the search pattern of small diamond search as used in the first embodiment of the invention;
FIGS. 5 a and 5 b compare the smoothness of the MV field of PMVFAST and the first embodiment of the invention;
FIG. 6 shows the motion vector distribution in Foreman sequence using the Full Search (FS) algorithm for (a) (0,0) MV, (b) median MV, (c) adjacent MV in current frame and collocated MV in previous frame, (d) bottom-right MV in previous frame (PreBottomRightMV); and
FIG. 7 is a flow diagram of the first embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The first embodiment of the invention employs many features of the PMVFAST algorithm, but improves upon PMVFAST (and other existing algorithms) by considering a few neighboring blocks instead of just one block. Eqn. (2) and (3) show that the choice of the MV of the current block directly affects the RD cost of the neighboring blocks, including the right block (or the (i, j+1) th block), the lower-left block (or the (i+1, j−1) th block), and the lower block (or the (i+1, j) th block). This is because the current MV would affect the predicted MV of these neighboring blocks and thus in turn affect the optimal motion vectors for those blocks. These are “future” blocks as motion estimation has not been performed on them when the current block is processed. We cannot compute the optimal motion vector of these future blocks concurrently with the current block because this we would require computing the optimal motion vectors for all the blocks in the whole frame simultaneously as in Eqn. (2), which would incur excessive complexity.
Instead, to assess the implication of the choice of the current MV for the current block on the right block or the (i, j+1) th block, we might add to the RD cost function of the current block of Eqn. (1) a term
R (| m i,j+1 −p i,j+1 |), (4)
where m i,j+1 is the optimal motion vector of the right block based on the current MV of the current block, and P i,j+1 is the median MV predictor for the right block based on the current MV of the current block, i.e.
P i,j+1 =median( m i,j ,m i−1,j+1 ,m i−1,j+2 ) (5)
However, m i,j+1 in Eqn. (4) is unknown as the motion estimation for the right block (a future block) has not been performed yet. However, we observe that
m i , j + 1 - p i , j + 1
can be approximated well by
m i , j - p i , j + 1 .
Let Diff be
m i , j + 1 - p i , j + 1 - m i , j - p i , j + 1 .
We performed experiments on many video test sequences and studied the distribution of Diff. The typical result is heavily biased towards zero as shown in FIG. 2 , which shows the probability density function (PDF) for the Foreman sequence. This implies that the two quantities are almost identical in most of the cases (identical in about 70% of the cases and differ by only 1 in about 23%). This suggests that
m i , j - p i , j + 1
is a good approximation of
m i , j + 1 - p i , j + 1 .
As a result, R(|m i,j+1 −p i,j+1 |) can be approximated by W*R(|m i,j −p i,j+1 |), where W>0. Likewise, we may add additional terms to the cost for the lower-left and lower blocks.
For the (i,j) th block, let medianMV denote the Median MV predictor given by Eqn. 3. Let FmedianMV denote the future median MV predictor (median MV predictor for the right block) given by Eqn. (5). Consequently, FmedianMV is a function of the MV candidate. The first embodiment is here referred to as the “Enhanced Predictive Motion Vector Field Adaptive Search Technique” (E-PMVFAST) for the (i,j)-th block.
The steps of the embodiment are follows. They are also shown in FIG. 7 .
For any candidate MV, define Cost as follows.
Cost(MV)≡SAD+λ*[ w*R (MV−medianMV)+(1 −w )* R (MV− F medianMV)] (6)
1. Compute Cost for three motion vector predictors: (i) the median MV predictor (“medianMV”), (ii) the estimated motion vector for the right block (“futureMV”) defined as
futureMV=median(TopMV,TopRightMV,TopRightRightMV)
and (iii) the MV predictor from a past block (“pastMV”), which is the one of the previous co-located MV (“PreMV”) and Previous-Bottom-Right MV (“PreBottomRightMV”) that is farther away from medianMV, i.e.
pastMV≡arg max MVε{PreMV,PreBottomRighMV} {abs (MV−medianMV)}
Note that item (ii) can be supplemented or replaced by an estimated motion vector for another neighbouring future block, such as the bottom-left, bottom, and/or bottom-right. Note also that in item (iii), the Previous-Bottom-Right MV can be supplemented or replaced with by a previous MV predictor for another neighbouring block. Note that items (ii) and (iii) form independent aspects of the invention. If any of the above MV predictors is not available (e.g. at frame boundaries), then skip that predictor.
2. If the smallest Cost of the motion vector predictors is less than a threshold T1, then stop the search and goto step 7. Otherwise, choose the motion vector with the smallest Cost as currentMV (current MV) and goto the next step. Note that, the Cost of the 3 motion vector predictors can be computed in some predefined order (e.g. medianMV, followed by futureMV, followed by pastMV), and at any moment, if the Cost of any motion vector predictor is less than certain threshold, then the search may stop and goto step 7. 3. Perform 1 iteration of Directional Small Diamond Search around currentMV. The concept of a Directional Small Diamond Search is explained below. 4. If the smallest Cost is less than a threshold T2, stop the search and goto step 7. Otherwise, choose the motion vector with the smallest Cost as currentMV and goto the next step. 5. If (currentMV=medianMV) and the current smallest Cost is less than a threshold T3, perform Small Diamond Search and go to step 7. 6. If the video is not interlaced, perform Large Diamond Search, as shown in FIG. 3( a ); otherwise, perform Modified Large Diamond Search as shown in FIG. 3( b ). In each of these steps the Cost function is evaluated for each of the marked points of the Diamond. 7. Select the MV with smallest Cost.
In our experiments, a value for w of about 0.8 was found to be effective.
The steps of the Directional Small Diamond Search are now explained. Suppose that centerMV is the current search center and MV1, MV2, MV3 and MV4 are four surrounding search points as shown in FIG. 4 . Compute R(MVi−medianMV) for each MVi. If R(MVi−medianMV)<R(centerMV−medianMV), then compute the SAD and the Cost for MVi. Otherwise, ignore the MVi. Select the MV with the lowest Cost as the currentMV. Note that the concept of a directional diamond search is believed to be new, and constitutes an independent aspect of the invention, which need not be performed in combination with the concept of using a futureMV.
The steps of a Large Diamond Search and Modified Large Diamond Search are the same, but the search is done for all the set of points shown respectively in FIGS. 3( a ) and 3 ( b ).
We now consider a number of possible variations to the embodiment within the scope of the invention.
Firstly, note that the weighting factor w in the Cost function can be different for different blocks. Furthermore, optionally the w may be different for different MV candidates. In particular, the definition of w may depend on situations such as whether the MV candidate is close to the medianMV and/or the futureMV, or whether the x-component or y-component of the MV candidate is the same as the x-component or y-component of the FmedianMV.
Furthermore, the Cost function may not be restricted to the form of Eqn. (6). It can be any function which includes a distortion measurement term (e.g. SAD, sum of square distortion (SSD), mean absolute distortion (MAD), MSD, etc) and a term which takes into account the bits required to encode the motion vector of the current block and those of some neighboring blocks (e.g. the right block, the bottom block, the bottom left block, etc).
Furthermore, in step 1, the definition of futureMV is not restricted to the form given in step 1 above. Two possible alternative definitions for futureMV are:
futureMV≡median(leftMV,TopRightMV,TopRightRightMV)
futureMV≡median(medianMV,TopRightMV,TopRightRightMV)
Furthermore, in step 1 as expressed above, pastMV is selected as the one out of a list collection of possible MVs (preMV and preBottomRightMV) in the previous frame which is farthest from medianMV. However, the list of MV to be considered can contain more than two possibles MV (e.g. preMV, preLeftMV, preRightMV, preTopMV, preTopLeftMV, preTopRightMV, preBottomMB, preBottomLeftMV, preBottomRightMV, etc). In addition, MV from more than one previously encoded frame can be included in the list (e.g. if current frame is frame N, the list can contain frame N-1, N-2, N-3, . . . ). If the current frame is a B-frame, the list of previously encoded frames can include future P-frames.
Furthermore, in step 1, pastMV is chosen to be the possible MV that is farthest from a reference MV (medianMV in step 1). Other reference MVs are possible, including the leftMV, or TopMV, or TopRightMV, or some combination. Other ways of choosing from the list of possible MV are also possible.
In step 2, the Cost of the 3 motion vector predictors are derived in some predefined order. Possible predefined orders include
a) medianMV, followed by futureMV, followed by pastMV b) medianMV, followed by pastMV, followed by futureMV c) futureMV, followed by medianMV, followed by pastMV d) futureMV, followed by pastMV, followed by medianMV e) pastMV, followed by medianMV, followed by futureMV f) pastMV, followed by futureMV, followed by medianMV
Furthermore, while one iteration of the Directional Small Diamond Search is performed in step 3 as expressed above, more than one iteration can be applied.
Simulation Results
We now present simulation results for the embodiment E-PMVFAST. The embodiment was embedded into H.264 reference software JM9.3 [13], and simulated using various QP, video sequence, resolution, and search range. Tables 1 (a-c) and 2 (a-c) show some typical simulation results. The PSNR (peak-signal-to-noise ratio) change and BR (bit-rate) change are the changes of PSNR and bit rate with respect to full search (FS). The simulation results suggest that the bit rate and PSNR of the proposed E-PMVFAST tend to be similar to that of full search and PMVFAST but E-PMVFAST tends to be about 40% faster than PMVFAST, across a wide range of video sequences and bit rates. One important feature of E-PMVFAST is that its motion vector field tends to be very smooth, so that the motion vectors can represent the objects' movement more accurately than other fast motion estimation algorithms.
In each of FIGS. 5( a ) and 5 ( b ), the left-hand image shows (as the short lines) the motion vector fields obtained by the PMVFAST algorithm, and the right-hand image shows the motions vectors for the same image obtained by the embodiment. The motion vector field of E-PMVFAST is significantly smoother than that of PMVFAST, especially in the circled regions. The smooth motion field can be very useful for classifying the motion content of a video in perceptual trans-coding, rate control, multiple block size motion estimation, multiple reference frame motion estimation, and so on.
TABLE 1a
Simulation result for foreman CIF sequences.
Foreman CIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
38.61
10457168
−0.01
1.12%
269.90
−0.01
0.73%
345.62
26
37.25
7498832
−0.02
1.13%
259.61
−0.02
1.17%
337.49
28
35.99
5397584
−0.02
1.53%
250.27
−0.03
1.21%
329.79
30
34.64
3504232
−0.02
1.27%
241.91
−0.04
1.20%
326.41
32
33.34
2730064
−0.02
1.19%
235.26
−0.03
1.22%
321.96
34
32.25
2044176
−0.05
1.57%
230.48
−0.05
1.38%
325.01
36
31.07
1529648
−0.07
1.20%
226.76
−0.09
1.28%
325.47
38
29.9
1184744
−0.05
1.76%
223.29
−0.06
0.99%
328.10
40
28.89
960056
−0.09
1.85%
220.98
−0.11
1.09%
334.25
42
27.79
794312
−0.14
1.71%
218.94
−0.16
1.74%
341.62
44
26.7
672224
−0.17
1.58%
217.42
−0.22
0.89%
351.22
Average
−0.06
1.45%
235.89
−0.07
1.17%
333.36
TABLE 1b
Simulation result for Coastguard CFI sequences.
Coastguard CIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
37.32
19901336
0
0.02%
245.39
0
0.02%
328.81
26
35.77
15169632
−0.01
−0.03%
236.12
0
0.01%
319.07
28
34.35
11403728
−0.01
−0.07%
232.24
−0.01
−0.03%
308.17
30
32.8
8097840
0
0.07%
229.89
0
0.04%
301.18
32
31.34
5616880
−0.01
0.23%
228.38
0
−0.04%
296.55
34
30.08
3913296
−0.01
−0.08%
227.20
−0.01
−0.23%
294.13
36
28.75
2546328
−0.02
0.03%.
225.88
−0.01
−0.04%.
292.18
38
27.55
1684056
−0.03
0.48%.
225.13
−0.03
0.35%.
293.95
40
26.55
1172448
−0.04
−0.01%.
224.78
−0.04
0.15%.
299.45
42
25.52
800328
−0.06
0.65%
225.22
−0.06
1.00%.
308.85
44
24.54
572224
−0.07
−0.10%
225.47
−0.06
0.39%
321.38
Average
−0.02
0.11%
229.61
−0.02
0.15%
305.79
TABLE 1c
Simulation result for Hall CIF sequences
Hall CIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
39.63
6954760
−0.01
0.26%
424.55
−0.01
0.18%
700.53
26
38.6
4539912
−0.02
0.17%
397.68
−0.02
0.43%
704.18
28
37.58
2993752
−0.04
0.07%
370.17
−0.04
0.06%
686.71
30
36.36
2021712
−0.04
0.01%
340.96
−0.04
0.18%
674.18
32
35.17
1411344
−0.03
−0.86%
321.03
−0.05
−0.40%
655.08
34
33.94
957600
−0.02
0.40%
301.76
−0.02
0.44%
659.53
36
32.68
677768
−0.04
0.12%
288.55
−0.06
−0.12%
642.68
38
31.4
493168
−0.05
−0.04%
276.97
−0.05
−0.38%
641.42
40
30.05
379240
−0.05
−0.45%
263.07
0
−0.48%
625.73
42
28.67
279008
−0.03
−0.99%
251.93
−0.07
−0.84%
624.02
44
27.68
214544
−0.02
−1.32%
241.90
−0.04
−1.03%
635.41
Average
−0.02
−0.24%
316.23
−0.04
−0.18%
659.04
TABLE 2a
Simulation result for foreman QCIF sequences.
Foreman OCIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
38.32
2816360
0
0.68%
260.10
−0.01
−0.05%
356.91
26
36.85
2122432
−0.02
0.28%
249.94
−0.02
−0.42%
343.24
28
35.47
1615528
−0.01
0.41%
242.29
−0.01
0.09%
329.89
30
34.01
1213792
−0.01
0.44%
235.40
−0.02
0.35%
322.04
32
32.61
918272
−0.04
0.57%
231.38
−0.01
−0.13%
316.56
34
31.39
710976
−0.04
0.65%
228.06
−0.05
0.05%
314.51
36
30.07
536152
−0.1
0.85%
225.33
−0.07
0.60%
311.05
38
28.81
416112
−0.04
0.31%
223.95
−0.1
−0.10%
310.02
40
27.65
328288
−0.08
0.74%
222.89
−0.08
−0.30%
311.37
42
26.5
259936
−0.12
−0.39%
221.19
−0.1
0.47%
315.72
44
25.36
207344
−0.18
1.43%
218.38
−0.25
−0.08%
321.03
Average
−0.06
0.54%
232.63
−0.07
0.04%
322.94
TABLE 2b
Simulation result for Akiyo QCIF sequences.
Akiyo OCIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
40.81
530832
0.01
0.01%
483.45
0.01
0.01%
1143.12
26
39.42
391936
0
−0.38%
428.54
0
−0.38%
1017.49
28
38
289096
0
−0.09%
389.95
−0.01
−0.25%
879.72
30
36.57
208488
−0.01
0.40%
352.74
−0.03
0.33%
779.84
32
35.03
153776
−0.04
0.83%
312.72
−0.02
1.01%
699.16
34
33.66
118440
0.03
−0.05%
287.94
0.02
0.58%
644.63
36
32.27
89056
0.01
1.11%
270.48
0.03
0.88%
621.79
38
31.09
70280
−0.01
−0.01%
254.10
−0.03
−0.31%
598.06
40
30.13
57200
0
0.92%
245.76
−0.06
1.58%
612.01
42
28.77
47648
−0.02
0.22%
241.09
−0.02
0.15%
629.43
44
27.68
40608
0.02
0.55%
240.05
0.01
−0.91%
669.52
Average
0.00
0.32%
318.80
−0.01
0.25%
754.07
TABLE 2c
Simulation result for Coastguard QCIF sequences.
Coastguard QCIF
FS
PMVFAST
E-PMVFAST
QP
PSNR
BR
PSNR Change
BR Change
Speed up
PSNR Change
BR Change
Speed up
24
37
4456208
0
0.15%
251.59
0
0.09%
346.68
26
35.4
3298352
0
0.12%
238.53
0
0.08%
330.67
28
33.92
2386152
−0.01
0.15%
234.60
−0.01
0.24%
316.97
30
32.33
1633736
−0.02
0.06%
232.80
0
0.01%
310.88
32
30.86
1110088
0
0.22%
231.60
0
−0.17%
309.50
34
29.62
770656
−0.01
−0.38%
230.98
−0.01
−0.32%
310.31
36
28.3
511000
−0.02
0.28%
230.30
−0.01
0.50%
312.49
38
27.06
354208
0.02
−0.47%
229.61
0.01
−0.57%
314.41
40
26.08
256480
−0.08
−0.72%
229.39
−0.08
−1.08%
317.67
42
25.02
179528
−0.06
2.16%
228.04
−0.07
0.45%
325.54
44
24
131856
−0.09
−0.05%
227.30
−0.09
0.57%
335.34
Average
−0.02
0.14%
233.16
−0.02
−0.02%
320.95
We now turn to a second embodiment of the invention, which illustrates the second aspect of the invention.
As described above, conventional full integer pixel allows motion vectors to take on location values in each direction of −2.0, −1.0, 0, 1.0, 2.0, etc. In the second embodiment of the invention, the possible location values are selected to be close to the predictor. For the location value which is nearest to 0, we can use (instead of 1.0) another location value such as 0.85 such that the allowable location values would include −2.0, −0.85, 0, 0.85, 2.0, etc. The advantage of this is that statistically motion vectors tend to be close to 0. And thus by choosing the location closer to 0, we would be closer to the true motion vector and thus can give better motion compensation that can lead to higher compression efficiency. Similarly, the other location values can be changed. As an example, the location value of 2.0 can be changed to 1.9 such that the allowable location values would include −1.9, −0.85, 0, 0.85, 1.9, etc. The beauty of the proposed change is that the same motion vector code can be used, except that an encoded motion vector location of 1.0 should be interpreted as 0.85, and 2.0 as 1.9, etc.
Half pixel precision allows motion vector to take on location values such as 0.0, 0.5, 1.0, 1.5, 2.0, etc. We propose to modify these location values, especially those close to the predictor. For the location value of 0.5 that is very close to 0, we propose to use a different value. For example, one possibility is to use 0.4 instead of 0.5. In other words, the location values would include 0.0, 0.4, 1.0, 1.5, 2.0. Similarly, other location values can be modified. For example, the location value of 1.0 can be changed to 0.95 so that the new set of location values would include 0.0, 0.4, 0.95, 1.5, 2.0, etc. Again this can help to increase the compression efficiency. Similarly, the other location values can be modified to increase the compression efficiency. However, changing such locations can lead to significantly higher computation efficiency both at the encoder and the decoder. Usually, most of the compression efficiency gain comes from changing the location values close to the predictor.
Quarter pixel precision allows motion vector to take on location values such as 0.00, 0.25, 0.50, 0.75, 1.00, etc. We can modify the location values, especially those close to the predictor. As an example, we can modify them to be 0.00, 0.20, 0.47, 0.73, 0.99, etc.
Note that the proposed method allows us to choose an arbitrary number N of location values between each integer location values. For example, between the location values of 0 and 1, half-pixel precision uses 1 location value {0.5}, quarter-pixel precision uses 3 location values {0.25, 0.50, 0.75}, and ⅛-pixel precision uses 7 location values (0.125, 0.250, 0.375, 0.500, 0.625, 0.750, 0.875). The proposed method allows us to choose any N location values between 0 and 1. For example, we can choose N=2 values such as 0.3, and 0.6.
The proposed non-uniformed subpixel motion estimation and compensation does not need to be applied to every region of every frame. Instead, some bits can be introduced in the headers to indicate whether it is turned on or off for each region (e.g. slice) of the video frames. Other than that, it can be directly applied to the existing standards without any change in syntax because the same motion vector code can be applied.
The proposed non-uniform subpixel motion estimation and compensation was simulated using H.264 JM82 software and the results are shown in the tables above, in which QP stands for quantization parameter. The simulation used the location values ( . . . −1, −0.75, −0.5, −0.15, 0, 0.15, 0.5, 0.75, 1 . . . ), in both x and y directions. That is, only the location values at −0.25 and +0.25 were modified as compared with the standard scheme using quarter-pixel spaced location values. Apart from using the novel location values, the algorithm otherwise identical to the known H.264 standard algorithm. As indicated in the tables, the second embodiment can achieve considerable reduction in bit rate while achieving similar PSNR. No change in the syntax of H.264 is necessary.
QP = 20
QP = 24
Sequences
JM82
Proposed
Difference
JM82
Proposed
Difference
Akiyo
PSNR
44.11
44.13
0.02
41.73
41.74
0.01
Bitrate
3332792
3140080
−5.78%
1766112
1674296
−5.20%
News
PSNR
42.79
42.83
0.04
40.19
40.22
0.03
Bitrate
6908656
6665160
−3.52%
4156840
4017968
−3.34%
weather
PSNR
43
43.01
0.01
39.57
39.58
0.01
Bitrate
6929368
6803496
−1.82%
4425912
4351312
−1.69%
Sean
PSNR
42.65
42.67
0.02
39.8
39.83
0.03
Bitrate
5009336
4755328
−5.07%
2734592
2585480
−5.45%
QP = 28
QP = 32
Sequences
JM82
Proposed
Difference
JM82
Proposed
Difference
Akiyo
PSNR
39.33
39.34
0.01
36.66
36.69
0.03
Bitrate
927791
904744
−2.48%
491032
497600
1.34%
News
PSNR
37.6
37.62
0.02
34.68
34.68
0
Bitrate
2497384
2441216
−2.25%
1476680
1469640
−0.48%
weather
PSNR
36.29
36.29
0
32.88
32.89
0.01
Bitrate
2745184
2723152
−0.80%
1660648
1665368
0.28%
Sean
PSNR
36.94
36.95
0.01
33.92
33.91
−0.01
Bitrate
1497232
1433544
−4.25%
793552
778816
−1.86%
Although only a few embodiments of the invention are described above, many variations are possible within the scope of the invention.
For example, the description of the invention given above is for blocks of fixed size in P-frames with one reference frame. However, this invention can be applied to blocks with multiple sub-block sizes, and the blocks need not necessarily be non-overlapping. There can be more than one reference frame, and the reference frame(s) can be any block in the past or in the future of the video sequence relative to the current frame.
For the video, one picture element (pixel) may have one or more components such as the luminance component, the red, green, blue (RGB) components, the YUV components, the YCrCb components, the infra-red components, the X-ray or other components. Each component of a picture element is a symbol that can be represented as a number, which may be a natural number, an integer, a real number or even a complex number. In the case of natural numbers, they may be 12-bit, 8-bit, or any other bit resolution. While the pixels in video are 2-dimensional samples with rectangular sampling grid and uniform sampling period, the sampling grid does not need to be rectangular and the sampling period does not need to be uniform.
INDUSTRIAL APPLICABILITY
Each embodiment of the invention is suitable for implementation by fast, low-delay and low cost software and hardware implementation of MPEG-1, MPEG-2, MPEG-4, H.261, H.263, H.264, AVS, or related video coding standards or methods, which may be modified to include it. Possible applications include digital video broadcast (terrestrial, satellite, cable), digital cameras, digital camcorders, digital video recorders, set-top boxes, personal digital assistants (PDA), multimedia-enabled cellular phones (2.5 G, 3 G, and beyond), video conferencing systems, video-on-demand systems, wireless LAN devices, bluetooth applications, web servers, video streaming server in low or high bandwidth applications, video transcoders (converter from one format to another), and other visual communication systems, etc.
REFERENCES
The disclosure of the following references is incorporated herein in its entirety:
[1] Joint Video Team of ITU-T and ISO/IEC JTC 1, “Draft ITU-T Recommendation and Final Draft International Standard of Joint Video Specification (ITU-T Rec. H.264|ISO/IEC 14496-10 AVC),” document JVT - G 050 r 1, May 2003. [2] A. M. Tourapis, O. C. Au, and M. L. Liou, “Predictive Motion Vector Field Adaptive Search Technique (PMVFAST),” in ISO/IEC JTC 1 /SC 29 /WG 11 MPEG 2000, Noordwijkerhout, NL, March'2000. [3] R. Li, B. Zeng, and M. L. Liou, “A new three-step search algorithm for block motion estimation,” IEEE Trans. On Circuits and Systems for Video Technology , vol. 4, no. 4, pp. 438-42, August'94. [4] Z. L. He and M. L. Liou, “A high performance fast search algorithm for block matching motion estimation,” IEEE Trans. on Circuits and Systems for Video Technology , vol. 7, no. 5, pp. 826-8, October'97. [5] A. M. Tourapis, O. C. Au, and M. L. Liou, “Fast Motion Estimation using Circular Zonal Search”, Proc. of SPIE Sym. Of Visual Comm . & Image Processin , vol. 2, pp. 1496-1504, Jan. 25-27, '99. [6] A. M. Tourapis, O. C. Au, M. L. Liou, G. Shen, and I. Ahmad, “Optimizing the Mpeg-4 Encoder—Advanced Diamond Zonal Search”, in Proc. of 2000 IEEE Inter. Sym. on Circuits and Systems , Geneva, Switzerland, May, 2000. [7] K. K. Ma and P. I. Hosur, “Performance Report of Motion Vector Field Adaptive Search Technique (MVFAST),” in ISO/IEC JTC 1 /SC 29 /WG 11 MPEG 99 /m 5851, Noordwijkerhout, NL, March'00. [8] A. M. Tourapis, O. C. Au, and M. L. Liou, “Fast Block-Matching Motion Estimation using Predictive Motion Vector Field Adaptive Search Technique (PMVFAST),” in ISO/IEC/JTC 1 /SC 29 /WG 11 MPEG 2000 /M 5866, Noordwijkerhout, NL, March'00. [9] Implementation Study Group, “Experimental conditions for evaluating encoder motion estimation algorithms,” in ISO/IEC JTC 1 /SC 29 /WG 11 MPEG 99 /n 3141, Hawaii, USA, December'99. [10] “MPEG-4 Optimization Model Version 1.0”, in ISO/IEC JTC 1 /SC 29 /WG 11 MPEG 2000 /N 3324, Noordwijkerhout, NL, March'00. [11] T. Koga, K. Iinuma, A. Hirano, Y. Iijima, and T. Ishiguro, “Motion compensated interframe coding for video conferencing,” Proc. Nat. Telecommun. Conf ., New Orleans, La., pp. G5.3.1-G5.3.5, December'81. [12] J. R. Jain and A. K. Jain, “Displacement measurement and its application in interframe image coding,” IEEE Trans. On Communications , vol. COM-29, pp. 1799-808, December'81. [13] JVT reference software JM9.2 for JVT/H.264 FRext. | Method, systems and software are proposed for obtaining for blocks of a first image similar blocks of a second image (the “reference image”). The blocks of the first image are processed sequentially, for each block trying out a number of candidate locations in the second image and evaluating a cost function for each. Each candidate location in the second image is displaced by a respective motion vector from the block of the first image. In a first aspect of the invention the cost function is a function of a predicted motion vector for future blocks of the first image (i.e. blocks of the first image which have not yet been processed). In a second aspect of the invention the motion vectors are given by location values which are not all whole pixel spacings, halves of the pixel spacing, or quarters of the pixel spacing. | 7 |
BACKGROUND OF THE INVENTION
The present invention refers to a dispensing appliance for at least two components, in particular a compact hand-held appliance, comprising a respective pump assembly for each component, each of the pumps being connected to a detachable container which holds one of the components, and the outlets of the pumps ending in a common outlet. Such an appliance is known from PCT/GB92/00813 (which corresponds to U.S. Pat. No. 5,277,333), which refers primarily to the storage container while the design of the pump assembly is being described quite summarily. U.S. Pat. No. 4,690,306 discloses a method and device for storing, mixing and dispensing of at least two fluid substances, wherein the device is assembled in a sort of frame with relatively complicated pieces and spring means, and the containers are disposable.
SUMMARY OF THE INVENTION
On the base of this prior art, it is the object of the present invention to provide a pump-like dispensing appliance as mentioned above which offers an increased efficiency and is suitable for different types of drives, and which is easy to manufacture as well as, on the other hand, easy to disassemble. This object is attained by means of an appliance wherein the pump assemblies are held in a frame which can be dismantled and reassembled, comprising a respective pump assembly for each component, each of the pumps being connected to a detachable container which holds one of the components, and the outlets of the pumps ending in a common outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail hereinafter with reference to a drawing of embodiments.
FIG. 1 shows a part of the dispensing appliance of the invention with two distinct pump assemblies in a sectional view;
FIGS. 2 and 3 show the assembly of FIG. 1 on an enlarged scale;
FIG. 4 shows an embodiment of the appliance according to the invention in a front view;
FIG. 5 shows the appliance of FIG. 4 in a perspective view;
FIG. 5A shows a detail of an alternative embodiment;
FIG. 6 shows an alternative embodiment in a sectional view according to line VI--VI in FIG. 1;
FIG. 7 shows a pneumatically operated appliance according to FIG. 1 in a sectional view; and
FIG. 8 shows a detail of a dispensing appliance.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 3 and 7 each show two different examples of possible pump assemblies, the remaining component parts being present in all appliances. In a given appliance, the respective pump pistons have equal lengths and strokes; their diameters, however, may be different. Moreover, in FIGS. 1, 2 and 3, respectively, the portion of an appliance on its dispensing side is schematically shown, which is independent from the drive, i.e. the drive shafts of the pump pistons can be driven pneumatically, electrically or manually.
The pump portion comprises a frame 1 which is substantially composed of a front frame plate 2 and a rear frame plate 3 which are connected by several, at least two opposing frame rods 4 which are provided both at the front and at the rear with threaded portions 5 and 6, respectively, to each of which a respective wing nut 7 is screwed at the front and a respective hexagon nut, for example, at the back. Three frame rods may, e.g., be provided, as indicated in schematical FIG. 5. Moreover, other types of adjustable attachments and actuating devices of the frame rods to the frame plates are possible. It should be mentioned that the term "front" refers to the side of common outlet 9 and the term "rear" to the drive side, as far as this application is concerned.
Frame 1 accommodates the two distinct pump assemblies 10 and 11 with pistons of different lengths 12 and 13, in order to show two embodiments in a single figure. The pump assemblies are disposed in a common, twin-cylinder shaped housing 14 to whose front end 14a common outlet 9 is secured. The front part 14b containing front end 14a is advantageously separable from the rest of the housing for facilitating to service the front seals and in particular the front check valves. Secured to pistons 12 and 13 are respective drive shafts 15 and 16 which are connected, as mentioned above, to any kind of drive. The two cylinders 17 and 18 are provided with respective outlets 19 and 20 each of which is sealed by a spring-loaded valve ball 21. The two outlets 19 and 20 remain separated even in common outlet tube 9. The latter can be provided, e.g., with a static mixer 64 which serves the purpose of mixing the media and to start a corresponding reaction, and which is screwed on by means of threaded portion 22 and a union nut 65. When using cylinders of different cross-sections, it is advantageous to provide the two outlet channels 19 and 20 with different cross-sections which are adapted to the piston cross-sections.
In the condition illustrated in FIG. 1, the two pistons are in their rear end positions, and it appears in FIGS. 1 or 3 that between the rear end of the pistons and the closures 23 and 24 of the cylinders, respective compartments 25 and 26 are formed which are designed as leakage compartments in order to collect quantities of material which may possibly leak out if the sealing is imperfect. For adjusting the piston or pistons axially forwards or backwards to assure both pumps commence metering at precisely the same time, the rear end of the piston or pistons may comprise holes around its circumference for an adjustment key. As appears in FIG. 3, in particular, the leakage compartments are not integral with the cylinders but are arranged in a dismountable manner. The leakage compartments are primarily intended to keep any amount of material from passing to the outside and to contaminate the operator or the surroundings. For this purpose it is advantageous if the inside of the leakage compartments is visible from the outside in order to verify their filling levels.
It is more clearly visible in enlarged FIGS. 2 and 3 that the pump cylinders 17 and 18 are not manufactured in one piece but are composed of several cylinder segments between which seals are disposed. When comparing pump assembly 10 to pump assembly 11, it appears that the two assemblies are not identical, thus demonstrating that different alternatives are possible. Cylinder 17 of pump assembly 10 is composed, starting from the outlet end, of a cylinder head piece 27 in which spring-loaded valve ball 21 is disposed and which is provided with outlet 19 and with a seal 28, e.g. an O-ring. Adjoining thereto is a segment 29 which is also provided with a seal 30, e.g. an O-ring. Between the first segment 29 and adjoining segment 31, which is disposed in the area of inlet 32, a lip seal 33 is provided.
A chamber segment 34 follows which, as opposed to the other ones, does not have a solid, level tube wall but is provided with an internal groove 35 which is connected to a distinct container by an inlet 85, see FIG. 8. The groove serves the purpose of wetting the piston with a liquid from the distinct container and to create a liquid barrier in order to prevent any contact of the dispensed component with air in the case that the component is of such a chemical composition as to be sensitive to air or humidity. Moreover, the liquid can serve to prevent hardening of the materials contained in the leakage compartments. It is understood that the wetting liquid will have to be chemically adapted to the dispensed component.
Seals 36 and 37 are disposed on either side of chamber segment 34, seal 37 being followed by another, fourth segment 38. The rear closure 23 of the cylinder follows the fourth segment 38, the closure forming leakage compartment 25.
As will be understood in the discussion of the second pump assembly 11, it is also possible to realize such a pump assembly without a wetting liquid and an internal groove, respectively, if a less sensitive medium is being dispensed.
The construction of second pump assembly 11 is similar to that of the first one and has a first segment 39 with a seal 40, a second segment 41 with a seal 42 between the first and the second segment, as well as a third segment 43 with a seal 44 between the second and the third segment, the third segment 43 being followed by rear cylinder closure 24 which forms leakage compartment 26. In analogy to the first inlet 32, the second pump assembly is also provided with an inlet 45. The two drive shafts 15 and 16 are guided in rear closures 23, 24 of the cylinders by sleeves and in rear end plate 3 where they are sealed by seals 63 and are secured, e.g. detachably screwed, to pistons 12 and 13.
Due to the fact that the pump cylinders are not made in one piece but in the form of segments which are not only provided with seals between them but also around the segments, pistons without seals can be used whose manufacture is thereby simplified and which result in a more efficient sealing in such appliances. For the sealing of the segments between them and with respect to the housing, other seals than the illustrated ones can be used as well.
In FIG. 6, an alternative embodiment of cylinder head piece 83 is illustrated wherein the spring-loaded valve balls 84 are disposed as far upwardly as constructively possible in order to be better able to evacuate the air which accumulates in that area and which results in disturbances in operation.
It follows from the figures that the front frame plate acts upon cylinder head piece 27 by housing closure 14 and rear frame plate 3 acts upon rear closures 23 and 24 of the cylinder, in such a manner that the head piece and the rear closure and thus all the cylinder segments can be tensioned by the wing nuts or the like. This results in a possibility for adjustment and readjustment of the different seals, in particular of those seals whose sealing action is readjustable by the tensioning action.
Thus, the frame and the frame rods with nuts disposed thereon allow an easy dismantling of the pump assemblies, as well as an adjustment or readjustment of the seals.
When using more than one storage container, it is important that the inlet ports of the pump assemblies are as close to each other as possible in order to save space and to obtain short distances, as well as in order to obtain minimal tilting moments. If the inlet port were disposed in parallel to each other and perpendicularly with respect to the longitudinal axis, the two inlet ports and thus the pump cylinders would soon be far apart if storage containers with large diameters are used. According to FIG. 4 or 5, a solution allowing the use of large storage containers while maintaining a short distance between the inlet ports and the pump cylinders consists in disposing the longitudinal axes of the storage containers and thus also of the inlet ports at a certain mutual angle, e.g. at an angle of 20° to 90°, preferably between 20° and 40°. Such an arrangement also allows an attachment of a third storage container between the two others in the case of more than two pump assemblies.
FIG. 4 shows a possible embodiment of a dispensing appliance in a front view. Front frame plate 2 with three frame rods 4 and the corresponding wing nuts 7 as well as outlet 9 are visible. Indicated by dotted lines are the two cylinders 17 and 18 with their respective inlet ports 46 and 47 whose longitudinal axes form an angle of approximately 35°. The inlet ports are designed to receive storage containers 48 and 49 in a detachable manner.
This V-shaped arrangement of the inlet ports 46, 47 with their threads 46a, 47a respectively allows the use of storage containers having a relatively large capacity and diameter and at the same time a minimal distance between the inlet ports, which results in a minimal tilting moment of the drive.
As an alternative, it is possible to dispose the inlet ports at an angle and to provide the inlet ports with bent connecting pieces thus that the storage cylinders are disposed parallel to each other.
In the present example, the inlet ports and the outlets of the storage containers have the same diameters, but it is understood that these diameters can also differ from each other, especially in order to prevent any confusion of the storage containers. The special container for the lubricating liquid is generally disposed behind the two storage containers.
In FIG. 5, the embodiment of a dispensing appliance shown in FIG. 4 is illustrated in a perspective view without the storage containers. Here, a dispensing tube 50 is shown around common outlet 9, which may be connected to a static mixer. FIG. 5 shows further that it is possible to provide the housing with a removable front part 14b comprising the front end 14a and which facilitates to service the front seals and in particular the front check valves 21. It is also shown that this front part 14b may contain air vent screws 90 for closing air vents at the highest points of the cylinders so as to be able to bleed off air within the metering cylinders, check valves, and outlet area.
In FIG. 5A the common, subdivided outlet 50 is provided with a partition wall 50a. It may be advantageous or necessary to provide one or both sides of the outlet nose with additional check valves 50b to stop low viscosity materials from flowing out of the outlet area, or to contain a high ratio liquid within the outlet nose since loss would be critical, or to stop one component from entering back into another outlet area, or as secondary check valves as back up for primary check valves.
In FIG. 5, rear frame plate 3 as well as a drive unit 51 are visible. This appliance further comprises a longitudinally displaceable and lockable suspending device 52 which allows to suspend the appliance in a longitudinally balanced position, resulting in a small tilting moment and good handling thereof. Generally, the appliance is held by handle 78 and actuated by trigger 79. The handle further comprises a control device 89 which works in conjunction with the trigger operation for intermittent metering and mixing as opposed to metering and mixing with automatic reload each time. The control device 89 enables metering pumps to be locked in the forward position thus blanking off pump inlet areas (i.e., blocking the inlet openings) during storage container change over.
As mentioned in the introduction, drive shafts 15 and 16 may be actuated either by an electrically, pneumatically or manually operated drive. It is important for all types of drives that the drive shafts are guided as synchronously and frictionlessly as possible. An example of an electrically operated dispensing appliance is indicated in Swiss patent application no. 02 759/92-4, and a manually operated dispensing appliance e.g. in EP-A-408 494 (which corresponds to U.S. Pat. No. 5,137,181) or in Swiss patent application no. 02 758/92-2 (which corresponds to U.S. Pat. No. 5,392,956).
In all embodiments, the pump pistons are advanced when trigger 79 is actuated and are automatically retracted back to the starting position when the latter is released. Furthermore, it is advantageous to provide that the pistons are capable of being stopped in any given position, whereby an exchange of the storage containers is facilitated, in particular.
In FIG. 7, an example of a pneumatic drive is indicated. Pneumatic drive 53 includes a cylinder 54 which is connected to rear frame plate 3 and comprises an inner, fixed guiding tube 55 which serves both as a guide and at the same time as a supply duct for the compressed gas in order to thrust piston plate 57 forward. The compressed gas passes through the guiding tube, one end of which is embedded in frame plate 3 together with supply duct 56 and the other end of which is embedded by means of a seal 69 in a socket 70 of cylinder bottom 61, and to a rubber-elastic shuttling member 71 which is pushed back under the pressure of the compressed gas and whose lip seal 72 is pressed towards the shuttling member, so that the compressed gas passes through a compartment 73 of the socket and through outlets 74 into the rear cylinder cavity 75 in order to advance the piston plate.
A closure 80 is screwed to socket 70, the closure comprising an end piece 76 with a venting bore 77 and a filter disk 81 which also serves as a sound absorber.
When switching over a non-represented control valve by releasing trigger lever 79, the compressed gas passes through second supply duct 60 into drive cylinder 82 and acts upon the piston plate which returns the pump pistons by means of drive shafts 15 and 16.
Moreover, when trigger lever 79 is released, guiding tube 55 is vented through duct 56, and shuttling member 71 is pushed to its forward position and against guiding tube 55, so that the air contained in rear cylinder cavity 75 is allowed to escape through compartment 73 and venting bore 77.
The two drive shafts 15 and 16 are secured by means of a thread and a nut 67 in a respective passage in piston plate 57 which is provided with a bidirectionally active external seal 58 and with an internal seal 59 as well as with guiding bushings 68. Drive shafts 15 and 16 are sealed in rear frame plate 3 by seals 63 and in piston plate 57 by seals 66. Screwed-on cylinder bottom 61 is provided with a seal 62.
There are applications where a determined, adjustable metering is, advantageous, which is e.g., achieved by a stroke limitation of the pump pistons. In the case of an electric drive, a stroke limitation is relatively easily obtained by virtue of the electric motor drive circuitry, while mechanical means can be provided in the case of a manual drive, the means being adjustable from the outside and acting upon the pump piston stroke to limit the same.
In FIGS. 5 and 8, adjusting means for the pneumatically operated appliance according to FIG. 7, are indicated, only a section of the appliance being illustrated in the present figure. Rear frame plate 3 with schematically indicated pneumatic drive 53 as well as handle 78 including trigger 79 are visible. Pump assembly 11 has been deleted, so that only pump assembly 10 remains visible in housing 14. In this embodiment, only two frame rods 4 are provided, for example one above the other, vertically. Moreover, inlet 85 for the distinct lubricating liquid container and inlet 47 for storage container 49 are represented.
In the present case, the adjusting means consist of a bar 86 which is secured in piston plate 57 of the drive cylinder and positioned as close as possible to the upper frame rod 4, and of an adjustable length stop 87 which is positioned on the upper frame rod 4. Bar 86 is sealed within rear frame plate 3. Other adjusting means are possible, however, as well as a scale in order to display different dispensing volumes. | The dispensing appliance for at least two components comprises a respective pump assembly for each component, each of said pumps being connected to a detachable container holding one of said components, and the pump outlets ending in a common but divorced outlet. Said pump assemblies are held in a frame which can be dismantled and reassembled, and the cylinders of said pump assemblies are composed of different segments.
Such an appliance is compact and allows an easy change of metering ratios, simplified manufacture and cleaning. | 1 |
RELATED APPLICATION
This application is a divisional of Ser. No. 10/651,141, filed Aug. 28, 2003, now U.S. Pat. No. 6,893,814 issued May 17, 2005 by Swanson et al. which is a divisional of Ser. No. 09/699,225, filed Oct. 27, 2000 now U.S. Pat. No. 6,627,396 issued Sep. 30, 2003 by Swanson et al.
BENEFIT OF PRIOR APPLICATION
This application claims the benefit of the filing date of U.S. Provisional Application 60/162,427, filed Oct. 28, 1999.
FIELD OF THE INVENTION
The present invention relates to a diagnostic sensor for the detection of influenza virus and to a method of detecting influenza virus with such a diagnostic sensor. This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
The early diagnosis of influenza infection is important for several reasons. One reason is that it is critical to be able to rapidly screen influenza from other infectious diseases in the event of a bio-agent attack. Most scenarios for bio-agent attacks show a slowed response to the recognition that an attack has taken place primarily because diseases such as anthrax and smallpox present flu-like symptoms. Medical personnel do not have a rapid and simple screen for influenza infection and, consequently, victims can be miss-diagnosed as having the flu and sent home. A delay of even a few days in the recognition of a bio-agent attack can have adverse affect on the minimization of the impact of an attack.
Another reason for a rapid diagnostic for influenza is important is in helping to avert a worldwide pandemic in the event that a new strain like the 1918 swine flu appears. Rapid screening with inexpensive fieldable sensors is essential to rapidly pinpoint a new potential outbreak. Although it is also important to specify the strain of the influenza infection, it is first critical to rapidly identify an outbreak and this can only be done using a flexible, inexpensive, fieldable sensor.
Recently, a number of high binding affinity neuraminidase (also known as sialidase) inhibitors have been developed and shown to be quite effective in curing the flu but only if such inhibitors are administered early on in the infection (generally within the first 24 to 48 hours). At present, these drugs can not be effectively used as there is not a simple diagnostic tool that can be used to detect the influenza virus early enough to effectively use neuraminidase inhibitors. The only technologies currently capable of early diagnosis of influenza are lab-based approaches like ELISA, which are instrument and personnel intensive, expensive, and slow. What is needed is a simple inexpensive diagnosis that can be easily used in either a clinical or field setting and yet have at least the same specificity and sensitivity as ELISA. Accordingly, it is highly desirable to develop a rapid diagnosis for influenza to facilitate the treatment of influenza using such neuraminidase inhibitors.
An optical biosensor system has recently been developed to rapidly detect protein toxins, e.g., cholera, shiga, and ricin (see, U.S. patent application Ser. No. 09/338,457, by Song et al., filed Jun. 22, 1999). The integrated optical biosensor developed for the detection of protein toxins was based on proximity-based fluorescence changes that are triggered by protein-receptor binding. In demonstrations of this approach for the detection of cholera and avidin using flow cytometry, it was shown that this technique was as sensitive as ELISA. In contrast to ELISA, such an optical biosensor can be much faster (minutes), simpler (a single step with no added reagents) and robust owing to the stability of the recognition molecules (glycolipids and biotin) and membranes. More recently, an optical biosensor system has been incorporated into planar optical waveguides (see, U.S. Provisional Patent Application Ser. No. 60/140,718, by Kelly et al., filed Jun. 22, 1999) and shown to have sensitivity equivalent to that of flow cytometry. The demonstration of such an optical biosensor using planar optical waveguides provides a path towards the development of miniaturized sensor arrays.
One object of the present invention is adaptation of such a biosensor to sensing applications directed to the detection of influenza virus.
Another object of the present invention is the selection and chemical modification of receptors that bind neuraminidase and that allow attachment of such receptors to membranes together with the incorporation of fluorophores.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides for the detection of tetrameric neuraminidase within a sample, where a positive detection indicates the presence of a target virus within said sample, said sensor including a surface, recognition molecules situated movably at said surface, said recognition molecules capable of binding with said tetrameric multivalent neuraminidase, said recognition molecules further characterized as including a fluorescence label thereon, and, a means for measuring a change in fluorescent properties in response to binding between multiple recognition molecules and said tetrameric neuraminidase.
The present invention further provides a method of method of detecting tetrameric neuraminidase within a sample, where a positive detection indicates the presence of a target virus within said sample, said method including contacting a sample with a sensor including a surface, recognition molecules situated movably upon said surface, said recognition molecules capable of binding with said tetrameric multivalent neuraminidase wherein said recognition molecules include a fluorescence label thereon, and measuring a change in fluorescent properties in response to binding between multiple recognition molecules and said tetrameric neuraminidase.
The present invention further provides for the detection of tetrameric neuraminidase within a sample, where a positive detection indicates the presence of a target virus within said sample, said sensor including a surface, at least two different recognition molecules situated movably upon said surface, said recognition molecules capable of binding with said tetrameric multivalent neuraminidase wherein at least one recognition molecule includes a fluorescence donor label thereon and at least one recognition molecule includes a fluorescence acceptor label thereon, and, a means for measuring a change in fluorescent properties in response to binding between at least two different multiple recognition molecules and said tetrameric neuraminidase.
The present invention further provides a method of method of detecting tetrameric neuraminidase within a sample, where a positive detection indicates the presence of a target virus within said sample, said method including contacting a sample with a sensor including a surface, at least two different recognition molecules situated movably upon said surface, said recognition molecules capable of binding with said tetrameric multivalent neuraminidase wherein at least one recognition molecule includes a fluorescence donor label thereon and at least one recognition molecule includes a fluorescence acceptor label thereon, and measuring a change in fluorescent properties in response to binding between multiple recognition molecules and said tetrameric neuraminidase.
The present invention still further provides a trifunctional composition of matter including a trifunctional linker moiety including as groups bonded thereto (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, said recognition moiety capable of binding with tetrameric multivalent neuraminidase.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagram of an exemplary receptor molecule including the three necessary functionalites.
FIG. 2 shows a diagram of another exemplary receptor molecule including the three necessary functionalites.
DETAILED DESCRIPTION
The present invention concerns a diagnostic sensor for the detection of influenza virus and to a method of detecting influenza virus with such a diagnostic sensor. In particular, the present invention concerns a diagnostic sensor capable of detecting organisms such as influenza virus that contain neuraminidase.
Organisms that contain neuraminidase include bacteria ( Vibrio cholerae, Clostridium perfringens, Streptococcus pneumoniae , and Arthrobacter sialophilus ) and viruses (influenza virus, parainfluenza virus, mumps virus, Newcastle disease virus, fowl plague virus, and sendai virus). In viruses, neuraminidase occurs as a tetrameric. This tetrameric structure facilitates the operation of the sensor of the present invention. Detection of neuraminidase activity related to any tetrameric neuraminidase structure in a virus is within the scope of the present invention. Detection of neuraminidase from influenza virus is particularly desired.
The selection of receptors is related to the prior work that has been done to synthesize neuraminidase inhibitors having high binding affinities. In principal, any neuraminidase inhibitor could be used but preferably the present influenza sensor will incorporate those neuraminidase inhibitors that have the highest binding affinities. Typically, neuraminidase inhibitor compositions having in vitro K i (inhibitory constants) of less than about 5×10 −6 M, typically less than about 5×10 −7 M and preferably less than about 5×10 −8 M are excellent candidates for the recognition portion of the influenza sensor of the present invention.
In one embodiment, the influenza sensor of the present invention involves: 1) formation of a biomimetic membrane, which incorporates fluorescent dye-labeled receptors for neuraminidase, on the surface of an optical transducer (this could be a glass bead for flow cytometry-FCM—or a planar optical waveguide for an integrated optical biosensor); 2) the chemical modification of selected neuraminidase inhibitors to attach them to a membrane and to also attach fluorophores that fold into the fluid upper leaf of the membrane; 3) the detection, using a planar optical waveguide of a microsensor array or FCM, of envelope proteins or the influenza viral particle directly as measured by a shift in the ratios of intensity of two individual fluorescently-emitted signals, and 4) the use of multiple receptors in the recognition effect (in influenza neuraminidase is a tetramer) to insure extremely high effective binding affinities (avidity) and, as a result, ultrahigh sensitivities and specificities.
One advantage of the present invention is the ultrahigh sensitivity and specificity obtained by using multiple receptors each with high binding affinities (the avidity effect) to help insure early diagnosis, e.g., within the first 12 hours after infection. Another advantage of the present invention is the simplicity and speed of operation which makes detection fast and operation possible in a variety of situations. Another advantage of the present invention is the elimination of the need for additional reagents or additives thereby simplifying the use and extending shelf storage lifetimes. Another advantage of the present invention is the flexibility in adaptation to either flow cytometry or to miniaturized sensor systems utilizing planar optical waveguide permits use in a variety of clinical or field situations. Another advantage of the present invention is the robustness of the sensor system that results from the high stability of the receptor molecules and the active membrane. Another advantage of the present invention is the simplicity of sample introduction which minimizes front-end sample preparation.
Coupling recognition to signal transduction and amplification can be conducted as follows. The sensor of the present invention mimics many cell signaling processes in nature by directly coupling a recognition event to signal transduction and amplification. In the case of the present influenza sensor, the sensor relies on recognition of chemically modified sialic acid-like receptors by neuraminidase, an envelope protein for influenza. As neuraminidase in a virus such as influenza is a multivalent protein (neuraminidase is a tetramer), binding will bring several receptors into close proximity thereby triggering proximity based fluorescence changes. The selection of target receptors is discussed below. The receptor molecules are chemically modified to both attach fluorescent tags and to attach them to the fluid upper leaf of a phospholipid bilayer. The choice of a phospholipid bilayer is important for several reasons. First, this is an excellent mimic of a cell membrane surface, which is the natural target of envelope viruses. Second, the use of membrane mimics helps minimize non-specific protein absorption and the attendant nonspecific response of the sensor element. Third, the upper leaf of the membrane is fluid thereby insuring that the receptor molecules and their fluorescent tags are mobile and, if the concentration is low, relatively distant thereby minimizing proximity based fluorescence changes prior to protein binding. The binding event between neuraminidase and the sialic acid-like receptors then brings multiple receptors into close proximity triggering the fluorescence changes. There are two proximity based fluorescence changes that can be used for detection. The simplest is self-quenching of fluorescence that results in a sharp decrease in the fluorescence of the fluorophore attached to the receptor molecules. The second is resonant energy transfer (FRET) where donor fluorophores transfer their energy to the acceptor fluorophores that are attached to the receptor molecules. In this case, the receptor molecules are tagged with both fluorescent donors and acceptors (typically in a 1:1 ratio). FRET results in a color change in the fluorescence, which can be more easily distinguished from simple self-quenching in terms of being directly coupled to the receptor-protein recognition. Preferably, the selection of fluorophores is such that there must be overlap of the donor emission with the excitation profile of the acceptor. Many pairs of fluorophores exhibit this relationship and the selection is primarily dictated by the stability of the fluorophores and the most effective separation of the emission profiles to minimize background fluorescence.
Influenza is an RNA virus and, therefore, has a rapid antigenic drift and antigenic shift. As a result, the binding of antibodies and receptor molecules to neuraminidase is constantly changing even within a particular strain. However, antigenic shift and drift do not affect binding of a neuraminidase inhibitor which bind to silacic acid. For this reason, the present invention has targeted the binding region of neuraminidase that targets sialic acid residues on the cell membrane surface. It is through neuraminidase binding to sialic acid that the influenza virus particle invades the host cell through membrane fusion. As this binding event is critical to viral particle invasion, it is likely that the binding pocket in neuraminidase that selects sialic acid is relatively invariant. There have been several crystal structures of neuraminidase measured with differing inhibitors (molecules that mimic sialic acid but which have even higher binding affinities to neuraminidase) that show the binding pocket for sialic acid site is relatively invariant. Moreover, there has been a great deal of work in synthesizing neuraminidase inhibitors that have exceptionally high binding affinities and these molecules are all good potential receptors for the influenza sensor of the present invention. As noted below, initial selection was of a few molecules that have binding affinities in the micromolar range. The use of molecules that target the sialic acid binding site insures that this sensor will be effective over a long period of time and to virtually any strain of influenza. Moreover, as neuraminidase is multivalent with regard to binding sialic acid, the use of inhibitors and sialic acid variants insures that the above sensor transduction scheme (proximity based fluorescence changes) can work and, equally important, that the effective binding affinities are high by virtue of the avidity effect.
Chemical modification of the neuraminidase receptors can be as follows. A number of neuraminidase inhibitors derived from 3,4-diamino benzoic acid have been described in the literature. These compounds bind to the sialic acid binding site on neuraminidase. One of these 3,4-diamino benzoic acid-based neuraminidase inhibitors, 4-acetylamino-3-guanidine benzoic acid is reported to bind NA with an affinity constant of 10 5 . The present approach to a neuraminidase detector involves covalently linking this inhibitor to a fluorescent molecule that is anchored into a membrane. The covalent attachment is accomplished as follows. 3,4-Diamino benzoic acid (I) is acetylated on the 4-amino group to yield 3-amino-4-acetylamino benzoic acid (II). Compound II is then alkylated to yield 3-alkylamino-4-acetylamino benzoic acid (III). Treatment of III with cyanogen bromide followed by ammonia yield compound IV that may serve as a neuraminidase receptor in the present invention.
The neuraminidase receptor (IV) can be linked to the fluorescent probe a number of ways. One possible approach is as follows. First compound IV is attached to a polyethylene glycol spacer to the alpha-amino group of lysine. The alpha-carboxyate is modified as an amide to a 16, 17, or 18-carbon hydrocarbon, which serves as a membrane anchor. The ε-amino group of lysine is modified to carry a hydrophobic fluorescent molecule such as a Bodipy molecule.
Preparation of the Membrane Architectures on Optical Transducers can be as follows. As noted above, the receptor molecules would have been chemically modified to bind them into the upper leaf of a phopholipid bilayer through attachment to two aliphatic side chains. Moreover, the fluorophore has been selected and attached in a way that insures that it folds over into the upper leaf of the bilayer. The fact that the fluorophore resides in the upper leaf of the bilayer is important for two reasons. First, this insures that the fluorophore itself and the linker that attaches it to the lipid tail do not interfere with recognition by providing a non-specific site for protein binding. Second, the residence of the fluorophore in the upper leaf provides additional stability of the receptor-membrane structure. The membranes are then fabricated onto optical transducers (either glass beads for FCM or planar optical waveguides for microsensor arrays) by vesicle fusion onto hydrophobic or hydrophilic surfaces. The simplest approach is vesicle fusion onto a hydrophilic surface to form a support bilayer. This can be done in a flow cell where the surface can be exposed for a period of time (hours) to a solution containing the vesicles. The second approach is to spread vesicles containing the tagged receptors over a methyl terminated self-assembled monolayer to form a hybrid bilayer where the lower leaf is covalently attached to the transducer surface. The hybrid bilayer has the advantage of better long-term stability.
In the present invention, the architecture of the fluid membranes can be as a regular bilayer membrane where both layers are deposited upon a support surface, can be a hybrid bilayer, e.g., where a first layer is covalently attached to an oxide surface, can be a selectively tethered bilayer on an oxide surface, where a membrane molecule is covalently bonded to the oxide substrate, or a bilayer cushioned by a polymer film. Supported membranes useful in the practice of the present invention are generally described by Sackmann, in “Supported Membranes: Scientific and Practical Applications”, Science, vol. 271, no. 5245, pp. 43–45, Jan. 5, 1996. Hybrid bilayer membranes or selectively tethered bilayer membranes may be more preferred as such membranes may have greater stability over time and therefor provide greater shelf lifetimes for sensor applications. Additionally, a surface with mobile receptors such as an oxide surface with mobile receptor molecules thereon can serve as a platform in the present invention.
Bilayer membranes can be formed upon a planar oxide substrate, e.g., by initially forming vesicles followed by vesicle fusion or spreading of, e.g., phospholipid, bilayers on glass substrates as is well known to those skilled in the art.
In one embodiment of the present invention, the transduction element used is fluorescein, which has a high extinction coefficient, a high fluorescence quantum yield and proximity-dependent fluorescence self-quenching. Other suitable fluorescent dyes are well known to those of skill in the art. Fluorescein may be covalently attached to a free functional group by appropriate coupling to produce a fluorescein-labeled moiety. The fluorescein should have minimal influence on the binding affinity of the recognition portion of the final molecule to the influenza virus.
In another embodiment of the present influenza sensor, the sensing molecules can be functionalized with either an acceptor dye molecule or a donor dye molecule whose excitation spectra overlap for efficient energy transfer. In effect, excitation of a blue emitting dye can result in fluorescence with a maximum at roughly 570 nm when functionalized Bodipy is free to move about in the bilayer membrane. Upon exposure to influenza virus (tetrameric neuraminidase), both the donor and the acceptor dyes are brought into close proximity. This can result in an energy transfer and a decrease in the fluorescence at 570 nm and a concomitant increase in the fluorescence of the acceptor dye that has its fluorescence maximum at roughly 630 nm. Such a simultaneous increase in the red fluorescence and decrease in the blue fluorescence is a highly distinguishing feature of this sensor approach. In effect, a two-color fluorescence measurement can be used to probe the intensity of fluorescence from both dye molecules. Only a specific binding event between the neuraminidase and the receptor will give rise to such a simultaneous increase in one fluorescent signal with a decrease in the other. Any change in the environment will give rise to shifts of the fluorescence of both dye molecules. Such an energy transfer approach provides a means for self-referencing in such sensor applications.
A number of exemplary methods for the preparation of the compositions of the invention are provided below. These methods are intended to illustrate the nature of such preparations are not intended to limit the scope of applicable methods.
Generally, the reaction conditions such as temperature, reaction time, solvents, workup procedures, and the like, will be those common in the art for the particular reaction to be performed. The cited reference material, together with material cited therein, contains detailed descriptions of such conditions. Typically the temperatures will be −100° C. to 200° C., solvents will be aprotic or protic, and reaction times will be 10 seconds to 10 days. Workup typically consists of quenching any unreacted reagents followed by partition between a water/organic layer system (extraction) and separating the layer containing the product.
Oxidation and reduction reactions are typically carried out at temperatures near room temperature (about 20° C.), although for metal hydride reductions frequently the temperature is reduced to 0° C. to −100° C., solvents are typically aprotic for reductions and may be either protic or aprotic for oxidations. Reaction times are adjusted to achieve desired conversions.
Condensation reactions are typically carried out at temperatures near room temperature, although for non-equilibrating, kinetically controlled condensations reduced temperatures (0° C. to −100° C.) are also common. Solvents can be either protic (common in equilibrating reactions) or aprotic (common in kinetically controlled reactions).
Standard synthetic techniques such as azeotropic removal of reaction by-products and use of anhydrous reaction conditions (e.g. inert gas environments) are common in the art and will be applied when applicable.
As discussed in this application, in a preferred embodiment the signal transduction scheme is dependent of FRET. To be detected, influenza virus particles (neuraminidase tetramers) must bind two or more receptor molecules. Binding must cause the receptors to aggregate resulting in fluorescence energy transfer. These “receptor molecules” have three functions. First they must have a recognition ligand that binds specifically to an agent. The receptor must carry the fluorescent reporter and must be mobile in a lipid bilayer membrane. Diagrammed in FIG. 1 is a prototype “receptor”. A trifunctional linker molecule must connect the recognition site, fluorescent reporter, and membrane anchor.
Trifunctional Linker—Because they are available, α-amino acids with functional groups on the side chains are good candidates as trifunctional linkers. In addition to the α-amino and α-carboxyl functional groups, common amino acids are available with hydroxyl (serine), carboxyl (glutamate and aspartate), thiol (cysteine) and amino (lysine) functionality in the side chain. Lysine derivatives are available with the α-amino and ε-amino groups differentially blocked so their chemistry is orthoganal. Influenza receptors are prepared from commercial N α -benzyloxycarbonyl-N ε -butyloxycarbonyl-L-lysine N-hydroxysuccinimide ester (1, Z-Lys(Boc)-Osu). The N α - and N ε -blocking groups are removed differentially by hydrogenation (CBZ) or dilute acid hydrolysis (Boc). The alkyl anchors are added first by displacement of the N-hydroxy-succinimide ester by treatment of Z-Lys(Boc)-Osu with distearylamine (2, Scheme 1). Next the CBZ group is removed by hydrogenation under standard conditions. Dialkyl-substituted amide (4) have been prepared in essentially quantitative yield as the starting material for the synthesis of the artificial influenza receptors described here. Recognition ligand is attached through a spacer to the α-amino group. Next the Boc protecting group is removed and the fluorescent probe attached to the ε-amino group.
The neuraminidase in influenza virus is uniquely a homotetrameric protein. An active site-specific binder of neuraminidase would provide a flu-specific detector using the FRET scheme. Each viral particle contains several hundred copies of the neuraminidase tetramer. In addition, many competitive inhibitors of flu neuraminidase have been developed as anti-viral agents. These inhibitors provide a specific probe for the active site of neuraminidase. One example, 4-acetylamino-3-guanidino benzoic acid (11) binds flu neuraminidase with a 10 micromolar (μm) affinity constant (Sudbeck et. al., Journal of Molecular Biology, vol. 267, pp. 584–594 (1997)). Derivatives of these compounds have been prepared that will be linked to the receptor through either 4-amino function or the 3-guanidino group. Other nmolar inhibitors are also becoming available from the pharmaceutical industry.
Among the numerous neuraminidase inhibitors taught by the prior art are thoose compounds described by Luo et al., in U.S. Pat. No. 5,453,533, by Bischofberger et al., in U.S. Pat. No. 5,763,483, by Bischofberger et al., in U.S. Pat. No. 5,952,375, Bischofberger et al., in U.S. Pat. No. 5,958,973, Kim et al., in U.S. Pat. No. 5,512,596, Kent et al., in U.S. Pat. No. 5,886,213, Babu et al., in U.S. Pat. No. 5,602,277, by von Izstein et al., in U.S. Pat. No. 5,360,817, Lew et al., in U.S. Pat. No. 5,866,601, by Babu et al., in WO97/47194A1, by Babu et al., in WO99/33781A1, and by Brouillette et al., in WO99/14191A1. Each of these various neuraminidase inhibitors may be structurally incorporated into the influenza sensor of the present invention. The various neuraminidase inhibitors taught by these enumerated patents are incorporated herein by reference.
Many of the neuraminidase inhibitors having the highest binding affinities include at least one functionality from among carboxylate, guanidinium and N-acetyl groups.
Scheme 2 shows the synthesis of the neuraminidase ligand linked via the guanidino group. Commercially available 4-amino benzoic acid (5) is converted to its methyl ester (6) by treatment with methanol/HCl. Such a methylation is described by Haslam, Tetrahedron, 1980, 36, 2409. Methyl 4-amino benzoic acid (6) is treated with acetic anhydride to yield methyl 4-acetylamino benzoic acid (7). Such a treatment is described by Greene, T. W., “Protective Groups in Organic Synthesis” (John Wiley & Sons, New York, 198.1), in particular at pages 251–252. Treatment of (7) with one equivalent of nitronium tetrafluoroborate in methylene chloride yields methyl 3-nitro-4-acetylamino benzoic acid (8). Such a treatment is described by Ottoni et al., Tetrahedron Lett. (1999), 40(6), 1117. Hydrogenation of (8) over Pd/C in ethanol yields the methyl 3-amino-4-acetylamino benzoic acid (9). Such a hydrogenation is described by Entwistle et al., J. Chem. Soc., Perkin Trans 1, 1977, 433. Product 9 is alkylated with one equivalent of a spacer molecule where n is generally from about 2 to about 6. Such a alklyation is described by Onaka et al., Chem. Lett., 1982, 11, 1783. The secondary amine is then converted to the guanidino function by treatment with cyanogen bromide followed by ammonia yielding compound 11. Such a conversion is described by Rai et al., Indian J. Chem., Sect. B, 1976, 14B(5), 376; by Pankratov et al., Izv. Akad. Nauk SSSR, Ser. Khim. 1975, 10, 2198; and by March, “Advanced Organic Chemistry, 4th edition”, (John Wiley & Sons, New York, 1992), in particular at page 903. A fluorescent group is then added to this ligand using the steps below.
The recognition ligand (11) is then attached via the spacer to the lipid anchor as outlined in Scheme 3. The free carboxylate on the spacer of compound 11 is attached to the α-amino group of the lysine linker (4) with dicyclohexyl carbodiimide using standard peptide synthesis conditions to yield (13). Such a process is described by March, “Advanced Organic Chemistry, 4th edition”, (John Wiley & Sons, New York, 1992), in particular at page 420. The methyl ester is saponified from 13 by treatment with lithium hydroxide in THF/water to yield (14). Such a process is described by March, “Advanced Organic Chemistry, 4th edition”, (John Wiley & Sons, New York, 1992), in particular at page 383. Facile removal of the Boc group from (14) with trifluoroacetic acid is required before introduction of the fluorescent group. Such a process is described by March, “Advanced Organic Chemistry, 4th edition”, (John Wiley & Sons, New York, 1992), in particular at page 168. The BODIPY fluorophors are available as their N-hydroxy-succinimide esters. Displacement of the O-Su ester with the α-amino group of the lysine linker will yield the final influenza receptor (Scheme 4).
Scheme 4 shows the synthesis of a neuraminidase ligand linked via the 4-amino group of the 4-acetylamino-3-guanidino benzoic acid-based inhibitors. Methyl 4-amino benzoic acid (6) is used as the starting material. Treatment of 6 with the acyl chloride 16 yields the amide 17. The 3-amino function is added by treatment of 17 with nitronium tetrafluoroborate followed by hydrogenation as described in scheme 2. Conversion of the amino function into a guanidino group is accomplished by treatment with cyanogen bromide followed by ammonia. The terminal hydroxyl on the spacer of compound 20 must be oxidized to a carboxylate for attachment to the lysine linker. The free carboxylate on amino-linked neuraminidase ligand (21) is attached to the α-amino group of the lysine linker (4) with dicyclohexyl carbodiimide as described in scheme 3.
Within the context of the invention samples suspected of containing neuraminidase include natural or man-made materials such as living organisms; tissue or cell cultures; biological samples such as biological material samples (blood, serum, urine, cerebrospinal fluid, tears, sputum, saliva, tissue samples, and the like); laboratory samples; food, water, or air samples; bioproduct samples such as extracts of cells, particularly recombinant cells synthesizing a desired glycoprotein; and the like. Typically the sample will be suspected of containing an organism which produces neuraminidase, frequently a pathogenic organism such as a virus. Samples can be contained in any medium including water and organic solvent/water mixtures. Samples include living organisms such as humans, and man made materials such as cell cultures.
In another embodiment, a varied synthesis of the generic linker molecule can be conducted. As discussed above the signal transduction scheme is dependent on FRET induced by aggregation of two or more fluorescently tagged antibodies bound to a common surface. These “receptor molecules” have three functions. First, they must have a recognition ligand that binds specifically to an agent. For detection of influenza, the recognition ligands can be any neuraminidase inhibitors. In addition, the receptor must carry the fluorescent reporter and must be mobile in a lipid bilayer membrane. Diagrammed in FIG. 2 is a prototype “receptor”. Synthetic schemes to prepare the this receptor are diagrammed in schemes 5–6. A trifunctional linker molecule, homoserine connects the recognition ligand, fluorescent reporter, and membrane anchor. Based on results obtained in developing a cholera sensor, this prototype receptor has the following design characteristics. It has two C-18 alkyl chains needed to tightly anchor the receptor in the membrane. The fluorescent reporters are BODIPY-dyes, which are hydrophobic and tethered to the receptor so as to allow the dye to insert into the lipid bilayer. Insertion into the fluid upper leaf of the bilayer shields the dye molecule from non-specific protein-dye interactions, provides long term stability towards hydrolysis and helps to anchor the antibody to the membrane. The phosphoryl (PEG) n -spacer will partition into the aqueous phase and has been extensively studied for use as in preparing bio-compatible surfaces. PEG is known to minimize non-specific protein-surface interactions.(see literature references 20, 23, 27, 41, and 55–57) The length of the spacer can be adjusted by adding more PEG monomers to optimize fluorescent energy transfer and binding.
The synthesis of the prototype receptor is outlined in detail in schemes 5 and 6. For each step literature references are included and the list of references is below. In addition, yields are included for some steps. Homeserine was chosen as the trifunctional linker because is not subject to—elimination as is serine. Two routes are being explored to link the spacer to homoserine through either a phospodiester or a sulfone. Both of the phosphate and sulfone groups are expected to partition into the aqueous phase. While the phosphodiester linkage is more similar to phospholipids, the potential advantage of the sulfone is its stability to hydrolysis. A common intermediate in both routes is compound IV. Commercially available, N-Fmoc O-Trityl homoserine (I) was coupled to dioctadecylamine (II) using standard peptide coupling conditions to incorporate the membrane anchors (FIG. 2 ).(see literature references 3, 12, 29, and 53) Removal of the trityl-protecting group with trifluoroacetic acid frees the hydroxymethyl group of homoserine (IV) for addition of the spacer.(4-6)
In the phosphodiester route, treatment of homeserine (IV) with (tBuO) 2 P(N(iPr) 2 ) in the presence of
tetrazole follow by deblocking with trifluoroacetic acid gave the phospho homoserine derivative (V) in an overall yield of 73%.(see literature references 33, 37–39, 46, 50, 51, and 54) Standard phosphonate DNA synthesis conditions were used for the condensation of the PEG spacer (VI) with the phospo homoserine (V).(see literature references 9, 10, and 40) Oxidation with t-butyl hodroperoxide yielded the phosphodiester (VII).(see literature references 2, 17, 21, and 43) The intermediate VII has been prepared, purified and characterized by NMR spectroscopy (overall yield 60%). In the sulfone route, conversion the hydroxyl group of homoserine to its corresponding bromide (Va) was achieved in 73% yield by treatment with triphenyl phosphine and carbon tetrabromide.(see literature references 26, 28, and 49) Nucleophilic substitution of bromide by a thiol-terminated PEG spacer (VIa) (18, 48) followed by oxidation will give the sulfone (VIIa).(see literature references 19, 22, 30, 44, and 52).
To complete the linker, the terminal amino group on the PEG spacer is freed, a thiol carboxy, amino, or aldehyde reactive group is added and then the BODIPY dye is added. As diagrammed in scheme 5, this scheme is depicted only for the phopodiester-linked receptor. The identical scheme will be carried out on VIIa to finish the sulfone-linked receptor. First, the BOC-amino protecting group is removed from VII under acidic conditions.(see literature references 4–6) Next reactive group for specific linkage to recognition ligands is added to the PEG-terminal amino group. For example, a thiol specific disulfide(see literature reference 11) or maleimide derivative(see literature reference 32) is added to react with a free thiol on the neuraminidase inhibitor. Similarly, an aldehyde specific hydrazone is added to react with the reducing terminal sugar on a sialaic acid containing oligosaccharide.(see literature references 16, 31, 35, and 36)
These reagents, diagrammed in FIG. 4 , are available as activated N-hydroxysuccinimide esters (Pierce Chemical Co.) (see literature references 1, 7, 45, and 47), which will react directly with the free amino group to form an amide linkage.(see literature references 8, 25, and 34) The BODIPY dye is added in “one pot step” involving removal of the Fmoc group from the homoserine amino group,(see literature references 13–15) which will be modified with the N-hydroxsuccinimide esters of one of the BODIPY dyes.(see literature references 24 and 42) DCC is dicyclohexylcarbodiimide. HOBT is 1-hydroxybenzotriazole. DEAD is diethyl azodicarboxylate. TFA is trifluoroacetic acid.
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Selective oxidation of phenyl sulfides to sulfoxides or sulfones using Oxone and wet alumina. Synlett. 3:235–236. 23.Harder, P., M. Grunze, R. Dahint, G. M. Whitesides, and P. E. Laibinis. 1998. Molecular Conformation in Oligo(ethylene glycol)-Terminated Self-Assembled Monolayers on Gold and Silver Surfaces Determines Their Ability To Resist Protein Adsorption, p. 426–436, J. Phys. Chem. B, vol. 102. 24.Hung, S.C., R. A. Mathies, and A. N. Glazer. 1998. Comparison of Fluorescence Energy Transfer Primers with Different Donor-Acceptor Dye Combinations. Anal. Biochem. 255(32). 25.Jo, S., P. S. Engel, and A. G. Mikos. 2000. Synthesis of poly(ethylene glycol)-tethered poly(propylene fumarate) and its modification with GRGD peptide. Polymer. 41(21):7595–7604. 26.Katritzky, A. R., B. Nowak-Wydra, and C. M. Marson. 1987. The preparation of synunetrical secondary alkyl bromides. Chem. Scr. 27(3):477–478. 27.Kenausis, G. L., J. Voeroes, D. L. Elbert, N. Huang, R. Hofer, L. Ruiz-Taylor, M. 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Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations upon the scope of the invention, except as and to the extent that they are included in the accompanying claims. | A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to freezers for cryogenic treatment of metals and other materials and, more particularly, to a freezer and plant gas system that harnesses the cooling properties of the plant gas evaporator in a manner that facilitates energy and cryogen savings, as well as, thermal processing automation and optimization.
BACKGROUND OF THE INVENTION
[0002] Recently, substantial attention has been drawn to cryogenic treatment of metal parts and tools. The cryogenic treatment process tends to enhance a metal's mechanical properties such as wear resistance, hardness, and dimensional stability. Manufacturing companies, which replace thousands of worn out tools every year at a tremendous cost to the company and the consumer, are turning to cryogenic treatment processes in growing numbers in an effort to increase tool life and reduce costs. Use of the cryogenic treatment process has also found its way into high performance applications and consumer type products. For instance, cryogenic treatment processes are used to enhance the performance and durability of auto racing cars, the accuracy of firearms, the performance of baseball bats and golf clubs, the tonal quality of musical instruments, and the accuracy of aeronautical measuring devices. It also plays an integral part in the construction of satellites, interplanetary probes, and ground and space based telescopes. Other areas in which the cryogenic treatment process is being used include the fields of medicine, genetics, and semiconductors.
[0003] The cryogenic treatment process typically includes the use of liquid cryogen, such as nitrogen or some other inert gas, to significantly cool parts or specimens well below zero degrees Fahrenheit (F); in some instances, all the way down to minus 320° F. The cooling is typically accomplished in a “cold box” or insulated freezer compartment supplied with a liquid cryogen from a liquid storage tank.
[0004] Most facilities with freezer installations also include plant processes, such as heat treating, that utilize inert gas. To supply gas to these processes, evaporators, which enables the liquid cryogen to expand to gas, are installed near the liquid storage tank, usually on the same pad and typically in “free air” to take advantage of maximum heat exchanging properties. A drawback to placing the evaporators in “free air” is that a significant amount of cooling energy is unnecessarily wasted. Harnessing this energy could prove to be advantageous to overall plant processes and economics.
[0005] Another drawback to established freezer installations is the location of the freezer. Typically, the freezer is installed in the immediate vicinity of the liquid storage tank to ensure liquid is available in a reasonable amount of time when called for in the cooling process. This location may be a significant distance from the location most beneficial to the overall process and economics of a plant. For example, in heat treatment facilities, it may be desirable to locate the freezer on the other side of the plant within an automated thermal processing line, which would allow an operator to include heat treatment and cryogenic treatment in the treatment “recipe” for a given part or tool. However, the farther the freezer is located away from the liquid storage tank, the less efficient the freezer system will operate.
[0006] The inefficiency of the freezer system is due to the expansion of the liquid cryogen to gas within the liquid supply conduit. Specifically, the liquid cryogen will expand into gas in the conduit in which it is transported until the conduit itself is cooled below the temperature at which the cryogen will liquefy or stay in liquid form. The farther the freezer is away from the liquid source, the more gas that will evaporate and expand in the conduit and be wasted in the freezer, until the conduit is cooled and liquid reaches the freezer. Because freezer use is intermittent in most freezer installations, the liquid cryogen will typically re-expand along the conduit as the freezer and conduit warm between cooling processes. As a result, significant quantities of gas will likely be wasted upon each use of the freezer.
[0007] One way to combat this waste is to locate the freezer in the immediate vicinity of the liquid storage tank. But as noted above, this requires locating the freezer remotely from the designed heat/cryogenic treatment process and, thus, creates excessive labor costs due to material handling and transportation to and from the balance of the process. Alternatively, a cryogenic pumping system could be used to provide constant pressure to prohibit expansion of the liquid cryogen to gas in the piping system. However, such systems tend to be very costly to purchase and install, as well as, operate and maintain.
[0008] Thus, it would be desirable to provide a freezer and plant gas system in which the freezer can be located remotely from the liquid storage tank, wherein liquid is supplied to the freezer on demand without excessive wasting of gas, and wherein the cooling energy of the plant gas evaporation process can be harnessed.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to an improved freezer and plant gas system that harnesses the cooling properties of the plant gas evaporator to facilitate energy and cryogen savings, as well as the automation and optimization of a plant thermal processing system. In a particularly innovative aspect of the invention, the freezer includes an internally mounted evaporator sized to meet the gas requirements of the plant processes requiring inert gas. By evaporating the plant gas in the freezer, the freezer can be remotely located from the liquid cryogen source while making liquid cryogen available when called for during a cryogenic treatment process of metal and other materials. In addition, by evaporating in the freezer the freezer advantageously harnesses the cooling properties of the evaporator to pre-cool the freezer and material to be treated prior to any use of liquid cryogen in the cooling process; resulting in significant cryogen and energy savings.
[0010] In another innovative aspect of the invention, a liquid load basket is adapted to economically thermally treat materials in a deep cryogenic treatment process.
[0011] Other innovative aspects of the invention include the preceding aspects individually or in combination.
[0012] Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a schematic of the plant gas system of the present invention with an isometric view of a cryogenic freezer of the present invention.
[0014] [0014]FIG. 2 is a piping schematic of the plant gas system of the present invention shown if FIG. 1.
[0015] [0015]FIG. 3 is a graph showing liquid cryogen use of the freezer of present invention plotted against the temperature in degrees F. reach inside the freezer.
[0016] [0016]FIG. 4 is an isometric view of a liquid load basket of the present invention for use in deep cryogenic treatment processes.
[0017] [0017]FIG. 5 is a piping schematic of a prior art freezer installation.
[0018] [0018]FIG. 6 is a piping schematic of an alternative embodiment of the plant gas system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring to FIG. 1, a plant gas system 10 of the present invention is shown. The plant gas system 10 includes a liquid storage tank 20 filled with a liquid cryogen, such as nitrogen, argon, or other liquid cryogen, a freezer 30 with an internally mounted plant gas evaporator 40 , and a plant gas reservoir 50 . In operation, liquid cryogen flows from the storage tank 20 into the freezer 30 to be used in a cryogenic treatment process and separately flows through the evaporator 40 where it is evaporated or expanded into gas. The expanded gas flows into the reservoir 50 and from there it is supplied to plant processes that utilize inert gas. By evaporating inside the freezer 30 , the plant gas system 10 of the present invention advantageously captures the cooling energy of the evaporator 40 that is normally lost in established plant gas methods, and economically and efficiently transports liquid cryogen over long distances.
[0020] Although most thermal processing plants have a sizeable inert gas usage for vacuum furnaces, nitrating furnaces, hardening furnaces, etc., only nominal plant gas usage, such as the introduction of vaporized inert gas into the plant's pneumatic system, is needed to cause liquid cryogen to flow to the plant gas evaporator 40 within the freezer 30 where it is expanded into gas. As a result, liquid cryogen tends to be immediately available when called for in the cooling process. More particularly, liquid cryogen tends to be available without having to expel and, therefore, waste significant quantities of warmer gas as the conduit cools to temperatures necessary to liquefy the cryogen. In addition, the cooling properties of the evaporator 40 advantageously pre-cool the freezer 30 and material to be processed prior to the use of any liquid cryogen. Depending on a plant's gas usage, the freezer and material can be pre-cooled to temperatures ranging from about minus 80° F. to about minus 150° F., and possibly lower. Accordingly, there tends to be substantial savings in the amount of liquid cryogen used during the cooling process. The amount of energy in BTU's that it takes to cool the freezer components and material to a desired temperature illustrates that the pre-cooling process saves a significant amount of liquid cryogen.
[0021] For example, the amount of energy (Q) in BTUs that it takes to cool the a load of material can be calculated as follows:
Q=M×S×DELTA-T
[0022] wherein,
[0023] Q=Heat removed in BTU's
[0024] M=Mass in pounds (#s) of material to be cooled
[0025] S=Specific heat of material in BTU's/#/° F.
[0026] DELTA-T=Temperature differential between ambient temperature, which in heat treating facilities is typically 20° F. higher than outside temperatures, and the temperature to which the internal evaporator will cool the freezer compartment, freezer components, and the material to be processed.
[0027] For this calculation, the material and components to be cooled include a 1,000 # load of steel (S=0.12), a stainless steel (S=0.12) freezer load basket with associated components weighing approximately 180#s, and a stainless steel freezer inner wall assembly weighing approximately 350#s. Assuming an ambient temperature of 80° F., and a pre-cooled temperature of minus 100° F.,
[0028] Delta-T=180° F.
[0029] Q Load =M L ×S L ×Delta-T=1,000×0.12×180=21,600 BTU's
[0030] Q Basket =M B ×S B ×Delta-T=180×0.129×180=3,532 BTU's
[0031] Q wall =M W ×S W ×Delta-T=350×0.129×180=6,867 BTU's
[0032] Q Total =31,999 BTU's
[0033] According to this example, pre-cooling would save the amount of liquid cryogen necessary to generate 32,000 BTU's of cooling energy.
[0034] In addition to these savings, evaporating within the freezer 30 allows the freezer 30 to be located anywhere within the plant and preferably where it would be most beneficial to the overall process. More particularly, the ability to locate the freezer in the area of the plant where the balance of the before-and after-freezing processes are performed, enables a system operator to include freezing in the “recipe” for automated and semi-automated systems. This tends to create considerably savings in time and labor cost due to material handling. For instance, locating the freezer within the balance of heat treating equipment allows the same alloy baskets to be used for the hardening furnace, the washer, the tempering furnace and the freezer. Substantial savings in time and labor cost result from not having to transfer material from one basket to another, and back again, and from not having to transport material from the heat treatment line to the freezer, and back again.
[0035] As noted above, by evaporating in the freezer compartment, liquid cryogen tends to be immediately available at the freezer location. This enables better and more stable control of the temperature in the freezer compartment compared to a system that would first produce warmer gas, then liquid, each time the process calls for cooling. Freezer controls normally include an analogue input temperature control system utilizing a PID (proportional-integral-derivative algorithm) loop to open and close a cryogenic solenoid valve or actuate a motor operated valve (MOV) to control the flow of liquid into the insulated freezer compartment. In previous systems, when the PID control calls for cooling it will first encounter warm gas, then liquid. In response, the PID control is likely to over-react as the higher temperature gas being expelled almost instantaneously turns to the considerably lower temperature liquid. By encountering liquid from the outset, a control system employed with the freezer 30 of the present invention will tend to perform more efficiently and be more stable as the system acquires and maintains a desired temperature set point.
[0036] Referring in detail to FIGS. 1 and 2, the freezer 30 and plant gas system 10 of the present invention comprises a liquid cryogen storage tank 20 having primary 21 and secondary 11 liquid conduit lines extending therefrom. The liquid storage tank 20 stores gases such as nitrogen, argon, oxygen, helium, or others, or combinations thereof, in liquid form. Cryogenic globe valves 12 and 22 are installed along the liquid conduit lines 11 and 21 adjacent the storage tank 20 to isolate the tank 20 while it is being filled, repaired, or replaced. Located adjacent the storage tank 20 along secondary line 11 is a tertiary or backup evaporator 13 , which is normally exposed to ambient conditions as in typical plant gas systems. A secondary plant gas supply line 14 extends from the tertiary evaporator 13 and joins a primary plant gas line 42 , which feeds into a gas reservoir 50 . A dual pressure switch 53 on the reservoir 50 causes a solenoid valve 15 in the secondary plant gas line 14 to open and close depending on the gas pressure in the reservoir 50 . Preferably the solenoid valve will open when the pressure in the reservoir 50 goes below 80 pounds and will close when the pressure in the reservoir 50 raises above 95 pounds. The solenoid valve 15 is preferably a normally open-type solenoid valve to ensure plant processes have sufficient gas in the event of a power outage. A pair of isolation ball valves 16 a and 16 b is located on either side of the solenoid valve 15 to isolate the solenoid valve 15 for repair or replacement. A check valve 19 , preferably a swing back type with a Teflon seat, is located along the secondary gas line 14 after the solenoid valve 15 . The check valve 19 prevents back flow of gas from the primary plant gas line 42 along the secondary the plant gas line 14 toward the liquid storage tank 20 .
[0037] A pressure by-pass line 14 a branches around the solenoid valve 15 and includes a pressure actuated valve 18 and a pair of isolation ball valves 17 a and 17 b located on both sides of the pressure actuated valve 18 . As the gas pressure builds up in the liquid storage tank 20 from the evaporation of the liquid cryogen, a pressure relief valve (not shown) would typically vent the gas from the tank 20 into the atmosphere. The bypass line 14 a and valve 18 combat this wasteful method by advantageously allowing the gas to be flow into the gas reservoir 50 .
[0038] The primary liquid cryogenic supply line 21 extends from the liquid storage tank 20 to a freezer 30 of the present invention. The freezer 30 preferably includes an enclosure 30 a having a door 30 b that is opened to insert material for cryogenic treatment, an internally mounted evaporator 40 , a series of sprayer nozzles 33 , a flapper vent 36 to exhaust gas during the cooling process, and a fan 35 to uniformly circulate the cool gas. The freezer enclosure 30 a , which is generally box-like, preferably includes an external steel plating weldment and an internal stainless steel plating weldment. A load rack formed of three inch stainless steel tubing and rollers is preferably included adjacent the base of the enclosure. A pressure actuated ball-type drain closure is located in the floor of the enclosure to allow liquid to drain after the cooling process. A hydraulic cylinder preferably drives the door 30 b of the enclosure 30 a . Alternatively, the door 30 b could be driven by a pneumatic cylinder or a chain and roller type assembly. The design of the load rack and internal mechanical roller assembly, along with the external features, esthetic, mechanical or otherwise, are such that they can be altered or customized to accommodate different manufacturers preferences and/or requirements.
[0039] Because liquid cryogen flows to the freezer's internal evaporator 40 , where it is evaporated into gas for plant processes, the liquid cryogen is economically and efficiently transported over long distances and still made available for immediate use when called for during the cooling process. As a result, the freezer 30 can advantageously be placed remotely at distances well over 400 feet away from the liquid storage tank 20 . Depending on the gas usage of plant, it may be possible to efficiently operate the freezer/plant gas system with minimal insulation around the liquid cryogenic supply line 21 and still maintain liquid flowing through the supply line 21 to the freezer 30 . However, it may be economically desirable to vacuum jacket the supply line 21 to ensure that the freezer 30 harnesses the maximum amount of available cooling energy.
[0040] The liquid supply line 21 branches off adjacent the freezer 30 to sprayer and evaporator feed lines 21 a and 21 b . Prior to branching off to the separate feed lines 21 a and 21 b , the liquid supply line 21 includes a cryogenic ball valve 24 to isolate the freezer 30 for maintenance, repairs, or replacement. A 350 psi pressure relief valve is preferably located along the liquid supply line 21 between isolation valves 22 and 24 .
[0041] Inside the freezer compartment 30 a , the sprayer feed line 21 a branches into two sprayer feed arms 31 and 32 . A series of spiral cone type spray nozzles 33 are connected to the feed arms 31 and 32 . The feed arms 31 and 32 and sprayer nozzles 33 are mounted along with the fan 35 adjacent the ceiling of the freezer compartment 30 a . As liquid cryogen is sprayed from the nozzles 33 , the fan 35 is operated to uniformly circulate cool gas around the material being treated. Prior to entering the freezer compartment 30 a , the sprayer feed line 21 a includes a cryogenic ball valve 25 , a pressure regulator 27 , which prevents the freezer compartment 30 a from becoming over pressurized during the cooling process, a solenoid valve 29 , which controls the flow of liquid cryogen to the spray nozzles 33 located on feed arms 31 and 32 , and a pair of pressure (350 psi) relief valves 26 and 28 preferably located between the isolation valve 25 , the pressure regulator 27 and the solenoid valve 29 . The freezer 30 preferably includes an analogue input temperature control system with a PID loop that includes a temperature control switch 34 . The temperature control switch 34 actuates the solenoid valve 29 between open and closed positions to control the flow of liquid cryogen to the spray nozzles 33 . Alternatively, the controller may be programmed to utilize an analog output in order to variably control a MOV valve that could be used in place of solenoid valve 29 to control the flow of liquid to the spray nozzles 33 .
[0042] The evaporator feed line 21 b includes a cryogenic ball valve 38 prior to entering the freeze compartment 30 a . Pressure (350 psi) relief valves 37 and 39 are preferably located between isolation valves 24 , 25 and 38 , and between isolation valve 29 and the internal evaporator 40 . The internal evaporator 40 is preferably mounted on the back interior wall of the freezer compartment 30 a . Alternatively, the evaporator 40 could be mounted on either side wall or ceiling of the freezer compartment 30 a , or may comprise two (2) or more internal evaporators connected in series or parallel within the freezer compartment 30 a . The internal evaporator 40 , which operates as the primary plant gas evaporator for the plant gas system 10 of the present invention, is preferably connected in series to an externally mounted secondary evaporator 41 . Both evaporators are preferably sized at 125% of plant gas capacity. As the temperature within the interior of the freezer compartment 30 a decreases, the primary/internal evaporator 40 becomes less and less efficient resulting in liquid cryogen flowing out of internal evaporator 40 into the external/secondary evaporator 41 . The secondary/external evaporator 41 is utilized to evaporate any liquid cryogen that exits the primary/internal evaporator 40 .
[0043] A primary gas line 42 extends from the external evaporator 41 to the gas reservoir 50 . Prior to the reservoir 50 and a junction with the secondary gas line 14 , the primary gas line 42 includes a pressure regulator 45 , a check valve 47 , an isolation ball valve 48 , and a pressure (350 psi) relief valve 46 preferably located between the pressure regulator 45 and the isolation valve 48 . The pressure regulator 45 preferably prevents liquid cryogen from being pumped into the reservoir 50 , while the check valve 47 , which is preferably a swing back type with a Teflon seat, preferably prevents back flow of gas from the secondary gas line 14 . Another isolation valve 49 is located along the primary gas line 42 after the junction with the secondary gas line 14 and prior to a gas inlet 51 on the reservoir 50 . The reservoir 50 includes a pressure relief valve 52 and a gas outlet 54 . Another isolation valve 55 is located on the plant gas line 56 , which feeds gas to the plant processes that utilize inert gas.
[0044] A blanket gas line 42 a preferably extends from the primary gas line 42 , just after the external evaporator 41 , back into the freezer 30 . The blanket gas system is activated when the freezer door 30 b is opened and creates a positive gas pressure in the freezer compartment 30 a . The positive gas pressure tends to prevent ambient air from entering the freezer 30 and causing the internal evaporator 40 and other components to ice up. The blanket gas line 42 a includes an isolation ball valve 43 and a solenoid valve 44 , which is actuated by a blanket gas control switch that is triggered by the opening of the freezer door 30 b.
[0045] In operation, plant gas is drawn off of the reservoir 50 through the reservoir outlet 54 causing the cryogen to flow in gas form through the liquid supply line 21 , the primary and secondary evaporators 40 and 41 , and the primary gas line 42 into the gas reservoir 50 , until the liquid supply line 21 cools to a temperature at which the cryogen remains a liquid. Once cryogen is flowing in liquid form through the liquid supply line 21 to the freezer 30 , it will flow through the internal primary evaporator 40 where it will expand into gas for the plant processes. The cooling properties of the internal primary evaporator 40 are harnessed by the freezer 30 to pre-cool the freezer compartment 30 a to approximately minus 100° F. As the interior of the freezer compartment 30 a becomes too cold for the primary evaporator 40 to effectively evaporate the liquid to gas, the secondary external evaporator 41 performs the necessary evaporation. By evaporating remotely at the freezer 30 , liquid tends to be immediately available when called for during the cooling process.
[0046] To begin the cooling process, the door 30 b of the freezer 30 is opened to insert the material to be treated. Opening the door 30 b triggers the solenoid 44 in the blanket gas line 42 a to open and feed blanket gas into the interior of the freezer compartment 30 a . The blanket gas creates a positive pressure within the freezer compartment 30 a and, thus, prevents ambient air from entering the freezer compartment 30 b . A load of material to be processed is then manually loaded, or loaded as part of an automated or semi-automated thermal processing line, into the freezer 30 . Once loaded, the freezer door 30 b is shut and the blanket gas solenoid 44 closes.
[0047] The material is then pre-cooled to a desired temperature or for a desired amount of time by using a pre-cool timer or a thermostat, which can be used to initiate the cooling cycle. Once the material has cooled to a desired temperature, such as minus 100° F., or for a desired period of time, a temperature set-point is read by or entered into the control system. The temperature control switch 34 actuates the sprayer solenoid valve 29 to enable liquid cryogen to flow to and out of the spray nozzles 33 . The circulation fan 35 is also activated to uniformly distribute the cool gas around the material. As the temperature within the freezer compartment approaches the set-point temperature, the temperature control switch 34 modulates the sprayer solenoid valve 29 to acquire and maintain the set-point temperature. The material will be cooled at the set-point temperature for an appropriate amount of time to obtain the desired mechanical properties for the material being treated. After the treatment process is completed, the freezer door 30 b is opened and the blanket gas system activated.
[0048] The control system includes a purge mode that enables a person to safely enter the freezer 30 and work on its internal components. The purge system will only work when the freezer door 30 b is open. When activated, the purge system disables the liquid cryogen supply to the spray nozzles 33 by closing the sprayer solenoid valve 29 , disables the blanket gas system by closing the blanket gas solenoid valve 44 , and activates the fan 35 to vent any residual gas left in the freezer compartment 30 a . The purge system preferably must be manually reset.
[0049] Turning to FIG. 3, a graph is shown in which use of liquid cryogen by the freezer 30 is plotted against the temperature acquired in the freezer compartment 30 a . As shown, the freezer 30 of the present invention does not use any liquid cryogen in a first or pre-cool temperature region (A) as the freezer 30 and material to be treated are cooled from an ambient temperature of approximately 80° F. to a pre-cooled temperature of approximately minus 100° F. In a second temperature region (B), which is between the pre-cooled temperature of approximately minus 100° F. and a transition temperature of approximately minus 225° F., liquid cryogen is sprayed from the nozzles 33 to further cool the freezer 30 and material. The freezer's 30 liquid cryogen use in this temperature region (B) appears to gradually increase as the temperature decreases. The increase in liquid cryogen usage per degree (F) change in temperature in this region (B) is relatively small until the temperature within the freezer 30 nears the transition temperature of approximately minus 225° F. The transition temperature is the temperature at which the freezer 30 tends to begin to use excess liquid for each degree (F) change in temperature. In the third temperature region (C), which includes temperatures at which deep cryogenic treatment is typically conducted, the freezer's liquid cryogen usage appears to increase exponentially for each degree (F) change in temperature as the temperature decreases from the transition temperature to approximately 320° F. While attempting to acquire and maintain a set-point temperature in this region (C), the spray nozzles 33 tend to approach operating at 100% capacity at 100% of the time.
[0050] To more economically accommodate the need for deep cryogenic treatment and avoid wasting liquid cryogen, the freezer 30 of the present invention preferably includes a liquid load basket 70 . As shown in FIG. 4, the liquid load basket 70 includes a generally box-like enclosure 71 mounted on an alloy tray 76 . The enclosure 71 includes an opening 73 at its top to vent expanding gas. The top of the enclosure 71 includes a pair of hingedly connected doors 74 and 75 . Mounted within the enclosure 71 are a series of liquid cryogen level detecting thermocouples 77 a - b corresponding to levels 14 , and a series of off-set level detecting thermocouples 78 a - d corresponding to off set levels 1-4. The basket 70 also includes a liquid feed line or connector 72 to fill the basket 70 with liquid cryogen. The feed line 72 includes a flexible hose with a twist lock type adapter for manual or semi-automatic systems, or a male or female quick disconnect spline-type coupler for fully automatic systems. Although the load basket feed line 72 is connectable to a liquid load connector 60 in the freezer 30 , and the liquid load basket 70 is preferably used in conjunction with the freezer 30 , it is also directly connectable to a source of liquid cryogen.
[0051] As shown in FIG. 2, the liquid load connector 60 is located at the end of a liquid load feed line 21 c , which branches off of the liquid supply line 21 . The liquid feed line 21 c includes an isolation ball valve 57 , a solenoid valve 59 , and a pressure (350 psi) relief valve 58 positioned there between.
[0052] In operation, the material to be processed by deep cryogenic treatment is placed within the liquid load basket 70 . The operator determines at which level the material will be completely submerged in the liquid cryogen and programs the desired level into the control system. The freezer door 30 b is opened and the blanket gas system is activated. The liquid load basket 70 is placed inside the freezer 30 and coupled to the connector 60 on the liquid load feed line 21 c of the freezer 30 . Once the liquid load basket 70 is inside the freezer 30 , the door 30 b closes and the blanket gas is shut off by closing the blanket gas solenoid valve 44 . The liquid load basket 70 is pre-cooled to a desired temperature or for a desired period of time in a manner discussed above. Once the pre-cool temperature is reached or the time runs out, a set point temperature, which preferably equals a temperature that is slightly higher than the transition temperature, is read by or entered into the control system. The temperature control switch 34 then actuates the sprayer solenoid valve 29 sending liquid cryogen to the spray nozzles 33 to acquire the desired set-point temperature within the freezer 30 . As described, the material advantageously goes through two (2) steps of pre-cooling prior to being immersed in the liquid cryogen. The liquid cryogen usage within the liquid load basket 70 will tend to be lower than established methods as a result.
[0053] When the set-point temperature is reached, a fill control switch actuates the sprayer solenoid valve 59 to fill the liquid load basket 70 to a desired level. Assuming for exemplary purposes the set-point level is set at level 2, the control system will allow the basket 70 to fill with liquid until the level 2 off-set thermocouple 78 b , senses a temperature equivalent to the liquid temperature of the cryogen, which is minus 320° F. for nitrogen, indicating that the liquid has reached the level 2 off-set. The fill control switch closes the solenoid valve 59 when the off-set thermocouple 78 b senses the liquid temperature. The control system will maintain the liquid cryogen in the liquid load basket 70 at or above level 2 during the deep cryogenic treatment process by replenishing the liquid as it evaporates. More particularly, when the set-point thermocouple 77 b senses a temperature above the liquid temperature of the cryogen, e.g., minus 319° F. for nitrogen, indicating that the liquid level has fallen below the desired level, the fill control switch opens the solenoid 59 to fill the liquid load basket 70 with liquid cryogen until the off-set thermocouple 78 b again senses the liquid temperature. After the treatment process is completed, the freezer door 30 b can be opened to allow the liquid cryogen in the liquid load basket 70 to evaporate into the atmosphere.
[0054] Alternatively, the liquid load basket 70 may be completely enclosed and include an exhaust gas outlet 80 feeding a gas line 79 , which may advantageously be coupled to a pneumatic gas system reservoir (not shown). In addition, in an attempt to reduce waste, the liquid load basket 70 may advantageously be connected via appropriate piping and valves to a liquid load recycle reservoir (not shown). During the deep cryogenic treatment process, evaporated gas is allowed to freely vent through gas outlet 80 and gas line 79 into the pneumatic gas reservoir. Once the treatment process is completed, a solenoid operated valve (not shown) in the pneumatic gas supply line 79 is closed. As the liquid cryogen in the liquid load basket 70 evaporates into gas, the pressure increases within the basket 70 to a level sufficient to force the remaining liquid cryogen out of the liquid load basket and into the liquid load recycle reservoir. Another solenoid valve (not shown) can be actuated to shut off access to the recycle reservoir when the control system senses that the liquid cryogen has been evacuated from the liquid load basket 70 . The control system preferably includes programming logic that enables the liquid cryogen stored in the recycle reservoir to be used in a subsequent deep cryogenic treatment prior to drawing liquid from the liquid feed supply line 21 c.
[0055] Other alternative embodiments to the present invention include using one gas or combination, for example, oxygen or helium or both, in liquid form, for pre-cooling, i.e., passing the liquid through the freezer's internal evaporator 40 where it is expanded into gas for other uses, and then using another gas or combination, such as nitrogen or argon or both, in liquid form for the cooling process.
[0056] In another alternative embodiment, established freezer installations can be retrofitted to take advantage of the cooling properties of an evaporator and the liquid savings associated with evaporating inside the freezer. An established freezer installation 100 , as shown in FIG. 5, typically includes a liquid storage tank 120 , a supply conduit 121 , and a freezer 130 with spray nozzles 133 . An isolation valve 122 is located adjacent the tank 120 and a control valve 125 is installed in the supply line 121 prior to the freezer 130 to control the flow of liquid into the freezer 130 . To ensure liquid is available at the freezer 130 , a pressure actuated valve 124 is typically installed in the supply line 121 prior to the control valve 125 . The pressure actuated valve 124 is used to vent gas from the supply line 121 to atmosphere (A) until the line 121 is sufficiently cool for liquid to flow. The valve 124 closes when liquid reaches the valve 124 to enable liquid to flow to the freezer 130 .
[0057] Turning to FIG. 6, the pre-cooling benefits and some of the liquid savings of the present invention can easily be taken advantage of by retrofitting the existing installation of FIG. 5. The existing installation 100 can be retrofitted by removing the pressure actuated valve 124 and vent line 124 a and installing an evaporator or heat exchange 140 within the freezer 130 . An evaporator feed line 123 branches off of the supply line 121 and feeds liquid to the evaporator 140 . After the liquid passes through the evaporator 140 , the exiting gas can be vented to atmosphere (A) or to plant or pneumatic gas systems (P). A pressure regulator 126 can be used to vent gas around the evaporator 140 along a by-pass line 128 to exit side of the evaporator 140 until liquid flows through the supply line 121 . A check valve 127 can be installed to prevent the back flow of gas.
[0058] While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims. | An improved freezer and plant gas system that harnesses the cooling properties of the plant gas evaporator to facilitate energy and cryogen savings, as well as the automation and optimization of a plant thermal processing system. The freezer preferably includes an internally mounted evaporator sized to meet the gas requirements of the plant processes requiring inert gas. By evaporating the plant gas in the freezer, the freezer can be remotely located from the liquid cryogen source while still making liquid cryogen available when called for during a cryogenic treatment process metal or other materials. In addition, by evaporating in the freezer the freezer is able to harness the cooling properties of the evaporator to pre-cool the freezer and material prior to use of liquid in the cooling cycle. Alternatively, a liquid load basket is adapted to economically thermally treat materials in a deep cryogenic treatment. | 2 |
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a rotating signal light for use on emergency and other vehicles, such as police cars and ambulances, and in particular to a rotating light supplied with power from a variable voltage lamp circuit which provides increased voltage in certain predetermined rotational positions of the light in order to produce increased intensity light flashes in selected directions while providing reduced voltage when the lamp is aimed in other directions where light flashes of reduced intensity are sufficient.
It is possible to vary the effective intensity of a rotating light by varying its speed of rotation. A method and apparatus for increasing effective light intensity by varying the speed of rotation of a light are disclosed in my copending application, Ser. No. 46,173, filed June 7, 1979, which application is assigned to the assignee of the present invention. However, the present invention concerns a light which is rotated at a constant speed.
In accordance with a preferred embodiment of the present invention, a rotatable light is mounted on the roof of an emergency vehicle for rotation about an approximately vertical axis to direct light in all directions from the vehicle. It will be understood that from a particular vantage point, such as forwardly of the emergency vehicle on which the light is mounted, the effect is a series of inermittent light flashes which are effective as a warning signal.
In many such applications, it is of greater importance to have high intensity light flashes in certain directions, as for example forwardly of the vehicle, or forwardly and rearwardly, compared to other directions such as to the sides of the vehicle. The present invention is related to a rotating light for applications of the foregoing type where light flashes of maximum intensity are not required in all directions.
The intensity of light emitted in a given direction from a rotating lamp, i.e., the candlepower of the lamp in a given direction, is proportional to lamp voltage. Specifically, candlepower is proportional to voltage taken to the 3.5 power. Accordingly, a relatively small reduction in voltage will afford a much more significant reduction in candlepower. On the other hand, a relatively small increase in lamp voltage will produce a much more significant reduction in lamp life, since lamp life is inversely proportional to lamp voltage taken to the 12th power.
It is therefore a general object of the present invention to provide a rotatable warning light in conjunction with a variable voltage lamp circuit, which light is more efficient than conventional constant voltage lights and has unusually long life.
A more specific object of the invention is to increase lamp life for a rotating warning light by providing maximum lamp voltage only when the lamp is aimed in certain predetermined directions where maximum intensity light flashes are required and by reducing lamp voltage when the lamp is aimed in other directions.
In furtherance of the foregoing objectives, it is preferred to use a lamp of a type which normally has a relatively short life at normal voltage, but offers high light efficiency. By using such a lamp in accordance with the present invention, the high light efficiency offered by the lamp at normal voltages can be achieved in certain relatively short selected positions of the light, and yet the normal limited life of such a high intensity lamp can be significantly increased by reducing lamp voltage in other positions of the light.
In other words, it will be understood that high efficiency lamps normally have only a relatively short life, whereas lamps which offer a long life normally afford only relatively low light efficiency. It is an object of the present invention to utilize a lamp of the type which offers high efficiency and a relatively short life at normal voltage, and to increase the lamp life significantly by reducing voltage during a significant portion of the time during which the lamp is operated, thereby achieving maximum light efficiency in selected directions while achieving extended lamp life.
A further more specific object of my invention is to provide a rotating light for mounting on the top of an emergency vehicle, which light is used in conjunction with a variable voltage lamp circuit providing relatively high voltage when the lamp is aimed forwardly of the vehicle, or forwardly and rearwardly, while providing reduced voltage when the lamp is aimed to the sides of the vehicle.
The foregoing and other objects and advantages of the invention will be apparent from the following description of a preferred embodiment, taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a rotating light assembly constructed in accordance with the present invention;
FIG. 2 is a vertical section taken substantially along the line 2--2 of FIG. 1; and
FIG. 3 is a schematic wiring diagram showing the manner in which variable voltage power is supplied to a rotating lamp and constant voltage is supplied to a motor for rotating a lamp holder.
Now, in order to acquaint those skilled in the art with the manner of making and using my invention, I shall describe, in conjunction with the accompanying drawings, a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIGS. 1 and 2 illustrate a mounting platform 10 having four upwardly extending mounting posts 12, and four depending leg members 14 which terminate at a base 16. Base 16 may be secured by bolts or the like to the roof of an emergency vehicle, such as a police car or ambulance.
At the center of the mounting platform 10 there is a vertical integral sleeve 18, best shown in FIG. 2 in which is mounted a bushing 20. A light supporting shaft 22 is journaled in bushing 20, and shaft 22 includes a reduced diameter upper shaft portion 24. A washer 26 is mounted on the shaft at the top of bushing 20, and a second washer 28 is located on the shaft at the underside of the bushing.
A lamp holder 30 includes a mounting sleeve 32 at its lower end which mounts over the upper end 24 of shaft 22. The sleeve 32 is secured to shaft end 24 by a press fit or threads or other means which fixedly mounts lamp holder 30 on shaft 22 for conjoint rotation therewith.
Lamp holder 30 carries a lamp 34 which directs light in a 360 degree arc as shaft 22 is rotated. FIG. 1 shows a constant speed motor 36 which drives a worm 38 (shown in FIG. 2), and worm 38 meshes with a worm gear 40. Worm gear 40 is keyed or otherwise fixedly mounted on a mounting sleeve 42 which mounts over the lower end of shaft 22 and is fixedly secured thereto by a set screw 44. In the foregoing manner, motor 36 rotates lamp holder 30 causing lamp 34 to rotate continuously about the approximately vertical axis of shaft 22 thereby producing light flashes in all horizontal directions from an emergency vehicle on which the warning light is mounted.
Reference is now made to FIG. 3 which is a schematic wiring diagram of a variable voltage lamp circuit in accordance with the present invention. A 14 VDC power source is shown at 50, and also a terminal board 51 having terminals 52, 54 and 56. A segmented collector ring 57 is also illustrated, comprising a large ring segment 58 and a small ring segment 60. There are further shown a brush 62 which cooperates with the collector ring segments, and a resistance 64.
Most of the foregoing components are also shown in FIGS. 1 and 2 which illustrate collector ring segments 58 and 60 secured on the top of posts 12 by screws 66. Fig. 2 also shows brush 62 mounted on the underside of a bracket 68 which is a part of a lamp holder 30 and rotates therewith. During rotation of lamp holder 30 by motor 36, brush 62 moves around the top of collector ring 57 engaging seriatim with ring segments 58 and 60. As will be explained more fully hereinafter, the relatively short ring segment 60 is located in a predetermined position to assure it will be in contact with brush 62 when lamp 34 is facing a direction in which it is desired to provide high intensity light flashes, e.g., when lamp 34 is facing forwardly relative to the emergency vehicle on which it is mounted.
Referring again to FIG. 3, power source 50 is connected through lead 70 to terminal 52 which in turn connects to motor 36 through lead 72. Motor 36 is connected to terminal 54 through lead 76, and the latter terminal is grounded through lead 78. Thus, when the light assembly is operative, motor 36 is driven continuously from power source 50 to rotate lamp holder 30 and lamp 34 at a constant speed.
In accordance with the present invention, lamp voltage is varied as lamp 34 rotates. In the embodiment described, the lamp is operated at normal or relatively high voltage when brush 62 is engaged with ring segment 60, and the lamp is operated at reduced voltage during the major portion of the 360 degree revolution of the lamp when brush 62 is engaged with ring segment 58. As shown in FIG. 3, when brush 62 is engaged with ring segment 58, power 50 is connected through lead 70, terminal 52, lead 80, resistance 64, terminal 56, lead 82, ring segment 58, brush 62 and lead 84 to lamp 34 which is grounded through lead 86.
Because of the presence of resistance 64 in the above-described circuit, lamp 34 receives reduced voltage during that portion of each revolution when brush 62 is engaged with ring segment 58. However, during that portion of each revolution that brush 62 is engaged with ring segment 60, power source 50 is connected through lead 70, terminal 52, lead 88, ring segment 60, brush 62 and lead 84 to lamp 34. Accordingly, resistance 64 is shorted out of the lamp circuit during that portion of each revolution that brush 62 engages ring segment 60, and therefore lamp 34 is operated at a higher voltage to emit higher intensity light.
As explained above, ring segment 60 is located so lamp 34 will be operated at higher voltage when it is aimed in a predetermined direction in which it is desired to provide greater light intensity. By way of example, when the light assembly is mounted on a police car, it may be desired to locate ring segment 60 so lamp 34 will operate at higher voltage when aimed forwardly relative to the police vehicle.
It will be understood more than one section of increased voltage may be provided for each revolution of the lamp. For example, two ring segments 60 may be provided in opposed relation so that increased intensity light flashes will be produced when the lamp is aimed either forwardly or rearwardly relative to the emergency vehicle on which it is mounted, and yet the lamp may still be operated at reduced voltage during a major portion of each revolution.
It is important to understand that by using the present invention it is possible to provide very high intensity light in selected areas with relatively low power, and at the same time achieve relatively long lamp life which is quite important with emergency rotating warning lights. In contrast, it is normally necessary to choose between high efficiency and long life, since available lamps do not normally afford both characteristics.
Moreover, in many applications for rotating warning lights, it is not necessary to provide the same high intensity light in all directions. Thus, in the case of a rotating light mounted on the top of a police car, it is often considered important to provide high intensity light flashes only in a direction forwardly of the vehicle, or forwardly and rearwardly, whereas lower intensity light flashes may be sufficient in other directions.
In addition to achieving longer lamp life, it is also important that use of the present invention reduces wattage requirements for a rotating warning light. For example, certain U.S. Government specifications for rotating light systems for emergency vehicles set relatively high minimum light intensity requirements in the front and rear directions, and a minimum flash rate, and also set relatively low amperage requirements which must not be exceeded by a complete lighting system. The present invention offers an improved lighting system capable of satisfying such demanding requirements.
One specific example of a lamp which can be used with the present invention is a No. 4509 aircraft landing lamp which has a normal useful life of 25 hours. Such a lamp is capable of providing high light intensity, and yet its normal relatively short life can be increased substantially if it is operated at a reduced voltage during a major portion of its operating time. | A rotating signal light for use on police cars, ambulances and other vehicles on which a warning light is required, the light being connected with a variable voltage lamp circuit which provides a higher voltage in predetermined rotational positions of the lamp to produce enhanced light in certain directions while providing a lower voltage in other positions of the light to increase lamp life and reduce wattage requirements. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Division of prior copending U.S. application Ser. No. 12/857,709 which was filed on Aug. 17, 2010, the contents of which are incorporated herein by reference thereto.
FIELD OF THE INVENTION
[0002] The invention relates to a system for reducing CO concentration in an ethylene rich stream.
DESCRIPTION OF RELATED ART
[0003] Industrial processes for producing ethylene include catalytic and thermal cracking of hydrocarbon feedstocks. In at least some cases, the cracking process effluent contains carbon monoxide. For example, certain product separation and recovery systems produce a vapor stream rich in ethylene and containing hydrogen, methane, acetylene, ethane and other contaminants such as CO, CO 2 , and H 2 S that must be removed in order to produce a high purity ethylene product. Acetylene in polymer grade ethylene is typically limited to a maximum of 5 vol ppm. A typical polymer grade ethylene specification is shown in Table 1.
[0000]
TABLE 1
Typical Polymer Grade Ethylene Specifications
Ethylene
99.90
vol % min
Methane plus ethane
1000
vol ppm max
Ethane
500
vol ppm max
Acetylene
5
vol ppm max
C3 and heavier
10
vol ppm max
CO
2
vol ppm max
CO 2
5
vol ppm max
Sulfur
2
wt ppm max
[0004] Acetylene removal is typically effected by acetylene conversion to ethylene via selective hydrogenation. Carbon monoxide (CO) attenuates the activity of the commonly used acetylene selective hydrogenation catalysts and thus excessive CO concentration can be problematic.
[0005] Hence it would be beneficial to be able to control the amount of CO that enters the acetylene conversion unit.
SUMMARY OF THE INVENTION
[0006] The present invention relates to controlling CO concentration in a stream prior to subjecting the stream to an acetylene selective hydrogen catalyst.
[0007] One embodiment of the invention is directed to a system for acetylene selective hydrogenation of an ethylene rich gas stream comprising: (a) an ethylene rich gas supply comprising at least H 2 S, CO 2 , CO, and acetylene; (b) a first treatment unit for removing H 2 S and, optionally, CO 2 from the gas stream; (c) a CO oxidation reactor to convert CO to CO 2 and forming a CO-depleted gas stream; (d) a second treatment unit for removing the CO 2 from the CO-depleted gas stream; and (e) an acetylene selective hydrogenation downstream of the CO oxidation reactor.
[0008] Another embodiment of the invention is directed to a process for acetylene selective hydrogenation of an ethylene rich gas stream comprising: (a) supplying an ethylene rich gas comprising at least H 2 S, CO 2 , CO, and acetylene to a first treatment unit and removing H 2 S and, optionally, CO 2 from the gas stream; (b) supplying the H 2 S and CO 2 free gas stream to an CO oxidation reactor and converting CO to CO 2 to form a CO-depleted gas stream; (c) supplying the CO-depleted gas stream to a second treatment unit to remove the CO 2 from the CO-depleted gas stream; and (d) treating the CO-depleted or CO-depleted gas stream to an acetylene selective hydrogenation unit to convert the acetylene to ethylene.
[0009] These and other embodiments relating to the present invention are apparent from the following Detailed Description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic of part of a PetroFCC™ product treating and recovery system.
[0011] FIG. 2 is a schematic of an ethylene rich lean gas preferential CO oxidation reactor system in accordance with one embodiment of the invention.
[0012] FIG. 3 is a schematic of ethylene rich lean gas preferential CO oxidation reactor system in accordance with another embodiment of the invention.
[0013] The same reference numbers are used to illustrate the same or similar features throughout the drawings. The drawings are to be understood to present an illustration of the invention and/or principles involved.
DETAILED DESCRIPTION
[0014] FIG. 1 is a schematic of a separation scheme for recovering ethylene and propylene. A vapor stream ( 2 ) comprised of ethylene and propylene is compressed ( 4 ) to produce a propylene rich liquid stream ( 6 ) and an ethylene rich vapor stream ( 7 ). The ethylene vapor stream ( 7 ) is treated and concentrated in a primary absorber ( 8 ) and a sponge absorber ( 10 ) to form an ethylene rich lean sponge gas ( 12 ). The lean sponge gas ( 12 ) includes other light hydrocarbons, primarily hydrogen, methane, acetylene, ethane and other contaminants such as CO, CO 2 , and H 2 S that must be removed in order to produce a high purity ethylene product.
[0015] The ethylene and propylene stream may be obtained from any industrial process for producing ethylene including catalytic and thermal cracking of hydrocarbon feedstock product streams. For example, US20080078692 discloses a hydrocarbon cracking process and subsequent treatment of the effluent streams. US 20080078692 discusses various conventional terms and process steps used in processes for recovering ethylene and propylene after a hydrocarbon cracking process, see especially paragraphs 0012-0018, 0034-0041, 0045-0055, and is hereby incorporated by reference in its entirety,
[0016] The ethylene purification scheme shown in FIG. 1 includes an amine treatment unit ( 14 ) to remove H 2 S and CO 2 from the ethylene rich lean sponge gas ( 12 ) forming stream ( 22 ). Treatment in the amine treatment unit reduces the H 2 S to less than about 0.1 ppm and CO 2 to less than about 50 ppm. The stream ( 22 ) is then fed to an acetylene selective hydrogenation unit ( 16 ) to hydrogenate the acetylene into ethylene.
[0017] In the scheme shown in FIG. 1 , acetylene is hydrogenated upstream of the demethanizer ( 18 ) and ethane-ethylene splitter fractionators ( 20 ). For this example, stream ( 22 ) includes sufficient hydrogen for hydrogenating the acetylene in the gas to ethylene. Hence, no additional hydrogen is required to be added to the feed stream into the acetylene selective hydrogenation unit ( 16 ). Additionally, the acetylene selective hydrogenation unit ( 16 ) normally operates above ambient temperature while the demethanizer ( 18 ) and ethane-ethylene splitter ( 20 ) typically operate sub-ambient. Positioning the CO oxidation reactor and acetylene conversion reactor upstream of the demethanizer lessens feed heating and effluent cooling duty compared to an arrangement that includes CO oxidation and acetylene conversion in the sub-ambient section of the process.
[0018] The concentration of CO in stream ( 22 ) is variable, generally in a range of 0 to 6 vol %. It is desirable to maintain the CO concentration of the stream ( 22 ) (the acetylene selective hydrogenation reactor feed stream) within a certain operating range, typically about 1 to 0.2 vol %. In general, as the CO concentration of the acetylene selective hydrogenation reactor feed stream increases, the operating window of the acetylene selective hydrogenation reactor system and the time between catalyst regenerations decreases.
[0019] The operating window is the set of operating conditions that enables selective and stable performance. Specifically, allowing complete hydrogenation of acetylene while minimizing hydrogenation of ethylene to ethane. The operating window is affected by process conditions including reactor inlet temperature, feed acetylene, hydrogen, and CO concentrations, space velocity, and catalyst type.
[0020] Thus, as discussed above, the feed stream ( 22 ) entering the acetylene selective hydrogenation unit ( 16 ) often contains unacceptably high carbon monoxide (CO) concentrations. The present invention is directed to a process of controlling or reducing the amount of CO in feed stream ( 22 ) entering an acetylene selective hydrogenation unit ( 16 ).
[0021] The feed stream ( 12 ) from the sponge absorber contains unacceptably high levels of CO. An oxidation reactor will oxidize CO in the feed stream using elemental oxygen as an oxidant: “CO+0.5 O 2 →CO 2 ”. The CO to CO 2 conversion selectivity depends on the catalyst choice and composition of the feed stream. However, the feed stream ( 12 ) from the sponge absorber contains H 2 S which is a catalyst poison for oxidation and must be removed from the feed stream prior to entering the oxidation reactor.
[0022] It was discovered that placing a CO oxidation reactor downstream of the amine treatment unit ( 14 ) enables control of the CO concentration in the feed to the acetylene selective hydrogenation unit ( 16 ). As shown in FIG. 2 , the ethylene rich stream ( 12 ) from the sponge absorber (not shown) flows to a first amine treatment unit ( 14 ). For this illustration, it is assumed that the first amine treatment unit ( 14 ) removes both H 2 S and CO 2 even though CO 2 removal upstream of the oxidation reactor is not required. Thus, the process does not require CO 2 removal at this stage.
[0023] The ethylene rich stream from the amine treatment unit ( 14 ), essentially H 2 S and CO 2 free, is combined with a stream ( 32 ) that provides a source of elemental oxygen, for example, air or oxygen enriched air. The combined gases A (H 2 S and CO 2 -depleted stream) flow to the CO oxidation reactor ( 30 ). After CO conversion to CO 2 , the effluent stream B (CO-depleted stream) continues to a second amine treatment unit ( 34 ) downstream of CO oxidation reactor ( 30 ). This second amine treatment unit ( 34 ) removes CO 2 from effluent stream B. The CO 2 -depleted effluent then continues to the acetylene selective hydrogenation unit ( 16 ).
[0024] As also shown in FIG. 2 , the amine treating arrangement uses a common amine regenerator ( 36 ) to regenerate rich amine from both the first and second amine treatment units ( 14 ) and ( 34 ). In doing so, amine treating equipment is minimized. The combination of the preferential CO oxidation reactor ( 30 ) and amine treatment unit ( 14 ) to remove H 2 S enables control of the CO concentration within a suitable range for subsequent acetylene conversion via conventional selective hydrogenation technology.
[0025] A sensor ( 38 ) may be placed in the effluent B stream after the CO oxidation reactor ( 30 ) to detect the amount of CO in the stream. The sensor may be placed at any position subsequent to the CO oxidation reactor where CO is present in detectable levels. The sensor may signal whether the amount of oxygen or air supplied by line ( 32 ) should be modified. The effluent stream B ideally comprises less than about 50 ppm-vol CO.
[0026] The oxidation temperature in the CO oxidation reactor ( 30 ) is typically between about 70° C. and about 160° C.
[0027] Suitable catalysts for selectively oxidizing CO using air or oxygen enriched air include, but are not limited to ruthenium metal disposed on an alumina carrier, such as those described in U.S. Pat. No. 6,299,995, hereby incorporated by reference in its entirety. The ruthenium metal comprises well dispersed ruthenium crystals having an average crystal size less than or equal to about 40 angstroms. Other suitable catalysts utilize platinum and copper.
[0028] Other treatments may be used instead of amine treatment units. Alternative treatment units include absorbers with amine or solvent flow arranged in a cascading relationship. As shown in FIG. 3 , an ethylene rich feed gas ( 12 ) flows into a first absorber ( 40 ) wherein H 2 S and CO 2 are removed by absorption. The ethylene rich stream from the first absorber ( 40 ), essentially H 2 S and CO 2 free, is combined with a stream ( 47 ) that provides a source of elemental oxygen. The combined gases A (H 2 S and CO 2 -depleted stream) flow to the CO oxidation reactor ( 42 ). After CO conversion to CO 2 , the effluent stream B (CO-depleted stream) continues to a second absorber ( 44 ) downstream of CO oxidation reactor ( 42 ). This second absorber ( 44 ) removes CO 2 from effluent stream B. The CO 2 -depleted effluent then continues to an acetylene selective hydrogenation unit (not shown). The CO 2 rich amine from the second absorber ( 44 ) flows to first absorber ( 40 ). The CO 2 and H 2 S rich amine from the first absorber ( 40 ) flows to an amine regenerator ( 46 ). The lean amine from the amine regenerator ( 46 ) then flows into the second absorber ( 44 ). A CO sensor (not shown) may be placed downstream of CO oxidation reactor ( 42 ) similar to the system shown in FIG. 2 in order to control the amount of air or oxygen added to combined gases A.
[0029] In the amine treatment unit ( 14 ) shown in FIGS. 1 , ( 14 ) and ( 34 ) shown in FIGS. 2 , ( 40 ) and ( 44 ) shown in FIG. 3 selective removal of H 2 S and CO 2 can be achieved using amine-containing chemical solvents. For example, UOP AMINE GUARD™ FS may be used to remove the H 2 S and CO 2 . Such solvents provide selective removal of H 2 S via amine selection. Other treatment units may use other chemical solvents. Chemical solvents are used to remove the acid gases by a reversible chemical reaction of the acid gases with an aqueous solution of various alkanolamines or alkaline salts in water.
[0030] Other treatment units may utilize physical solvents. With a physical solvent, the acid gas loading in the solvent is proportional to the acid gas partial pressure. For example, the UOP SELEXOL™ process may be used which uses a physical solvent made of dimethyl ether of polyethylene glycol. Chemical solvents are generally more suitable than physical or hybrid solvents for applications at lower operating pressures.
[0031] As discussed above, in accordance with the present invention, a CO oxidation reactor is placed upstream of the acetylene selective hydrogenation unit to enable control of the CO concentration within a suitable range for the acetylene selective hydrogenation reaction occurring in the acetylene selective hydrogenation unit. Further aspects of the invention are therefore directed to a method for controlling the CO concentration in an acetylene selective hydrogenation unit feed stream by preferential CO combustion (i.e. oxidation) with air or oxygen enriched air providing the oxygen.
EXAMPLES
[0032] The following examples and tables summarize the expected performance of the preferential CO oxidation reactor processing a typical ethylene-rich lean gas as shown in FIG. 2 . Stream “A” is oxidation reactor feed and “B” is oxidation reactor effluent. The examples assume selectivity based on a ruthenium on alumina catalyst.
Example 1
[0033] The lean gas (i.e. H 2 S and CO 2 removed) from the amine treatment unit is mixed with air. The oxygen available for oxidizing CO is controlled to limit the CO conversion to ˜50%. As shown in Table 2, the CO concentration is reduced from ˜2600 ppm to ˜1300 ppm.
[0034] Specifically, stream A is introduced into a CO oxidation reactor and stream B exits the reactor under the following conditions:
[0000]
Inlet
Outlet
Reactor Temperature (° F.)
194
221
Reactor Pressure (psia)
246.7
Air to Reactor (lbmol/hr)
66
[0000]
TABLE 2
Stream “A”
Stream “B”
Mole
Mole
Fraction
Mole %
Fraction
Mole %
H 2 O
0.003869
0.387
H2O
0.005189
0.519
Oxygen
0.001314
0.131
Oxygen
0.000000
0.000
Nitrogen
0.068311
6.831
Nitrogen
0.068401
6.840
Hydrogen
0.106621
10.662
Hydrogen
0.105446
10.545
CO
0.002615
0.262
CO
0.001303
0.130
CO 2
0.000005
0.001
CO 2
0.001321
0.132
Methane
0.248449
24.845
Methane
0.248775
24.878
Acetylene
0.000503
0.050
Acetylene
0.000504
0.050
Ethylene
0.485833
48.583
Ethylene
0.486472
48.647
Ethane
0.076446
7.645
Ethane
0.076546
7.655
Propylene
0.006035
0.604
Propylene
0.006043
0.604
Example 2
[0035] The lean gas (i.e. H 2 S and CO 2 removed) from the amine treatment unit is mixed with air. The oxygen available for oxidizing CO is controlled to limit the CO conversion to ˜75%. The CO concentration is reduced from ˜2600 ppm to ˜600 ppm, see Table 3. Undesirable side reactions include “H 2 +0.5 O 2 →H 2 O”, as well potential oxidation of light hydrocarbons including olefin products. Assuming sufficient reactant, the CO oxidation reactor essentially completely removes CO.
[0036] Stream A is introduced into a CO oxidation reactor and stream B exits the reactor under the following conditions:
[0000]
Inlet
Outlet
Reactor Temperature (° F.)
194
234
Reactor Pressure (psia)
246.7
Air to PreFOX Reactor (lbmol/hr)
99
[0000]
TABLE 3
Stream “A”
Stream “B”
Mole
Mole
Fraction
Mole %
Fraction
Mole %
H 2 O
0.003857
0.386
H 2 O
0.005833
0.583
Oxygen
0.001965
0.196
Oxygen
0.000000
0.000
Nitrogen
0.070561
7.056
Nitrogen
0.070700
7.070
Hydrogen
0.106289
10.629
Hydrogen
0.104530
10.453
CO
0.002607
0.261
CO
0.000644
0.064
CO 2
0.000005
0.001
CO 2
0.001973
0.197
Methane
0.247674
24.767
Methane
0.248161
24.816
Acetylene
0.000501
0.050
Acetylene
0.000502
0.050
Ethylene
0.484318
48.432
Ethylene
0.485271
48.527
Ethane
0.076207
7.621
Ethane
0.076357
7.636
Propylene
0.006016
0.602
Propylene
0.006028
0.603
[0037] In view of the present disclosure, it will be appreciated that other advantageous results may be obtained. Those having skill in the art, with the knowledge gained from the present disclosure, will recognize that various changes can be made in the above apparatuses and methods without departing from the scope of the present disclosure. Mechanisms used to explain theoretical or observed phenomena or results, shall be interpreted as illustrative only and not limiting in any way the scope of the appended claims. | A system and process for acetylene selective hydrogenation of an ethylene rich gas stream. An ethylene rich gas supply comprising at least H 2 S, CO 2 , CO, and acetylene is directed to a first treatment unit for removing H 2 S and optionally CO 2 from the gas stream. A CO oxidation reactor is used to convert CO to CO 2 and form a CO-depleted gas stream. A second treatment unit removes the CO 2 from the CO-depleted gas stream and an acetylene selective hydrogenation treats the CO-depleted gas stream. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This application for patent claims the benefit of priority from, and hereby incorporates by reference the entire disclosure of, co-pending U.S. Provisional Application for Pat. No. 60/370,322, filed Apr. 4, 2002.
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The invention disclosed and claimed herein generally pertains to an apparatus for use in connection with a quadrature switching mixer configured to reject an image signal associated with a received RF signal. More particularly, the invention pertains to an apparatus of the above type which substantially reduces leakage between the in phase (I) and quadrature (Q) output branches of the mixer, and thereby improves the conversion gain of the mixer and avoids deterioration of the mixer output signal.
2. History of the Related Art
In radio equipment, the signals transmitted through the air occupy one frequency band, whereas the signals that are processed occupy a considerably lower frequency band. Accordingly, a mixer is used to translate or convert the radio frequency signals to an intermediate frequency (IF). The mixing process, or heterodyning, is multiplicative, that is, the input signal is multiplied by a local oscillator signal (in the time domain). As a result of the multiplication, however, the output of the mixer may include contributions from the desired signal as well an undesired image signal. Those of ordinary skill in the radio reception art know that the image signal is a signal whose frequency is capable of being converted, via the mixing process, to the same IF as the desired signal.
Image rejection mixers have been developed which use the principle of canceling to reduce the contribution of the image signal at the mixer output. In one commonly used type of image rejection mixer, the desired input signal (RF) is split into two signal components: an in-phase (I) component (RF I ) and a quadrature (Q) component (RF Q ). The quadrature (Q) signal is delayed 90 degrees relative to the in-phase (I) signal, that is: RF Q (ωt)=RF I (ωt−π/2). The local oscillator signal is also split into a quadrature signal LO Q which is delayed 90 degrees relative to the in-phase oscillator signal LO I . Mathematically, in complex notation, the image rejection mixer works as a multiplication of the input signal RF I +jRF Q with the local oscillator signal LO I +jLO Q .
As described hereinafter in further detail, the multiplication is usually implemented with commuting switches. Each commuting switch has a pair of complementary switches SW and {overscore (SW)}. When the SW switch is closed, the output signal of the commuting switch has the same polarity as the input signal, and when the {overscore (SW )} switch is closed, the output signal of the commuting switch has a different polarity than the input signal. Summing junctions are then provided for cancellation of the components representing the undesired image signal. This type of image rejection mixer is referred to as a quadrature switching mixer.
The components for a quadrature switching mixer of the type described above can be fabricated using any suitable semiconductor technology such as CMOS, BJT, and the like. This provides certain important advantages when the mixers are used in wireless receivers for small portable electronic devices, such as mobile phones and the like for use in UMTS (Universal Mobile Telecommunications System), Bluetooth, and other wireless communication systems. CMOS based quadrature switching mixers, however, have a serious drawback in that the I and Q output signal components of the mixer, OUT I and OUT Q respectively, tend to short together. That is, a portion of one of the quadrature branch outputs may flow backward through one of the switches in the mixer, and enter the input of the other branch. This leakage can cause a conventional quadrature image rejection mixer of the type mentioned above to become less useful in practice, because of the resulting large conversion loss. Moreover, the leakage between the two outputs OUT I and OUT Q deteriorates the cumulative mixer output signal and leads to poor image rejection ratios.
One presently used approach to reduce the leakage between the I and Q output signals of a quadrature switching mixer is to add resistors in series with the switches, thereby effectively isolating the I and Q branches from each other. A switch, however, should have low resistance when it is closed to minimize any signal loss. Adding isolation resistors introduces an additional loss. This loss can be significant, even though it is usually less than the loss resulting from leakage between the I and Q branch output signals. The added resistors also cause an undesirable voltage drop, especially if the signal is in current mode, which means that the input impedance of the mixer should be kept low. Therefore, it is undesirable to add any further resistors to the quadrature switching mixer.
Accordingly, it would be desirable to be able to reduce the leakage between the I and Q output signals of a quadrature switching mixer, and to be able to do so without introducing additional loss to the mixer such as from isolation resistors.
SUMMARY OF THE INVENTION
The present invention provides an effective and comparatively simple technique for substantially reducing leakage between the outputs of the I and Q branches of a quadrature switching mixer. In accordance with the invention, a unidirectional device, such as a component that is part of a signal splitter, is inserted into the input path of each switch of the mixer. Each of the unidirectional devices acts to prevent an output signal from one of the branches from leaking backward through an input path to the other branch output. Deterioration of the I and Q signals outputted from the quadrature switching mixer is thus significantly reduced. As a result, a passive quadrature switching mixer is made available that is highly linear, has low noise mixing capabilities, and can be efficiently used for image rejection mixing.
In one embodiment, the invention is directed to switching mixer apparatus for mixing an RF signal and a local oscillator signal. The apparatus comprises a configuration of switching devices, each of the switching devices configured to multiply respective in-phase (I) and quadrature (Q) components of the RF and LO signals to provide I and Q output signal components. The apparatus further comprises a first RF input path for coupling an I component of the RF signal to at least one of the switching devices, a second RF input path for coupling a Q component of the RF signal to at least one other of the switching devices, and a unidirectional signal processing device placed in at least one of the input paths for preventing an output signal component from passing backward through one of the input paths to the other input path.
In the above embodiment, each of the unidirectional devices usefully comprises a buffer amplifier or other component of a signal splitter. Usefully, respective components of the mixer apparatus are implemented in CMOS or other suitable technology for use in a portable electronic device such as a wireless telephone terminal.
A further embodiment of the invention is directed to a method for mixing RF and local oscillator signals to provide an IF signal from which the image frequency signal has been rejected. The method comprises the steps of processing the RF signal to provide corresponding I and Q input signal components, and coupling the I and Q input components through first and second input paths, respectively, to first and second pluralities of switching devices in a configuration of switching devices. The method further comprises operating each of the switching devices to multiply its received I or Q RF input component with an I or Q component, selectively, of the local oscillator signal to generate I and Q mixer output signal components. A unidirectional device is placed in each of the switching device input paths to prevent an output signal component associated with one of the input paths from passing backward into the other input path.
It should be emphasized that the term comprises/comprising, when used in this specification, is taken to specify the presence of stated features, integers, steps, or components, but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding of the method and system of the present invention may be had by reference to the following detailed description when taken in conjunction with the drawings, wherein:
FIG. 1 is a schematic diagram showing a quadrature switching mixer of the prior art adapted for rejection of image signals;
FIG. 2 is a schematic diagram showing an embodiment of the invention;
FIG. 3 is a block diagram showing an embodiment of the invention used to provide an IF stage in a receiver; and
FIG. 4 is a schematic diagram showing components of the embodiment of FIG. 3 in further detail.
DETAILED DESCRIPTION OF THE INVENTION
Following is a detailed description of the invention with reference to the drawings wherein reference numerals for the same or similar elements are carried forward.
As mentioned previously, the present invention provides an effective and comparatively simple technique for substantially reducing leakage between the outputs of the I and Q branches of a quadrature switching mixer. Referring now to FIG. 1 , there is shown a quadrature switching mixer 10 of conventional design, wherein mixer 10 is capable of image signal rejection and is provided with quadrature input terminals 12 a and 12 b . Terminal 12 a is adapted to receive the in-phase input RF signal component RF I , and terminal 12 b is adapted to receive the quadrature input RF signal component RF Q , where RF Q (ωt)=RF I (ωt−π/2). Mixer 10 is also provided with I and Q output terminals 14 a and 14 b , which respectively provide I and Q mixer output signal components OUT I and OUT Q .
FIG. 1 further shows quadrature switching mixer 10 provided with commuting or commutating switches 16 - 22 , which respectively comprise pairs of complementary switches 16 a-b , 18 a-b , 20 a-b and 22 a-b . The input signal component RF I is coupled to switches 16 (i.e., 16 a and 16 b ) and 18 (i.e., 18 a and 18 b ) by means of input paths 24 a and 24 b . Similarly, input signal component RF Q is coupled to switches 20 (i.e., 20 a and 20 b ) and 22 (i.e., 22 a and 22 b ) by means of input paths 26 a and 26 b . An I component LO I of a local oscillator signal is also coupled to commuting switches 16 and 18 , and a component LO Q of the local oscillator signal is coupled to commuting switches 20 and 22 . The quadrature signal component LO Q is delayed 90 degrees relative to the in-phase oscillator signal component LO I . As stated above, each of the commuting switches is operable to multiply its received RF input signal component and its received local oscillator signal component. By providing each switch with complementary switches SW I and {overscore (SW I )}, or SW Q and {overscore (SW Q )}, the output signal from a switch is equal to the input signal to the switch when the non-complemented switch is closed, and the polarity of the signal is changed when the complemented switch is closed (i.e., OUT(t)=sgn {LO(t)}·RF(t)).
Referring still to FIG. 1 , there are shown the outputs of switches 16 and 18 coupled to a summing junction 28 a (Σ 1 ) and the outputs of switches 20 and 22 coupled to a summing junction 28 b (Σ Q ), to provide OUT I and OUT Q , respectively.
In accordance with the image rejection feature of mixer 10 , respective output components of the switches derived from the undesired image signal are cancelled out at the summing junctions.
In the prior art device shown in FIG. 1 , leakage can occur between the output signal components OUT I and OUT Q , via the RF inputs so that the output terminals 14 a and 14 b are effectively shorted together. For example, FIG. 1 shows a component L I of OUT I which may leak backwards to the RF I input, through switch 16 a , and then forward through the RF Q input and switch 20 a . Component L I could then be coupled forward through switch 20 a to output terminal 14 b . Similarly, a component L 2 of OUT Q may leak backward through switch 22 a and then move through the RF inputs to switch 18 a to become part of output OUT I .
Referring to FIG. 2 , there is shown a quadrature switching mixer 30 constructed in accordance with an embodiment of the invention. The mixer 30 is able to overcome the above output leakage problem of prior art devices, while at the same time perform image signal rejection as described above in connection with FIG. 1 . Mixer 30 includes switches 16 - 22 , terminals 12 a-b and 14 a-b and input paths 24 a-b and 26 a-b , which are identical or very similar to their respective same-numbered components shown in FIG. 1 .
Referring further to FIG. 2 , there is shown a mixer 30 provided with unidirectional buffer amplifiers 32 - 38 , respectively. The unidirectional buffer amplifiers 32 - 38 together form a signal splitter 40 , as described hereinafter in further detail. In accordance with embodiments of the invention, buffers 32 and 34 are inserted into input paths 24 a and 24 b , and thus receive the I input signal component RF I . RF I is coupled to switches 16 and 18 through respective buffers 32 and 34 , designated as B I+ and B I− . Similarly, buffers 36 and 38 , designated as B Q+ and B Q− , are inserted into input paths 26 a and 26 b . The quadrature input signal component RF Q is then coupled through the buffers 36 and 38 to switches 20 and 22 .
Since the buffers of the signal splitter 40 are unidirectional devices, they effectively prevent leakage between the I and Q branches of switching mixer 30 . That is, portions of output signal components OUT I and OUT Q cannot be connected backward to the input of the other branch. This reduces deterioration of the output signals provided by the mixer 30 and enhances conversion gain thereof. Accordingly, the quadrature switching mixer 30 may be readily used to take advantage of highly linear and low noise mixing characteristics, and at the same time provide efficient image signal rejection mixing.
Referring to FIG. 3 , there is shown the switching mixer 30 and the signal splitter 40 configured to serve as an intermediate frequency (IF) stage in a radio receiver. Such a radio receiver can be found in wireless devices such as mobile phones and the like that use UMTS, Bluetooth, and other wireless communication systems. The RF input signal is applied to a low noise amplifier (LNA) 42 , and coupled therethrough to the signal splitter 40 . The signal splitter 40 , described hereinafter in further detail, is operable to supply both the RF input components RF I and RF Q , which are respectively coupled to the mixer 30 .
Referring further to FIG. 3 , there is also shown an oscillator 44 generating the local oscillator signal LO, which is coupled to a phase shifter 46 . A square-wave drive of the local oscillator 44 may be desirable in order to improve linearity and noise performance. However, a square-wave drive is hard to achieve at RF; instead the local oscillator signal may be sinusoidal, with a large amplitude to steepen the slope of the wave form. A phase shifter 46 provides both the in-phase local oscillator component LO I and the quadrature local oscillator component LO Q . Phase shifter 46 usefully comprises an RC-CR network for generating the phase difference of 90 degrees needed to achieve the quadrature signal LO Q .
In FIG. 3 , component 30 a of the mixer 30 represents the commuting switches 16 and 18 and summing junction Σ I , which collectively produce the in-phase mixer output signal OUT I . Similarly, component 30 b of the mixer 30 represents the switches 20 and 22 and summing junction Σ Q , which collectively produce the quadrature output signal OUT Q . Accordingly, RF I and LO I are coupled to component 30 a , and RF Q and LO Q are coupled to component 30 b . FIG. 3 further shows mixer outputs OUT I and OUT Q coupled to buffer amplifier components 48 a and 48 b , respectively.
Referring to FIG. 4 , there is shown LNA 42 comprising inductively degenerated common-source stage M 5 , followed by a common-gate stage M 6 . The LNA design provides low noise, about 1.6 dB, at a low current consumption. Usefully, a 1.6 dB noise figure corresponds to a drain current of 800÷μA and an aspect ratio of 112÷μm/0.1÷μm (W/L). This low drain current implies that stage M 5 works near to the region of weak inversion, where the transconductance per unit of drain is at maximum, thus reducing the power consumption of the stage.
Referring further to FIG. 4 , there is shown the signal splitter 40 receiving the RF input, amplified by LNA 42 , to provide the in-phase signal component RF I and the quadrature signal component RF Q . FIG. 4 further shows splitter 40 coupling the RF I and RF Q components to mixer components 30 a and 30 b.
Components of splitter 40 located above voltage line V SS as viewed in FIG. 4 , and generally referenced collectively as 40 a , cooperate to provide the positive-phase input components. The splitter component 40 a acts as a current amplifier. It includes a common-source stage M 3 that is connected to a second stage involving two identical transistors, M 4 a and M 4 b , which provide two identical output currents. These output currents are fed back via two identical resistive networks, (R 2 a , R 1 a ) and (R 2 b , R 1 b ), to the input of the M 3 stage. The output of transistor M 4 a provides the RF I signal coupled to mixer component 30 a , and the output of transistor M 4 b provides the RF Q signal coupled to mixer component 30 b.
Signal splitter component 40 b comprises a configuration of components located below voltage line V SS as viewed in FIG. 4 , which is very similar to the configuration of splitter component 40 a . Splitter component 40 b provides the negative-phase input components which are coupled to mixer components 30 a and 30 b.
Switching mixer 30 is passive, double-balanced, and based on, for example, CMOS switches. FIG. 4 shows these switches realized as two complementary MOS transistors in pair, M 1 and M 2 . Thus, each of the switches 16 a-b through 22 a-b comprises a pair of switches M 1 and M 2 . The advantage with such a complementary switch, compared to a signal-transistor switch, is reduced on-resistance, which improves noise performance. In addition, charge injection from the local oscillator signals to the input signal and the output signal of mixer 30 is reduced. Moreover, because there is no DC current through the CMOS switches, flicker noise is reduced at the mixer 30 output. This consideration is particularly important in an embodiment with a low IF architecture, where low frequency is of concern. It should be noted, however, that other technology besides CMOS may also be used, such as BJT switches, without departing from the invention.
Referring further to FIG. 4 , there are shown buffer amplifier components 48 a and 48 b coupled to receive the outputs of mixer components 30 a and 30 b , respectively. Usefully, buffer components 48 a and 48 b are respective components of a single-stage transimpedence amplifier.
Obviously, many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the disclosed concept, the invention may be practiced otherwise than as has been specifically described. | A quadrature switching mixer is provided for mixing a received RF signal and a local oscillator signal, while rejecting an image signal associated with the RF signal. Input signal components in quadrature, that is, I and Q input components derived from the received RF signal, are respectively coupled through first and second input paths to corresponding commuting switches in a configuration of switches. Each of the switches operates to multiply respective quadrature components of RF and local oscillator signals to provide quadrature output signal components. A unidirectional device, such as a buffer amplifier included in a signal splitter, is placed in each input path to prevent any portion of an output signal component from leaking backward through one of the input paths to the other input path, and thus to the other output signal component. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is filed under 35 U.S.C. §120 and §365(c) as a continuation of International Patent Application PCT/DE2003/002749, filed Aug. 16, 2003, which application is incorporated herein by reference. This application also claims priority of German Patent Applications 102 40 031.8, filed Aug. 27, 2002, and 103 09 067.3, filed Mar. 3, 2003, which applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to transmission arrangements for motor vehicles in which engine torque is converted into a wheel axle torque and engine speed into a wheel axle speed and shift steps, torque converters, planetary gear sets, torsional vibration dampers, clutches and electric machines may be provided in the drive train.
[0003] Six and seven gear Lepelletier automatic transmission structures (six or seven forward gears and a single reverse gear) are known which are basically a particular combination of a simple planetary gear set with a Ravigneaux gear set. Ravigneau gear sets are well known gear sets that are used in 4-speed transmission blocks, i.e., four forward gear ratios and a single reverse gear. A known six gear Lepelletier automatic transmission is illustrated in FIG. 1 . Disposed in converter W, characterized by its main components pump P, turbine T and stator L, is a converter lockup clutch WK. The gear set comprises a planetary stage on the input side (3-shaft crank mechanism) and a Ravigneaux set (4-shaft crank mechanism) on the output side. Disposed between them are five wet-running clutches or brakes. FIG. 1 corresponds to the prior art of using wet, i.e., hydraulic, clutches and brakes.
BRIEF DESCRIPTION OF THE INVENTION
[0004] The parallel-shift transmission (abbreviated PSG), in accordance with the invention, having a twin-clutch transmission and at least one dry twin clutch, is a fully functionally alternative to the known converter transmissions in planetary design. By using dry clutches in the PSG, the oil pumps that are otherwise required may be eliminated, whereupon an outstanding overall efficiency is achieved with the PSG.
[0005] The object of the invention is to combine planetary gear sets with dry clutches or brakes as shift elements in order to combine the efficiency advantages of the dry clutches with the proven and simple configuration of planetary gear sets.
[0006] The transmission structures are to be provided according to the prior art with at least six forward gears and one reverse gear. In order to minimize the thermal stress of the dry starting elements, seven gear structures may also be used.
[0007] The core idea in the transition from wet clutches to dry clutches is that one divides the transmission into as few oil and dry chambers as possible. Located in the oil chambers are gears that are preferably lubricated by a churning lubrication. Located in the dry chambers are dry clutches or brakes and, at least in part, parts of the accompanying associated actuation system. When some or all of the wet clutches K 1 to K 3 (clutches 1 to 3 ) and brakes B 1 and B 2 (brakes 1 and 2 ) of prior art FIG. 1 are converted to dry clutches or brakes, not shown in FIG. 1 , advantages of the present invention are obtained.
[0008] More specifically the invention is a transmission arrangement, especially for motor vehicles, wherein the transmission arrangement is provided with at least one planetary gear set and a plurality of a combination of clutches and transmission brakes wherein at least one clutch or transmission brake is a dry clutch or transmission brake. Preferably a plurality dry clutches are provided wherein at least one dry clutch or brake is in operative connection with an electronic controller and is actuated thereby.
[0009] Preferably at least one planetary gear set is assigned to an oil bath on the bottom side of the bath and this planetary gear set is at least one of lubricated and cooled by churning oil lubrication. Control of shift operations may, however, be managed without an oil circulation.
[0010] Desirably, a dry clutch or brake is actuated by means of an electromotively driven mechanism.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention is explained in detail below with reference to the figures. The figures show:
[0012] FIG. 1 shows a Lepelletier transmission structure having a torque converter;
[0013] FIG. 2 shows a transmission structure having a dry chamber between two oil chambers;
[0014] FIG. 3 shows a shift state diagram for FIG. 2 ;
[0015] FIG. 4 shows a transmission structure having a starter-generator;
[0016] FIG. 5 shows a transmission structure having a twin clutch and a dry chamber between two oil chambers;
[0017] FIG. 6 shows a shift state diagram for FIG. 5 ;
[0018] FIG. 7 shows a transmission structure having a twin clutch, two separated oil chambers and a starter-generator;
[0019] FIG. 8 shows a transmission structure having only an oil chamber;
[0020] FIG. 9 shows a shift state diagram for FIG. 8 ;
[0021] FIG. 10 shows a structural design of the transmission structure of FIG. 8 ; and,
[0022] FIG. 11 shows a section from FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 represents a new transmission arrangement. if at least one clutch or one brake is operated in a dry manner, then the required amount of hydraulic fluid that must be transported via an oil pump Z (in the given case designed as a gear pump) is reduced. As a result, the required energy of the transmission arrangement is also reduced, whereupon at the same time the efficiency of the transmission arrangement increases.
[0024] In a further proposed solution ( FIG. 2 ), the transmission is characterized by a dry chamber (four shift elements) between two oil chambers in which a twin clutch (KDE, KDF) and a twin brake (BF, BG) is housed. The designation KDE here stands for a clutch that connects the D and E branches to each other. The same is true for the clutch position in which it connects the D and F branches to each other (=KDF). The designation BF stands for brake B, which brakes the F-branch. A corresponding situation applies for the designation BG. To the left in FIG. 2 , the designation KAG indicates that clutch K, which is illustrated there in the engaged state, connects branch A with branch G.
[0025] The twin clutch (KDE, KDF) connects the sun gears of the Ravigneaux set to the drive (planetary gear carrier) of the planetary stage on the input side. The combination of the two clutches in a twin clutch enables a compact and simple design. The same is true for the twin brake (BF, BG). A single clutch, which may be designed as in an automated shift transmission (ASG), having a torsional vibration damper (which may be designed as a dual-mass flywheel (ZMS); see also FIG. 5 ) is added between engine and transmission. The gear stepping and the shift scheme of the clutches and brakes are shown in FIG. 3 . The top part of FIG. 3 reproduces the schematic structure (in this case only the top part) of FIG. 2 .
[0026] FIG. 4 shows how one may expand this transmission with an electric machine as a starter-generator. A starter-generator is advantageous because it further reduces the fuel consumption of a vehicle, especially a motor vehicle. This electric machine enables connection to the planetary stage on the input side in a fixed gear ratio. Compared to a pure crankshaft starter-generator, this has the advantage that less torque is need for cold starting (because the ratio assists), which makes the dimensioning of the electric machine easier. In other words: due to the ratio, the crankshaft-starter-generator may turn out to be smaller.
[0027] The transmission variants of FIGS. 2, 3 or 4 can still be further improved: With only 6 gears, the drive ratio cannot be increased as desired, because otherwise the gear steps become too large. A 7 th gear would also be desirable. Furthermore, the structure with the e-machine does not offer the possibility of decoupling the internal combustion engine in the braking phases. As a result, the potential for decreasing fuel consumption cannot be optimally exploited.
[0028] FIG. 5 then shows the 7-gear transmission without an electric machine. The main feature, the dry chamber having a twin clutch and a twin brake included between two oil chambers, is retained. The designations KanG and KanA signify the operational positions of twin clutch K at branch G and at branch A, respectively. This usage is also applicable for FIGS. 6 and 7 . Located between engine and transmission is a second dry chamber having an additional twin clutch. The planetary gear carrier of the planetary stage on the input side may be coupled to the internal combustion engine or even be completely decoupled via the additional clutch. In this feature, this structure differs from the 6-speed Lepelletier automatic transmission, where one shaft of the planetary stage on the input side is always coupled to the crankshaft. The vibration isolation in the drive train may now be realized by slip control in the twin clutch on the input side (in connection with the depicted dampers in the clutch disks) or with a dual mass flywheel between engine and transmission.
[0029] FIG. 6 shows the shifting scheme for this transmission variant (= FIG. 5 ) and the ratios. In this context, an additional distinguishing feature from the 6-gear Lepelletier automatic transmission stands out: The 5 th gear of this transmission is a direct gear that, because it is direct, has an especially good efficiency.
[0030] The variant in FIG. 7 is this transmission structure, but expanded with an electric machine acting as a starter/generator. The electric machine is coupled via fixed transmission ratio to the planetary stage on the input side, in this case to the planet gears. For this structure, the additional clutch adds the advantage that now the electric machine may also be decoupled from the internal combustion engine. Thus, a switching-off of the internal combustion engine in the recuperation phases and a purely electric driving are possible.
[0031] The structural variant of a motor vehicle transmission in FIG. 8 is also a 7-gear transmission that is derived from the 6-gear variant of FIG. 2 or 3 . In this variant, it was a further goal of combining the two oil chambers in order to simplify the housing and to minimize the number of gaskets needed. In order to achieve this objective, the introduction of another planetary stage is necessary. The result is therefore a 7-shaft crank mechanism having two single planetary stages (single and twin-planet-gear steps) and a Ravigneaux set. Especially advantageous in this 7-gear transmission structure is the fact that 4 of the shift elements are brakes and only 2 are clutches (KAG, KGZ). Brakes (in this case BB, BC, BD, BG) are distinguished—in contrast to clutches—by a friction part being fixed to the housing and therefore not rotated, while the additional frictional part may be pressed close to the outer diameter, whereupon brakes may be operated in a much simpler manner, because they do not need a throwout bearing nor any mechanics from the throwout bearing for the pressing element. Within the context of this invention, brakes always have a “B” as the first letter and then only one additional letter that indicates the connection to the braked part (e.g., C, altogether therefore BC). Because with a brake an operative connection to the housing is always created, a third letter is not required to label this force flow.
[0032] The top portion of FIG. 9 shows the top half of FIG. 8 and is therefore a repetition. In the bottom half of FIG. 9 , on the other hand, a type of shift state table regarding the assignment of the gears to the clutches and brakes to be actuated is shown. Column i indicates the ratios within the transmission. The additional ratio through a differential is not taken into account in the number i. φ indicates the transmission ratio for the next lower gear. The negative sign for the reverse gear symbolizes the reverse direction. The numerical value (φges indicates the ratio of the 1 st gear to the 7 th gear. This ratio is also called stepping.
[0033] In the shifting state table of FIG. 9 , it is apparent that clutch KAG is not needed at all for starting off in first gear or for reverse gear, rather, clutch KAG is only used for gears 4 to 7 . Because the dual mass flywheel (ZMS) comprises two halves (namely, the primary and secondary side) and the clutch cover of clutch KAG is mounted on the secondary side of the dual mass flywheel, there is always a connection with the A-branch of the transmission. Via damper springs between the primary and secondary part, the A-branch (in FIG. 10 the innermost hollow shaft) is then also connected to the primary side, and thus with the internal combustion engine. If clutch KAG is engaged, then a force flow from the secondary side into central shaft 2 also occurs (see FIG. 10 ).
[0034] Although component KAG is not needed for the first gear or the reverse gear, the “clutch” designation is nevertheless justified because a clutch connects two rotating parts to each other. In contrast to this—as already explained above—in the brakes represented here BB, BC, BD and BG, each of the friction surfaces is connected to the housing of the transmission and thus are rotationally fixedly connected. Because of the preceding definitions, component KGZ is therefore also a clutch. According to the previous understanding of many experts, that component with which a drive train is engaged for starting off in first gear or in reverse is always a clutch. Through the language used in the invention, a new orientation of terms and ideas—even among experts—is necessary when applicable.
[0035] Furthermore, only a few selection and gear positions are discussed here in connection with FIG. 9 . It may be inferred here from the table, for example, that brakes BG and BC must be engaged for starting off in reverse gear. Brakes BB and BG must be engaged for starting off in the first forward gear. In other words: In order to start off—be it forward or in reverse—there must be braking in the transmission. There is another special shifting state with gear 5 . Through the indicated ratio i of 1 . 00 , it is clear that the engine speed is abandoned without changing the transmission. For this situation, none of the brakes is actuated; instead only the two clutches KAG and KGZ are engaged.
[0036] With FIG. 10 , a possible design of the transmission arrangement from FIGS. 8 and 9 is shown. It should be said first of the figures description that perimeter lines of the rotationally symmetric parts in this illustration were consciously left out essentially in order to guarantee clarity.
[0037] In a housing 1 , a central shaft 2 and an output shaft 3 that are disposed one behind the other extend in its longitudinal axis. Output shaft 3 essentially terminates in a drive flange 34 . The output shaft is mounted by means of a ball bearing 55 and a needle bearing 54 . Because needle bearing 54 is placed in a groove of output shaft 3 , it must be a two-piece design. In other words: Needle bearing 54 comprises at least two half shells, whereby it can be mounted in the groove of output shaft 3 . The left end of output shaft 3 is provided with a blind hole in which the right end of central shaft 2 is mounted by means of a needle bearing 54 . This mounting is required because—except in the fifth forward gear—in this case it comes between the two shafts, again relative to the direction of rotation. The left end of central shaft 2 is likewise guided via a needle bearing 54 . However, this needle bearing is located in a recess of a flywheel (not shown) or a crankshaft (not shown). One gets the impression from the previously sketched design of a transmission arrangement according to the invention that it could be unstable, because the left end of central shaft 2 is not guided before assembly of the transmission with the internal combustion engine. However, later in this description, it is explained that this stability is still there, likewise using ideas according to the invention.
[0038] Dual-mass flywheel 4 and clutch KAG also act on the left end of central shaft 2 . The dual mass flywheel comprises a primary mass 4 a that is screwed to the flywheel of the internal combustion engine. Primary mass 4 a is connected to secondary mass 4 b via an interior spring damping system. Because clutch KAG is connected to a first hollow shaft via its clutch cover 6 by means of a multi-point profile, a damping of the torsional vibrations is achieved even when a clutch KAG is disengaged. If clutch KAG is engaged—i.e. pressure plate 7 presses on clutch disk 64 —a force flow is also produced via clutch disk 64 by means of multi-tooth profile 36 into central shaft 2 . The engagement and disengagement of clutch KAG occurs in this exemplary embodiment via a disengagement system 5 , which essentially comprises a swivel shaft 52 mounted in bearing housing 1 , a pilot motor 56 having a worm gear and an eccentric. This eccentric presses on a sliding sleeve on which a throwout bearing 35 in turn is mounted.
[0039] If one then goes further to the right in the view of FIG. 10 , then additional hollow shafts disposed one over the other are shown in addition to the aforementioned first inner hollow shaft. The hollow shafts are each equipped—at least at one end—with a rolling bearing. The other end of this hollow shaft may be provided with a pure friction bearing.
[0040] However, an intellectual jump must first be made when viewing the transmission arrangement from left to right. A total of three planetary gears or planetary gear sets stand out in the center of housing 1 . The left planetary gear set 8 is a so-called single planetary gear set, that is, at least one planetary gear is disposed around the sun gear situated to the inside and this in turn engages in an interior gear situated to the outside. The sun gear situated to the inside is connected to a hollow shaft via a multi-point profile 41 . Located to the right is a so-called twin planetary gear set 9 . In the twin planetary gear set 9 , the sun gear is connected via a multi-point profile 42 to a hollow shaft. At least one planetary gear engages in the sun gear, but not in the accompanying interior gear. In a twin planetary gear set according to the invention, this aforementioned planetary gear meshes with another planetary gear, which is offset in relation to the focal plane. This additional planetary gear is then engaged with the internal gear.
[0041] Located to the right next to the twin planetary gear set 9 is a Ravigneaux planetary gear set 10 . Without going further into the details of the known Ravigneaux planetary gear set, it should nevertheless be mentioned that a Ravigneaux planetary gear set is equipped with two sun gears that have different diameters. The sun gears in this case are connected by means of a multi-point profile 43 and 44 to bowl-shaped or pot-shaped torque carriers.
[0042] The arrangement of the different torque carriers and the coupling of planetary gear sets 8 , 9 , 10 are discussed below. The planetary gear carrier of the single planetary gear set 8 along with the outer hollow shaft is connected by means of a multi-point profile 40 to the brake disk of brakes BD. This planetary gear carrier is in turn rotationally fixedly connected to a bowl-shaped torque carrier, which in turn is connected by means of the multi-point profile 43 to the larger sun gear of the Ravigneaux planetary gear set. The internal gear of the single planetary gear set 8 is also connected via a torque carrier to the planetary gear carrier of twin planetary gear set 9 . The sun gear of the single planetary gear set 8 is connected by means of multi-point profile 41 to a hollow shaft, which in turn is connected via a multi-point profile 39 to the brake disk of brake BC. The sun gear of the twin planetary gear set 9 is connected by means of multi-point profile 42 via a hollow shaft further to the inside, which in turn is connected via a multi-point profile 38 to the brake disk of brakes BB. The planetary gear carriers of twin planetary gear set 9 on its right side is also connected in turn to a hollow shaft, which in turn is connected by means of the multi-point profile 37 to clutch cover 6 . The interior gear of twin planetary gear set 9 is connected via a pot-shaped torque carrier by means of a multi-point profile 44 to the smaller sun gear of Ravigneaux planetary gear set 10 .
[0043] The Ravigneaux planetary gear set 10 is also in turn surrounded by pot-shaped torque carriers. The outer torque carrier in this case is connected by means of a multi-point profile 46 with both the brake disks of brakes BG and therefore also connected to the clutch disk of clutch KGZ. The inner torque carrier of the Ravigneaux planetary gear set 10 is connected to its interior gear as well as via a multi-point profile 45 to output shaft 3 . In Ravigneaux planetary gear set 10 there is a distinctive structural feature that a plate-shaped expansion of central shaft 2 is connected to the right end of the planetary gears—more precisely, to their bearing bolts—and these bolts are also simultaneously connected to a plate on the front face (on the left edge of Ravigneaux gear set 10 ). This plate on the front face is in turn connected to the outer, pot-shaped torque carriers. The entire area of the transmission arrangement in which the planetary gear set is located is oiled and cooled by an oil churning lubrication. In order for bordering, so-called dry areas not to come into contact with the oil, intermediate plates 50 and 51 are located there. These intermediate plates are sealed from housing 1 —that is, a likewise stationary part—by means of, for example, an O-ring. Present between each of the intermediate plates 50 and 51 and rotating parts (shafts and hollow shafts) is a shaft sealing ring, such as a radial, lip-type sealing ring. The shaft sealing ring is labeled with an arrow, the arrow direction indicating the preferred blocking direction.
[0044] Because the individual gears are in the transmission according to the invention, in planetary gear sets 8 , 9 and 10 , and these gears need at least an oil lubrication and cooling on their tooth flanks, an oil chamber, which is filled with oil up to oil-fill height 63 , is mounted below the planetary gear set. By immersing at least the Ravigneaux planetary gear set 10 , oil is swirled, whereupon the other planetary gear sets are also covered with oil. Because the planetary gear sets are surrounded by the pot-shaped and bowl-shaped torque carriers, it is advantageous if these torque carriers are partially perforated so that the oil can better get to the tooth flanks and the bearings.
[0045] Because in the transmission arrangement according to the invention two shafts, a plurality of hollow shafts and bowl-shaped and pot-shaped torque carriers are nested inside each other and these nested components have a connection to oil chamber 61 , oil can come on the left side from intermediate wall 50 or on the right side from intermediate wall 51 at the relevant places for the discharge of the oil. For this reason, shaft sealing rings are then applied there.
[0046] The shifting of gears in the transmission arrangement according to the invention can be managed using different devices. In connection with clutch KAG, a disengagement system 5 was already described. Instead of swivel shaft 52 and pilot motor 56 (in this case with a worm gear), a stationary bearing surface may also be arranged on the right side of throwout bearing 35 , so that a master cylinder may be arranged between throwout bearing 35 and this stationary bearing surface, as is known, for example, from automatic transmissions having electronic clutch management. The associated hydraulic circuit and the master cylinder could then be disposed, for example, outside of the housing, where there is enough space.
[0047] For clutch KGZ and brakes BB, BC, BD and BG, other paths were followed. With brake BB, the brake disk is positioned between two pressure plates 21 and 22 . Pressure plate 22 is firmly bolted to housing 1 . Pressure plate 21 is axially displaceable. If it is pressed toward the right, then the brake disk is clamped between it and pressure plate 22 . The movement of pressure plate 21 is effected by a pilot motor 57 —in this case with a bevel gear—which turns a disk about the central shaft 2 . This disk is characterized within the context of this invention as ring lever 20 . Why the name was selected becomes clear from the following description. Located on the right side of ring lever 20 is a spiral crank 18 , this spiral containing a plurality of windings of a groove. Located in this “record groove” is a plurality of displaceable balls 19 . Ring lever 20 is itself also ball-bearing supported opposite housing 1 . If there is then driving via pilot motor 57 in the corresponding direction, then displaceable balls 19 move either further inward (in the direction of central shaft 2 ) or further outward. These displaceable balls 19 act on another lever, which in turn acts on pressure plate 21 . Another wear setting 11 may also be arranged between this lever and pressure plate 21 . What is decisive in this approach is that the displaceable balls 19 are pivot points for a lever system. If displaceable balls 19 were brought to a position that is situated radially far inward, then an energy accumulator 14 (for example, designed as a diaphragm spring) exerts its force on a correspondingly long lever arm so that a high force may be exerted at the short lever arm on pressure plate 21 . This high force in turn leads to brake BB being engaged. In order to prevent a rotary movement of pressure plate 21 and also in order to give pressure plate 21 a guide in the non-clamping state, it is connected with pressure plate springs 53 to housing 1 .
[0048] Also brake BC acts on pressure plate 22 if it is engaged. The difference is just that the brake disk of brake BC in this case must be pressed to the left. For the pressing, pressure plate 23 must be axially moved to the left. In order for it to be possible to move pressure plate 23 to the left, and adjustment must be made between an abutment 48 and pressure plate 23 using an adjustment mechanism. This adjustment is performed in this case via a pilot motor 58 , which acts by means of a worm gear on rolling bodies, which may then be displaced around the perimeter. Moreover, another energy accumulator 15 and a segmented ring lever 31 are located between pressure plate 23 and the rolling bodies (preferably slightly tapered). This segmented ring lever 31 is depicted in a small section above the main figure. Each individual segmented ring lever 31 is connected by means of an elastic bar 32 to a retaining ring 33 . Indicated in the section are also the rolling bodies on which the segmented ring lever 31 rolls off, whereby in this context a pivot point is in turn changed and as a result the ratio of load to lever power arm is changed again. If a certain swivel situation is achieved for the segmented ring lever, then prestressed energy accumulator 15 (in some cases designed as a diaphragm spring) can unleash its tensioning force and in so doing press pressure plate 23 against the brake disk of brake BC.
[0049] Pilot motor 59 is driven for the actuation of brake BD. The mechanism shown for this corresponds to the one for brake BC and is symmetric to abutment 48 . Therefore, a further description may be omitted here.
[0050] It is common to pressure plates 21 , 22 and 23 in the figure that they are equipped with cooling water channels 65 . In this context a design of the cooling water channels 65 is especially advantageous, in which the channels—relative to the depicted pressure plate width—are centrally arranged and also penetrate the pressure plate bodies in the form of chords of a circle. These channels may be produced for example by bores. In a front graphical view, the channels then depict a polygon whose corner points lie within the area of the annulus. The beginnings of the channels situated radially to the outside are then either sealed—for example, by means of a caulked ball—or designed as intake and discharge. The connections for the intake and the discharge may be flexibly configured—such as a hose or corrugated metal tubing—in an area near the pressure plate and then conducted within a rigid line. It is advantageous then if the intake and the discharge are situated diametrically opposed so that a good flushing with cooling water is possible. It is especially advantageous if, in this case even several intakes and several discharges are designed. In another embodiment of the invention, the cooling water may be drawn from the cooling line of the internal combustion engine. However, a separate cooling line may make sense for the pressure plates if, for example, the motor vehicle is equipped with a starter generator, and, during its partially exclusive operation, the cooling devices of the internal combustion engine are not available, or not sufficiently available.
[0051] On the other hand, the braking mechanism for brake BG or for clutch KGZ represents another technical solution. Brake BG in this example comprises a total of two brake disks. These are required in order to reliably absorb the braking moment occurring at them. At first glance, it is irritating that the brake disk of clutch KGZ is arranged along with its multi-point profile 46 on the same component, namely the outer torque carrier of Ravigneaux planetary gear set 10 . If one looks at the shifting state diagram of FIG. 9 , one determines that clutch KGZ is only needed in fifth gear. Brake BG, on the other hand, is operated in reverse gear and in first gear. Although now KGZ and brake BG must be shifted in different situations—that is, not simultaneously—it is possible to engage, for example, brake BG (and thereby disengage clutch KGZ) by means of the device that is driven by pilot motor 60 in connection with a worm gear without causing an interruption of the drive train or a forced state.
[0052] In order to show this mechanism more clearly, a sectional enlargement of this area of FIG. 10 has been drawn, which is represented in FIG. 11 . In this figure, the two brake disks of brake BG, the clutch disk of clutch KGZ and pressure plates 26 , 27 , 28 , 29 and 30 may be seen afresh in their geometry and their arrangement. Pressure plate 30 in this case may also be seen with its connection to output shaft 3 and parking gear 49 . A torque carrier may be seen at the left edge of the figure, which is connected by means of multi-tooth profile 45 to output shaft 3 . This torque carrier is connected to the sun gear of Ravigneaux planetary gear set 10 . The extension on the right side of the outer torque carrier of Ravigneaux planetary gear set 10 is provided with multi-tooth profile 46 , which rotationally fixedly couples the brake disks of brake BG and the clutch disk of clutch KGZ in the manner already described.
[0053] Intermediate plate 51 transitions into a toothed, circumferential pot profile 66 . This pot profile 66 may, for example, have been welded to intermediate plate 51 after its production. However, intermediate plate 51 and pot profile 66 may also advantageously be produced in one piece via reshaping (e.g. deep drawing). Toothed pot-shaped profile 66 is also advantageous because, as a result of it, pressure plates 26 , 27 and 28 may be supported via their likewise circumferential, toothed profiling in pot-shaped profile 66 . If housing 1 in the area that faces pot-shaped profile 66 is likewise profiled, then the reaction forces of brake BG may be supported at housing 1 .
[0054] What is decisive about FIG. 11 is the mechanism with which it is possible to shift alternately back and forth between an engaged brake BG and an engaged clutch KGZ. The changeover occurs via a crank 12 that has a plurality of spiral segments. The arrangement of the segments may be derived from a section of FIG. 10 . A right-hand, front wall 74 is welded, for example, to pot-shaped profile 66 . Located in this wall are, for example, radial slots in which a pin for a guide carriage of a roller 13 can slide. Roller 13 is supported in this context on the inner side of wall 74 . Slots are also placed in an annular lever 71 , so that roller 13 can dip into these slots. A needle bearing is preferably disposed between roller 13 and its shaft 13 a. This is advantageous because shaft 13 a —which is wider than roller 13 —can roll off the outer side of lever 71 without rotary movements of roller 13 relative to shaft 13 a being hindered. An energy accumulator 17 —which is designed here as a diaphragm spring—engages with its outer end in toothed pot-shaped profile 66 . The inner end of energy accumulator 17 is bent and via the pretensioning of energy accumulator 17 presses this end against lever 71 . The outer and inner circumferences of energy accumulator 17 are surrounded with a plurality of slots. If roller 13 is located radially to the outside, then there is pressure via a sleeve 67 on pressure plates 26 , 27 , 28 and the brake disks situated between them. Brake BG is then engaged.
[0055] If roller 13 is then moved toward output shaft 3 by means of crank 12 and pilot motor 60 (see FIG. 10 ), which is provided with a worm/worm gear connection to crank 12 , then on the one hand the pressing force on brake BG is gradually reduced, and at the same time via lever 71 a force is increased on the axially displaceable groove ball bearing, whereupon the engagement force for clutch KGZ is correspondingly increased on annular lever 72 . Lever 72 is mounted by means of two wire rings 69 arranged on opposite sides and guided by stud bolts 73 .
[0056] Lever 72 engages in an essentially annular bracket 68 . The left edge of this bracket 68 encompasses pressure plate 29 . The right edge is configured graduated in the axial direction so that an inner right edge includes the right edge of pressure plate 30 . The radially outer end of lever 72 engages in the outer right edge of bracket 68 . If this end then inclines to the right—due to the movement of roller 13 toward output shaft 3 —then pressure plates 29 , 30 gradually approach one another and pressure plates 26 to 28 are unloaded. The more roller 13 then moves radially inward—thus, clearly past the point at which the bent end of the energy accumulator rests against lever 71 —the stronger the unloading of brake BG and the engagement of clutch KGZ.
[0057] If, via the aforementioned mechanics, roller 13 is moved radially outward, then the movement sequence reverses and brake BG, rather than clutch KGZ, is engaged. The mechanism for brake BG and clutch KGZ is a mechanical realization of an EXOR link with a flowing transition. The design is also very advantageous in this respect, because two shift elements (clutch KGZ and brake BG) may be operated at the same time with only one pilot motor 60 may be operated. However, this may only be applied in the present design because KGZ and BG never have to be simultaneously operated.
[0058] As was already mentioned of FIG. 10 in connection with clutch KGZ, the disengagement of throwout bearing 35 via a positioning motor 56 or via a slave cylinder in connection with a control unit is very advantageous. This is especially true if all pilot motors 56 - 60 are controlled by a common controller and a common program. As a result, shift points for the gears, the shifting behavior of the transmission overall (sport, defensive), may be affected with—or without—a pulling force interruption, and many other parameters may be affected just via programs. | The invention relates to a transmission arrangement, particularly for a motor vehicle, comprising at least one set of planetary gears and at least one dry clutch or a dry transmission brake. The inventive transmission arrangement allows advantages of the automatic transmission to be combined with the energy-saving clutches and transmission brakes. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an apparatus and method for use in construction of a press box. Press boxes are typically employed at football, soccer, track or racing stadiums. More particularly, though not exclusively, the present invention relates to an apparatus and method for constructing such press boxes in modular fashion.
[0003] 2. Problems in the Art
[0004] As is noted in U.S. Pat. No. 6,457,281 to Teron, the construction industry has been relatively slow in adopting new and developing technology. Generally, the construction industry has remained very labor intensive and of a handicraft nature. The end result is that construction projects are still expensive endeavors in terms of both money and time.
[0005] The Teron patent, mentioned above, attempts to overcome the labor and time intensive nature of the construction industry through the use of pre-cast concrete monolithic units. While such units can be cast in a variety of shapes and sizes, each casting forms a solid structural wall that is not easily prone to adaptation. For example, the use of windows or doors requires separate in-fill panels as such cannot be readily integrated into a pre-cast structure of concrete. Therefore, it is desirable to have a modular building system in which various wall structures, including doors and windows, can be easily added.
[0006] In the world of spectator events, press boxes are ideally located above the area of action. For example, in a high school football field setting, the press box is usually situated to one side of the field above all of the bleachers. Many press boxes also have more than one level from which to view the activity of interest. For these and other reasons, it is desirable to have modular units which are stackable without the need for additional supporting structures.
[0007] Whether a press box is used for a football, soccer, track, or other sporting event, several common features are desirable. For example, every press box will need some sort of viewing area as well as a plurality of counters, tables, chairs and other features typically used by the occupants thereof. Because the features of the press box do not tend to vary greatly whether the press box is used for football, soccer, or in conjunction with any other sporting arena, it is desirable to have a modular unit for constructing press boxes that easily incorporates many of the standard and desirable features of press boxes in use today.
[0008] Many arenas in use today are built with the assistance of public funds. Public funding is typically only awarded after a bidding process. During the bidding process, price, efficiency, and quality of the end product are of prime concern. It is therefore desirable to be able to offer a press box and method of constructing the same that minimizes production costs, increases production efficiency, and can be easily adapted to accommodate all of the customers demands. There is therefore a need for an apparatus and method of constructing a press box which avoids these and other problems.
[0009] Features of the Invention
[0010] A general feature of the present invention is the provision of an apparatus and method for constructing a press box which overcomes the problems found in the prior art.
[0011] A further feature of the present invention is the provision of an apparatus and method for constructing a press box which is easily adaptable for use in many different arenas.
[0012] Another feature of the present invention is the provision of an apparatus and method for constructing a press box which allows the press box to be easily customized for any particular customers desires.
[0013] A still further feature of the present invention is the provision of an apparatus and method for constructing a press box, which allows the press box to include windows, doors, balconies, benches, seats and other features at a variety of locations.
[0014] A further feature of the present invention is the provision of an apparatus and method for constructing a press box, which uses modular units.
[0015] Another feature of the present invention is the provision of an apparatus and method for constructing a press box which incorporates modular units that are stackable.
[0016] A still further feature of the present invention is the provision of an apparatus and method for constructing a press box which simplifies the on-site construction process.
[0017] Another feature of the present invention is the provision of an apparatus and method for constructing a press box which minimizes assembly time.
[0018] A still further feature of the present invention is the provision of an apparatus and method for constructing a press box which minimizes construction costs.
[0019] Another feature of the present invention is the provision of an apparatus and method for constructing a press box which allows additions to be made to existing structures easily.
[0020] These, as well as other features and advantages of the present invention, will become apparent from the following specification and claims.
SUMMARY OF THE INVENTION
[0021] The present invention generally comprises an apparatus and method for constructing a press box through the use of a plurality of press box modules. In one embodiment, a plurality of press box modules are formed offsite. Each press box module generally includes a box-like frame having a number of structural supports built therein. Preferably, each press box module is of a standardized size and shape such that one module may be easily stacked upon another module in a block like fashion.
[0022] When assembled, each module preferably includes a plurality of steel columns or steel tubes at its corners. The steel columns are connected to one another by steel beams which may be secured to the columns through welding, screws, or any other well known method. Each column is preferably topped with a connector plate that acts as both a supporting platform and a means for connecting various modules in a vertical arrangement. Each module also includes a plurality of side beams that provides structural support. Each beam is preferably half of an I-beam or generally C-shaped. This presents the outer edge of the module with a flat surface. By keeping the outer surfaces flat, beams in different modules can be easily connected by including a plurality of corresponding holes in each beam and securing the beams there through. Securement can be performed with nuts and bolts, welding or any other known securing means.
[0023] In another embodiment, construction is further simplified by using steel tubing for both the columns and beams. The added strength associated with the use of steel tubing allows construction of the modules to be done with minimal reinforcing materials. This allows for an open cross-section and thereby provides limitless opportunity for walk ways, placement of doors, windows, benches, electrical fittings and other desirable interior appointments. Using a plurality of steel tubing also minimizes the variety of materials needed, allowing for increased efficiency in both ordering and construction. These modules, formed primarily of steel tubing, can be secured to one another using welding, nuts and bolts or any other known securing means.
[0024] Using either of the above mentioned embodiments, the modules can be rapidly assembled and stacked to form a press box of any desirable shape or size. Because easily modifiable framing elements are used instead of pre-cast structures, various elements are easily added to a press box module. For example, door jambs can be created using L-arm structural steel members, aluminum framing, or wood. In a similar fashion, window sills can be arranged to accommodate a variety of window sizes and shapes without the need to alter the pre-existing box frame. Each of these elements may be secured to the box frame through tack welding of the pieces directly or of suitable connector pieces.
[0025] Each box frame also preferably includes flooring at a pre-determined and consistent level in each box frame. The flooring is generally formed from a plurality of flooring joist secured between the flooring beams by plurality of connector tabs. The flooring joist may be made of wood or metal or even adapted to support concrete slabs. In a similar manner, ceiling joist preferably run along the top of the box frame.
[0026] After the flooring construction is completed, a variety of built-in componentry can be added. For example, if the customer desires a countertop underneath the window or viewing area, a counter can be pre-installed. Additionally, electrical conduit including a plurality of electrical boxes and switchboxes at desired locations may be inserted before wall finishing is completed
[0027] On the top of the uppermost press box module, it is typically desirable to include a roof structure. The roof structure or roof module may be formed from either a column and beam or the steel tubing arrangement. In the column and beam arrangement, the roof module preferably includes a plurality of connector plates corresponding to the connector plates on the top of the press box module. This allows for nut and bolt connections to be easily made. Alternatively, in the steel tubing arrangement, the roof module may be easily welded to the tubing of the press box module below. Either arrangement can be secured together and to the corresponding box module below using any known method.
[0028] Pre-assembling the roof module allows it to be easily connected with minimal onsite customization. Each roof module may include a roof that is angled at a pre-determined level and generally includes a plurality of roofing beams or additional tubes having connector tabs secured thereto. Between the roofing beams or tubes are a plurality of roofing struts that support the actual roofing material. By connecting the roof beams or tubes between two roof columns or additional tubes of varying heights, the roof angle can be controlled.
[0029] Additional structures may be added to the outside of the press box modules, including a staircase for upper level access, and balconies if outdoor viewing is desirable. Both the balconies and the staircases may be easily bolted or otherwise connected to each press box module as desired. Balconies may be preinstalled before all of the modules are assembled into the final press box. Once modules are assembled or stacked, a balcony accessible in one module may be supplementally supported through a beam connection to a lower module. Additional structural supports may be used throughout the modules, including gusset plates with corresponding bracing rods. These keep the modules in tension and therefore minimize the amount of structural flex that may be inherent in each box frame.
[0030] Once all of the individual modules are assembled, standard finishing materials such as drywall, carpeting, lighting, etc. may be applied to give the interior of the press box the desired appearance. Further, after module assembly is complete, siding material may be added to give the outside of the press box a finished appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The various features and advantages of the invention will become more apparent from the following description of the preferred embodiments of the same wherein references made to drawings including:
[0032] [0032]FIG. 1 is a perspective view of one embodiment of the modular press box in assembled form as would be installed at an arena.
[0033] [0033]FIG. 2 is a front view of the press box module assembly of FIG. 1.
[0034] [0034]FIG. 3 is an exploded view of one embodiment of the press box module assembly showing individual modules separated from one another.
[0035] [0035]FIG. 4 is an exploded view of another embodiment of the press box module assembly showing individual modules separated from one another.
[0036] [0036]FIG. 5 is a side view of a typical roof tube, ceiling tube or flooring tube to which connector tabs have been installed.
[0037] [0037]FIG. 6 is a cross-sectional view of the sidewall of one embodiment of a press box module in finished form.
[0038] [0038]FIG. 7 is a cross-sectional view of the connection between one embodiment of the roof module and one embodiment of the press box module.
[0039] [0039]FIG. 8 is a cross-sectional view of one embodiment of the flooring installed in a press box module.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Referring now to FIG. 1, there is illustrated a perspective view of the modular press box 10 installed in conjunction with a series of bleachers 12 at a stadium 14 . The press box 10 is preferably made from a variety of steel structures, including steel tubes, beams, columns, L-arm members, plates, brackets, rods, etc. Alternatively, other materials, such as aluminum, wood, composites, or plastic materials may be substituted as desired so long as the strength and integrity of the press box 10 is not compromised. As is shown in FIG. 1, the press box 10 is built up of a variety of press box modules 16 . The modules 16 may be arranged to provide an elongated structure with one or more floors as shown.
[0041] A typical press box 10 is placed in an elevated position to allow the members of the press, announcers, coaching staff, and other individuals the desired advantage point. Any number of press box modules 16 may be used until the desired height is reached. Alternatively, the press box modules 16 and the press box 10 in its entirety may be elevated on a supporting platform or base structure, so long as the desired advantage point is reached. A preferred supporting platform (not shown) is constructed of steel beams or columns which are reinforced using a plurality of gusset plates and bracing rods. As the typical vantage point is an elevated one, stairs 18 may be secured to one or more press box modules 16 so that access to the press box 10 may be had from ground level. Alternatively, an elevator (not shown) may be assembled and secured as desired.
[0042] Referring now to FIG. 2, each press box module 16 may include a balcony 20 secured thereto. Each press box module 16 may be designed to include its own balcony 20 , to have no balcony 20 , or to have a balcony 20 that connects with the balconies 20 of other modules 16 . Also shown in FIGS. 1 - 4 are a plurality of roof modules 22 . By stacking the individual press box modules 16 in the desired arrangement and securing roof modules 22 on the uppermost press box module 16 , the desired final shape of the press box 10 can be realized.
[0043] As many sporting events have a very limited off-season time period, it is desirable to keep on-site assembly time to a minimum. By using preformed press box modules 16 in conjunction with preformed roof modules 22 , on-site assembly time can be easily managed and minimized. Thus, a module press box 10 can be easily assembled during the off-season time available causing minimal inconvenience to the purchasing customer.
[0044] As is shown in FIGS. 3 and 4, each of the modules 16 may be formed by creating a box-like frame structure. For example, FIG. 3 illustrates that square steel tubing, preferably ¼ inch think, 8 inch by 8 inch steel tubing, is using to form a plurality of columns 24 placed at the corners of the box-like frame structure. Each of the columns 24 are connected to one another through the use of a plurality of beams 26 . The beams 26 are preferably generally C-shaped as shown. A cross-sectional view of one such beam 26 is shown in FIG. 6.
[0045] Additionally, beam support brackets (not shown) may be secured between the beam 26 and the column 24 to provide additional structural strength if needed. The support brackets are preferably steel plates that are simply welded in place once the beam 26 has been secured to the column 24 . The beam 26 may be secured to the column 24 through welding, bracketry, or any other known method. Additionally, when it is known a customer will not desire to passthrough the beam 26 and column 24 arrangement, i.e. that it will be a solid wall, additional bracing materials may be employed. For example, as shown in FIG. 1, a plurality of gusset plates 32 are secured to the corners of the beam 26 and column 24 assembly. A central gusset plate 32 allows a plurality of bracing rods 30 to be connected to enhance the rigidity of the overall wall formed by the beams 26 and columns 24 .
[0046] In another embodiment of the present invention, the press box module 16 using steel tubing 25 in place of the columns 24 and beams 26 as shown in FIG. 4. Using 8 inch by 8 inch {fraction (1/4)} inch thick steel tubing allows for construction of press box modules 16 without the need for additional bracing materials. This arrangement maximizes the interior space of the press box module 16 while minimizing construction time and cost.
[0047] A wall formed by either the beams 26 and columns 24 , as shown in FIG. 3, or the tubing 25 , as shown in FIG. 4, may also be fitted to include a variety of additional elements. For example, as shown in FIG. 4, a doorjamb 34 has been installed. The door jamb 34 generally includes a plurality of L-arm or other bracketry 40 arranged to accommodate the desired door size. The doorjamb 34 is generally made by using a header 36 and retaining member 38 which can be spot welded into place or alternatively screwed into the tubes 25 or beam 26 and post 24 . Alternatively, the bracketry 40 can be arranged merely to accommodate the desired opening between rooms in the press box 10 .
[0048] Typically one module will become one room in the press box 10 . However, the open wall provided by the beam 26 and column 24 arrangement or the tube 25 arrangement, allows multiple modules 16 to be assembled to form one room. Alternatively, rooms may be broken up in any desired fashion.
[0049] Additionally, other features may be added to the press box module 16 . A counter 42 , shown in FIGS. 3 and 6 may be installed in any desired location. As is shown in FIG. 6, it is usually desirable in a press box 10 to have a counter 42 close to a window 52 . The counter 42 can be secured directly to the flooring 58 such that the countertop 56 abuts against the window wall. As is also shown in FIG. 6, the flooring 58 is generally secured to the beam 26 through the use of an L-arm bracket 40 . The L-arm bracket 40 is preferably a steel member that is supplementally supported through one or more support tabs 66 , generally shown in FIG. 5.
[0050] Referring again to FIG. 3, electrical conduit 46 as well as corresponding electrical boxes 48 and switch boxes 50 may be placed as desired throughout the box-frame structure of any press box module 16 . Preferably, the electrical and countertop work is not performed until the floor 58 has been formed.
[0051] The floor 58 is generally secured in the same manner as the deck or balcony 20 . As is shown in FIG. 6, the flooring 58 or balcony 20 is formed by initially welding a plurality of support tabs 66 to the inside of C-shaped beam 26 . Next, an L-arm bracket 40 is welded or otherwise secured to the beam 26 and support tabs 66 . Preferably, an aluminum deck structure or concrete slab 58 is secured to the L-arm brackets 40 through the use of a puddle weld, cement screws or other securing means. When this arrangement is to be used for a flooring section, the aluminum deck or concrete slab 58 provides a solid surface over which carpet, tile, or other desired flooring material may be placed. As is also shown in FIGS. 3 and 4, flooring support joists 80 may be secured in a similar fashion. The flooring beams 82 , also the bottom beams 26 or bottom tubes 25 , may be fitted with a plurality of flooring connector tabs 84 to accommodate a plurality of transversely placed flooring joists 80 . The flooring connector tabs 84 are preferably secured to the flooring beams 82 or bottom beams 26 or tubes 25 through welding, though any other securing method may be used.
[0052] Preferably, the flooring tabs 84 have a plurality of holes therein that correspond to a plurality of holes in the flooring joists 80 . This allows the flooring joists 80 to be rapidly assembled into proper position using nuts and bolts, though any type of securing method may be used. The flooring joists 80 thereby provide additional support to the decking or flooring material 58 previously discussed. Ceiling joists 86 may be similarly installed between ceiling beams 88 , the upper most beams 26 or upper most tubes 25 , using ceiling connector tabs 90 .
[0053] Alternatively, the flooring 58 may be secured on top of I-beam flooring joists 80 and the flooring beams 82 made from bottom tubes 25 as is shown in FIG. 8. The shape of the steel tubing 25 provides for additional support for the flooring 58 eliminating some of the additional supports required for the beam 26 and column 24 arrangement. A C-channel member 83 having a flat outer edge may be place to meet the end of the flooring 58 . This provides a finished outer surface that may be easily adapted for finishing materials.
[0054] Referring again to FIG. 6, a window 52 may be installed into a wall of the press box 10 by employing smaller C-shaped steel bracketry to form a window seal 44 . Wood framing 54 may be used to ensure a weather tight fit of the window 52 . Again, the open area format of the beam 26 and column 24 wall arrangement or the tube 25 wall arrangement allows a wide variety of shapes and sizes for the window 52 . Once the window 52 has been installed, closure plates, typically provided by a siding supplier, can be employed to ensure the wall is weather tight.
[0055] During assembly of the beam 26 and column 24 arrangement of the individual press box modules 16 and referring to FIG. 7, a plurality of connector plates 70 are preferably placed on the upper and lower portions of the columns 24 or at other alternative locations as desired. Preferably, the connector plates are 14 inch square, ¼ inch thick steel plates that have a plurality of holes therein. Each connector plate 70 is identical such that the connector plates 70 from one module 16 may easily align with the connector plates 70 of another module 16 . In order to minimize assembly time and ease installation, the connector plate 70 are substantially larger than the cross-sectional area of the columns 24 . It is in this access area that hangs over the column 24 , that holes may be placed.
[0056] As is also shown in FIG. 7, when the roof module 22 or any other module 16 is formed in the beam 26 and column 24 arrangement, they may be assembled by matching up the holes in the connector plates 70 and securing the upper connector plate 70 to the lower connector plate 70 with a plurality of bolts 64 and nuts 62 . As is also shown in FIG. 7, the column 24 may include an additional bracket or gusset plate 32 to which bracing rods 30 may be installed as previously discussed. This allows the columns 24 to put pressure on the beams 26 , thereby strengthening the overall rigidity of the entire box-frame press box module 16 .
[0057] As the connector plates are used to secure the various press box modules 16 together in a vertical arrangement, so the beams 26 can be used to secure the press box modules 16 in a horizontal arrangement. As is shown in FIG. 7, the beams 26 of the press box module 16 include a plurality of holes through which bolts 64 and nuts 62 can be secured.
[0058] Alternatively, when the tube 25 arrangement of the press box module 16 is used, the modules may be simply stacked on top of one another or side by side and then they are preferably welded together, preferably using a {fraction (1/4)} inch stitch weld every 2 inches. Any other connection means including welding, screws, etc. can be employed to secure one press box module 16 to another press box module 16 in a vertical arrangement. Thus, it can be seen how the various press box modules 16 can be added to form a press box 10 of any shape or size.
[0059] As is shown in FIG. 3, the roof module 22 , consists generally of two pairs of roof columns 76 . One pair of roof columns 76 is at a pre-determined height with the other pair of roof columns 76 being at a slightly greater height. In this manner, the roof module 22 can have a roof of any desired slope. In between the roof columns 76 , roof beams 74 are placed. As is shown, the roof beams 74 are similar to the ceiling beams 88 and flooring beams 82 in that a plurality of connector tabs 78 are welded thereto. The outer ends of the roof beams 74 have been mitered to correspond with the desired slope of the roof. In between the roof beams 74 are a plurality of roofing struts 72 . The roofing struts 72 are secured to the connector tabs 78 through the use of screws, bolts and nuts, welding, or any other connective means.
[0060] Alternatively, the roof module 22 may be formed using steel tubes 25 as is shown in FIG. 4. The roof columns and beams are formed of steel tubes 74 cut to the desired length and angled or mitered to provide the desired roof shape. As is shown in FIG. 5, the connector tabs 78 are placed on the tubes 25 in the same manner as the connector tabs 84 and 90 for the flooring and ceiling respectively.
[0061] After each of the press box modules 16 are completed in the desired fashion and assembled to form the press box 10 , finishing materials, such as carpeting, siding, insulation, drywall, paint, wallpaper, lighting, etc. may be installed according to the customer's specifications. The manner of installing all of these elements over an existing steel frame structure is well known in the art.
[0062] By making the internal framework in modular form, the entire process may be expedited while still providing the customer with a high quality, customizable end product. It is preferred that the individual press box modules 16 are prefabricated as much as possible at the shop or first location. This would include building in almost all of the electrical systems, heating and ventilation systems, flooring systems, doors, benches and countertops as desired. Once assembly of the individual press box modules 16 is completed to the extent possible, the modules are transported to the construction site or second location. Preferably, the modules 16 are loaded onto a semi-truck trailer for transport. By using the box-frame styles mentioned herein, the size of the individual press box modules 16 can be limited to the height and width allowed to travel down interstate highways without the need for special permits or warning vehicles.
[0063] At the construction site, the individual modules 16 are unloaded and placed into the desired position. They are then secured together as previously discussed and staircases 18 , balconies 20 , and other exterior appointments are added. The roof modules 22 are added and the exterior finishing, including roofing and siding may be completed. The final interior appointments and well-known press box components, including lights, sound systems, computers, chairs, wall finishing materials, and any other customer desired appointments can be added on site to produce the press box 14 desired by the customer. In this manner, it can be seen that the modular approach to building a press box 10 saves time, money and minimizes inconvenience for the customer.
[0064] The modular press box 14 also allows for additions to be easily made. After completing a full press box 14 , individual modules 16 , 22 can be added by simply removing the exterior appointments to expose the steel beam, column or tube. Then additional modules can be connected in the usual fashion and exterior appointments reattached to form a new and expanded press box 14 .
[0065] A general description of the present invention as well as a preferred embodiment of the present invention has been set forth above. Those skilled in the art to which the present invention pertains will recognize and be able to practice additional variations in the methods and systems described which fall within the teachings of this invention. Accordingly, all such modifications and additions are deemed to be within the scope of the invention which is to be limited only by the claims appended hereto. | A press box generally made from a plurality of modules assembled together wherein each module includes a plurality of tubes or beams and columns arranged to form a box-like frame structure. The modules can be connected to one another in a vertical or horizontal arrangement. Roof modules may be secured to the uppermost module and all modules are secured together. Nuts and bolts, welding, or other means can be used to secure connector plates on the box-like frames to corresponding connector plates or to secured adjacent tubes of different press box modules. The box-like modules can include a doorway, electrical wiring, windows, tables, counters, lights, flooring, ceilings, and be accessible by staircase. Balconies may be secured to one side of the modules as desired. The modules may be individually assembled in a first location, transported to a second location and secured to one another to form a press box. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/646,919, filed Jan. 25, 2005. The disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a control and interconnection assembly for providing an actuator with power supply and position sensors.
BACKGROUND OF THE INVENTION
Many devices, such as a turbocharger, use an apparatus to control their functions. For example, pneumatic and electric actuators are used to provide positional control of mechanisms on the turbocharger to adjust and maintain the pressure within the intake manifold of an engine.
FIG. 1 shows a schematic of a system using a turbocharger and an actuator to control boost pressure within the intake manifold 8 of engine 9 . The system consists of the vehicle's electronic control unit (ECU) 1 , actuator controller 2 , actuator 3 , turbocharger 4 and turbocharger control mechanism 5 . The ECU is connected to the actuator controller by a wire harness 6 having multiple conductors and connectors. The actuator controller is also connected to the actuator by a wire harness 7 having multiple conductors and connectors.
The ECU 1 will provide an electrical signal to the actuator controller 2 that will indicate a desired position of actuator 3 . The actuator controller will provide the necessary electrical control to the actuator. The actuator will move the control mechanism 5 of turbocharger 4 , to the desired position that will achieve a desired pressure within the intake manifold 8 of engine 9 . Actuator 3 also has a means of sensing its position and will feedback this signal to the actuator controller 2 . A “closed loop” control scheme is used to maintain a desired actuator position by comparing the feedback value to a desired value and adjusting the control signal, to the actuator, to maintain the position and resulting boost pressure. Other signals, such as an intake manifold pressure-sensing signal may also be monitored, by ECU 1 or actuator controller 2 , and used in the “closed loop” scheme to control the intake manifold pressure. The actuator controller can also monitor the performance of the actuator and provide feedback to the ECU. For example, items such as internal actuator temperature, voltage, current, actuator resistance, response time, and number of occurrences of a fault can be monitored and communicated to another system such as the vehicle ECU. Monitoring of some items may be a legislated requirement.
The electric actuator may use a D.C. motor as a means of actuation. The motor may use brushes for commutating its rotating member or it may be a brushless type motor. The brushless motor uses a number of magnetic sensors and an electrical control circuit to commutate its rotor and control its rotation. Magnetic devices, such as Hall effect devices (HED), are commonly used. The HED sensors must be in proximity to the motor's rotor and stator to effectively sense the magnetic field and provide a signal to a control circuit. The brushless motor also has a number of coils, wound with magnet wire, which must be connected to the control circuit. This type of actuator requires a number of electrical connections in addition to the accurate placement of the sensors. Control and connection methods such as separate control circuits may be difficult to assemble, costly, and undesirable. In addition, the motor, HED sensors, and control circuit may not be in one location. For example, the motor and hall sensors may be located in the actuator housing and the control circuit may be in the cover of the housing. This could require a complex interconnection system needing a multiple wire cable that may have durability and reliability issues. The following paragraphs will describe a system that will provide the required control and minimize components and interconnections.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 shows a schematic of a system using a turbo charger and actuator to control boost pressure within the intake manifold of an engine;
FIG. 2 shows a perspective view of the controller and interconnect arrangement with the housing partially removed and the cover attached;
FIG. 3 shows another perspective view of the controller and interconnect arrangement with the housing partially removed and the cover attached;
FIG. 4 shows a perspective view of the control and interconnect arrangement having the housing and cover removed and the motor disconnected from the arrangement;
FIG. 5 shows another perspective view of the control and interconnect arrangement having the housing and cover removed and the motor disconnected from the arrangement;
FIG. 6 shows a close up perspective view of the control and interconnect arrangement just prior to the motor being connected;
FIG. 7 shows a side perspective view of the control and interconnect arrangement with the motor connected; and
FIG. 8 shows an alternate embodiment of the invention depicting a perspective view of the control and interconnect arrangement having the housing cover removed and the motor circuit disconnected from the arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring now to FIGS. 2-7 , various views of the present invention can be seen. The actuator or device 10 consists of a brushless D.C. motor, intermediate gear 11 , and output gear/shaft 12 that are installed in a housing 33 . Pinion gear 17 is pressed onto the motor shaft and engages intermediate gear 11 . Bearing 15 is pressed to motor shaft 16 and is located in a counter bore in the housing.
Lead frame 13 and controller 14 are installed in a cover 32 . The cover 32 and a housing 33 form two portions of a casting. The casting is a housing for an actuator such as a turbocharger. Controller 14 is an electronic circuit that will provide the necessary control for the device and communicate to an external system such as a vehicle ECU. Lead frame 13 consists of formed electrical conductors 19 , 19 ′, supported by a plastic form 20 , HED sensors 25 , integral connector 21 and wire bond pads 28 . Integral connector 21 may be manufactured as part of plastic form 20 or connected as a separate component, to easily change the connector type for different applications. HED sensors 25 are attached to formed electrical conductors 19 , 19 ′ by suitable means such as welding or soldering. Slotted receptacles 22 are designed and formed to receive terminals 29 , of the device 10 , and make the electrical connection to the motor. A typical slotted receptacle 22 shown in the figures. This type is referred to as an “M” slot receptacle. Electrical conductor 19 , 19 ′ and plastic form 20 are also shown. The integral connector 21 has terminals 23 that will provide the electrical connection to an external system such as a vehicle ECU. The electrical conductors 19 , 19 ′ terminals 23 , and bond pads 28 may be formed as a portion of electrical conductors 19 , 19 ′ or they may be made separately and connected by suitable means such as welding. The lead frame is secured to the cover by suitable means such as fasteners.
Controller 14 is fastened to the cover by suitable means such as thermal adhesive or screws. The cover is made of a material such as aluminum that has suitable mechanical strength and thermal characteristics for transference between the controller and cover. Other devices such as transistors, field effect transistors, and voltage regulators, that are part of the controller circuit, may be fastened to the cover to achieve thermal requirements. Controller 14 is electrically connected to lead frame 13 by a suitable means such as wire bond 26 . Multiple wire bonds may be used depending upon the number of interconnections that are required. An alternate method for making the electrical connection between the lead frame 13 and controller 14 is the use of blade terminals and slotted receptacles similar to those described for making the motor-to-lead frame connection. Another method for making the connections is soldering.
During the assembly of the cover to the housing, locating features such as plastic guides 24 which project from the surface of the lead frame 13 can be aligned with recessed portions 27 on the device 10 . Aligning the plastic guides 24 with the recessed portions 27 will align the motor terminals 29 with slotted receptacles 22 and HED sensors 25 with recesses 30 on the surface of the device 10 . Connecting the terminals 29 with the slotted receptacles will make the electrical connection to the lead frame 13 . Additionally sliding the HED sensors 25 into the recesses 30 will position the sensors 25 adjacent the motor rotor 35 so that the position of the device 10 can be sensed by the sensors 25 . The sensors 25 sense the position of the permanent magnet or magnetic material in the motor rotor 35 . The inclusion of the HED sensors on the lead frame has eliminated the need for a separate motor sensor circuit and interconnects. The HED sensors 25 can also be supported on the plastic guides 24 . It is also possible for the HED sensors 25 to be a different type of sensor such as an induction sensor.
An alternate method for mounting the HED sensors is shown in FIG. 8 . The HED sensors are mounted on a separate circuit 34 . The circuit may be mounted separately or it may be mounted to the lead frame 13 . Connections between the lead frame 20 and circuit 34 , or between the control circuit and circuit 34 , are made by a suitable means such as wire bonding or soldering 36 and bond pads 28 . The soldering 36 and bond pads 28 connect the one or more electrical conductors 19 , 19 ′ of plastic form 20 with the electrical conductors 50 of the separate circuit 34 . The slotted receptacle 22 can be formed or attached to the electrical conductors or they could also be separate components and mounted and connected to the separate circuit 34 . The circuit is made from a material such as laminated fiberglass and epoxy. Mounting separate circuit 34 in the lead frame will eliminate the need of a multiple conductor cable or other method of connecting between the lead frame and circuit 34 .
The device 10 , or motor, may have 3 coils connected in a “Y” configuration. Three terminals, one from each coil, are connected together. The three terminals used for the “Y” connection do not require further connection to other components. The connection can be accomplished by interconnecting the three slotted receptacles in the lead frame. An alternative is to interconnect them on the D.C. motor. The later method will eliminate the need for 3 slotted receptacles in the lead frame.
The control system will operate in the following manner. The vehicles control system will provide an electrical signal to terminals 23 of integral connector 21 . The signal is communicated to device controller 14 via electrical conductors 19 , 19 ′ in lead frame 20 and wire bonds 26 connected to bond pads 28 . The device controller will deliver an electrical control signal, in similar manner, to the device 10 , through the electrical connection of slotted receptacles 22 and terminals 29 . The controller 14 can monitor device characteristics such as position, temperature, voltage, current, motor resistance, response time and the number of occurrences of overheating, or high voltage. The device will develop a torque that is transmitted to shaft 16 , pinion gear 17 , intermediate gear 11 and output gear/shaft 12 . The shaft of device 10 will rotate to the desired position for controlling the turbocharger. The sense signal from the HED sensors 25 will be communicated to the controller 14 , via electrical conductors 19 , 19 ′, in lead frame 20 , to provide feedback for communicating and controlling the device.
The HED sensors 25 can also be used to provide position control for the device. An alternate method of position control is to use a different type of sensor for example an inductive type sensor would be a suitable alternative. In this alternate embodiment the sensor would be located on one of the rotating parts, such as the output gear/shaft 12 . Other sensor components, such as the transmitter coil, receiving coil, and circuit could be located on the controller 14 or lead frame 13 .
The drawings shown have identified the cover 32 and housing 33 it is within the scope of this invention for the control and interconnection system for use in a control apparatus to be applied to either cover or housing.
The present interconnection arrangement allows for a method of assembly of a lead frame to a device using a quick connect type of arrangement using blade type terminals and slotted receptacles (in the lead frame). It is within the scope of this invention for the interconnect arrangement to interchange the location of the blade type terminals and the slotted receptacles within the interconnect arrangement. For example, slotted receptacles can be used on the device that will receive a blade type terminal used on the lead frame. The plastic guides and recesses formed on the surface of the device ease the alignment of the device to the lead frame so that when the guides and recesses are aligned the electrical terminals and electrical conductors as well as the sensors and device will be aligned for connection.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | Many devices, such as a turbocharger, use an apparatus to control their functions. For example, pneumatic and electric actuators are used to provide positional control of a mechanism on the turbocharger. The actuator must connect to the vehicles electrical system to provide suitable communication and control of the actuator. They must also have internal control and interconnection of devices such as sensors, electronic control unit, external electrical connector, and internal electrical connections. The electrical connections, placement of sensor, and placement of the controller are critical to the performance, reliability, and cost of the actuator. The control and interconnection system will provide the aforementioned requirements including a “quick connect” capability for electrical connections and ease of assembly. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to automated image processing and sorting, and specifically to automatic location of barcodes on material being sorted.
BACKGROUND OF THE INVENTION
[0002] Postal services and package delivery companies typically handle as many as several million parcels each being used increasingly in order to improve the efficiency and accuracy with which this huge volume of parcels is handled.
[0003] The process of sorting and tracking parcels as they proceed through sorting centers requires that each parcel bear two types of information: the destination address of the parcel and a tracking number, which uniquely distnguishes it from other parcels in the system. The information is generally printed on a parcel label, with the destination address in alphanumeric form. The tracking number, and frequently the address, as well, are printed in a machine-readable form, typically as a barcode. While the destination address tells where the parcel is to go, the tracking number assists the postal service or parcel company in managing its shipment operations and enables it to track parcels as they move through the system.
[0004] In order to sort and route the parcels automatically, the destination address and tracking number are typically read by a high-resolution imaging system. An image processor must then rapidly locate and read the barcode and the destination address on the parcel. This task is complicated by the fact that parcels vary greatly in size and shape, and may be placed on a conveyor belt for sorting in substantially any orientation. Furthermore, it frequently occurs that barcodes are located close to text and other graphic elements, as well as to tape or other shiny plastic items on the parcel, all of which add substantial “noise” to the barcode search. There is therefore a need for robust, high-speed methods that are capable of finding barcodes in a very large, noisy image within the tight time constraints of a large-volume package sorting system.
[0005] An exemplary method for locating barcodes, particularly two-dimensional barcodes, is described by Wang in U.S. Pat. No. 5,304,787, which is incorporated herein by reference. A stored image is processed to identify traversal of barcode start and stop patterns and to correlate these patterns with a common barcode image. The correlated patterns are used to identify a nominally rectangular area bouding the barcode in the image. The corners of the bounding area are used to identify the barcode for subsequent decoding.
SUMMARY OF THE INVENTION
[0006] Preferred embodiments of the present invention provide improved methods and systems for rapidly locating barcodes and other striped structures in a large and/or noisy image. For this purpose, the image (or a region of interest within the image) is divided up into tiles. Each tile is scanned along one or more parallel lines in order to detect patterns of parallel stripes that could be indicative of the presence of a barcode in the tile. Preferably, each tile is also scanned at a diagonal to the original scan direction, in order to detect patterns of stripes that are parallel or perpendicular to the original scan direction and might otherwise be missed. Tiles that are found to contain a sufficient number of mutually-parallel stripes are tagged as likely locations for a barcode. The angle of the stripes in these tiles provides an estimate of the orientation of the barcode.
[0007] Using this method, the entire image can be scanned quickly to identify all of the candidate barcode locations, without the need for an exhaustive search over all pixels and all possible stripe angles. The identification is largely insensitive to the barcode orientation angles and to the presence of noise and clutter in the vicinity of the barcodes. Based on these candidate locations and the associated orientation estimates, a precise orientation angle is determined for each barcode in the image. This angle is used to construct an exact retangle that bounds the outline of the barcode. The barcode can then be read reliable, as well as serving as a “landmark” for finding other image features of importance.
[0008] Embodiments of the present invention are particularly advantageous in the context of automated mail processing. A parcel sorting system that uses automatic barcode identification for recognizing and processing parcel labels is described, for example, in U.S. patent application 09/567,700, which is assigned to the assignee of the present patent application and is incorporated herein by reference. The principles of the present invention will also be found useful, however, in other applications in which barcodes or other striped structures must be identified in digital images, and particularly in large, noisy images.
[0009] There is therefore provided, in accordance with a preferred embodiment of the present invention, a method for locating a barcode in an image, including:
[0010] dividing the image into a plurality of tiles;
[0011] scanning each of the tiles so as to detect a pattern of stripes associated with the barcode in at least one of the tiles;
[0012] analyzing the pattern of stripes so as to determine an angle of orientation of the barcode; and
[0013] responsive to the determined angle, defining bounds of the barcode that are aligned with the pattern of the stripes.
[0014] Preferably, scanning each of the tiles includes scanning so as to detect the pattern of stripes substantially irrespective the angle of orientation of the barcode. Most preferably, scanning each of the tiles includes scanning on a first line through the tile in a first scan direction so as to detect the stripes in the tile that are crossed by the first line, and scanning on a second line through the tile in a second scan direction, at a diagonal to the first direction, so as to detect the stripes in the tile that are crossed by the second line.
[0015] Preferably, scanning each of the tiles includes detecting the pattern of stripes in a first one of the tiles, and defining the bounds of the barcode includes seeking the bounds of the barcode in at least a second one of the tiles, adjacent to the first one of the tiles.
[0016] Additionally or alternatively, the stripes have respective ends, and defining the bounds of the barcode includes locating the ends of the stripes and delimiting a rectangle containing the barcode and having sides defined by the ends of the stripes. Preferably, defining the bounds of the barcode includes finding extreme lines of the barcode corresponding to first and last ones of the stripes of the barcode, and locating the ends of the stripes includes scanning along at least some of the stripes intermediate the first and last stripes in a direction parallel to the extreme lines.
[0017] Preferably, the method includes reading the barcode responsive to the bounds.
[0018] There is also provided, in accordance with a preferred embodiment of the present invention, a method for finding a pattern of parallel stripes in an image, which includes a pluarality of pixels having respective pixel values, the method including:
[0019] scanning an area of the image along a selected scan line in a first scan direction so as to locate a first sequence of the pixels on the line having pixel values within a predetermined range;
[0020] starting from each of at least some of the pixels in the sequence, scanning in a second scan direction, transverse to the first scan direction, to both sides of the line, so as to reach endpoint pixels defined by the first of the pixels on both sides of the line having pixel values outside the predetermined range;
[0021] joining the endpoint pixels on each side of the line to define respective edges of a first one of the stripes;
[0022] repeating the steps of scanning the area in the first and second scan directions and of joining the endpoint pixels for at least a second sequence of the pixels on the line having pixel values within the predetermined range, so as to define the respective edges of at least a second one of the stripes; and
[0023] comparing the edges of at least the first and second striped to find the stripe pattern in the image.
[0024] Preferably, the method includes scanning the area along a further scan line, in a direction diagonal to the first scan direction, so as to locate third and fourth sequences of the pixels on the further scan line having pixel values within the predetermined range, and repeating the steps of scanning in the second direction, joining the endpoint pixels and comparing the edges with respect to the third and fourth sequences of the pixels and the diagonal direction.
[0025] Further preferably, comparing the edges includes determining an orientation of the stripes in the pattern. Most preferably, comparing the edges includes identifying the stripes as belonging to the stripe pattern only if the edges are mutually parallel to within a predetermined limit.
[0026] In a preferred embodiment, the pattern includes a barcode.
[0027] There is additionally provided, in accordance with a preferred embodiment of the present invention, apparatus for locating a barcode in an image, including an image processor, which is arranged to divide the image into a plurality of tiles, to scan each of the tiles so as to detect a pattern of stripes associated with the barcode in at least one of the tiles, to analyze the pattern of striped so as to determine an angles of orientation of the barcode, and responsive to the determined angle, to define bounds of the barcode that are aligned with the pattern of the stripes.
[0028] In a preferred embodiment, the apparatus includes an image capture device, which is arranged to capture the image of an object on which the barcode appears. Preferably, the image processor is arranged to read the barcode responsive to the bounds so as to extract information contained in the barcode, and the apparatus includes a sorter, which is arranged to sort the object responsive to the information.
[0029] There is further provided, in accordance with a preferred embodiment of the present invention, apparatus for finding a pattern of parallel stripes in an image, which includes a plurality of pixels having respective pixels values, the apparatus including an image processor, which is arranged to scan an area of the image along a selected scan line in a first scan direction so as to locate a first sequence of the pixels on the line having pixel values within a predetermined range, and starting from each of at least some of the pixels in the sequence, to scan in a second scan direction, transverse to the first scan direction, to both sides of the line, so as to reach endpoint pixels defined by the first of the pixels on both sides of the line having pixel values outside the predetermined range, to join the endpoint pixels on each side of the line to define respective edges of a first one of the stripes, and to repeat the steps of scanning the area in the first and second scan directions and of joining the endpoint pixels for at least a second sequence of the pixels on the line having pixel values within the predetermined range, so as to define the respective edges of at least a second one of the stripes, and to compare the edges of at least the first and second stripes to find the stripe pattern in the image.
[0030] There is moreover provided, in accordance with a preferred embodiment of the present invention, a computer software product for locating a barcode in an image, including a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to divide the image into a plurality of tiles, to scan each of the tiles so as to detect a pattern of stripes associated with the barcode in at least one of the tiles, to analyze the pattern of stripes so as to determine an angle of orientation of the barcode, and responsive to the determined angle, to define bounds of the barcode that are aligned with the pattern of the stripes.
[0031] There is furthermore provided, in accordance with a preferred embodiment of the present invention, a computer software product for finding a pattern of parallel stripes in an image, which includes a plurality of pixels having respective pixel values, the product including a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to scan an area of the image along a selected scan line in a first scan direction so as to locate a first sequence of the pixels on the line having pixel values within a predetermined range, and starting from each of at least some of the pixels in the sequence, to scan in a second scan direction, transverse to the first scan direction, to both sides of the line, so as to reach endpoint pixels defined by the first of the pixels on both sides of the line having pixel values outside the predetermined range, to join the endpoint pixels on each side of the line to define respective edges of a first one of the stripes, and to repeat the steps of scanning the area in the first and second scan directions and of joining the endpoint pixels for at least a second sequence of the pixels on the line having pixel vales within the predetermined range, so as to define the respective edges of at least a second one of the stripes, and to compare the edges of at least the first and second stripes to find the stripe pattern in the image.
[0032] The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] [0033]FIG. 1 is a schematic, partly pictorial illustration of a system for sorting parcels, in accordance with a preferred embodiment of the present invention;
[0034] [0034]FIG. 2 is a schematic representation of an image capture and divided into tiles for processing in the system of FIG. 1, in accordance with a preferred embodiment of the present invention;
[0035] [0035]FIG. 3 is a flow chart that schematically illustrates a method for locating a barcode in an image, in accordance with a preferred embodiment of the present invention;
[0036] [0036]FIGS. 4A and 4B are schematic representations of a tile within an image of a parcel, showing details of a barcode in the tile, which is processed in accordance with a preferred embodiment of the present invention;
[0037] [0037]FIG. 5 is a flow chart that schematically illustrates a method for detecting parts of a barcode in an image, in accordance with a preferred embodiment of the present invention;
[0038] [0038]FIGS. 6A and 6B are schematic representations of a portion of an image of a parcel, illustrating construction of a rectangle bouding a barcode in the image, in accordance with a preferred embodiment of the present invention; and
[0039] [0039]FIG. 7 is a flow chart that schematically illustrates a method for constructing a rectangle that bounds a barcode in an image, in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] [0040]FIG. 1 is a schematic, pictorial illustration of a system 20 for parcel sorting, in accordance with a preferred embodiment of the present invention. A parcel 22 is transported by a conveyor 24 . The parcel has a label 26 , which typically contains a barcode 28 . An image of the parcel, preferably a gray-scal image, is captured by an imaging device 30 , preferably a line scan camerca operting in a “push-broom” mode. The image captured by the camera is digitized and passed to a processor 32 , which applies the methods described hereinbelow to locate barcode 28 on the parcel. Alternatively, the processor may receive the image from some other source, or it may retrieve the image from a memory (not shown). Typically, after locating the barcode, the processor reads the barcode and address on label 26 automatically and drives a sorter 34 to route the parcel accordingly.
[0041] Processor 32 preferably comprises a general-purpose computer, programmed with appropiate software to carry out the methods of the present invention. This software may be downloaded to the processor in electronic form, over a network, for example, or alternatively, it may be supplied on tangible media, such as CD-ROM, for installation in the processor. Such software may similarly be adapted for use in other image processing applications, and may thus be supplied to and installed on other computers in like manner. Alternatively, the methods described herein may be implemented using dedicated hardware or a programmable digital signal processor, or using a combination of dedicated and/or programmable elements and/or software. The use of processor 32 in the context of parcel sorting system 20 is described here by way of example, and not limitation.
[0042] [0042]FIG. 2 is a schematic representation of an image of parcel 22 captured by imaging device 30 and processed by processor 32 , in accordance with a preferred embodiment of the present invention. This image contains two barcodes 28 , as is typical on many of the parcels encountered by parcel sorting systems. In order to process the image, processor 32 identifies a region of interest (ROI) 36 , corresponding roughly to the area of parcel 22 , as distinguished from conveyor 24 on which the parcel is resting. The ROI is divided up into tiles 38 for further processing, wherein each of the tiles is preferably about 150 x 150 pixels in size.
[0043] [0043]FIG. 3 is a flow chart that schematically illustrates a method for processing images such as that shown in FIG. 2 so as to find barcodes 28 in the image, in accordance with a preferred embodiment of the present invention. As noted above, processor 32 preferably finds ROI 36 , at an ROI definition step 40 . Alternatively, the method of FIG. 3 may be applied to the entire image and not limited to a certain ROI. The ROI is divided into tiles of appropriate size, at a tiling step 42 . The processor checks each of the tiles rapidly, at a tile selection step 44 , to determine which of the tiles are likely to contain all or part of a barcode. Step 44 is based on locating parallel lines, or stripes, in the tile. This step is described in greater detail hereinbelow with reference to FIGS. 4A, 4B and 5 . Preferably, a tile is considered to contain a barcode (or part of one) if at least five such stripes are found in the tile, and most of the stripes are mutually parallel to with about 1°.
[0044] The orientation of the stripes that are found in a candidate tile provides an initial estimate of the orientation of the actual barcode. Processor 32 uses this estimate as a basis for determining the precise orientation angle of the barcode, at an angle calculation step 46 . For the purpose of this step, the tile area is preferably binarized. Following binarization, the black pixels in the tile, which presumably belong to the barcode, are sampled, and lines are fitted through the sampled points at angles that are close to the estimated barcode orientation angle. The precise orientation angles of the stripes are then calculated using methods known in the art, such as Hough transforms.
[0045] In order to accurately decode and use all of the information provided by barcode 28 , it is important to define the bounds of the barcode precisely. For this purpose, processor 32 outlines a rectangular box containing the barcode, at a box definition step 48 . This step is described in detail hereinbelow with reference to FIGS. 6A, 6B and 7 . If necessary, when the barcode extends from one tile into the next, the parts of the barcode in the neighboring tiles are found, and the box is extended accordingly. In this case, the processor preferably eliminates the neighboring tile or tiles from any further search, at a removal step 49 , since the barcode in these tiles has already been found.
[0046] After defining the bounding box of the barcode, the processor reads the barcode contents, at a reading step 50 . Additionally or alternatively, the barcode location and geometry are used in identifying and analyzing other features in the image of parcel 22 , and particularly of label 26 , as described, for example, in the above-mentioned U.S. Patent Application 09/567,700.
[0047] Reference is now made to FIGS. 4A, 4B and 5 in order to describe details of tile selection step 44 , in accordance with a preferred embodiment of the present invention. FIGS. 4A and 4B are schematic representations of an image of one of tiles 38 , in which a part of barcode 28 is located. FIG. 5 is a flow chart that illustrates a method for rapidly scanning tile 38 to determine whether it contains parallel stripes that would qualify it as a candidate to contain the barcode.
[0048] In FIG. 4A, three parallel vertical scan lines 56 are defined, covering a test area 54 within tile 38 . Alternatively, a greater or lesser number of the scan lines may be defined, and test area 54 may also be expanded to cover all of tile 38 . Further alternatively or additionally, horizontal scan lines may be used for this purpose. At a vertical scanning step 70 (FIG. 5), processor 32 scans down a first one of scan lines 56 until it reaches the bottom of the test area, at a vertical scan completion step 71 . When the processor encounters a black pixel, at a black pixel step 72 , it then scans transversely, to the left and right, at a transverse scanning step 73 . The transverse scan is terminated when a white pixel is encountered on each side of the scan line. Typical transverse scan lines 58 generated at step 73 are shown in FIG. 4A.
[0049] The ends of each line 58 are marked as endpoints 60 . It will be observed that for each black stripe of the barcode that is traversed by vertical scan line 56 , the two sets of endpoints at either side of line 56 define two line segments that run along the opposing parallel edges of the stripe. In FIG. 4A, only the endpoints of the transverse scan lines are marked, while for simplicity of illustration, the area between the endpoints is left blank (except in one of the scanned areas in which lines 58 are drawn). Thus, processor 32 locates stripes of the barcode by finding two opposing sets of endpoints 60 that define line segments that are parallel to within a predetermined limit, typically 1-2°. The orientation of the stripe is given approximately by the slopes of the line segments. As noted above, if a sufficient number of these stripes are found in a given tile, and the stripe are mutually correlated in their orientation angles, the processor determines that it has found a barcode.
[0050] After scanning the first of vertical scan lines 56 in this manner, processor 32 preferably repeats the scan procedure along additional scan lines in order to ensure that it has not missed a barcode in the tile. First, the processor goes on to scan the other vertical scan lines 56 in substantially the same manner as it scanned the first line, at a vertical scan repetition step 76 . Most preferably, the processor also performs at least one scan along a diagonal scan line 62 (FIG. 4B), at a diagonal scanning step 78 . As in the vertical scan, stripes of bar code 28 are found by scanning on diagonal transverse scan lines 64 , in order to find diagonal endpoints 66 . The diagonal scan is important in cases in which the stripes of the barcode are parallel to or perpendicular to vertical scan lines 56 . If not for the diagonal scan, the processor might fail to identify the barcode in such a case.
[0051] Reference is now made to FIGS. 6A, 6B and 7 in order to describe details of box definition step 48 , in accordance with a preferred embodiment of the present invention. FIGS. 6A and 6B are schematic representatives of an area of the image of parcel 22 containing barcode 28 . This area has been expanded, relative to the area of tile 38 shown in FIGS. 4A and 4B, by adding the neighboring tiles so as to take in all of the barcode in question. FIG. 7 is a flow chart that schematically illustrates a method for determining the outline of a box 90 (FIG. 6B) that completely contains the barcode.
[0052] Using the barcode angle for tile 38 that was found at step 46 (FIG. 3), processor 32 defines a parallelogram 80 (FIG. 6A) in which barcode 28 can be located, at a parallelogram definition step 92 (FIG. 7). The parallelogram is preferably centered in the tile in which the barcode was identified, but it is expanded to include parts of the neighboring tiles. Sides 82 of the parallelogram are chosen to run at the determined axial angle of barcode 28 (i.e., perpendicular to the angle of the stripes), preferably near the edges of the barcode. As shown in FIG. 6A, sides 82 may still not be exactly aligned with the actual edges of the barcode, typically because of skew in the image that was originally captured by imaging device 30 .
[0053] The image within parallelogram 80 is processed to find the precise bounds of the barcode. Preferably, the image is first binarized, at a binarization step 94 . Lines 84 at the transverse angle of barcode 28 (perpendicular to sides 82 ) are fitted to the stripes of barcode 28 that fall within parallelogram 80 , at a fitting step 96 . The last line at either end of the barcode is identified as an extreme line 86 (FIG. 6B) of the barcode, at an extremity finding step 98 . The extreme lines are easily identified, since beyond these lines there is a wide extent of white space before any further black features are encountered.
[0054] A subset of lines 84 , preferably the lines that are fitted to the stripes near the center of barcode 28 , are scanned transversely (in a direction parallel to extreme lines 86 ) to find the ends of these central lines, in a transverse scanning step 100 . In this case, too, it is easy to find the ends of the lines, simply by noting the points at which white areas of the image are encountered at either end of each line. The ends of these central lines define the exact loci of edges 88 of the barcode. These edges are used to define a complete box 90 containing the barcode, at a box completion step 102 . The box is preferably extended slightly beyond extreme lines 86 in order to ensure that the information in the first and last stripes of the barcode is not lost when the barcode is read at step 50 (FIG. 3). It will be observed that box 90 contains only the barcode of interest, while excluding other nearby barcode fragments and text.
[0055] Although preferred embodiments are described hereinabove with reference certain specific methods for line fitting and angle determination, those skilled in the art will appreciate that other methods of image processing may also be used for these purposes. While the inventor has found that image binarization is useful in rapid processing of image data in certain of the processing phases described above, gray-scale and color image processing methods may also be used in alternative embodiments of the present invention. Moreover, although preferred embodiments of the present invention are directed to finding and processing barcodes on parcels and other objects, the principles of the present invention may similarly be applied to detecting and processing other patterns of parallel lines and stripes that may be encountered in automated image analysis, including patterns appearing in binary, gray-scale and color images. The term “barcode” as used in the context of the present patent application and in the claims should therefore be taken to refer to substantially any machine-readable code that comprises a pattern of contrasting stripes.
[0056] It will thus be appreciated that the preferred embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. | A method for locating a barcode in an image includes dividing the image into a plurality of tiles, and scanning each of the tiles so as to detect a pattern of stripes associated with the barcode in at least one of the tiles. The pattern of stripes is analyzed so as to determine an angle of orientation of the barcode. Responsive to the determined angle, bounds of the barcode are defined in alignment with the pattern of the stripes. | 8 |
This application claims the benefit of U.S. Provisional Application Ser. No. 61/684,316, filed Aug. 17, 2012 which is incorporated herein as if fully rewritten.
FIELD
Described herein is a method, apparatus and kit for the treatment of neurodegenerative diseases and impairments with the use of odorants.
BACKGROUND
Alzheimer's disease and dementia are diseases which result in a progressive deterioration of neurons in the brain which causes cognitive deterioration and changes in behavior. With Alzheimer's disease, there is loss of short-term memory and minor forgetfulness which becomes greater as the illness progresses to major memory loss with a relative preservation of older memories. As the disease progresses even further, there is cognitive or intellectual impairment which extends to language degeneration (having difficulty remembering words to being completely unable to speak, read, or write), loss of the ability to execute or carry out learned purposeful movements, and a loss of ability to recognize objects, persons, sounds, shapes, or smells.
Neurons are cells which transmit information via synapses. Neurons connect to each other to form neural networks. Neurons are electrically excitable cells which transmit information by electrical and chemical signaling by synapses which establish connections with other neuron cells. With the progression of Alzheimer's disease and other neurodegenerative diseases, the connectivity of the neurons are adversely affected, such as by the generation of plaque and abnormal proteins called tau proteins.
SUMMARY
The olfactory system beginning in the nose and ending in the cortex and central structures of the brain is the only part of the adult mammalian brain capable of stimulation and regeneration. A method, apparatus and kit have been discovered which regenerate the connections of the neurons of the brain and central nervous systems such that connectivity of the neurons is improved to effect improvement in memory loss, language degeneration, loss of the ability to execute or carry out learned purposeful movements, and a loss of ability to recognize objects, persons, sounds, shapes, or smells. The method includes the delivery of a blend of olfactory enrichment odorants to and through the nose with the delivery of the odorants being under a positive pressure to affect air flow with the odorant at a room temperature (25 degrees C.) delivery rate of air containing odorant of from about 0.5 to about 2 liters per minute. Stimulation of the olfactory neurons in the nose by the odorant blend stimulate neurogeneis (new brain development) in the olfactory brain regions affected neuro-impairments caused by disease or trauma including a cognitive impairment which is a prodromal state in the development of dementia, traumatic brain injury affecting the olfactory regions of the brain, including the frontal lobe, post stroke brain damage involving the frontal lobe regions and olfactory cortices of the brain, Parkinson's disease, schizophrenia and chronic depression. The stimulation of neurogeneis effects a reversal of brain impairments caused by the latter diseases and injuries. In a very important aspect, stimulation of the olfactory neurons in the nose by the odorant blend stimulate neurogeneis in the olfactory brain regions affected by Alzheimer's and other types of dementia and reverse neuropathologies of Alzheimer's disease and dementia, namely hyperphoshorylation of neurofibrillary tangles and tau proteins. The blend of odorants includes a blend of a plurality of odors including citrus (orange), lemon, rosemary, cinnamon, banana oil, cumin, vanillin, ethylvanillin, garlic, paprika, curry, nutmeg, thyme, tarragon, celery, ginger, lavender, marjoram, basil leaves, cardamom, cloves, chocolate and anise at a positive pressure to affect air flow with the odorant delivery rate of from about 0.5 to about 2 liters per minute. In an important aspect, at least three of the odors should be used. And in a very important aspect, the odorants include a blend of citrus (orange), lemon, rosemary and cinnamon at a positive pressure to affect air flow with the odorant delivery rate of from about 0.5 to about 2 liters per minute. The odorants are dispersed in a media which permits them to be swept into the nose for intranasal application of the odorants. In an important aspect, the media is a pharmaceutically acceptable oil, such as mineral oil.
The odorants are in a concentration for each odorant in the range of from about 1 to about 6 weight percent and are driven through the nose to contact olfactory tissue and olfactory receptor neurons. The method brings odorants in contact to this tissue in constant flow or pressure, which is needed to stimulate regeneration (or birth) of olfactory sensory system, which in turn, stimulates the olfactory bulb and olfactory cortices to be active by the intranasal administration of a blend of odorants dispersed in a media, the odorant blend including at least two, preferrably three, of the odorants citrus (orange), lemon, rosemary, cinnamon, banana oil, cumin, vanillin, ethylvanillin, garlic, paprika, curry, nutmeg, thyme, tarragon, celery, ginger, lavender, marjoram, basil leaves, cardamom, cloves, chocolate and anise by pumping the blend as part of a flow of gas which includes oxygen and odorant blend. The flow created by a pump creates a positive pressure to create a flow of oxygen and odorant blend through the nose. The concentration of the blend, the ratio of odorants, the rate of flow of the blend and oxygen, a time of treatment, and the ratios of odorants in the blend effective for effecting an improved neuro-function of a person afflicted with the neurodegenerative disease or trauma. In an important aspect for a subject afflicted with a neurrodgenerative disease such as Alzheimer's disease and/or dementia, the concentration of the odorant blend, the ratio of odorants, the rate of flow of the blend and oxygen, a time of treatment, and the ratios of odorants in the blend effective for effecting an improvement of at least 50%, preferably 100% and even more preferably 150% in short-term verbal memory of a person afflicted with the neurodegenerative disease, the improvement being measured by a California Verbal Learning Test, Adult, Version 2. The time of treatment is from about 12 hours daily for at least about two weeks, and preferably, for at least about one month. The method contemplates a treatment with a concentration of odorants at positive pressures for a time which effects new brain development (i.e. neuroplasticity) and reversal of pathological features of Alzheimer's disease or dementia in mammals.
The apparatus used to deliver the odorants includes a pump, an air filter, a flow meter, a check valve, an odorant chamber and a cannula configured to deliver the odorant to users afflicted with the neuro degeneration disease. The odorant chamber contains the blend of odorants which are pleasant, tolerable and effect enrichment to human memory after or during the deleterious effects of Alzheimer's disease and dementia and other neurodegenerative diseases. The pump generates a current of filtered air directed into the odorant chamber through a tube with flow-directed valves. This flow is channeled through a user-controlled flow meter, on the outside of the device, for regulation of the rate of flow of odorant containing air/oxygen to the nose. The cannula directing the flow to the nose comes in different shapes and sizes, depending on the shape of a user's nose. The inside of human nose is enriched as the odorants exit the cannula and contact olfactory tissue.
In another aspect, a kit is provided where the kit which includes an apparatus which is configured for the administration of a blend of odorants. The apparatus in the kit comprises a pump; a line which is effective for supplying air to a vessel configured to contain a blend of odorants; a line from the vessel to a cannula configured for lodgment into the nose, the pump being configured to provide a positive pressure and a flow of gas into the cannula and nose at a rate of from about 0.5 to about 2 liters per minute; and at least one additional vessel which includes a second vessel containing a blend of odorants; and wherein the odorant blend in the second vessel includes citrus, lemon, rosemary and cinnamon. The kit is configured for administering the blend including pumping the blend as a part of a flow of gas which includes oxygen and odorant blend. The flow created by the pump creates a positive pressure to create a flow of oxygen and odorant blend through the nose. The concentration of the blend, the ratio of odorants, the rate of flow of the blend and oxygen, a time of treatment, and the ratios of odorants in the blend are effective for effecting an improvement of at least 50%, preferably 100% and even more preferably 150% in short-term verbal memory of a person afflicted with the neurodegenerative disease, the improvement being measured by a California Verbal Learning Test, Adult, Version 2. The kit also may include instructions as to the time of administration of the blend, such as 12 hours daily for one month.
FIGURES
FIG. 1 is an illustration of the device used to practice the method described herein.
FIG. 2 illustrates a Nuclear Magnetic Resonance spectra of the odorant of lemon.
FIG. 3 illustrates a Nuclear Magnetic Resonance spectra of the odorant of sweet orange.
FIG. 4 illustrates a Nuclear Magnetic Resonance spectra of the odorant of rosemary.
FIG. 5 illustrates a Nuclear Magnetic Resonance spectra of the odorant of cinnamon.
DETAILED DESCRIPTION
The apparatus includes cannula 2 having a conduit 4 into an odorant chamber 6 containing a blend of odorants 8 . Pump 10 pumps air at a positive pressure through conduit 12 to filter 14 and flow meter 16 past check valve 18 into the odorant chamber 6 . The air under positive pressure sweeps the odorants from the blend of odorants into conduit 4 and pushes the odorants through cannula 2 into the nose of the user.
In the important aspect, the blend of odorants includes sweet orange also called citrus sinensis. Bergamont orange also called citrus bergamia also can be used in lieu of sweet orange or blended with sweet orange. The blend further includes lemon oil also called citrus limon. As used herein, “citrus,” as opposed to “citrus limon” means sweet orange or bergamont orange. The odorant blend also includes Cinnamon oil also known as cinnamomum zeylanicum and rosemary oil also called rosmarinus officinalis. Odorants which are not from a botanical source such as cinnamonum zeylanicum, but are flavorings which mimic the botanical sourced odorant also may be used. The individual odorants range in concentration of from about 0.5 weight percent to about 6.0 weight percent in the odorant chamber 6 and are delivered at an air/odorant rate of from about 0.5 to about 2 liters per minute. The odorant are diluted in mineral oil to obtain the latter concentration range. The device is powered by electricity through a 9V adapter plugged to any electrical source, such as a wall outlet.
In an important aspect, the apparatus is portable to permit treatment over a day/evening. In this aspect, the pump is operated with DC current being supplied by a rechargeable battery. The apparatus has a housing to accommodate the battery and an outlet to effect recharging.
Tests involving a blend of sweet orange, bergamont orange, citrus limon, cinnamon and rosemary were conducted on volunteers with each odorant dispersed in mineral oil at a concentration of 3 weight percent at an air/odorant flow rate of 0.5 liters/minute. The subjects were subjected to application of the odorant blend at the aforedescribed positive pressure for two weeks at 12 hours per day. Tests of memory functions are shown in the table below:
CVLT Recognition/Recall
Pre-OND
Post-OND
Total Recognition Raw Score
12
16
Recognition Z score
−2.5
0
Total False Positives
10
0
Total False Positives Z
3.5
−0.5
Short Delay Free Recall
5
15
Short Delay Free Recall Z
−3
1
Short Delay Cued Recall
6
16
Short Delay Cued Recall Z
−3
1
The result support increased recognition and markedly increased free by 200% and cued by 150% short-term memory recall in this volunteer following Olfactory Treatment Delivery System (OND treatment). Moreover, it was found that the treatment increased the sense of smell. Of two volunteers, one had a remarkable anosmia and was unable to identify the n-butanol odorant at the maximum concentration supplied in the olfact-combo olfactometer. After 4 weeks of OND, he identified up to the 6th dilution of the n-butanol (maximum is 9th dilution). Significant changes in the scores for odor identification, odor memory and odor discrimination were also observed for both volunteers. | A method, apparatus and kit have been discovered which regenerate with the use of odorants the connections of the neurons of the brain and central nervous system in the treatment of such person afflicted neuro-disorders caused by disease or trauma. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to communications methods.
BACKGROUND OF THE INVENTION
[0002] The modern age may best be characterized by the overwhelming amount of information transmitted between individuals for personal and business purposes alike. An increasing number of individuals and entities communicate increasingly frequently, exchange increasingly more data, by an increasing number of means.
[0003] It is typically important to both the business providing a service to a customer, and to the customer receiving a service from a business that a dependable and convenient communication link exist between them. Customers place a high value on receiving the products and services they have purchased from a business at the price and under the terms to which they have agreed, and businesses depend on satisfied customers to ensure their viability in a competitive market. To achieve these ends, communication between customers and businesses is paramount. Customers and business representatives must talk or correspond in writing to provide and receive information about products and services, provide and receive price quotes, negotiate and sign service agreements and resolve problems which may arise.
[0004] The typical contemporary business has kept pace with the technological advances in the field of communications which have increased and diversified the methods by which customers and businesses may communicate. This is demonstrated in FIG. 1 , reference to which is now made, which shows an exemplary contemporary business card 10 for Busy Business Inc., an exemplary contemporary business. As shown in FIG. 1 , the contact details 12 on business card 10 include a mailing address 14 for postal deliveries, a telephone number 16 for telephone calls, a fax number 18 for fax transmissions, an SMS number 20 for receiving text messages, an email address 22 for email transmissions, and a website address 24 for Internet access.
[0005] Both businesses and customers can benefit from the convenience afforded by the quantity and variety of communications options. For example, a customer having a busy day may find that he has missed the opportunity to call his service provider during regular business hours, but the options of contacting the business outside of office hours by fax or email remain available to him.
[0006] Ironically, as evidenced by the quantity of details shown on business card 10 , it is the very increase and diversification of communication options which has itself created a communications impediment. The contemporary individual is typically overwhelmed with contact details, the majority of which he cannot hope to remember. He must be equipped at the very least with an address book, or preferably, with an electronic organizer. Keeping up with ever-increasing contact details, due to the advances of communications technology, and ever-changing contact details, due to physical relocations, area-code changes, communications service provider switches, etc. has graduated from a minor inconvenience to a more bothersome aggravation. The contemporary experience of writing a quick business email in the middle of the night which will be at its destination at the start of the next business day is a welcome one and a modern convenience. However, both unwelcome and inconvenient to a similar degree, is the “b as in boy”, “d as in dog” recitation required to provide an email address over the phone accurately.
[0007] Businesses in particular cannot afford to lose touch with their customers, and historically, in recognizing that it has been in their best interest to make it easier for customers to reach them, businesses have invested considerable efforts in minimizing the cost in both time and money for customers to reach them. These efforts have included business reply mail, which saves customers the cost of a stamp when communicating with the business and toll free numbers, which save customers the cost of a telephone call when calling the business. Businesses have also used toll free numbers with the name of the business spelling out the phone number using the alphanumeric keypad to help customers easily retain and retrieve their contact information. Telephone numbers have been set to jingles and seared into our memories by constant repetition on the public airwaves. However, in the modern context, these solutions are only partial due to the increased number of the means of communication and contact details.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
[0009] FIG. 1 is an exemplary representation of a contemporary business card;
[0010] FIG. 2 is an exemplary representation of the business card shown in FIG. 1 , the contact details provided on which have been compacted in accordance with a preferred embodiment of the present invention; and
[0011] FIG. 3 is an illustration of an innovative contact details management system constructed and operative in accordance with a preferred embodiment of the present invention.
[0012] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
SUMMARY OF THE INVENTION
[0013] There is provided, in accordance with a preferred embodiment of the present invention, a method including associating a communication nickname with a business for use with all existing types of customer communication.
[0014] Additionally, in accordance with a preferred embodiment of the present invention, the method may include routing each communication for the business transmitted using the communication nickname in accordance with a communication access number associated with the type of the communication.
[0015] Further, in accordance with a preferred embodiment of the present invention, the method may include having a compact contact detail for each type of customer communication which includes the communication nickname as a major portion thereof.
[0016] Still further, in accordance with a preferred embodiment of the present invention, the types of communication may include mail, fax, telephony, mobile telephony, short message service (SMS), internet and email.
[0017] There is also provided, in accordance with a preferred embodiment of the present invention, a method including providing a business with a unified communications number for all types of customer communication and mapping the unified communications number to each address for the business issued by the communication service providers of the business.
[0018] Additionally, in accordance with a preferred embodiment of the present invention, the method may include routing communications addressed to the unified communications number to the appropriate the address as a function of the type of communication.
[0019] Moreover, in accordance with a preferred embodiment of the present invention, the unified communications number may be unique to the business.
[0020] Further, in accordance with a preferred embodiment of the present invention, the types of communication may include mail, fax, telephony, mobile telephony, short message service (SMS), internet and email.
[0021] Finally, in accordance with a preferred embodiment of the present invention, the providing may include selecting a temporary unified communications number, confirming with each the communication service provider that the temporary unified communications number is not being used by any other business and, if so, mapping the unified communications number between the business and the communication access numbers assigned to the business by the communication service providers.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0023] Applicant has realized that the inconvenience caused by an overabundance of contact details may be overcome by taking advantage of the means by which modern communications may be routed from one communications access number to another through central routing equipment and forwarding services.
[0024] FIG. 2 , reference to which is now made, depicts a business card 30 , which includes compact contact details 32 which may, in accordance with a preferred embodiment of the present invention, replace the full-length contact details 12 provided on prior art business card 10 , while not detracting from the full range of communication versatility provided by full-length contact details 12 . Compact contact details 32 may all contain as their single or chief component a “communications nickname” uniquely associated with one business. For example, the communications nickname for Busy Business Inc. may be “*2879”.
[0025] As shown in FIG. 2 , in accordance with a preferred embodiment of the present invention, one simple, short and generally easily remembered number such as “*2879” may be substituted for nearly all of the disparate and lengthy contact details of a business. In the example shown in FIG. 2 , the single contact detail “*2879” replaces the mailing address, phone number, fax number, text message number and website address of Busy Business, Inc. In accordance with a preferred embodiment of the present invention, some contact details, such as email address 36 shown in FIG. 2 , may have a prefix or suffix appended to the communications nickname. In the case of compact contact details having prefixes or suffixes appended to the communications nickname, it will be appreciated that the communications nickname remains a unifying element between all of the compact contact details for a single business.
[0026] Compact contact details 32 for a business may comprise fewer communication access numbers (CANs) 34 than full-length contact details 12 . For example, it is shown in a comparison between FIGS. 1 and 2 that there may be a reduction from six CANs (indicated by reference numerals 12 , 14 , 16 , 18 , 20 , 22 and 24 ) in full-length contact details 12 to two CANs in compact contact details 32 .
[0027] Reference is now made to FIG. 3 , which illustrates a compact contact details coordination unit (CCDCU) 40 , operative in accordance with a preferred embodiment of the present invention, in conjunction with currently available types of communications service providers (CSPs) 42 . CCDCU 40 may be employed to coordinate assignments of unique communications nicknames 60 to businesses 44 . CCDCU 40 may compose a database 46 in which an association between each business 44 and its assigned communications nickname 60 may be recorded.
[0028] Each communication service provider 42 may provide one type of communication service to businesses 44 and may, in accordance with a preferred embodiment of the present invention, maintain and operate a database 52 and a router 54 for routing each unique communications nickname to its proper address. As shown in FIG. 3 , exemplary CSPs 42 providing communications services to business 44 may include a post office 42 a , one or more telephone service providers 42 b , one or more cellular phone service providers 42 c and one or more internet service provider 42 d.
[0029] In accordance with a preferred embodiment of the present invention, each CSP 42 may operate and maintain a database 52 and a router 54 . The data in each database 52 of each CSP 42 may include the names of the businesses served by the CSP, the full-length contact details assigned to each business by the CSP, and the compact contact details assigned to each business by the CSP. In accordance with a preferred embodiment of the present invention, compact contact details coordination unit (CCDCU) 40 may coordinate the availability of communications nicknames for assignment to businesses 44 with CSPs 42 . A unique communications nickname may be assigned to a business 44 when it is determined by CCDCU 40 , through examination of all databases 52 , that the nickname has not been assigned to any other business.
[0030] When a communication is initiated by a customer using a compact CAN, the CSP 42 handling the communication may employ its muter 54 to route the communication to its correct destination according to the data stored in its database 52 .
[0031] For example, as shown in FIG. 3 , innovative CAN “*2879” may* be associated with prior art address 14 of business 44 in the post office database, so that the post office may forward deliveries addressed to “*2879” to the Glass Building offices of business 44 . Such a forwarding may be through a mechanism similar to the mail forwarding mechanism currently available from post offices. Alternatively, post office 42 a may have a more sophisticated method for collecting mail addressed to a communications nickname.
[0032] Telephone company 42 b may route voice calls placed to “*2879” to telephone number 16 . For facsimiles sent to CAN *2879, when telephone company 42 b detects the sounds of a facsimile machine, it routes the phone call to fax number 18 for the business associated with *2879.
[0033] Cellular phone call carriers may similarly maintain databases to route calls received to innovative CANs. The routing of telephone calls of any kind may be according to existing call forwarding mechanisms. Alternatively, many telephony service providers include the ability to mute *xxxx type phone numbers and thus, may utilize this option. Other mechanisms for routing CAN *2879 may also be available and are included in the present invention.
[0034] In accordance with a preferred embodiment of the present invention, customers may also use the communications nickname “*2879” to contact business 44 by text message (SMS). The service provider for the text messages (e.g. a cellular telephone operator 42 c , internet service provider 42 d ) may route text messages addressed to compact contact access numbers to an account on an internet server, such as one provided by Cellact of Raanana, Israel, where the text messages may be retrieved by business 44 , or they may be forwarded to an account accessed on a computer located at business 44 .
[0035] In accordance with a preferred embodiment of the present invention, customers may also type the communications nickname “*2879” into a web browser and may be routed to the website of business 44 . An exemplary muting mechanism may be available through the combined operation of two applications, Netex of Israel and bweb.co.il of Israel. Netex may translate communications nicknames to the bweb.co.il website and the bweb.co.il website, through its associated database 52 , may translate input phone numbers, such as the communications nickname, to regular URLs, such as the actual website address of the company.
[0036] In accordance with a preferred embodiment of the present invention, customers may also send emails to business 44 at an address containing the communications nickname of business 44 . As shown in FIG. 2 , an email address for business 44 may include a domain name (i.e. “csp.com”) in addition to its communications nickname. Emails addressed to “*2879.csp.com” may be forwarded by the server receiving these emails to a different email address designated by business 44 . In a database 52 associated with the email server, each business 44 may be associated with its communication nickname, and the forwarding email address for business 44 .
[0037] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A method including providing a business with a unified communications number for all types of customer communication and mapping the unified communications number to each address for the business issued by the communication service providers of the business. The method may also include routing communications addressed to the unified communications number to the appropriate the address as a function of the type of communication. | 6 |
This invention relates to a coupling, a hose and coupling assembly and to a method of forming the same, and particularly relates to the coupling of heavy duty hose having multiple plies of steel reinforcing elements.
Hose and coupling assemblies intended for heavy duty use such as rotary drilling, choke and kill, and motion compensator hoses require reliability of sealing between the hose and the coupling in order to withstand working pressure which may exceed 10,000 psi. In addition, in certain heavy duty applications the hose may be subjected to external end loads which may exceed 120,000 pounds. These end loads may be applied either when the hose is pressurized or not pressurized. Unpressurized is the more severe condition for hose to coupling retention. An example of the latter condition occurs in hose-coupling assemblies used for supplying high pressure water for an underwater trenching platform, called a jetting sled, which uses very high pressure water to blast a pipeline trench in the sea floor. The jetting sled is dragged along the sea floor by large drag cables connected to a surface ship. The jetting hose is also connected to the sled. Slackening of the drag cables may cause the hose to periodically be the main dragging link with the sled. This tremendous end loading may occur when the hose is pressurized or unpressurized. The coupling assembly of this invention is capable of withstanding these end load conditions. The hose, coupling combination of this invention achieves both reliable end seal under substantial working pressure and the ability to withstand very large end loadings either with or without internal working pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cut-away sectional view axially through a coupling of the invention.
FIG. 2 is a partial cut-away sectional view axially through a hose and coupling assembly which depicts a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the coupling 1 which is a two part fitting. The stem 2 and the ferrule 3 are fabricated from suitable rigid metal or high performance reinforced plastic. The stem 2 is a generally cylindrical body with a smooth circular bore 4 extending therethrough, having a smaller outside diameter end 5 containing an annular recess 6 therein and a large diameter end 7. The smaller diameter end 5 has adjacent thereto a smaller diameter portion 8 of the outer surface of the stem. The larger diameter end 7 similarily has a larger diameter portion 9 of the outer surface of the stem adjacent thereto. The smaller diameter portion 8 of the stem includes over a substantial portion of its outer surface a series of lands 61 and grooves 60 which are necessary for fitting retention when a hose is coupled with the coupling 1. The ferrule 3 is a rigid generally tubular sleeve having an inner diameter equal to the diameter of the larger diameter end 5 of the stem 2 and longer in axial length than the smaller diameter portion 8 of the stem. The ferrule 3 is slidably mounted over the larger diameter end 7 of the stem 2 and coaxially positioned such that at least some portion is overlapping and in contact with the larger diameter portion 9 of the stem and the rest extends over the full length of the smaller diameter portion 8 of the stem. It is desired that the coupling be adapted to provide a means to overlap the cover of a hose onto the ferrule to accomplish a smooth transition onto the coupling, the outer surface of the ferrule may be gradually tapered toward the end which will abut the hose.
Referring to FIG. 2 there is shown a preferred hose and coupling assembly 10 having a longitudinal axis depicted by line 2--2. When the term coaxial is used herein, it will mean that the particular feature is coaxial with respect to this longitudinal axis 2--2. The hose 12 includes an elastomeric tube 13 which forms its radially innermost surface. Overlying the tube 13 may be multiple plies 17 of textile reinforcement embedded in elastomeric material. Overlying the tube 13 and textile ply 17 are at least two layers 18, 19 of main reinforcing elements such as steel or aromatic polyamide cables 20. Each of the cables 20 is typically comprised of a plurality of filaments of high tensile steel wire, or aromatic polyamide polymer. Cables 20 are helically wound about the tube 13 and the reinforcement plies 17. The cables 20 of the radially innermost layer 18 are helically wound in an opposite sense relative to those of the adjacent radially outermost layer 19 of steel cables 20. Overlying the steel cables 20, there may optionally be one or more layers of outer fabric plies 24 which are embedded in an elastomeric material. Overlying the outer fabric plies 24 is a cover layer 25 of elastomeric material which forms the outer surface 26 of the hose 12. It is desirable to immobilize the steel cables 20 of the reinforcement layers 18 and 19 to assure that there is no flaring outwards during coupling operations. A cable holddown strip 22 is shown in FIG. 2 and is useful for the purpose of maintaining the compact cylindrical structure of the reinforcement elements. Other means such as circumferential wire wrapping may be used as a hold down strip as well.
The coupling 14 is a preferred embodiment of the coupling 1 of FIG. 1. Coupling 14 is a two part fitting including a stem 15 and a ferrule 16. The stem 15 and ferrule 16 are machined separately from pieces of suitable rigid material, preferably steel. The stem 15 inc1udes a bore 30 which is circular in cross-section and has an axis 2--2. The stem 15 has a hose engaging end 31 and a nipple end 32. The hose engaging end 31 includes an annular recess 33 having a mean diameter slightly greater than said stem bore 30. The outside diameter of stem 15 at the nipple end 32 is greater than the diameter at the hose engaging end 31. Preferably the difference between the diameters is approximately equal to two times the radial thickness of the reinforcing element layers 18, 19. A ferrule engaging rib 34 is provided on the outer surface of stem 15. The ferrule engaging rib 34 is spaced axially away from the nipple end 32 and is in the form of a raised annular ring surrounding the stem. The edge of the rib facing the nipple end 32 is preferably a flat facing surface. Rib 34 may be machined as an integral part of the stem 15 as illustrated in FIG. 2. The rib may also be formed by alternate means (not shown) such as a snap ring which fits into an annular groove formed in the outer surface of the stem 15. The shoulder 35 between the larger diameter nipple. end of stem 15 and smaller diameter hose engaging end 31 is shown for illustrative purposes in FIG. 2 as being a tapered shoulder. This shoulder 35 may be any suitable configuration, including a squared-off shoulder or a stairstep shoulder.
The ferrule 16 is a generally cylindrical body having a coaxial bore 42 with a diameter equal to the diameter of stem 15 at the point where rib 34 rises from the main body of the stem. The ferrule 16 has a stem engaging end 41 and a tapered end 45. Ferrule 16 also has a coaxial counter-bore 43 with a diameter equal to the diameter of the ferrule engaging radial rib 34 of the stem 15. The maximum extent of the counter-bore 43 is defined by a rib engaging shoulder 44 which engages the radial rib 34 when the ferrule 16 is slidably positioned on stem 15. The outside diameter of the ferrule 16 being a gradual outside taper toward the tapered end 45 which is opposite the stem engaging end 41. The ferrule 16 may include at least one port 46 which is a bore extending radially through the ferrule 16.
The outer surface of the stem extending from the shoulder 35 toward the hose engaging end of the stem 31 and the innermost surface of the ferrule counter-bore 43 is configured, for example, with a plurality of lands 47 and grooves 48 to provide secure anchorage of the coupling to the anchoring material such as epoxy resin. These surfaces may also be textured or treated for improved adhesion. FIG. 2 illustrates the preferred embodiment of land and groove which is a continuous spiral stem thread 36 and a continuous spiral ferrule thread 49, where both threads have a rectangular bottom.
The hose 12 and coupling 14 may be combined to form a hose and coupling assembly 10 having superior end pull and end sealing capabilities. The multiple layers of hose reinforcing elements 18, 19 are positioned between the stem portion 15 and the ferrule portion 16 of the coupling 14. The reinforcing layers 18 and 19 have a maximum extent at the point at which the rib engaging shoulder 44 of the ferrule is in contact with the ferrule engaging radial rib 34 of the stem portion. FIG. 2 shows the preferred embodiment of the invention wherein the reinforcing layers 18, 19 terminate short of the shoulder 35 of the stem portion. The recess 33 in the hose engaging end of stem 31 is filled with an elastomeric sealing material 27 which is preferably of the same composition as the tube 13 or at least is capable of being covulcanized into an integral cured unit. The elastomeric sealing material 27 may be an extension of uncured tube 13 which has been folded on itself or it may be a separately applied body of uncured elastomer. The textile plies 17 extend to a point near recess 33, but not adjacent thereto. The elastomeric sealing material 27 lies between the textile plies 17 and the hose engaging end of stem 31. FIG. 2 shows a preferred embodiment in which at least one fabric reinforcing ply 17 extends axially past the end of stem 15. This preferred configuration assures that in the presence of twisting motion between the hose and the coupling that a firm end seal is maintained through the mechanical bonding afforded by the textile reinforcement ply 17 extending through the maximum strain area which would be centered at the hose engaging end 31 of stem 15. The reinforcing elements 18 and 19 are embedded in an anchoring matrix 28. The anchoring matrix 28 completely surrounds the steel cables 20 and extends in the preferred embodiment shown in FIG. 1 into the stem threads 36 and ferrule threads 49. A preferred anchoring material is an epoxy resin.
A hose and coupling assembly 10 according to this invention may be made as follows: An uncured hose preform is fabricated on a cylindrical mandrel (not shown). The preform includes a radially innermost tube of uncured elastomeric material which will become the tube 13 of the completed hose 12, rubberized fabric reinforcing plies 17 wrapped about the uncured tube and at least two layers 18, 19 of main reinforcing elements composed of steel cables 20. The recess 33 is then filled with an uncured elastomeric sealing 27. This step may be accomplished by wrapping an uncured band of rubber over the mandrel such that the recess is filled. The cured band must be capable of forming an integral bond with the tube 13 during the subsequent curing step. An alternative method of filling the recess may be used. The uncured elastomer of the innerlayer of the hose preform may also be extended beyond the end of the fabric reinforcing layers 17 and rolled upon itself so as to form a volume of uncured elastomer sufficient to fill the recess 33 in stem 15 and form the elastomeric sealing material 27. The uncured hose preform is placed in end-wise contact with stem 15 such that the extension of the radially innermost elastomeric tube of the preform which extends beyond the end of the textile reinforcement plies 17 is set into the recess 33 of the stem 15. Axial pressure sufficient to force the extension of the elastomeric material of the innermost tube 13 to fill the recess is applied between the hose and the stem.
Once the uncured hose preform is in positive contact with stem 15, the main reinforcing elements such as steel cables 20 are extended onto the outer surface of the stem in such a manner that there is no substantial change in the mean diameter of the layers 18 and 19 as they are extended from the hose onto the stem. The steel cables 20 are then helically wound onto the stem until the helical layers of steel cable have extended at least to the juncture 35 in the stem 15. The steel cables are then securely bound by a hold-down means such as the cable hold-down strip 22 shown in FIG. 2. The portions of the steel cables 20 which extend onto the shoulder area are then cut off in order to terminate the steel cable layer just short of the shoulder 35. Any cables extending into the shoulder area and onto the larger diameter portion of the stem are removed. The ferrule 16 is then slid onto the stem portion from the nipple end 32 such that the tapered end 45 of the ferrule is extending over the reinforcing elements 18 and 19. The ferrule is slid onto the stem until the rib engaging shoulder 44 is firmly in contact with the ferrule engaging radial rib 34 of the stem. A suitable means for sealing is set in place at the tapered end of the ferrule so as to occlude the passage of any fluid and form a void annular area of space between the ferrule 16 and the hose preform. FIG. 2 illustrates one suitable means for sealing which is a dam 51 which is composed of rubber covered fabric strips which are wrapped around the circumference of the assembly to form the annular space or void. The anchoring material 28 is then introduced through at least one port 46 into the annular void space between the axial counter-bore 43 of the ferrule and the exterior surface of the stem extending from the radial rib 34 toward the hose engaging end 31 of the stem. It should be noted here that when a liquid anchoring material 28 such as an epoxy resin is utilized, it migrates between the individual steel cables and completely fills the void area between the ferrule and the stem through to the dam 51. The anchoring material 28 solidifies and thus anchors the steel cables 20 to the coupling 14. Thereafter the radially outer most elastomeric cover layer 26 is applied over the complete exterior of the hose and is extended onto the outer surface of the ferrule 16 to completely cover the tapered end 45 of the ferrule 16. The cover layer 26 extends partly over the coupling 14 in order to provide a uniform diameter assembly so that snagging of that assembly in service is minimized. After completion of assembly of the uncured hose and curing or solidification of the anchoring material such as epoxy resin, the hose and coupling assembly 10 is cured by applying heat and pressure in a conventional manner to effect vulcanization of the elastomeric components of the hose preform and to securely bond the elastomeric sealing material 27 to the hose tube 13 and to the adjacent surfaces of coupling 14.
In many working environments there may be applied a twisting moment to the hose and coupling combination which would transmit considerable shear stress to the interface between the hose engaging end 31 of stem 15 and the elastomeric sealing material 27 adhered thereto. Any dislocation of the sealing material may cause leakage between the coupling and the hose. The portion of the stem which contacts this elastomeric material 27 may be cleaned by sand or bead blasting prior to assembly. A known adhesion promoter such as Chemlock™ 205 and 220 in combination, available from Hughson Chemical Corporation may also be utilized as is well known to enhance the adhesion at this critical end seal interface. The building method may preferably include the additional step that at least one textile fabric reinforcement layer 17 be extended past the hose engaging end 31 onto the main body of the stem. This extension of the fabric reinforcement layer 17 through this critical stress interface provides a means for dissipating the shear stress of such twisting away from the end seal area of the hose. The configuration of the recess 33 is shown as a generally U-shaped configuration, but it can be machined to many configurations to assure a good end seal as is taught in U.S. Pat. No. 4,353,581.
The elastomers useful in the tube, cover and elastomeric sealing material, are any of the well known rubber polymers including natural rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubbers, polychloroprene, polyisoprene, ethylene-propylene diene, polybutadiene. The preferred embodiment shown in FIG. 2 was made with an innermost tube and elastomeric sealing material of acrylonitrile-butadiene copolymer with carbon black loading. The cover was a carboxylated acrylonitrile-butadiene compound with carbon black and silica loading.
An 8 inch (20 cm) internal diameter 25 foot (7.6 m) jetting hose and coupling assembly was made according to the method described conforming to the embodiment shown in FIG. 2. The nipple end of the coupling was welded to a flange and connected to a compressor. The hose was pressurized to 2500 psi (17.4 MPa). The pressurized hose was subjected to an end loading (axial pull) of 120,000 foot pounds (534 kN). Despite a lengthening of 25 inches (64 cm), the hose-coupling assembly maintained the internal pressure during the end loading test pull indicating that the hose-to-coupling seal was intact. The internal pressure rose to 4500 psi (31 MPa) at 120,000 foot pounds (534 kN) of end pull due primarily to volumetric changes in the hose. The hose coupling assembly of this invention was found to be capable of withstanding internal pressurization in excess of 10,000 psi (69 MPa).
While certain representative embodiments and details have been shown for the purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention. | The coupling has a stem and a ferrule. The stem is placed against an uncured hand-built steel cable reinforced hose. The steel reinforcement cable is spiraled onto a smaller diameter portion of the stem. The ferrule is then slid over the stem and over the reinforcing cable layers. Epoxy resin is injected through ports in the ferrule to embed the reinforcing cables and securely fix the hose structure to the stem and ferrule of the coupling. A cover is applied over the ferrule. The hose-coupling assembly is subjected to heat and pressure to cure the elastomeric portions of the hose and securely bond them to the surfaces of the coupling. The hose-coupling assembly is useful in very heavy duty applications where the assembly must withstand large end load strains when the hose is not under internal pressure, such as hose for use on a jetting sled. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments described herein relate generally to improved semiconductor imaging devices and in particular to imaging devices having an array of pixels and to methods of operating the pixels to reduce temporal noise.
[0003] 2. Background of the Invention
[0004] A conventional four transistor (4T) circuit for a pixel 150 in a pixel array 230 of a CMOS imager is illustrated in FIG. 1 . The 4T pixel 150 has a photosensor such as a photodiode 162 , a reset transistor 184 , a transfer transistor 190 , a source follower transistor 186 , and a row select transistor 188 . It should be understood that FIG. 1 shows the circuitry for operation of a single pixel 150 , and that in practical use, there will be an M×N array of pixels arranged in rows and columns with the pixels of the array 230 being accessed using row and column select circuitry, as described in more detail below.
[0005] The photodiode 162 converts incident photons to electrons, which are selectively passed to a floating diffusion region A through the transfer transistor 190 when activated by a TX1 control signal. The source follower transistor 186 has its gate connected to floating diffusion region A and thus amplifies the signal appearing at the floating diffusion region A. When a particular row containing pixel 150 is selected by an activated row select transistor 188 , the signal amplified by the source follower transistor 186 is passed on a column line 170 to column readout circuitry ( 242 , FIGS. 2-4 ). The photodiode 162 accumulates a photo-generated charge in a doped region of its substrate during a charge integration period. It should be understood that the pixel 150 may include a photogate or other photon to charge converting device, in lieu of a photodiode, as the initial accumulator for photo-generated charge.
[0006] The gate of transfer transistor 190 is coupled to a transfer control signal line 191 for receiving the TX1 control signal, thereby serving to control the coupling of the photodiode 162 to region A. A voltage source Vpix is selectively coupled through reset transistor 184 and conductive line 163 to floating diffusion region A. The gate of the reset transistor 184 is coupled to a reset control line 183 for receiving a RST control signal to control the reset operation in which the voltage source Vpix is connected to floating diffusion region A.
[0007] A row select signal (Row Sel) on a row select control line 160 is used to activate the row select transistor 188 . Although not shown, the row select control line 160 , reset control line 183 , and transfer signal control line 191 are coupled to all of the pixels of the same row of the array. The voltage source Vpix is coupled to transistors 184 and 186 by conductive line 195 . The column line 170 is coupled to the output of all of the pixels of the same column of the array and typically has a current sink 176 at one end. Signals from the pixel 150 are selectively coupled to a column readout circuit 242 ( FIGS. 2-4 ) through the column line 170 .
[0008] As is known in the art, a value can be read from pixel 150 in a two step correlated double sampling process. First, floating diffusion region A is reset by activating the reset transistor 184 . The reset signal (e.g., Vrst) found at floating diffusion region A is readout to column line 170 via the source follower transistor 186 and the activated row select transistor 188 . During a charge integration period, photodiode 162 produces charge from incident light. This is also known as the image intergration period. After the integration period, the transfer transistor 190 is activated and the charge from the photodiode 162 is passed through the transfer transistor 190 to floating diffusion region A, where the charge is amplified by the source follower transistor 186 and passed to the column line 170 (through the row select transistor 188 ) as an integrated charge signal Vsig. In some instances, the reset signal Vrst is provided after the integrated charge signal Vsig. As a result, two different voltage signals—the reset signal Vrst and the integrated charge signal Vsig—are readout from the pixel 150 onto the column line 170 and to column readout circuitry 242 , where each signal is sampled and held for further processing as is known in the art. Typically, all pixels in a row are readout simultaneously onto respective column lines 170 and the column lines may be activated in sequence or in parallel for pixel reset and signal voltage readout.
[0009] FIG. 2 shows an example CMOS imager device 201 that includes the pixel array 230 and a timing and control circuit 232 , which provides timing and control signals to enable reading out of signals stored in the pixels in a manner commonly known to those skilled in the art. Example arrays have dimensions of M×N pixels, with the size of the array 230 depending on a particular application. In the illustrated imager device 201 , the pixel signals from the array 230 are readout a row at a time using a column parallel readout architecture. The controller 232 selects a particular row of pixels in the array 230 by controlling the operation of row addressing circuit 234 and row drivers 240 . Reset Vrst and image Vsig signals in the selected row of pixels are provided on the column lines 170 to a column readout circuit 242 in the manner described above. The signals read from each of the columns can be readout sequentially or in parallel using a column addressing circuit 244 . Pixel signals (Vrst, Vsig) corresponding to the readout reset signal and integrated charge signal are provided as respective outputs Vout 1 , Vout 2 of the column readout circuit 242 where they are subtracted in differential amplifier 246 , digitized by analog-to-digital converter (ADC) 248 , and sent to an image processor circuit 250 for image processing.
[0010] FIG. 3 shows more details of one example of the arrangement of the rows and columns 249 of pixels 150 in the array 230 . Each column 249 includes multiple rows of pixels 150 . Signals from the pixels 150 in a particular column 249 can be readout to sample and hold circuitry 261 associated with the column 249 (part of circuit 242 ) for acquiring the pixel reset Vrst and integrated charge Vsig signals. Signals stored in the sample and hold circuits 261 can be read sequentially column-by-column to the differential amplifier 246 ( FIG. 2 ), which subtracts the reset and integrated charge signals and sends them to the analog-to-digital converter 248 ( FIG. 2 ). Alternatively, a plurality of analog-to-digital converters 248 may also be provided, each digitizing sampled and held signals from one or more columns 249 .
[0011] FIG. 4 illustrates portions of three sample and hold circuits 261 of FIG. 3 in greater detail. Each sample and hold circuit 261 holds a set of signals, e.g., a reset signal Vrst and an integrated charge signal Vsig from a desired pixel. For example, a reset signal Vrst of a desired pixel connected to column line 170 is stored on capacitor 226 and the integrated charge signal Vsig from column line 170 is stored on capacitor 228 . A front side of capacitor 226 is switchably coupled to the column line 170 through switch 222 and a backside of capacitor 226 is switchably coupled to amplifier 248 through switch 218 . A front side of capacitor 228 is switchably coupled to the column line 170 through switch 220 and a backside of capacitor 228 is switchably coupled to amplifier 248 through switch 216 . The front side of capacitor 226 is switchably coupled to the front side of capacitor 228 through crowbar switch 239 . The backside of capacitor 226 is switchably coupled to the backside of capacitor 228 and to a reference voltage Vref source through clamp switch 299 .
[0012] Each sample and hold circuit 261 is coupled to amplifier 248 having first and second inputs. The first input of amplifier 248 is coupled to a first output of amplifier 248 through a capacitor 278 and a switch 279 to provide a first feedback circuit. The second input of amplifier 248 is coupled to a second output of amplifier 248 through a capacitor 276 and a switch 277 to provide a second feedback circuit.
[0013] The CMOS imager of FIGS. 1-4 has identical correlated double sampling and holding timing for all columns over an entire row. Thus, all of the pixels in a row are readout at substantially the same time. The simplified correlated double sampling and column read out timing is depicted in FIG. 5 .
[0014] Thus, to begin a readout operation, a logic high clamp signal cl is provided to clamp switch 299 thereby coupling the backsides of capacitors 226 , 228 to a reference voltage source Vref. When a reset signal Vrst is read from the pixel 150 , a logic high SHR signal is provided to the gate of switch 222 thereby coupling the front side of capacitor 226 to the column line 170 . When the readout of the reset signal Vrst from the pixel 150 is complete, a logic low SHR signal is provided to the gate of switch 222 thereby uncoupling the front side of capacitor 226 from the column line 170 . Thus, a reset signal Vrst has been sampled and stored on capacitor 226 .
[0015] After the reset Vrst signal is read from pixel 150 , an integrated charge signal Vsig is readout. When the integrated charge signal Vsig is read from pixel 150 , a logic high SHS signal is provided to the gate of switch 220 thereby coupling the front side of capacitor 228 to the column line 170 . When the readout of the integrated charge signal Vsig from the pixel 150 is complete, a logic low SHS signal is provided to the gate of switch 220 thereby uncoupling the front side of capacitor 228 from the column line 170 . Thus, an integrated charge signal Vsig has been sampled and stored on capacitor 228 .
[0016] When the readout operation is complete, a logic low clamp signal cl is provided to clamp switch 299 thereby uncoupling the backsides of capacitors 226 , 228 from the reference voltage source Vref.
[0017] After a row of pixels has been readout, sampled, and held, then, generally in column order, the sample and hold circuits 261 output their stored signals to the amplifier 248 . When reading from a first sample and hold circuit 261 , a logic high control signal Φamp is provided to the feedback circuits to close switch 279 to couple the first output of amplifier 248 through capacitor 278 to its first input and to close switch 277 to couple the second output of amplifier 248 through capacitor 276 to its second input. A logic high crowbar control signal, e.g., crowbar 1 for the sample and hold circuit 261 associated with the first column, is also provided to the sample and hold circuit 261 being readout to close the associated crowbar switch 239 , thereby coupling the front side of capacitor 226 to the front side of capacitor 228 . A logic high control signal, e.g., c 1 for the sample and hold circuit 261 associated with the first column, is also provided to the sample and hold circuit 261 being readout to close switch 218 and switch 216 , thereby coupling the backside of capacitor 226 to the first input of amplifier 248 and coupling the backside of capacitor 228 to the second input of amplifier 248 .
[0018] After the reset and integrated charge signals have been readout to amplifier 248 , a logic low control signal (Damp is provided to the feedback circuits to open switch 279 and uncouple the first output of amplifier 248 from capacitor 278 and to open switch 277 and uncouple the second output of amplifier 248 from capacitor 276 . A logic low crowbar control signal (e.g., crowbar 1 for the first column) is provided to the sample and hold 261 being readout to open the associated crowbar switch 239 , thereby uncoupling the front side of capacitor 226 from the front side of capacitor 228 . A logic low control signal e.g., c 1 , is also provided to the sample and hold 261 being readout to open switch 218 and switch 216 , thereby uncoupling the backside of capacitor 226 from the first input of amplifier 248 and uncoupling the backside of capacitor 228 from the second input of amplifier 248 . Thus, a correlated double sampled signal is provided as output from amplifier 248 resulting from the input of the integrated charge and reset signals to the amplifier 248 . After a row of sample and hold circuits 261 have been readout, a next of row of pixels 150 in the pixel array 230 are sample, held, and then readout through the amplifier 248 .
[0019] FIG. 6 illustrates a modified pixel array 230 ′ that uses 4-way shared pixel circuitry comprising four pixels in neighboring columns and which desirably omits a row select transistor in the readout circuit for the shared pixel circuits. The pixel array 230 ′ is an alternative to the pixel array 230 . The pixel array 230 ′ is comprised of even columns that include pixels 450 a - d and odd columns that include pixels 451 a - d. Although pixel array 230 ′ is depicted as including three columns and four rows, the pixel array 230 ′ is representative of a pixel array having any plurality of rows and columns. The columns of the pixel array 230 ′ are labeled Y(m+1), Y(m), and Y−1(m+1) and the rows of pixel array 230 ′ are labeled X(n), X(n+1), X(n+2), and X(n+3).
[0020] In array 230 ′ pixels are diagonally grouped by color into a pixel circuit; thus, green pixels are grouped together and blue and red pixels are grouped together. A green pixel circuit, for example PixelCircuit 1 , is comprised of pixels 451 a, 450 b, 451 c, and 450 d . The green pixel circuit PixelCircuit 1 also includes a reset transistor 484 and a source follower transistor 486 . A blue and red pixel circuit, for example PixelCircuit 2 , is comprised of pixels 450 a, 451 b , 450 c, and 451 d. The blue and red pixel circuit PixelCircuit 2 also includes a reset transistor 485 and a source follower transistor 487 . In operation, the green pixel circuit PixelCircuit 1 is readout, row by row, through a single column line, e.g., Col Y(m+1) and the blue and red pixel circuit PixelCircuit 2 is readout, row by row, through a single column line, e.g., Col Y(m). No row select transistors are used in the readout circuit to couple the source follower transistors 486 , 487 to a column line.
[0021] Pixel array 230 ′ also includes transfer transistor control lines associated with each row of the array 230 ′, e.g., TX X(n) for pixels in row X(n) associated with transfer transistors 490 a and 491 a . Additionally, pixel array 230 ′ includes reset transistor control lines associated with each group of four rows of the array, e.g., RST X(n) for pixels in rows X(n), X(n+1), X(n+2), and X(n+3), associated with reset transistors 484 , 485 . Moreover, pixel array 230 ′ includes column pull up (Col_Pu) transistors 498 to control coupling a Vaa-pix voltage to a column line 496 , 497 .
[0022] FIG. 7 depicts a simplified correlated double sampling and column read out timing for the pixel array 230 ′ of FIG. 6 . To begin a readout operation of a row X(n), at a time t 1 , a row address X(n) is provided to row addressing circuit 234 and column addressing circuit 244 of FIG. 2 . A Col_Pu signal is applied to transistors 498 to couple lines 496 , 497 to a voltage (e.g., Vaa-pix signal level) and therefore to activate the reset transistors 484 , 485 . At time t 2 , a logic high RST signal is provided to the reset line RST X(n), thereby placing a reset charge on one of a source or drain of reset transistors 484 , 485 . The floating diffusion regions 494 , 495 are reset by this operation. At time t 3 , a logic low Col_Pu signal is applied to transistors 498 to turn off transistors 498 and to deactivate reset transistors 484 , 485 , no longer resetting diffusion regions 494 , 495 . Time t 3 occurs approximately 250-750 ns after time t 2 occurs, preferably 500 ns.
[0023] At time t 4 , a logic high VLN_EN control signal is provided to the gates of column line transistors 491 , 492 , thereby creating a pull down circuit on the associated column lines, e.g., 496 , 497 . Time t 4 occurs 50-100 ns after time t 3 , preferably 70 ns. After time t 4 , a logic high SHR signal is strobed to sample and hold a reset signal Vrst readout of the floating diffusion regions 494 , 495 into sample and hold circuitry. The SHR strobe lasts approximately 1-2 μs, preferably 1.5 μs. A logic high TX(n) then is strobed, which closes transfer transistors 491 a, 490 a and couples the photodiodes 462 to their associated floating diffusion regions 494 , 495 , thereby transferring the accumulated charge from the photodiode 462 to their associated floating diffusion regions 494 , 495 . The TX strobe lasts approximately 500-1000 ns, preferably 750 ns, ending at time t 5 . A logic high SHS signal is strobed to sample and hold accumulated charge read from the floating diffusion regions 494 , 495 into sample and hold circuitry. The SHS signal begins to be strobed before the TX strobe has completed, e.g., before time t 5 . The strobe of the SHS signal lasts approximately 1-2 μs, preferably 1.5 μs and ends at time t 6 . At time t 7 , a logic low VLN_EN signal is provided thereby no longer creating a pulldown circuit on the associated column line. Time t 7 occurs approximately 50-100 ns, preferably, 70 ns, after time t 6 , e.g., the completion of the SHS strobe. Subsequently, a logic high Col_Pu signal and a logic low RST(n) signal are provided. Thus, a reset signal and a charge accumulation signal are sampled from the pixel array 230 ′.
[0024] At t 8 , a rolling shutter operation occurs. A row address X(n+m) is provided to row addressing circuit 234 and column addressing circuit 244 of FIG. 2 , which is used for a rolling shutter. After time t 8 , a logic high RST(n+m) signal and a logic high TX(n+m) are provided. The strobe of the TX(n+m) signal occurs while the RST(n+m) is provided with a logic high signal. After the rolling shutter operation ends, e.g., at time t 9 , the next row of the pixel array is sampled, e.g., row n+1. The pixel array continues to be readout, row by row, until substantially all of the rows of the pixel array have been readout. Thus, a reset signal and a charge accumulated signal are read out from the pixel array. Further, a rolling shutter has been toggled.
[0025] With the pixel array 230 ′ ( FIG. 6 ) PixelCircuit 1 , PixelCircuit 2 , are comprised of zigzagged pixels in two neighboring columns, so the pixel circuits are asymmetric and are difficult to significantly reduce in size.
[0026] It is desirable to have a shared pixel circuit that is more compact and of reduced size.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic diagram of a conventional imager pixel.
[0028] FIG. 2 is a block diagram of a conventional imager device.
[0029] FIG. 3 is a block diagram of a portion of an array of pixels illustrated in
[0030] FIG. 2 and an associated column readout circuit.
[0031] FIG. 4 is a conventional sample and hold circuit.
[0032] FIG. 5 is a simplified timing diagram associated with operation of the circuitry of FIGS. 1-4 .
[0033] FIG. 6 is a block diagram of a diagonally shared pixel circuit.
[0034] FIG. 7 is a simplified timing diagram associated with operation of the circuitry of FIG. 6 .
[0035] FIG. 8 is a block diagram of a vertically shared pixel circuit in accordance with an example embodiment disclosed herein.
[0036] FIG. 9 is simplified timing diagram associated with operation of the circuitry of FIG. 8 .
[0037] FIG. 10 is a block diagram representation of a processor-based camera system incorporating a CMOS imaging device in accordance with an embodiment disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0038] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use them, and it is to be understood that structural, logical, or procedural changes may be made.
[0039] Embodiments described herein provide a shared pixel circuit which omits a row select transistor in the readout circuit of a shared pixel and which reduces the size and complexity required by the shared pixel array depicted in FIG. 6 . By providing a vertically shared (i.e., within the same column) pixel circuit, the overall size of the pixel array can be reduced. With a pixel circuit being shared vertically instead of across columns, associated readout circuitry is less complex. Thus, pixel circuits are symmetrical and can be reduced in size. Furthermore, the pixel circuits can also be readout quicker than the pixel circuit of FIG. 6 .
[0040] FIG. 8 illustrates a pixel array 800 comprising vertically 4-way shared pixel circuitry, each comprising four pixels in a same column in accordance with an example embodiment. The pixel array 800 is comprised of even columns that include pixels 850 a - d and odd columns that include pixels 851 a - d . Although pixel array 800 is depicted as including three columns and four rows, the pixel array 800 is representative of a pixel array having any plurality of rows and columns. The columns of the pixel array 800 are labeled Y(m+1), Y(m), and Y−1(m+1) and the rows of pixel array 800 are labeled X(n), X(n+1), X(n+2), and X(n+3).
[0041] In illustrated embodiment, pixels are vertically grouped by column into a shared pixel circuit; thus, four pixels in a column are grouped together. A first shared pixel circuit, for example PixelCircuit 1 ′, is comprised of pixels 850 a, 850 b, 850 c, and 850 d. The first pixel circuit PixelCircuit 1 ′ also includes a reset transistor 884 and a source follower transistor 896 . PixelCircuit 1 ′ does not include a row select transistor. A second shared pixel circuit, for example PixelCircuit 2 ′, is comprised of pixels 851 a, 851 b, 851 c, and 851 d. The second pixel circuit PixelCircuit 2 ′ also includes a reset transistor 885 and a source follower transistor 897 and does not include a row select transistor.
[0042] Each shared pixel circuit, e.g., PixelCircuit 1 ′ has a plurality of pixels, and at least two of the plurality of pixels are of a same color. For example, as depicted in FIG. 8 , PixelCircuit 1 ′ includes two green pixels 850 b, 850 d. Additionally, PixelCircuit 1 ′ includes two pixels of a second same color, e.g., pixels 850 a, 850 c are red. Similarly, PixelCircuit 2 ′ includes two green pixels 851 a, 851 c and two blue pixels 851 b , 851 d. All of the plurality of pixels of the shared pixel circuit are in a same column of pixels. For example, the pixels of PixelCircuit 1 ′ are all in column Y(m+1). Each column of pixels in array 230 ′ includes a plurality of pixel circuits.
[0043] In an aspect, the pixel array 800 includes a plurality of ground (GND) lines that run in a vertical direction of the array. These ground lines are connected throughout the array 800 at various locations to a ground source. Including a plurality of GND lines that are relatively locally connected to a ground source reduces noise. Pixel array 800 includes column pull up (Col_Pu) transistors 498 to control coupling a Vaa-pix voltage to a column line 488 , 489 .
[0044] FIG. 9 depicts a simplified correlated double sampling and column read out timing for the pixel array 800 of FIG. 8 . To begin a readout operation of a row X(n), at a time t′ 1 , a row address X(n) is provided to row addressing circuit 234 and column addressing circuit 244 FIG. 2 . At time t′ 2 , a logic high RST signal is provided to the reset line RST X(n), thereby placing a charge on one of a source or drain of reset transistors 884 , 885 . The floating diffusion regions 494 , 495 are reset. At time t′ 3 , a logic high Col_PU signal is provided to transistors 498 thereby coupling the lines 488 , 489 to a voltage, e.g., Vaa_pix voltage level and enabling diffusion regions 494 , 495 to be reset (via the reset transistors 884 , 885 ). In an aspect, time t′ 3 occurs approximately 250-750 ns after time t′ 2 occurs, preferably 500 ns. Before time t′ 4 occurs, a logic low Col_Pu signal is provided to transistors 498 thereby uncoupling the lines 488 , 489 from the voltage, e.g., Vaa_pix voltage level, and disabling diffusion regions 494 , 495 from being further reset.
[0045] At time t′ 4 , a logic high VLN_EN control signal is provided to the gates of transistors 491 , 492 thereby creating a pull down circuit on the associated column lines, e.g., 488 , 489 . In one aspect, time t′ 4 occurs approximately 50-100 ns after time t 3 , preferably 70 ns. After time t′ 4 , a logic high SHR signal is strobed to sample and hold a reset signal read from the floating diffusion regions 494 , 495 into a sample and hold circuit. In an aspect, the SHR strobe lasts approximately 1-2 μs, preferably 1.5 μs. A logic high TX(n) is strobed which closes transfer transistors 891 a, 890 a and couples the photodiodes 462 to their associated floating diffusion regions 494 , 495 transferring the accumulated charge from the photodiodes 462 to their associated floating diffusion regions 494 , 495 . In an aspect the TX(n) strobe lasts approximately 50-100 ns, preferably 70 ns, and ends at time t′S. A logic high SHS signal is strobed to sample and hold the accumulated charge read from the floating diffusion regions 494 , 495 into a sample and hold circuit. In a preferred approach, the SHS signal begins to be strobed before time t′S, e.g., before the TX(n) strobe has completed. In an aspect, the strobe of the SHS signal lasts approximately 1-2 μs, preferably 1.5 μs, and ends at time t′ 6 . At time t′ 7 , a logic low VLN_EN is provided thereby no longer creating a pulldown circuit on the associated column line. In an aspect time t′ 7 occurs approximately 50-100 ns, preferably, 70 ns, after the completion of the SHS strobe. Subsequently, a logic low RST(n) signal is provided. Thus, a reset signal and a charge accumulation signal are sampled from the pixel array. After that, the Col_Pu is enabled with RST(n) at low to reset the floating diffusion regions 494 , 495 to a low potential, which turns off the source follower transistor on the nth row.
[0046] At time t′ 8 , a rolling shutter operation begins. A row address X(n+m) is provided to row addressing circuit 234 and column addressing circuit 244 ( FIG. 2 ), which is used to implement a rolling shutter. After time t′ 8 , the logic high RST(n+m) signal and a logic high TX(n+m) are provided to reset the floating diffusion regions 494 , 495 and photodiodes 462 to a high potential and fully deplete the photodiodes 462 . In an aspect, the strobe of the TX(n+m) signal occurs while the RST(n+m) is provided with a logic high signal; the Col_Pu is high and keeps the RST (n+m) at low to turn off the source follower on the (n+m)th row. After an initial aspect of the rolling shutter operation ends at time t′ 9 , the next row of the pixel array is sampled, e.g., row n+ 1 . As conventionally known, the pixel array continues to be readout, row by row, until substantially all of the rows of the pixel array have been readout.
[0047] FIG. 10 is a block diagram representation of processor system that may include imaging device 1101 having the pixel array 800 ( FIG. 8 ) and associated readout circuitry as described with respect to the various embodiments described herein. The processor system could, for example, be a camera system 1190 . A camera system 1190 generally comprises a shutter release button 1192 , a view finder 1196 , a flash 1198 and a lens system 1194 for focusing an image on the pixel array 800 of imaging device 1101 . A camera system 1190 generally also comprises a central processing unit (CPU) 1110 , for example, a microprocessor for controlling camera functions which communicates with one or more input/output devices (I/O) 1150 over a bus 1170 . The CPU 1110 also exchanges data with random access memory (RAM) 1160 over bus 1170 , typically through a memory controller. The camera system 1190 may also include peripheral devices such as a removable memory 1130 , which also communicates with CPU 1110 over the bus 1170 . Imager device 1101 is coupled to the processor system and includes a pixel array 800 as described along with respect to FIGS. 8-9 . Other processor systems which may employ imaging devices 800 besides cameras, including computers, PDAs, cellular telephones, scanners, machine vision systems, and other systems requiring an imager operation.
[0048] While the embodiments have been described and illustrated with reference to specific example embodiments, it should be understood that many modifications and substitutions can be made. Although the embodiments discussed above describe specific numbers of transistors, photodiodes, conductive lines, etc., they are not so limited. For example, the above embodiments are not limited to vertical (single column) with internal reset and no row select of a 4 way shared pixel and could be applied to 2 way shared, 3 way shared, 5 way shared, etc. Accordingly, the claimed invention is not to be considered as limited by the foregoing description but is only limited by the scope of the claims. | A method and apparatus for reducing space and pixel circuit complexity by using a 4-way shared vertically aligned pixels in a same column. The at least four pixels in the pixel circuit share a reset transistor and a source follower transistor, can have a plurality of same colored pixels and a plurality of colors, but do not include a row select transistor. | 7 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part application based upon my copending application Ser. No. 620,070, filed June 13, 1984, and now abandoned, which was a continuation-in-part of my application Ser. No. 590,185, filed Mar. 16, 1984 and now abandoned, both entitled "Touch Controlled Switch For A Lamp Or The Like".
The present invention relates to an electronic power control device which is actuated by a person's touch and controls the electrical power to a lamp or another electrical load.
At the present time several "touch controlled lamp dimmers" are commercially available in which touching an electrically conductive part of the lamp causes the power level to the bulb to change, either continuously or in discrete steps. However, they all require a direct wire connection of the control device to the lamp and the mounting of the touch control device on the outside or inside of the lamp. Consequently, such presently available touch control devices can be used only with the lamps to which they are attached and electrically and/or mechanically connected.
OBJECTIVES AND FEATURES OF THE INVENTION
It is an objective of the present invention to provide an electrical power control device which operates by touch and which does not require a wired electrical connection to the lamp or appliance.
It is a further objective of the present invention that the control device be enclosed in a small box which may be plugged into a conventional wall socket and that the lamp will be plugged into the control device; so that any lamp can be converted at will to a touch controlled lamp without altering the lamp and without additional wiring.
It is a still further objective of the present invention to provide such a control device that will detect a capacitance change of the order of 1% when the operator touches the lamp, and which uses the lamp's own cord as the only means of communications to the control device.
It is a still further objective of the present invention to provide such a control device which is unaffected by, and immune to, false activation from the normal household current (50/60 cycle sine wave power) in the lamp cord; broadband radio frequency interference (RFI) spectrum as a result of triac control of power to the load; high ambient RFI environment and intermittent RFI; power line transients and power interruptions.
It is a still further objective of the present invention to provide such a control device which will have a low emitted RFI field intensity and harmonic spectrum, so as not to interfere with other electrical appliances.
It is a still further objective of the present invention to provide such a control device that will be relatively low in cost, highly reliable and may be manufactured by conventional electronic manufacturing plants and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objectives of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings.
In the drawings:
FIG. 1 is a schematic illustration of a prior art conventional incandescent lamp;
FIG. 2 is a circuit diagram indicating the capacitance relationship for an analysis of the present invention;
FIG. 3 is a schematic illustration of the basic operating principle of the present invention;
FIG. 4 is a block diagram illustrating the first embodiment of the present invention;
FIG. 5 is a circuit diagram used in explaining certain principles of the present invention;
FIG. 6 is a circuit diagram of the basic form of the oscillator circuit of the present invention;
FIG. 7 is a circuit diagram of a portion of the first embodiment of the present invention and relates to the sensing of the touch;
FIG. 8 is a circuit diagram of another portion of the first embodiment of the present invention and relates to the phase control;
FIGS. 9 and 10 are block diagrams of a second embodiment of the present invention which is a digital embodiment;
FIGS. 11, 11A and 12 are flow charts illustrating the software of the digital embodiment;
FIGS. 13 and 14 are circuit diagrams illustrating certain principles of the present invention; and
FIG. 15 is a detailed circuit diagram of the first embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The structure of a typical prior art incandescent lamp (lamp fixture) is shown in FIG. 1. The center tube 1, which is a metal tube, is the main structural support of the lamp. It is a conduit for the portion of lamp cord 2 which is within the lamp. The lamp socket 3 provides electrical contact to the bulb and is electrically isolated from the tube 1. The lamp cord 2 is typically a two-conductor parallel insulated wire.
The present invention uses the lamp cord 2 to communicate to the remote control device. There is no electrically conductive path between the lamp cord and the lamp structure in a properly wired lamp, i.e., there is no leakage of current from the line cord to the lamp. However, the lamp cord within the center tube 1 and center tube form an air dielectric capacitor. Thus, there is capacitive coupling between the lamp cord and the lamp.
The mechanism of touch sensing is made possible by electrically sensing a change in capacitance of the lamp when it is touched. When touched, the self capacitance of the lamp is augmented by the self capacitance of the body of the person touching the lamp.
An analytical model of the capacitances of interest is shown in FIG. 2, where: C A --capacitance of lamp cord; C B --capacitive coupling between lamp cord and lamp; C C --capacitance of lamp structure; C D --body capacitance of operator; and R D --resistance of contact point between lamp and operator.
The total capacitance of the lamp and cord is therefore:
C.sub.T =C.sub.A +(C.sub.B C.sub.C /C.sub.B +C.sub.C)
When the lamp is touched, this is increased to:
C.sub.T '=C.sub.A +[C.sub.B (C.sub.C +C.sub.D)/C.sub.B +C.sub.C +C.sub.D ]
assuming R D =0.
Typical capacitance values which have been measured are as follows: C A --25 pf (8 feet of 18 gauge lamp cord, conductors shorted); C D --65 pf (average man); C B --60 pf (1.5 feet of 0.25" ID steel tubing with 1.5 feet pf cord running through it); and C C --40 pf (typical metal lamp). Thus: C T =49 pf (approximately) and C T =63 pf (approximately), which represents a +28% change. In reality, RD does not equal zero but assumes a value from some hundreds of ohms to several megohms due to skin resistance and the varnish typically used on the metal portions of lamps. This increase in R D means that C D and consequently C T ' is decreased. Thus, the capacitance change, i.e., the difference between C T and C T ', can be as little as +1% in practice. The touch sense device must, therefore, respond to as little as a 1% change in capacitance when the lamp is touched. Earth ground is taken as the zero reference in this device, since the net charge of the earth is generally equal to zero and it is effectively an infinite source and sink for charge. Thus, the level of charge of an object, and hence its capacitance, will be measured relative to earth ground.
The following method is used to determine the value of a capacitance. Referring to FIG. 5, a controlled current source is configured to force charge into capacitor C x . The value of E x at time T=1 will be ##EQU1## where: E 0 is the initial voltage across capacitor at T=0; i(T) is the current as a function of time; and T is the time. Thus, if the forcing function and the initial charge level of the capacitor are known, the capacitance is inversely proportional to E x after time T or, conversely, proportional to the time necessary for the voltage to rise to a given E x .
The capacitance measurement technique found to be satisfactory in the context of the present invention is adapted in FIG. 3. The capacitance communicated through the lamp cord is effectively placed in parallel with the lumped capacitor C1, giving a total capacitance of C T (total capacitance of lamp and cord without being touched). The circuit 10 is a non-linear oscillator, specifically an astable multivibrator, whose operation will be discussed in a later section. The capacitance C T is charged for a forcing function created by the bi-stable output of the Schmidt trigger buffer through resistor R1. The voltage at point A will rise exponentially until the upper trigger level of the buffer is reached, at which time the buffer will change state. The capacitor C1 will then discharge exponentially until the lower trigger level is reached. Thus the period of the oscillator is proportional to C T . Essentially there is capacitance to frequency conversion, i.e., the higher the capacitance the lower the frequency.
ANALOG/DIGITAL EMBODIMENT
One preferred embodiment of the present invention which fulfills the design objectives and is commercially feasible is depicted in FIG. 4, and will be described in detail in the following sections. It is a hybrid analog/digital circuit.
As shown in FIG. 4, the lamp 10 is connected to the decoupling network 20. The decoupling network performs the functions of isolating the lamp cord from the power line at oscillator frequency; preventing 50/60 cycle power frequency from affecting the oscillator; preventing harmonics generated by the triac from affecting the oscillator; forcing the lamp cord to operate in common mode at oscillator frequency; establishing RF earth ground reference for capacitance measurement; and reducing triac "hash" radiation. The decoupling network 20 is connected to the oscillator 21.
The oscillator 21 is connected to the frequency to voltage converter 22 which generates a varying DC voltage whose average DC magnitude is a function of oscillator frequency. The higher the capacitance, the lower is the frequency of the oscillator 21 and the lower is the DC voltage generated by the frequency to voltage converter 22.
The bandpass filter 23, which is connected to the frequency to voltage converter 22, restricts the frequency response of the system to that range of frequencies which are generated by a valid touch, and rejects other frequencies which are treated as noise in the system.
The bandpass filter 23 is connected to amplifier 24 which raises the DC voltage output of the frequency to voltage converter 22 to a level concommitant with requirements of subsequent sections.
The amplifier 24 is connected to the threshold detector 25 which rejects all input signals below a certain predetermined minimum voltage level in order to prevent responses to invalid disturbances. The threshold detector 25 is connected to the timer 26 which functions to insure that the threshold detector output 25 is TRUE for a certain minimum length of time before a valid touch input will be recognized. It insures that a certain minimum time must elapse before a second valid touch input can be recognized. The effect is to "debounce" touch input, much like rapid sequential keyboard key depressions are "debounced" so that only the first key depression acts as a signal.
The timer 26 is connected to the phase controller 27. The phase controller 27 controls the triac conduction angle to provide three or more discrete power levels to the light bulb, plus OFF. The power level will advance one step in the repeating sequence OFF, LOW, INTERMEDIATE, HIGH, OFF each time a valid touch input is recognized.
DESCRIPTION OF OSCILLATOR
The oscillator 21 is adpated to provide touch sensitivity without radiating harmonic spectrum. It should be immune to ambient RF fields. Preferably oscillator 21 is an astable multivibrator based on a Schmidt trigger buffer, whose elementary form is shown in FIG. 3. As shown in FIG. 3, the frequency of oscillator 21 is inversely proportional to the time constant of R1 - C1, and the width of the hysteritic window VHY. The advantages of this configuration, in addition to the use of few components, are:
1. Low amplitude at point A. The maximum amplitude at this point (and thus the radiated power) is bounded by the hysteritic window which is about 1 volt at the chosen V DD of around 5.5 volts.
2. The waveform at point A is an exponentially increasing-decreasing function. This tends to reduce the harmonic spectrum relative to the square waveforms commonly encountered in digital circuits.
3. The impedance level at point A is quite low, since R1 has a value of typically 2k ohms. The ambient RF energy intercepted by the lamp cord is not of sufficient amplitude to significantly affect oscillator operation.
4. Inherent noise immunity of digital circuits. A linear oscillator is not used since it may operate as a linear amplifier and pass along spurious signals picked up by the lamp cord to the subsequent RF demodulator.
There are two major causes of oscillator disturbance. The first is synchronization of the oscillator to an external signal close to the natural frequency, i.e., the oscillator may phase lock if the amplitude of the external signal is high enough. The second is random jitter of the oscillator due to broadband ambient RF fields or occasional high energy pulses. The circuit of the present invention has been modified to provide stability when operating in an adverse environment. Typical sources of interference include: commercial broadcasting stations and amateur radio transmitters, automotive ignition systems, capacitor start electric motors, furnace igniters, and general switching transients. Extensive testing of this device has shown the probability of false activation by any of the above-mentioned interferences is extremely low in a consumer environment.
FIG. 7 shows the preferred oscillator circuit and FIG. 6 shows the circuit of FIG. 7 redrawn for analytical purposes. As shown in FIGS. 6 and 7, the basic frequency determining network consists of resistor 30 and the series string capacitor 31 and resistor 32. Capacitor 31, instead of being returned to ground directly as in the normal configuration, is grounded through resistor 32. This increases the operating frequency of the oscillator since point A can float on top of resistor 32, allowing the buffer to reach trigger level in less time. Thus the frequency is proportional to the impedance of the parallel network of resistor 32 and the reactances of inducance 33 (capacitor 34+capacitor 35) and C L (the effective impedance of the lamp and cord). The frequency of the oscillator will deviate around its centerpoint with variations C L . Inductance (choke) 33 and resistor 32 form a low pass filter to block stray high frequency energy; conversely choke 33 and C L form a low pass filter to attenuate oscillator harmonics at the lamp cord. Capacitor 34+capacitor 35 and resistor 32 form a high pass filter to block the 50/60 cycle power and triac hash from the oscillator.
An entirely different cause of oscillator disturbance is the high frequency impedance of the power line. This is a relatively complex phenomenon and will be explained in some detail. FIG. 13 is an analytical model showing all impedances affecting oscillator frequency. Component reference designators are the same as those in FIGS. 6 and 7. Exogenous impedances are also explicity designated, as follows:
CX1--capacitance between lamp structure and lamp cord;
CX2--capacitance between lamp structure and earth ground;
CX3--capacitance between power line earth ground conductor (in standard 3-wire system) and the neutral and hot conductors in common mode;
CX4--capacitance between operator and earth ground;
CX5--capacitive coupling to external noie source;
LX1--common mode self inductance between power line and earth ground;
RX1--common mode resistance between power line and earth ground.
To show how the power line impedance affects oscillator frequency, the model will be redrawn from the reference frame of the oscillator. Assume CX4=CX5=φ. From FIG. 14, it is evident that the power line impedance is part of the frequency determining network of the oscillator.
Ideally, the power line impedance to earth ground should be so low that it can be neglected. In residential or commercial wiring conforming to the standard electrical code a third wire, physically connected to earth ground, is present in the power cable along with the neutral and hot conductors. The common mode distributed capacitance between the line and ground conductors (CX3) constitutes a low reactance path to earth ground at operating frequency which simulates a hard earth ground. CX3 can be augmented by a physical capacitor (≅1000 pf) if necessary.
However, in many houses and other buildings the wiring does not have a grounded conductor in the power line, as in old or non-conforming wiring. In this case CX3/0, and the self inductance and ohmic resistance of the line becoming significant. Changes in impedance to earth ground caused by other loads being connected or disconnected from the power line can cause the oscillator frequency to shift. Also, two wire-line writing is more susceptible to external noise generators via CX5 (radio transmitters, etc.). Thus, the probability of false actuation is greater in the case of a two-wire line than in the case of a three-wire line.
To reduce the dependence of the oscillator on power line impedance and allow the device to operate without false actuation under non-ideal conditions requires careful consideration of the component values and operating frequency. The following guidelines apply:
The operating frequency should be above AM broadcast band, above common sources of RFI, and high enough such that CX1, CX2, CX3 and CX4 have relatively low reactance. However, the frequency should be low enough to be without the capability of a CMOS oscillator operating at 5 volts and low enough so that the inductive reactance of the power line is small compared to other impedances controlling oscillator frequency. The oscillator is designed so that its operating frequency is determined principally by CX2 and CX4, and is relatively insensitive to LX1 and CX3. The interface network is designed so that choke 45 and choke 46 (FIG. 7) are as low as practical (to shunt energy intercepted by the lamp cord). Chokes 45 and 46 have low distributed capacitance.
This oscillator circuit, when combined with subsequent circuitry, has been found to effectively meet the design objectives.
DESCRIPTION OF THE OTHER CIRCUITS
The interface network 20 (line coupling network) is shown in FIG. 7 and consists of triac 40, capacitors 41-44 and inductances (chokes 45,46). This network allows the 50/60 cycle power, as modified by the triac, to flow through the lamp cord to the lamp (load) without interfering with touch sense operation.
The chokes 45,46 decouple the load from the power line at operating oscillator frequency. This is necessary since the power line is a low impedance path to earth ground. The line cord and lamp are effectively "floating" and can easily be driven by the oscillator. The series capacitors 43,44 force the lamp cord conductors to operate in common mode at oscillator frequency, effectively as a single wire, and also serve as a balance connection point to the oscillator. The triac 40, triggered by the phase control circuitry, regulates the effective power delivered to the load. The capacitor 41 provides a low impedance path to the power line across the triac. Thus, the impedance to earth ground is fairly constant on this side of choke 45 regardless of the conducting state of the triac 40. If capacitor 41 were not present, substantial frequency modulation of the oscillator would occur when the triac is triggered. The capacitor 42 prevents triac hash from entering the power line.
The frequency to voltage converter 22 consists of a frequency divider and a phase-locked loop 51. Frequency division is provided by a frequency divider 50, shown in FIG. 7 (CE 4020B integrated circuit) or similar. Its frequency ratio is 16,384:1. The output frequency is about 200 cycles, which is a suitable operating range for the subsequent phase-locked loop. The divider 50 also averages out small random deviations in oscillator frequency.
Frequency demodulation of the oscillator is accomplished by an integrated phase-locked loop 51 (CD4046B integrated circuit) or similar. Phase-locked loop theory in general and the operation of this particular circuit is well documented. The phase-locked loop output is a signal whose average DC level is proportional to the frequency of the input signal, plus an AC component generated by the voltage controlled oscillator. The output is AC coupled by capacitor 51, since only frequency deviations, not absolute frequency, are of interest.
The amplifier 24 and bandpass filter 23 are combined and both functions are performed by a first operational amplifier ("op-amp") 52 which is configured as an inverting amplifier with a gain of about 40. The band width is about 2-16 cycles (3 db down). The low end cutoff eliminates response to slow changes due to power line variations and objects brought near the lamp. The high end cutoff eliminates response to frequency modulation due to triac triggering (120 cps pulse repetition rate), and the 200 cycle operating frequency of the voltage controlled oscillator in the phase-locked loop. A valid touch to the lamp produces an abrupt stepwide change in frequency, which is amplified with full gain by the band width provided. Thus, the gain stage provides a substantial improvement in the valid signal to spurious signal ratio.
The second op-amp 53 is configured as a voltage comparator which acts as the threshold detector 25. The threshold voltage, determined by the ratio of resistors 54 to 55, is set at a level commensurate with the required touch sensitivity, as determined by experimentation. Substantial hysteresis is provided around the comparator, by resistors 56 and 57, to eliminate jitter.
The timer 26 is provided by the R-C network resistor 58-capacitor capacitor 59 which represents a time constant of 33 milliseconds positive going and 200 milliseconds negative going. This cleans up and debounces the touch response in that the comparator must have a positive dwell of more than 30 ms to result in a valid touch response, and forces a separation of about 100 ms between successive responses. This R-C network also prevents response to short transients.
The output of the touch sense section, shown in FIG. 7, is a low to high logic transition at point B in response to a valid touch input. The relatively slow rise and fall times can squared up by a Schmidt trigger buffer if required. Each stage in the touch sense section, from the oscillator to the timer, is designed to reduce the probability of invalid response, while maintaining sufficient sensitivity to cope with the problems of real-world lamps, which are often varnished, enameled, heavily oxidized or rusty.
The triac phase control circuit 19 delivers three or more discrete power levels to the load, plus OFF, by varying the conduction angle of the triac in conventional fashion. This circuit will be discussed briefly. There are integrated circuits commercially available which perform this function.
As shown in FIG. 8, the triac phase control circuit 19 includes a zero crossing detector 70 (XNOR gate IC3-A-CD4077). A low to high transition occurs at zero crossing, which is integrated by RC network resistor 71 - capacitor 72, generating a logarithmic ramp at the inverting input of op-amp comparator 73. (IC1-D). The voltage at the non-inverting input of comparator 73 is determined by a digitally controlled voltage divider, consisting of ripple counter 74 (IC4A and B (DC 4013)) and gate 75 (IC3-C (CD 4077)). This voltage determines at what point on the ramp the comparator will kick negative, thus firing the triac via point D. Schmidt triggers 78 (IC2-A (CD 4093)) and IC2-B (CD 4093)) square up the input signal for application to the lock input of ripple counter 74. This circuit produces the sequence OFF-DIM-INTERMEDIATE-FULL-OFF.
PREVENTION OF FALSE ACTIVATION
In its intended use as a consumer product, frequent false activation would make this device essentially useless. There are three external causes of oscillator frequency deviation which could cause false activation: (1) RF fields; (2) power line voltage variations; and (3) power line impedance to earth ground variations.
The philosophy of the commercial embodiment is to make the oscillator as resistant to external disturbance as possible and, in addition, provide means to sense external disturbances and lock out the power level advance circuitry when they occur.
To effect line voltage glitch immunity, a combination of voltage regulation and logic circuitry is employed. As shown in FIG. 15, the voltage at point B is regulated to approximately 5.5 volts by an internal zener diode included in circuit 80 (IC3-CD4046). The voltage at point A is limited to 15 volts by zener diode 81 (Z2). As long as normal line voltage is present, zener diode 85 (Z1) will be in its reverse breakdown region and pin 5 of NAND gate 82 (IC1B-CD4093) will be high (about 4.5 volts). Thus the output of NAND gate 82 (IC1B) will be low, and consequently diode 83 (D1) will be reverse biased. When a power dropout occurs, the voltage at point A will immediately begin to drop as capacitor 84 (C11) discharges, and the voltage at pin 5, communicated through zener diode 85 (Z1) will drop accordingly. When the voltage at pin 5 reaches the lower trigger level (about 2.5 volts, the output of NAND gate 82 (IC1B) will go high. This forward biases diode 83 (D1) and pulls the inverting input of amplifier 86 (IC4A-1/2LM358) high. The amplifier output will thus be forced to ground, locking out the subsequent power level advance circuitry. Thus, touch control is locked out before a low voltage condition can change the oscillator frequency.
To effect RF field immunity, as shown in FIG. 15, NAND gate 87 (IC1D-1/4CD4093) is connected to the load side of decoupling chokes 88 (L2) and 89 (L3). When no RF interference exists, the output of this gate is high (normal condition). Differential RF voltage existing between the power line and the lamp cord of sufficient amplitude will drive this gate, configured as an inverting buffer, in synchronism. When the output of this gate goes low, it will cause the output of gate 82 (IC1B) to go high, thus inhibiting power level advance as previously detailed. Capacitor 90 (C2) and resistor 91 (R19) control the sensitivity, and hence the trip point, of the RF glitch inhibit system. Thus, touch control is locked out before an RF field can change the oscillator frequency.
One problem with the RF glitch lockout system is the RF field generated by the triac. The transient generated by the transition of the triac to the conducting state creates a burst of energy within the frequency spectrum to which the RF lockout will react. Thus, if the sensitivity of the RF sense circuit is made high enough to be useful, the device will lock itself out. This problem is solved by synchronizing the RF detent circuit with the firing of the triac. Network capacitor 92-resistor 93 (C3-R20) communicates positive going triac pulses to inverting buffer IC1C, whose output causes pin 9 of NAND gate 87 of IC1D (normally high) to go low whenver the triac fires. Pin 8 of NAND gate 87 IC1D (normally low) goes high when the triac fires. Therefore, the output of NAND gate 87 IC1D does not change state, making the circuit immune to triac generated energy.
The operating frequency of the oscillator is nominally 3 Mc, found empirically to have the greates immunity to ambient RF and power line frequency impedance variations. The frequency divider is a CD4020 type (14 stage) providing a division factor of 16,384. This provides a time delay of approximately 5 milliseconds, allowing the RF glitch lockout sufficient time to react, plus a high degree of oscillator frequency time averaging.
The circuit detailed herein is totally immune to false activation even in an adverse environment.
DIGITAL IMPLEMENTATION
This section deals with an all digital method and hardware to implement the entire device on one integrated circuit chip, except line interface and power supply components. All functions performed by the hybrid digital/analog circuitry described in the previous section are simulated in the all-digital version by soft ware routines.
The general approach is shown in FIG. 9. The touch sense oscillator 100 is identical to that in the hybrid version. Oscillator 100 is connected to a counter 101 which is enabled for a precisely controlled time interval. The value in the counter at the end of the time interval is proportional to oscillator frequency. The counter 101 is connected to a differentiator 102 since only changes in oscillator frequency are of interest. The differentiator 102 is connected to an integrator 103 which averages out residual 120 cps frequency modulation due to triac triggering and small random deviations. The integrator 103 is connected to the threshold comparator 104 which determines whether a frequency shift is large enough to be considered a valid touch input. The threshold comparator 104 is connected to the timer 105 which insures that the threshold comparator 104 is true for sufficient time before a valid touch input is indicated. A validated touch input advances the triac phase control 106 by one step. The power glitch inhibit 107 locks out touch control on power on and power dropouts until a re-equilibration period has passed.
The hardware shown in FIG. 10 is essentially a micro-controller executing a fixed supervisor routine. The touch sense oscillator 100 is asynchronous with the system clock. The ALU provides signed binary addition and subtraction, shifting, memory access and general micro-code execution. Two FIFO register stacks are implemented for moving average calculations. Power glitch detection sets a flag when disturbances in the line voltage occur.
The mainline routine, shown in FIG. 11, is executed every 25 milliseconds. Thus, the oscillator is sampled 40 times per second. Certain software functions are shown as subroutines for ease of presentation. The end result of the software is to signal the triac phase control 106 (on chip) to advance one power level if a valid touch has occurred. The subroutine `SAMPLE` counts the number of oscillator pulses in a one millisecond interval. The subroutine `DIFFERENTIATE` subtracts the present oscillator frequency from the average value over the last 32 samples, and thus responds only to abrupt changes. The subroutine `INTEGRATE` provides a moving average of the changes in oscillator frequency over the period 4 sample cycles to smooth out random variations. The output of `INTEGRATE` is compared to a fixed threshold value. If it is higher than the threshold for two consecutive sample cycles, the triac control circuit will be advanced one power level. The output of `INTEGRATE` must then be less than the threshold for two consecutive sample cycles (i.e. touch removed) before the triac control can be advanced again, thus implementing the timer function. A Power Glitch indication locks out touch response for 64 consecutive sample cycles.
SOFTWARE CONTROL FLOW
Normal Idling Loop--When idling in equilibrium, the control flow is 2-3-5-6-8. At step 11, the integrator output (M5), which would be zero, will test less than the threshold, and the control flow will continue 12-4-2. Thus, the oscillator frequency is being continuously tested. If the oscillator does shift frequency, but not enough to trip the threshold (or in the wrong direction) the above routine would still be followed.
Touch Sensed--The control flow will be 2-3-5-6-8 as above, but at step 11 M5 will test greater or equal and fall through to 16. At 16, OK-SIGNAL-FLAG (1 bit indicator, will test false, be set TRUE at 15, and control will jump back to 2. If, on the next cycle, M5 is still greater than the threshold, control will pass to 17, and the triac control circuit will be advanced one power level. Thus, we see that two consecutive cycles must occur with M5 greater or equal to the threshold, as required. After the triac control is signaled, LT-COUNT (4 bits, used to tally the number of times M5 is less than the threshold) is set to zero, Ok-SIGNAL-FLAG is set off at 4, and control passes back to 2.
Second Touch Sense--Two cycles must elapse with M5 less than the threshold (touch removed) before the triac control can be signaled again. Since LT-COUNT is set to zero after the triac control is signaled, M5 must test less at step 11 twice before step 13 will pass control to the triac routine.
Power Glitch Routne--When the line voltage level changes abruptly, the power glitch flag will go on. This occurs on power-up, power dropout, or power surge. This routine locks out touch sensing until the unit has time to re-equilibrate. If the power flag tests TRUE at step 8, the software enters a loop which causes 64 sample cycles to go by before touch sense is re-enabled.
Subroutine `SAMPLE`--Takes 1 millisecond samples of the oscillator frequency. Since the frequency is about 2.5 Mc, the samples will be about 2500 10 , requiring a 12 bit counter.
Subroutine `DIFFERENTIATE`--Subtracts the latest sample from a moving average of the last 32 samples. Thus, if the oscillator frequency is decreasing, the output will be positive. A FIFO register stack is used to maintain the moving storage.
Subroutine `INTEGRATE`--Maintains a moving average of the last 4 numbers passed from the `DIFFERENTIATE` routine. Smoothes out random variations.
ANALOG/DIGITAL PRACTICAL EMBODIMENT
FIG. 15 details one suggested preferred embodiment of a tested and commercial analog/digital embodiment which employs commercially available components. | A small electronic module to regulate the power delivered to a lamp or similar appliance is plugged into the household electrical outlet and the lamp to be controlled is, in turn, plugged into the module. Each time the lamp is touched the power to the bulb increases by one step, typically in the sequence OFF, DIM, INTERMEDIATE, FULL, OFF. The module device operates by sensing the capacitance change when the lamp is touched and communication between the lamp and the device occurs through the lamp cord. | 8 |
BACKGROUND OF THE INVENTION
The subject invention relates to the field of document generation systems, and more particularly to a method and apparatus for interacting with a periodically issued document, like a newspaper, to revise the document content to be more customized to an individual subscriber.
The invention is particularly applicable to printed documents which include dataglyphs or tokens representative of the document and the subscriber to the document, wherein subscriber redactions to the document itself can be identified for modifying content and form of future editions. However, the subject invention is applicable to any system which provides routine generation of a document edition, either printed or electronically, and that presents an opportunity for the customized editing of a second edition by general profile guidelines for communicating information indicated by the subscriber as being particularly useful or of interest.
For purposes of pure reading, it is a fact people vastly prefer paper documents as opposed to electronic displays. However, most newspaper or news magazine type documents present an overwhelming variety and amount of information, most of which is of no interest to any one particular subscriber. For example, the top ten news stories in the paper may be of interest to most readers, but beyond these, the remaining content will have variable interest to any one reader depending upon the reader's hobbies and occupation.
Given the wealth of information available today, custom filters which adjust content to a particular user's desires are becoming increasingly useful. In electronic communication, profiles for filtering E-mail and Usenet articles are very common. On the other hand, mass media has traditionally been organized on a much coarser granularity, as by subject matter such as “sports” or “business”. For the web, a number of mass media publications, e.g., newspapers and magazines, have offered on-line information services which include intelligent filtering based on user profiles. However, given the affordance of paper and the way people prefer to read print media, these online services cannot be widely used for fine-grained profile adjustments, i.e., customizing the content to individual subscribers, as long as they read on paper rather than online. The evidence remains strong that users will continue to prefer reading on paper as opposed to reading with an on-line browser. This complicates the updating of fine-grained subscriber profiles. Users need to remember what they thought of authors or topics between the time they read articles and the particular time they next use their computer.
Downloading and printing of electronic forms of newspapers from the web provides the convenience of paper for reading, but precludes filtering of content except to the extent that the reader wishes to spend the time selecting and printing portions of a single document. More importantly, this printing precludes back-channel communication to the publisher in a manner to identify a profile of preferences of the subscriber. In other words, if the subscriber wished to identify subjects having a high interest and subjects having a low interest, a publisher could print available content according to these preferences to provide a somewhat customized document. The profile thus comprises the recorded set of preferences and dislikes.
The present invention contemplates a new and improved system which overcomes the prolix disadvantages of mass media print communication to effectively combine the advantageous features of the two relevant technologies. That is, the customized newspaper which can now be read on an electronic display, is combined with the affordances and conveniences of a printed paper interface, for a resulting interactive newspaper, customized to a subscriber-identified profile.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a system of profile guided printing of a paper document, including facilitating channel interaction from a reader for contemporaneous upgrading of the profile based upon a detected user response to document content. The system comprises generating an initial document content corresponding to a present reader profile. The content is printed as a paper document, together with a token or tokens. The reader redacts the paper document, typically with pre-selected indicia, to represent desired changes in future editions of the document. The document is scanned in a scanning device to identify the reader and the desired changes indicated by the reader's marking. The scanning system uses the token that identifies the document to look up an online copy of the document. So the system will know exactly what the document and its pages looked like. The scanner knows the location of the indicia it just scanned, and by comparing with the online copy, it knows exactly where the indicia lies relative to the articles on the page. In one embodiment, a token is physically associated with an indicia but the tokens can be placed anywhere. The present reader profile is adjusted in accordance with the scanning so that the next paper document that is printed corresponds to an upgraded reader profile. The system continually operates over time and sequential editions to continue to provide fine grained adjusting of the reader profile.
The tokens preferably comprise dataglyphs having a minimal effect on the efficient presentation and appearance of the document.
In accordance with another aspect of the present invention, an interactive newspaper is provided which includes news content and tokens representative of an identity of the newspaper and the news content therein, wherein specially marked regions are disposed for being modified by a reader and thereafter read by a scanner, essentially comprising a smart recycling bin, for selective adjustment of the news content of a subsequent edition of the newspaper. The special regions are individually associated with a particular item of news content wherein the reader modification is indicative of either deletion or addition of news content having similar subject matter in a subsequent edition. There may or may not also be a token associated with each special region.
In accordance with another aspect of the present invention, a smart wand is used to detect the document and contents and can be controlled by the user to indicate desired change to the contents. The wand can be used to scan dataglyphs or tokens, usually physically associated with each content item. Control switches on the wand can be used to indicate either deletion, lessening, or expanding of the subject matter identified by the token. Stored information in the wand can be downloaded with any of several conventional means so that the user profile can be updated and the next document would be generated in accordance with the desired changes stored in the wand.
One benefit obtained by use of the present invention is a customizable push system for a mass media document so that readers can adjust by general subject matter what content is presented in subsequent editions of the document.
Another benefit obtained from the subject invention is the provision of a document which is customized to a reader, and thereby comprises a much more efficient presentation, paper consumption and time investment to a reader in ultimately reviewing the document.
A further benefit of the subject invention is back channel communication from a class of readers to a publisher on the relative interest of a plurality of selected items in the document or a response to explicit questions for the reader, whereby the publisher can have an appreciation of reader interest in different articles and responses to specific questions.
Yet another benefit of the present invention is a convenient vehicle for the subscriber to solicit more detailed or expanded information on a subject only first generally identified by the publisher.
Other benefits and advantages for the subject new interactive document system will become apparent to those skilled in the art upon a reading and understanding of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and steps and arrangements of parts and steps, the preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 is a fanciful diagram of a document including both content and tokens for identifying the document, the subscriber and the content;
FIG. 2 is a flow-chart/block diagram detailing the distinct elements of the system and steps practiced in accordance with the present invention;
FIG. 3 comprises an alternative fanciful illustration similar to FIG. 1 including more detailed instructive portions for communicating the desired changes to the document;
FIG. 4 is a flow-chart/block diagram of an alternative embodiment of the invention wherein a specialized wand is used in practicing the steps of scanning document tokens and user instructions for desired changes; and
FIG. 5 is a light pen/wand that could be used in accordance with the method of the invention illustrated in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein the showings are for purposes of illustrating the preferred embodiments of the invention only, and not for purposes of limiting the invention, the FIGURES show a document 10 in a format for facilitating back channel indication of a reader's preferences or dislikes concerning the document to a publisher, so that future editions can be more particularly customized for the subscriber. The invention thus provides an interactive media document which allows essentially a continuous updating of subject matter or form for a fine-grain profile of a reader/subscriber, particularly useful for print media documents.
With particular reference to FIG. 1, the document 10 is illustrated as a newspaper, including assorted content items 12 , 14 , 16 with associated tokens 18 , 20 , 22 , 24 . The tokens are preferably dataglyphs which allow preselected identifying data that can be encoded in a condensed form on a printed page in a reasonably aesthetic way. Although a plurality of tokens are shown, merely one token per page may be able to communicate all the necessary information. Keeping in mind that a newspaper is traditionally a one-directional media, i.e., it is read and discarded, the subject invention enables a narrow channel of return communication via the tokens. Token 18 is illustrated to comprise an identification of the subscriber of the document and the edition. Tokens 20 , 22 , 24 are associated with the articles 12 , 14 , 16 , respectively. The reader can thus mark an article associated with or adjacent to the token in a manner which can be appreciated upon return to the publisher as expressing a reaction to the article. For example, token 18 would identify that the particular document was intended for an individual subscriber, and would identify the edition that the subscriber was reading. If the subscriber was particularly interested in the subject matter of the article 16 , so that in a subsequent edition he would like addition or amplification of the news content of the article, the article itself or some marking box associated with this token 24 could be marked in a manner, such as a check mark, which could be read by a scanner to indicate that in the next edition of the newspaper, that subject matter should be expanded. Alternatively, if the subject matter of article 14 was a subject for which the reader has no interest, and would like to be deleted from future editions, the article or box can be marked with a different indicia, an “X”, so that the publisher would appreciate to delete such subject matter in the next editions. Providing a system where a reader can directly mark on the paper they are reading facilitates a wide variety of different indicia and tokens that can be implemented to communicate between the reader and the publisher. For example, several tokens could be associated with a particular article, merely comprising an abstract, wherein a check on the “full article” box would indicate that in the next edition a full text from the abstract would be provided. Alternatively, a token box would indicate a “loved” next to a movie in the paper's review section to include a vote in a readers' opinion poll. Many other forms of comments or responses are considered to be within the scope of the type of redaction a reader could exercise while reviewing the document 10 .
With particular reference to FIG. 2, a method for implementing the subject invention is illustrated.
The first step of generating the document is, of course, generating content for publication. The content could comprise a plurality of articles of news or features typically printed in a newspaper or magazine and stored in an article storage 30 . A profile storage 32 holds a plurality of individual subscriber profiles which are indicative of article subject matter and subscriber features preferred by the individual subscriber. Both of the content storage 30 and the profile storage 32 are, of course, intended to be continually revised and updated. It should be kept in mind that the profile does not exactly specify what content is to be selected from the article storage, but rather is merely an indication of preferences and dislikes which, when compared with available content by the selector 34 , essentially provides a profile guided formatting of a data stream which will ultimately comprise the document format. Specifically, the profile may merely comprise a probability or preference value which can prioritize all of the available content into a preferential order of composition as the ultimate content in the document format.
The selector 34 receives the subscriber profile and selects the subscriber features and a portion of the plurality of articles from the article storage 30 in response to the particular subscriber profile. The selector communicates a list of the articles, comprising references, features, services and programs to the token generator 36 , which determines which of these items is to be associated with the token in the document format. As noted above, the tokens preferably comprise dataglyphs which necessarily identify the identity of the document, including its edition, the subscriber and the particular items with which the tokens are associated. The document content selector 34 is also directly communicated to the combiner, encoder layout engine 38 , which combines the subscriber features and selected portion of the content into a document format including the embedded tokens disposed for indication of the subscriber redactions. The format will thus coincide and be printed by printer 40 in a form such as illustrated in FIG. 1 . The printed document 42 is thus read and redacted at step 44 .
If the reader determines that no responses are desired upon finishing the reading, the document can merely be discarded.
Alternatively, if communication is desired with the publisher then the document can be disposed into a recycling bin and provided to a scanner 46 which will recognize the dataglyphs to identify the document, the edition, the subscriber and those redactions placed on the document by the reader. The scanning information is communicated to a segmenter, token decoder 48 , which determines the dataglyphs and redactions and translates them into a form which can be communicated as meaningful information to a publisher including an update of the subscriber's profile 50 for adjusting the subscriber's profile in the profile storage 32 .
The method facilitates back channel interaction from the reader for contemporaneous upgrading of the reader's profile in response to a review of the document content. It is intended that the form of communication must be as easy and convenient as possible for the reader and may simply comprise pen markings on the document in preselected manners, preferably cited in the document itself.
In actual implementation, the system comprises a printing operation at a popular location, such as a commuter station, where both the printer 40 and recycling bin 46 can be conveniently located. The printing operation itself is not envisioned to take very long, since the document is intended to be customized for efficiency in terms of relative subject matter for each individual subscriber.
To this point, the invention has been referred to as a newspaper and in terms of content being produced by a mass media publication. The invention has equal merit within an organization where the publication is more of a newsletter than a newspaper. In this context, the delivery would most likely be via mail boxes and the content would be more specific to that organization. As an example, a customized newsletter may contain content such as updates from information services, internal distribution lists, or menus from the cafeteria. In this context even more personalized data might be presented. An employee who had not turned in their W 2 tax form might get a reminder at the end of the newsletter and this reminder would continue to appear in future issues until the form is submitted.
From a technical standpoint, this idea does not require any complex innovations for the document itself. Very little data needs to be encoded on each page, i.e., the user I.D., the edition number, page number and some information about the geometry and resulting action of the feedback areas. This can likely be represented in a few hundred bytes, well within the capacity of dataglyph regions with an area of three or four square inches. Both the decoding of the glyphs and recognition of marks on paper have been included in existing Xerox® products and do not represent a hurdle. A printing/scanning/ decoding system could be bolted onto an existing customized media application to create a workable system.
With particular reference to FIG. 3 an alternative embodiment 10 of a more user instructive document is shown in which several articles 52 , 54 , 56 , 58 are each associated with appropriate tokens 60 , 62 , 64 , 66 , respectively, but also are each provided with dedicated questionnaire boxes prompting specific responses from the user (as noted above, one token per page could accomplish the same purposes as the plurality shown). More specifically, with regard to the article 52 , the user has selected the “more” box 68 with a check mark so that the subject matter of article 52 will be identified as a subject matter for this particular user's profile for which more information can be provided in the next published edition. Similarly, with regard to box 58 , the user indicated that he/she wants more detailed information concerning weather reports.
With regard to document portion 56 , concerning “IRS Penalties”, the user indicated that “less” information is desired. Lastly, with respect to article 54 relating to real estate, the “x” through the whole article with a pen mark indicates that the entire subject matter of this document portion, e.g., real estate, can be deleted from the next edition and the user's profile will put a lowest priority on any reports for this subject matter.
With particular reference to FIG. 4, another alternative embodiment is shown in which a document generation is identical to the embodiment of FIG. 2, (like numerals identify like steps) but in this embodiment rather than employing a scanner 46 for scanning the redacted document, the user employs a smart wand (FIG. 5) for identifying desired changes in the document, at the same time as when reading the document itself. More particularly, FIG. 5 shows a smart wand 70 having control switches 72 , 74 , 76 . The wand 70 is capable of reading and storing dataglyph information 20 , 22 , 24 and so when reading a particular article, the switches in the wand 72 , 74 , 76 can be used to either indicate if the subject matter of the article should either be deleted, lessened, or expanded in the next published edition. A light 78 or other indicator (e.g., sound) will confirm the complete reading of a token by the wand. As seen in the flow-chart of FIG. 4, at step 80 , the user while reading the document can position the wand over an associated token to a particular article, wait for token identification confirmation and then control the wand to indicate preferences by operating the control switches 72 , 74 , 76 . At step 82 , the data stored in the wand indicating the user's desired changes to the document can be downloaded over a network to a system. Conventional downloading schemes are known, such as an infrared reading link, or perhaps a docking system for the pen for direct link communication to a control system. After the system has received the downloaded information, the user's profile is updated, step 50 , and stored as a guide in the generation of the next published document.
A feature of the embodiment of FIG. 4 is that it is not necessarily limited to easily scanned documents and can be used with any types of display since the redacted document itself is not necessary for scanning identification of the information representative of desired changes to the documents. Reading wands can simply scan many things (e.g., cereal boxes, wall posters, etc.) that are not practical to put into an ordinary scanner. Since the information is stored in the reading device 70 , the particular form or subsequent use of the document becomes irrelevant to the updating of the user profile. To this end, alternative means for identifying and recording user information representative of desired changes, particularly for electronic display information, could comprise touch screens, light pens or the like for electronic displays, but it is the intention of the invention to be primarily directed to what appears to remain most users' preference for paper published formats.
The invention has been described with reference to a preferred embodiment. Obviously modifications and alterations will occur to others upon the reading and understanding of the specification. It is our intention to include all such modifications and alterations insofar as they come within the scope or the appended claims or the equivalents thereof. | A method and apparatus of profile guided printing of a paper document facilitates back channel interaction from a reader for contemporaneous upgrading of the profile in response to document content. The document is printed to include tokens representative of the reader and its content. While being read, the document is redacted by the subscriber in a predetermined manner representing desired changes in the document, or responses to publisher inquiries. The document can be scanned in a smart recycling bin to identify the reader and the desired changes. The reader profile is adjusted by the publisher into an upgraded reader profile upon identification of the reader redactions. Alternatively, a smart wand is used to detect the document and contents and is controlled by the user to indicate changes to the contents. The wand can store the user's and document's identification, and the desired changes and can be downloaded for updating the profile. The next document generated corresponds to the upgraded profile. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
This is a continuation application of U.S. patent application Ser. No. 12/159,537 filed in the USPTO on 27 Jun. 2008, which is the US National Phase of PCT Application No. GB2007/00232 filed 24 Jan. 2007, which claims priority to British Patent Application No. 0601390.8 filed 24 Jan. 2006.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable
REFERENCE TO A SEQUENCE LISTING
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus for playing a game. In particular, it relates to a two player game in which the players play against each other.
2. Description of Related Art
A known game apparatus is disclosed in EP 0827763. This describes a game board in which a ball is used to knock over pins in a ten pin bowling game. This game apparatus has the disadvantage that only one player can use the game apparatus at any one time. Whilst more than one player can play indirectly against each other by recording scores, two players cannot play simultaneously. This may reduce the interest of the game.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a game apparatus. Thus, two players can play simultaneously, increasing the excitement and interest of the game.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described, by reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a first embodiment of the game apparatus of the present invention;
FIG. 2 is a cut away side elevation of a first embodiment of the apparatus;
FIG. 3 is a cut away side elevation view of a first embodiment of the application;
FIG. 4 is an exploded perspective view of a first embodiment of part of the apparatus of FIG. 1 ;
FIG. 5 is a perspective view of part of a first embodiment of the apparatus of FIG. 4 ;
FIG. 6 is a perspective view of a part of a first embodiment of the apparatus of FIG. 1 ;
FIG. 7 is a perspective view of a second embodiment of the present invention; and
FIG. 8 is a side elevation view of part of the apparatus of the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows game apparatus 1 , which is intended for use by a first player and a second player playing a game against each other. The apparatus 1 comprises a rectangular playing surface 2 mounted in a housing 4 . The housing 4 provides side walls 6 extending along the long edges of playing surface 2 . Two flippers 8 are located at each of the short edges of the playing surface 2 . Each flipper 8 is controlled by a button 10 .
A first set of playing pieces 12 are arranged over a first area 14 of the playing surface 2 . A second set of pieces 16 are arranged over a second area 17 of the playing surface 2 . The playing pieces 12 , 16 are supported by a transparent substrate 18 spaced above the underlying playing surface 2 .
A projectile, in the form of a spherical ball 24 in play is fired across the playing surface 2 by the flippers 8 . A deflector 34 is located between each pair of flippers 8 . The deflector 34 is triangular in shape, in order to deflect the ball 24 onto a flipper 8 .
Each flipper 8 is an arm rotatable about one end substantially in the plane of the playing surface. Actuation of each button 10 causes an associated flipper 8 to rotate. Each flipper 8 will be spring-biased by spring means (not shown) to a rest position, from which it can be rotated by depression of a button 10 .
The spring means is arranged such that a small depression and release of the button 10 will result in a small retraction and rotation forwardly, and thus a small force on the ball 24 .
The spring means is associated with a release means (not shown). The spring means and release means are arranged such that after a large depression of the button 10 , the release means will cause the spring means to automatically release and activate the flipper 8 . This provides for a large force on the ball 24 . The player thus has only to apply a relatively strong force inwardly on the button 10 , and at a predetermined point the flipper 8 will automatically be released to rotate and apply a force on the ball 24 . The sudden release of the flipper 8 increases the initial speed of rotation of the flipper 8 , allowing a greater force to be applied to the ball 24 than obtainable by merely removing pressure from the button 10 to release the flipper 8 .
Each flipper 8 has a forward surface which contacts the ball 24 . The forward surface has a concave profile, defining a very shallow U-shape. This arcuate shape allows the player to control the direction in which the ball 24 travels from the flipper 8 , by varying the position of the ball 24 on the flipper 8 when the flipper 8 is rotated.
With reference to FIG. 2 , the substrate is a rigid laminar sheet 18 . The substrate 18 is supported by the housing 4 in a horizontal plane. A plurality of circular holes 36 are formed in the substrate 18 , for holding the playing pieces 12 , 16 in position. The playing pieces 12 , 16 each have an upper portion 20 , which in use is located above the substrate 18 , and a lower peg portion 22 which extends below the substrate 18 . The substrate 18 supports the playing pieces 12 , 16 over the playing surface 2 such that the bottoms of the lower peg portions 22 are spaced from the playing surface 2 by a distance greater than the height of the ball 24 .
The playing surface 2 is shaped to affect movement of the ball 24 . The first area 14 of playing surface 2 is formed by a first ramp 26 and the second area 16 by a second ramp 28 . Ramps 26 , 28 are inclined with respect to the horizontal, and meet at an apex 30 , which is the highest point of the playing surface 2 .
FIG. 4 shows the housing 4 is preferably formed in two pieces, and connected together by connectors 32 . The substrate 18 is also formed in two pieces. This allows the apparatus 1 to be stored in a compact form.
FIG. 5 shows part of the substrate 18 in the second area 17 . Holes 36 are arranged in four rows, each row being parallel to a short side of the playing surface 2 .
FIG. 6 shows a playing piece 12 . The upper portion 20 is in the form of a planar, rectangular sheet with a depiction of a character. The lower portion 22 is a peg, as previously described. A circular flange 38 extends radially outwardly between the upper portion 20 and lower portion 22 . The flange 38 has a diameter which is greater than the diameter of the holes 36 , so that the flange 38 supports the playing piece 12 on an upper surface of the substrate 18 while the peg 22 extends through a hole 36 to below the substrate 18 .
In use, the game apparatus is initially set up by placing the playing pieces 12 of the first set in the holes 36 located above the first area 14 . The second set of playing pieces 16 are inserted into the holes 36 located above the second area 17 . The first player locates the ball 24 on the playing surface 2 adjacent a flipper 8 at the first end 14 . The first player then operates the flipper 8 by pushing the button 10 . The flipper 8 rotates and propels the ball 24 , at high speed along the playing surface 2 and up ramp 26 . When the ball 24 passes the apex 30 , the speed of the ball 24 means that it continues upwardly and so leaves the playing surface 2 . If the first player is successful, the ball 24 strikes a peg 22 of a playing piece 16 . The impact of the ball 24 urges the playing piece 16 upwardly out of the hole 36 , causing it to lie horizontally on top of the substrate 18 .
With reference to FIG. 3 , an impact area 42 is shown for the playing pieces 16 of the second player when the first player is in control of the ball 24 . The pegs 22 of the playing pieces 16 of the second player in this area 42 may be hit by the ball 24 after it flies off the ramp 26 . A safe area 40 for the playing pieces 12 of the first player is shown. The lower portions 22 of the playing pieces 12 in this area 42 will not be hit by the ball 24 , since the ball 24 will safely pass underneath them. The ramps 26 , 28 therefore provide a means for the ball to strike the playing pieces of the opponent player, and not strike the playing pieces of the player who is controlling the ball. The danger area 40 and safe area 42 clearly reverse sides when the second player has a turn.
If the first player is unsuccessful, the ball 24 will return to the playing surface 2 without knocking a playing piece 16 from its hole.
Whether successful or unsuccessful, the ball 24 will then roll to adjacent a flipper 8 at the second side 17 , controlled by the second player. The second player can then actuate the flipper 8 by pushing the associated button 10 , and attempt to knock out a playing piece 12 of the first player in the same manner as described above.
The winner of the game is the first player to knock all of his or her opponent's playing pieces out of their holes.
A second embodiment of the present invention is shown in FIG. 7 . The apparatus 101 is intended for use by a first player and a second player playing a game against each other. The apparatus 101 can be used to play a “Battleships” type game, in which the players attempt to find their opponent's ships by guessing squares. The apparatus 101 allows conventional game play, and additionally provides apparatus to “destroy” an opponent's ships.
The apparatus 101 comprises a rectangular playing surface 102 mounted in a housing 104 . The housing 104 provides side walls 106 extending along the long edges of playing surface 102 .
A first set of playing pieces 112 are arranged over a first area of the playing surface 102 . Alternatively, a second set of pieces (not shown) are arranged over a second area of the playing surface 102 . The playing pieces 112 are supported by a substantially opaque substrate 118 spaced above the underlying playing surface 102 .
The substrate is a rigid laminar sheet 118 . The substrate 118 is supported by the housing 104 in a horizontal plane. A plurality of circular holes 136 are formed in the substrate 118 , for holding the playing pieces 112 , 116 in position. Holes 136 are arranged in a grid.
A projectile, in the form of a spherical ball (not shown) in play is fired across the playing surface 102 by a ball firing means (not shown).
The playing surface 102 is shaped to affect movement of the ball. The first area of playing surface 102 is formed by a ramp (not shown) and the second area 116 by a second ramp (not shown). Ramps are inclined with respect to the horizontal, to define a trough, the meeting line between the ramps being the lowest point of the playing surface 102 .
The apparatus 101 comprises two viewing devices 140 , one located at each of the short edges of the playing surface 102 . The viewing device 140 resembles an upside-down periscope. The viewing device 140 has a viewing aperture or screen 142 above the level of the substrate 118 , configured to allow a player to look into the viewing device. The viewing device 140 has a target aperture or screen (not shown) located between the level of the substrate 118 and the playing surface. The viewing device 140 comprises mirrors and/or prisms (not shown) providing an optical path between the viewing aperture and the target aperture.
The viewing device 140 is rotatable about a vertical axis, such that a player can rotate the viewing device by gripping handles 150 . The viewing device 140 is arranged such that a player looking into the higher part of the device 140 , at the viewing aperture, is able to see beneath the substrate 118 .
A ball firing means is attached to each of the viewing devices 140 . Each ball firing means is adapted to receive a ball, and eject the ball in a direction chosen by a player. The operation of each ball firing means is controlled by a button. The ball firing means is rotatable about a vertical axis as the viewing device 140 is rotated.
The viewing device 140 is provided with sights (not shown). The sights provide a visual indication of the direction of travel of a ball fired by the ball firing means.
The apparatus 1 comprises two pairs of marker boards 160 , 162 . The boards 160 , 162 are provided with a grid having plurality of blind bores 164 . Each board 160 , 162 has rows labeled 1 to 10 , and columns labeled A to J.
A marker 166 can be placed in a bore 164 in order to assist with game play. Markers are provided in two colors, one color, for example red, to mark a “hit” and one color, for example white, to mark a “miss”.
FIG. 8 shows a playing piece 112 . Each piece 112 has an upper portion 120 which in use is located above the substrate 118 , and a lower peg portion 122 which extends below the substrate 118 . The upper portion 120 is in the form of a ship. The substrate 118 supports the playing pieces 112 , 116 over the playing surface 102 such that the bottoms of the lower peg portions 122 are spaced from the playing surface 2 by a distance less than the height of the ball 124 . The lower portion 22 is a circular peg, as previously described, with a diameter less than the diameter of the holes 137 .
The housing 104 may form part of the packaging of the apparatus 101 , such that a reduced amount of additional packaging is required.
In use, the game apparatus is set up with none of the playing pieces 112 , 116 on the substrate 118 . The first and second players play the known game of battleships on boards 160 , 162 .
The first player attempts to guess the location of a ship of the second player. The first player does this by stating their guess that a ship is at a particular position, identified by the column and row identifiers. If the first player guesses successfully, the second player must declare that there has been a “hit”. Since the ships preferably cover two or more bores 164 , the ship as a whole is not immediately ‘found’. If the first player's guess does not coincide with a ship, the second player declares there has been a ‘miss’. The second player then guesses the location of a ship of the first player, and play repeats.
Once a player has successfully achieve a ‘hit’ on all of the hole positions which a single ship occupies, that ship is considered to be ‘found’. The player who found the ship scores 20 points, and the opportunity to ‘destroy’ the ship. An equivalent ship is placed on the substrate, with its pegs extending through a hole 136 . The ship is ‘destroyed’ by means of the viewing device 140 and ball firing means. The player looks through the viewing device 140 to view the playing surface 102 . The player rotates the viewing device 140 to line up the peg 122 of the ship with the sights. Once the peg is lined up with the sights, the player fires a ball from the ball firing means towards the peg. If the ball successfully strikes the peg, the peg will be forced upwardly and cause the playing pieces to be urged out of the hole. The playing piece 112 will then lie entirely above the substrate 118 , and the ship considered to be ‘destroyed’. The player will receive 20 points for destroying the ship.
If the player was not successful with their first shot, the player may take another shot. The player may be allowed up to five shots to destroy the ship. If none of the shots are successful, then the player is awarded no points and the play continues.
Once all of the ships have been wholly located, all of a set of pieces 112 , 116 may be placed on the substrate 118 and the player provided with five balls to dislodge as many pieces as possible from the substrate 118 . The winner of the game is the player with the most number of points once all the ships have been identified.
The substrate 118 has been described as opaque. Alternately, the substrate 118 may be transparent, or may be semi-opaque. In particular, the substrate 118 may be ‘frosted’ to allow a player to have a distorted or incomplete view of the surface below the substrate. | An apparatus for playing a game comprising a playing surface having a first area and a second area, a projectile, and at least two propulsion devices. First and second sets of playing pieces are provided, each playing piece having a lower peg portion, and a substrate overlaying and spaced above the playing surface and extending across both the first and second areas of the playing surface. In a game, the playing pieces are located on the substrate above the first area of the playing surface, with their peg portions extending below the substrate, and each propulsion device is capable of propelling the projectile such that the projectile can impact with a peg portion of a playing piece and thereby dislodge the playing piece. | 0 |
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to an image forming apparatus equipped with a developer charging member for charging the developer remaining on an image bearing member, and is suitable for a cleaner-less image forming apparatus, that is, an image forming apparatus which does not have a dedicated cleaner. In particular, it relates to a cleaner-less image forming apparatus, in which the developer (toner) remaining on an image bearing member after the image transfer process is removed (recovered) from the image bearing member by the developing apparatus so that the recovered developer can be reused.
Heretofore, an electrophotographic image forming apparatus of a transfer type, such as a copying machine a printer, a facsimile, etc., comprises: a photoconductive member as an image bearing member which usually is in the form of a drum; a charging apparatus (charging process) for uniformly charging the photoconductive drum to predetermined polarity and potential level; an exposing apparatus (exposing process) as an information writing means for forming an electrostatic latent image on the charged photoconductive member; a developing apparatus (developing process) for visualizing the electrostatic latent image formed on the photoconductive member with the use of toner as developer; a transferring apparatus (transferring process) for transferring the toner image from the surface of the photoconductive drum onto transfer medium, for example, a piece of paper; a cleaning apparatus (cleaning process) for cleaning the surface of the photoconductive drum by removing the toner remaining, by a certain amount, on the surface of the photoconductive drum; a fixing apparatus (fixing process) for fixing the toner image on the transfer medium; and so forth. The photoconductive member is repeatedly subjected to an electrophotographic processes (charging, exposing, developing, transferring, and cleaning processes) to form images.
The toner remaining on the photoconductive drum after the transferring process is removed from the surface of the photoconductive drum by the cleaning apparatus, and collected as waste toner in the cleaning apparatus. From the standpoint of environmental preservation, effective utilization of natural resources, and so on, it is desired that waste toner such as the above described one is not generated.
Thus, there has been developed an image forming apparatus in which the untransferred residual toner, or the so-called waste toner collected in the cleaning apparatus, is returned to the developing apparatus to be reused.
There has also been developed a cleaner-less image forming apparatus which does not have a dedicated cleaning apparatus, and in which the untransferred residual toner, or the toner remaining on the photoconductive drum after the transferring process, is removed from the photoconductive drum by the developing apparatus to be reused, at the same time as an electrostatic latent image on the photoconductive drum is developed by the developing apparatus (developing/cleaning process).
The elimination of the dedicated cleaning system makes it possible to reduce image forming apparatus size and simplify an Image forming apparatus. Further, the lack of a dedicated cleaning member means that there is no rubbing of the surface of the photoconductive drum by the cleaning member, lengthening the service life of the photoconductive drum. In other words, the elimination of the dedicated cleaning system offers substantial merits.
The developing/cleaning process is a process in which the toner remaining on the photoconductive drum after the image transfer is recovered by the developing apparatus during the following developing process. More specifically, after the image transfer, the area of the photoconductive drum, from which the toner image has been transferred, is charged, and then, is exposed to form an electrostatic latent image thereon. Then, the untransferred residual toner on the portions of the peripheral surface of the photoconductive member (non-image portions), to which toner is not to be adhered, is recovered into the developing apparatus, by the fog prevention bias (difference Vback in potential level between DC voltage applied to developing apparatus, and the surface potential level of photoconductive drum. According to this method, the untransferred residual toner is recovered into the developing apparatus and is reused for developing electrostatic latent image in the following image formation cycles. In other words, no toner is wasted.
Therefore, a user does not need to be bothered by the waste toner.
Further, having no dedicated cleaner is advantageous from the standpoint of image forming apparatus size reduction. Since the untransferred residual toner on the photoconductive drum is recovered by the developing apparatus, it is desired that a reversal developing method, that is, a developing method in which the polarity to which the photoconductive drum is charged is the same as the normal polarity to which toner is charged, is employed.
However, if a cleaner-less image forming apparatus such as the above described one which recovers (removes) the transfer residual toner remaining on the photoconductive drum after image transfer, and reuse it, is such an image forming apparatus that employs a contact charging apparatus which charges the surface of the photoconductive member by making contact with the photoconductive member, the toner particles in the untransferred residual toner, the polarity of which have been made opposite to the normal polarity to which the toner becomes charged, adhere to the contact charging apparatus while the transfer residual toner on the photoconductive member passes the charging station, that is, the contact nip between the photoconductive member and contact charging apparatus, contaminating the contact charging apparatus beyond the tolerable range. As a result, the photoconductive member is unsatisfactorily charged.
More specifically, normally, the toner as developer contains a certain amount of toner particles, the polarity of which is opposite to the normal toner polarity, although the amount is relatively small. Further, some of the toner particles with the normal polarity are reversed in polarity, or reduced in the amount of charge, by the transfer bias, the electrical discharge from the recording medium separation, etc.
Thus, the untransferred residual toner contains the toner particles with the normal polarity, toner particles with the reverse polarity, and toner particles with a smaller amount of electrical charge Among these three types of toner particles, the toner particles with the reverse polarity and the toner particles with reduced electrical charge are likely to adhere to the contact charging apparatus while they are moving through the charging station, or the contact nip between the photoconductive drum and contact charging apparatus.
Further, in order to remove and recover the untransferred residual toner on the photoconductive drum (in order to clean the photoconductive drum) by the developing apparatus at the same time as a latent image on the photoconductive drum is developed by the developing apparatus, it is necessary that the toner particles in the untransferred residual toner on the photoconductive drum, which are being carried to the developing station through the charging station, are normal in polarity (for example, negative), and also that the amount of electrical charge they are holding is proper for them to be used by the developing apparatus to satisfactorily develop the electrostatic latent image on the photoconductive drum. The toner particles with the reverse polarity (for example, positive polarity) and the toner particles improper in the amount of electrical charge cannot be removed and recovered from the photoconductive drum by the developing apparatus, effecting unsatisfactory images.
An image defect traceable to the failed recovery of the positively charged toner particles by the developing apparatus is called a positive ghost, which is a problem peculiar to an image forming apparatus without a dedicated cleaning member. More specifically, without a dedicated cleaning member, the untransferred residual toner reaches the developing station past the charging member, while remaining distributed in the pattern of the electrostatic latent image. If the untransferred residual toner particles are satisfactorily removed, in the developing station, from the photoconductive drum by the developing apparatus while the next electrostatic latent image is developed by the developing apparatus, the pattern in which the untransferred residual toner particles are distributed is eliminated. However, if the residual toner particles fall to be satisfactorily removed, the pattern which the residual toner particles are distributed is not completely eliminated and appears across a transfer medium, overlapping with the following toner image, as the following toner image is transferred onto the transfer medium. As a result, the portions of the following toner image corresponding to the residual toner pattern appear darker; in other words, a ghost appears. Since this ghost is darker than the surrounding area, it is called a positive ghost.
The above described adhesion of the toner particles to the contact charging apparatus can be prevented by charging the untransferred residual toner, that is, a mixture of the toner particles with the normal polarity, toner particles with the reversal polarity, and toner particles with reduced electrical charge, with the use of means for controlling the electrical charge of the untransferred residual toner particles in polarity as well as amount, so that so that all the toner particles in the residual toner become normally charged, and uniform in the amount of electrical charge.
However, as the residual toner particles are charged by the toner charge controlling means in order to prevent them from adhering to the contact charging apparatus, the amount of the electrical charge of the residual toner particles becomes greater than the proper amount of electrical charge for the satisfactory development of the electrostatic latent image on the photoconductive drum, making it difficult for the residual toner particles to be removed and recovered by the developing apparatus in the developing station, at the same time as the developing process is carried out by the developing apparatus. As a result, some of the toner particles in the residual toner remain on the photoconductive drum and are transferred onto a recording medium, effecting image defects, as the following toner image is transferred onto the recording medium.
Further, in recent years, the user needs have diversified. As a result, the demand for an image forming apparatus capable of continuously forming images with a high printing ratio, such as photographic images, an image forming apparatus capable of forming color images with the use of a multilayer developing method or the like, and the like image forming apparatuses, has increased. In the case of such image forming apparatuses, a large amount of the residual toner is generated all at once, exacerbating the above described problems.
This problem can be solved by providing a cleaner-less image forming apparatus with a residual toner particle uniformizing means (first developer charging member) and a toner charge amount controlling means (second developer charging means), and applying predetermined DC voltages to the two means. The residual toner particle uniformizing means is a means for making uniform in polarity the transfer residual toner particles remaining on the photoconductive drum after the transfer of the toner image on the photoconductive drum, whereas the toner charge amount controlling means is a means for charging the residual toner particles on the photoconductive drum. In terms of the rotational direction of the photoconductive drum, the residual toner particle uniformizing means is positioned on the upstream side of the contact charging apparatus and on the downstream side of the transferring means, whereas the toner charge amount controlling means is positioned on the down stream side of the residual toner uniformizing means and on the upstream side of the contact charging apparatus. The details of this solution is disclosed in U.S. Pat. No. 6,421,512.
More concretely, the residual toner particles remaining on the photoconductive drum after the toner image transfer are uniformized by the residual toner uniformizing means, and then, the uniformized residual toner particles on the photoconductive drum are charged to the normal polarity by the toner charge amount controlling means. Thereafter, at the same time as the surface of the photoconductive drum is charged in the charging station by the contact charging apparatus, the residual toner particles are charged by the contact charging apparatus to the proper potential level for the toner particles to be removed and recovered from the photoconductive drum by the developing apparatus in the developing station at the same time as the developing process is carried out by the developing apparatus in the developing station. Then, the properly charged residual toner particles are recovered by the developing apparatus in the developing station.
To describe in more detail, the image forming apparatus is provided with two stationary brush, as the first (upstream) and second (upstream) developer charging members, which are disposed on the downstream side of the transferring means and on the upstream side of the charging means. To the first developer charging member, positive DC voltage (positive bias) is applied, whereas to the second developer charging member, negative DC voltage (negative bias) is applied. The negatively charged toner particles on the photoconductive member are absorbed by the first developer charging member, being thereby positively charged. As the amount of the negatively charged toner particles in the first developer charging member reaches the toner particle holding capacity of the first developer charging member, the toner particles in the first developer charging member are gradually expelled as positively charged toner particles, back onto the photoconductive member. Thus, all the residual toner particles on the area of the peripheral surface of the photoconductive member on the immediately downstream side of the first developer charging member have positive electrical charge. Then, all the charged residual toner particles on this area of the peripheral surface of the photoconductive member are efficiently charged to the negative polarity by the second developer charging member, since all the residual toner particles on this area have been positively charged by the first developer charging member. As a result, the residual toner particles are prevented from adhering to the charging means (charge roller).
Further, oscillatory voltage, more specifically, a combination of DC voltage and AC voltage, is applied to the charging means. Therefore, the electrical charge of the residual toner particles, which is relatively high in potential level after being charged by the second developer charging member, is removed by a certain amount by the charging means. As a result, the potential level of the residual toner particles reduces to the potential level (close to proper level for satisfactory development) at which the residual toner particles can be easily recovered by the developing apparatus, improving thereby the efficiency with which the residual toner particles are recovered by the developing apparatus.
However, the amount by which electrical charge is given to the residual toner particles remaining on the photoconductive drum after the toner image transfer significantly affected by the conditions of the environment in which an image forming apparatus is used, printing ratio, etc. Therefore, if the DC voltages applied to the first and second developer charging members are kept constant, the residual toner particles sometimes fails to be charged to the proper potential level for them to be removed and recovered by the developing apparatus. In such a case, the residual toner particles remaining on the photoconductive drum, that is, the toner particles which could not be removed and recovered by the developing apparatus, are transferred onto a transfer medium, effecting image defects, as a toner image is transferred onto the transfer medium.
Next, the phenomenon that the amount by which electrical charge is given to the residual toner particles is affected by the conditions of the environment in which an image forming apparatus is operated will be described in more detail. The electrical resistance of an electrically conductive brush or the like, which is used as a developer charging member, is greatly affected by the environmental conditions.
Therefore, the value of the bias applied to the electrically conductive brush or the like, as the developer charging member, is kept constant, the toner particles are not given the proper amount of electrical charge.
In other words,
a) In a low humidity/low temperature environment (L/L (15° C., 10% RH) environment), the electrical resistance of the developer charging member increases, reducing thereby the amount by which electrical charge is given to the residual toner by the developer charging member (reduction in charging performance). In the case of the first developer charging member, the amount of the force by which the first developer charging member attracts the residual toner, and the amount by which the first developer charging member can hold the residual toner particles, reduce, allowing a larger amount of the residual toner particles to reach and enter the second developer charging member, contact charging member, and developing apparatus, resulting in the generation of ghosts, and/or the contamination of the contact charging member. Further, the second developer charging member falls to give the proper amount of electrical charge to the residual toner particles, which results in the contamination of the contact charging member.
B) In a high humidity/high temperature environment (H/H (30° C., 80% RH) environment), the electrical resistance or the developer charging member decreases, allowing an excessive amount of electrical current to flow. Therefore, the amount by which electrical charge is given to the residual toner by the developer charging member is substantially increased (enhancement in charging performance). As a result, not only is the residual toner particles are given a large amount of electrical charge, but also the photoconductive drum is given a large amount of electrical charge; in other words, the first developer charging member injects an excessive amount of positive electrical charge into the photoconductive drum, effecting thereby image defects such as the negative ghosts, brush streaks, etc. Each of these image defects occurs because the photoconductive drum is charged to the polarity (positive polarity) opposite to the polarity to which the photoconductive drum is normally charged. On the contrary, in the case of the second developer charging member, it gives an excessive amount of negative electrical charge. Therefore, as the residual toner particles are charged by the contact charging member on the downstream side of the developer charging members, they fail to be uniformly charged; all the transfer particles are not charged to the predetermined level.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide an image forming apparatus in which all the transfer residual developer particles on the image bearing member are given proper electrical charge.
Another object of the present invention is to provide an image forming apparatus in which all the transfer residual developer particles on the image bearing member are given a proper amount of electrical charge regardless of the conditions of the environment in which the image forming apparatus is used.
Another object of the present invention is to provide an image forming apparatus compatible with a cleaner-less system, that is, a system lacking a dedicated cleaning means.
Another object of the present invention is to provide an image forming apparatus in which all the transfer residual developer particles are efficiently recovered by the developing means.
Another object of the present invention is to provide an image forming apparatus in which the transfer residual developer particles remaining on the image bearing member after image transfer do not cause the image bearing member to be unsatisfactorily charged, and also, do not cause image defects.
Another object of the present invention is to provide an image forming apparatus in which the pattern of the image formed on the image bearing member during the preceding image forming cycle of the image bearing member does not appear on the image bearing member during the following image forming cycle of the image bearing member.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the image forming apparatus in the first embodiment of the present invention, for showing the general structure thereof.
FIG. 2 is a schematic drawing of the combination of the photoconductive drum and charging roller, for showing the laminar structure of the charge roller.
FIG. 3 is a graph for showing the relationship between the absolute humidity in the environment in which the image forming apparatus is used, and the DC voltage applied to the transfer residual toner uniformizing means.
FIG. 4 is a graph for showing the relationship between the absolute humidity in the environment in which the image forming apparatus is used, and the DC voltage applied to the toner charge amount controlling means.
FIG. 5 is a schematic drawing of the image forming apparatus in the second embodiment of the present invention, for showing the general structure thereof.
FIG. 6 is a graph for showing the relationship among the total amount of the toner adhered to the photoconductive drum by development (printing ratio), the amount of the residual toner on the photoconductive drum, and the amount of electrical charge given to the residual toner on the photoconductive drum.
FIG. 7 is a graph for showing the relationship among the total amount of the toner adhered to the photoconductive drum by development (printing ratio), and the overall amount of the electrical charge given to the residual toner on the photoconductive drum.
FIG. 8 is a graph for showing the relationship between the total amount of the toner adhered to the photoconductive drum by development (printing ratio), and the amount by which the DC voltage applied to the residual toner uniformizing means is adjusted.
FIG. 9 is a schematic drawing of the image forming apparatus in the third embodiment of the present invention, for showing the general structure thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(Embodiment 1)
Hereinafter, the image forming apparatuses (image recording apparatuses) in accordance with the present invention will be described.
FIG. 1 is a schematic drawing of an example of an image forming apparatus in accordance with the present invention, for showing the general structure thereof. This example of an image forming apparatus is an electrophotographic laser beam printer employing a contact charging method, a reversal developing method, and a cleaning system without a dedicated cleaning means. The maximum size of the transfer medium usable with this image forming apparatus is A 3 .
(1) General Structure of printer
(a) Image Bearing Member
Designated by a reference numeral 1 is an electrophotographic photoconductive member in the form of a rotational drum (which hereinafter will be referred to as photoconductive drum). This photoconductive drum 1 is a negatively chargeable organic photoconductor (OPC). It is 60 mm in external diameter, and is rotationally driven about the axial line of the photoconductive drum supporting shaft, at a process speed (peripheral speed) of 100 mm/sec in the counterclockwise direction indicated by an arrow mark.
Referring to FIG. 2, which schematically shows the laminar structure of the photoconductive drum 1 , the photoconductive drum 1 comprises an aluminum cylinder 1 a (electrically conductive base member), and three functional layers coated in layers on the peripheral surface of the electrically conductive base member 1 a . The three layers are an undercoat layer 1 b , an electrical charge generating layer 1 c , and an electrical charge transferring layer 1 d , listing from the layer closest to the aluminum cylinder 1 a . The undercoat layer 1 b is for suppressing optical interferences and improving the fixation of the layer thereupon to the base member 1 a.
(b) Charging Means
Designated by a reference numeral 2 is a contact charging apparatus (contact charging device) as a charging means for uniformly charging the peripheral surface of the photoconductive drum 1 . In this embodiment, the charging means is a charge roller (roller type charging device).
The charge roller 2 is rotationally supported by an unshown pair of bearing members, by the lengthwise end portions of its metallic core 2 a , and is kept pressured toward the photoconductive drum 1 by a pair or compression coil springs 2 e so that its peripheral surface is kept pressed upon the peripheral surface of the photoconductive drum 1 in a manner to generate a predetermined amount of contact pressure. The charge roller 2 is rotated by the rotation of the photoconductive drum 1 . The contact nip between the photoconductive drum 1 and charge roller 2 constitutes the charging station a (charging nip).
To the metallic core 2 a of the charge roller 2 , charge bias, or voltage, which satisfies predetermined requirements, is applied from an electrical power sourge S 1 , so that as the photoconductive drum 1 is rotated, the peripheral surface of the photoconductive drum 1 is charged to predetermined polarity and potential level. In this embodiment, the charge voltage, as the charge bias, applied to the charge roller 2 is an oscillatory voltage, that is, a combination of DC (Vdc) and AC voltages. More specifically, it is the combination of
DC voltage of −500 V, and
AC voltage, which is 1 kHz and 1.5 kV in frequency f and peak-to-peak voltage Vpp, respectively, and has a sinusoidal waveform. With the application of this oscillatory voltage to the charge roller 2 , the peripheral surface of the photoconductive drum 1 is uniformly charged to −500 V (dark (unilluminated) area voltage Vd).
Referring to FIG. 2, which is a schematic drawing for showing the laminar structure of the charge roller 2 , the charge roller 2 is 330 mm in length, and comprises the aforementioned metallic core 2 a (supporting member), and three layers, that is, an undercoat layer 2 b , an intermediary layer 2 c , and a surface layer 2 d , which are placed in layers on the peripheral surface of the metallic core 2 a , in the listed order. The undercoat layer 2 b is for reducing the charging noises, and is formed of foamed substance such as sponge. The surface layer 2 d is a protective layer provided for preventing electrical leak even if the peripheral surface of the photoconductive drum 1 has defects such as pin holes.
More specifically, the specification of the charge roller 2 in this embodiment is as follows:
a. metallic core 2 a : a piece of stainless steel rod with a diameter of 6 mm;
b. undercoat layer 2 b : formed of foamed EPDM in which carbon has been dispersed; 0.5 g/cm 3 in specific gravity 10 2 -10 9 Ωcm in volumetric resistivity value; 3.0 mm in thickness, and 320 mm in length;
c. intermediary layer 2 c : formed of NBR in which carbon has been dispersed; 10 2 -10 6 Ωcm in volumetric resistivity value; and 700 μm in thickness; and
d. surface layer 2 d : formed of Toresin resin, a fluorinated compound, in which tin oxide and carbon have been dispersed; 10 7 -10 10 Ωcm in volumetric resistivity value; 1.5 μm in surface roughness (10 point average surface roughness Ra in JIS); and 10 μm in thickness.
Referring to FIG. 2, a reference numeral 2 f stands for a charge roller cleaning member. In this embodiment, the charge roller cleaning member is a piece of flexible film. This cleaning film 2 f is disposed in parallel to the lengthwise direction of the charge roller 2 , and is fixed, by one of its long edges, to a supporting member 2 g which oscillates a predetermined distance in the direction also parallel to the lengthwise direction of the charge roller 2 . Further, the cleaning film 2 f is positioned so that its portion adjacent to its free edge, that is, the edge by which it is fixed to the supporting member 2 g , forms a contact nip against the peripheral surface of the charge roller 2 . The supporting member 2 g is driven by a driving motor of the printer through a gear train so that it is oscillated by the predetermined distance in its lengthwise direction. As a result, the surface layer 2 d of the charge roller 2 is rubbed by the cleaning film 2 f . By this action of the cleaning film 2 f , the contaminants (microscopic toner particles, additives, and the like) adhering to the peripheral surface of the charge roller 2 are removed. The cleaning film 2 f is formed of resin, and triboelectrically charges the toner particles on the charge roller 2 to their normal polarity (negative polarity). Having been negatively charged, the toner particles return to the photoconductive drum 1 .
(c) Information Writing Means
Designated by a reference numeral 3 is an exposing apparatus as an information writing means for forming an electrostatic latent image on the peripheral surface of the charged photoconductive drum 1 . In this embodiment, it is a laser beam scanner employing a semiconductor laser. The exposing apparatus 3 scans (exposes) the uniformly charged peripheral surface of the rotating photoconductive drum 1 with a scanning laser beam L which it projects while modulating the laser beam L with the image formation signals sent to the printer from an unshown host such as an image reading apparatus. This scanning (exposing) is done at an exposing point b, or exposing station. As the result of the scanning of the uniformly charged peripheral surface of the rotating photoconductive drum 1 by this laser beam L, the portions of the peripheral surface of the photoconductive drum 1 illuminated by the laser beam L are reduced in potential level, sequentially effecting an electrostatic latent image in accordance with the image formation information written on the peripheral surface of the photoconductive drum 1 by the scanning laser beam L.
(d) Developing Means
A reference numeral 4 stands for a developing apparatus (developing device) au a developing means for developing (visualizing) an electrostatic latent image on the photoconductive drum 1 into a toner image by supplying developer 4 e to the electrostatic latent image. In this embodiment it is a reversal developing apparatus employing a two-component magnetic brush type developing method.
Designated by reference numerals 4 a and 4 b are a developer container and a nonmagnetic development sleeve, respectively. The development sleeve 4 b is rotationally disposed within the developer container 4 a with its peripheral surface partially exposed from the developer container 4 a . Designated by reference numerals 4 c , 4 d , 4 e , 4 f , and 4 g are a magnetic roller, a developer coating blade, a two-component developer, each of a pair of developer stirring members, and a toner hopper, respectively. The magnetic roller 4 c is stationarily disposed within the hollow of the development sleeve 4 b . The two-component developer 4 e is stored in the developer container 4 a . The developer stirring members 4 f are positioned in the bottom portion of the developer container 4 a . The toner hopper 4 g contains replenishing toner.
The two-component developer 4 e in the developer container 4 a is a mixture of toner and magnetic carrier, and is stirred by the developer stirring members 4 f . In this embodiment, the electrical resistance of the magnetic carrier is approximately 10 13 Ωcm, and its particle diameter is 40 μm. The toner is negatively charged by the friction between the toner and magnetic carrier.
The development sleeve 4 b is disposed in parallel to the photoconductive drum 1 so that the shortest distance (S-D gap) between the peripheral surfaces of the development sleeve 4 b and photoconductive drum 1 is maintained at 350 μm. Where the distance between the peripheral surfaces of the development sleeve 4 b and photoconductive drum 1 is shortest, and its adjacencies, constitute the development station c. The development sleeve 4 b is rotationally driven in such a direction that its peripheral surface moves in the direction opposite to the peripheral surface of the photoconductive drum 1 , in the development station c. A part of the two-component developer 4 e in the developer container 4 a is held to the peripheral surface of the development sleeve 4 b by the magnetic force of the magnetic roller 4 c in the development sleeve 4 b , forming a magnetic brush layer, that is, a layer of two-component developer 4 e . As the development sleeve 4 b is rotated, the magnetic brush layer moves with the peripheral surface of the development sleeve 4 b . and as it moves with the peripheral surface or the development sleeve 4 b , its thickness is reduced by the developer coating blade 4 d to a predetermined one, that is, the proper thickness for the magnetic brush layer to come into contact with the peripheral surface of the photoconductive drum 1 and properly rubs the peripheral surface of the photoconductive drum 1 , in the development station c. To the development sleeve 4 b , a predetermined development bias is applied from an electrical power sourge S 2 in this embodiment, the development bias, or development voltage, applied to the development sleeve 4 b is an oscillatory voltage, that is, a combination of DC (Vdc) and AC (Vac) voltages. More specifically, it is the combination of
DC voltage: −350 V, and
AC voltage, which is 8.0 kHz and 1.8 kV in frequency f and peak-to-peak voltage Vpp, respectively, and has a rectangular waveform.
Through the process described above, the two-component developer 4 e is coated in a thin layer on the peripheral surface of the rotating development sleeve 4 b , and is conveyed to the development station c, in which the toner portion of the developer 4 e is adhered to the selected portions, that is, the portions of the peripheral surface of the photoconductive drum 1 corresponding to the pattern of the electrostatic latent image, by the electrical field generated by the development bias. As a result, the electrostatic latent image is developed into a toner image. In this embodiment, the toner adheres to the exposed portions, that is, the illuminated portions, of the peripheral surface of the photoconductive drum 1 ; in other words, the electrostatic latent image is developed in reverse.
The amount of the electrical charge, which the toner particles have after being adhered to the peripheral surface of the photoconductive drum 1 , is −25 μC in the environment which is 23° C. in temperature, and 10.5 g/m 3 in absolute humidity.
As the development sleeve 4 b is further rotated, the portion of the thin layer of the developer on the development sleeve 4 b , which passed through the development station c, is conveyed back into the developer pocket in the developer container 4 a.
In order to keep the toner density of the two-component developer 4 c in the developer container 4 a within a predetermined approximate range, the following system is provided: The toner density of the two-component developer in the developer container 4 a is detected by an unshown toner density sensor, for example, an optical toner density sensor, and the toner hopper 4 g is driven in response to the toner density information detected by the sensor, so that the toner within the toner hopper 4 g is supplied to the two-component developer 4 e within the developer container 4 a . After being supplied to the two-component developer 4 e , the toner is stirred by the stirring members 4 f.
(e) Transferring Means and Fixing Means
Designated by a reference numeral 5 is a transferring apparatus. In this embodiment, the transferring apparatus 5 is a transfer roller. The transfer roller 5 is kept pressed upon the photoconductive drum 1 by the application of a predetermined amount of pressure, forming a compression nip against the peripheral surface of the photoconductive drum 1 . This compression nip constitutes the transfer station d. To this transfer station d, a transfer medium p (medium onto which image is transferred; recording medium), as medium which receives a toner image, is delivered from an unshown sheet feeding mechanism with a predetermined control timing.
As the transfer medium p is delivered to the transfer station d, it is nipped between the peripheral surfaces of the photoconductive drum 1 and transfer roller 5 , and is conveyed further while remaining nipped.
While the transfer medium p is conveyed through the transfer station d, being nipped by the peripheral surfaces of the photoconductive drum 1 and transfer roller 5 , transfer bias with the positive polarity, which is +2 kV in this embodiment, is applied to the transfer roller 5 from an electrical power sourge S 3 . As a result, the toner image on the peripheral surface of the photoconductive drum 1 is transferred, electrostatically and sequentially, onto the surface of the transfer medium p, as the transfer medium p is conveyed through the transfer station d, remaining nipped by the photoconductive drum 1 and transfer roller 5 . The polarity of the transfer bias, which is positive, is opposite to the normal polarity (negative polarity) to which toner particles becomes charged.
After receiving the toner image while being passed through the transfer station d, the transfer medium p is continually separated, starting from its leading end, from the peripheral surface of the photoconductive drum 1 , and is conveyed to the fixing apparatus 6 (for example, heat roller type fixing apparatus), in which the toner image is fixed. Thereafter the transfer medium p is outputted as a print or copy.
(2) Cleaner-less System and Controlling or Toner Charge
The printer in this embodiment is of a cleaner-less type. In other words, it is not equipped with a cleaning apparatus dedicated to the removal of the residual toner particles, that is, a small amount of toner particles remaining on the peripheral surface of the photoconductive drum 1 after the transfer of the toner image onto the transfer medium p. Thus, after the transfer, the residual toner particles on the peripheral surface of the photoconductive drum 1 are conveyed farther by the rotation of the photoconductive drum 1 through the charging station a and exposing station b, and to the development station c, in which they are removed (recovered) by the developing apparatus 4 at the same time as the development process is carried out by the developing apparatus (cleaner-less system).
In this embodiment, the development sleeve 4 b of the developing apparatus 4 is rotated in such a direction that in the development station c, the peripheral surface of the development sleeve 4 b moves in the direction opposite to the peripheral surface of the photoconductive drum 1 , as described before. Rotating the development sleeve 4 b in this manner is advantageous for the recovery of the residual toner particles on the peripheral surface of the photoconductive drum 1 .
Since the residual toner particles on the peripheral surface of the photoconductive drum 1 go through the exposing station b, the peripheral surface of the photoconductive drum 1 is exposed with the presence of the residual toner particles on the peripheral surface.
However, the amount of the residual toner particles is very small, and therefore, the presence of the residual toner particles does not greatly affect the exposing process, except for the following.
As described hereinbefore, in terms of polarity, the residual toner is the mixture of the normally charged (negatively charged) toner particles and reversely charged (positively charged) toner particles (reversal toner particles). Further, some of the charged toner particles have an insufficient amount of electrical charge. Thus, as the residual toner passes through the charging station a, the reversely charged toner particles and the insufficiently charged toner particles are adhered to the charge roller 2 , contaminating the charge roller 2 beyond the tolerable range, in other words, making it impossible for the charge roller 2 to satisfactorily charge the photoconductive drum 1 .
Further, in order to effectively remove the residual toner particles on the peripheral surface of the photoconductive drum 1 by the developing apparatus 4 at the same time as the developing process is carried out by the developing apparatus 4 , it is necessary that the residual toner particles on the photoconductive drum 1 , which are being conveyed to the development station c, are normal in polarity, and also that the amount of the electrical charge, which they hold, is proper for an electrostatic latent image on the photoconductive drum 1 to be satisfactorily developed by the developing apparatus. The reversely charged toner particles and the toner particles with an unsatisfactory amount of electrical charge cannot be removed (recovered) from the photoconductive drum 1 by the developing apparatus 4 , becoming the sourges of image defects.
Thus, the image forming apparatus in this embodiment is provided with a residual toner particle (transfer residual developer image) uniformizing means 8 (first developer charging member) and a toner (developer) charge amount controlling means 7 (second developer charging member) for making all the residual toner particles charged to the negative polarity, or the normal polarity. In terms of the rotational direction or the photoconductive drum 1 , the residual toner particle uniformizing means 8 is positioned on the immediate downstream side of the transfer station d, whereas the second developer charging member 7 is positioned on the downstream side of the residual toner particles uniformizing means 8 and on the upstream side of the charging station a.
Generally, the toner particle which was not transferred onto the transfer medium p from the photoconductive drum 1 in the transfer station d, that is, the residual toner on the photoconductive drum 1 , is the mixture of reversely charged toner particles and the toner particles with an improper amount of electrical charge. Thus, the toner particles in the residual toner are once cleared of electrical charge by the residual toner (residual developer image) uniformizing means 8 , and then, are charged to their normal polarity by the toner charge amount controlling means 7 . As a result, it is ensured that the residual toner does not adhere to the charge roller 2 and also that is completely removed and recovered from the photoconductive drum 1 by the developing apparatus 4 , being thereby prevented from generating the ghosts reflecting the pattern in which the residual toner remained adhered to the peripheral surface of the photoconductive drum 1 .
In this embodiment, the above described residual toner particle uniformizing means 8 and toner charge amount controlling means 7 are fibrous brushes, as electrodes, with a proper degree of electrical conductivity. They are positioned so that their actual brush portions remain in contact with the peripheral surface of the photoconductive drum 1
A reference numeral f stands for the contact area between the residual toner particle uniformizing means 8 and the peripheral surface of the photoconductive drum 1 , and a reference numeral e stands for the contact area between the toner charge amount controlling means 7 and the peripheral surface of the photoconductive drum 1 .
To the residual toner particle uniformizing means 8 , positive DC voltage is applied from an electrical power surge S 5 , and to the toner charge amount controlling means 7 , negative DC voltage is applied from an electrical power source S 4 . More specifically, in the environment which is 23° C. in temperature, and 10.5 g/m 3 in absolute humidity, DC voltages of +400 V and −800 V are applied to the residual toner particle uniformizing means 8 and toner charge amount controlling means 7 , respectively.
The residual toner particles, or the toner particles which remained on the photoconductive drum J in the transfer station d after the transfer of the toner image onto the transfer medium p, reach the contact area f between the residual toner particle uniformizing means 8 and photoconductive drum 1 , in which they are uniformly distributed across the peripheral surface of the photoconductive member while being uniformized in the amount of electrical charge, at about 0 μC/g. After being uniformized in the distribution and amount of electrical charge, the residual toner particles reach the contact area e between the toner charge amount controlling means 7 and photoconductive drum 1 , in which all the residual toner particles are charged to their normal polarity, that is, the negative polarity, by the toner charge amount controlling means 7 .
With all of the residual toner particles charged to the negative polarity, or the normal polarity, the mirror force of the residual toner particles in relation to the photoconductive drum 1 is greater. Therefore, when the peripheral surface of the photoconductive drum 1 is charged in the contact area a, or the charging station, between the charge roller 2 and photoconductive drum 1 , with the presence of the residual toner particles on the peripheral surface of the photoconductive drum 1 , the residual toner particles are prevented from adhering to the charge roller 2 . The amount of the electric charge given to the residual toner particles, for this purpose, by the toner charge amount controlling means 7 needs to be approximately twice or more, compared to the proper amount of the electrical charge which the toner particles hold for developing an electrostatic latent image. In the environment which is 23° C. in temperature, and 10.5 g/m 3 in absolute humidity, it is −70 μC/g. Further, even if a small amount of toner particles adheres to the charge roller 2 , the toner particles are charged to their normal polarity by the friction between them and cleaning film 2 f , being therefore returned from the charge roller 2 onto the photo conductive drum 1 .
Next, the recovery of the residual toner during the developing process will be described. As described above, the developing apparatus 4 is of a cleaner-less type which removes the residual toner by the developing apparatus 4 at the same time as the developing process is carried out by the developing apparatus 4 . In the environment which is 23° C in temperature, and 10.5 g/m 3 in absolute humidity, the amount of the electrical charge, which the toner particles hold after being transferred onto the peripheral surface of the photoconductive drum 1 from the charge roller 2 , is −25 μC/g
Here, the relationship between the recovery of the residual toner particles and the amount of the electrical charge given to the transfer residual toner particles to recover them by the developing apparatus 4 , under the development conditions in this embodiment, is shown in Table 1.
TABLE 1
Charge Amount
Collection property
−10.0
NG
−12.5
G
−15.0
G
−30.0
G
−40.0
G
−45.0
G
−50.0
NG
In comparison to the amount (−25 μC/g) of the electrical charge given to the toner to develop an electrostatic latent image, the amount of the electrical charge given to the residual toner particles on the photoconductive drum 1 to recover them by the developing apparatus 4 needs to be 0.5-1.8 times. However, in consideration of the fact that the residual toner particles must be prevented from adhering to the charge roller 2 , it is desired that the residual toner is given a greater amount of negative electrical charge, that is, −70 μC/g, by the toner charge amount controlling means 7 . In order to recover the residual toner with a large amount of negative electrical charge by the developing apparatus 4 , it is desired that the residual toner particles are electrically discharged by the charge roller 2 ,
Here, the relationship between the amount of the electrical charge, which the toner particles on the photoconductive drum 1 , which had given an electrical charge of −70 μC/g, had after it had passed by the charge roller 2 , and the peak-to-peak voltage Vpp of the AC voltage applied to the charge roller 2 , is shown Table 2. It is evident from Table 2 that the greater the peak-to-peak voltage Vpp of the AC voltage, the greater the amount by which electrical charge is removed from the residual toner particles on the photoconductive drum 1 .
TABLE 2
Applied AC Volt.
Charge Amount (μC/g)
1000
−68.0
1200
−45.0
1400
−35.0
1600
−24.0
1800
−12.0
2000
−7.0
In order to charge the peripheral surface of the photoconductive drum 1 , an AC voltage (1 kHz in frequency; 1.5 kV in peak-to-peak voltage Vpp) was applied to the charge roller 2 . Thus, the electrical charge of the residual toner particles was removed by the function of the AC voltage; the amount of the electrical charge of the residual toner particles was reduced to −30 μC/g as the residual toner particles went through the charging station a. During the developing process, the residual toner particles on the areas of the photoconductive drum 1 which were nut to be developed by toner, were recovered by the developing apparatus 4 because of the above described reason.
In other words, while the residual toner particles on the photoconductive drum 1 were conveyed from the transfer station d to the charging station b, they were rectified in polarity by the toner charge amount controlling means 7 so that all the residual toner particles became normal, that is, negative, in polarity, being thereby prevented from adhering to the charge roller 2 . Then, in the charging station b, at the same time as the peripheral surface 1 was charged by the charge roller.
However, the amount of the electrical charge which toner holds is substantially affected by the environment in which an image forming apparatus is used Therefore, in order to control the amount of the electrical charge which the residual toner particles acquire in the above described cleaner-less system, it is necessary to take into consideration the environment in which an image forming apparatus is used, in particular, the absolute humidity of the environment. Thus, in this embodiment, the image forming apparatus was provided with a temperature/humidity sensor 9 for detecting the temperature and relative humidity within the image forming apparatus. The sensor 9 was disposed within the image forming apparatus and inputted the information regarding the internal temperature and relative humidity or the image forming apparatus into a control circuit 10 . The control circuit 10 calculated the absolute humidity of the environment in which the image forming apparatus was used, from the inputted temperature and relative humidity, and adjusted, according to the condition (absolute humidity) of the environment in which the image forming apparatus was used, the DC voltages applied to the residual toner particle uniformizing 8 and toner charge amount controlling means 7 .
[Calculation of Absolute Humidity]
The absolute humidity x is obtained from the following equation:
x= 0.622 ×T×ps /( p−T×ps ) (kg/kg′) (1)
T: relative humidity
t: dry environment temperature (° C).
Further, the relative humidity T (which is assumed to stabilize at 760 mmHg) is obtained from the following equation based on the water vapor partial pressure:
T=p/ps (%) (2)
P: water vapor partial pressure (mmHg) in humid air
ps: water vapor partial pressure (mmHg) of humidity saturated air.
P: total pressure of the humid air (constant at 760 mmHg)
Next, the relationship between the DC voltage applied to the residual toner particle uniformizing means 8 and the absolute humidity will be described.
When the absolute humidity is no less than 18.0 g/m 3 , the amount of the electrical charge of the residual toner particles immediately after the residual toner particles have passed the transfer station d is approximately 0 μC/g. Thus, if the potential level of the DC voltage applied to the residual toner particles uniformizing means 8 is +350, the residual toner particles is sometimes made positive in polarity (reverses in polarity) by the residual toner particle uniformizing means 8 , and therefore, cannot be satisfactorily recovered by the developing apparatus 4 in the following image forming process, which is a problem.
On the other hand, when the absolute humidity is no more than 5.8 g/m 3 , the amount of the electrical charge of some of the residual toner particles becomes approximately 0 μC/g, and that of the others becomes 50 μC/g, as the residual toner particles pass the transfer station d. Thus, if the potential level of the DC voltage applied to the residual toner particle uniformizing means 8 is +350, the amount of the electrical charge of the residual toner particles sometimes cannot be reduced to approximately 0 μC/g by the residual toner particle uniformizing means 8 , and therefore 7 the residual toner particles cannot be satisfactorily recovered by the developing apparatus 4 in the following image formation process, which is a problem.
Thus, in this embodiment, the control circuit 10 of the image forming apparatus was provided with referential data such as those shown in FIG. 1 . The control circuit 10 calculated the absolute humidity of the environment in which the image forming apparatus was used, from the temperature and relative humidity inputted from the temperature/humidity sensor 8 , and adjusted, according to the calculated absolute humidity of the environment in which the image forming apparatus was used and the referential data, the DC voltage applied to the residual toner uniformizing 8 . With the provision of this arrangement, the above described effect of the transfer residual toner particle uniformizing means 8 upon the residual toner particles remained stable regardless of the environment in which the image forming apparatus was used.
Next, the relationship between the DC Voltage applied to the toner charge amount controlling means 7 and the absolute humidity will be described.
When the potential level of the DC voltage applied to the toner charge amount controlling means 7 in the environment in which the absolute humidity was no less than 18.0 g/m 3 was −800 V, the amount of the electrical charge of the residual toner particles sometimes unnecessarily increased in the contact area e between the toner charge amount controlling means 7 and photoconductive drum 1 , making it impossible for the residual toner particles to be satisfactorily recovered by the developing apparatus 4 in the following image forming process, which was a problem.
On the other hand, when the potential level of the DC voltage applied to the toner charge amount controlling means 7 in the environment in which the absolute humidity was no more than 5.8 g/m 3 was −800 V, the amount of the electrical charge of the residual toner particles sometimes could not be reduced to a desired value in the contact area e between the toner charge amount controlling means 7 and photoconductive drum 1 . As a result, the residual toner particles adhered to the surface of the contact charge roller 4 , or the like problems occur.
Thus, in this embodiment, the control circuit 10 of the image forming apparatus was provided with referential data such as those shown in FIG. 4 . The control circuit 10 calculated the absolute humidity of the environment in which the image forming apparatus was used, from the temperature and relative humidity inputted from the temperature/humidity sensor 9 , and adjusted, according to the calculated absolute humidity of the environment in which the image forming apparatus was used, and the referential data, the DC voltage applied to the toner charge amount controlling means 7 . With the provision of this arrangement, the above described effect of the toner charge amount controlling means 7 upon the residual toner particles remained stable regardless of the environment in which the image forming apparatus was used.
As was demonstrated by the above described embodiment of the present invention, according to the present invention, the DC voltages applied to the toner charge amount controlling means 7 and residual toner particle uniformizing means 8 are adjusted according to the absolute humidity of the environment in which an image forming apparatus is used. Therefore it is possible to provide an image forming apparatus in which the unsatisfactory charging of the image bearing member and/or the formation of a defective image do not occur, in spite of its employment of a cleaner-less system, regardless of the conditions of the environment in which the image forming apparatus is used.
Further, if necessary, it is possible to structure an image forming apparatus so that the DC voltage adjusted according to the absolute humidity of the conditions of the environment in which an image forming apparatus is used, is limited to either the DC voltage applied to the toner charge amount controlling means 7 or the DC voltage applied to the residual toner particle uniformizing means 8 .
(Embodiment 2)
The basic structure of the image forming apparatus (printer) in this embodiment is the same as that in the first embodiment.
As is evident from the description of the first embodiment, by controlling the amount of the electrical charge of the transfer residual toner particles, with the application of proper DC voltages to the toner charge amount controlling means 7 and/or residual toner particle uniformizing means 8 , the residual toner particles, that is, the toner particles remaining on the portion of the photoconductive drum 1 which has just passed the transfer station d, can be efficiently recovered by the developing apparatus 4 , at the same time as the developing process is carried out by the developing apparatus 4 .
However, the amount of the electrical charge, which the transfer residual toner particles on the photoconductive drum 1 hold immediately after they have passed the transfer station d, is affected by the printing ratio. Therefore, the amount of the electrical charge given to the residual toner particles by the toner charge amount controlling means 7 and/or residual toner particle uniformizing means 8 (primarily, residual toner particle uniformizing means 8 ) in order to clean the photoconductive drum 1 with the use of the developing apparatus 4 at the same time as the developing process is carried out by the developing apparatus 4 , should be adjusted according to the printing ratio.
Thus, in this embodiment, the information regarding the printing ratio was detected by the exposing means 3 as an image writing means, as shown in FIG. 5, and this information was inputted into the control circuit 10 . The control circuit 10 adjusted the DC voltages applied to the toner charge amount controlling means 7 and residual toner particle uniformizing means 8 according to the inputted information regarding the printing ratio.
Hereinafter, this embodiment will be described in detail.
FIG. 6 shows the relationship among the printing ratio, that is, the amount or the toner particles which are on the photoconductive drum 1 immediately after the development process was carried out by the developing apparatus 4 , the amount of the residual toner particles which are on the portion of the photoconductive drum 1 which has just passed the transfer station d, the amount of the electrical charge which the toner particles, which are on the photoconductive drum 1 immediately after the development process, hold, and the amount of the electrical charge which the residual toner particles on the portion of the photoconductive drum 1 , which has just passed the transfer station d, hold. It is evident from this graph that the greater the printing ratio, the greater the amount of the residual toner particles, but the smaller the amount of the electrical charge the residual toner particles hold. More specifically, when the printing ratio was small, that is, 0.1 g/m 2 , the amount of the residual toner particles was 3×10 −2 g/m 2 and the amount of the electrical charge or the residual toner particles was 45 μC/g, whereas when the printing ratio was large, that is, 0.6 g/m 2 , the amount of the residual toner particles was 6×10 −2 and the amount of the electrical charge of the residual toner particles was 10 μC/g.
It is also evident from this graph that when the printing ratio was 0.1 g/m 2 , the amount of the electrical charge of the residual toner particles was approximately 45 μC/g, whereas when the printing ratio was 0.6 g/m 2 , it was approximately 10 μC/g. In consideration of the fact that the total amount of the electrical charge which the residual toner holds per unit area is the product of the amount of the electrical charge of each residual toner particle and the amount of the transfer residual toner particles, it is evident that the total amount of the electrical charge which the residual toner holds when the printing ratio was 0.1 g/m 2 was approximately the same as that when the printing ratio was 0.6 g/m 2
FIG. 7 shows the relationship between the printing ratio, that is, the amount of the toner on the portion of the photoconductive drum 1 which has just passed the developing apparatus 4 , and the total amount of the electrical charge of the residual toner per unit area. It is evident from this graph that the total amount of the electrical charge which the residual toner held when the printing ratio was 0.1 g/m 2 was approximately the same as that when the printing ratio was 0.6 g/m 2 , but the total amount of the electrical charge the residual toner held was affected by the printing ratio, being the largest when the printing ratio was 0.3 g/m 2 . This means that in order to adjust the amount of the electrical charge of the residual toner particles to a desired amount with the use or toner charge amount controlling means 7 and residual toner particle uniformizing means 8 , the DC voltages applied to the toner charge amount controlling means 7 and residual toner particle uniformizing means 8 should be adjusted according to the printing ratio.
Thus, in this embodiment, the control circuit 10 was provided with referential data such as those shown in FIG. 8, and the DC voltage applied to the residual toner particle uniformizing means 8 was adjusted by the control circuit 10 , by the amount shown in FIG. 8, based on the DC voltages applied to the residual, toner particle uniformizing means 8 when the printing ratios were 0.1 g/m 2 and 0.6 g/m 2 , and also, according to the information regarding the printing ratio inputted into the control circuit 10 from the exposing means 3 and the referential data.
As described above, according to this embodiment of the present invention, the information regarding the printing ratio is detected by the exposing means 3 as an image writing means, and the DC voltages applied to the toner charge amount controlling means 7 and transfer residual toner particle uniformizing means 8 (primarily, transfer residual toner particle uniformizing means 8 ) are adjusted according to the printing ratio. Therefore, it is possible to provide a cleaner-less image forming apparatus in which the unsatisfactory charging of the image bearing member and the formation of a defective image do not occur regardless of the printing ratio.
If necessary, it is possible to structure an image forming apparatus so that the DC voltage adjusted according to the printing ratio is limited to either the DC voltage applied to the toner charge amount controlling means 7 or the DC voltage applied to the residual toner particle uniformizing means 8 , in particular, the residual toner particle uniformizing means 8 .
(Embodiment 3)
This embodiment is the combination of the first and second embodiments. More specifically, referring to FIG. 9, the image forming apparatus is provided with the temperature/humidity sensor 9 , which is disposed within the image forming apparatus, and the DC voltages applied to the toner charge amount controlling means 7 and residual toner particle uniformizing means 8 (primarily, residual toner particle uniformizing means 8 ) are adjusted according to the absolute humidity of the environment in which the image forming apparatus is used, calculated from the temperature and humidity detected by the temperature/humidity sensor 9 , and also, according to the information regarding the printing ratio obtained from the amount of the exposure by the exposing means 3 as an information writing means.
With the provision of the arrangement, it is possible to provide a cleaner-less image forming apparatus in which the unsatisfactory charging of the image bearing member and the formation of a defective image do not occur.
If necessary, it is possible to structure an image forming apparatus so that the DC voltage adjusted according to the absolute humidity of the environment in which the image forming apparatus is used, calculated from the temperature and humidity detected by the temperature/humidity sensor 9 disposed within the image forming apparatus, and the information regarding the printing ratio obtained from the amount of the exposure by the exposing means 3 as an information writing means, is limited to either the DC voltage applied to the toner charge amount controlling means 7 or the DC voltage applied to the residual toner particle uniformizing means 8 , in particular, the DC voltage applied to the residual toner particle uniformizing means 8 .
(Embodiment 4)
In this embodiment, the voltages applied to the developer charging members 7 and 8 are controlled according to the zone of the environmental factor detected by an environment sensor. The image bearing member, charging means, information writing means, developing means, transferring means, and fixing means in this embodiment are the same in structure and operation as those in the first embodiment shown in FIG. 1 . Therefore, they will not be described here.
Also in this embodiment, the main assembly of the image forming apparatus is provided with an environment sensor 9 as was in the first embodiment. The specific zone of the factors (temperature and humidity) of the environment in which the main assembly of the image forming apparatus is being used is determined based on the temperature and humidity measured by the environment sensor 9 . To describe in more detail, the range of the environmental factor, which in this embodiment is the absolute humidity, is divided into seven zones (Table 3), and to which zone the environment in which the main assembly of the image forming apparatus is being used belongs is determined based on the absolute humidity calculated from the temperature and humidity measured by the environment sensor 9 . With the division of the range or the humidity of the environment in which the image forming apparatus is used, into a certain number of zones, it is possible to reduce the capacity of the memory in which the relationship between the changes in the environmental conditions, and the value to which the voltages applied to the toner charge amount controlling means 7 and residual toner particle uniformizing means 8 are adjusted, is stored, compared to the first embodiment.
TABLE 3
Absolute Humidity and Environmental Zones
Zone Nos.
humidity zone
1
<1.4 (L/L)
2
1.4-5.8
3
5.8-10.5
4
10.5-15.0
5
15.0-18.0
6
18.0-21.6
7
≧21.6 (H/H)
Next, the cleaner-less system and toner charge amount control, in this embodiment, will be described.
The printer in this embodiment is of a cleaner-less type. In other words, it is not equipped with a cleaning apparatus dedicated to the removal of the residual toner particles, that is, a small amount of toner particles remaining on the peripheral surface of the photoconductive drum 1 after the transfer of the toner image onto the transfer medium p. Thus, after the transfer, the residual toner particles on the peripheral surface of the photoconductive drum 1 are conveyed farther by the continual rotation of the photoconductive drum 1 , through the charging station a and exposing station b, and to the development station C, in which they are removed (recovered) by the developing apparatus 4 at the same time as the development process is carried out by the developing apparatus (cleaner-less system).
Since the residual toner particles on the peripheral surface of the photoconductive drum 1 go through the exposing station b, the exposing process is carried out with the presence of the residual toner particles on the peripheral surface. However, the is amount of the residual toner particles is very small, and therefore, the presence of the residual toner particles does not greatly affect the exposing process, except for the following.
That is, as described before, in terms of polarity, the residual toner is the mixture of the normally charged (negatively charged) toner particles and reversely charged (positively charged) toner particles (reversal toner particles). Further, some of the toner particles have an insufficient amount of electrical charge. Thus, as the residual toner passes through the charging station a, the reversal toner particles and the insufficiently charged toner particles adhere to the charge roller 2 , contaminating the charge roller 2 beyond the tolerable range, in other words, making it impossible for the charge roller 2 to satisfactorily charge the photoconductive drum 1 .
Further, in order to efficiently remove the residual toner particles on the peripheral surface of the photoconductive drum 1 by the developing apparatus 4 at the same time as the developing process is carried out by the developing apparatus 4 , it is necessary that the residual toner particles on the photoconductive drum 1 , which are being conveyed to the development station c, are normal in polarity, and also that the amount of the electrical charge, which they hold, is the proper amount for an electrostatic latent image on the photoconductive drum 1 to be satisfactorily developed by the developing apparatus 4 .
The reversal toner particles and the toner particles with an unsatisfactory amount of electrical charge cannot be removed (recovered) from the photoconductive drum 1 by the developing apparatus 4 , becoming the sourges of image defects.
Further, in recent years, the user needs have become multifarious, making it likely for images with a high printing ratio, such as photographic images, to be continually printed. As images with a high printing ratio are continually printed, a large amount of the residual toner is generated all at once, exacerbating the above described problems.
Thus, in order to uniformly redistribute the residual toner particles across the photoconductive drum 1 , and assure that all the residual toner particles become charged to the negative polarity, that is, the normal polarity, the image forming apparatus is provided with the first and second developer charging members 8 and 7 , which are disposed on the downstream side of the transfer station d in terms of the rotational direction of the photoconductive drum 1 , and the upstream side of the charging station a.
In this embodiment, the first and second developer charging members 8 and 7 are fibrous brushes with a proper degree of electrical conductivity. They are positioned so that their actual brush portions remain in contact with the peripheral surface of the photoconductive drum 1 .
To the first developer charging member 8 , positive voltage (positive bias) is applied from an electrical power sourge S 5 .
A reference numeral f stands for the contact area between the first developer charging member 8 and the peripheral surface of the photoconductive drum 1 . Among the residual toner particles on the photoconductive drum 1 , which are different in polarity, the particles with virtually no electrical charge and the negatively charged particles are absorbed by the first developer charging member 8 . However, the amount of the toner which the first developer charging member 8 can hold is limited. Thus, as the residual toner particles saturate the first developer charging member 8 , they gradually escape from the first developer charging member 8 , adhere to the peripheral surface of the photoconductive drum 1 , and are conveyed. At this point in an image forming operation, the residual toner particles are positive in polarity, and also, through the above described process, the residual toner particles have been evenly distributed on the photoconductive drum 1 , being prevented from being carried downstream all at once by a large amount. Further, the first developer charging member 8 plays the role of reducing the potential level of the residual toner particles on the photoconductive drum 1 to virtually zero volt, providing difference in potential level between the residual toner particles on the photoconductive drum 1 and the voltage applied to the second developer member 7 , which will be described later, so that the residual toner particles are given a sufficient amount of proper electrical charge.
To the second developer charging member 7 , negative voltage is applied from the electrical power sourge S 5 S 4 . A reference numeral e stands for the contact area between the second developer charging member 7 and the peripheral surface of the photoconductive drum 1 .
While the residual toner particles on the photoconductive drum 1 pass the second developer charging member 7 , all of them are made negative, that is, normal, in polarity. Since all of the residual toner particles have been made positive in polarity, and the potential level on the photoconductive drum 1 has reduced to virtually zero volt, by the first developer charging member 8 , all of the residual toner particles are more efficiently turned negative in polarity by the second developer charging member 7 . Since all of the residual toner particles are made negative, that is, normal, by the second developer charger member 7 , the mirror force of the residual toner particles relative to the photoconductive drum 1 is greater when the peripheral surface of the photoconductive drum 1 is charged with the presence of the residual toner particles on the peripheral surface of the photoconductive drum 1 , in the charging station a, which is located further downstream. Therefore, the residual toner particles are prevented from adhering to the charge roller 2 ; in other words, they go through the charging station a without adhering to the charge roller 2 . After passing by the charge roller 2 , they are recovered by the developing device at the same time as the developing process is carried out by the developing device.
At this time, the developing/cleaning process, that is, the process in which the residual toner particles are removed from the peripheral surface of the image bearing member, in the charging station, at the same time as the developing process is carried out by the developing apparatus, will be described.
The developing/cleaning process is a process in which the transfer residual toner particles on the photoconductive member are recovered by the developing apparatus, using the fog prevention bias. More specifically, after the transfer of a toner image on the photoconductive member, the portion of the photoconductive member, from which the toner image has been transferred, is charged with the presence of the residual toner on the photoconductive member, and an electrostatic latent image is formed thereon by exposure, also with the presence of the residual toner particles. Then, while this electrostatic latent image is developed by the developing apparatus, those residual toner particles, which are on the areas (non-image areas) of the peripheral surface of the photoconductive member, which are not to be developed by toner, are removed (recovered) by the developing apparatus, using the fog prevention bias (difference Vback in potential level between DC voltage applied to developing apparatus and potential level of peripheral surface of photoconductive member).
In order to recover the residual toner particles on the photoconductive drum 1 into the developing apparatus 4 with the use of the process described above, the residual toner particles must have a proper amount of electrical charge.
However, for the purpose of preventing the residual toner particles from adhering to the charge roller 2 as described above, the greater the amount of the negative electrical charge given to the residual toner particles, the better. On the other hand, for the purpose of recovering the residual toner particles with a large amount of negative charge by the developing apparatus 4 , the residual toner particles should be cleared of electrical charge by the charge roller 2 .
After being given a large amount of negative charge by the second developer charging member 7 , the electrical charges of the residual toner particles are removed by the AC voltage (1,000 Hz in frequency f; 1.400 V in peak-to-peak voltage Vpp) applied to the charge roller 2 . Thus, after going through the charging station a, the amount of the electrical charge which the residual toner particles hold is approximately the same as the electrical charge which the toner particles for development hold. Therefore, in the developing process, the transfer residual toner particles on the areas of the photoconductive drum 1 to which toner particles are not to be adhered, are recovered by the developing apparatus 4 , for the reason given above.
Next, the characteristic aspect of this embodiment, that is, the method for controlling the voltage applied to the developer charging members, according to the environmental conditions, will be described in detail.
In order to determine the proper value for the voltage applied to the first developer charging member in the various environments, the inventors of the present invention printed 30,000 A4 size copies, using different voltages as the voltage applied to the first developer charging member 7 , and evaluated the copies. The voltage applied to the second developer charging means 8 during this operation was fixed at −800 V.
The results of the evaluation are given in Table 4.
TABLE 4
Voltage applied to First Charging Member and
Image Defects
Applied Voltage (V)
200
250
300
350
400
450
500
H/H
Roller
N
F
G
G
G
G
G
Contam-
ination
30° C.
Un-
N
G
G
G
G
G
G
transfer
Ghost
80%
Negative
G
G
G
N
N
N
N
RH
Ghost
L/L
Roller
N
N
N
F
G
G
G
Contam-
ination
15° C.
Un-
N
N
F
G
G
G
G
transfer
Ghost
10%
Negative
G
G
G
G
G
N
N
RH
Ghost
G: good
F: image defect may occur.
N: image defect occurs.
In the H/H environment, the charge roller contamination occurred when the voltage applied to the second developer charging member was no more than 250 V, and in the L/L environment, it occurred when the voltage applied to the second developer charging member was no more than 350 V. It is conceivable that this charge roller contamination occurred due to the following reason, that is, when the voltage applied to the first developer charging member was lower than a certain level, the difference in potential level between the first developer charging member and photoconductive member was insufficient for the first developer charging member to be enabled to temporarily retain the residual toner particles and expel them back onto the peripheral surface or the photoconductive member evenly across the peripheral surface, at a satisfactory level. Therefore, a large amount of the residual toner particles entered the second developer charging member.
Also, when the voltage applied to the first developer charging member was lower than a certain level, the potential level of the peripheral surface of the photoconductive member could not be sufficiently reduced to provide a sufficient amount of difference in potential level between the second developer charging member and photoconductive member. Therefore, the residual toner particles were not given a proper amount of electrical charge by the second developer charging member. In other words, all the residual toner particles were not given a sufficient amount of negative electrical charge. Thus, those residual toner particles, which did not receive a sufficient amount of negative electrical charge, adhered to the charge roller.
Further, the ghost traceable to the residual toner was also caused by the insufficient amount of difference in potential level between the first developer charging member and photoconductive member, because when the difference in potential level between the first developer charging member and photoconductive member was insufficient, the first developer charging member was not enabled to temporarily retain the residual toner particles and expel them back onto the photoconductive member evenly across the peripheral surface, at a satisfactory level, and therefore, a large amount of the residual toner particles entered the developing device all at once, making it impossible for the developing device to recover it.
These problems could be virtually eliminated by increasing the voltage applied to the first developer charging member to provide a sufficient amount of difference in potential level between the first developer charging member and photoconductive member in order to improve the charging performance of the first developer charging member.
As for the negative ghost, in the H/H environment, it occurred when the voltage applied to the first developer charging member was not less than 350 V, and in the L/L environment, it occurred when the voltage applied to the first developer charging member was not less than 450 V. It is conceivable that this negative ghost occurred for the following reason. That is, when the voltage applied to the first developer charging member increased beyond a certain level, the difference in potential level between the first developer charging member and photoconductive member became excessive; in other words, the difference in potential level became large enough to charge the surface of the photoconductive member to the polarity (positive polarity) opposite to the polarity to which it is normally charged. This problem could be solved by preventing the first developer charging member from excessively charging the residual toner particles, by reducing the voltage applied to the first developer charging member.
As is evident from the above descriptions, if the difference in potential level between the first developer charging member and photoconductive member is not proper, image defects occur. The reason for the presence of a difference of approximately 100 V in the proper voltage value between the H/H and L/L environments is that the electrical resistance value of the developer charging member is affected by the environmental conditions. A substance such as the material for the brush used as the developer charging member easily absorbs moisture, and therefore, in the high humidity environment, the first developer charging member easily absorbs moisture, declining in electrical resistance. Naturally, as the electrical resistance of the first developer charging member declines, it becomes easier for electrical current to flow through the first developer charging member, improving thereby the first developer charging member in charging performance. On the contrary, in the low humidity environment, the brush increases in electrical resistance, declining therefore in charging performance. Thus, in the H/H environment, the negative ghost is likely to occur, whereas in the L/L environment, the charge roller contamination and the ghost traceable to the residual toner are likely to occur, even if the two environmental conditions are kept the same in terms of the voltage applied to the first developer charging member.
Thus, in this embodiment, the environment, in which the main assembly of the image forming apparatus was placed, was evaluated, and the voltage applied to the first developer charging member was controlled according to the conditions of the environment in which the main assembly of the image forming apparatus was placed.
As described hereinbefore, the main assembly of the image forming apparatus in this embodiment was provided with an environment sensor. Further, the range of the environmental factor (absolute humidity in this embodiment) was divided into seven zones. Based on the information obtained by the environment sensor, it was determined to which zone of the absolute humidity the environment in which the main assembly of the image forming apparatus was disposed belonged.
In this embodiment, the voltage applied to the first developer charging member was adjusted according to the absolute humidity. Referring to Table 5, in the H/H environment (for example, 30° C., 80% RH, 216 g/cm 3 in absolute humidity), the electrical resistance of the first developer charging member was relatively low, and therefore, a relatively low voltage of 300 V was applied, whereas in the L/L environment (for example, 15° C.; 10% RH; 1.064 g/cm 3 ), the electrical resistance of the first developer charging member was relatively high, and therefore, a relatively high voltage of 400 V was applied. Further, the linear interpolation was used to make it possible for the voltage applied to the first developer charging member, to be controlled in response to even a minute change in the absolute humidity.
TABLE 5
Voltage Applied to First Charging Member
Env'tal Zones
1
2
3
4
5
6
7
Abs. humidity
? (see Table 3)
Applied
400
390
365
344
326
312
300
Voltages
With the provision of the above described arrangement, the charging performance of the first developer charging member was kept constant at the proper level regardless of the changes in the environment. Therefore, the residual toner particles were given the proper amount of electrical charge, and also, the potential level of the photoconductive member was reduced to the proper level, preventing the formation of images which suffered from defects such as ghosts traceable to the charge roller contamination. In other words, it was possible to form satisfactory images regardless of the changes in the environment.
(Embodiment 5)
The structure of the image forming apparatus in this embodiment is about the same as that in the fourth embodiment. However, in order to improve the image bearing member in image quality and service life, not only is the voltage applied to the first developer charging member made controllable according to the environmental conditions, but also the voltage applied to the second developer charging member is made controllable according to the environmental conditions.
In the case of the system in the fourth embodiment, only the voltage applied to the first developer charging member was controlled according to the environmental conditions. As a result, the image defects did not occurred as long as the number of the printed copies did not exceed 30,000. In this embodiment, in order to search for the possibility of further increasing the service life of the image bearing member, 60,000 copies were printed while observing whether or not the image defects occurred.
Also in the fourth embodiment, the voltage applied to the second developer charging member was a fixed bias of −800 V. As a result, the image defects traceable to the charge roller contamination did not occur in either environmental condition. However, as the number of copies reached 60,000 in this embodiment, the image defects occurred in the L/L environment. It is conceivable that this problem occurred because the electrical resistance of the developer charging member changed due to the combination of the conductivity deterioration resulting from the increase in the cumulative apparatus usage, and the changes in the environmental conditions.
Thus, in this embodiment, the relationship between the voltage applied to the second developer charging member and the image quality was studied in relation to the environmental conditions. As for the voltage applied to the first developer charging member in this embodiment, it was the same as that in the fourth embodiment in other words, in the H/H environment, it was 300 V, whereas in the L/L environment, it was 400 V. The results of the study are shown in Table 6.
TABLE 6
Applied Voltage to Second Charging Member and Images
−650
−700
−750
−800
−850
−900
−950
H/H
Roller
N
F
G
G
G
G
G
30° C.
Contam-
80% RH
ination
Potential
G
G
G
F
F
N
N
Instability
L/L
Roller
N
N
F
G
G
G
G
15° C.
Contam-
10% RH
ination
Potential
G
G
G
G
G
F
F
Instability
G: good
F: image defect slightly occurs.
N: image defect occurs.
In the H/H environment, the charge roller contamination occurred when the voltage applied to the second developer charging member was no more than −700 V, whereas in the L/L environment, it occurred when the voltage applied to the second developer charging member was no more than −800 V. This occurred because the difference in potential level between the second developer charging member and photoconductive member was not enough for the second developer charging member to give the residual toner particles a sufficient amount of electrical charge. As is evident from Table 6, this problem could be eliminated by improving the charging performance or the second developer charging member by increasing the voltage applied to the second developer charging member. However, when the voltage applied to the second developer charging member increased beyond a certain level, the potential level to which the second developer charging member charged the residual toner particles became unstable, which was a problem. This occurred for the following reason. That is, the increase in the voltage applied to the second developer charging member beyond a certain level made the second developer charging member excessive in charging performance, overcharging not only the residual toner particles but also the photoconductive member; in other words, the residual toner particles as well as the photoconductive member were given an excessive amount of negative electrical charge. As a result, when the residual toner particles were charged by the charge roller on the downstream side of the developer charging members, they failed to be uniformly charged; all the residual toner particles were not charged to the desired potential level. In the H/H environment, this problem occurred when the voltage applied to the second developer charging member was no less than −800 V, whereas in the l,/L environment, it occurred when the voltage applied to the second developer charging member was no less than −700 V.
As will be evident from the above explanation, the proper value for the voltage applied to the second developer charging member in the H/H environment was −750 V, whereas that in the L/L environment was −850 V. Here, the presence of the difference between the H/H and L/L environments, in terms of the proper value for the voltage applied to the second developer charging member, is due to the fact that in the H/H environment, the second developer charging member became excessive in charging performance because the second developer charging member, that is, a brush, absorbed moisture in the H/H environment and declined in electrical resistance, whereas in the L/L environment, it increased in electrical resistance, declining therefore in charging performance.
Thus, in this embodiment, the voltage applied to the second developer charging member was controlled according to the environmental condition as shown in Table 7, in the similar manner to the manner in which the voltage applied to the first developer charging member was controlled in the preceding embodiment. As a result, it became possible to reliably output satisfactory images, that is, the images which did not suffer from either of the above described two problems, until the service life of the image bearing member expired.
TABLE 7
Applied Voltage to First and
Second Charging Member
Env'tal Zones
1
2
3
4
5
6
7
Abs. Humidity
? (see Table 3)
First
400
390
365
344
326
312
300
Member
Second
−850
−840
−820
−800
−780
−760
−750
Member
In this embodiment, the range of the environmental condition in terms of the absolute humidity was divided into seven zones, and the voltages applied to the first and second developer charging members were adjusted according to only the absolute humidity, using the linear interpolation. However, the usage of the linear interpolation is not mandatory. In other words, instead of using the linear interpolation based on the seven zones, such a method that the temperature and humidity ranges are divided into a greater number of finer zones than the seven zones, and that in each zone, the voltages are kept at the levels predetermined for each zone, may be employed.
(Others)
1) In the preceding embodiments, the amount (μC/g) of the electrical charge of toner was measured using the so-called blow-off method.
2) The choice of the contact charging apparatus 2 does not need to be limited to the charging apparatus in the preceding embodiments, which employed a charge roller. In other words, the charging member which the contact charging apparatus 2 employs may be a magnetic brush, a fur brush, or the like.
3) The choice of the exposing means 3 as an information writing means does not need to be limited to the laser beam scanner in the preceding embodiments. It may be one of the digital exposing apparatuses other than the laser beam scanner. For example, it may be an LED array, a combination of a light sourge, such as a fluorescent lamp, and a liquid crystal shutter, or the like. Also, it may be an analog exposing apparatus which focally projects the image of an original onto an image bearing member.
4) The image bearing member 1 may be an electrostatically recordable dielectric member. In such a case, the surface of the dielectric member is uniformly charged to predetermined polarity and potential level, and then, an electrostatic latent image is written thereon by selectively removing the electrical charge, in the pattern reflecting the image formation information, with the use of a charge removing means (information writing means), for example, a charge removal needle array, an electron gun, etc.
5) The image receiving member may be an intermediary transfer member such as an intermediary transfer drum, an intermediary transfer belt, etc., instead of the above described transfer medium p. In such a case, a toner image is transferred twice; first, from an image bearing member onto an intermediary transfer member, and then, from the intermediary transfer member onto a transfer medium.
6) The waveform of the AC voltage of the bias applied to the contact charging apparatus 2 or developing apparatus 4 may be optional; it may be sinusoldal, rectangular, triangular, or the like. The AC bias includes voltage with such a rectangular waveform that is formed by periodically turning on and off a DC power sourge.
7) Although a stationary brush was used as the developer charge amount controlling means in the preceding embodiments, the choice of the developer charge amount controlling means does not need to be limited to a stationary brush. It may be a rotational brush, a sheet of electrically conductive substance, etc.
As described above, according to the present invention, an image forming apparatus employing a cleaner-less system, that is, a system which recovers the transfer residual developer (residual toner) remaining on the image bearing on the image bearing member after the image transfer process, by the developing means, in the developing station, at the same time as the developing process is carried out by the developing means, and which reuses the recovered transfer residual developer, comprises the combination of a developer particle uniformizing means (first developer charging member) and a developer charge amount controlling means (second developer charging member), for evenly redistributing the transfer residual developer particles across the peripheral surface of the image bearing member while controlling the triboelectrical charge of the developer particles, wherein the DC voltages applied to the two developer charging members are adjusted according to the environmental conditions affected by the temperature and relative humidity (moisture amount), which are detected by the temperature/humidity sensor disposed within the image forming apparatus, and also, according to the information regarding the printing ratio, so that the triboelectrical charge of the transfer residual developer particles is rectified in polarity and amount by the first and second developer charging means, making it possible for all the transfer residual developer particles to be recovered in the developing station by the developing apparatus at the same time as the developing process is carried out by the developing means. Therefore, the occurrence of image defects, in particular, the ghosts reflecting the transfer residual developer, is prevented.
More specifically, in the high temperature/high humidity environment, the voltages applied to the developer charging members are made slightly lower than the voltages applied thereto in the normal environment, preventing the developer charging members, the electrical resistance of which reduces due to the high humidity, from becoming excessive in charging performance, whereas in the low temperature/low humidity environment, the voltages applied to the developer charging members are made slightly higher than the voltages applied thereto in the normal environment, compensating for the decline in the charging performance of the developer charging members, which occurs due to the low temperature/low humidity. Therefore, the developer charging members are enabled to always properly charge the transfer residual developer, in polarity and amount.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. | An image forming apparatus includes an image bearing member, a first charging member for charging a residual developer on the image bearing member, a second charging member for charging the residual developer, an environmental condition detector, and a controller. The first charging member is disposed downstream of the transferring device and up stream of the charger, with respect to a movement direction of the image bearing member. A voltage having a polarity opposite to a polarity of the developer is applied to the first charging member. The second charging member is disposed downstream of the first charging member and upstream of the charger. A voltage having a polarity like a polarity of the developer is applied to the second charging member. The controller, in accordance with an output of the detector, controls at least one of the voltages applied to the first and second charging members. | 6 |
PRIORITY CLAIM
This invention claims priority from PCT Application Serial No. PCT/CN2013/081580 filed Aug. 15, 2013, which claims priority to Chinese Application Serial No. 201310291745.3 filed Jul. 11, 2013, which is hereby incorporated by reference.
TECHNICAL FIELD
This invention belongs in the technical field of boats. Specifically, it is a dual-purpose boat.
BACKGROUND INFORMATION
Existing boats have singular purposes. For example, sightseeing boats are designed with cabins located above the surface of the water, so passengers can only view above-water scenery. For underwater sightseeing, semi-submersible vessels were invented. These semi-submersible vessels have a state of flotation between conventional above-water boats and fully submersible boats. These semi-submersible vessels comprise a flotation raft and a cabin, with the flotation raft located in a fixed position at the upper part of the cabin. By manipulating the relationship between the boat's weight and its buoyancy, this design allows the flotation raft and the top of the cabin to float atop the surface of the water while the sealed cabin is located below the surface, allowing passengers in the cabin to see the underwater scenery. However, with the cabin located underwater in this semi-submersible vessel, it is impossible to operate or dock in shallow water, and can be dangerous to operate at high speeds.
SUMMARY OF THE INVENTION
To overcome the disadvantages of the prior art, the invention provides a dual-purpose vessel that can operate both as a semi-submersible vessel and as an ordinary boat.
To solve the problems outlined above, the invention has the following technical solution: a type of dual-purpose boat with a hull and cabin connected by a lifting mechanism. The hull or cabin, or both, contains a buoyancy regulating structure.
The aforementioned buoyancy regulating structure includes space to hold water or air, and an inlet valve for water inflow into the space and a pump or a drain valve for water discharge.
The aforementioned space to hold water or air can be located at the bottom of the hull, at the bottom of the cabin, or at the bottom of both the hull and cabin.
Between the aforementioned hull and cabin, there is a stopper structure designed to limit their horizontal relative displacement. This stopper structure has a guide post and a guide sleeve which are mutually matched.
The aforementioned guide sleeve and guide post can be structured in at least one of the following two forms. In the first form, the guide sleeve and post have square lateral sections which are matched in both size and shape, and there is an alignment bearing on both sides of the guide sleeve where the guide post rests. In the second form, the lateral sections of the guide sleeve and post are matched in a dovetail shape.
The aforementioned lifting mechanism can function via winding engines, worm gear, or rack and pinion.
There are one, two or more of the aforementioned lifting mechanism with winding engines, placed at the rear or symmetrically on both sides of the cabin. The winding engines have a dragline secured at one end. Either the winding engines are fastened to the hull and the other end of the dragline is fastened to the cabin, or the winding engines are fastened to the cabin and the other end of the dragline is fastened to the hull.
The aforementioned hull can be H-shaped, U-shaped, O-shaped, circular, or square.
The aforementioned the hull comprises two side wings, which are matched according to the width of the boat's cabin. The cabin is mounted between the two wings, effectively serving as the connection between the two wings. Alternatively, the hull comprises two side wings as well as a beam connecting the two side wings. The two side wings would be matched according the width of the boat's cabin, and the cabin would be mounted in the space between the two side wings and the beam.
The aforementioned hull has a sensor that detects the boat's vertical position relative to the surface of the water and controls the buoyancy of the boat.
This invention can be used as a regular boat, or if the cabin is lowered, this invention becomes a semi-submerged vessel that can be used for operational purposes or underwater sightseeing. When the invention enters shallow water or needs to navigate at high speed, the cabin can be raised to prevent beaching and to reduce resistance. The operation of this invention is simple and expands the single function of current boats.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the ion's three-dimensional view in its semi-submersible state.
FIG. 2 shows the invention's three-dimensional view in its regular, above-water state.
FIGS. 3 to 5 show the invention in its different states as it transitions from a regular above-water boat into a semi-submersible boat.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The figures below, in conjunction with the following explanation of the invention's implementation, will provide a more detailed description of the invention.
As shown by FIGS. 1 and 2 , the invention is a dual-purpose boat, including hull ( 1 ) and cabin ( 2 ). Between the hull ( 1 ) and cabin ( 2 ), there is a lifting mechanism ( 3 ). The hull or cabin, or both, contains a buoyancy regulating structure.
The buoyancy regulating structure includes a space ( 41 ) which holds water or air, as well as a pump ( 42 ), which can act as both an inlet valve to let water in or a discharge valve to drain water out. This pump is located on the lower part of the space ( 41 ). The pump ( 42 is submersible. The space ( 41 ) which holds water or air is located at the bottom of the hull ( 1 ), at the bottom of the cabin ( 2 ), or at the bottom of both the hull ( 1 ) and cabin ( 2 ). The effect of this is to adjust the balance between boat's buoyancy and its weight, so that both states can be achieved. In the figures drawn below, the space ( 41 ) is drawn at the bottom of the hull ( 1 ).
The lifting mechanism ( 3 ) can function via winding engines, worm gear, rack and pinion, or any device capable of raising and lowering the cabin ( 2 ) against the hull ( 1 ). In the example shown in the figures, the lifting mechanism with a winding engine is employed. It comprises a winding engine ( 31 ) and a dragline ( 32 ), with one end tied to the winding engine ( 31 ). The winding engine ( 31 ) is secured to the hull ( 1 ), and the other end of the dragline ( 32 ) is fastened to the mounting hole or fixed collar ( 21 ) on the upper part of the cabin ( 2 ). When the winding engine ( 31 ) tightens the dragline ( 32 ), the downward tension pulls the cabin ( 2 ); when the winding engine ( 31 ) loosens the dragline, the cabin ( 2 ) rises due to its buoyancy. Another configuration could be that the winding engine ( 31 ) is fastened to the upper part of the cabin ( 2 ), while the other end of the dragline ( 32 ) is fastened to the hull ( 1 ), which would result in the same effect.
When the lifting mechanism ( 3 ) functions via worm gear or rack and pinion, both the ascending force and descending force of the cabin ( 2 ) are provided by the lifting mechanism ( 3 ). Lifting mechanisms with worm gear or rack and pinion are common structures and technicians in this domain could design and apply these structures according to actual needs.
There can be one lifting mechanism ( 3 ) located at the rear of the cabin ( 2 ). It is preferable that at least two lifting mechanisms ( 3 ) are located symmetrically on both sides of the cabin ( 2 ) to make it ascend and descend more steadily. When the winding engine is employed, it is best to install at least two lifting mechanisms with winding engines symmetrically located on both sides of the cabin ( 2 ) to prevent the cabin ( 2 ) from tilting when it ascends and descends. This is shown in the figures drawn below. Depending on the size of the cabin ( 2 ), the number of lifting mechanisms with winding engines can be increased as necessary.
There is a stopper structure placed between the hull ( 1 ) and cabin ( 2 ) to limit their horizontal relative displacement. This stopper structure has a guide post and a guide sleeve which are mutually matched. The post can slide up and down within the sleeve. The shape of the lateral sections of the guide sleeve and post can be designed according to actual needs as long as they serve to limit the relative horizontal displacement between the hull ( 1 ) and the cabin ( 2 ). It is preferable to have the stopper structure take at least one of the following two forms. In the first form, the guide sleeve and post have square lateral sections which are matched in both size and shape, and there is an alignment bearing on both sides of the guide sleeve where the guide post rests. In the second form, the guide sleeve and post have matching lateral sections in the shape of a dovetail. In the example shown by the figures, the cabin ( 2 ) has a guide post ( 23 ) with a dovetail shape on the rear side, and the hull ( 1 ) has a matching guide sleeve ( 14 ) and guide post at the corresponding position on the connecting beam ( 12 ). The guide post and sleeve are mutually matched in both size and shape to fasten the cabin ( 2 ) and the hull ( 1 ) to guarantee that they cannot be separated. Meanwhile, the cabin ( 2 ) has a square guide post ( 22 ) on both sides, and the hull ( 1 ) has a square guide sleeve ( 15 ) at the corresponding position on both side wings ( 11 ). The guide post and sleeve are matched in both size and shape, and there is an alignment bearing ( 13 ) on both sides of the square guide sleeve ( 15 ), against which the square guide post ( 22 ) is placed. This stopper structure assists in controlling the ascending and descending of the cabin ( 2 ) to ensure that the cabin moves along its path stably.
The shape of the hull ( 1 ) can be designed according to actual needs, but must ensure that the cabin ( 2 ) can remain balanced whether ascending or descending. The hull ( 1 ) can be H-shaped, U-shaped, O-shaped, circular, or square. The cabin ( 2 ) is positioned in the center of the hull ( 1 ). The hull ( 1 ) can include two parallel side wings, whose width matches the width of the cabin ( 2 ). The cabin ( 2 ) is situated in the space between the two wings, serving as a connection between the two wings. In this case demonstrated by the figures below, the two sides of the cabin ( 2 ), the hull ( 1 ), and the two side wings of the hull ( 1 ) are connected through stopper structures, and the lateral sections of guide post and sleeve are matched in both size and shape to ensure that they will not loosen horizontally. In the figures, the hull ( 1 ) is H-shaped, with two side wings ( 11 ), as well as a connecting beam ( 12 ) between the two wings. The width of the two side wings ( 11 ) is matched according to the width of the cabin ( 2 ), so the cabin ( 2 ) is situated between the two side wings ( 11 ) and the connecting beam ( 12 ).
The pump ( 42 ) and lifting mechanism ( 3 ) can be operated manually, or a vertical buoyancy sensor can be installed in the cabin ( 1 ). This buoyancy sensor can automatically transmit information to the cabin's control panel, which then adjusts the functions of the pump ( 42 ) and the lifting mechanism ( 3 ) in order to automatically control the boat's buoyancy, allowing the cabin ( 1 ) to smoothly float atop the surface of the water.
Functionality of Design
FIG. 3 shows the cabin ( 2 ) on top of the surface of the water ( 5 ), with only the counterweight underwater. There is only air inside the space ( 41 ).
FIG. 4 shows that when the cabin needs to be submerged, first, the inlet valve at the bottom part of the space ( 41 ) is opened to allow water to flow into the space. The specific amount of water that enters the space ( 41 ) depends on the buoyancy of the part of the cabin that is descending. When the weight of the water in the space ( 41 ) becomes greater than the buoyancy created by the cabin ( 2 ), the lifting mechanism ( 3 ) begins to operate (for example, the winding engine ( 31 ) begins to tighten the dragline ( 32 ), and its direction of movement is as shown by the arrow in FIG. 4 .), causing the cabin ( 2 ) to start descending. At the same time, water is continuously flowing through the inlet valve into the space ( 41 ), causing the buoyancy and weight affecting the entire vessel to reach a balance. When the cabin ( 2 ) descends to the determined level, the lifting mechanism ( 3 ) stops, the inlet valves close, and the boat is in its semi-submerged state, as shown by FIG. 5 , allowing personnel to start underwater operations or allowing tourists to view the underwater scenery.
When the boat needs to be returned to its normal state, engage the lifting mechanism ( 3 ) (for example, the winding engine's power discharging device). Through its natural buoyancy, the boat cabin ( 2 ) can rise above water level ( 5 ). At the same time, start the pump ( 42 ), drawing the water out of the space ( 41 ), until the boat returns to its original position above water. | This invention is type of dual-purpose boat, including cabin and hull. This boat is unique in that between the cabin and hull there is a lifting mechanism connecting the hull and cabin, at least one of which has been set up with a buoyancy regulating structure. This invention can be used as a regular boat, or if the cabin is lowered, this invention becomes a semi-submerged vessel that can be used for operational purposes or underwater sightseeing. When the invention enters shallow water or needs to navigate at high speed, the cabin can be raised to prevent beaching and to reduce resistance. The operation of this invention is simple and expands the single function of current boats. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of Brazilian Patent Application No. PI1101701-5, filed Apr. 18, 2011, the entire disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a sealing system for a refrigerator and, more particularly, to a sealing system located between the doors of a refrigerator and its acclimatized chambers and of the kind that comprises a gasket to be inserted in a receiving channel existing also between the doors of a refrigerator and its acclimatized chambers.
BACKGROUND OF THE INVENTION
Sealing the door of the refrigerated compartment of a refrigerator or freezer is essential for grating proper and efficient refrigeration. The inlet of hot air in the generated refrigerated compartment and the outlet of cool air from the same impact the efficiency in pre-serving the refrigeration, the energy consumption (excessive activation of the compressor), and may still cause water formation in the inside and outside of the compartment due to condensation or unwanted ice formation.
The most commonly used way to carry out the sealing of the refrigerator door is by means of a magnetic gasket. This gasket generally comprises an attachment portion and a sealing bag housing a magnet. The attachment part is received in a receiving channel disposed in a peripheral inner portion of the refrigerator door, and the magnet is housed in the sealing bag which contacts a metallic flange of the body of the refrigerator in order to assure the proper sealing of the door.
Considering the desired properties for the gasket, a number of different constructions and geometries were proposed for a sealing gasket. Those constructions are known, for example, from documents PI 9913633-3, U.S. Pat. Nos. 6,227,634, 6,526,698, US 2004/0244297, US 2006/0188690 and PI 0503971-1.
Document PI 9913633-3 describes a gasket whose attachment portion comprises at least three fixing noses, one of the noses presenting, with the vertical, a more obtuse intermediate angle than the other two fixing noses.
Document U.S. Pat. No. 6,227,634 describes a gasket developed for better resisting to the compression and traction forces acting over it as the door is being moved. The solution provided in this document consists of using two different materials for making part of the sealing bag.
Document U.S. Pat. No. 6,526,698 describes a sealing system for the refrigerator door, wherein the receiving channel of the attachment portion of the gasket has an asymmetric profile, so as to facilitate gasket assembling.
Document US 2004/0244297 describes profiles for the sealing bag of a gasket. According to this document, an additional flap in the bag is predicted which transmits magnetic tension force from the magnet region to the attachment portion region of the gasket.
Document US 2006/0188690 describes a gasket made from a specific material, which would have better extrusion properties.
Finally, document PI 0503971-1 describes a gasket having an attachment portion with a curved profile and a sealing bag subdivided into a side sealing bag, an intermediate sealing bag, a main sealing bag, three secondary sealing bags, and a magnet compartment.
Although the listed documents represent efforts in the sense of achieving a construction of an efficient sealing gasket with long-lasting service life, it remains the search for a solution that allies cost efficiency and manufacturing ease to a gasket having good properties of variation absorption and traction resistance, compression resistance and torsion resistance.
OBJECTS OF THE INVENTION
In view of the foregoing, it is one object of the present invention to provide a sealing system between at least a refrigerator door and the respective acclimatized chambers that provides an efficient sealing, but which maintains an acceptable manufacturing cost.
It is another object of the present invention to provide at least a low cost sealing gasket with good properties of variation absorption and traction resistance, compression resistance and torsion resistance.
It is another object of the present invention to provide at least one type of a sealing gasket having a long service life, which presents little distress when subjected to the efforts of compression and traction.
Finally, another object of the present invention is to provide at least a model of sealing gasket that can be installed in both the refrigerator door, and the front face of the refrigerator.
SUMMARY OF THE INVENTION
The present invention achieves the above objects by means of sealing system for a refrigerator, which comprises at least one gasket, at least one movable door of refrigerator and at least one fixed cabinet of refrigerator. At least one gasket comprises a tubular body formed by at least one attaching end and by at least one sealing body. At least one groove is defined in at least one movable door or at least one fixed cabinet. At least one rib is de-fined in at least one movable door or at least one fixed cabinet.
The gasket is physically coupled to the at least one movable door or to the at least one fixed cabinet through at least one groove, and the gasket is able to perform a hermetic sealing between at least one movable door and at least one fixed cabinet through the physical contact thereof with at least one rib.
Preferably, and in accordance with a preferred construction, the gasket comprises a cross-sectional tubular body defined by at least one attaching end and at least one sealing body. The attaching end of the gasket has an essentially triangular shape, and is pro-vided with at least one contact lateral projection, and at least an inner span portion. Still preferably, the sealing body comprises a tubular profile surrounding wall. The surrounding wall comprises at least an essentially semi-circular contacting groove and at least one inner damper. The damper comprises at least one resilient structure disposed within the perimeter defined by the surrounding wall. Optionally, the groove has a triangular profile and is essentially surrounding relative the acclimatized chamber of the refrigerator, and the rib has an essentially semi-circular profile.
Also preferably, the gasket is made either of elastomer or polymer.
In general, the gasket attachment, either to the movable door or to fixed cabinet, occurs by inserting the attachment end of the gasket in at least one groove defined by at least one movable door or at least one fixed cabinet. In this sense, the sealing provided by the gasket occurs through hermetically contacting the at least one fragment of the contact groove of the sealing body with at least one rib defined by at least one movable door or at least one fixed cabinet.
Optionally, it is provided another version for the sealing system for refrigerator, which comprises at least one gasket, at least one movable door of refrigerator and at least one fixed cabinet of refrigerator, at least one gasket comprising a tubular body formed by at least one attaching appendage and by at least one sealing body, and at least one rib is defined in at least one movable door, the gasket being physically coupled to the movable door, and being able to perform hermetic seal between at least one movable door and at least one fixed cabinet through the physical contact thereof with at least one fixed cabinet.
In this construction, the gasket comprises an essentially tubular body defined by at least one attaching appendage and at least one sealing body. The attaching appendage comprises a curved profile, in a similar format to the “C” letter.
In general, the gasket is attached to at least one movable door through the attaching appendage, the attaching appendage is inserted between the inner body and the outer body composing the movable door. The attaching appendage is fitted, in a surrounding manner, in the perimetral end of the inner body of the movable door. Preferably, at least one attaching appendage length of the gasket is contacted with the thermo-isolating expandable foam between the inner body and the outer body composing the movable door.
Also preferably, the gasket herein reported is made either of elastomer or polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
Figures show:
FIG. 1 illustrates the cross-sectional section of the preferred construction of the gasket belonging to the sealing system for refrigerator;
FIG. 2 illustrates, in a schematic manner, a first gasket arrangement of FIG. 1 ;
FIG. 3 illustrates, in a schematic manner, a second gasket arrangement of FIG. 1 ;
FIG. 4 illustrates the cross-sectional section of the optional construction of the gasket belonging to the sealing system for refrigerator; and
FIG. 5 illustrates, in a schematic manner, a gasket arrangement of FIG. 4 ;
DETAILED DESCRIPTION OF THE INVENTION
According to the concepts of the present invention, it is disclosed a sealing system for refrigerator comprising at least one gasket 1 , which is disposed between at least one movable door 2 and at least one fixed cabinet 3 . The gasket 1 is intended to prevent escape of fluids (in this case, air) existing within an acclimatized chamber to the external environment, while it also has the function of preventing the inlet of external fluids within a refrigerated chamber. That is, the gasket 1 has the function of sealing, in a hermetic manner, the internal environment of a refrigerated chamber from the external environment.
Said gasket 1 can be attached to the movable door 2 , or further to the fixed cabinet 3 . The movable door 2 , which preferably belongs to a refrigerator (not shown) is preferably attached in a pivoting manner to the fixed cabinet 3 .
According to the proposed in the present invention, the novelties evinced herein provide two different aspects, namely: interaction of gasket 1 with the movable door 2 , and interaction of gasket 1 with the fixed cabinet 3 . In this context, it is ascertained that the gasket 1 is preferably made of a material having mechanical resiliency, such as elastomers or polymers.
Preferred Construction
The preferred construction of the sealing system for refrigerator, according to the concepts of the present invention, is illustrated in FIGS. 1 , 2 and 3 .
In this preferred construction, the gasket 1 basically comprises a tubular body whose cross-sectional section comprises at least one attaching end 11 and at least one sealing body 12 .
The attaching end 11 which is directed to attach the gasket 1 to the movable door 2 ( FIG. 2 ) or to the fixed cabinet 3 ( FIG. 3 ) comprises an essentially triangular shape, and is provided with at least one contact lateral projection 110 , and at least an inner span portion 111 , which helps possible mechanical deformations that occur when attaching said gasket 1 .
The sealing body 12 comprises a surrounding wall 120 , which defines an essentially oblong tubular profile.
Said surrounding wall 120 further has a mechanical reinforcement 13 disposed adjacent between the attaching end 11 and the mentioned sealing body 12 .
The surrounding wall 120 comprises at least an essentially semi-circular contacting groove 121 and at least one inner damper 122 . In the preferred construction herein reported, the dampers 122 include resilient walls preferably arranged perpendicularly inside the perimeter defined by the surrounding wall 120 .
Although the gasket 1 has been detailed by portions composing it, it should further be evinced that all those portions are intact and joined. Thus, it is noticed that the gasket 1 can be industrially obtained by thermo-extrusion process or similar processes.
Attaching the gasket 1 , either to the movable door 2 or to the fixed cabinet 3 , occurs by inserting the attaching end 11 in at least one groove 4 . In this context, the groove 4 may, exclusively, exist on the movable door 2 or on the fixed body 3 . That is, the groove 4 may be made, in a selective and exclusive manner, either on the movable door 2 or on the fixed body 3 , but not in both of them.
The groove 4 has an essentially triangular profile and is surrounding (relative to the acclimatized chamber (not shown)).
The sealing provided by gasket 1 occurs by hermetically contacting at least a section of the sealing body 12 (in particular, the contacting groove 121 of the sealing body 12 of gasket 1 ) with at least one rib 5 . In this context, the rib 5 may exist, exclusively, on the movable door 2 or on the fixed body 3 . That is, the rib 5 may be made, in a selective and exclusive manner, either on the movable door 2 or on the fixed body 3 , but not in both of them.
The rib 5 has a profile that is analogous to the contacting groove profile 121 of the sealing body 12 , that is, an essentially semi-circular profile.
In FIG. 2 , it is illustrated the preferred construction of the sealing system herein reported, and the groove 4 is on movable door 2 and the rib 5 is on the fixed cabinet 3 . More specifically, the groove 4 is shaped on the inner face of the movable door 2 , in a surrounding manner (according to one of the acclimatized chambers present in the fixed cabinet 3 ). Also more specifically, the rib 5 is shaped on the outer face of the movable cabinet 3 , in a surrounding manner (according to one of the present acclimatized chambers).
In FIG. 3 , it is illustrated the preferred construction of the sealing system herein reported, the groove 4 being present on the fixed cabinet 3 and the rib 5 is present on the movable door 2 . Also more specifically, the groove 4 is shaped on the outer face of the movable cabinet 3 , in a surrounding manner (according to one of the present acclimatized chambers). Also more specifically, the rib 5 is shaped on the inner face of the movable door 2 , in a surrounding manner (according to one of the acclimatized chambers present in the fixed cabinet 3 ).
In a coherent assembly of the elements integrating the preferred construction of the sealing system herein reported, regardless of the variations described herein above, it is noticed that the gasket 1 is physically attached to the groove 4 through the attaching end 11 thereof. It is important to mention that the gasket 1 is independently made.
In this assembly, the lateral (side) projections 110 end up acting as locking elements, as the inner span portions 111 aid deformation (fitting during the housing) of the attaching end as a whole. This fixing takes place without the need of any separate element, besides occurring in a simple and efficient manner.
The gasket 1 is able to perform sealing and shock absorption relative the contact thereof with the rib 5 . Specifically, the contacting groove 121 is disposed in a aligned manner relative to the rib 5 . In the event of contact between the gasket 1 and said rib 5 (either on the movable door 2 , or on the fixed cabinet 3 ) the inner dampers 122 suffer from deformation and absorb potential impacts.
In this context, it remains noticing that the rib 5 , together with the contacting groove 121 , guarantees more robustness in what concerns absorption of variations of assembling process and positioning the movable door 2 relative to a fixed cabinet 3 . This characteristic also optimizes the state of the art, after all, the current assembly of movable door to fixed cabinets, according to the current state of the art, can undergo misalignments, and those alignments usually cause sealing problems of the refrigerated chambers of the current refrigerators.
According to this assembly, interacting the gasket 1 with the rib 5 occurs efficiently and dynamically.
As previously mentioned, one of the innovative aspects of the present invention refers to the interaction between the gasket 1 and the groove 4 1 (whether on the movable door, or on the fixed cabinet 3 ).
The great news about this aspect is the fact that the attachment of the gasket 1 to the groove 4 lacks magnets and similar items. The absence of those elements (magnets and the like) considerably reduces the cost for the production of refrigerators with the sealing system disclosed herein. Of course, not using magnets and similar elements is only possible due to the constructiveness of gasket 1 , and to the interaction between it and the groove 4 .
Another innovative aspect of the present invention, also mentioned herein above, relates to the interaction between the gasket 1 with the rib 5 (either on the movable door 2 , or on the fixed cabinet 3 ). The great news about this aspect is the fact of that any misalignments between the movable door 2 and the fixed cabinet 3 are fixed overcome by physical contact between the contacting groove 121 of gasket 1 and rib 5 .
The sealing between the movable door 2 and the fixed cabinet 3 occurs always when both are kept in contact, preferably by external forces. That is, the sealing between the movable door 2 and the fixed cabinet 3 , through the gasket 1 , is kept by a physical force capable of pressing the movable door 2 against the fixed cabinet 3 . In this sense, it should be noted that the source of physical force (not shown) comprises a source of physical force belonging to the current state of the art. Preferably, the following sources of physical force may be used: set of “male-female” locks disposed between the movable door 2 and the fixed cabinet 3 ; set of hinges with a torsion spring; among others.
Optional Construction
The optional construction of the sealing system for refrigerator, according to the concepts of the present invention, is illustrated in FIGS. 4 and 5 .
This is optional construction is fundamentally similar to the preferred construction described herein above, having only two different aspects over said construction.
The first differentiating aspect relates to the constructiveness of the gasket, hereinafter referenced as by indication 6 .
The gasket 6 comprises an essentially tubular body whose cross-sectional section comprises at least one attaching appendage 61 and at least one sealing body 62 .
The attaching appendage 61 , which is directed for attaching to a movable door 2 of the gasket 6 comprises a curved profile, preferably shaped similar to the “C” letter.
The sealing body 62 of the gasket 6 is similar to sealing body 12 of the gasket 1 , that is, it comprises a surrounding that defines an essentially oblong tubular profile, which presents at least one contacting groove and inner dampers.
The second differentiating aspect relates to the interaction between the gasket 6 and the movable door 2 previously recited. In this sense, it remains the evidence that the gasket 6 , unlike the gasket 1 , can only be attached to the movable door 2 (which is exempt from the previously described groove 4 ).
Therefore, and according to optional construction of the sealing system disclosed herein, the gasket 6 is attached to a movable door 2 of a refrigerator or the like (not shown) through the attachment appendage 61 , which is inserted between the inner body 21 and outer body 22 composing the door 2 .
As it is known to the ones skilled in the art, a refrigerator door or the like comprises an external body (normally metallic and that can be finished) and an inner body (usually plastic, which are shaped to the shelves and the like), these bodies being joined with the aid of an expandable heat-insulating foam (typically, polyurethane).
Therefore, and in accordance with the optional construction under discussion, the attaching appendage 61 of the gasket 6 is fitted, in a surrounding manner, to the perimetral end of the inner body 21 of door 2 before said inner body 21 is, usually metallic, and an inner body attached to the outer body 22 . Thus, at least one attaching appendage length 61 of the gasket 6 is contacted with the expandable thermo-insulating foam, therefore getting attached to the door 2 in a permanent manner, thus ensuring a perfect fit.
It should further be mentioned that, as the gasket 6 is directly attached to the door 2 , the rib 5 is also formed always shaped to the fixed cabinet 3 .
The other aspects (efficiency and concept of sealing between a movable door 2 and a fixed cabinet 3 ) also previously explained are fully met through the gasket 6 , herein referred to as the optional construction.
Having described examples of embodiment (preferable and optional), it should be understood that the scope of the present invention encompasses other possible variations, being limited just by the wording of the claims, including therein the possible equivalents thereof. | The present invention discloses a sealing system for a refrigerator and, more particularly, a sealing system located between the doors of a refrigerator and its acclimatized chambers and of the kind that comprises a gasket to be inserted in a receiving channel existing also between the doors of a refrigerator and its acclimatized chambers. The sealing system for refrigerator herein reported consists of at least one gasket comprising a tubular body formed by at least one attaching end and by at least one sealing body; at least one groove defined in at least one movable door or at least one fixed cabinet; and by at least one rib defined in at least one movable door or at least one fixed cabinet. | 5 |
BACKGROUND OF THE INVENTION
The invention herein described was made in the course of or under a contract or subcontract thereunder with the United States Air Force.
Control systems are known in which a hydraulic servo actuator is powered with a servo pump. In a typical system of this type, the actuator may include a pressure responsive member in the form of a piston and the servo pump may be of the swash-plate type. The servo pump controls the position of the piston by pumping fluid from one side of the piston to the other.
Control systems of this type exhibit many desirable characteristics. Unfortunately, however, the servo pump has low gain at and near null. This results in poor stiffness of the system at and near null. In other words, a given change in the input signal to the control system at or near null will not produce as large, or as predictable, a change in flow rate to the actuator as a corresponding signal change well away from null.
Null is a steady state condition of the actuator in which there is substantially no flow to or from the actuator. The input signal is representative of the desired change in position of the piston. For example, the input signal may be the sum of a command signal which represents a position in which the piston should be and a feedback signal which represents the actual instantaneous position of the piston.
SUMMARY OF THE INVENTION
The present invention provides a control system which has good stiffness throughout its full range of operation. This is accomplished by using multiple sources to power the actuator. A first of these sources provides good stiffness for a first range of values of the input signal and a relatively poor stiffness for a second range of values of the input signal. A second of the sources provides good stiffness for the second range of values of the input signal and relatively poorer stiffness for the first range of values of the input signal. These sources are arranged in parallel with their outputs being summed to provide the control system with good stiffness characteristics throughout its full range of operation.
The first of these power sources may include a servo pump which operates by pumping fluid from one side of the pressure responsive member to the other. Although the servo pump provides the system with relatively poor stiffness characteristics at and near null, it provides good stiffness characteristics outside of this range.
The second of these sources may include a source of fluid under pressure and a valve for controlling the supply of fluid under pressure to the fluid responsive member and the return of fluid from the fluid responsive member. The valve provides a stiffness characteristic which is substantially superior (a matter of magnitude not direction) to the stiffness characteristic provided by the servo pump. Thus, the valve provides good stiffness at and near null and is limited, but by choice (for power limits) stiffness outside of this range. Accordingly, by arranging the valve and the servo pump in parallel and summing their outputs, the control system will exhibit good stiffness characteristics throughout its full range of operation.
Within reasonable limits, the relationships between the input signal and flow rate to the valve can be varied. However, at and near null, the valve should provide a flow rate to the actuator which varies in accordance with changes in the input signal and preferably this relationship is linear. Outside of this range, the valve preferably supplies fluid under pressure to the actuator at a substantially fixed rate which is the maximum flow rate through the valve.
The valve is sized and configured so that when the input signal reaches a predetermined value, the valve supplies fluid to the actuator at a substantially fixed rate. However, for input signal values above the predetermined value, the servo pump is capable of providing the necessary stiffness and response. Thus, the valve has basic control of the actuator for input signal values less than the predetermined value and for input signal values above predetermined value, the servo pump assumes basic control of the actuator.
It is known to use a four-way valve for controlling an actuator throughout the full range of operation. However, the valve has a high power loss, and therefore rejects heat to the fluid at higher flow rates. The present invention eliminates these disadvantages by limiting the flow rate through the valve to the flow rates required at the near null. By way of example, the flow rates through the valve can be limited to the flow rate commanded by an input signal which is 7-10 percent of the input signal at full load. This prevents high power loss through the valve and consequent heat rejection while fully compensating for the width of the deadband exhibited by the servo pump.
Fluid under pressure can be supplied to the valve by an auxiliary pump. The auxiliary pump is preferably a variable delivery, constant pressure pump such as a swash-plate pump. The auxiliary pump should be capable of providing, as a function of pressure, variable delivery rates on demand.
It is known to use an auxiliary pump such as a gear pump to provide makeup for leakage from the control system. However, the auxiliary pump of this invention is utilized to supply fluid under pressure to a four-way valve which in turn is used as one of multiple parallel sources for powering the actuator.
The actuator which is controlled by the dual parallel sources may be any fluid driven power source such as a balanced actuator, an unbalanced linear actuator, a rotary actuator, or a hydraulic motor. The term "actuator" as used herein means any and all of these devices.
The input signal controls both the servo pump and the valve. For example, an electro hydraulic valve may be responsive to the input signal to provide a fluid control signal which in turn controls the position of a control piston. The control piston can be mechanically linked to the swash plate of the servo pump and to the valve to simultaneously control both of them.
The servo pump may be located in a case which is filled with fluid pressure. Another feature of the invention is a case pressure regulator which communicates with the opposite sides of the fluid responsive member for controlling the pressure of the fluid in the case. The case pressure regulator may be used to establish various different relationships between case pressure and pressure in the actuator. Preferably, the case pressure regulator may maintain the pressure in the case approximately equal to the pressure on whichever side of the fluid responsive member has the lower pressure. This reduces leakage at the servo pump and therefore reduces makeup to the valve at null. The case pressure regulator also reduces heat rejection in that with less leakage, less flow to the valve and hence less heat rejection are obtained.
The invention, together with further features and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic view partially in section of a control system constructed in accordance with the teachings of this invention.
FIGS. 2 and 3 are plots of input signal versus flow rate for the servo pump and the valve, respectively.
FIG. 4 is a plot of input signal versus flow rate with the servo pump and valve outputs summed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a control system 11 which includes an actuator 13 which is usable to position a load such as a flight control surface 15 of an aircraft. Although the actuator 13 can be of various different kinds, in the embodiment illustrated, it includes a housing 17, a fluid responsive member in the form of a piston 19, and a connecting rod 21 suitably coupled to the piston 19 and the flight control surface 15 for positioning the latter. The piston 19 has opposite pressure responsive faces 23 and 25. The piston 19 divides the housing 17 into chambers 27 and 29 on opposite sides of the piston. The actuator 13 is a balanced actuator in that it has a rod 31 attached to the piston 19 opposite the connecting rod 21. In other words, the effective areas of the pressure responsive faces 23 and 25 are equal.
The piston 19 can be moved by a servo pump 33 and/or a four-way valve 35. The servo pump 33 communicates with the chamber 27 by way of a flow path comprising conduits 37 and 39. Similarly, the servo pump 33 communicates with the chamber 29 by way of a flow path comprising conduits 41 and 43. The servo pump 33 may be of any type which is capable of controlling the position of the piston 19 in the housing 17 by pumping fluid between the chambers 27 and 29. In the embodiment illustrated, the servo pump 33 is in the form of a swash-plate pump, and it includes a swash plate 45 suitably mounted for pivotal movement about a pivot axis 47.
With the swash plate 45 at a neutral or null position, the pump delivery is zero. With the swash plate 45 tilted to one side of null, the pump 33 draws fluid from the conduit 37 and discharges it into the conduit 41, and with the swash plate 45 tilted on the other side of neutral, the pump draws fluid from the conduit 41 and delivers it into the conduit 37. The flow rate of the fluid discharged by the pump 33 is controlled by the angle of the swash plate 45. Servo pumps of this type are conventional. The pump 33 can be driven by a motor such as an electric motor 49.
The valve 35 in the embodiment illustrated is a spool valve and includes a valve housing 51 and a spool 53 slidable in a passage 54 in the housing. The valve housing 51 has a supply port 55, a pair of return ports 57 and 59, and actuator ports 61 an 63, each of which communicates with the passage 54.
The spool 53 has control lands 65 and 67 and end lands 69 and 71 which block off the opposite ends of the passage 54 in the valve housing 51. In the position shown in FIG. 1, the spool 53 is at null in which the lands 65 and 67 close or substantially close the actuator ports 61 and 63.
The port 61 communicates with the chamber 27 through a conduit 73 and the port 63 communicates with the chamber 29 through a conduit 75. The valve 35 is supplied with fluid under pressure from a suitable source of fluid under pressure such as an auxiliary pump 77 having a housing 78 via a supply conduit 79. Fluid is conducted to a reservoir 80 in the housing 78 by the ports 57 and a low pressure return conduit 81.
Fluid under pressure can be supplied to the valve 35 through the conduit 79 by any device which is capable of providing variable quantities of fluid at substantially constant pressure. Thus, although other devices could be used, in the embodiment illustrated this function is carried out by the auxiliary pump 77 which is a fixed displacement constant pressure pump of the swash plate type. The pump 77 includes a swash plate 83 which is driven by the motor 49. Although variable delivery can be provided in different ways, in the embodiment illustrated, it is accomplished by throttling the inlet of the pump 77. Pumps of this type are conventional.
Both the servo pump 33 and the valve 35 are controlled by an electro hydraulic valve 85. The electro hydraulic valve 85 receives an electrical input signal at terminals 87 and in response thereto provides a fluid output signal in a well-known manner. Specifically, the valve 85 receives fluid from the conduit 79 via a conduit 89. The valve 85 divides the flow from the conduit 89 in accordance with the input signal between conduits 91 and 93 with the excess fluid flowing through a conduit 95 to a case 97 for the servo pump 33. Electro hydraulic valves of this type are conventional.
The conduits 91 and 93 lead to the opposite sides of a control piston 99 which is mounted for movement in a passage 101 of a housing 103. Thus, the electro hydraulic valve 85 responds to the input signal 87 by controlling the position of the piston 99 in the passage 101.
The movement of the piston 99 can be used in a variety of ways to control the output of the servo pump 33 and the output of the valve 35. In the embodiment illustrated, mechanical linkages are utilized to permit the control piston 99 to change the angle of the swash plate 45 and to move the spool 53 axially relative to the housing 51. Specifically, the mechanical linkages includes a connecting rod 105 coupled to the piston 99 and a pair of links 107 and 109 pivotally joined to each other and to the connecting rod and the swash plate 45, respectively. The mechanical linkage for controlling the spool 53 includes a connecting rod 111 joined to the piston 99 and a link 113 pivotally connected to the outer end of the connecting rod. A bell crank 115 is pivotally mounted to any fixed structure such as the valve housing 51. Opposite ends of the bell crank 115 are pivotally connected to the link 113 and one end of the spool 53, respectively.
The case 97 and the valve housing 51 are maintained in fluid communication by a linkage housing 117 which contains the link 113. The present invention includes a case pressure regulator 119 for controlling the pressure in the case 97 and the housings 51 and 117.
The case pressure regulator 119 includes a housing 121 having parallel passages 123 and 125 extending therethrough. One end of each of the passages 123 and 125 is in communication with the interior of the case 97 via a conduit 127. The other ends of the passages 123 and 125 communicate with the conduits 43 and 39, respectively, via conduits 129 and 131. Intermediate regions of the passages 123 and 125 are in communication with a return conduit 133 which passages through a cooler 135 and extends to the reservoir 80.
Pistons 137 and 139 are mounted for sliding movement in the passages 123 and 139, respectively. In the positions shown in FIG. 1, the pistons 137 and 139 block ports 141 and 143, respectively, leading to the conduit 133. Identical springs 145 and 147 urge the pistons 137 and 139, respectively, to the left as viewed in FIG. 1.
The piston 137 will assume a position in the passage 123 which is dependent upon the relative pressures in the conduits 127 and 129 and the strength of the spring 145. Similarly, the piston 139 will assume a position in the passage 125 which is dependent upon the relative pressures in the conduits 127 and 131 and the strength of the spring 147. In this manner, the maximum pressure in the case 97 and hence in the housings 51 and 117 can be limited to some function of the pressure in the chamber 27 or the chamber 29, whichever is lesser.
If the opposite pressure responsive faces of the pistons 137 and 139 are of approximately equal area and if the springs 145 and 147 are very light, then the maximum pressure in the case 97 cannot exceed the pressure in the chamber 27 or the pressure in the chamber 29, whichever is lower. For example, if the pressure in the chamber 27 is less than in the chamber 29, then this pressure acts on the right face of the piston 139. If the pressure in the case 97 increases slightly above this level, it will be able to force the piston 139 to the right against the biasing action of the light spring 147 to open the port 143 whereby a flow path from the case 97 to the low pressure return conduit 133 is established. If the pressure in the chamber 29 is lower than in the chamber 27, then the pressure in the conduit 127 moves the piston 137 to open the port 141 to establish communication between the case 97 and the return conduit 133.
In operation of the control system 11, the motor 49 drives the servo pump 33 and the auxiliary pump 77. In response to an input signal at the terminals 87, the electro hydraulic valve 85 divides the flow from the conduit 89 between the conduits 91 and 93 to position the control piston 99. This sets the angle of the swash plate 45 and the position of the spool 53 in accordance with the input signal.
Assuming that the input signal calls for movement of the piston 19 of the actuator 13 to the right as viewed in FIG. 1, the servo pump 33 pumps fluid from the chamber 29 through the conduits 43, 41, 37, and 39 to the chamber 27. In addition, the spool 53 is moved to the left from the position shown in FIG. 1 so that the lands 65 and 67 uncover the ports 61 and 63, respectively. The auxiliary pump 77 pumps fluid from the reservoir 80 through the supply conduit 79, the supply port 55, the actuator port 61, and the conduit 73 to the chamber 27. In addition, fluid can flow through the actuator conduit 75, the actuator port 63, the return port 59, and the return conduit 81 to return, i.e. to the reservoir 80 of the auxiliary pump.
To move the piston 19 to the left, the action described above for the servo pump 33 and the valve 35 is reversed. To maintain the piston 19 in position, both the swash plate 45 and the spool 53 are maintained at null, and there is substantially no flow to and from the actuator 13.
With the arrangement shown in FIG. 1, the servo pump 33 and the valve 35 are in parallel and the flows from these devices sum at the actuator 13. Of course, the flows can be summed at any location so long as the actuator 13 receives the sum of the flows.
Case pressure acts at the axial outer ends of the end lands 69 and 71 and exists in the housing 51 and 117 and in the case 97. The case pressure regulator 119 operates as described above to maintain the pressure within the case 97 and the housings 51 and 117 no greater than about the pressure in the chambers 27 and 29, whichever is lower. Of course, by changing the relative areas of the pressure responsive faces of the pistons 137 and 139 and/or the strength of the springs 145 and 147, the maximum pressure limit in the case 97 and the housings 51 and 117 can be set at a new value.
The concepts of the present invention can be further understood with reference to FIGS. 2-4. FIG. 2 is a plot of input signal I versus flow rate Q from the servo pump 33 with only the servo pump operating and with the valve 35 eliminated from the system. The input signal represents the difference between a command signal which represents the desired position of the piston 19 and a feedback signal indicating the actual position of the piston 19.
FIG. 2 shows that for a range of input signals having a value of ± x there is substantially no flow produced by the servo pump 33. In other words for the input signal range of ± x, the servo pump exhibits a deadband characteristic which produces poor response and a loss of stiffness. Characteristically, the signal range ± x is in the order of ± 7-10 percent of the input signal at full load. In the input signal range of ± x, the flow is substantially zero, and a curve segment 151 represents substantially zero flow. For signal values greater than ± x, the delivery rate of the servo pump 33 varies substantially linearly with the magnitude of the input signal, and this is illustrated by curve segments 153 and 155.
FIG. 3 is a plot similar to FIG. 2 but with only the valve 35 operating and with the servo pump 33 out of the system. The flow rate characteristic for the valve 35 is substantially opposite that of the servo pump 33 in that for a signal range of ± x the relationship between input signal and flow rate is substantially linear as shown by curve segment 157. Conversely, for input signals outside the range of ± x, the valve 35 supplies fluid at a substantially fixed rate as indicated by curve segments 159 and 161. In other words, the valve 35 is wide open for signal values of ± x, and therefore cannot provide an increase in flow rate in response to increases in the magnitude of the input signal.
FIG. 4 shows a curve 163 which represents the flow to the actuator 13 when both the servo pump 33 and the valve 35 are used. In other words, the curve 163 represents a summation of the flows depicted graphically in FIGS. 2 and 3. The curve 163 is substantially linear throughout the full range of operation of the control system 11. In order to accomplish this, the slopes of the curve segments 153, 155, and 157 must be substantially parallel and the ± x signal values for the servo pump (FIG. 2) and for the valve 35 (FIG. 3) must be approximately the same. In other words, when the input signal reaches a value of slightly greater than ± x, the servo pump 33 begins delivering fluid in accordance with the curve segment 153 and the valve 35 delivers fluid in accordance with the curve segment 159.
Although an exemplary embodiment of the invention has been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention. | A control system comprising an actuator having a fluid responsive member movable in at least first and second directions and two sources for controlling the fluid responsive member. A first of these sources includes a servo pump which pumps fluid from one side of the fluid responsive member to the other to thereby control the position of the fluid responsive member. A second of these sources includes a valve which controls the supply of fluid under pressure to the fluid responsive member and the return of fluid from the fluid responsive member. The servo pump and valve are arranged in parallel with their flows being summed at the actuator. | 5 |
FIELD OF THE INVENTION
This invention is directed to the separation of gas bubbles from flowing liquid systems, particularly cardio-pulmonary bypass circuits employed during open-heart operations to separate air emboli from the flowing blood.
BACKGROUND OF THE INVENTION
In hydraulic circuits which contain moving fluids, it is frequently necessary to eliminate gas bubbles before they reach functional parts. A specialized example of such a circuit is a cardio-pulmonary bypass circuit employed during open-heart procedures. If blood in such a circuit contains air or gas emboli, it is imperative to remove such emboli (i.e. bubbles) before they reach the patient. Otherwise, the emboli may cause serious neurological damage or death. Blood-separating devices in cardio-pulmonary circuits are usually placed between the arterial pump and the patient so that air emboli are removed before the blood reaches the patient. Many surgical teams use arterial filters to serve as a bubble trap. The filter does not allow bubbles to pass through the tiny filter openings. The problem is that the openings must be very small to be effective bubble stops, and such small openings may cause harm to the delicate red blood cells. There is, thus, a need for a phase-separating device which passes blood atraumatically and separates air. The air may be separated and returned to the oxygenator to recover any physiological liquids delivered therewith. Similar problems exist with other physiological fluids which may be found in the operating field.
There are several bubble traps presently available. One has a large internal volume, and thus wastes a great deal of blood, and it has to be disassembled and cleaned after every operation because it is not a disposable device. Another device is made from polymer composition material and is pre-sterilized and disposable. This device separates bubbles from the blood by relying on circular flow, but the problem is that there are internal flow-directing vanes which present a large surface area. The edges of the vanes may cause trauma to red blood cells as they impinge upon the vanes during flow. Furthermore, the large surface area may be harmful because it is known that any surface contact with blood may cause platelet damage. Thus, it is desirable to minimize the surface area in contact with the flowing blood.
Another commercially available separator is made of polymer material and is disposable. It relies on circular flow, and to achieve this flow, the blood inlet fitting is tangentially directed. The inlet is a side fitting positioned in the horizontal plane, and the attachment of tubing thereto becomes difficult because in normal circumstances, the tubing will hang and may pinch. The tubing does not drape naturally from such a side fitting.
Examples of two prior bubble trap structures are found in George G. Siposs U.S. Pat. Nos. 4,344,777 and 4,368,118.
There is need for a simple, disposable device which can be inexpensively produced and pre-sterilized. Such a device needs to separate gas bubbles from a moving stream of physiological liquid, such as blood, without being unnecessarily complex. Furthermore, the device must have a minimum blood contact surface and must have no structure inside the device with which the flowing liquid would be in contact which could cause trauma to the delicate blood cells. In addition, the device must have a minimum interior volume to minimize blood loss. Also, the device must have a minimum number of easy-to-produce parts to be trouble-free and inexpensive.
SUMMARY OF THE INVENTION
In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a bubble trap for phase-separating gas bubbles from flowing liquids, particularly physiological liquids, and comprises a body with a circular section. The side of the circular body has a side arm thereon with an upwardly directed inlet. The side arm is tangentially connected to the body so that upwardly moving mixed liquid turns and causes horizontal rotation of the mixed liquid within the body. This rotation encourages separation of gas and air bubbles from the liquid. The body has a downwardly directed bottom outlet for the liquid. In another embodiment, the body contains therein a filter which filters large solids from the blood. In such a case, the outlet is at the bottom of the body and receives flow from the interior of the filter.
It is thus an object and advantage of this invention to provide a bubble trap for phase-separating gas bubbles from flowing liquids, and particularly physiological liquids wherein the bubble trap has a hollow body of minimum size, minimum contact area, and is tangentially supplied with in-flowing liquid so that rotation of the liquid within the body causes bubble separation.
It is another object and advantage of this invention to provide a bubble trap which has vertical inlet and outlet fittings so as to allow the connected fluid filled lines to drape naturally and provide a body which has a circular shape and a tangential flow near the top, to cause rotation within the body without the need for flow-directing vanes.
It is a further object and advantage of this invention to provide a bubble trap which is structured by combining basic geometric shapes so that the resulting structure can be readily molded and easily assembled, so that it may be economically supplied for wide use, can be easily sterilized, and provides disposability.
Other purposes and advantages of this invention will become apparent from a study of the following portion of the specification, the claims and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the first preferred embodiment of the bubble trap of this invention.
FIG. 2 is a bottom view thereof.
FIG. 3 is a central section through the bubble trap of FIG. 1 showing an optional filter therein.
FIG. 4 is an upward view under the cap of the bubble filter of FIG. 3, as seen generally along the line 4--4 of FIG. 3.
FIG. 5 is a view similar to FIG. 3 showing the bubble trap without the filter.
FIG. 6 is an enlarged similar view of the bubble trap, showing a space filler therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1, 2 and 3 show various views of the first preferred embodiment of the bubble trap of this invention for phase separating gas bubbles from flowing liquids. The bubble trap is generally indicated at 10 in these FIGURES. The bubble trap is made of two parts of injection-molded polymer composition material which are secured together. They are preferably made of clear, medical grade polycarbonate and are ultrasonically welded together to form the bubble trap 10. The two principal parts are body 12 and cover 14. Body 12 is principally a hollow housing 16 which is curved around the central axis 18 of the bubble trap 10. This central axis is normal to the sheet of drawing in FIGS. 1 and 2 and lies upright in the sheet in FIG. 3. Housing 16 is preferably substantially a circular cylindrical tube, but has some taper or draft to it in order to permit convenient molding. Towards the bottom of housing 16, step 20 is formed therein as a shape of revolution around the axis. Below step 20, floor 22 is substantially flat and sloped with respect to the axis. At the lowest point of the floor, barbed outlet tubular fitting 24 is provided. Outlet fitting 24 is off center from the axis and is downwardly directed parallel to the axis. The offset outlet eliminates the vortex which occurs with a center outlet. The vortex would suck in air bubbles to defeat the separation produced by the trap.
Center cone 26 is a hollow cone mounted on floor 22 and extending upwardly within the open interior of the housing. The purpose of the center cone is to reduce interior volume of the housing, and to provide a support for a filter. It also eliminates vortexing. Filter 32 is a conical accordion-pleated filter of woven synthetic polymer composition mesh or stainless steel wire mesh. The preferred mesh is a polyester monofilament woven screen having openings in the range of 20 to 60 microns and having a filament diameter in the 20 to 60 micron range. The filter fabric is described in more detail in George G. Siposs U.S. Pat. No. 4,344,777, the disclosure of which is incorporated herein by this reference. The filter must have sufficiently large mesh so as to pass blood cells with minimum trauma thereto, to hold back blood clots, and should hold back air or gas bubbles. Filter cover 34 closes the top of the filter, holds the filter in place, and engages upon the top of center cone 26 to firmly retain the filter in place.
The filter medium is preferably a polyester screen with uniform interstices of about 40 microns. The filter screen has about 25 percent open area. In order to support the polyester screen filter medium, polypropylene mesh of more coarse weave is used on each side of the filter mesh as support. This three-layer sandwich is pleated and configured in the truncated conical configuration and is potted between two end plates. The lower end plate 28 has an opening 30 therein which surrounds the center cone 26 and provides for downward outflow from the interior of the filter. Filter cover 34 is potted to the top of the filter fabric and may have a dimple therein to receive the top of the center cone to stabilize the filter. The bottom end plate 28 rests against the step 20 and is bonded thereto to secure the filter in place. The center cone thus also acts as a stabilizer for the filter to prevent accidental dislodgement during shipping and other vibrational stress.
The top of housing 16 terminates in flange 36, which has a side arm surface thereon extending away from the side of housing 16. Upwardly directed inlet fitting 38 is a barbed tubular inlet fitting similar to and lying parallel to outlet fitting 24. The inlet passageway 40 extends up through the inlet fitting and through the corresponding opening in the flange.
Cover 14 is also an injection-molded part of the same material. It has a flange 42 which overlies and is secured to flange 36, e.g. by ultrasonic welding as previously described. Cover 14 includes a cap 44 which overlies the housing 16. Cap 44 has an interior space which joins the interior space of the housing 16 to define the interior volume of the bubble trap. The interior space of cap 44 terminates in upwardly directed cone 46. Gas vent fitting 48 is at the top of the cap, on the center line, at the top of the cone. The gas vent fitting may be a Luer fitting and preferably is connected to a purge line with a check valve therein to prevent inflow of gas through the vent fitting into the body. Boss 50 is formed on the top of flange 42 and extends from inlet passage 40 to cap 44. It defines inlet passage 52 which joins the inlet passage 40 with the space under the cap. As is seen in FIGS. 1 and 4, the inlet passage 52 enters the cap in a direction so that it is tangential with the circular space defined under the cap.
The bubble trap 10 is preferably used in the arterial blood flow circuit, and the blood enters the trap through the vertically oriented inlet fitting 38 which has a conventional barbed configuration. The transition from the inlet passage 40 to the inlet passage 52 is with a smooth curve so that the inflowing blood turns into a horizontal direction and flows through the straight inlet passage 52 to the circular debubbling chamber 54 defined within cap 44 in housing 16. The tangential entry of the blood into the debubbling chamber 54 causes gentle rotation of the blood. This rotation causes the relatively lighter gas bubbles to congregate in the center of the chamber, with the upper portion of the chamber within the cover. The collected gas bubbles coalesce, rise and exit out of the gas vent fitting 48. The rotating blood gently descends into the lower part of the chamber which contains the filter. The blood flows through the filter and exits the housing through the vertically directed downward outlet fitting 24, which is also of barbed configuration so that conventional flexible tubing can be quickly installed on both the inlet and outlet fittings.
The circular debubbling chamber is above the filter element so that bubbles are separated from the blood and are removed through the vent before they come into contact with the filter element. In addition, wetted filters resist the passage of gas bubbles passing therethrough. This is because the surface tension of the blood covering the filter openings is quite strong and it would require a considerable trans-filter pressure differential to force the bubbles through the filter cloth. Thus, the filter serves as a backup protection against the transmittal of gas bubbles.
FIG. 5 shows bubble trap 60 as being formed of body 62 and cover 64. The body 62 and cover 64 are respectively identical to body 12 and cover 14 of the bubble trap 10. The difference is that bubble trap 60 does not have therein a filter to remove particles from the blood. Bubble trap 60 has the upwardly directed inlet fitting 66 which introduces inflowing liquid to tangential inlet passage 68 which tangentially introduces the liquid into the debubbling chamber 70. The general circular motion in the debubbling chamber causes the small gas bubbles to join and combine and rise to be exhausted out of vent fitting 72, which is at the top of the debubbling chamber under the conical cover where the gas bubbles concentrate. The down-flowing liquid passes down and out of outlet fitting 74, which is barbed like the inlet fittings 66 to be connectable to standard flexible tubing. The center cone 76 reduces the volume of the debubbling chamber and inhibits vortexing by occupying the center and placement of the outlet fitting towards the circumferential edge of the debubbling chamber. Thus, the bubble trap 60 is identical to the bubble trap 10, except for the absence of the filter in bubble trap 60. Either of these bubble traps can be made smaller for pediatric service because of the lower flow rates in pediatric service.
Bubble trap 80, shown in FIG. 6, has an identical body and cover to those shown with respect to bubble traps 10 and 60 in FIGS. 1 and 5. Body 82 has the same interior debubbling chamber, interior cone 84 and off-center outlet fitting 86. Its cover 88 has the same uprightly directed inlet fitting 90 beside the debubbling chamber 92. Tangential inlet passage 94 tangentially directs the incoming liquid to the debubbling chamber. In the case of bubble trap 80, outlet check valve 96 is shown as mounted on vent fitting 98. When the vent fitting is of standard Luer configuration, Luer nut 100 is detachably attached thereto. Flexible tube 102 connects the nut with the outlet check valve 96 so that inflow of gas into the bubble trap is prevented. Such a structure can also be applied to the bubble traps 10 and 60. On the other hand, instead of venting to atmosphere, the flexible vent line 102 can be exhausted to a reservoir such as a cardiometry reservoir or oxygenator as long as it has a lower internal pressure than the bubble trap.
To reduce the interior volume of the bubble trap 80, the interior volume of the debubbling chamber can be reduced by the installation of filler 104. This is particularly useful in pediatric cases where the flow rate is lower and low priming volume is imperative. Filler 104 is comprised of upper and lower cases, interengaged together along their parting line and sealed together with appropriate means such as ultrasonic welding. The upper cup embraces the tip of cone 84, and the lower cup tightly embraces the base of the cone, above the floor 106 of body 82. The upper portion of the debubbling chamber remains at the same volume so that debubbling is properly achieved. Liquid velocity in the space between the filler and the outer wall of the body is no higher than that in an adult-sized unit operating at normal adult flow rates. Thus, no reduction in efficiency occurs, but blood volume is conserved.
The body of each bubble trap is sufficiently strong so that a clamp on the mast of cardio-pulmonary equipment can engage thereon so as to support the bubble trap in the upright position, permit the inlet and outlet arterial tubes to drape naturally, and keep rotation horizontal.
This invention has been described in its presently contemplated best modes, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims: | Bubble trap has a hollow body with an upwardly directed mixed fluid inlet on its side directed to introduce mixed fluid in a tangential direction so as to rotate the liquid within the body. This rotation permits separation of the gas bubbles from the liquid and permits withdrawal of the debubbled liquid from the bottom of the body. The inlet and outlet from the body are respectively upwardly and downwardly directed to permit draping of inlet and outlet hoses. In one embodiment, a filter is installed to facilitate gas bubble separation. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an amplifier and, more particularly, to an amplifier for controlling linear gain of wide band using external bias which controls the amplification gain at high frequencies of a wide band input signal and has good linear gain characteristics for high-frequency and large-input signal by adjusting an external bias.
In image processing systems such as video tape recorders and televisions, differential amplifiers as shown in FIG. 1A and 1B are normally employed to amplify high-frequency image signals. In these amplifiers two identical transistors Q1 and Q2 are symmetrically composed between positive and negative supply voltages V cc and -V EE and common emitter current IEE is a constant current source. Collector resistors R c 'S of the transistors Q1 and Q2 are identical with each other, and emitter resistors R e are also identical with each other. Then, an input signal Vin applied to the base of the transistor Q1 is amplified and provided through the collector resistors Rc as an output voltage V c .
On the other hand, the gain of the amplifier shown in FIG. 1A is determined as follows. Applying the Kirchhoff's voltage law to a loop including the base-emitter junctions of the transistors Q1 and Q2, the following equation is satisfied,
V.sub.in =V.sub.BE1 -V.sub.BE2 ( 1)
where, V BE2 , and V BE2 are the base-emitter voltage drops of the transistors Q1 and Q2, respectively.
Eq.(1) can also be rewritten as follows, using the relationship I c =I s ##EQU1## where, V T (=kT/q) is the thermal voltage and has a value of about 26 mV at 300° K, I s is the reverse saturation current and has a value of about 2×10 nA/cm 2 at 300° K, and I c1 and I c2 are the collector currents of the transistors Q1 and Q2.
Assuming that the transistors Q1 and Q2 are identical with each other, i.e., I s1 =I s2 , then Eqs.(1) or (2) can be rewritten as, ##EQU2## Also, the following relation is satisfied,
I.sub.c1 =I.sub.c2 =αF.I.sub.EE ( 4)
where, αF is the current amplification ratio in common-base configuration and has a value of almost 1.
Thus, the collector currents I c1 and I c2 are given from Eqs. (3) and (4), by ##EQU3##
On the other hand, the output voltage V o1 from the transistor Q1 and the output voltage V o2 from the transistor Q2 are given by, respectively,
V.sub.o1 =V.sub.cc -I.sub.c1 ·R.sub.c ( 7)
V.sub.o2 =V.sub.cc -I.sub.c2 ·R.sub.c ( 8)
Then, the final differential output voltage V o becomes, ##EQU4##
As expressed in Eq.(10), when the input voltage V in is larger than V T , a large distortion is produced due to hyperbolic tangent characteristics and thereby the circuit shown in FIG. 1A is no longer used as an amplifier.
In order to compensate the distortion, resistors R e are appended to both emitters of the transistors Q1 and Q2. Then, the linearity is improved, but in has still another problem that the voltage gain is reduced.
SUMMARY OF THE INVENTION
The present invention solves these problems and provides an amplifier for controlling linear gain of wide band which amplifies a high-frequency and large-input wide band signal without distortion, by using external bias.
Further, the present invention provides an amplifier for controlling linear gain of wide band which is able to control the amplification gain of the high-frequency input signal by external bias adjustment.
Further more, the present invention provides an amplifier for controlling linear gain of wide band which is able to maintain stable gain characteristics even at high-frequency range by external bias adjustment.
According to the present invention, there is provided an amplifier for controlling linear gain of wide band including an amplifier for high-frequency application, comprising a first voltage generator for generating a first fine voltage with the inverse hyperbolic tangent function of an external bias voltage, a first voltage-to-current converter for generating a first current which is the hyperbolic tangent function of the first fine voltage, thereby being proportional linearly to the external bias, a second voltage generator for generating a second fine voltage with the inverse hyperbolic tangent function of an input signal, a second voltage-to-current converter for controlling the first current by generating a second current which is the hyperbolic tangent function of the second fine voltage, thereby being proportional linearly to the input signal, and a current-to-voltage converter for converting the first current to a linear output voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show conventional amplifier circuits.
FIG. 2 is a block diagram of an amplifier according to the present invention, and
FIG. 3 is a detailed circuit of a preferred embodiment of the amplifier in FIG. 2 according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be now described in more detail with reference to accompanying drawings. FIG. 2 shows the block diagram of an amplifier according to the present invention, which comprises a first voltage generator 10 for producing a first fine voltage ΔV 1 with the inverse hyperbolic tangent (tanh -1 ) function of an external bias voltage V B for gain compensation, a first voltage-to-current (V/I) converter 20 connected to the first voltage generator 10 for generating a first current I1 with the hyperbolic tangent function (tanh) of the first fine voltage, thereby being proportional linearly to the external bias voltage V B , a second voltage generator 30 for producing a second fine voltage ΔV 2 with the inverse hyperbolic tangent function of an input voltage V in , a second voltage-to-current converter 40 connected to the second voltage generator 30 for generating a second current I2 with the hyperbolic tangent function of the second fine voltage ΔV 2 , thereby being proportional linearly to the input voltage V in , and a current-to-voltage (I/V) converter 50 connected to the first voltage-to-current converter 20 for converting the first current I.sub. 1 to a linear output voltage V o .
The first voltage generator 10 receives the external bias voltage V B for controlling amplification gain and generates the first fine voltage ΔV 1 with the inverse hyperbolic tangent function of V B . Since the external bias voltage V B is a DC voltage having a predetermined variable range, the first fine voltage ΔV 1 does not exceed 1V.
The first voltage-to-current converter 20 converts the first fine voltage ΔV 1 to the first current I 1 with the hyperbolic tangent function of ΔV 1 . Thus, the first current I 1 is proportional linearly to the external bias voltage V B .
On the other hand, the second voltage generator 30 receives the high-frequency input signal V in and generates the second fine voltage ΔV 2 with the inverse hyperbolic tangent function of V in . The second fine voltage ΔV 2 is proportional to the input voltage V in , but does not exceed 1V, similar to the first fine voltage ΔV1.
The second voltage-to-current converter 40 converts the second fine voltage ΔV 2 to the second current I 2 with the hyperbolic tangent function of ΔV 2 . Thus, the second current is proportional linearly to the input voltage V in . Also, if the second current I2 is varied, the external bias voltage V B is varied and thereby the first current I 1 is also varied. Thus, the first and second currents I 1 and I 2 are dependent linearly on each other.
As described above, the first current I 1 is adjusted by the external bias voltage V B and proportional linearly to the second current I2, and converted to the output voltage V o by the current-to-voltage converter 50. The output voltage V o is also proportional linearly to the first current I 1 . Accordingly, a desired gain is achieved by adjusting the external bias voltage V B ; and the linearity of the amplifier is maintained stably regardless of the magnitude of the high-frequency input signal V in .
FIG. 3 is the detailed circuit showing the embodiment of FIG. 2 according to the present invention, which comprises first and second voltage generators 10 and 30, first and second voltage-to-current converters 20 and 40, and a current-to-voltage converter 50, identical to the configuration in FIG. 2.
The first voltage generator 10 comprises transistors 11 and 12 of which emitters are symmetrically connected to each constant current source I o1 and bases are connected to an external bias voltages V B added to a first reference voltage V ref1 and a second reference voltage V ref2 , respectively, resistor 13 connected between the emitters of the transistors 11 and 12, and diodes 14 and 15 of which cathodes are respectively connected to the collectors of the transistors 11 and 12 and anodes are connected in common to a supply voltage V cc .
The first voltage-to-current converter 20 comprises transistors 21 and 22 connected between the supply voltage V cc and to each constant current source I o2 for buffering the input signals applied to each base from the collectors of the transistors 11 and 12, and emitter-coupled transistors 23 and 24 for receiving the output voltages from the emitter nodes of the transistors 21 and 22 as differential input signals.
The second voltage generator 30 comprises transistors 31 and 32 of which emitters are symmetrically connected to each constant current source I o1 and bases are respectively connected to an input voltages V in added to a third reference voltage V ref3 and a fourth reference voltage V ref4 , a resistor 33 connected between the emitters of the transistors 31 and 32, and diodes 34 and 35 of which cathodes are respectively connected to the collectors of the transistors 31 and 32 and bases are connected to each other, and a transistor 36 of which a base is connected to a fifth reference voltage V ref5 for providing a desired voltage to the common anode node of the diodes 34 and 35 by a constant voltage dropped from the supply voltage V cc .
The second voltage-to-current converter 40 comprises transistors 41 and 42 connected between the supply voltage V cc and each constant current source I o2 for buffering the input signals applied to each base from the collectors of the transistors 31 and 32, and transistors 43 and 44 of which bases are respectively connected to the emitters of the transistors 41 and 42 and emitters are connected in common to a constant current source I BB . The collector of the transistor 43 is connected to the common-emitter node of the transistors 23 and 24, while that of the transistor 44 is connected to the supply voltage V cc .
The current-to-voltage converter 50 comprises only a resistor connected between the supply voltage V cc and the collector of the transistor 24. All of the transistors in FIG. 3 are NPN type. Also, all of the diodes in FIG. 3 are formed by using NPN transistors, i.e., the base of the NPN transistor is used as the anode, and the collector and emitter are tied to be used as the cathode.
Now, the operation of the embodiment according to the present invention shown in FIG. 3, is described in more detail.
The input-to-output voltage gain V o /V in is determined by the following sequence.
Neglecting the base currents of the transistors 31 and 32, first, their collector currents become, respectively,
i.sub.c1 =I.sub.o1 +i.sub.x1 (11)
i.sub.c2 =I.sub.o1 -i.sub.x1 (12)
where, i c1 , i c2 , I o1 , and i x1 are the collector current of the transistor 31, the collector current of the transistor 32, the constant current source, and the current flowing through the resistor 33 connected between the emitters of the transistors 31 and 32, respectively.
Applying the kirchhoff's second law (voltage law) to a loop including the base-emitter junctions of the transistors 31 and 32, the input voltage V in is expressed as,
V.sub.in =V.sub.BB1 -V.sub.BB2 +i.sub.x1 ·R.sub.x (13)
where, V BB1 and V BB2 are the base-emitter voltages of the transistors 31 and 32, respectively, and R x is the value of the resistor 33 connected between the emitters of the transistors 31 and 32.
Eq.(14) can be rewritten as, ##EQU5## where, V T is the thermal voltage and I s1 and I s2 are the reverse saturation currents of the transistors 31 and 32, respectively, as explained in Eq. (2).
If the transistors 31 and 32 are identical with each other, i.e., the base doping density and the geometrical size are the same, then Is1 is equal to Is2 and thus Eq. (14) can be reduced to, ##EQU6##
Dividing both sides of Eq. (15) by R x and substituting Eq.(11) and (12), one obtains, ##EQU7##
If the first term on the right side of Eq. (16) becomes zero, V in is dependent linearly on i x1 .
Differentiating the first term of Eq. (16) with respect to i x1 , in order to identify this substantially, the following equation is satisfied, ##EQU8## where, r e is the small-signal dynamic resistance at the emitter node of the transistor.
If R x > r e1 +r e2 , then, Eq. (16) satisfies the linear relationship, i.e., V in is dependent linearly on i x1 . Thus, Eq. (11) and (12) can be simplified to, ##EQU9##
Since i c1 and i c2 are different from each other as shown in Egs. (18) and (19), voltage drops across the diodes 34 and 35 are also different from each other. This difference between the diode voltage drops is applied between the bases of the transistors 43 and 44. Applying the Kirchhoff's second law, the following equation is satisfied,
ΔV.sub.z =V.sub.BE3 -V.sub.BE4 (20)
where, V BE1 and V BE2 are the voltage drops across the diodes 34 and 35, respectively, and V 2 is the second fine voltage. Therefore, Eq. (20) can be rewritten as, ##EQU10## where, I s3 and I s4 are the reverse saturation current of the diodes 34 and 35, respectively, as described in Eq. (2).
Assuming that the diodes 34 and 35 are identical with each other, i.e., I s3 =I s4 , Eq. (21) is reduced to, ##EQU11##
Using the relationship ##EQU12##
Eq. (22) can be written as, ##EQU13##
Thus, the voltage drop difference between the diodes 34 and 35 is the inverse hyperbolic tangent function of the input voltage. The voltage drop difference, i.e., the second fine voltage ΔV 2 is buffered by the transistors 41 and 42 and next applied between the transistors 43 and 44, thereby determining their collector currents i c4 and i c3 .
Thus, the second fine voltage ΔV 2 can be rewritten as, ##EQU14## where, V BE5 and V BE6 are the base-emitter voltage of the transistors 44 and 43.
Assuming that the transistors 43 and 44 are identical with each other. Eq. (25) becomes, ##EQU15## also, the following relation is satisfied,
i.sub.c3 +i.sub.c4 =αF·I.sub.EE (28)
where, I EE is the constant current and αF is almost 1.
Thus, Eq. (28) is reduced to,
i.sub.c3 +i.sub.c4 =I.sub.EE (29)
From Eq. (27) and (29), the collector currents of the transistors 44 and 43 are given by, respectively, ##EQU16##
Then, the collector current difference ΔI c is given by, ##EQU17##
That is, the collector current difference I c is the hyperbolic tangent function of the second fine voltage ΔV 2 .
Substituting Eq. (22) into Eq. (31) gives, ##EQU18##
Similarly, the collector current i c5 of the transistor 24 becomes the function of the external bias voltage V B , by ##EQU19## where, I c1 ' is the constant emitter current source and R x ' is the value of the resistor 13 connected between the emitters of the transistors 11 and 12.
Combining Eqs. (33) and (34), the collector current i c5 of the transistor 24 is given, as a function of V B and V in , by ##EQU20##
Thus, the total gain A v of the amplifier in FIG. 3 is given by, ##EQU21## where, V o is the output voltage from the amplifier and R L is the value of the output resistor 50.
The collector current i c4 of the transistor 43, expressed in Eq. (33), corresponds to the second current I2 in FIG. 2 and the collector current i c5 of the transistor 24 corresponds to the first current I1 in FIG. 2. Thus, the voltage gain of the amplifier composed as FIG. 3 is determined by the current and the resistance at the output terminal, as expressed in Eq. (36).
As described hereinabove, the amplifier for controlling linear gain of wide band according to the present invention can obtain the desired gain for the high-frequency and large-input signal without the distortion. | An amplifier for controlling the linear gain of wide band using an external bias voltage is disclosed to maintain the gain characteristics stably even for the high frequency input signals by adjusting the external bias voltage to prevent the amplified gain from being distorted or the gain from being decreased when increasing the linearity, where in a first fine voltage is generated with the inverse hyperbolic tangent function of the external bias voltage for adjusting the gain, a first voltage is generated with the hyperbolic tangent function of the first fine voltage and linearly proportional to the external bias voltage, a second fine voltage is generated with the inverse hyperbolic tangent function of the input signal voltage, a second voltage is generated with the hyperbolic tangent function of the second fine voltage for adjusting the first voltage, and the second voltage is converted to the linearly corresponding output signal voltage, thereby amplifying the gain even for the high frequency input signals, without any distortion. | 7 |
BACKGROUND
1. Field of the Invention
The present invention relates generally to the field of holography. More particularly, the present invention relates to systems and methods for shearless digital hologram acquisition system suitable for use with “white light” (spectrally broadband) or laser illumination, or two-color illumination. For two-color (more than two colors is also possible) implementations, the two colors may either both be broadband (low or very low coherence) illumination or laser illumination.
In one implementation, an LED (broadband light source) or laser is used for illumination, a diffractive or holographic optical element is used to create the required phase shift in a reference arm, and the hologram is recorded on a digital camera. In one implementation, advanced alignment and signal processing systems and methods, combined with the shearless geometry, afford a one-dimensional (1-D) FFT (Fast Fourier Transform) so that the processing time is substantially diminished compared to prior art systems that require a two-dimensional (2-D) FFT.
2. Related Art
Prior methods of heterodyne (spatial carrier frequency) classical holography and of digital hologram acquisition have required both laser (coherent) illumination and that the reference and object (target) beams be combined at some angle (there is a shear between the two beams). Lasers have a number of problems, including high expense and generally requiring very extensive safety precautions, which makes them even more expensive. Additionally, since lasers have long coherence lengths (compared to broader band illumination sources), small reflections from optical surfaces will interfere with and make significant noise in the digital hologram. Previous methods have also required an angle (shear) between the two beams to create the spatially heterodyne fringe pattern that actually records the hologram. The shear is created by reflecting the reference beam from a mirror or beamsplitter so that it propagates at a different angle than the object (target) beam. For common path systems, such as a Michelson geometry, or the last leg of a Mach-Zender geometry to the digital recorder, this means that the beams separate spatially from one another, and in fact makes it impossible to use a Michelson geometry for systems with high magnification-the reference beam becomes so separated due to the shear that it is either clipped by the optics, does not overlay the object beam, or both. Even with the shorter common path Mach-Zender layout, shear between the two beams often causes problems in achieving adequate overlay of the beams. For low-coherence illumination source beams it is substantially impossible in either geometry to get an exact enough overlay to form fringes with the prior art sheared systems. Another problem with prior art digital hologram acquisition systems is that they require a two-dimensional (2-D) FFT (Fourier transform) and inverse FFT to separate the object wave phase and amplitude from the hologram. The 2-D FFT/inverse FFT requires large computational power or a long wait. Another considerable problem with prior art systems is that they have no method for measuring phase changes greater than one wavelength or two-pi radians in a shearless geometry. This is a substantial disadvantage for holographic metrology.
FIG. 1 shows a prior art digital holography system with a Michelson geometry, where the shear angle between the two beams is indicated as a. Note that for this particular case, nominally a high-magnification case, the reference and object beams no longer have any overlap, as indicated, and therefore cannot form a hologram.
There is therefore a particular need for systems and methods for 1) recording digital holograms in a shearless geometry, 2) recording digital holograms with broadband very short coherence length (both transverse and longitudinal) illumination, 3) recording digital holograms which extend the range of metrology substantially beyond one wavelength and 4) reducing the FFT computational requirements for separating the object wave phase and amplitude from the hologram.
SUMMARY OF THE INVENTION
This disclosure is directed to systems and methods for shearless hologram acquisition that solve one or more of the problems discussed above.
The disclosed systems and methods may provide for single-beam or two (or more) color operation, and for separation of the object beam phase and amplitude from the hologram. The shearless geometry is highly suited for two (or more) color operation with either broadband or laser illumination, and systems and methods are introduced herein to enable this advanced metrology technique. The multi-color operation with shearless geometry extends the measurement capability of holographic metrology so that third-dimension measurements can be made without ambiguity over a much wider range with excellent overlay of the object and reference beams in Michelson, Mach-Zender, or other geometry in a shearless fashion.
One apparatus for shearless recording of a spatially heterodyne hologram with broad-band or laser illumination includes: an illumination source or sources; a beamsplitter optically coupled to the illumination source(s); a reference beam phase-shaping optical element optically coupled to the beamsplitter; an object optically coupled to the beamsplitter; a focusing lens optically coupled to both the reference beam phase-shaping optical element and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the phase-shaping optical element, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form a spatially heterodyne hologram.
This system and corresponding methods provide advantages in that the object and reference beams are unsheared and do not separate from one another as they travel a common optical path in space. Additionally, since the beams can be substantially perfectly overlapped with the shearless system and methods, no expensive and potentially dangerous laser is required for the illumination source, although the system is also perfectly compatible with laser illumination and also provides tremendous advantages for the case of laser illumination.
The systems and methods provide advantages in that computer assisted holographic measurements can be more easily and less expensively made with higher quality results. Additionally, the advanced systems and methods allow substantially decreased computation time or computational power by allowing the FFT's to be 1-D rather than 2-D, and two-color operation with the shearless geometry and 1-D FFT/IFFT provides a greatly expanded measurement range.
One particular embodiment comprises an apparatus to shearlessly record a hologram. The apparatus includes an illumination source configured to produce a first beam of light. The beam is split by a beamsplitter into a reference beam and an object illumination beam. The reference beam is directed onto a phase-shaping optical element which imparts a phase shift to the reference beam and returns the phase-shifted reference beam on itself to the beamsplitter. That is, the phase-shifted reference beam is returned in the same direction from which the non-phase-shifted reference beam was received, instead of being returned at an angle with respect to the received beam. The object illumination beam is directed onto an object, and a portion of the beam is reflected back to the beamsplitter. The beamsplitter receives the phase-shifted reference beam and object illumination beam and combines them substantially coaxially. The combined beams are passed through a focusing lens which focuses them at a focal plane. A digital recorder is positioned at the focal plane to record the spatially heterodyne hologram formed by the focused phase-shifted reference beam and reflected object illumination beam.
The illumination source may, for example, be a laser, light emitting diode (LED), a spectrally filtered incandescent light source, or an arc lamp. The phase-shaping optical element may, e.g., be a diffractive optical element with a blaze grating or a holographic optical element which is configured to impose a phase shift, such as a linear phase shift or repetitively increasing and decreasing phase shift, on the reference beam. The apparatus may include conditioning optics, such as a beam expander or spatial filter, positioned between the illumination source and the beamsplitter to optically process the first beam of light before it is received by the beamsplitter. The digital recorder may be a CCD or CMOS camera, and a digital storage medium may be coupled to the digital recorder to store the hologram data. The beamsplitter, the phase-shaping optical element, and the digital recorder may be configured according to various geometries, such as a Michelson geometry.
Another embodiment comprises a method for shearlessly recording a hologram. In this method, a beam of light is first provided. The beam is split into a reference beam and an object illumination beam. A phase shift is imparted to the reference beam, and an object is illuminated with the object illumination beam. The phase-shifted reference beam and a portion of the object illumination beam reflected from the object are then combined in a substantially coaxial manner. The phase-shifted reference beam and reflected object illumination beam are then focused at a focal plane, forming a spatially heterodyne hologram.
Numerous other embodiments are also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings.
FIG. 1 illustrates a schematic of a prior art high-magnification Michelson system indicating that shear has caused the reference and object beams to no longer overlap.
FIG. 2 shows a schematic of a particular embodiment of the present invention using Michelson Geometry, illustrating unsheared beams with diffractive or holographic Phase-Shaping Element in the Reference Arm.
FIG. 3 illustrates a schematic of a Two-Color Digital Holography System with shearless geometry suitable for 1-D FFT analysis.
FIG. 4 shows an Example of Carrier Frequency Fringes suitable for separation of Object Waves using Two-Color Digital Holography. While orthogonal carrier frequencies in real and Fourier space are advantageous, all that is required for a 1-D FFT is the ability to mathematically rotate an axis perpendicular to the carrier frequency of interest.
FIG. 5 depicts an example of a spectrally broadband illumination holography system with closely matched Reference and Object beam path lengths and reticle alignment target to allow precision overlay of the recombined beams at the digital camera.
While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiment which is described. This disclosure is instead intended to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
One or more embodiments of the invention are described below. It should be noted that these and any other embodiments described below are exemplary and are intended to be illustrative of the invention rather than limiting. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the present invention in detail.
As described herein, various embodiments of the invention comprise systems and methods for shearless hologram acquisition. Significant features of an apparatus for shearless digital hologram acquisition include the use of a phase-shaping optical element in the reference arm; using a broad-band illumination source with the optical paths, both longitudinal and transverse, matched to better than the longitudinal and transverse coherence lengths; arranging the system so that two (or more) colors can be used to record simultaneous holograms on the same digital camera exposure, or sequentially recording two (or more) colors on the same exposure by offsetting the direction of the carrier fringe recordation between the two (or more) colors; and building and aligning the system, or rotating the coordinate axes, so that the spatially heterodyne carrier frequency fringes are substantially aligned along either the x-axis or y-axis (or one color on the x-axis and one color on the y-axis for two-color recordation) of the system so that a 1-D FFT can be used rather than a 2-D FFT. The alignment can be replaced by axis rotations which make one axis of the coordinate system perpendicular to the carrier-frequency fringes of the object wave to be recovered from the hologram.
The systems and methods for advanced digital holography disclosed herein allow for the use of simpler optical systems, for the use of less expensive apparatus, for improved quality of digital hologram acquisition, and for improved methods of analysis of the hologram for determining the amplitude and phase of the original object wave at every recorded pixel. By contrast, the prior art does not describe any method for shearlessly forming a heterodyne (spatial carrier frequency) hologram. Shearless formation allows the use of the simpler Michelson geometry even in high magnification applications, and also remains an advantage for beam overlay even using the more complex Mach-Zender geometry. Neither does the prior art teach how to use broadband light for recordation of holograms, how to simultaneously or sequentially record holograms with two (or more) colors (either broadband or laser illumination) in a shearless geometry on the same digital camera exposure, or how to analyze the hologram for the original object wave phase and amplitude using only a one-dimensional (and therefore much faster) Fourier transform and inverse Fourier transform.
System Overview
Shear between the reference and object beam makes it impossible for the previous embodiments of digital holography to use a Michelson geometry at high magnifications, and prevents good overlay of the two beams (which is necessary for creation of fringes with broadband illumination) even in a Mach-Zender geometry. This problem is overcome by introducing a phase-shaping optical element (which can be a diffraction grating, holographic element, birefringent optical element, wedged glass, or other phase-modifying element), which modifies the phase of the wavefront without requiring reflection of the wave at a non-normal angle. Thus, after recombination, both the reference and object/target beams travel the optical path at substantially the same angle and can be overlaid substantially exactly on one another.
Additionally, prior-art embodiments of digital holography have not provided a shearless method for removing the ambiguity in phase measurements where the resolution-element-to-resolution-element difference in phase is greater than one wavelength. This problem is overcome by providing illumination at two or more different wavelengths or bands of wavelengths (“colors”) with a phase-shaping optical element for each color in the reference arm, and simultaneously or sequentially recording the digital hologram on the same exposure of the recordation device at two (or more) wavelengths where the required spatial carrier-frequency fringes are created by the phase shaping optical elements, rather than combining the beams at an angle. Use of the phase-shaping optical element allows the two beams to be combined in a co-linear fashion so that they can be exactly overlaid and form satisfactory carrier-frequency fringes even with low-coherence or spectrally broadband illumination.
Additionally, this shearless method of forming the holograms greatly simplifies proper illumination of the recordation device with the best optical quality of each of the individual beams. In sheared geometries, it is often very difficult to properly illuminate the recordation device with both beams since the shear causes them to spatially separate. In order to separate the two unsheared holograms in Fourier-space (after an FFT), the fringes created in real space by the phase-shaping optical element for one of the colors are created with a significantly different x and y component of the carrier frequency, compared to the spatial carrier frequency fringes created by the other color, so that when the 1-D FFT is performed, the holograms are substantially separated from one another in Fourier space, and the object waves can therefore be reproduced without any interference or cross-talk between the colors. In general, one of the carrier frequencies will have a much higher x-component frequency and the other carrier frequency will have a much higher y-component frequency, thus allowing separation of the object waves in Fourier space.
Aligning the carrier-frequency fringes of a single-color (for either broadband or laser illumination) hologram substantially parallel to either the x or y-axis allows a 1-D FFT to be used without axis rotation to retrieve the object beam phase and amplitude from the complex hologram by performing a 1-D FFT on the axis perpendicular to the fringes, translating the zero-frequency (0) axis location to the carrier frequency location, filtering around the new axis, and performing an inverse 1-D FFT. For two-color digital holography, if the fringes for one color are parallel to the x-axis and the fringes for the second color are parallel to the y-axis, then a 1-D FFT along the x-axis, axis-translation to the carrier frequency, filtering operation, and 1-D inverse FFT can be used to recreate the phase and amplitude of the second color object wave, and a 1-D FFT along the y-axis, axis translation, filtering operation, and 1-D inverse FFT can be used to recreate the phase and amplitude of the first color object wave. Similarly, rather than aligning the fringes parallel to either the x-axis or y-axis, it is possible to perform a mathematical coordinate rotation so that one of the axes is perpendicular to the carrier-frequency fringes. The axis rotation method of alignment of a coordinate axis to one set of carrier frequency fringes is in general useful when more than two holograms are recorded on the same digital recordation device, or when mechanically aligning the system (so that the fringes are created parallel to one of the system axes) is not convenient. This is another variation which allows use of the 1-D FFT rather than the 2-D FFT. More generally, a coordinate rotation allows use of the 1-D implementation even when the carrier frequencies cannot be made exactly orthogonal in real-space or Fourier space. The only requirement is that the difference in frequency components between the carrier frequencies is large enough that the undesired carrier frequency shows up as a substantially different frequency in the FFT transform of the. other carrier.
Note that, if desired, the methods described above can also be used for illumination sources of the same wavelength to either simultaneously or sequentially expose a single frame of the digital recordation device, thus allowing differential measurements of the target in the shearless geometry.
Detailed Description of Exemplary Embodiments
Shearless Digital Holography System
Referring now to FIG. 2 , a specific embodiment of a shearless holographic system is depicted. Light from an illumination source 210 passes through conditioning optics 220 , which may (or may not) include collimation, filtering, diffusion, or other optical conditioning of the light from the illumination source. The beam from illumination source 210 is split by a beamsplitter 230 into object and reference beams. The object beam strikes the target object 240 and returns through the beamsplitter 230 , while the reference beam is returned on itself by a phase-shaping optical element 250 (i.e., the returned beam is substantially coaxial with the original reference beam.) The phase-shifted reference beam is recombined with the object beam at the beamsplitter 230 . The combined beams (the phase-shifted reference beam and the returned object beam) are substantially co-linear and overlaid. A focusing lens 260 then focuses both beams simultaneously onto the recording array plane of a digital camera 270 , where the hologram and its spatial carrier frequency fringes created by the phase shift from the phase shaping optical element are recorded.
Examples of phase-shaping optical elements include: a holographic optical element formed by interfering counter-propagating co-linear waves where the hologram recording material is at an angle to the two beams; a blaze grating used in the −1 (minus one) order; a glass wedge followed by a mirror perpendicular to the beam path; a linearly increasing and decreasing glass wedge (the wedge reverses slope in a periodic fashion so that the average glass thickness is constant when averaged over a complete period for the wedge).
Two-Color Digital Holography System
Referring now to FIG. 3 , a specific embodiment of a two-color digital hologram acquisition system is depicted. This method is not limited to just two colors. Colors may be added to the system as long as the spatial carrier frequencies are arranged so that the object wave frequencies do not overlap in Fourier space. In this embodiment, light from two illumination sources ( 310 , 315 ) is combined by a dichroic mirror 320 (which could also be a simple beamsplitter or other form of beam combiner). The light from the illumination sources then passes through conditioning optics 330 , which may (or may not) include collimation, filtering, diffusion, or other optical conditioning of the illumination sources.
The substantially co-linear illumination beams (of both colors) are then split by a beamsplitter 340 into object and reference beams. The object beam strikes the target object 350 and returns through the beamsplitter 340 , while the reference beam is split into both of its colors by a dichroic mirror 325 or some other type of splitting element. Each individual color reference beam is returned on itself by a phase-shaping optical element ( 360 , 365 ), and the dichroic mirror 325 recombines the phase-shifted reference beams. Then, the combined reference beam is itself recombined with the object beam by the beamsplitter 340 . For the case where the phase-shaping optical element returns the beams substantially on themselves, the reference and object beams will be substantially co-linear and overlaid on one another after recombination. A focusing lens 370 then focuses both beams simultaneously onto the recording array plane of a digital camera 380 , which records the hologram and the spatial carrier frequency fringes created by the phase shift from the phase shaping optical element.
In order for the phase and amplitude of each color object beam to be individually separable from the other beams in Fourier space, the carrier frequency fringes in the camera recordation plane must be created at substantially different frequency components. FIGS. 4A-4D show an example where the carrier frequency fringes of Color 1 are perpendicular to the carrier frequency fringes of Color 2 . It should be noted that the subject matter of the figures (e.g., carrier frequency fringes) comprise variations in intensity that are normally depicted by shades of gray. The figures are black and white representations of the subject matter, which is sufficient for the purposes of the following description. For example, FIG. 4A is presented for the purposes of illustrating the horizontal fringes formed by Color 1 . Similarly, FIGS. 4B and 4C are presented to illustrate the vertical fringes formed by Color 2 , and the combined fringes of both colors, respectively. FIG. 4D is presented to illustrate the 2-D FFT of the 2-color hologram in FIG. 4C .
FIG. 4A illustrates the carrier frequency fringes achieved by arranging the Phase Shaping Optical Element (which could also be a mirror since this method is also compatible with sheared holography) for Color 1 , so that a linear vertical phase shift is created, resulting in horizontal fringes. FIG. 4B illustrates the carrier frequency fringes achieved by arranging the Phase Shaping Optical Element for Color 2 so that a linear horizontal phase shift is created, resulting in vertical fringes. FIG. 4C illustrates the simultaneous exposure of the digital camera to both fringe patterns. Finally, FIG. 4D shows the FFT of the image in FIG. 4C . Note that when the FFT is taken, the frequency component separation in x and y of the spatial carrier frequency fringe patterns from the two colors results in a total separation of the data in FFT space. The circles drawn on the figure indicate the separated sidebands for Color 1 and for Color 2 .
While a 2-D FFT is used to illustrate the separation of the beams in Fourier space, only a 1-D FFT and Inverse Fast Fourier Transform (IFFT) are required to recover each of the Object Beams. Thus, a 1-D FFT perpendicular to the spatial carrier frequency fringes, translation of axes to the carrier frequency for Color 1 , filtering operation, and an inverse FFT results in the phase and amplitude of the Object Wave for Color 1 only. A similar procedure results in recovery of the phase and amplitude of the Object Wave for Color 2 only.
Note that it is not necessary to use a 90-degree angle as the angle between the fringes of Color 1 and Color 2 . Other angles are entirely possible, but the advantage of using the 90-degree angle is that no axis rotation is required if the two carrier frequency fringe sets are parallel to the x and y axes. A 1-D FFT and IFFT can be used to recover the phase and amplitude of the object waves even for the case where the two sets of carrier frequency fringes are not orthogonal. In this case, an axis rotation must be carried out so that one of the axes is perpendicular to the carrier frequency under consideration. A 1-D FFT can then be carried out along this axis and the zero frequency location translated to the carrier frequency, the result filtered to only include the object beam frequencies under consideration, and then an inverse FFT produces the phase and amplitude of only that object wave. In the case where neither carrier frequency for either of the two colors is parallel to an axis, an axis rotation must be performed for each color to align one axis perpendicular to the carrier fringes for that color. Following this by a 1-D FFT, translation, filtering, and IFFT for each respective color returns the phase and amplitude of each of the respective colors.
Once the complex Object Waves for Color 1 and Color 2 are recovered as described above, then without any further processing (other than possible coordinate rotations if necessary to place them both in the same coordinate system,) one of the Object Waves is divided by the other Object wave, corresponding pixel by corresponding pixel (e.g., the complex value of the Object Wave for Color 1 at pixel ( 1 , 1 ) is divided by the complex value of the Object Wave for Color 2 at pixel ( 1 , 1 )). Since there is an average wavelength difference between the two colors, the resulting phase value created by dividing the two complex object waves by one another unambiguously extends the phase measurement range of the system. For instance, if there is a 10% difference in wavelengths between the two colors, then the phase measurement range over which phase is unambiguously measured is extended to 10 wavelengths (average wavelength divided by the difference between the two measurement wavelengths times the wavelength). This feature thus tremendously extends the usefulness of digital holographic measurements and makes it available in the very advantageous shearless geometry with only a 1-D FFT required.
One-Dimensional FFT for Object Wave Recovery
The use of a one-dimensional FFT for recovery of the Object Wave is illustrated by examining just one of the colors illustrated in FIG. 4 . For instance, if the Phase-Shifting Optical Element is arranged so that a linear vertical phase shift is induced, as illustrated by the horizontal fringes in FIG. 4A , then only a 1-D FFT in the y-direction (vertical axis) is required to recover the object wave phase and amplitude. A one-dimensional FFT in the y-direction, followed by an axis translation to the carrier frequency, followed by a filtering operation, followed by a 1-D IFFT, extracts the phase and amplitude of the object wave only, using just a 1-D FFT and IFFT, not the 2-D FFT and IFFT required by all prior art. Note that the digital Fourier transforms need not be FFT and IFFT, many other digital Fourier transforms besides the Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) will also work.
Use of Broadband Illumination for Digital Hologram Acquisition
It has been generally accepted that only highly coherent (laser) sources are suitable for holography, and digital holography has only been proposed using such sources in the prior art. In fact, although holography was invented in 1949, it languished on the shelf until the invention of lasers, followed by the invention of spatially heterodyne holography by Leith and Upatnieks. However, the use of laser illumination is not strictly required, and broadband (“white light”) illumination can be advantageous in many situations. In particular, not having laser illumination can greatly reduce the cost and complexity of a digital holography system, since many lasers are very expensive and require considerable safety precautions to prevent injury to users or bystanders.
For systems that require extremely low noise, broadband illumination is also an advantage. In highly coherent systems, extraneous reflections from lens surfaces that reach the recording camera interfere coherently with the designed reference and object beams, creating noise in the carrier fringes. With broadband illumination, the reflections from the lenses have traveled a distance different by more than the coherence length from the path traveled by the designed beams, and therefore cannot interfere coherently with the reference and object beams. The carrier frequency fringe noise is thereby tremendously reduced.
FIG. 5 provides an example of a system using broadband illumination. In this system, light is provided by an illumination source 510 , which in one embodiment may be a green LED. Light from illumination source 510 passes through conditioning optics 320 , which may, as noted above, perform collimation, filtering, diffusion, or other optical conditioning of the light. In this embodiment, the light from illumination source 310 is also passed through a reticle 530 and a lens 540 . The light beam is then split by a beamsplitter 550 into object and reference beams. In this embodiment, beamsplitter 550 is a split prism. The object beam strikes the target object 560 and returns through beamsplitter 550 , while the reference beam is returned on itself by a phase-shaping optical element 570 . The phase-shifted reference beam is recombined with the object beam at the beamsplitter 550 so that they are substantially co-linear and overlaid. A focusing lens 580 then focuses both beams simultaneously onto the recording array plane of a digital camera 590 , where the hologram and its spatial carrier frequency fringes created by the phase shift from the phase shaping optical element are recorded.
In order to use broadband illumination, the path lengths for the reference and object beams must be very carefully matched, to a difference less than the longitudinal coherence length of the illumination:
δ l<λ 2 /δλ,
where δl is the path length difference between the reference and object paths, λ is the average wavelength of the illumination source, and δλ is the spectral bandwidth of the illumination source. As an example, for illumination with a green LED of wavelength 530 nm and spectral bandwidth of 5 nm, the path lengths of the reference and object beams must be matched to better than ˜56 microns. This is easily achievable by closely matching the design pathlengths and then providing a piezoelectrically driven longitudinal motion for the phase-matching optical element. Such piezoelectric stages can have motion resolution of 10 nm or less. Many other methods of precisely matching the path lengths are also available.
Additionally, the object and reference beams must be exactly matched to one another in the transverse dimension, much more exactly than in any prior art implementation. The two beams must be recombined so that the exact areas that were split apart are joined back together to an accuracy better than the transverse coherence length (Born & Wolf, Seventh (expanded) Edition, p. 575, replace ρ, the source size, by Rδθ where R is the distance from the beamsplitter to the recombination plane):
δ r <( Kλ avg )/(δθ),
where δr is the allowable mismatch in overlay of the beams, K is a constant equal to 0.61 for no fringe contrast and smaller for good contrast, λ avg is the average wavelength of the broadband illumination source, and δθ is the divergence angle of the illumination source in radians. For instance, if the illumination source is a green LED with average wavelength of 530 nm, spectral bandwidth of 5 nm, and divergence angle after collimation of seven degrees, then the allowable error in overlay of the two beams is ˜6.5 microns if we use K=0.3 (˜33% spatial carrier frequency fringe contrast). Overlay of the two beams can be facilitated by passing the illumination beam through an alignment reticle 530 before splitting the beam, and arranging the optics such that the alignment reticle is also in focus at the digital recording plane. Clearly, in order to achieve this kind of overlay excellent optics and alignment must be used, but this is well within the actual state of the art.
Flat-Field Correction
The optical errors inherent in the system may be substantially removed by the method of flat-field correction. To make a flat field correction for reflection holography, the target is replaced by a flat reference surface which returns a plane wave. For a transmissive holography system, the object is simply removed from the system. A hologram is formed with the “perfect” target or with the target removed. The object wave from the “flat-field hologram” (reference hologram) is separated from the reference hologram by the standard methods of Fourier transform, axis translation, filtering, and Inverse Fourier transform. When a hologram is made of an object (target) to be analyzed, the complex object wave from the object under investigation may be divided by the complex object wave from the flat-field/reference hologram, and the optical wavefront errors and systematic noise are substantially removed from the measurement, greatly improving the accuracy of recreation of the object wave from the object/target under investigation.
Advantages
A shearless digital hologram acquisition system representing one embodiment of the invention is cost effective and advantageous for at least the following reasons. The shearless geometry allows a simpler Michelson geometry to be used for systems with arbitrary magnification, which is impossible with a sheared system, since the beams cease to overlap with one another (and therefore no hologram is created) for many implementations of the Michelson geometry. Even with a Mach-Zender geometry, the shear between the beams makes it difficult to adequately overlap the beams in many instances, and impossible for low coherence systems. For low coherence systems, the shearless geometry is a requirement, since it is otherwise impossible to overlap the beams so that they will interfere with one another-very low coherence illumination requires that the equivalent portions of the two beams overlap one another exactly. Use of the 1-D FFT, which is achieved by arranging the phase-shaping optical element so that the induced phase shift creates fringes parallel to either the x-axis or y-axis of the system or by rotating the coordinate system to have one axis perpendicular to the carrier frequency fringes, allows for substantially faster or less expensive (lower computational power) analysis of the holograms for separation of the object wave phase and amplitude from the raw spatially heterodyne hologram carrier frequency fringes.
There are many variations of the embodiments described above which are within the scope of the present disclosure and the appended claims. These variations may include, for example, the elimination of the focusing lens (e.g., 260 ,) which is used to eliminate the effects of diffraction. This may not be necessary for testing very flat optical surfaces, so the lens may not be used in some embodiments. In another alternative embodiment, the system may be configured so that the object illumination beam is passed through the target object, rather than being reflected from it. In an alternative embodiment of a multi-color system, the holograms of the different colors could be recorded by the recording device on separate frames, rather than a single frame. In another alternative embodiment, digital Fourier transforms or other kinds of frequency transforms could be used instead of the FFT's described above.
The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the claims. As used herein, the terms “comprises,” “comprising,” or any other variations thereof, are intended to be interpreted as non-exclusively including the elements or limitations which follow those terms. Accordingly, a system, method, or other embodiment that comprises a set of elements is not limited to only those elements, and may include other elements not expressly listed or inherent to the claimed embodiment.
While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed within the following claims. | Systems and methods for shearless digital hologram acquisition, including an apparatus incorporating an illumination source configured to produce a first beam of light, which is then split by a beamsplitter into a reference beam and an object illumination beam. The reference beam is directed onto a phase-shaping optical element which imparts a phase shift to the reference beam and returns the phase-shifted reference beam on itself to the beamsplitter. The object illumination beam is directed onto an object, and a portion of the beam is reflected back to the beamsplitter, which combines the phase-shifted reference beam and object illumination beam substantially coaxially. The combined beams are passed through a focusing lens which focuses them at a focal plane. A digital recorder is positioned at the focal plane to record the spatially heterodyne hologram formed by the focused phase-shifted reference beam and reflected object illumination beam. | 6 |
BACKGROUND OF THE INVENTION
The process used in the drilling of most oil and gas wells involves the use of a drilling fluid commonly referred to as drilling "mud" in the industry. The mud is injected under pressure through the drill string during drilling and returns to the surface through the drill string-borehole annulus. The mud performs multiple functions which include cooling of the drill bit, lubrication of the drill bit, providing a means of returning the drill cuttings to the surface of the earth and providing hydrostatic pressure to prevent the "blowout" of high pressure geologic zones when such zones are penetrated by the drill bit. Drilling mud comprises a liquid phase and a suspended solid phase. The liquid phase can be either fresh or saline water or even an oil base. The solid phase, which is suspended within the liquid phase, can comprise a multitude of materials blended to meet the particular needs at hand. As an example, barite (barium sulfate), with a specific gravity over 4.0, is often used as a weighting constituent to increase the bulk density of the mud when high pressure formations are being penetrated. Other additives are used to control drilling fluid circulation loss when certain types of high porosity, low pressure formations are penetrated. Once returned to the surface, the drilling fluid contains cuttings from the drill bit. Although most large cuttings are removed at the surface prior to recirculating the mud, smaller sized particles remain suspended within the drilling mud. Upon completion of the drilling operation, the drilling mud can sometimes be reconditioned and used again. Eventually, however, the mud can no longer be reprocessed and becomes classified as a waste product of the drilling operation.
Once the well has been successfully drilled and cased, hydrocarbons are extracted or produced from one or more formations penetrated by the borehole. Although hydrocarbons are the primary production fluids of interest, other non hazardous oilfield waste (NOW) is usually generated in the production of hydrocarbons. A water component is usually produced along with the hydrocarbon component, and in most areas of the world, the produced waters are saline. Although there are some secondary uses for produced waters, these waters are in general considered a waste product of the production operation. Solid wastes including sand, paraffin, sludges and other solid materials are also generated during the production operations. Large quantities of these solid wastes have been accumulated for decades in production pits. Environmental regulations have led to the need for disposal solutions for the materials contained in production pits undergoing remediation to acceptable environmental levels.
The isotopes uranium-238 and thorium-232, and the radioactive isotopes associated with the decay series of these isotopes, occur in nature in earth formations. In situ, the activities associated with these decay chains are relatively low and do not present a radiation hazard during the drilling operation. During well production, however, these naturally occurring radioactive materials (NORM) are dissolved in the produced waters and are transported to the surface. Over an extended period of time, the NORM becomes concentrated in precipitated scale associated with tubulars and surface equipment such as heater treaters, wellheads, separators and salt water tanks. Although the parent isotopes uranium-238 and thorium-232 are not generally present, the decay products or "daughter" products radium-226, radium-228, radon-222 and lead-210 can be found in oilfield waste. Radium-226, which coprecipitates with carbonates and sulfates of calcium, barium and strontium, is by far the greatest source of radioactive waste resulting from production activities. Once atoms of radium have replaced a sufficient number of atoms of the elements normally found in NOW waste to exceed a specified regulatory level, the waste is classified as NORM. Stated another way, there is no difference between NOW and NORM waste other than the level of radioactivity, which usually results from the radium content of NORM waste.
In summary, the drilling and production of oil and gas wells generates much waste. The wastes are classified as nonhazardous oilfield waste (NOW) and naturally occurring radioactive materials (NORM). NOW originating from drilling and production operations is primarily composed of drill cuttings, sand and spent material such as drilling mud which is no longer suitable for use and must be managed as waste under regulatory authority. Such mud might contain salts, non toxic metals such as sodium and calcium, toxic metals such as barium, chromium, lead, zinc and cadmium, and oil and grease contamination from the introduction of diesel oil (oil based mud), crude oil or a multitude of hydrocarbon based additives. The spent mud, with associated contaminants, comprises a liquid and a solid phase. NOW is also generated in production operations where copious amounts of saline water, along with some solids (sand), may be produced with the desired hydrocarbons. NORM originates primarily from production operations wherein the previously described radioactive scale contaminates not only large pieces of hardware such as well heads and separators but also can contaminate produced "waste" fluids such as salt water and associated solids. It is necessary to dispose of all types of waste, including those previously stored in pits, in a manner which will not contaminate the surface of the earth and not contaminate subterranean aquifers used as sources of drinking water.
Various methods are used to dispose of both NORM and NOW material. Oil and grease toxicity in NOW can be lowered by dilution techniques. Organics can be converted biologically to less toxic forms. Organics can also be removed by extraction processes. These extraction processes can utilize heat and may include methods such as thermal desorption or incineration. Oils can be removed by separation techniques and possibly produce a byproduct of commercial value. Organics can also be bound to solids thereby reducing their leachability and hazard to drinking water supplies. Salts can be diluted and discharged, chemically destroyed or rendered insoluble. Heavy metals can neither be biologically or chemically changed into less toxic species, therefore dilution with non contaminated materials is one method of controlling possible hazardous pollution. Heavy metals can be bound chemically thereby rendering them immobile and nonleachable into the environment. NORM can not be destroyed or chemically altered, therefore dilution with essentially non radioactive material to prescribed levels is an acceptable method. Other possible methods of disposal and/or storage of NORM include near surface burial, deposition with or without encapsulation into the wellbore of plugged and abandoned wells, and injection into geological formations at high pressures which exceed the fracture pressure of the injection formation.
The previous paragraph addresses current practices in the disposal of waste material by type of classification. Another set of disposal criteria has been developed around the physical form of the waste, namely solid or liquid. It should be recalled that spent drilling fluid is in the form of a slurry comprising liquid and solid components. U.S. Pat. No. 4,482,459 (now expired) to Carolyn Shiver, and assigned to the assignee of the current disclosure, teaches a method for continuous processing of a slurry of waste drilling mud fluids and water normally resulting from drilling operations. The process comprises the steps of conducting the drilling mud slurry to a slurry tank for liquid-solid separation by chemical and physical means. The separated solid and liquid components are treated and processed such that they are converted to a state suitable for reuse or release into the environment. There are a number of references which address the separation of liquid and solid components, and the processing of these components to render them harmless to the environment. All of the techniques mentioned above for the disposal of NOW and NORM and the processing of waste slurries are relatively expensive, time consuming, and may involve extensive handling, packaging, transportation and special regulatory permits.
The means of injecting liquid waste back into earth formations by means of a disposal well has been used for many years and remains the predominant method of disposal in the oil and gas industry. An injection well must meet certain criteria. Among these criteria are defined geologic conditions surrounding the injection well, proper casing and cementing of wells penetrating the injection zone, a maximum allowable surface injection pressure (MASIP) and specific procedures for periodic testing and reporting to various regulating agencies. MASIP varies from state to state and even from location to location within a given state dependent upon formation depth, hydrostatic pressure, etc. Being regulatory, MASIP is certainly subject to change in the future. These measures, which are established to prevent possible migration of the waste liquid into underground sources of drinking water (USDW), will be detailed in subsequent sections of this disclosure. Current injection technology requires that the particle size of the solid phase of any slurry first be minimized before injection. This is to prevent clogging or "sanding" of the perforations opposite the injection zone and also to prevent the filling of pore space throats of the injection zone thereby reducing permeability. Processing time and cost must be incurred, and the large particle size solid component of the slurry must still be disposed of in an environmentally acceptable manner. The density of the injected liquid is usually relatively low, varying between 1.00 gm/cc (˜8.34 lbs/gal) for fresh water to ˜1.1 to 1.2 gm/cc for brines. Often a considerable amount of pump pressure is required to overcome the pressure of the geologic formation and thereby inject the liquid. Adequate pump capacity can comprise an appreciable percentage of the total injection operation cost. In addition, the MASIP is set so as not to damage the tubular strings and the cement sheaths of the injection well and to not damage the injection formation. In some states disposal wells have been drilled into cavities within salt domes or sulfur deposits. In those states cavities are created within salt domes for this purpose, and in the case of sulfur deposits, result from the leach method of production of sulfur. Both of these formations provide impermeable "containers" for liquids but, unfortunately, are not widely distributed geographically and sometimes require that waste be transported a great distance in order to be disposed of in this type of facility.
SUMMARY OF THE INVENTION
The present invention is directed toward methods and apparatus for the disposal of both solid and liquid constituents of oil field waste slurry by injection into subterranean formations which are naturally fractured and may be inclined from the horizontal plane or "dipping". The invention is not limited to the disposal of oil field waste and therefore provides means and methods for the disposal of virtually any type of waste slurry stream.
Some preparation of the slurry at the earth surface is usually necessary prior to injection. Preliminary screening of the solid particulate material is desirable if the slurry is thought to contain large particulates. As an example, large pieces of cuttings in spent drilling fluids are removed from the slurry, pumped through some type of grinding or shearing equipment, and returned to the slurry only after their size has been reduced so that they pass through the screen of predetermined size. Particulate material can be classified as NOW or NORM type. Processing leading to dilution may be required by regulations affecting the specific injection well. Viscosifiers are used to aid in the suspension of the particulate material in the slurry. The viscosifier can be a naturally occurring clay mineral such as virgin bentonite with a specific gravity of ˜2.7. Montmorillonite is another suitable viscosifier. This type of viscosifier also adds weight to the slurry which assists in the injection process as will be described later. Virgin barite (barium sulfate) or other weighting material can also be used. Man made materials such as polymers can also be used as viscosifiers if the viscosifier is not requires to add additional weight to the slurry. In an alternate embodiment, products from surface recycling of NOW can also be used as a viscosifier, weighting agent, and diluent thereby recycling this NOW waste stream. Stated another way, byproduct generated by one waste processing method may be used as a key ingredient in a second waste disposal means.
Surface preprocessing can also be used on slurries containing relatively large concentrations of oil or grease. These components can be removed, or the concentrations reduced substantially, by using well known skimming and separation techniques. As mentioned previously, biodegrative agents and thermal methods can also be used to remove organic constituents such as oil and grease.
The selection of the zone or formation into which the slurry will be injected is of prime importance. The injection formation is preferably a limestone formation with high porosity and with a large fraction of the effective porosity being attributed to natural fractures. In addition, formation which have been partially depleted are also preferred. Commercial hydraulic fracturing methods can be used to induce fractures within the injection zone. The radial and vertical extent of induced fractures are usually rather limited thereby limiting the injection formation's capacity to receive injected material. The formation and associated fracture structure are preferably dipping with respect to the horizontal. Commercial acidizing techniques can also be used in carbonate injection formations thereby increasing the formation's receptivity to injected material. Current regulations specify that the injection formation must also be below any USDW and have an impermeable shale with a vertical thickness of at least 250 feet separating the injection formation from the USDW.
The injection well can be drilled specifically to the injection zone, or an existing well which penetrates a suitable injection formation can be modified to meet injection well standards. Current and proposed regulations require that the injection tubular of an injection well passing through an USDW be surrounded by two additional strings of casing, and that all tubular-borehole annuli be properly cemented for hydraulic isolation purposes. Tubulars are plugged at the lower vertical extent of the injection formation. The upper vertical extent of the injection formation is isolated by using a packer or other suitable means. Current practice is to first perforate only the lower portion of the injection zone. Should these perforations become plugged over the life of the injection operation, the injection formation can be perforated "up hole".
It has been determined that the slurry, processed and suspended with viscosifiers as outlined previously, flows into the selected injection formation with no clogging of the fractures or available pore space. This is because most of the effective porosity of the injection formation is in the form of fractures. The cross sectional areas of these fractures are normally orders of magnitude larger than the interstitial pore "throats" connecting effective pore space in non fractured consolidated or unconsolidated formations. The processed and suspended particulate material within the slurry can pass through the fractures without clogging. Since the injection formation is usually dipping from the horizontal and the injected slurry is weighted as previously discussed, flow is maintained with minimal pump pressure thereby reducing the costs of pumping and reducing the risk of damaging the hydraulic seals of the well and adversely affecting the injection formation. Experience has shown that with all other conditions being equal, the required injection pressure decreases as a function of the increasing dip of the injection zone and associated fracture system. Operational experience has also shown that for injection zones with sufficient dip combined with an appropriately weighted slurry, the slurry actually flows into the fractures due to the hydrostatic pressure head of the slurry column. Normal operation practice is, however, to maintain at least a nominal pump pressure for effective injection rates. The importance of low injection pressures are again emphasized in that pumping costs are reduced, the risk of damage to the well tubulars and cement sheaths are nil, and injection pressures are well below the fracture pressure of the injection formation.
In summary, methods and apparatus are presented for the disposal of waste slurry containing both liquids and solids by injecting this slurry into a subterranean formation through an injection well. The injection formation is selected to be a dipping, highly porous formation which is highly fractured thereby permitting the passage of the solid constituent of the slurry. Viscosifier is added to the slurry to (a) assist in suspending the solid particulate material and (b) add weight to the slurry thereby minimizing injection pumping requirements. Weighting material can also be added independently. If the slurry contains NORM, processing at the surface may be required to reduce the concentration of NORM to levels consistent with that permitted for the specific injection well being utilized. Processing may also be necessary to reduce the size of the particulates prior to injection. Furthermore, some preliminary skimming or separating at the surface of an abnormally high concentration of oil or grease may be required.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above cited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 illustrates a typical injection well which penetrates an USDW, an impermeable shale and the injection formation;
FIG. 2 is a schematic diagram of the surface apparatus and processes cooperating with an injection well which penetrates the injection formation; and
FIG. 3 depicts in block diagram form the preprocessing steps for the injected slurry prior to injection.
FIG. 4 illustrates a reduced feed flow manifold used in the preprocessing of the slurry prior to injection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is first drawn to FIG. 1 which illustrates a typical injection well. The borehole 10 extends from the surface of the earth 13 through an USDW 30, an impermeable shale zone 32 and into the injection formation 36. Slurry, depicted by the arrows 44, is injected from the surface through a tubular member 16 which is preferably production tubing. Extending from the surface 13 through the aquifer 30 are two additional strings of tubulars 14 and 12 whose longitudinal axes are essentially coincident with the axis of tubing 16. These tubulars are preferably standard steel casings used in the completion of oil and gas wells. The casing 12 terminates below the lowest vertical extent of the USDW 30 at the casing shoe 20. Cement 22 fills all tubular-borehole annuli. The USDW is, therefore, shielded from the flow of injected slurry by three strings of steel tubulars and cement. This arrangement is in compliance with current regulations for injection wells and insures an adequate vertical and radial hydraulic seal of the USDW. Tubing 16 and casing 14 extend through an impermeable shale whose vertical thickness 50 is a minimum of 250 feet to meet current injection well specifications. Through the impermeable shale and down to the packer 34, the casing-borehole annuli are filled with cement 22, again to insure hydraulic sealing to protect the aquifer from any vertical fluids migration. The borehole 10 penetrates an injection formation denoted by the numeral 36. The shale 32 serves as an impermeable barrier between the injection formation 36 and the aquifer 30. Packer 34 is positioned at the top of the injection formation. The casing 14 extends through the injection formation while the tubing 16 terminates in the vicinity of the lower boundary of the injection formation. Cement 22 fills the casing/borehole annulus in this region of the well. A cement plug 40 or other suitable bridging mechanism is positioned within the casing string 14 at the lower boundary of injection zone 36. Perforations are made in the casing 14 and the cement sheath thereby establishing fluid communication between the tubing 16 and the injection formation 36. Perforations are preferably made near the lower boundary of the injection interval. Should these perforations become blocked or clogged over time by the injection of waste slurries, new perforations can be made above the blocked perforations thereby maintaining a suitable flow path between the injection tubing and the injection formation.
Characteristics of the injection formation will next be examined. The formation is preferably high porosity with a high permeability in order to accept the injected slurries with minimal resistance. This allows low surface injection pressures which is a novel and critically important feature of the invention as discussed previously. Formations at least partially depleted of their virgin fluids if any are also desirable in that they tend to readily accept injected fluid. It is even more important that the formation dip in angle with respect to the horizontal as shown in FIG. 1. In certain instances, the injection formation might exhibit little or no dip at the point of penetration of the borehole, but dip significantly at distances radially removed from the borehole. An example would be an injection well drilled near the top of a geologic protrusion such as a salt dome. Finally, it is extremely important that a large fraction of the effective porosity of the formation be in the form of fissures or natural fractures as designated by the numeral 38. Such formations are quite commonly found on the flanks of salt domes or any other type of geological protrusion or up thrust. Cap rocks usually associated with these types of geological features provide the required impermeable barrier above the injection formation. Again, the combination of a dipping formation and a well developed system of interconnected fractures minimizes the resistance of the injection formation to the injected slurry thereby minimizing required surface injection pressures. The slurry, being weighted as mentioned previously, tends to flow primarily down dip under the influence of gravity and the hydrostatic pressure head of the slurry column. This flow is in the desired direction in that it is away from the USDW 30 located up hole. Geological studies have indicated that several reservoirs can accommodate on the order of 50 million barrels of waste slurry from a single injection well.
To summarize the function of the injection well depicted in FIG. 1, slurry is pumped from the surface of the earth 13 through tubing 16 into a region of the casing 14 isolated by the packer 34 and the cement plug 40. The injected fluid exits the borehole through perforations 46 and flows into the tilted, fractured injection formation 36. The path of flow within the injection zone occurs primarily within the fracture system 38 and the flow is down dip as illustrated by the arrows 48.
As an alternate embodiment (not shown), the injection well can be cased and cemented from the surface to the top of the injection zone. This form of open end completion is possible in highly consolidated, vertically fractured injection formations. Since the injection formation is not cased and cemented, perforations are not needed to establish hydraulic communication between the injection zone and the surface of the earth.
The functional relationships between the surface elements of the invention, the injection well and the injection formation are illustrated in FIG. 2. The waste slurry, designated by the numeral 70, enters the system at input 74. The water component of the waste can be salt water or fresh water. Waste slurry can be delivered to the disposal site by barge, boat, truck, pipeline or any other operationally and economically feasible means. Certain preprocessing steps are then performed at the block designated as 72. These preprocessing steps include the adding of the viscosifier and weighting agent, screening of particulates and other steps which have been mentioned previously and will be discussed in detail in a following section. Once preprocessing has been completed, the waste slurry exits at output 76 and enters a holding tank. At this point, the waste 70 comprises a slurry of liquid and suspended solid particulate material and has been preprocessed to meet all operational and regulatory requirements. It should also be noted that the slurry is at atmospheric pressure. The slurry is then pumped from the holding tank 70 through fitting 71 into tubing 16 within the injection well. The pressure requirements of the pump are not stringent since the slurry has been weighted and it is being pumped into a highly fractured, dipping injection formation 36. Pumps generating surface pressures of 100 psi or less have been found sufficient to maintain a reasonable disposal rate in suitable injection formations. By contrast, conventional injection requires a much higher MASIP. In some situations, the slurry requires no pumping and flows into the injection formation by means of a siphoning effect driven by the hydrostatic head of the weighted slurry column. That is, if the pump 62 is shut off and the valve 66 in pump bypass line 64 is opened, the waste 70 will flow from tank 60 into the dipping injection formation 36 as depicted by arrows 48.
Attention is now directed toward the preprocessing steps, each of which will be discussed in detail. The preprocessing steps are shown in block diagram in FIG. 3. There is some flexibility in the sequence of the steps. The sequence depicted in FIG. 3 is selected for purposes of discussion only.
In the previous discussion of non hazardous oilfield waste (NOW) and naturally occurring radioactive material (NORM), it was mentioned that essentially all earth material contains some background level of naturally occurring radioactivity which include isotopes which emit alpha and beta particles as well as gamma radiation. Generally speaking, material classified as NOW are considered "non radioactive" in the sense that their level of naturally occurring radioactivity is below a regulated level. Current regulations classify any material with equivalent radium-226 specific activity below 30 pico Curies per gram of sample in the NOW category. Current regulations also allow NOW material to be disposed in injection wells of the type described in the previous paragraphs. Any waste material received for injection disposal must be monitored to determine if it is classified as NORM or NOW material. If the waste has a radioactive level that exceeds the regulatory limit at which NOW becomes NORM, dilution may be required before disposal into some wells. This step is shown at block 80 of FIG. 3. The diluent might be liquid such as brine or other available waste from drilling or production operations. Alternately, the addition of viscosifier and weighting material might suffice to bring the waste within the NOW category if the order of the steps of FIG. 3 are rearranged. It should be noted that the 30 pico Curie level is a regulatory limit. This limit is subject to change, and injection wells with unregulated or unlimited radioactivity restrictions might be permitted.
Excessive concentrations of grease or oil are removed from the waste prior to injection for environmental and possible economic reasons. This process is shown at block 82 of FIG. 3. One method of removal is gravity separation using a commercially available gun barrel separator. If the concentration of oil in the waste is equal to or greater than 1 barrel per 2000 barrels of waste, skimming techniques are used to remove the oil constituent. It is possible that the value of the skimmed oil exceeds the cost of skimming thereby producing a byproduct of net economic value.
Although one of the novel features of the invention is the ability to inject solid particulate material along with the liquid phase of the waste, experience has shown that there are some limitations to the size of the particulates in order to achieve an efficient injection program. The waste may include relatively large particles of solid material such as "chunks" of drill bit cuttings. Although the maximum size of particle that can be injected is a function of many factors including the fracture system of the injection zone, experience has shown that particles up to 2-5 millimeters in diameter can be effectively injected in most operations. The incoming waste is screened with, as an example, a 10 mesh screen as shown generally at block 84 of FIG. 3. Particles which do not pass through the screen are diverted to a grinding or shearing system to reduce their size as illustrated at block 88. Such means might be a sand pump or other suitable grinding apparatus. The ground particles are then reintroduced to the main stream of the preprocessing operation at block 84 for a second screening. The screening operation 84 and particle reduction operation 88 are repeated until the particulate material is reduced to or below the predetermined size. It should again be noted that the 10 mesh size specification is rather arbitrary and dependent upon many factors including the fracture system of the injection reservoir. Particulates as large as sand have been successfully suspended and injected, as well as shale cuttings as large as 5 millimeters in diameter
It is advantageous to reduce the flow pressure of the slurry during the screening operation 84. This is accomplished in the preferred embodiment of the invention by using a reduced flow feed manifold depicted in FIG. 4. Slurry flows into the manifold through input line 90 and first enters and partially fills an essentially cylindrical portion of the manifold identified by the numeral 92. For a four inch input flow line 90, the dimension identified by the arrow 97 is preferably be about ten inches and the dimension identified by the arrow 95 is approximately four feet. The effective cross section of the flow is significantly increased by the cylindrical portion 92 of the manifold thereby reducing the flow pressure. Slurry flows from the cylindrical portion of the manifold through a slightly constricting conduit 94 with a rectangular cross section. The dimension identified by the numeral 98 is approximately one inch or less. The slurry exits the reduced flow feed manifold as depicted by the arrows 96 and flows to the previously described screening operation.
Viscosifiers and possibly weighting material is added to the waste stream at block 86 of FIG. 2. A possible viscosifier is virgin bentonite which is a clay mineral with a specific gravity of approximately 2.7. Since the specific gravity of the viscosifier is relatively large, it may also serve as a weighting agent. It is desirable to bring the viscosity of the waste stream to a funnel viscosity in the range of approximately 60-90 seconds per quart for efficient operation. At this viscosity and with particulates in the ideal size range of 2 millimeters in diameter or less (10 mesh sieve), a slurry containing 15 to 35% solids can be obtained and successfully injected. Barite (barium sulfate) with a specific gravity of over 4 can be used as an independent weighting agent. The amount of material added for the sole purpose of weighting the slurry is, of course, a function of the amount of waste particulates in the slurry. It has been found that a slurry weight of 10 lbs/gal or more is beneficial for most injection operations.
A second embodiment of the invention involves the use of waste material from other NOW waste processing operations in place of virgin clays as a viscosifier and weighting material. A surface processing method for NOW material, offered commercially by the assignee of the current invention, generates a material that is very high in clay content and would be very useful as a viscosifier and a weighting agent in the present invention. That is, recycled material from one type of processing could be used in the disposal technique of the present invention thereby eliminating the need to use any virgin material. This is both environmentally and economically desirable as no additional volume of NOW is created.
In most operations, it has been found that the pH of most preprocessed slurry falls within the range of 6 to 8. If, for any reason, the preprocessed material is sufficiently corrosive to cause damage the processing or injection apparatus or even to the injection formation, the pH can be adjusted in the preprocessing steps preferably after step 86.
The preprocessed waste is output at the point indicated schematically by the numeral 76 and passed to pump 62 for injection into the injection zone.
While the methods and apparatus herein described constitute the preferred embodiment of this invention, it is to be understood that the invention is not limited to these precise methods and forms of apparatus and that changes may be made therein without departing from the scope of the invention. | Methods and apparatus for the disposal of solid particulate material in subterranean formations are disclosed. The invention is not limited to the disposal of oil field waste and therefore provides means and methods for the disposal of virtually any type of waste slurry stream. A slurry is formed at the surface of the earth by mixing the solid waste in particulate form with liquid and viscosifier thereby forming a slurry. A borehole is drilled into a selected injection formation and the slurry is pumped from the surface through the borehole and into the injection formation. Some surface pretreating of the slurry may be required including sizing of the particulate solids, adding weighting material, removing excessive amounts of oil and grease and diluting to reduce the level of radioactivity. The injection formation is preferably dipping in angle with respect to the horizontal and highly fractured. The borehole is hydraulically isolated from intervening earth strata between the surface of the earth and the injection formation. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/152,535filed on May 20, 2002, and claims priority under 35 U.S.C. 119 of Danish application no. 0317/97 filed on Mar. 20, 1997, of U.S. provisional application No. 60/041,390 filed on Mar. 27, 1997 and the benefit of application Ser. Nos. 09/045,038, 09/836,496, 10/152,535 and 10/978,110 filed on Mar. 20, 1998, Apr. 17, 2001, May 20, 2002, and Oct. 29, 2004 respectively, in the U.S. is claimed under 35 U.S.C. 120, the contents of all of which are fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to zinc free insulin crystals having a diameter below 10 μm and to therapeutic powder formulations suitable for pulmonary administration comprising such insulin crystals.
BACKGROUND OF THE INVENTION
[0003] Diabetes is a general term for disorders in man having excessive urine excretion as in diabetes mellitus and diabetes insipidus. Diabetes mellitus is a metabolic disorder in which the ability to utilize glucose is more or less completely lost. About 2% of all people suffer from diabetes.
[0004] Since the introduction of insulin in the 1920's, continuous strides have been made to improve the treatment of diabetes mellitus. To help avoid extreme glycaemia levels, diabetic patients often practice multiple injection therapy, whereby insulin is administered with each meal.
[0005] Insulin is usually administrated by s.c. or i.m. injections. However, due to the adherent discomfort of injections alternative ways of administration such as nasal and pulmonary has been extensively investigated. For a review on alternative routes of administration of insulin, see Danielsen et al. New routes and means of insulin delivery, in: Childhood and Adolescent Diabetes (Ed. Kelnar), Chapman & Hall Medical, London 1994, pp. 571-584.
[0006] In order to circumvent injections, administration of insulin via the pulmonary route could be an alternative way to provide absorption profiles which mimic the endogenous insulin without the need to inject the insulin.
DESCRIPTION OF THE BACKGROUND ART
[0007] Administration of insulin via the pulmonary route can be accomplished by either an aqueous solution or a powder preparation. A description of the details can be found in several references, one of the latest being by Niven, Crit. Rev. Ther. Drug Carrier Sys, 12(2&3):151-231 (1995). One aspect covered in said review is the stability issue of protein formulations, aqueous solutions being less stable than powder formulation. So far, all powder formulations have been described as mainly amorphous.
[0008] A review of the permeation enhancers useful for the promotion of trans-mucosal absorption is found in Sayani et al., Crit. Rev. Ther. Drug Carrier Sys, 13(1&2): 85-184 (1996).
[0009] Patton et al., Inhale Therapeutic Systems, PCT WO 95/24183, claim a method for aerosolising a dose of insulin comprising providing the insulin as a dry powder dispersing an amount of the dry powder in a gas stream to form an aerosol capturing the aerosol in a chamber for subsequent inhalation.
[0010] It has been found that when insulin is combined with an appropriate absorption enhancer and is introduced into the lower respiratory tract in the form of a powder of appropriate particle size, it readily enters the systemic circulation by absorption through the layer of epithelial cells in the lower respiratory tract as described in U.S. Pat. No. 5,506,203. The manufacturing process described in said patent, comprising dissolution of insulin at acid pH followed by a pH adjustment to pH 7.4 and addition of sodium taurocholate before drying the solution by vacuum concentration, open drying, spray drying, or freeze drying, results in a powder composed of human insulin and absorption enhancer. The powder is characterized as mainly amorphous determined under a polarized light microscope. The desired particle size distribution is achieved by micronizing in a suitable mill, such as a jet mill, and the components may be mixed before or after micronizing. The biological effect of the powder obtained according to the methods described in this patent is only seen in the presence of a substantial amount of enhancer.
[0011] Platz et al., Inhale Therapeutic Systems, PCT WO 96/32149, describes spray drying of zinc insulin from a solution containing mannitol and a citrate buffer, pH 6.7. The inlet temperature is 120 to 122□C, the outlet temperature 80-81□C. The mass median aerodynamic diameter, MMAd, of the obtained insulin particles was determined to 1.3 to 1.5 μm.
[0012] In his thesis, “Insulin Crystals”, Munksgaard Publisher 1958, p. 54-55, Schlichtkrull describes crystallisation of zinc free, recrystallised porcine insulin from a solution comprising 0.01 M sodium acetate and 0.7%˜0.12 M sodium chloride and 0.1% methyl-parahydroxybenzoate and using a pH of 7.0. The crystals obtained were 10-50 μm rhombic dodecahedral crystals showing no birefringence.
[0013] Jackson, U.S. Pat. No. 3,719,655 describes a method of purification of crude porcine and bovine insulin by crystallisation. Zinc free crystals of insulin are obtained by crystallisation at pH 8.2 (range 7.2-10) in the presence of 0.5 M (range 0.2 M-1 M) of a sodium, potassium, lithium or ammonium salt. Crystallisation is achieved by addition of 1 N alkali metal hydroxide or 1 N ammonia to a solution of crude insulin in 0.5 N acetic acid to a pH of 8.2 is obtained. Alternatively, crystallisation is achieved in an aqueous solution of impure insulin at pH 8.2 by addition of solid sodium chloride to a concentration of sodium ions of 0.45 M. The crystals appear in the octadecahedral or dodecahedral forms, i.e. crystals belonging to the cubic crystal system.
[0014] Baker et al., Lilly, EP 0 709 395 A2 (filed Oct. 31, 1994) describe a zinc free crystallisation process for Lys B28 -Pro B29 human insulin characterised by adjustment of the pH of a strongly buffered acid solution containing metal cations or ammonium ions and a preservative with metal hydroxide or ammonia to a value between 8.5 and 9.5.
[0015] The known methods for the manufacture of insulin particles of the desired size for pulmonary administration are cumbersome, generates problems with insulin dust and the investments in equipment are large. Furthermore, insulin is exposed to conditions where some denaturation is likely to take place. Thus WO 96/32149 disclose spray drying in a temperature range of 50□C to 100□C, followed by milling of the particles to achieve to desired particle size.
[0016] Furthermore, the known powder formulations for pulmonary administration which have been described as mainly amorphous have a tendency to associate into aggregates in the dry powder.
DESCRIPTION OF THE INVENTION
[0000] Definitions
[0017] The expression “enhancer” as used herein refers to a substance enhancing the absorption of insulin, insulin analogue or insulin derivative through the layer of epithelial cells lining the alveoli of the lung into the adjacent pulmonary vasculature, i.e. the amount of insulin absorbed into the systemic system is higher than the amount absorbed in the absence of enhancer.
[0018] In the present context the expression “powder” refers to a collection of essentially dry particles, i.e. the moisture content being below about 10% by weight, preferably below 6% by weight, and most preferably below 4% by weight.
[0019] The diameter of the crystals is defined as the Martin's diameter. It is measured as the length of the line, parallel to the ocular scale, that divides the randomly oriented crystals into two equal projected areas
[0000] Brief Description of the Invention
[0020] It is an object of the present invention to provide an insulin powder suitable for pulmonary delivery which has a reduced tendency to associate into aggregates in the dry powder compared to the pulmonary insulin particles described in the prior art.
[0021] According to the present invention this object has been accomplished by providing zinc free insulin crystals having a diameter below 10 μm.
[0022] The crystals of the present invention furthermore exhibit a better stability profile than powders of essentially the same composition prepared by spray drying, freeze-drying, vacuum drying and open drying. This is probably due to the amorphous state of powders prepared by the other methods described. By this means it is possible to store the powder formulations based on the crystals of the present invention at room temperature in contrary to human insulin preparations for injections and some amorphous insulin powders without stabilizing agent which have to be stored between 20□C to 8□C.
[0023] Furthermore, therapeutical powder formulations comprising the insulin crystals of the invention elucidates better flowing properties than corresponding amorphous powder formulations.
[0000] Preferred Embodiments
[0024] The zinc free insulin crystals of the invention are advantageously provided in a crystal structure belonging to the cubic crystal system, preferably in the octadecahedral or dodecahedral crystal forms, since these crystal forms result in readily soluble product having excellent flowing properties.
[0025] The diameter of the insulin crystals is advantageously kept in the range of 0.2 to 5 μm, preferably in the range of 0.2 to 2 μm, more preferably in the range of 0.5 and 1 μm, to ensure high bioavailability and suitable profile of action, see PCT application No. WO 95/24183 and PCT application No. WO 96/32149.
[0026] In a preferred embodiment the insulin used is selected from the group consisting of human insulin, bovine insulin or porcine insulin, preferably human insulin.
[0027] In another preferred embodiment the insulin used is selected from the group consisting of rapid-acting insulins, preferably des(B30) human insulin, Asp B28 human insulin or Lys B28 Pro B29 human insulin.
[0028] In another preferred embodiment the insulin used is an insulin derivative, preferably selected from the group consisting of B29-N ε -myristoyl-des(B30) human insulin, B29-N ε -palmitoyl-des(B30) human insulin, B29-N ε -myristoyl human insulin, B29-N ε -palmitoyl human insulin, B28-N ε -myristoyl Lys B28 ProB29 human insulin, B28-N ε -palmitoyl Lys B28 ProB29 human insulin, B30-N ε -myristoyl-Thr B29 Lys B30 human insulin, B30-N ε -palmitoyl-Thr B29 Lys B30 human insulin, B29-N ε -(N-palmitoyl-γ-glutamyl)-des(B30) human insulin, B29-N ε -(N-lithocholyl-γ-glutamyl)-des(B30) human insulin, B29-N ε -(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N ε -(ω-carboxyheptadecanoyl) human insulin, more preferably Lys B29 (N-εacylated) des(B30) human insulin.
[0029] The insulin derivatives has a protracted onset of action and may thus compensate the very rapid increase in plasma insulin normally associated with pulmonary delivery. By carefully selecting the type of insulin, the present invention enables adjustment of the timing and to obtain the desired biological response within a defined time span.
[0030] In order to avoid irritation of the lungs and to eliminate immunological reactions, the employed insulin is preferably insulin which has been purified by chromatography, such as MC insulin (Novo), Single Peak insulin (E. Lilly) and RI insulin (Nordisk).
[0031] In a preferred embodiment the zinc free insulin crystals according to the invention further comprise a stabilizing amount of a phenolic compound, preferably m-cresol or phenol, or a mixture of these compounds.
[0032] The present invention is furthermore concerned with a therapeutic powder formulation suitable for pulmonary administration comprising the zinc free crystals described above.
[0033] In a preferred embodiment this therapeutic powder formulation further comprises an enhancer which enhances the absorption of insulin in the lower respiratory tract.
[0034] The enhancer is advantageously a surfactant, preferably selected from the group consisting of salts of fatty acids, bile salts or phospholipids, more preferably a bile salt.
[0035] Preferred fatty acids salts are salts of C 10-14 fatty acids, such as sodium caprate, sodium laurate and sodium myristate.
[0036] Lysophosphatidylcholine is a preferred phospholipid.
[0037] Preferred bile salts are salts of ursodeoxycholate, taurocholate, glycocholate and taurodihydrofusidate. Still more preferred are powder formulations according to the invention wherein the enhancer is a salt of taurocholate, preferably sodium taurocholate.
[0038] The molar ratio of insulin to enhancer in the powder formulation of the present invention is preferably 9:1 to 1:9, more preferably between 5:1 to 1:5, and still more preferably between 3:1 to 1:3.
[0039] The powder formulations of the present invention may optionally be combined with a carrier or excipient generally accepted as suitable for pulmonary administration. The purpose of adding a carrier or excipient may be as a bulking agent, stabilizing agent or an agent improving the flowing properties.
[0040] Suitable carrier agents include 1) carbohydrates, e.g. monosaccharides such as fructose, galactose, glucose, sorbose, and the like; 2) disaccharides, such as lactose, trehalose and the like; 3) polysaccharides, such as raffinose, maltodextrins, dextrans, and the like; 4) alditols, such as mannitol, xylitol, and the like; 5) inorganic salts, such as sodium chloride, and the like; 6) organic salts, such as sodium citrate, sodium ascorbate, and the like. A preferred group of carriers includes trehalose, raffinose, mannitol, sorbitol, xylitol, inositol, sucrose, sodium chloride and sodium citrate.
[0041] The crystals of the present invention are advantageously produced according to the following procedure:
providing a solution of insulin having a pH between 7.0 and 9.5; mixing said solution with a solution of a salt of an alkali metal or an ammonium salt; and recovering the formed crystals.
[0045] The salt of an alkali metal or ammonium is preferably selected from the group consisting of the hydrochloride or acetate of sodium, potassium, lithium or ammonia, or mixtures thereof, more preferably sodium acetate.
[0046] In order to suppress the solubility of the crystals formed, the solution of insulin and/or the solution of a salt of an alkali metal or an ammonium salt preferably comprises a water miscible organic solvent in an amount which corresponds to 5 to 25% (v/v) in the solution obtained after mixing.
[0047] The water miscible organic solvent is preferably selected from the group consisting of ethanol, methanol, acetone and 2-propanol, more preferably ethanol.
[0048] A very uniform distribution of crystal sizes and crystals of the same crystallographic form are obtained when the two solutions are mixed within a period of less than 2 hours, preferably less than 1 hour, more preferably less than 15 minutes, still more preferably less than 5 minutes.
[0049] The crystallisation process by which uniformly sized, small, zinc free crystals is obtained directly, without the use of milling, micronizing, sieving and other dust generating steps, is much to be preferred from the present state of the art in the manufacture of insulin powders for inhalation.
[0050] The concentration of insulin after mixing is preferably between 0.5% and 10%, more preferably between 0.5% and 5%, still more preferably between 0.5% and 2%.
[0051] The concentration of salt after mixing is preferably between 0.2 M and 2 M, more preferably about 1 M.
[0052] The method according to the present invention may further comprise a washing step, in which the crystals obtained are washed with a solution comprising auxiliary substances to be included in the final dry powder, preferably an enhancer and/or a carbohydrate, and optionally comprising 5-25% of an alcohol, preferably ethanol, 5-50 mM of a preservative preferably phenol, and 0.1-2 M of a salt such as sodium acetate.
[0053] This invention is further illustrated by the following examples which, however, are not to be construed as limiting.
EXAMPLE 1
[0054] Crystallisation in 1 M sodium acetate. 2 g of highly purified human insulin is dissolved in 100 nl 10 mM tris buffer, pH 8.0 in 20% (v/v) of ethanol in water. To this solution is added 100 nl 2 M sodium acetate under stirring. A precipitate forms immediately. After 2 days at room temperature microscopy shows small crystals having a diameter between 0.5 and 1 μm. The crystals are collected by centrifugation at −10□C, washed once with 20 ml ice cold 10% ethanol (v/v) in water, isolated by centrifugation and dried by lyophilization. The obtained crystals are shown in FIG. 1.
EXAMPLE 2
[0055] Crystallisation in the presence of taurocholic acid sodium salt.
[0056] 10 mg of human insulin and 5 mg of taurocholic acid sodium salt are dissolved in 500 μl 10 mM tris buffer, pH 8.0 in 20% (v/v) of ethanol in water. To this solution is added 500 μl 2 M sodium acetate. Microscopy after 1 hour and after 24 hours shows identically appearance of the crystals, i.e. uniformly sized crystals having diameters between 0.5 and 1 μm. The crystals were washed three times with 100 μl 10% (v/v) ethanol in water at −10□C and dried in vacuo. HPLC of the crystals showed that the washings had removed the taurocholic acid sodium salt from the insulin crystals.
EXAMPLE 3
[0057] Crystallisation in the presence of Tween 80, bis(2-ethylhexyl) sulfosuccinate sodium salt, chitosan, L-α-lysophosphatidylcholine myristoyl and polyoxyethylene sorbitan monolaurate.
[0058] Crystallisation was performed as described in Example 2 except that taurocholic acid sodium salt was replaced by 0.6% (w/v) Tween 80, 0.56% (w/v) bis(2-ethylhexyl) sulfosuccinate sodium salt, 0.32% (w/v) chitosan, 0.52% (w/v) L-α-lysophosphtidylcholine myristoyl, and 1% (w/v) polyoxyethylene sorbitan monolaurate, respectively. All five examples resulted in uniformly sized crystals having diameters between 0.5 and 1 μm.
EXAMPLE 4
[0059] Crystallisation in 10% (v/v) ethanol.
[0060] Crystallisation was performed in 10% (v/v) ethanol as described in Example 1, using 4 combinations of pH and concentration of sodium acetate:
4.1: pH 7.5 and 1 M sodium acetate 4.2: pH 7.5 and 1.5 M sodium acetate 4.3: pH 9.0 and 1 M sodium acetate 4.4: pH 9.0 and 1.5 M sodium acetate
[0065] All 4 combinations yielded uniformly sized crystals having diameters between 0.5 and 1 μm.
EXAMPLE 5
[0066] Crystallisation in 15% (v/v) ethanol.
[0067] Crystallisation was performed in 15% (v/v) ethanol, using 6 combinations of pH and concentration of sodium acetate:
5.1: pH 7.5 and 1 M sodium acetate 5.2: pH 7.5 and 1.5 M sodium acetate 5.3: pH 7.5 and 2 M sodium acetate 5.4: pH 9.0 and 1 M sodium acetate 5.5: pH 9.0 and 1.5 M sodium acetate 5.6: pH9.0 and 2 M sodium acetate
[0074] All 6 combinations yielded uniformly sized crystals having diameters between 0.5 and 1 μm.
EXAMPLE 6
[0075] Crystallisation in 20% (v/v) ethanol.
[0076] Crystallisation was performed in 20% (v/v) ethanol using 4 combinations of pH and concentration of sodium acetate:
6.1 : pH 7.5 and 1 M sodium acetate 6.2 : pH 7.5 and 1.5 M sodium acetate 6.3 : pH 7.5 and 2 M sodium acetate 6.4 : pH 9.0 and 1 M sodium acetate
[0081] All 4 combinations yielded uniformly sized crystals having diameters between 0.5 and 1 μm.
EXAMPLE 7
[0082] Crystallisation at pH 7.5, 8.0, 8.5 and 9.0 in 20% ethanol (v/v) using slow addition of sodium acetate.
[0083] Crystallisation was performed using solutions as described in Example 1, except that the 2 M sodium acetate was dissolved in 20% (v/v) ethanol in water. The pH of the insulin solutions were adjusted to 7.5, 8.0, 8.5 and 9.0, respectively. The sodium acetate solution was added in 12 aliquots over a period of 2 hours, using 10 min between additions. At all 4 pH values uniformly sized crystals having diameters between 0.5 and 1 μm were obtained.
EXAMPLE 8
[0084] Crystallisation of Lys B29 (ε-myristoyl) des(B30) human insulin in the presence of taurocholic acid sodium salt.
[0085] 10 mg of Lys B29 (ε-myristoyl) des(B30) human insulin and 5 mg of taurocholic acid sodium salt are dissolved in 500 μl 10 mM tris buffer, pH 8.0 in 20% (v/v) of ethanol in water. To this solution is added 500 μl 2 M sodium acetate. Microscopy after 1 hour and after 24 hours shows identically appearance of the crystals, i.e. uniformly sized crystals having diameters between 0.5 and 1 μm. The crystals were washed once with 300 μl 10% (v/v) ethanol in water at −10□C and dried in vacuo. HPLC of the crystals showed that the washings had removed the palmitoyl-Thr B29 Lys B30 human insulin, B29-N ε -(N-palmitoyl-γ-glutamyl)-des(B30) human insulin, B29-N ε -(N-lithocholyl-γ-glutamyl)-des(B30) human insulin, B29-N ε -(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N ε -(ω-carboxyheptadecanoyl) human insulin. | The invention relates to a formulation comprising a polypeptide selected from at least one of insulin, an insulin analog, and an insulin derivative; at least one surfactant; optionally at least one preservative; and optionally at least one of an isotonicizing agent, a buffer or an excipient, wherein the formulation is free from or low in zinc. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY
This application claims the benefit under 35 U.S.C. § 120 of Provisional Applications 60/539,288 and 60/548,077, filed Jan. 26, 2004 and Feb. 26, 2004, respectively, and hereby incorporates both said Provisional Applications by reference.
FIELD OF THE INVENTION
The disclosed invention is directed to an athletic shoe, in particular a running shoe, having improved cushioning and energy returning properties that vary depending upon the speed of the runner due to incorporation of at least one insert containing dilatant compound encapsulated in a shell and set into the midsole of the running shoe.
BACKGROUND OF THE INVENTION
Shoes are generally intended to provide comfort and protection to the foot by fulfilling a number of functions related to the interface between the bottom of the foot and the surface on which the foot impacts during walking and running. Among these functions are: protection against cuts and abrasion; traction to prevent slipping; shock absorption to avoid injuries and bone and muscle damage that can be caused by repeated pounding of the foot against the walking or running surface; flexibility to allow natural body movements; cushioning for comfort; and the ability to behave elastically so that energy is conserved in walking and running.
Running shoes are shoes specifically made for running. Some running shoes are made for athletic competitions based on speed and endurance. Other running shoes are made for training for said competitions, as well as for non-competitive-related running for purposes such as exercise and fun. It is desirable during periods of actual competition to maximize the elastic behavior of a running shoe each time the runner's foot hits the ground, so as to conserve energy and provide a spring-like energy-returning effect with each step the runner makes and thereby assist the runner in achieving and sustaining higher speed, while nevertheless giving a level of cushioning and energy absorption suitable for comfort and injury and damage prevention. However, when running shoes are worn during periods when higher speed is less important, such as non-competitive running, walking, and jogging, it is desirable to maximize cushioning for comfort and shock absorption to prevent injury and damage. Moreover, it is desirable that all components of a running shoe be durable and lightweight.
Elasticity affects speed in two important ways. First, when the shoe behaves elastically, more energy is returned, and running becomes more efficient. It is known from physics that the fundamental, or resonant, frequency (F) of simple harmonic oscillator (a mass connected to a spring) is given by the expression,
F=A times square root ( K/M )
where A is a constant, K is elasticity of the spring, and M is the mass of the body. The amplitude of oscillation and energy efficiency is greatest at resonant frequency, and the above equation shows that the resonant frequency increases with increasing elasticity, and with decreasing weight. A runner's resonant frequency also increases in a similar way, so that as the shoes become more elastic, at a given weight the runner becomes more efficient at a faster pace.
According to Hooke's Law, elastic materials can be described in terms of a property known as the elastic modulus, that is, a linear relationship between applied force and the amount the materials deform. For a given level of applied force, low-modulus materials deform more than high-modulus materials. Running shoes that interpose low-modulus materials between the bottom of the foot and the walking and running surface are better for absorbing energy to provide cushioning and shock absorption. Running shoes that interpose high-modulus materials are better for storing elastic energy and returning it to the runner's foot as it lifts off the ground. Running shoes can be optimized for either cushioning and shock absorption on the one hand or speed on the other hand by control of the elastic modulus.
Accordingly, a great variety of running shoes and related devices is available on the market and described in prior art. Many running shoe components and materials are known which provide cushioning that attenuates and dissipates ground reaction forces. Prior art shoes have long incorporated a midsole composed of closed cell viscoelastic foams, such as ethyl vinyl acetate (“EVA”) and polyurethane (“PU”). EVA and PU are lightweight and stable foam materials that possess viscous and elastic qualities. The density or durometer, i.e., hardness, of EVA and PU can be altered by adjusting the manufacturing technique to provide differing degrees of cushioning. Alternate shoe structures for cushioning the impact of heel strike by incorporating gas or liquid or cushioning devices combinations thereof in chambers in the midsole are also well known. However, said running shoes and related devices are generally constructed of materials and in such a manner as to interpose materials having fixed elastic moduli between a runner's foot and the walking and running surface in order to achieve specific cushioning, shock absorbing and energy storing and returning properties.
Dilatant compounds are also well known. For purposes of this invention, a dilatant compound is a polymeric material that changes from soft and pliable under slow application of a load to elastic and bouncy under rapid application of a load. Technically, this means that a dilatant compound is a polymeric material whose yield point and elastic modulus increase with increasing strain rate. In other words, it is a liquid with inverse thixotropy, that is, a viscous liquid suspension that temporarily solidifies under applied pressure. Alternatively, it can be described as a liquid suspension in which the resistance to flow increases faster than the rate of flow.
A well-known example of a dilatant compound is the toy, Silly Putty® as described in U.S. Pat. No. 2,541,851. (Silly Putty is a registered trademark of Binney and Smith). Silly Putty® flows when slowly squeezed in the hand, but bounces when dropped on the floor. This behavior is known as strain-rate sensitivity. As shown in FIG. 7 , the material is soft and pliable under slow application of load, or slow strain rate. At faster application of load, or high strain rate, the material behaves elastically, as indicated by the steeper slope of the left-hand side of the fast-load response shown schematically on FIG. 7 .
Moreover, as shown in FIG. 7 , the yield point, i.e., the load at which the response changes from sloped (elastic) to horizontal (plastic) also increases at faster application of load. Since the amount of elastic energy stored is equal to the area beneath the elastic portion of the curve, it is evident that much more energy is stored during fast loading.
While it has been taught to interpose devices having variable elastic moduli between a runner's foot and the midsoles of running shoes so as to provide variable shock absorbing and cushioning properties, it has not been taught to provide midsoles that achieve higher energy storing and returning properties at higher running speeds.
SUMMARY OF THE INVENTION
Generally, the present invention describes an improved running shoe having a midsole with a modulus of elasticity and yield point that increase at higher running speeds.
In addition, the present invention describes a device that can be incorporated into the midsoles of existing running shoes to achieve higher energy storing and returning properties at higher running speeds.
Further, the present invention describes a method for incorporating said devices into the midsoles of existing running shoes so as to achieve higher energy storing and returning properties at higher running speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section of a shoe of the present invention.
FIG. 2 is a top view of a shoe midsole of the present invention.
FIG. 3 is an assembly drawing of a shoe of the present invention.
FIG. 4 is a fragmentary longitudinal cross section of a shoe midsole insert of the present invention.
FIG. 5 is a top view of a shoe midsole insert of the present invention.
FIG. 6 is a longitudinal cross section of a shoe of the present invention.
FIG. 7 is a chart showing how the elasticity of the material comprising the midsole insert of the present invention varies with the rate of application of the load on the material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and first more particularly to FIG. 1 , a running shoe of the present invention is indicated in its entirety by the reference numeral 2 . The shoe includes an outsole, generally indicated at 4 , and a midsole, generally indicated at 6 . Preferably, the outsole 4 is made of conventional durable material, such as carbon rubber, and the midsole 6 is made of a conventional cushioning material, such as foam PU or foam EVA. Other components of the running shoe include an upper 8 , which may be of leather or other conventional upper materials. The midsole has an upper surface 5 . An insole 3 , sometimes called a sock liner and constructed from conventional thin, flexible material such as fabric conventionally bonded to foam PU or EVA, preferably is interposed between the bottom of the runner's foot and the midsole upper surface 5 for enhanced comfort. Alternatively, the insole may be omitted without impairing the function of the present invention.
The midsole 6 receives compressive force either directly from the runner's foot or via the insole 3 when the runner is standing, walking or running.
Referring to FIG. 2 , the midsole 6 includes a forefoot region, generally indicated at 12 and a heel region, generally indicated at 14 . The midsole 6 includes at least one cavity 16 , preferably in the heel region 14 . Alternatively, the cavity is included in forefoot region 12 . Alternatively, one cavity is included in the heel region 14 in combination with one cavity that is included in the forefoot region 12 .
Referring to FIG. 3 , each cavity 16 has a continuous side wall 40 and a bottom wall 42 . Preferably each cavity 16 is sized and shaped for receiving an insert 18 filled with a dilatant compound, said insert 18 having been constructed to be substantially the same size and shape as the cavity 16 .
Referring to FIG. 4 , preferably insert 18 is generally cylindrical or disc-shaped and has an upper surface 19 that conforms to the contour of midsole upper surface 5 in order to provide a uniform support on which the user may place his or her heel without feeling any discontinuities. The cavity 16 preferably is cylindrical in order to receive and retain insert 18 . Insert 18 may be secured within cavity 16 with a suitable adhesive.
In the preferred embodiment, the dilatant compound is derived from a mixture of dimethyl siloxane, hydroxy-terminated polymers with boric acid, Thixotrol ST® brand organic rheological additive manufactured by Elementis Specialties, Inc., polydimethysiloxane, decamethyl cyclopentasiloxane, glycerine, and titanium dioxide. This compound is sold by Dow Corning as Dilatant Compound No. 3179. Other dilatant compounds that could be used are available on the market and described in the prior art.
Referring to FIG. 4 , the dilatant compound is preferably encapsulated fully, without air pockets or pockets of any other materials, in a shell that, when filled completely with the dilatant compound, will fit snugly into the cavity in the midsole. The shell comprises a bottom receptacle portion 30 into which the dilatant compound 32 is received and a top cover portion 34 that is attached to the bottom receptacle portion to seal in the dilatant compound. The bottom receptacle portion is a single piece having a bottom wall 36 , a continuous sidewall 38 molded upward a height H from the bottom wall to a top edge 40 , and a flange 42 molded outward from its inner perimeter 44 on the top edge to an outer perimeter 46 . The top cover portion 34 is a flat piece shaped substantially congruent to the outer perimeter of the flange 42 . The shell should be fabricated from material that is thin enough and flexible enough so as to permit immediate conformance of the dilatant compound-filled shell to the runner's foot and so that at any time the elastic modulus of the shell and the dilatant compound together will be insignificantly different from the elastic modulus of the dilatant compound alone. The shell should also be strong and durable enough so as not rupture upon the repeated application of pressures of up to 250 pounds per square inch. Preferably, the shell is made of polyurethane 0.007 inches thick. Preferably, for ease of manufacture, the shape of the bottom wall of the bottom receptacle portion is circular, the continuous sidewall is cylindrical having diameter D, and the outer perimeters of the flange and of the top cover piece are circular. Preferably, the width W of the flange is in a range between ⅛″ and ½″. Preferably, after the dilatant compound has been received into the bottom receptacle portion, the top cover piece is attached to the flange using radio frequency welding, which can be commercially accomplished by Polyworks LLC of North Smithfield, R.I. Upon manufacture as described above, the shell filled with dilatant compound together comprise the insert 18 . Other shapes of inserts may be conventionally constructed. It should be recognized that since the shell material is thin and flexible and the dilatant compound behaves as a viscous liquid in the absence of an applied force, the shape of the insert may vary from the as-constructed shape.
Preferably, the cavity 16 may be conventionally molded into the midsole during manufacture of the midsole. The cavity may also be carved into the midsole by conventional means. Preferred cylindrical cavities may be carved using a drill fitted with a commercially-available Forstner drill bit, the size of which drill bit is chosen to create a cylindrical cavity having, with reference to FIG. 3 , a diameter equal to the diameter D of the insert to be placed therein, and a depth equal to the height H of the continuous sidewall 36 of the bottom receptacle piece of the insert.
The insert is set into the cavity so that the bottom wall 36 and side wall 38 of the insert are in maximum contact with the bottom wall 42 and side wall 40 of the cavity. In setting the insert into the cavity, any gaps either between the side wall of the cavity and the side wall of the insert or the bottom wall of the insert and the bottom wall of the cavity or both are preferably filled with commercially-available elastomeric filler material such as Silicone II® brand 100% silicone sealant manufactured and sold by General Electric Company. Preferably, the insert is permanently retained in the midsole cavity using conventional adhesives to attach the bottom and side wall of the insert to the bottom and side wall of the cavity. The insert may also be permanently retained in the cavity by attaching the insole to the midsole upper surface 5 using conventional adhesives. The insert may also be removably set into the cavity and temporarily retained in the cavity by the pressure of the runner's foot in contact with the insole 3 or directly in contact with the midsole upper surface 5 and the top cover portion 34 of the insert.
Preferably, when pressure is initially applied from the runner's foot to the insert when the runner first stands in a shoe, the dilatant compound will be compressed against the bottom and side walls of the insert, thereby exerting pressure against the bottom and sides of the midsole cavity. Preferably, the midsole is constructed from a material with an elastic modulus lower than the elastic modulus of the dilatant compound after the dilatant compound has been subjected to the impact of fast running. Therefore, under slow application of force from the foot, as in walking or slow running, the dilatant compound deforms plastically (i.e., flows like a liquid) and transfers the foot's applied force to the surrounding midsole so that the dilatant and midsole together exhibit the low elastic modulus of the midsole material, thereby promoting cushioning and shock absorption. Under fast application of force, as in when the foot begins to impact against the insert during fast running, the dilatant compound will exhibit its inverse thixotropic properties and achieve a higher modulus of elasticity than the surrounding midsole; then, the insert will transfer less of the foot's impact force to the surrounding midsole, and instead will return more of the energy directly to the foot, thereby assisting in lift-off and increasing the runner's speed and energy efficiency.
On the one hand, it has been found that if the inner perimeter of the top edge 40 of the insert shell is larger than the perimeter of the portion of the runner's heel that exerts a degree of compressive impact on the insert necessary to cause the dilatant compound to exhibit its inverse thixotropic properties during running, portions of the dilatant compound will initially become relocated by “oozing” to portions of the insert outside said perimeter, so that exhibition of the inverse thixotropic properties does not occur or is significantly diminished, rather than remaining within the perimeter at the bottom of the runner's heel and receiving compressive impacts from the heel during running. In that case, the exhibition of the dilatant compound's inverse thixotropic properties in the packet during running will be diminished and the full benefits of the present invention will not be realized. On the other hand, if the inner perimeter of the top edge of the insert shell is smaller than the perimeter of the portion of the runner's heel that exerts a degree of compressive impact on the top wall of the insert necessary to cause the dilatant compound to exhibit its inverse thixotropic properties during running, the portions of the runner's heel that are outside said inner perimeter will exert compressive impact on the elastomeric, non-dilatant portions of the midsole. In that case, the full benefits of the present invention will not be realized. Preferably, the diameter D of each midsole insert would be custom fitted and fabricated based on the size and shape of the foot of the runner. Also preferably, the height H of the midsole insert would be custom fitted based on the thickness of the midsole. However, recognizing that such custom fitting and fabricating entails additional expense, I have found that a cylindrical insert in the heel region 14 having a diameter D of one and one half inches (1½″) and a height H of one-half inches (½″) provides substantially all of the benefits of the present invention in men's shoe sizes 5 through 13, which is equivalent to women's shoe sizes 6 through 14. Diameters varying from the preferred diameter by up to ⅛″ and heights varying from the preferred height by up to ⅛″ also provide substantially all of the benefits of the present invention.
The insert constructed of the size and shape described above and constructed of the materials described above incorporated into the midsole of the running shoe maximize shock absorption and comfort during walking, jogging, and slow running, while maximizing the elastic return of energy during fast running.
In an alternate embodiment of the invention, the dilatant compound is completely enclosed in one or more midsole chambers during manufacture of the midsole, using methods and materials of enclosure taught in the prior art. Referring to FIG. 6 , the midsole 26 includes at least one chamber 28 , preferably in the heel region 24 , or in the forefoot region 22 , or at least one chamber in each of the heel region and the forefoot region.
Many long distance runners are identified as heel strikers, meaning that they tend to land on the heel of the shoe. For this reason it is important that a midsole insert always be present beneath the heel. Other runners, particularly sprinters and short distance runners, tend to land on the forefoot. For these runners, a forefoot midsole insert of the present invention may be set in the forefoot region of the midsole. Similarly, using the methods described above, an insert of the present invention may be placed in the heel region of the midsole in combination with an insert of the present invention placed beneath the forefoot. The following examples illustrate the use of the present invention:
EXAMPLE 1
The rear midsole regions in a pair of worn out running shoes were cut open to expose gel pads beneath the heel. The gel pads were removed and replaced by midsole inserts consisting of packets of a dilatant compound, namely Silly Putty, wrapped in plastic. It was noted that the dilatant-compound midsole inserts restored the cushioning to the worn shoes to a level equal to or exceeding that of new shoes. The shoes were then used by a runner who trained at various speeds in a wide range of climatic conditions, and on a variety running surfaces for 100 miles. This trial demonstrated that a dilatant-compound midsole insert provides the combination of cushioning, shock absorption, and durability required for a running shoe.
EXAMPLE 2
The performance of shoes with dilatant-compound midsole inserts as described in Example 1 was compared to that of the identical shoes with the original gel pads replaced, and to that of a new pair of shoes with intact gel pads.
For purposes of this comparison, a 0.1-mile course was marked along a straight stretch of flat asphalt road. A runner was timed as he attempted to run as fast as possible while alternately wearing one of the three types of shoe. Between each sprint, the runner jogged back to the starting line and changed shoes for the next sprint. The three-way comparison was repeated a total of five times. As shown in Table 1, the average time for the shoe with the dilatant compound inserts (DC) was 1.29 seconds faster than the same shoe with its original gel pad replaced (Gel), and 1.83 seconds faster than the new shoe (NEW). These differences suggest improvements in mile times of 13 and 18 seconds, respectively. Statistical analyses (T-test) indicate that the probability that such differences could occur by chance is 2% or less.
TABLE 1
Time,
Time,
Time,
Difference,
Difference,
sec
sec
sec
sec
sec
Trial No.
DC
Gel
New
Gel-DC
New-DC
1
39.43
41.00
42.28
1.57
2.85
2
37.29
39.59
38.26
2.30
0.97
3
37.03
38.16
39.11
1.13
2.08
4
35.74
36.99
38.18
1.25
2.44
5
36.41
36.59
37.22
0.18
0.81
Total
185.90
192.33
195.05
6.43
9.15
Average
37.18
38.47
39.01
1.29
1.83
Std Dev
1.39
1.84
1.95
0.77
0.90
EXAMPLE 3
Six hundred pairs of various size running shoes with conventional foam EVA midsoles were factory produced using conventional manufacturing methods. Two pairs of size 11 shoes were selected at random, and carefully inspected for quality. A 0.5-inch-deep, 1.5-inch-diameter cavity was bored into the midsole beneath the heel regions of each shoe of one pair (Pair A). An insert constructed of dilatant compound encapsulated in a radio-welded 0.007 inch wall thickness polyurethane shell with the same dimensions as the cavity was set into the cavity of each shoe of Pair A using the methods described above. The second pair (Pair B) was left unchanged.
To compare the high-speed performance of Pairs A and B, a 0.1-mile course was marked along a downhill stretch of asphalt road. A runner was timed as he attempted to run the downhill segment as fast as possible while alternating shoes A and B. Between each sprint, the runner jogged back to the start, and changed shoes for the next sprint. This two-way comparison was repeated a total of eight times.
As shown in Table 2, the average time for the A shoes with the dilatant compound inserts of the present invention was 1.72 seconds faster than the B shoes without the dilatant compound insert. This result clearly demonstrates the speed-enhancing property of the dilatant compound midsole insert of the present invention. The magnitude of the difference suggests improvements in mile times of 18.9 seconds. Statistical analysis (T-test) indicates that this difference is real at a level of confidence greater than 99%.
TABLE 2
Difference, sec
Trial No.
Time, sec A
Time, sec B
A − B
1
34.52
35.01
0.49
2
34.29
36.34
2.05
3
31.97
35.66
3.69
4
33.47
34.12
0.65
5
31.11
34.17
3.06
6
32.34
33.28
0.94
7
31.00
33.49
2.49
8
30.12
31.84
1.72
Total
258.82
273.91
15.09
Average
32.35
34.24
1.89
Std Dev
1.61
1.43
1.16
The present invention has been described in terms of a preferred embodiment, it being understood that obvious modifications and additions to this preferred embodiment will become apparent to those skilled in the relevant art upon a review of this disclosure. It is intended that all such obvious modifications and additions be covered by the present invention to the extent that they are included with the scope of the several claims appended hereto. | An athletic shoe, in particular a running shoe, having improved cushioning and energy returning properties that vary depending upon the speed of the runner due to incorporation of at least one insert containing dilatant compound encapsulated in a shell and set into the midsole of the running shoe is disclosed. A method for converting the midsole of an existing running shoe is also disclosed. | 0 |
FIELD OF THE INVENTION
This invention relates to a metathesis polymerized cross-linked copolymer, a process for producing the copolymer, a process for producing a molded article from the copolymer, a polymerizable composition used for producing the copolymer and the molded article and a molded article produced from the copolymer.
BACKGROUND OF THE INVENTION
It is disclosed in Japanese Patent Laid Open Sho 53-24400, U.S. Pat. No. 4,400,340 and U.S. Pat. No. 4,426,502 that ring-opening polymerization of a cycloolefin containing norbornene moiety, e.g. dicyclopentadiene (called "DCP" hereinafter), in the presence of a metathesis polymerization catalyst system produces a cross-linked polymer containing olefinic groups in the main chain.
Said Japanese Patent Laid Open Sho 53-24400 is characterized by per se a new metathesis catalyst system, and in it, polymerization of DCP, etc. is accomplished in the presence of a hydrocarbon solvent. DCP polymer prepared therein is recovered from the solvent and then is used to produce a molded article. This means that DCP polymer prepared by using the catalyst system is substantially no-crosslinked non-heat-resistant thermoplastics having a low softening point.
Said U.S. Pat. No. 4,400,340 and U.S. Pat. No. 4,426,502 disclose the production of a molded article by injecting a reactive liquid mixture comprising norbornenetype monomer such as DCP and a metathesis polymerization catalyst system into a mold in which said liquid mixture is metathesis polymerized in bulk (called "RIM process" hereinafter). RIM process is a low pressure one-step or one-shot injection of a liquid mixture into a closed mold where rapid polymerization occurs resulting in a molded article. Thus, there are easily produced large-sized molded articles from DCP and the like by RIM process. The molded articles have been taken notice from the industrial point of view since they have attractive physical properties as balanced in stiffness and impact resistance. However, the molded articles produced from DCP by said RIM process have low softening points generally below 120° C., and this often limits the use of the molded articles produced from DCP, etc.
Further, Japanese Patent Laid Open Sho 61-179214 discloses metathesis copolymerization of norbornene-type cycloolefins such as DCP with other metathesis polymerizable comonomers to produce copolymers having relatively high glass transition temperatures. However, in this case, the attained increase of glass transition temperature is at most about 50° C. and is not enough.
Now, we have found that a mixture comprising the following monomers: ##STR2## or a mixture comprising the following monomers: ##STR3## is readily metathesis polymerized or readily metathesis copolymerized with norbornene-type cycloalkene such as DCP to produce highly cross-linked heat resistant copolymers having a very high softening point.
The mixture comprising the monomers (I-a) and (I-b) is readily obtained as a Diels-Alder adduct of 2 moles of cyclopentadiene with 1 mole of cyclooctadiene. The monomers (I-a) and (I-b) are produced simultaneously in said Diels-Alder reaction, and have the same molecular weight, and arc not easily separable from each other by usual separation methods such as fractional distillation. Therefore, in the present invention, the mixture of the monomers (I-a) and (I-b) is used.
The mixture comprising the monomers (II-a) and (II-b) is readily obtained as a Diels-Alder adduct of 2 moles of cyclopentadiene with 1 mole of 1,5-hexadiene. The monomer (II-a) and monomer (II-b) have a1so the same molecular weight and are not easily separable, and are used as a mixture of them.
Cyclooctadiene and 1,5-hexadiene, the starting materials of the monomers (I-a) and (I-b) or (II-a) and (II-b), are commercially available petrochemical derivatives as well as cyclopentadiene sources.
Therefore, it is an object of the present invention to provide a highly cross-linked heat resistant metathesis polymerized copolymer which is readily and cheaply produced from petroleum products.
A further object is to provide a process for producing said copolymer. Another object is to provide a process for producing a molded article comprising the copolymer. A further object is to provide a polymerizable composition used for producing copolymer and the molded article. Another object is to provide a molded article.
SUMARRY OF THE INVENTION
The present invention relates to a metathesis polymerized cross-linked copolymer comprising:
(a) 3-100 mole % of repeating units derived from a mixture comprising the following monomers: ##STR4## or a mixture comprising the following monomers: ##STR5## and (b) 97-0 mole % of repeating units derived from at least one of metathesis polymerizable cyclic compounds.
Further, the present invention relates to a process of producing the cross-linked copolymer which comprises metathesis polymerizing in the presence of a metathesis polymerization catalyst system a monomer mixture comprising:
(a) 3-100 mole % of the mixture comprising the monomers (I-a) and (I-b) or the mixture comprising the monomers (II-a) and (II-b), and
(b) 97-0 mole % of at least one of metathesis polymerizable cyclic compounds.
In addition, the present invention relates to a process for producing a molded article by introducing a reactive liquid mixture which comprises 3-100 mole % of said metathesis polymerizable mixture (a) and 97-0 mole % of the cyclic compounds (b), and a metathesis polymerization catalyst system into a mold in which said liquid mixture is metathesis polymerized in bulk to produce the molded article.
The present invention further relates to a multi-part polymerizable composition, which comprises 3-100 mole % of said metathesis polymerizable mixture (a), and 97-0 mole % of the cyclic compounds (b), and the metathesis polymerization catalyst system comprising a catalyst and an activator, said catalyst and activator being not present in the same part.
The present invention further provides a molded article produced from said copolymer.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, as the comonomers (a), there is used the mixture comprising the monomers (I-a) and (I-b) (called "M-I" hereinafter) or the mixture comprising the monomers (II-a) and (II-b) (called "M-II" hereinafter) in the range of 3-100 mole %, preferably 3-80 mole %, more preferably 5-50 mole %, most preferably 10-35 mole % based on total moles of the monomers (a) and the cyclic compounds (b).
The copolymerization of at least 3 mole % of M-I and M-II with DCP provides highly cross-linked heat resistant copolymer having a high softening point, generally, of over 150° C.
For example, the copolymerization of 30 mole % of M-I with 70 mole % of DCP provides a copolymer having a softening point above 190° C., and the copolymerization of 30 mole % of M-II with 70 mole % of DCP provides a copolymer having a softening point above 170° C. In general, softening points of the copolymers of M-I or M-II with DCP are over 50° C. higher than the softening point of the original DCP homopolymer.
The monomer (I-a) contained in M-I is called 1,4,4a,5,6,6a,7,10,10a,11,12,12a-dodecahydro-1,4,7,10-dimethanodibenzo(a,e)cyclooctene (called "DDDCO" hereinafter), and the monomer (I-b) contained in M-I is called 1,4,4a,5,5a,11a,12,12a-octahydro-1,4,5,12-dimethano-5H-naphthocyclooctene (called "ODNCO" hereinafter). Both of DDDCO and ODNCO have two metathesis polymerizable cycloolefinic groups and have more bulky, rigid structure than DCP, from which it is presumed that such structural characteristics provide the copolymers with high softening temperatures.
M-I contains DDDCO and ODNCO in a molar ratio of about 1:1 when determined by gas-chromatography. On the other hand, the monomer (II-a) contained in M-II is called ethylene-bis (norbornene) (called "EBN" hereinafter), and the monomer (II-b) is called 6-butene-3-yl1,4,5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene (called "BDON" hereinafter).
EBN has two very readily methathesis-polymerizable norbornene groups, and BDON has a bulky and rigid dimethano octahydronaphthalene group. The combination of the characteristic of EBN and BDON provides the copolymers with very high softening temperatures.
M-II contains EBN and BDON in a molar ratio of about 1:1 when determined by gas-chromatography.
In the above determination of the molar ratio, DDDCO, ODNCO, EBN and BDON can be identified by the gaschromatography mass spectrum measurement.
Among M-I and M-II, M-I is generally more preferable than M-II, since cyclooctadiene used to produce M-I is generally less expensive than 1,5-hexadiene used to produce M-II and the acyclic olefinic group contained in BDON often shows, in the metathesis polymerization, a chain-transferring function, which decreases the molecular weight of the copolymer.
It is well known that cyclopentadiene is converted spontaneously to DCP under a room temperature and DCP can decompose to cyclopentadiene when heated. Therefore, DCP may be used as a precursor of cyclopentadiene in the Diels-Alder reaction to produce M-I and M-II, in which case the Diels-Alder reaction is generally carried out at about 125°-250° C.
From the stoichiometric view point, it is presumed that the Diels-Alder reaction to produce M-I or M-II can be effectively carried out by mixing cyclopentadiene with cyclooctadiene or 1,5-hexadiene in the molar ratio of about 2:1. In this case, however, oligocyclopentadienes such as tricyclopentadiene was found to be formed predominantly with negligible amount of M-I or M-II.
Now, it was found that the use of an excessive amount of cyclooctadiene or 1,5-hexadiene, for example 5 moles of cyclooctadiene or 1,5-hexadiene per 1 mole of cyclopentadiene, was advantageous to the production of M-I or M-II.
In the practice of the invention, therefore, it is preferred that, in the production of M-I or M-II, the molar ratio of cyclooctadiene or 1,5-hexadiene to cyclopentadiene is about 10:1-1000:1.
In the present invention, M-I including DDDCO and ODNCO is produced according to the following two-steps reaction: ##STR6## and further, M-II including EBN and BDON is produced according to the following two-steps reaction: ##STR7## By the Diels-Alder reaction of cyclopentadiene with cyclo-octadiene or 1,5-hexadiene, there are produced 1:1 aducts of cyclopentadiene with cyclooctadiene or 1,5-hexadiene cyclopentadiene oligomers, e.g. tricyclopentadiene, tetracyclopentadiene, and the like together with the above M-I and M-II. Therefore, according to the gas-chromatography mass spectrum identification, the products by the Diels-Alder reaction of cyclopentadiene with cyclooctadiene include various compounds shown in Table 1 below and the like when not purified.
TABLE 1__________________________________________________________________________ Number of carbon atom__________________________________________________________________________ ##STR8## cyclopentadiene C.sub.5.sub. ##STR9## cyclooctadiene C.sub.8.sub. ##STR10## DCP C.sub.10 ##STR11## 1,4-methanol-1,4-dihydro- 5H-benzocyclooctene (called "MDB" hereinafter) C.sub.13 ##STR12## cyclopentadiene-trimers (called "tri-CP" hereinafter) C.sub.15 ##STR13## ##STR14## C.sub.18Cyclopentadiene tetramer C.sub.20(called "tetra-CP" hereinafter)3:1 Adducts of cyclopentadiene and C.sub.23cyclooctadiene__________________________________________________________________________
On the other hand, the products by the Diels-Alder reaction of cyclopentadiene with 1,5-hexadiene include various compounds shown in Table 2 below and the like when not purified.
TABLE 2__________________________________________________________________________ Number of carbon atom__________________________________________________________________________ ##STR15## cyclopentadiene C.sub.5.sub.CH.sub.2CHCH.sub.2 CH.sub.2 CHCH.sub.2 1,5-hexadiene C.sub.6.sub. ##STR16## DCP C.sub.10 ##STR17## 5-(butene-3-yl)norborene (called "BNB" hereinafter) C.sub.11 ##STR18## cyclopentadiene-trimers (called "tri-CP" herein- after) C.sub.15 ##STR19## ##STR20## C.sub.16Cyclopentadiene-tetramer C.sub.20(called "tetra-CP" hereinafter)3:1 Adducts of cyclopentadiene and C.sub.23cyclooctadiene__________________________________________________________________________
Among of the above compounds, cyclopentadiene, cyclooctadiene, 1,5-hexadiene, DCP, MDB and BNB, which have lower boiling points than M-I and M-II, can be readily distilled off from other compound having higher boiling points, e.g. M-I, M-II and the like MDB and BNB, however, are metathesis copolymerizable with M-I, M-II and the like, and they may be used as comonomers in the present invention. Cyclopentadiene-oligomers, especially tri-CP and tetra-CP may also be used as comonomers when they remain unseparated.
In the metathesis polymerization of the present invention, it is preferred that M-I, M-II or monomer mixtures containing M-I or M-II contains as small polar impurities as possible, since the polar impurities having polar group such as hydroxyl-, carboxyl-, carbonyl-, peroxide groups and the like may inhibit metathesis polymerization.
In the present invention, cross-linked copolymers consisting essentially of M-I or M-II can be produced when thoroughly purified M-I or M-II is solely used. As mentioned above, however, M-I or M-II is generally produced as a mixture with unreacted starting materials such as cyclopentadiene, DCP, cyclooctadiene, 1,5-hexadiene and the like, 1:1 adducts, i.e. MDB and BNB, cyclopentadiene oligomers such as tri-CP and tetra-CP, and higher adducts, some of which arc easily unseparable from M-I or M-II and are metathesis polymerizable.
From the view points of economy and process operations, therefore, DCP, cyclopentadiene-oligomers such as tri-CP and tetra-CP, MDB and BNB are preferably used with M-I or M-II as the metathesis cyclic compounds (b) in the present invention. Among of them, DCP is most preferable since it is inexpensively available as a petroleum product.
In the present invention, the metathesis compounds (b) is preferably used in the range of 97-20 mole %, more preferably 95-50 mole %, most preferably 90-65 mole %, based on total moles of the monomers (a) and the cyclic compounds (b).
It is preferred that the cyclic compounds (b) contain at least 30 mole %, preferably 50 mole %, more preferably 85 mole %, based on total moles of the cyclic compounds (b), of at least one of DCP, cyclopentadieneoligomers such as tri-CP and 1:1 adducts such as MDB or BNB. More preferably, DCP is used in at least 30 mole %, more preferably 95-50 mole % based on the total moles of the cyclic compounds (b).
Higher adducts formed in the synthesis of M-I or M-II can also be used as the cyclic compounds (b).
In the present invention, there may also be used at least one of metathesis polymerizable compounds other than above mentioned DCP, MDB, BNB, cyclopentadieneoligomers, the higher adducts and the like. Among of them are included cyclic compounds, which have at least one norbornene-moiety and are easily available as petroleum products, such as cyclopentadiene-methylcyclopentadiene codimer, ethylidene norbornene, norbornene, norbornodiene, 1,4,5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4,5,8-dimethano-1,4,4a,5,6,7,-8,8a-octahydronaphthalene, and 1,4,5,8-dimethano-1,4,4a-5,8,8a-hexahydronaphthalene.
As mentioned above, the copolymerization of M-I or M-II with those cyclic compounds (b) provides the copolymer with high softening points compared with the polymers produced from only the cyclic compounds (b).
In the present invention, as the cyclic compounds (b), there may also be used those having at least one of hetero atom such as oxygen, nitrogen and the like together with metathesis polymerizable cycloalkene moiety, preferably norbornene moiety.
The hetero atom forms a polar group in the structure of said cyclic compounds, and the polar group often can moderate the metathesis polymerization reaction.
Examples of the polar groups having such moderation effect preferably include ether groups, carboxylic ester groups, cyano group, N-substituted imido groups and the like.
The monomers having such polar groups are preferably used in such amount that the desired moderation effect is achieved, and generally are used in the proportion of up to 10 mole % based on total moles of the monomers (a) and cyclic compounds (b).
Examples of the cyclic compounds having the polar groups include [(5-norbornenyl)-methyl]phenyl ether, bis [(5-norbornenyl)-methyl]ether, 5-methoxycarbonylnorbornene, 5-methoxycarbonyl-5-methylnorbornene, 5-[(2-ethylhexyloxy)carbonyl]norbornene, ethylene-bis(5-norbornenecarboxylate), 5-cyanonorbornene, 6-cyano-1,4,5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, N-butylnadic acid imide, 5-(4-pyridyl)norbornene and the like.
Among the exmaples, 5-methoxycarbonylnorbornene, 5-methoxycarbonyl-5-methylnorbornene, 5-cyanonorbornene and N-butylnadic imide are preferred, since they are easily available.
In general, as well known, the metathesis polymerization catalyst system is composed of two components, i.e. a main catalyst component and an activator component. In the practice of bulk polymerization in the presence of the metathesis polymerization catalyst system, the activator component is first added to the monomer mixture and then the principal catalyst component is added to the mixture to initiate polymerization and finally the mixture is molded before solidified to produce a cross-linked molded articles. Alternatively, the principal catalyst component and the activator component can be added to the monomer mixture in reversed order. Further, the principal catalyst component and the activator component are simultaneously added to the monomer mixture immediately before pouring the mixture into the mold and molded articles are prepared in the same manner as the above.
The metathesis polymerization reaction, however is an exothermal reaction and proceeds very rapidly. Under such situation, the polymerization often occurs before the mixture poured into a mold, and it makes the pouring of the mixture into the mold difficult and makes the production of large sized molded articles difficult.
Accordingly, it is desirable to use a method in which the original reactive monomer solutions to be poured into the mold are separated into multi-part reactive solutions, that is, the catalyst and the activator of the metathesis polymerization catalyst system are added to individual monomer liquids to form multi-part reactive solutions, and then the multi-part reactive solutions are mixed rapidly by means of impingement-mixing (the RIM process) or by using a static mixer, and finally the mixture is immediately poured into a mold wherein it is polymerized and molded.
In this method, the multi-part reactive solutions do not need to have the same proportion of monomers each other. The proportion of the monomers may be changed freely provided that the whole proportion of the monomers is kept within the above-mentioned range. For example, when a polar monomer moderating the metathesis polymerization is used with DCP and M-I or M-II, it is preferable that the content of the polar monomer is higher in the reactive solution where the moderator can act more effectively.
As the catalyst component of the metathesis polymerization catalyst system are used salts such as halides of tungsten, molybdenum, rhenium or tantalium, preferably, tungsten and molybdenum. Particularly preferable are the tungsten compounds. Among tungsten compounds are preferred tungsten halides, tungsten oxyhalides and the like. More particularly, tungsten hexachloride and tungsten oxychloride are preferred. Organo ammonium tungstate may also be used. However, such halogen-containing tungsten compounds undesirably often initiate cationic polymerization immediately when added directly to the mixture of monomers. It is, therefore, preferable that they are previously suspended in an inert solvent such as, for example, benzene, toluene or chlorobenzene and solubilized by the addition of an alcoholic compound or a phenolic compound.
A chelating agent or a Lewis base is preferably added to the solution containing the tungsten compound in order to prevent undesirable polymerization. Those additives may include acetylacetone, acetoacetic acid, alkyl esters, tetrahydrofuran, benzonitrile and the like. About 1-5 moles of a chelating agent or the Lewis base is preferably used per one mole of the tungsten compound. However, when a polar monomer moderating the metathesis polymerization is used with DCP and M-I or M-II, the chelating agent or the Lewis base may be omitted. Under such situations, the reactive solution containing the monomers and the catalyst component of the metathesis polymerization catalyst system is kept stable sufficiently for practical use.
The activator components of the metathesis polymerization catalyst system include organic metal compounds such as alkylated products of metals of Group I - Group III in the Periodic Table, preferably, tetraalkyl tins, alkylaluminum compounds and alkylaluminum halide compounds including diethylaluminum chloride, ethylaluminum dichloride, trioctylaluminum, dioctylaluminum iodide, tetrabutyltin and the like. The activator component is dissolved in a mixture of monomers to form the other reactive solution.
According to the present invention, in principle the molded articles are produced by mixing said two reactive solutions as already described above. The polymerization reaction, however, starts so rapidly when above-mentioned composition is used, and so the undesirable initiation of polymerization often accompanied by partial gelling occurs before completion of filling of the mixed solution into the mold. In order to overcome the problem, it is preferable to use a polymerization moderating agent.
As such moderators are generally used Lewis bases, particularly, ethers, esters, nitriles and the like.
Examples of the moderators include ethylbenzoate, butyl ether, diglyme, diethyleneglycoldibutylether, benzonitrile and the like. Such moderators are generally added to the reactive solution containing the activator component.
In this case, when a polar monomer moderating the metathesis polymerization is used with DCP and M-I or M-II in the reactive solution containing the activator component, the Lewis base may also be omitted.
When a tungsten compound is used as the catalyst component, the ratio of the tungsten compound to the above-mentioned monomers is about 1000:1--about 15000:1, and preferably about 2000:1 on molar base. When an alkylaluminum compound is used as the activator component, the ratio of the aluminum compound to the above-mentioned monomers is about 100:1--about 2000:1 and preferably around a ratio of about 200:1--about 500:1 on molar base. The amount of the masking agent or the moderator may be adjusted by experiments depending upon the amount of the catalyst system.
A variety of additives may be used practically in the present invention to improve or to maintain characteristics of the molded articles. The additives include fillers, reinforcing agents, pigments, antioxidants, light stabilizers, macromolecular modifiers, flame retardants and the like. These additives must be added to the starting solutions, since they cannot be added after the solutions are polymerized to the solid molded polymer.
They may be added to either one or both of multi-part reactive solutions. The additives must be ones being substantially unreactive with the highly reactive catalyst or activator component in the solution to avoid troubles as well as not to inhibit polymerization.
If a reaction between the additive and the catalyst is unavoidable but does not proceed so rapidly, the additives can be mixed with the monomers to prepare a third solution, and the third solution is mixed with the first and/or second solutions of the multi-part solutions immediately before pouring the mixture into a mold. When the additive is a solid filler, a reactive solution containing the filler suspended in it can be used. Instead, the mold can be filled with the filler prior to pouring the reactive solutions into the mold.
The reinforcing agents and fillers can improve flexural modulus of the polymer. They include glass fibers, mica, carbon black, wollastonite and the like. The fillers whose surfaces are treated with silan coupling agent may preferably be used.
The molded articles of the invention may preferably contain an antioxidant. Preferably, a phenolor amine-antioxidant is added in advance to the polymerizable solution. Examples of the antioxidants include 2,6-t-butyl-p-cresol, N,N'-diphenyl-p-phenylenediamine, tetrakis-[methylene(3,5-di-t-butyl-4-hydroxycinnamate)]methane, methylene-4,4'-bis(3,5-di-t-butylphenol) and the like.
The polymer molded articles of the invention may also contain other polymers, which are added to the monomer solution. Among polymers, elastomers are more preferable since they increase the impact strength of the molded articles and they effectively controll the viscosity of the solution. Examples of the elastomers include styrenebutadiene rubber, polybutadiene, styrene-butadiene-styrene triblock rubber, styrene-isoprene-styrene triblock rubber, polyisoprene, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene terpolymers, nitril rubber and the like.
As described above, the polymer molded articles of the invention are preferably prepared by simultaneous molding with polymerizing, i.e. by RIM process or pre-mix process including RTM and RI process. In RIM process, two-part monomer solutions containing the catalyst and the activator respectively are rapidly mixed in the mixing head of a RIM instrument and the mixture is poured into a mold wherein it polymerizes and is molded.
In pre-mix process, two-part monomer solutions containing the catalyst component and the activator component respectively are previously mixed to prepare a pre-mixture and then the pre-mixture is introduced into a mold. In the pre-mix process, fillers such as glass fibers may be placed in the mold prior to pouring the pre-mixture, or may be added in the pre-mixture.
In both of RIM process and pre-mix process, the mixture can be introduced into the mold under relatively low pressure so that an inexpensive mold is usable. The temperature inside the mold increases rapidly by heat of the polymerization reaction so that the polymerization reaction is completed in a short time. The molded article of the invention can be removed easily from the mold without a releasing agent unlike the polyurethan-RIM process.
The surface of the molded articles of the invention has polarity probably by the oxidized layer formed on the surface so that conventional coatings such as epoxy, polyurethane and the like adhere to the surface well.
The present invention provides a variety of molded articles which include large sized molded articles such as parts of various vehicles including automobiles, motorbikes, motorboats, snowmobiles, etc. and housing of electric and electronic instruments and the like.
In the present invention, the metathesis copolymerizaton of M-I or M-II with DCP and occasionally other monomer produces highly cross-linked copolymers being highly heat-resistant based on their high softening points of, generally, over 150° C. Therefore, the molded articles produced from said copolymers are also highly heat-resistant and are practically usable in many field.
Further, because both of said M-I and M-II used in the present invention are readily and cheaply producible or available from petroleum products, the copolymers and molded articles are easily and cheaply produced. Especially, copolymers of M-I or M-II with DCP are usable in many applications.
The invention described herein is illustrated by the following examples These examples do not limit the invention.
EXAMPLES 1-5 AND COMPARATIVE EXAMPLE
[Preparation of monomers]
3000 g Of cyclooctadiene, 300 g of DCP and 2 g of hydroquinone were charged into a 10 l. autoclave purged with nitrogen and then were reacted at 180° C. for three hours. The gas-chromatography analysis of the content showed that the amount of DCP decreased to one tenth of initially charged amount of DCP. Then, fine 300 g portions of DCP were further added to the above reaction mixture in the autoclave at 180° C. at intervals of three hours over the period of 15 hours. There was prepared a mixture containing 56 wt.% of cyclooctadiene, 2 wt.% of DCP, 21 wt.% of MDB, 5 wt.% of tri-CP and 15 wt.% of M-I. The gas-chromatography analysis showed that said 15 wt.% of M-I consisted of 8 wt.% of DDDCO and 7 wt.% of ODNCO.
The mixture was then distilled under reduced pressure to distill off cyclooctadiene and DCP and to prepare a concentrated mixture containing 41 wt.% of MDB, 14% of tri-CP and 45 wt.% of M-I. The concentrated mixture was further distilled at a higher temperature under more reduced pressure to prepare a more concentrated mixture (called "Mixture- ○1 " hereinafter) containing 14 wt.% of tri-CP, 2 wt.% of tetra-CP and 84 wt.% of M-I. The gas-chromatography analysis showed that said 84 wt.% of M-I consisted of 46 wt.% of DDDCO and 38 wt.% of ODNCO.
[Preparation of mixed monomer solutions]
Commercially available dicyclopentadiene (DCP) was purified by distillation under nitrogen and reduced pressure to produce purified DCP with a freezing point of 33.4° C. The purity was determined by gas-chromatography to be not less than 99%.
DCP, said Mixture- ○1 and occasionally an other third comonomer were mixed in the weight % shown in Table 3 below to prepare mixed monomer solutions. Table 3 also shows mole % of monomers in the mixed monomer solutions together with the weight proportions of monomers.
[Preparation of solutions containing the catalyst]
20 g Of tungsten hexachloride was added to 70 ml of anhydrous toluene under nitrogen and then a solution consisting of 21 g of nonylphenol and 16 ml of toluene was added to prepare a catalyst solution containing 0.5M tungsten in terms of the metal content. The solution was purged with nitrogen overnight to remove hydrogen chloride gas formed by the reaction of tungsten hexachloride with nonylphenol. The resulting solution was used as a catalyst solution for polymerization.
With 10 ml of the above catalyst solution were mixed 1.0 ml of acetylacetone and a given amount of each of the mixed monomer solutions shown in Table 3 to prepare the first reactive solution (Solution A) containing 0.001 M tungsten in terms of the metal content.
[Preparation of solutions containing activator]
Trioctylalminum, dioctylaluminum and diglyme were mixed in the molar ratio of 85:15:300 to prepare an activator solution. The activator solution was mixed with a given amount of each of the mixed monomer solutions shown in Table 3 to prepare the second reactive solution (Solution B) containing 0.003M aluminum in terms of the metal content.
Each of 10 ml of Solution A and 10 ml of Solution B was introduced into two syringes respectively after being kept at a given temperature shown in Table 3 below and thoroughly purged with nitrogen. The solutions in each syringe were rapidly introduced into a glass-flask equipped with a stirrer and were mixed rapidly. Then, the stirrer was removed and a thermo-couple was inserted. There was measured the time at which the reaction mixture reached at 100° C. after the introduction from the syringes (called "polymerization time" hereinafter).
There was produced each of cross-linked molded articles, and it was cut into test pieces. The softening point of each test piece was measured according to the TMA method as well as the degree of swelling in toluene which is an indication of the chemical resistance of the polymer.
TABLE 3__________________________________________________________________________ ComparativeExample No. Example 1 Example 1 Example 2 Example 3 Example 4 Example__________________________________________________________________________ 5Wt. % of monomers in the mixedmonomer solution (wt. %)DCP 100 84 57 36 79 78Mixture- ○1 0 16 43 64 16 16 MM-1.sup.(1) MM-2.sup.(2)the third comonomer 0 0 0 0 5 5Mole % of monomers in the mixedmonomer solutions (mole %)DCP 100 90 70 50 85 85M-I 0 8 25 41 8 8tri-CP 0 2 5 8 2 2tetra-CP 0 0 1 1 0 0 MM-1 MM-2the third comonomer 0 0 0 0 5 5Initial temp. when mixed (°C.) 35 36 50 100 35 35Polymerization time reaching 22 25 60 88 24 60100° C. (sec.)TMA softening point (°C.) 93 152 194 195 150 140Degree of swelling.sup.(3) 1.62 1.73 1.40 1.39 1.78 1.75__________________________________________________________________________ .sup.(1) MM-1: 5ethylidene-norbornene .sup.(2) MM-2: 5methoxycarbonylnorbornene .sup.(3) Samples were immersed in toluene for one day. Then, the weight ratio of the swelled samples to the originals was measured.
Table 3 shows that the softening points of polymers dramatically rise with the increase of the amount of M-I copolymerized.
Table 3 also shows that the copolymerization of small amount of M-I with DCP provides the polymers with higher degree of swelling, i.e. lower degree of cross-linking of the polymers as compared with DCP homopolymer and that, on the other hand, the copolymerization of large amount of M-I with DCP provides the polymers with lower degree of swelling, i.e. higher degree of cross-linking of the polymers as compared with DCP homopolymer.
Each of 10 ml of Solution A and 10 ml of Solution B of Example 1 was introduced into two syringes respectively kept at 25° C. and thoroughly purged with nitrogen. The solutions in each syringe were injected at a constant rate into a mold of a miniature-sized RIM instrument in which nozzle the solutions were mixed. A very strong brown molded plate was produced.
5 ml Of Solution A and 5 ml of Solution B of Example 3 was mixed and stirred under nitrogen stream to prepare a pre-mixture, and then the pre-mixture was cast into a mold maintained at 90° C. A very strong brown molded plate was produced.
EXAMPLES 11-12
[Preparation of monomers]
45 g Of 1,5-hexadiene and 36 g of DCP were charged into a 200 ml autoclave purged with nitrogen and then were reacted at 190° C. for eight hours. The gas-chromatography analysis of the product showed that it was a mixture containing 16 wt.% of 1,5-hexadiene, 9 wt.% of DCP, 12 wt.% of BNB, 27 wt.% of tri-CP and 25 wt.% of M-II. The mixture was distilled under reduced pressure to prepare a mixture (called "Mixture- ○2 " hereinafter) containing 49 wt.% of M-II and 50 wt.% of tri-CP. The gas-chromatography analysis of M-II showed that said M-II in Mixture- ○2 contained EBN and BDON in the molar ratio of 52:48.
[Preparation of mixed monomer solutions]
Commercially available dicyclopentadiene (DCP) was purified by distillation under nitrogen and reduced pressure to produce purified DCP with a freezing point of 33.4° C. The purity was determined by gas-chromatography to be not less than 99%.
DCP, said Mixture- ○2 and occasionally an other third comonomer were mixed in the weight % shown in Table 4 below to prepare mixed monomer solutions. Table 4 also shows mole % of monomers in the mixed monomer solutions together with the weight proportion of monomers.
Reactive Solutions A and B were prepared according to the same procedures as Examples 1-5 under using the same catalyst solution and the same activator solution as used in Examples 1-5.
Cross-linked molded articles were produced by mixing Solution A and Solution B and then molding the mixture in the same manner as Examples 1-5.
Polymerization time, TMA softening point and degree of swelling of the molded articles were measured in the same manners as Examples 1-5. The results are shown in Table 4 below.
TABLE 4__________________________________________________________________________Example No. Example 6 Example 7 Example 8 Example 9 Example 10 Example Example__________________________________________________________________________ 12Wt. % of monomers in the mixedmonomer solution (wt. %)DCP 0 15 11 41 36 61 86Mixture- ○2 100 85 86 59 57 39 14 MM-1.sup.(1) MM-3.sup.(3)the third comonomer 0 0 3 0 7 0 0Mole % of monomers in the mixedmonomer solutions (mole %)DCP 0 20 15 50 45 70 90M-II 50 40 40 25 25 15 5tri-CP 50 40 40 25 25 15 5 MM-1 MM-3the third comonomer 0 0 5 0 5 0 0Initial temp. when mixed (°C.) 35 35 35 35 35 35 35Polymerization time reaching 30 31 28 30 27 26 23100° C. (sec.)TMA softening point (°C.) 180 199 189 186 186 174 169Degree of swelling.sup.(3) 1.50 1.41 1.43 1.31 1.35 1.43 1.50__________________________________________________________________________ .sup.(1)MM-1: 5ethylidene-norbornene .sup.(2)MM-2: methylcyclopentadienecyclopentadiene codimer
Table 4 shows that the copolymerization of M-II with DCP provides the copolymers with dramatically rised softening points and decreased degrees of swelling even if a small amount of M-II is copolymerized with DCP.
EXAMPLES 13-14
45 g Of 1,5-hexadiene and 5 g of DCP were charged into a 200 ml autoclave purged with nitrogen and then were reacted at 180° C. for three hours.
The gas-chromatography analysis of the content showed that the amount of DCP decreased to one tenth of initially charged amount of DCP.
Then fine 5 g portions of DCP were further added to the above reaction mixture in the autoclave at 180° C. at intervals of four hours over the period of 20 hours.
Among of said two sets of reactive solutions, one set consisted of 100 wt.% of Mixture- ○3 (Example 13) and the other set consisted of 10 wt.% of Mixture- ○3 and 90 wt.% of DCP (Example 14).
Cross-linked molded articles were produced by mixing Solution A and Solution B and then molding the mixture in the same manner as Examples 1-5.
The molded article of Example 13 had the softening point of 190° C., and the molded article of Example 14 had the softening point of 151° C.
There was prepared a mixture containing 33 wt.% of 1,5-hexadiene, 17 wt.% of BNB, 1 wt.% of tri-CP and 49 wt.% of M-II. The gas-chromatography analysis of M-II showed that M-II contained EBN and BDON in the molar ratio of 52:48.
The mixture was then distilled under reduced pressure to distill off compounds having low boiling point and to prepare a concentrated mixture (called "Mixture- ○3 " hereinafter) containing 97 wt.% of M-II and 3 wt.% of tri-CP.
Two sets of Reactive Solutions A and B were prepared according to the same procedures as Examples 1-5 under using the same catalyst solution and the same activator solution as used in Examples 1-5. | A cross-linked copolymer containing repeating units derived from a mixture comprising the following monomers: ##STR1## and occasionally other repeating units derived from other metathesis polymerizable cyclic compounds such as dicyclopentadiene, a process for producing the copolymer, a process for producing a molded article from the copolymer and a polymerizable composition therefor. | 2 |
BACKGROUND
[0001] Increasingly, data communications involve transmissions by optical sources that can deliver high volumes of digitized information as pulses of light. This is especially true for many communication companies that utilize laser diodes and optical fibers as their primary means for the transmission of voice, television and data signals for ground-based communications networks.
[0002] To achieve high bandwidth, laser diodes such as edge-emitting lasers and Vertical Cavity Surface Emitting Lasers (VCSELs) are commonly utilized as optical sources. These types of laser diodes are preferred due to their minute dimensions. For example, the typical VCSEL is measured in the order of micrometers. Consequently, an array of laser diodes can be integrated into a system to achieve high bandwidth transmissions.
[0003] In the manufacturing and production of VCSEL arrays, such as 1×12 or 1×4 parallel channel optical arrays, target optical and electrical characteristics are assigned to the arrays. To determine whether the VCSEL arrays will be operating at their target levels, each laser diode of the array is subjected to a burn-in process. That is, each VCSEL must be submitted to a quality control (QC) procedure that includes subjecting the VCSEL to a constant current at an elevated temperature for an extended time period. The burn-in current can be selected to be at a level that is higher than the standard operating current, since the QC procedure is a short-term test of whether the VCSELs will provide long-term performance during actual operating conditions. Similarly, the burn-in temperature is selected to be at a higher temperature than the anticipated operating temperature. Finally, the burn-in time period is selected on the basis of the type, specification and stringency of the devices.
[0004] Existing configurations use the laser driver to provide burn-in current to the laser diode. FIG. 1 is a block diagram of a conventional burn-in arrangement. Integrated circuit 10 includes an input buffer 12 , limiting amplifier 14 and laser driver 16 . An ASIC or other device provides signals to the integrated circuit 10 for applications such as communications. To perform the burn-in process, commands from an external digital controller 24 are submitted to an on-chip digital controller 22 . The on-chip digital controller 22 sends commands to laser driver 16 that generates the high burn-in current for laser diode 20 .
[0005] The use of an on-chip burn-in controller has several drawbacks. First, the on-chip digital controller 22 requires additional bonding pads on the integrated circuit 10 . These extra pads add parasitics that degrade performance (e.g., eye quality), particularly for high transmission rates such as 2.5 Gbps or higher. Furthermore, bonding between the integrated circuit 10 and the digital controller 22 requires a delicate and difficult procedure.
[0006] Another drawback to the configuration of FIG. 1 is that the laser driver 16 provides the burn-in current. This may require redundant calibration circuitry used to control the accuracy of the laser driver 16 during the burn-in phase. Furthermore, using laser driver 16 as the burn-in current source may cause degradation of laser driver 16 . The burn-in process is typically performed in a harsh environment (e.g., high temperature, high humidity), at a high DC current for a long time. This can result in degradation of laser driver 16 .
SUMMARY OF INVENTION
[0007] An embodiment of the invention is an integrated circuit for providing burn-in current to a laser diode. The integrated circuit includes a laser driver having an output for connection to the laser diode. Burn-in circuitry is formed on the integrated circuit and generates a burn-in current. A switch is formed on the integrated circuit and couples the burn-in current to the laser diode in response to an enable signal.
[0008] Another embodiment of the invention is a system for performing burn-in including a current source generating an input current and a laser diode. An integrated circuit includes a laser driver having an output for connection to the laser diode, burn-in circuitry formed on the integrated circuit generating a burn-in current and a switch formed on the integrated circuit for coupling the burn-in current to the laser diode in response to an enable signal.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a block diagram of a conventional system for laser diode burn-in.
[0010] FIG. 2 is a block diagram of a system for laser diode burn-in in an embodiment of the invention.
[0011] FIG. 3 is a schematic diagram of an on-chip burn-in circuit in an embodiment of the invention.
DETAILED DESCRIPTION
[0012] FIG. 2 is a block diagram of a system for laser diode burn-in in an embodiment of the invention. In FIG. 2 , integrated circuit 100 is an N-channel laser drive chip. Each channel includes an input buffer 102 , a limiting amplifier 104 , and a laser driver 106 . Input buffer 102 stores signals from a communication device prior to transmission to the laser driver 106 . Limiting amplifier 104 amplifies the output of input buffer 102 and provides the amplified signals to laser driver 106 . Laser diver 106 drives laser diode 110 to generate optical signals for communications. An ASIC 112 provides signals to each channel for communications. The laser diodes 110 may be part of a VCSEL in a communications device, such as a fiber optic transmitter.
[0013] Integrated circuit 100 includes a burn-in circuit 120 . As described in further detail herein, the burn-in circuit 120 generates burn-in current for the laser diodes 110 during the burn-in process. The burn-in circuit 120 is formed in the integrated circuit 100 and may be implemented in BiCMOS circuits. The burn-in circuit 120 includes N-outputs connected to each of the N laser diodes through switches 122 . A current source 124 provides a precise current to the burn-in circuit 120 . In exemplary embodiments, the burn-in circuit amplifies the input current and generates a burn-in current that is fed to the laser diodes 110 through switches 122 . An enable signal is provided to the burn-in circuit to activate the amplifier and close switches 122 . In alternate embodiments, the burn-in circuit serves as a signal buffer that buffers the input current without amplification.
[0014] FIG. 3 is schematic diagram of an on-chip burn-in circuit in an embodiment of the invention. Portions of integrated circuit 100 are not shown for ease of illustration. Shown in FIG. 3 is one section 130 of the burn-in circuit 120 generating burn-in current for one laser diode. Circuit section 130 includes an amplifier to amplify current from current source 124 and provide the amplified current to laser diode 110 . In the embodiment shown in FIG. 3 , the amplifier is a current mirror configuration implemented through field effect transistors 132 and 133 . Input current Ii from current source 124 is amplified to produce burn-in current 1 b . Alternatively, the burin-in circuit may buffer the input current without amplification.
[0015] An enable block 134 receives an enable signal from an external source. The external source may be a controller that generates an analog or digital enable signal that is applied to a pad on integrated circuit 100 or transmitted via an interface (e.g., a two wire serial interface). In response to the enable signal, the enable block 134 opens or closes switch 122 to provide the burn-in current to the laser diode 110 . In the embodiment shown in FIG. 3 , switch 122 is implemented using a field effect transistor. It is understood that other switch elements may be used to couple the burn-in current to laser diode 110 and that multiple transistors may be used to provide switch 122 (e.g., a multiple transistor pass gate).
[0016] Enable block 134 also sends signals to switches 142 and 144 . When switch 142 is closed, the gates of transistors 132 are connected to ground disabling these FETs. Similarly, when switch 144 is closed, the gates of transistors 133 are connected to Vcc disabling these FETs. Since the burn-in circuit 120 is operated during manufacturing, it is preferable to disable the current mirror amplifier once the burn-in process is complete. This prevents the burn-in circuit 120 from generating stray currents that may effect operation of the integrated circuit 100 .
[0017] In operation, when burn-in is to be performed, the enable signal is provided to enable block 134 . This causes switch 122 to close and switches 142 and 144 to open. Current from current source 124 is amplified by the burn-in circuit 120 and provided to the laser diodes 110 through switches 122 . When the burn-in process is complete, the enable signal changes states, closing switches 142 and 144 and opening switch 122 . This deactivates the burn-in circuit 120 and isolates the burn-in circuit from the laser diode 20 .
[0018] While exemplary embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation. | An integrated circuit for providing burn-in current to a laser diode. The integrated circuit includes a laser driver having an output for connection to the laser diode. Burn-in circuitry is formed on the integrated circuit and generates a burn-in current. A switch is formed on the integrated circuit and couples the burn-in current to the laser diode in response to an enable signal. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a device for performing measurements and/or taking samples in molten metals with a sublance, which has a sublance body, on whose one end a lance holder is arranged for receiving an immersion probe.
Such devices are sufficiently well known to those skilled in the art. They are used for measurements or taking samples in molten metals. Such sampling is partially automated, wherein a sublance is dipped into a melt container, after which the immersion probe arranged on the sublance is discarded, because it is used up, and a new immersion probe is placed on the sublance. In order to automate this procedure, the sublance must be able to be positioned exactly over a probe storage container.
In practice, however, it has been shown that, due to the loads exerted on a sublance during use, these sublances become slightly deformed, so that the lance holder can no longer be placed exactly over an immersion probe and the probe cannot be received without problems. The immersion probes placed on the sublances do not have the same exact length. In particular, the contact part housed in the carrier tube cannot always be reached at the same depth by the counter contact in the sublance. As a result, splashes of the molten metal frequently settle onto parts of the sublance, which must remain free for forming the contact, so that trouble-free placement of the immersion probes is impossible. This can disrupt the entire steel making process.
Sublances are known, for example, from European published patent application EP 69 433 A1. Here, an attempt is made to counteract the deformation of the sublance during the operation by rotating the sublance. The arrangement and function of sublances is further described in German published patent application DE 43 06 332 A1. Here, the exchanging procedure of the sample probes is also disclosed. Another sublance is known from European Patent EP 143 498 B1. The sublance described here has a seal, for example a rubber ring, at connection points, which prevents liquid metal from being able to penetrate into the mechanism.
The invention is based on the problem of improving the known sublances and especially enhancing the fail-safe means in automatic operation.
BRIEF SUMMARY OF THE INVENTION
The problem is solved for the invention characterized above in that on the lance holder a contact piece is arranged for making contact with signal lines of the immersion probe, furthermore in that the sublance body is movably connected to the lance holder or to a part thereof and/or in that the lance holder has several parts relatively movable to each other, whereby the contact piece is arranged to be movable relative to the sublance. The sublance is pushed tight onto the upper part of the lance holder and is preferably held so that it cannot move. The lower part of the lance holder is movable with the contact piece, so that the probe can be brought into contact with the contact piece. The lance holding can thereby adapt to the already set sensor, so that a sufficient contact is possible even for slightly deformed components or even when molten metal adheres to the sublance.
Different insertion depths of the sublance into the carrier tube of the immersion probe are likewise compensated in this manner. Preferably, the sublance body with the lance holder and/or the parts of the lance holder are arranged to be movable in the axial direction and/or in the radial direction. Furthermore, it is advantageous when the axial movement and the radial movement are realized by pairs of connection parts that are different from each other, in order to obtain the highest possible flexibility and adaptability. Especially for adhesion of molten metal on the sublance or for differently arranged contact parts of the immersion probe, an axial movement is important, in order to guarantee the correct contact with the immersion probe. In particular, it is advantageous when the movement is realized by elastic parts arranged between rigid parts, wherein the elastic parts can be formed as a spring, for example as a coil spring, or as an elastic ring.
Furthermore, it is useful if a part of the lance holder has a receiving hole, in which a peg of a second part of the lance holder can move in the axial direction, wherein a coil spring is arranged between the first and the second parts of the lance holder. For this purpose, it is advantageous if the coil spring is arranged between a stopping surface arranged at the front end or on the peripheral surface of the peg and a second stopping surface is arranged at or in the hole. The components guaranteeing the movement are thereby protected themselves.
It is useful if a part of the lance holder has a receiving hole, in which a peg of a second part of the lance holder is movable in the radial direction, wherein at least one elastic ring is arranged between the first and the second parts of the lance holder. The elastic ring can be arranged advantageously in the radial direction between the two parts of the lance holder.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
FIG. 1 is a schematic cross-sectional view of a converter furnace with a sublance;
FIG. 2 is a partially broken away schematic side longitudinal view of a sublance with lance holder and immersion probe according to one embodiment of the invention; and
FIG. 3 is a truncated schematic side longitudinal view of one embodiment of a lance holder in detail.
DETAILED DESCRIPTION OF THE INVENTION
In the converter furnace shown in FIG. 1 a blowing lance 1 is arranged, which blows oxygen into the molten slag 2 or molten steel 3 . Next to this lance a sublance 4 with an immersion probe 5 is arranged. The sublance 4 travels from above into the converter furnace until the immersion probe 5 is immersed in the molten steel 3 . After the measurement, the sublance is pulled up; the immersion probe 5 is destroyed.
If the probe is designed as a measurement probe, then the measurement is performed during the immersion in the molten steel 3 . A sample chamber arranged in the immersion probe 5 was filled while in the molten steel 3 . The sample chamber is removed from the discarded immersion probe 5 , and the sample can be analyzed. For the next measurement, another immersion probe 5 is taken from a storage container, usually mechanically mounted on the sublance 4 , and inserted into the converter furnace for the measurement.
FIG. 2 shows the immersion probe 5 arranged at the lower end of the sublance 4 . The immersion probe 5 has an immersion end, which is protected from the slag layer 2 lying on the molten steel 3 by a cap 6 , which exposes the sensor or the sample chamber only after being immersed in the molten steel 3 . The immersion probe 5 is fixed to the sublance 4 by means of the lance holder. The signal lines of the immersion probe 5 are contacted by a contact piece 7 arranged on the lance holder, so that the measurement signals can be led back through the sublance 4 to an analysis unit.
In FIG. 3 the lance holder is shown in detail. The lance holder is a reusable part of the sublance 4 . It is used for holding the immersion probe 5 and as a contact connection with the immersion probe 5 . The lance holder is connected to the water-cooled part of the sublance 4 . The water cooling is not explained in more detail in the Figures. It is sufficiently well known from the prior art (for example, EP 69 433).
The lance holder is arranged with its upper part 8 rigidly in the sublance 4 and with its lower part, beginning approximately at the separating line 9 , in the immersion probe 5 . In this way, the contact piece 7 guarantees the electrical contact with the signal lines of the immersion probe 5 . The conductance of the electrical signals and their transmission to a measurement or analysis station take place through the lance cable 10 , which is arranged at the upper end of the lance holder and which passes through the sublance 4 .
A rubber ring 11 is arranged in the upper region of the lance holder. The rubber ring 11 enables the lower part of the lance holder to move in both the radial direction and the axial direction relative to the upper part 8 . The rubber ring 11 is held against a stop 17 by a screw 16 . The screw 16 has a through hole 18 in the axial direction, which expands conically in the direction towards the contact piece 7 . The upper part 8 of the sublance 4 is thereby movable relative to the lower part in the radial direction and also slightly in the axial direction. Instead of a rubber ring 11 , a metal spring, for example a coil spring, can also be used.
The lower part of the lance holder with the contact piece 7 has a sealing sleeve 12 , into which a guide tube 13 projects. A coil spring 14 is arranged in the longitudinal direction between the guide tube 13 and an inner stopping surface of the sealing sleeve 12 . Movement of the contact piece 7 with the sealing sleeve 12 along the guide tube 13 is thereby guaranteed. This movement always ensures a secure contact between the signal lines of the immersion sensor 5 and the contact piece 7 , even with different lengths of the various immersion sensors 5 , which are mounted on the lance holder.
A secure contact is then guaranteed even if foreign matter, such as molten metal or slag, has become fixed on the lance holder. This can occur in the upper part of the lance holder, where the sublance 4 and the immersion probe 5 contact each other. Even in such a case of contamination, a reliable contact between the contact piece 7 and the signal lines of the immersion probe 5 is guaranteed by the spring 14 . The spring 14 preferably has a spring tension that is greater than the attachment force of the contact piece 7 on the so-called connector within the immersion probe 5 , with whose help the signal lines make contact with the contact piece.
Within the guide tube 13 coupling elements 15 can be provided, by which the lance cable 10 is connected to the contact piece 7 . In the manner shown, the contact piece 7 is arranged to be movable both in the longitudinal and the radial directions relative to the sublance 4 , and therefore can then be connected to the signal lines of the immersion probe, even if the lower end of the sublance 4 carrying the lance holder is slightly bent. A secure, mechanical holding of the immersion probe 5 is possible as well in practically every conceivable case.
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. | A device is provided for performing measurements and/or taking samples in molten metals with a sublance, which has a sublance body, on whose one end a lance holder is arranged for receiving an immersion probe. The sublance body is movably connected to the lance holder and/or the lance holder has several parts relatively movable to each other. | 5 |
This invention relates to a C-shaped fastening clip of the type having a pair of opposed walls that are biased toward one another by the head and tip of a threaded fastener respectively, and specifically to a novel configuration for the perimeter surface of the wall hole that is engaged by the fastener tip.
BACKGROUND OF THE INVENTION
Fastening clips of the type referred to above, which are sometimes called U-shaped or C-shaped, may be small, separable clips attached to a larger structure, or an integral part of a larger structure that is fastened to something else. I either case, each type has a pair of axially opposed walls joined by a generally perpendicular wall, hence the C- or U-shape. The threaded fastener has a head and tip, with threads, and often a predetermined length that can't be exceeded in the particular application. The fastener passes freely through a first wall, which is ultimately abutted, directly or indirectly, with the fastener head, and the tip passes through a hole in the opposed second wall, the edge of which is engaged by the side threads. This action tends to pinch or bias the walls toward one another as the fastener is tightened. The security or strength of the fastening achieved depends on how well and how securely the side threads of the fastener engage the hole in the second wall.
Prior art clips of the type referred to above often alter the perimeter area around the hole in the second wall to try to improve the fastener operation. Specifically, the perimeter is often formed into a dimpled or conical shape so as to funnel the fastener tip toward the hole edge. This also has the effect of moving the hole edge away from and out of the plane of the second wall, however. If there is a limitation on how long the fastener can be, then the edge of the hole may end up engaging fewer threads, the ones nearer the tip which may be smaller and less effective. Another common technique is to lance or split the thread engaging edge of the hole, which is displaced in opposite axial directions, creating separate edge portions to contact more threads of the fastener. This has two less than desirable effects. 20 The edge is weakened by being split in two, and an asymmetry is created at the split which causes the threaded fastener to pull in unevenly as it is tightened.
SUMMARY OF THE INVENTION
The invention provides a clip of the general type described above that has improved fastening strength and security, without the drawbacks of the prior art approaches. The perimeter surface of the hole that the fastener tip engages is configured with a generally conical rim that slopes down to a semi-circular edge. The semi-circular edges is thereby spaced away from and out of the plane of the second wall. The remainder of the perimeter surface, however, is configured as a pair of radially opposed strengthening corrugations. Each corrugation has a generally inverted U-shape, as does its edge, and the top or bight portion of that edge is still generally coplanar to the second wall.
The various elements of the perimeter surface so configured cooperate to achieve several advantages. The conical rim provides a lead in or funneling effect for the fastener tip, correcting for any initial misalignment. In addition, should the fastener tip hit either corrugation, it will still be funneled into the conical rim. Once the tip reaches the semi-circular edge, the more effective threads farther up the fastener can engage the two corrugation bight portions. This is achieved without lengthening the threaded fastener, since the bight portions are still basically in the plane of the second wall. Furthermore, the provision of the extra thread engaging edge is achieved without weakening the clip, since all the edge portions are continuous to one another, with no splits or discontinuities. Moreover, the strengthening corrugations actually reinforce the perimeter surface around the hole, as their name implies. In the embodiment disclosed, the provision of two, symmetrical corrugations, radially opposed, also causes the fastener to pull more evenly in on the second wall as it is tightened.
DESCRIPTION OF THE PREFERRED EMBODIMENT
These and other advantages and features of the invention will appear from the following written description and the drawings, in which:
FIG. 1 is a perspective view of a fastening clip according to the invention;
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a sectional taken along the line 3--3 of FIG. 1;
FIG. 4 is a view like FIG. 2 showing the possible positions in which the tip of a fastener can initially engage;
FIG. 5 is a view like FIG. 3 showing the final, tightened position of the fastener.
Referring first to FIGS. 1 and 5, a preferred embodiment of a fastening clip according to the invention is indicated generally at (10). Clip (10) has a first planar wall (12), a second planar wall (14) axially opposed, and is generally square in cross section. It should be kept in mind that while clip (10) is shown as a single, discrete part, it could in fact be part of a long channel in which several similar structures were embodied. Clip (10) is designed to interact with a conventional threaded fastener, indicated generally at (16). Fastener (16) has a head, not illustrated, and a sharper, smaller tip (18) from which a thread form begins, creating smaller diameter tip threads (20) and larger side threads (22) located axially farther up from the tip (18). Of course, a single thread form creates both. In many applications, there is a limit to how long fastener (16) can be. Stated differently, there is a practical limit to how far tip (18) is allowed to extend through the second, lower wall (14), because of clearance limitations. The invention works within that limitation.
Referring next to FIGS. 1, upper wall (12) has a simple round hole (24) large enough to pass fastener (16) freely, but small enough that the head of fastener (16) will abut it when tightened, either directly or indirectly. Directly axially opposed to upper hole (24) is a hole (26) that has a perimeter surface comprised of two basic features, a concave (as viewed from above lower wall (14) conical rim (28) and two diametrically opposed, convex reinforcing corrugations (30). The corrugations (30) divide the rim (28), without interrupting or cutting it, in two. The perimeter surface of hole (26) is, in general, formed by a two-part die or tool, not illustrated, each half of which is pressed together from above and below into lower wall (14) after lower hole (26) is drilled. While the material of lower wall (14) is thinned out somewhat in this forming process, it is again important to note that is not lanced or cut at any point.
Referring next to FIGS. 2 and 3, more detail is illustrated. The conical rim (28) slopes down to a semi-circular edge (32), which lies on a circle that is parallel to and axially spaced from the underside of lower wall (14). Each strengthening corrugation (30) has a sharp, inverted U-shape, with steeply sloped sides that slope down to and blend continuously into the rim (28). The U-shaped corrugations (30) provide a pair of similarly shaped edges which, in general, blend into the semi-circular edge (32) to create one, rippled or scalloped edge. A pair of edge bight portions (34) are created that lie close to, almost in, the plane of lower wall (14). The perimeter surface formed is, overall, symmetrical and smooth, and, most importantly, continuous and uninterrupted. The rippled corrugated effect created serves to strengthen and stiffen the whole perimeter surface, as opposed to a broken or split surface.
Referring next to FIGS. 4 and 5, the operation of the invention is illustrated. After passing through upper hole (24), the fastener tip (18) may directly enter lower hole (26). It is more likely, however, that it will cock into any one of several positions off axis, as shown by the dotted lines in FIG. 4, and hit either the top of a corrugation (30), or the conical rim (28). If the former, then the tip (18) will slide down to the rim (28), and eventually into lower hole (26). So the funneling, lead in effect of rim (28) is not interfered with, and in fact is assisted by, the steep sides of the corrugations (30). There are no cracks or splits in which the tip (18) could potentially catch or be hung up. Once the tip (18) is led into lower hole (26) and is turned and tightened, the tip threads (20) can engage the semi-circular edge (32). Again, being smaller in diameter, the tip threads (20) do not potentially engage or bite as tightly as the larger diameter side threads (22). These, however, are now able to engage the bight portions (34), which are close to the plane of lower wall (14), as best illustrated in FIG. 5. This extra thread engaging capability can provide a significantly stronger and more secure connection, with a fastener (16) that is relatively short. Furthermore, in the embodiment disclosed, the provision of two edge bight portions (34) diametrically opposed to one another allows the fastener (16) to pull up or in on lower wall (14) more evenly, biasing the walls (12) and (14) together. In conclusion, a high degree of cooperation among the features of the perimeter surface described leads to a stronger and stiffer surface, improved lead in of the fastener, and improved thread engagement and fastener security.
Variations in the embodiment disclosed could be made. For example, more or fewer corrugations (30) could be provided, such as one or three. It is advantageous that they be evenly and symmetrically spaced, however. Therefore, it will be understood that it is not intended to limit the scope of the invention to just the embodiment disclosed. | An improved fastening clip of the U- or C-shaped type has a thread engaging hole in the axially opposed clip wall with a novel hole form. The perimeter surface of the hole includes a cooperating conical rim and pair of strengthening corrugations that work together to lead the fastener tip into the hole, as well as to strengthen and stiffen the surface. The corrugations also provide thread engaging bight portions close to the plane of the axially opposed clip wall, providing added fastening security with a relatively short fastener. | 5 |
This application is a continuation-in-part of application Ser. No. 08/109,121, filed 19 Aug. 1993, now U.S. Pat. No. 5,395,354.
BACKGROUND
FIELD OF THE INVENTION
The invention relates to surgical drapes for maintenance of a surgical field and for collection of waste fluid.
Waste Fluid in Surgery
Irrigation fluid is commonly used in open surgery as well as in endoscopic examination and surgery performed on the vagina and uterus (transvaginally) and on the urethra and bladder (transurethrally). Any such anatomic approach requires sufficient dilation or spreading of the tissues to allow manipulation of the surgical instruments and to give the surgeon visibility to properly perform the surgery. In an anesthetized patient, clamps and/or retractors are used to maintain open surgical access and a weighted speculum is commonly employed to maintain the desired degree of vaginal dilation. A urethra is typically progressively dilated just prior to insertion of an endoscope guide tube.
Waste irrigation fluid drains at least intermittently from open surgical sites, as well as through and around the endoscope during transvaginal and transurethral endoscopic surgery. An intermittent or continuous flow of water-based (generally nonconducting) irrigation fluid from an external reservoir is directed to the surgical site by tubing, syringes, small containers or through the endoscope. Waste irrigation fluid drains, in turn, from the open surgical access, the vagina or the urethra.
Irrigation fluid flow in the area of surgery removes small pieces of excised tissue and blood, continually clearing the surgeon's view of the operative site(s). Most of the irrigation fluid which flows to the operative site is subsequently flushed out by additional irrigation fluid, but a portion of the entering fluid may be absorbed through the tissue surfaces of the operative site and through parts of the patient's vascular system exposed by the surgery.
During relatively prolonged and/or invasive surgery, sufficient fluid may be absorbed to substantially adversely alter the patient's serum electrolyte balance. Because serious electrolyte imbalances may result in seizures, coma or death of the patient, the surgeon must have sufficient warning of impending fluid overload to take corrective action. While this can be accomplished through frequent estimates of serum electrolyte levels during the surgical procedures, an easier and less expensive method involves estimation of the amount of fluid absorbed. In turn, this requires accurate estimates of the difference in the amounts of irrigation fluid administered and waste irrigation fluid lost. If blood loss can be accurately estimated or is clinically insignificant, the irrigation fluid difference can serve as an estimate of absorbed irrigation fluid. Errors in estimating the difference most often arise in estimating the amount of irrigation fluid lost because such fluid is typically hard to recover completely.
A fraction of the drained waste irrigation fluid typically falls on surgical drapes and thence to the operating table or floor, where it is commonly lost without being measured. Because the volume of this lost fraction of waste fluid is generally unknown, the amount of irrigation fluid absorbed by the patient is difficult to estimate accurately during the course of an operation.
SUMMARY OF THE INVENTION
The present invention relates to apparatus for collecting and measuring waste irrigation fluid drained from a surgical site, including that draining from an endoscope, urethra or vagina and otherwise released in connection with the use of endoscopic instruments for surgery. Accurate measurement of waste irrigation fluid volume facilitates estimation of the amount of irrigation fluid absorbed by a patient, and the present invention comprises surgical drapes and related apparatus to facilitate collection and measurement of waste irrigation fluid.
A preferred embodiment of a disposable surgical drape of the present invention comprises a splash shield, folding funnel and folding frame means. These components are made to be coupled adhesively in certain preferred embodiments so that the pieces may be interchanged and/or purchased separately. The splash shield and folding funnel are preferably fabricated substantially of sheet plastic and/or non-woven sheet material which has been treated for water resistance.
The splash shield may be substantially flat or it may have edges gathered substantially in the manner of a fitted sheet. It is intended for substantially horizontal placement under a patient to direct waste irrigation fluid flow to the folding funnel. Typically, the splash shield will be placed under a patient in the lithotomy position and extend substantially to or over the end of the operating table facing the surgeon. The splash shield is preferably wide enough to catch substantially all waste irrigation fluid draining from the patient which does not fall directly into the funnel portion.
Waste fluid falling on the splash shield when it is substantially horizontal will tend to flow toward the center line of the operating table due to the weight of the patient which compresses the table pads together with the splash shield portion which lies between the patient and the table pads. Waste fluid on the splash shield will further tend to flow toward the end of the operating table facing the surgeon or toward the other end of the table, depending on how the table is tilted. That which flows toward the surgeon tends to flow over at least a portion of the folding frame means and into the funnel. For this reason, a drip shield which loosely falls over the upper portion of the folding frame base may optionally be sealingly coupled to the splash shield to facilitate fluid flow over the folding frame means. The drip shield is preferably coupled to the splash shield by heat sealing or an analogous process which produces a highly water-resistant bond. When so used, the drip shield will tend to shield from water damage or leakage the (preferably adhesive) coupling of the folding frame means to the folding funnel, as well as the (preferably adhesive) coupling of the folding funnel mouth to the splash shield.
A folding funnel receives fluid flow from the splash shield, the folding funnel comprising a funnel body having a funnel mouth and a funnel mouth edge. At least a portion of the funnel mouth edge is sealingly coupled to the splash shield (as, for example, by heat sealing of sheet plastic or, preferably, by use of water-resistant adhesives). The folding funnel is so constructed as to have a substantially frusto-conical or frusto-pyramidal shape when suspended freely under the influence of gravity with the plane of the funnel mouth uppermost and substantially horizontal. A sufficient length of funnel mouth edge is sealingly coupled to the splash shield to ensure that substantially all fluid flow over the end of the operating table facing the surgeon will enter the folding funnel, assuming the funnel mouth is being held substantially open by the folding frame means.
Folding frame means are coupled to the folding funnel for the purpose of holding open the funnel mouth. Folding frame means comprise a substantially planar (preferably plastic) base which is relatively rigid compared to the sheet material of the splash shield and folding funnel. The base has a first end, a second end, a substantially centered longitudinal axis extending between the first and second ends, and a longitudinal bending compliance along the longitudinal axis. Additionally, folding frame means comprise at least one resilient elongated strut, each strut having a proximal end and a distal end and a longitudinal bending compliance greater than the base longitudinal bending compliance, each strut proximal end being coupled to the base. Each strut distal end comprises edge coupling means for coupling the strut to a funnel mouth edge, and hinge means are used for coupling each strut to the base. Hinge means may include, for example, a thinned section of relatively thicker plastic material (a living hinge) or a hinge of conventional design (analogous to a piano hinge). To maintain the folding funnel in a preferred orientation during use, strut hinge means may preferably be designed to transmit torque in a substantially vertical plane.
Edge coupling means may comprise, for example, a protrusion of reduced cross-sectional area (relative to the strut) which projects from the distal end of the strut to engage a hole in the funnel mouth edge. Alternatively, edge coupling means may comprise an adhesive area on the distal strut end to bond with a portion of the funnel mouth edge. Still another alternative edge coupling means may comprise a hook-and-loop area on the distal strut end (covered, for example, with Velcro) to adjustably attach to a corresponding portion of the funnel mouth edge having a mating hook-and-loop area.
Struts are intended to fold compactly against the base for shipment and storage and to hold the funnel mouth open during use of the disposable surgical drape, preferably so that the funnel mouth edge is in tension sufficient to keep it from sagging noticeably. Ideally, struts would be substantially straight while maintaining the desired edge tension, but to allow for manufacturing tolerances in the funnel edge length, struts will preferably experience more or less longitudinal bending under a compressive load caused by the edge tension. Such longitudinal bending will result in a shortened straight-line distance between proximal and distal ends of a strut (effectively, "strut shortening ") relative to the strut length when straight. The degree of bending compliance is then conveniently measured in units of strut shortening per unit of compressive load. Slightly undersized funnel mouths will resulting in relatively greater compressive loads and thus more strut shortening, while slightly oversized mouths will result in relatively smaller compressive loads and thus less strut shortening.
Preferred embodiments of the folding frame means comprise from one to three struts including, for example, first and second resilient elongated struts having lengths and longitudinal bending compliances that are substantially equal. A third resilient elongated strut may be added having a longitudinal bending compliance greater than the first strut longitudinal bending compliance and length greater than the first strut length to attain certain desired funnel mouth shapes.
Note that certain preferred embodiments of the invention may also (or alternatively) incorporate a predetermined compliance in tension (units of elongation per unit of tension load) in the funnel mouth edge. Further, the funnel mouth edge may be designed to have a non-uniform compliance in tension when it is desirable to maintain certain portions of the funnel mouth opening as having a highly repeatable appearance, notwithstanding the effects manufacturing tolerances on strut length and funnel mouth edge length. Non-uniform compliance in tension is preferably achieved, for example, by coupling (as by heat sealing) elongated resilient tension members such as plastic or rubber strips to one or more predetermined portions of the funnel mouth edge.
Folding frame means may optionally additionally comprise a longitudinally hinged portion of the base to which all elongated struts are coupled for adjusting elevation of each strut. The (preferably living) hinge is preferably located along at least a portion of the superior edge of the hinged portion. When, for example, struts extend substantially perpendicularly from a longitudinally hinged portion of a base, adjustment of strut elevation can bring each strut into a substantially horizontal position. Since in use, struts will normally lie substantially in the plane of the funnel mouth, the funnel mouth can be made substantially horizontal (its preferred orientation in use). To keep the funnel mouth substantially horizontal, an elongated hinge lock (preferably in the form of a rod or bar) maintains the adjustment of the longitudinally hinged portion when it is present by either preventing it from closing (that is, moving toward a substantially coplanar position with the remainder of the base), or preventing it from opening. In the former case, the elongated hinge lock is adjustably coupled to the base in such a position as to keep the hinged portion of the base from being completely closed. Such hinge lock coupling to the base can conveniently be achieved through hook-and-loop areas of the hinge lock ends and corresponding portions of the base in contact with the hinge lock ends.
In use with the funnel mouth substantially horizontal as described above, the funnel weight acts through the strut(s) to create a bending moment tending to rotate the base around an axis substantially parallel to its longitudinal axis (thus distorting the splash shield to which the base is coupled). To resist such a bending moment, the folding frame means base may comprise at least one stiffener to aid in maintaining a desired elevation of each resilient strut. Stiffeners are (preferably substantially coplanar) projections from the base that may be coupled to the splash shield in the same manner as the base or may simply rest against it if the applied bending moment will tend to move the stiffener toward the splash shield. By increasing the degree of rotational coupling of the base to the splash shield, the latter structure may exert greater compensating torque on the base which will tend to hold the funnel mouth substantially horizontal.
Another structure which may be used (alone or in conjunction with the above stiffeners) to counteract the above base bending moment in surgical drapes of the present invention comprises at least one elongated suspension strap adjustably coupling the splash shield and the folding frame means for holding the open funnel mouth substantially horizontal. Adjustability of the coupling may be attained through use of, for example, hook-and-loop fasteners (such as Velcro) or adhesive pads on one or both suspension strap ends and/or the splash shield. Suspension straps, of course, are preferably adjustably coupled to struts and may conveniently be adhered to or looped around them, the latter providing a sliding adjustment. When this loop-adjustment embodiment is preferred, struts and/or the suspension straps, which adjustably slide over and support them may incorporate relatively high-friction surfaces to provide a relatively stable (but easily changed) adjustment after the strap is placed in tension due to the load imposed by holding the funnel mouth substantially horizontal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a preferred embodiment of the folding frame means comprising optional stiffeners.
FIGS. 2A-C schematically illustrate plan views of various representative funnel mouth configurations achievable in disposable surgical drapes of the present invention.
FIG. 3 schematically illustrates a disposable surgical drape prepared for use and incorporating optional suspension straps.
DETAILED DESCRIPTION
Disposable surgical drapes of the present invention comprise a splash shield 49, folding funnel 60 and folding frame means 10. The splash shield 49 is for substantially horizontal placement in use as shown in FIG. 3, and the folding funnel 60 is for substantially vertical placement in use (also shown in FIG. 3). While optionally being sold and/or shipped separately, the folding funnel 60 in use is sealingly (preferably adhesively) coupled to the splash shield 49, with the folding frame means 10 sealingly (preferably adhesively) coupled to the folding funnel 60. Note that the folding frame means may optionally be placed so as to be directly in contact with (and coupled to) the folding funnel 60 only or both the folding funnel 60 and the splash shield 49.
The folding funnel 60 comprises a funnel body 50 having a funnel mouth 55,55',55" which is a substantially planar area enclosed by a funnel mouth edge 53. Note that through various arrangements of struts 28,28' in relation to the base 20 of folding frame means 10, funnel mouth 55,55',55" can be given various shapes (three examples of such shapes being schematically illustrated in FIGS. 2A-C). The above surgical drape may optionally additionally comprise a drip shield 61 sealingly coupled to splash shield 49 to facilitate fluid flow over the base 20 of folding frame means 10. Other optional components of the above surgical drape are funnel drain connector 51 (which couples funnel body 50 with funnel drain hose 52) and elongated suspension straps 70 (FIG. 3) for adjustably coupling splash shield 49 and folding frame means 10 for holding funnel mouth 55,55'55" substantially horizontal in use. Note that suspension straps 70 are preferably coupled to splash shield 49 through coupling areas 71 (which may comprise, for example, adhesive portions or hook-and-eye portions for coupling with corresponding portions on splash shield 49). At the ends of suspension straps 70 opposite coupling areas 71, the straps will preferably be coupled to struts 28,28' as desired in an analogous manner or by looping straps 70 around struts 28,28' and coupling the strap ends to the straps 70 themselves in the manner described above.
Folding frame means 10 as schematically illustrated in FIG. 1 comprises a base 20 and two resilient elongated struts 28. Each strut 28 distal end comprises edge coupling means 31 for coupling the strut 28 to a funnel mouth edge 53. Hinge means 14,14' comprise a proximal portion 24,24' which is coupled (as by plastic welding or gluing) to base 20 and includes joint 16,16'. Joint 16,16' may comprise, for example, a thinned section of relatively thicker plastic material (a living hinge joint) or a hinge joint of conventional design (analogous to a piano hinge joint). Note that the living hinge joints 16 schematically illustrated in FIG. 1 are designed to transmit torque in a substantially vertical plane (that is, in use they resist the tendency of any weight applied to struts 28 (such as a folding funnel 60) to pull the struts 28 below a horizontal plane.
Another feature of the present invention which can be used to keep struts 28,28' in a substantially horizontal plane is the longitudinally hinged portion 21 of base 20. FIG. 1 schematically illustrates the superiorly located hinge 22 as well as elongated hinge lock 25 for maintaining adjustment of longitudinally hinged portion 21. Elongated hinge lock 25 is shown as being adjustably coupled (through areas adjacent its ends) to corresponding coupling areas 26 of base 20. Other features of the present invention which can be used to keep struts 28,28' in a substantially horizontal plane are the stiffeners 30 (also shown in FIG. 1). Note that when a third resilient elongated strut 28' is placed between two relatively shorter struts 28 as schematically illustrated in FIG. 2C, the funnel mouth 55" which is created is relatively deeper than the corresponding funnel mouth 55 which is created by two struts 28 (schematically illustrated in FIG. 2A). The deeper funnel mouth 55" will tend to exert a greater bending moment on base 20 than funnel mouth 55. To resist a greater bending moment, each strut may preferably have an "I" beam or "H" beam cross-section to resist bending along its longitudinal axis in a substantially vertical plane under the weight of the funnel (i.e., relatively low vertical bending compliance), while at the same time having a substantially greater longitudinal bending compliance in a substantially horizontal plane (i.e., relatively high horizontal bending compliance).
Edge coupling means 31 (shown in FIG. 1) are intended to reversibly prevent lateral movement of the distal end of a strut 28,28' with respect to a portion of the funnel mouth edge 53. Edge coupling means 31 may comprise a small protrusion at the distal end of a strut 28 (as schematically illustrated), the protrusion being sized to allow its insertion into a properly located and closely fitting hole in the funnel mouth edge 53. Edge coupling means may also comprise a socket portion molded into or otherwise coupled to the funnel mouth edge, the socket portion reversibly coupling (preferably with a snap or friction fit) a ball portion located at a strut 28,28' distal end. Still another embodiment of edge coupling means 31 may comprise a separate socket portion which can be reversibly applied to a ball portion on a strut 28 distal end with a portion of the funnel mouth edge 53 reversibly trapped between the ball portion and the socket portion. The latter edge coupling means 31 embodiment is intended to be adjustably applicable to any of a plurality of locations on the funnel mouth edge 53. Note that the ball and socket need not be spherical or smooth, but may be substantially ellipsoidal or substantially cylindrical or may comprise one or more solid angles to enhance its anchoring function and/or its reversible coupling function.
In general, a strut 28,28' substantially crosses from one portion of the funnel mouth 55,55',55" to another portion. The funnel mouth 55,55',55" is preferably maintained open in some desired shape and in tension by the combined resilience of the base 20 and one or more struts 28,28'. While longitudinal (that is, bending) compliance of both the base 20 and struts 28,28' contributes to shaping of the funnel mouth, strut longitudinal compliance exceeds base longitudinal compliance in preferred embodiments. Note also that certain portions of the funnel mouth edge 53 may preferably have greater compliance in tension than adjacent portions, the non-uniform compliance in tension being useful in compensating for manufacturing tolerances in various portions of the disposable surgical drape while assuring a substantially repeatable and predetermined funnel mouth shape.
The present invention is particularly adapted for use with a malleable speculum during transvaginal endoscopic surgery. A malleable speculum may be used independently or may be sealingly coupled either reversibly or substantially irreversibly to an apron-funnel-splash shield assembly to facilitate collection of waste fluid drainage (see U.S. Pat. No. 5,395,354, Mar. 7, 1995, Vancaillie, a divisional of application Ser. No. 08/109,121, filed 19 Aug. 1993, incorporated herein by reference). The malleable speculum may be used without the apron-funnel-splash shield assembly for operations wherein accurate estimation of the amounts of drained and absorbed irrigation fluid is regarded as unnecessary because the absorption of clinically significant amounts is unlikely. However, because the duration and/or invasive character of a surgical procedure may be difficult to precisely predict, a requirement for collection and accurate measurement of drainage fluid is often presumed. Thus, the malleable speculum may be present in a preferred embodiment of the present invention as part of a drape assembly comprising a speculum, an apron, a folding funnel, a splash shield, and folding frame means. This assembly acts to provide the desired degree of vaginal dilation and to improve the accuracy of fluid absorption estimates during endoscopic surgery. The latter function includes collecting and measuring both the irrigation fluid which fails directly on components of the drape assembly and that which reaches the drape assembly after flowing over the patient or portions of the surgical and operating room support apparatus associated with the operation. | A disposable surgical drape having a folding funnel, folding frame means, and splash shield functions as a fluid collector for use during surgery. A portion of the splash shield is placed under the patient while the remainder extends over the operating table end to direct fluid flow to a folding funnel which is shaped and positioned as desired with folding frame means. Fluid draining into the funnel is collected for measurement. Folding frame means impart a substantially frusto-conical or frusto-pyramidal shape to the funnel in use and employ one or more hinged struts to help maintain the funnel mouth substantially open and horizontal. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of Provisional Application No. 60/630,985, filed Nov. 24, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to recreational vehicles.
BACKGROUND OF THE INVENTION
[0003] Recreational vehicles that are intended to be moved between locations at which they function as temporary housing benefit from having living areas that can be increased when the vehicles are not being transported. One way to provide an expandable living area is to use a slide-out. A slide-out typically has three walls, a floor, and a ceiling, and fits within a larger central living area when a vehicle is being transported, and is slid out to extend outward from a side of the vehicle when it is not being transported. Examples of vehicles with slide-outs can be found in at least U.S. Pat. Nos. 6,623,058, 6,293,612, 6,290,284, 6,286,883, 6,170,903, 6,135,525, 6,098,346, 5,248,180, 4,480,866, 3,719,386, 2,965,412, 2,704,203, 2,225,319, and 2,177,394, herein incorporated by reference in their entireties.
[0004] Over time, recreational vehicle size has increased. Vehicle size increases, particularly increases in length, have made it desirable to increase slide-out lengths as a full wall slide-out (i.e. a slide-out extending along more than half of the length of the side of the vehicle it slides out from) provides a larger increase in living area than a shorter slide-out. Unfortunately, increased slide-out length presents difficulties in vehicle design that have yet to be overcome. As such, there is a need for improved vehicle structures and construction methods that facilitate the use of extended length slide-outs.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a mobile recreational vehicle including a body enclosing a living area designed to serve as self-contained living quarters during recreational travel, where the body is supported on at least one pair of wheels (and often two or more pairs). The vehicle includes a ceiling assembly, a floor assembly; and an elongated and adjustable ceiling support extending between the ceiling assembly and the floor assembly wherein the height of the support can be adjusted during installation. The present invention is also directed to mobile recreational vehicles having shortened full length slide-outs to allow for additional side ceiling support, and for mobile recreational vehicles that have slide-out openings that have cambered upper edges to minimize sagging of such openings with minimal vertical supports.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The exact nature of this invention, as well as the objects and advantages thereof, will become readily apparent from consideration of the following specification in conjunction with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:
[0007] FIG. 1 is a perspective view of a recreational vehicle;
[0008] FIG. 2 is a perspective view of the vehicle of FIG. 1 with an extended slide-out;
[0009] FIG. 3 is a left perspective view of the a support frame of the vehicle of FIG. 1 ;
[0010] FIG. 4 is a right perspective view of the support frame and slide-out of the vehicle of FIG. 1 .
[0011] FIG. 5 is a perspective view of an adjustable center ceiling support of the support frame of FIG. 3 ;
[0012] FIG. 6 is a side view of the support of FIG. 5 ;
[0013] FIG. 6A is a cutaway view of the top portion of FIG. 5 ;
[0014] FIG. 7 is a partial side view of a portion of the sidewall support framing of the frame of FIG. 3 that includes a sidewall ceiling support;
[0015] FIG. 8 is an exaggerated illustration of the cambering of a portion of the support frame of the vehicle of FIG. 3 ;
[0016] FIG. 9 is a cutaway view of the vehicle of FIG. 1 with the slide-out retracted;
[0017] FIG. 10 is a partial perspective view of the vehicle of FIG. 1 with the slide-out retracted;
[0018] FIG. 11 is a cutaway view of the vehicle of FIG. 1 with the slide-out extended;
[0019] FIG. 12 is a partial perspective view of the vehicle of FIG. 1 with the slide-out extended;
[0020] FIG. 13 is a perspective view of an alternative recreational vehicle;
[0021] FIG. 14 is a perspective view of the vehicle of FIG. 13 with an extended slide-out
[0022] FIG. 15 is a perspective view of another alternative recreational vehicle; and
[0023] FIG. 16 is a perspective view of the vehicle of FIG. 15 with an extended slide-out
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Reference will now be made to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that these embodiments are not intended to limit the invention. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure the important aspects of the present invention. Moreover, the embodiments of the present invention described herein comprise multiple novel features with each described embodiment including either a single such feature or a combination of such features. Other contemplated embodiments include all combinations of one or more such novel features not explicitly described herein as such combinations are readily discernable from the embodiments described.
[0025] Although recreational vehicles slide-outs have been in use for several decades, recent increases in vehicle size and in expectations regarding vehicle weight, durability, and features necessitate improvements in vehicle structure that have not previously been provided. As an example, as slide-out length increases, the length of slide-out openings increases with a corresponding decrease in the amount of ceiling structure support provided by the sidewalls. The decrease in support occurs in regard to both vertical movement of the ceiling structure as well as in regard to lateral movement, twisting, and vibration of the ceiling structure. Decreased support is an issue both when the vehicle is in motion with any slide-outs retracted, and when the vehicle is at rest with slide-outs extended.
[0026] Compensating for the decreased support is complicated by the fact that it is undesirable to fill the expanded living area of the recreational vehicle with supports. Further complications arise from the fact that it is desirable to keep the total vehicle weight to a minimum, and to minimize the cost, at least in regard to time, labor, and materials, of manufacturing the vehicle.
[0027] As will be discussed herein, a balance between conflicting design criteria is achieved through the use of one or more of the following: a shallower slide-out coupled with an adjustable center ceiling support, a shortened sidewall coupled with a sidewall ceiling support, and a cambered horizontal support positioned above the slide-out opening. The term “shortened” in this instance indicates that, although it is desirable to maximize the length of the slide-out, it is beneficial in some instances to sacrifice some of the length to a sidewall ceiling support. As such, a “full wall” slide-out as described herein is any slide-out that extends along at least 50% of the length of the vehicle, and preferably extends at least 70% of the length of the vehicle.
[0028] Referring primarily to FIGS. 1 and 2 , a recreational vehicle 1 that is a motor-home comprises a hull 3 , a full wall slide-out 5 , and a slide-out opening 7 , as well as a top/ceiling/roof 9 , a bottom/floor 11 , a front 13 , a rear 15 , a right side 17 , and a left side 19 . In FIG. 1 , the slide-out 5 is in a retracted position, and in FIG. 2 is in an extended position. Extending the slide-out 5 increases the size of an expandable living area cavity 21 (see FIGS. 3 and 11 ) enclosed by the ceiling 9 , the floor 11 , the front 13 , the rear 15 , the sides 17 and 19 , and slide-out 5 . In addition to the features shown, the vehicle 1 will typically comprise a gas or diesel engine, a transmission, a cab including controls used while driving the vehicle 1 , and also including a driver's seat and a passenger seat positioned to facilitate control of the vehicle while looking out the front of the vehicle.
[0029] Although most of the figures depict a motor-home, the methods and apparatus disclosed herein are equally applicable to other recreational vehicles, and particularly to recreational vehicles comprising a mobile chassis. As such, the term recreational vehicle includes at least motor-homes and travel trailers. As an example, in FIGS. 13 and 14 a recreational vehicle 201 that is a standard travel trailer is shown with its slide-out 205 retracted and extended. In FIGS. 15 and 16 , a recreational vehicle 301 that is a fifth wheel travel trailer is shown with its slide-out 305 retracted and extended.
[0030] Although the figures depict a single slide-out embodiment, the features described are also applicable to vehicles comprising multiple slide-outs such as vehicles having both left and right slide-outs.
[0031] Referring to FIGS. 3 and 4 , the hull 3 of the vehicle 1 comprises an internal support frame 23 . The roof/ceiling portion of the frame 23 includes longitudinal supports (“ceiling extrusions”) 25 and transverse supports (“ceiling ribs”) 27 . The ceiling extrusions 25 and the ceiling ribs are preferably pre-assembled into a layered ceiling assembly having an external roof/skin layer separated from an internal ceiling layer by an insulating layer that includes the ceiling ribs and ceiling extrusions. After a substantial portion of the floor and sidewalls of the frame 23 are assembled, the ceiling assembly can be put in place as a single piece. The frame 23 also includes vertical supports 29 , an adjustable center ceiling support 31 , a sidewall ceiling support 33 , cambered tubular members 57 and 63 , an adjustable center ceiling support receiving transverse support (“transverse cantilever”) 59 , lower longitudinal supports 26 , lower transverse supports 28 , a lower transverse support 64 , and a ceiling support arch 61 . The supports 31 and 33 help support the layered ceiling assembly of ceiling 9 . The support 33 , members 57 and 63 , and vertical support 29 are preferably incorporated into a pre-assembled sidewall in a manner similar to the roof/ceiling portion of the frame 23 .
[0032] The arch support 61 is coupled to a top surface of the transverse cantilever 59 and comprises one or more openings extending through it to facilitate routing of wires and the like. The arch support 61 maintains a minimum distance between the transverse cantilever 59 and any points on the roof/ceiling assembly immediately above the arch support 61 .
[0033] In addition, to the elements shown, a recreational vehicle hull will typically comprise one or more of the following: external and internal panels including or covering support frame 23 , windows permitting light and/or air to pass through the sides of the hull 3 , vents permitting air to pass through the sides, floor, and/or ceiling of the hull 3 , exterior access doors permitting entry into the living area cavity 21 , dividers for dividing the living area cavity 21 into smaller areas, cabinets for storage, interior doors permitting movement between rooms, and electrical and plumbing components.
[0034] Referring to FIGS. 5, 6 , and 6 A, the adjustable center ceiling support 31 comprises horizontal members 35 , vertical members 37 , cross-braces 39 , alignment plates 41 , support plates 42 , and adjustment assemblies 43 . The adjustment assemblies 43 each comprise an adjustment bolt 45 , nuts 47 , and washers 49 . The members 35 and 37 and braces 39 may be hollow or solid, comprise a single pieces or an assembly of pieces, and/or comprise a single material or a plurality of materials. Moreover, the members 35 and 37 may be coupled together in any manner. However, in some instances it may be advantageous if the support 31 comprised steel or aluminum tubing welded together such that the members 35 and 37 form a rectangular frame with the cross-braces 39 extending between points at or near the internal corners of the frame. In the embodiment shown, the cross-braces 39 are coupled to the horizontal members 35 at points near but not in the corners of the rectangle formed by the members 35 and 37 . Positioning the ends of the members 39 away from the members 37 allows the adjustment assemblies 43 to be positioned closer to the members 37 . The plates 41 and 42 add rigidity to the support 31 . Having the plates 41 extend beyond the edge formed by the upper horizontal member 35 allows the plates 41 to be used to align the support 31 under the transverse cantilever 59 . There will typically be a gap 67 between an upper horizontal member 35 and transverse cantilever 59 . The size of the gap 67 as well as the distance between supports 59 and 64 can be adjusted using the adjustment assemblies 43 .
[0035] Although the size and dimensions of the support 31 may vary between embodiments, it is preferred that it fit between the ceiling and the floor of the living area, i.e. between the ceiling ribs 27 and the lower transverse supports 28 . As shown, the support 31 fits between the transverse cantilever 59 and a lower transverse support 64 . It is contemplated that in some instances the support 31 will have a width between 24 and 48 inches, a height without including adjustment assemblies between 79 and 96 inches, and adjustment assemblies that can maintain a maximum sidewall opening size of between 76 and 93 inches, and will be able to support static loads of at least 400 pounds.
[0036] Although a single support 31 is shown, in some instances an embodiment may comprise two or more supports 31 . Although shown positioned in the center of vehicle 1 and perpendicular to the side comprising the slide-out, in some instances the support 31 may be positioned other than in the center of the vehicle and/or other than perpendicular to the slide-out side(s). Although shown comprising bolts, nuts, and washers, the adjustment assemblies 43 may comprise any mechanism that supports the ceiling 9 of the hull 3 but allows the distance between the ceiling ribs 27 and the lower transverse supports 28 adjacent to support the 31 to be adjusted. An alternative mechanism might include a pivot opposite of the slide-out 5 and a single adjustment assembly.
[0037] The adjustment assemblies 43 can be operated to increase or decrease the gap 67 between an upper horizontal member 35 and the transverse cantilever 59 . Both the transverse cantilever 59 and the upper member 35 will include holes through which the bolts 45 pass with the nuts 47 and the washers 49 being used to fasten the bolts 45 in place, and to establish the size of the gap 67 . The bolts 45 are preferably welded to the transverse cantilever 59 . As such, the nuts 47 adjacent to transverse cantilever 59 shown in the figures may in some instances be eliminated as they are not necessary to prevent movement of the bolts 45 relative to the transverse cantilever 59 . It should be noted that the transverse cantilever 59 is rotatable relative to the upper member 35 in that the angle at which it extends from the support 31 can be adjusted using the adjustment assemblies 43 . It is contemplated that having adjustment assemblies that can be operated independently of each other so as to be able to adjust the slope of the transverse cantilever 59 in such a manner provides a number of advantages.
[0038] Referring to FIG. 7 , the sidewall ceiling support 33 comprises horizontal members 51 , portions of 57 and 63 , vertical members 53 , and cross-braces 55 . The members 51 , 53 , 57 , and 63 and braces 55 may be hollow or solid, comprise single pieces or an assembly of pieces, and/or comprise a single material or a plurality of materials. Moreover, the members 51 , 53 , 55 and 57 may be coupled together in any manner. However, in some instances it may be advantageous if the support 33 comprised aluminum tubing welded together such that the members 51 , 53 , and 55 , and a portion of the members 57 and 63 , form a rectangular frame with the cross-braces 55 extending between the internal corners of the frame.
[0039] Although the size and dimensions of the support 33 may vary between embodiments, it is advantageous to have the support 33 have a height (vertical length) at least equal to the height of the opening 7 , and to have a smaller width. If the slide-out 5 extends along most of the length of the side 19 of the hull 3 , a single support 33 may extend as shown between an edge of the opening 7 and the rear 15 of the hull 3 . In other instances, a plurality of adjacent supports 33 may extend between a side of the slide-out opening and the front 13 and/or the rear 15 of the hull 3 . In some instances, a slide-out opening may comprise supports 33 adjacent to both ends of the slide-out opening. It is contemplated that in some instances the support 33 will have a height between 79 and 96 inches and a width between 18 and 48 inches, and will be able to support static loads of at least 1200 pounds.
[0040] Although increased slide-out lengths are desirable, reducing the slide-out length in order to enable the support 33 to be positioned in an end portion of the side 19 adjacent to the opening 7 provides substantial improvement in the support provided to the ceiling assembly. Similarly, reducing slide-out depth enables the support 31 to be positioned perpendicular to the support 33 without interfering with the slide-out 5 as it is retracted, and possibly without interfering with a second slide out opposite the slide out 5 when both slide-outs are retracted.
[0041] Referring to FIGS. 3, 4 , 7 and 8 , the cambered tubular members 57 and 63 are positioned above the slide-out opening 7 and help counter any tendency of the upper edge of the opening 7 to sag. The members 57 and 63 are cambered such that there is a 0.5 to 1.5 inch gap C 1 between a center point of the member 57 and a line extending between the ends of the member 57 . This cambering is achieved by flexing the members 57 and 63 while they are adjacent to each other but not coupled together, and then welding the members 57 and 63 together to prevent them from sliding relative to each other such that they remain cambered. The member 57 and 63 are preferably at least as long as the length of the slide-out opening 7 . In some instances the length of the members 57 and 63 will be between 18 and 36 feet.
[0042] As can be seen, the members 57 and 63 , the support 31 , and the support 33 are all coupled together as part of the support frame 23 with the supports 31 and 33 being perpendicular to each other, and the support 33 and the members 57 and 63 being parallel or coplanar to each other. The support 33 incorporates an end of each of the members 57 and 63 which are welded together. The support 31 is coupled to transverse cantilever 59 which in turn is coupled to cambered member 63 .
[0043] In FIGS. 9-12 , a roller assembly is pictured which can add additional support to the cambered members 57 and 63 when the slide-out 5 is either fully retracted or fully extended. As shown, a roller assembly 69 is coupled to member 57 and is aligned with roller biasing members 65 and 67 which are coupled to an upper surface/ceiling of the slide-out 5 . Retracting the slide-out 5 places the roller biasing member 65 in contact with the roller assembly 69 so as to push the ceiling support 57 away from the slide-out 5 . Extending the slide-out 5 also places the roller biasing member 67 in contact with the roller assembly 69 so as to push the member 57 away from the slide-out 5 . As such, when retracted or extended, the slide-out 5 , roller assembly 69 , and one of the biasing members 65 and 67 function to push the member 57 upward. This has numerous advantages such as decreasing relative movement between the ceiling 9 and the slide-out 5 during travel, and providing additional support to the ceiling 9 .
[0044] It should be noted that the biasing member 67 extends further from the slide-out 5 than does the biasing member 65 . This permits the slide-out 5 to move downward relative to the rest of hull 3 such that a floor of the slide-out is substantially co-planar to the rest of the floor of the living area when the slide-out is extended even though the slide-out must be raised above the living area floor when the slide-out is retracted. As can be seen, the biasing member 67 is preferably a bracket that first extends upward against the wall 71 (which may function to stop movement of the slide-out 5 out of the living area 21 , and/or fills the gap left between the member 57 and the top of the slide-out 5 . The bracket has a sloped portion positioned to initially contact the roller assembly 69 as the slide-out 5 is extended. The biasing member 65 is preferably a solid block that has a sloped portion to initially contact the roller assembly 69 as the slide-out 5 is retracted.
[0045] A method of manufacturing a mobile recreational vehicle as described herein may include one or more of the following steps: (a) providing an elongated and adjustable ceiling support; (b) adjusting and positioning the support such that it has a desired height and extends between the floor assembly and the ceiling assembly; and (c) adjusting the height of the adjustable support to obtain a desired vertical dimension of at least a portion of the slide-out opening. In some instances, adjusting the height of the support may include rotating an elongated support member coupled to the adjustable support and extending between the adjustable support and an upper edge of the opening in the side wall. | A mobile recreational vehicle includes a body enclosing a living area designed to serve as self-contained living quarters during recreational travel. The body is supported on at least one pair of wheels (and often two or more pairs). The vehicle includes a ceiling assembly, a floor assembly; and an elongated and adjustable ceiling support extending between the ceiling assembly and the floor assembly wherein the height of the support can be adjusted during installation. In some instances, the vehicle has a shortened full length slide-out to allow for additional sidewall ceiling support, and in some instances has a slide-out opening that has cambered upper edges to minimize sagging the opening. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a pipelined SIMD-Systolic array processor and its methods. Especially, the present invention uses a way which combines both the broadcasting and the systolic structures to connect multiple pipelined processing elements together. Totally, the present invention accomplishes the design of an array processing architecture, which can process multiple data stream with single instruction stream, and its related computing methods. Moreover, the present invention can be applied to the design of parallel computers, video image processors, and digital signal processors. Meanwhile, the present invention can manipulate data transferring and shifting more efficiently, and also can be implemented on single VLSI chip. Thus, the present invention is full of practicability.
SUMMARY OF THE INVENTION
It is the primary object of the present invention, to provide a way for data input/output, data shifting, and data transferring. Thus, data processing can be faster and more efficiently.
Through efficient manipulation of data input/output, the present invention can save data lines and VLSI chip's pin-count. Moreover, the present invention avoids using complex control and uses the memory in an efficient manner. Thus, the present invention can be implemented on single VLSI chip. This is the secondary object of the present invention.
It is another object of the present invention to be designed as one-dimensional or two-dimensional array processor.
It is a further object of the present invention to be implemented on a VLSI chip and able to be installed directly on computers or televisions to accomplish various image processing functions. This means that the present invention is of practicability, of convenience, and of small size.
To achieve the previously described objects, the present invention mainly comprises registers, multiplexers and a number of processing elements, constructed as an array processing architecture. In the front and rear input/output ports, each processing element is also connected to registers and multiplexers. By cascading these registers and multiplexers together, the present invention can update the input data to each processing element by shifting. Therefore, reusable datum are not necessary to be reloaded every cycle from the multi-port memory. This can save the data loading time and the number of data lines, and, make the present invention easier to be implemented on a VLSI chip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram for the pipelined SIMD-Systolic array processing architecture of the present invention.
FIG 2 is a schematic circuit diagram for the processing elements of the present invention.
FIG. 3 is the input/output truth table for the mode-control ROM of the processing elements of the present invention.
FIG. 4 is the first operational mode for the processing elements of the present invention.
FIG. 5 is the second operational mode for the processing elements of the present invention.
FIG. 6 is the third operational mode for the processing elements of the present invention.
FIG. 7 is the fourth operational mode for the processing elements of the present invention.
FIG. 8 is the fifth operational mode for the processing elements of the present invention.
FIG. 9 is the sixth operational mode for the processing elements of the present invention.
FIG. 10 is a schematic circuit diagram of the present invention for processing matrix multiplication computation.
FIG. 11 is a cycle-based data and control signal diagram of the present invention for loading constant data into the processing elements during processing matrix multiplication computation.
FIGS. 12A & 12B are cycle-based data and control signal diagram of the present invention for processing matrix computation.
FIG. 13 is a schematic circuit diagram of the present invention for processing finite-impulse response Filtering Computation.
FIG. 14 is a cycle-based data and control signal diagram of the present invention for processing finite-impulse-response filtering computation.
FIG. 15 is a schematic circuit diagram of the present invention for processing infinite-impulse-response filtering computation.
FIG. 16 is a cycle-based data and control signal diagram of the present invention for processing infinite-impulse-response filtering computation.
FIG. 17 is a schematic circuit diagram of the present invention for processing edge-detection and smoothing computation.
FIGS. 18A, 18B & 19 represent cycle-based data and control signal diagrams of the present invention for processing edge-detection and smoothing computation.
FIG. 20 is a schematic circuit diagram of the present invention for processing two-dimensional discrete cosine transform.
FIG. 21 is a cycle-based data signal diagram of the present invention for loading constant data into the processing elements during processing two-dimensional discrete cosine transform.
FIGS. 22 & 23 represent a cycle-based data and control signal diagram of the present invention for processing the two-dimensional discrete cosine transform.
FIG. 24 is a schematic circuit diagram for two-dimensional array processing architecture of the present invention.
FIG. 25 represents an implementation of two-dimensional array processing architecture of the present invention.
FIG. 26 is a cycle-based data and control signal diagram of the present invention for loading constant data into the processing elements of the two-dimensional array architecture shown as FIG. 25 for processing the two-dimensional discrete cosine transform.
FIGS. 27 & 28 represent cycle-based data and control signal diagrams of the present invention for processing the two-dimensional discrete cosine transform by the two-dimensional array architecture shown as FIG. 25.
FIG. 29 is a schematic circuit diagram for two-dimensional array processing architecture of the present invention for processing image template matching and motion estimation.
FIG. 30 represents an implementation of two-dimensional array processing architecture of the present invention for processing image template matching and motion estimation.
FIGS. 31A, 31B & 32 represent cycle-based data and control signal diagrams of the present invention for processing image template matching and motion estimation by the two-dimensional array architecture shown as FIG. 30.
FIG. 33 shows that the array processing architecture of the present invention can be cascaded to form stage-pipelined architectures.
FIG. 34 shows how the array processing architectures of the present invention are cascaded to form a stage-pipelined architecture to compute 1008-point discrete Fourier transform.
FIG. 35 shows how the array processing architectures of the present invention can be combined with systolic architectures.
FIG. 36 shows how the array processing architectures of the present invention can be applied to the implementation of image compression systems.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the present invention mainly comprises a number of processing elements PE1˜PEn, which constructed as an array (processing) architecture, a broadcasting register rb, shift register arrays rs11˜rs1n, rs21˜rs2n, ro1˜ron, multiplexers Mu11˜Mu1n, Mu21˜Mu2n, Mb, MO1˜MOn, MOb, a multiport memory M, and a controller C. At the input ports the processing elements PE1˜PEn are connected to the registers rs11˜rs2n, rs21˜rs2n, rb through the multiplexers Mu11˜Mu1n, Mu21˜Mu2n, Mb.
At the output ports the processing elements PE1˜PEn are connected to the registers ro1˜ron through the multiplexers MO1˜MOn, MOb. Moreover, the multiport memory M is connected to the registers rs21, rs11, rb, ro1. Then, all of the components of the present invention are controlled by the controller C. The control signals sent out from the controller C are presented as follows:
Control signal 1: the shift/load control signal for the shift register array rs21˜rs2n.
Control signal 2: the clear control signal for the shift register array rs21˜rs2n.
Control signal 3: the shift/load control signal for the shift register array rs11˜rs1n.
Control signal 4: the clear control signal for the shift register array rs11˜rs1n.
Control signal 5: the data-select control signal for multiplexers Mu11˜Mu1n.
Control signal 6: the data-select control signal for multiplexers Mu21˜Mu2n.
Control signal 7: the data-select control signal for the multiplexer Mb to select broadcasting data.
Control signal 8: the load control signal for the broadcasting register rb.
Control signal 9: the function control signals for the processing elements PE1˜PEn.
Control signal 10: the reset control signal for the processing elements PE1˜PEn.
Control signal 11: the shift/load control signal for the shift register array ro1˜ron.
Control signal 12: the data-select control signal for the multiplexers MO1˜MOn.
Control signal 13: the data-select control signal for the multiplexer MOb.
Control signal 14: Control signals for the multiport memory which include addresses, Read/Write, Enable, etc.
Data and Control signal 15: data and control signals from an external processor to the multiport memory.
Data signal 16: data signals to other external functional unit.
Control signal 17: control signals to other external function unit.
According to the data processing operations of the present invention, input datum are transferred to the processing elements PE1˜PEn for processing under the control of control signals 1˜8. The action of these control signals is described in the following.
If the control signal 2 is of logic one, the content of registers rs21˜rs2n would be cleared as logic zero;
if the control signal 1 is of logic one, register rs2n would be loaded with the content of register rs2(n-1), where n>1, and register rs21 would be loaded with the value of ms2 which is read from the multiport memory M;
if the control signal 4 is of logic one, the content of registers rs11˜rs1n would be cleared as logic zero;
if the control signal 3 is of logic one, register rs1n would be loaded with the value of is(n-1), where n>1, and register rs11 would be loaded with the value of ms1 which is read from the multiport memory M. Multiplexers Mu11˜Mu1n are controlled by control signal 5 and multiplexers Mu21˜Mu2n are controlled by control signal 6. These multiplexers are used to generate isn from rs2n, rs1n, Oin in the following way.
If the control signal 6 is of logic zero, isn is equal to the content of rs2n;
if the control signal 6 is of logic one and the control signal 5 is of logic one, isn is equal to the content of rs1n;
if the control signal 6 is of logic one and the control signal 5 is of logic zero, isn is equal to the content of Oin.
Additionally, the control signal 8 is to control the loading of broadcasting register rb with Mb which is read from the multiport memory M. If the control signal 8 is of logic one, register rb would be loaded with Mb. Control signal 7 is to control the multiplexer Mb to generate the broadcasting data to the processing elements PE1˜PEn from rb and Ob, where Ob is the broadcasting output data from the processing elements PE1˜PEn.
If the control signal 7 is of logic one, the broadcasting data signal ib is equal to the content of register rb; if the control signal 7 is of logic zero, the broadcasting data signal ib is equal to Ob. The output control of the present invention is through the control of control signals 11˜13. The control method is similar to what has been described for the input control. If the control signal 11 is of logic one, registers ron, where n>1, is loaded with the data from multiplexers MOn and register rob is loaded with the data from MOb and MO1. If both the control signals 12 and 13 are of logic one, registers ron would be loaded with ro(n+1); if the control signal 12 is of logic zero and the control signal 13 is of logic one, registers ron would be loaded with On; if the control signal 13 is of logic zero, register ro1 would be loaded with Ob.
Finally, control signal 14 is for the control of multiport memory M to read and write data.
As shown in FIG. 2, the pipelined processing element, PE, of the present invention comprises first-in first-out memory 100, constant register file 101, multiplexers 102, 103, 108 and 114, registers 106, 107 and 110, multiplier 104, absolute-difference unit 105, adder 109, data register file 113, tristate buffer 111, and decoder 112. Meanwhile, control signal 9 from the controller C are for the function control of the processing element and can be further divided into the following subgroups first-in first-out memory control 91, operational mode control 92, register-load control 93, adder control 94, identification control 95, constant register file control 96, data register file control 97.
For operational mode control, there is a read-only memory 921 to generate the control signals C0˜C7 from the mode control 92.
As shown in FIG. 3, there are six operational modes for running the processing element.
Referring to FIG. 2, C0, C1 are to control the multiplexer 102; C2, C3, C4 are to control the multiplexer 103; C5, C6 are to control the multiplexer 108; C7 is to control the multiplexer 114. Thus, by using mode control 92, the processing element can change the operational mode. Totally, through controlling the internal data flow paths, each processing element of the present invention can have six operational modes. FIGS. 4, 5, 6, 7, 8, 9 show the schematic block diagrams for each operational mode respectively. With these operational modes, the array processing architecture of the present invention can manipulate various operations more efficiently.
As for the other control signals, their functions are explained as follows:
911: the read control signal for the first-in first-out memory 100;
912: the write control signal for the first-in first-out memory 100;
913: the reset control signal for the first-in first-out memory 100;
931: the load control signal for the register 106;
932: the load control signal for the register 107;
933: the load control signal for the register 110;
94: the function control signal for the adder 109;
95: the identification control for the processing element and the input of the decoder 112;
951: the switch control of the tristate buffer 111;
961: the read control signal for the constant register file 101;
962: addresses for read operation for the constant register file 101;
963: the write control signal for the constant register file 101;
964: addresses for write operation for the constant register file 101;
971: the read control signal for the data register file 113;
972: addresses for read operation for the data register file 113;
973: the write control signal for the data register file 113;
974: addresses for write operation for the data register file 113;
As shown in FIG. 10, the array processing architecture is the embodiment of the present invention for processing the matrix computation. For explanation, only two processing elements are included. During processing the matrix computation, the processing elements of the present invention are all in the first operational mode, shown as FIG. 4, through the control of controller C. Also, control signals 5, 6, 7, 13 are all in the state of logic one. Thus, multiplexers Mu11˜Mu1n, Mu21˜Mu2n, Mb, MOb are in the data transferring state as shown in FIG. 10. Here the following matrix computation is used as an example for explaining how the present invention can process the matrix computation. ##EQU1##
In order to process the matrix computation shown above, first of all, the present invention loads the processing element PE1 with constant data a00, aO1, a02, a03, a20, a21, a22, a23 and loads the processing element PE2 with constant data a10, a11, a12, a13, a30, a31, a32, a33. Referring to FIG. 11, the constant data are loaded into the processing elements through registers rs11, rs12, and, the loading operation is controlled by control signals 3, 963, 964. The control signal 3 is always in the state of logic one. Therefore, registers rs11, rs12 can shift and load data from the multiport memory M to the processing elements. In the first cycle, load data a10 into register rs11. In the next cycle, load data a00 into register rsll and data a10 would propagate to register rs12. Then, when data a11 is coming, data a00, a10 which are now stored in registers rsll and rs12 respectively would be transferred into processing elements PE1 and PE2 individually. AT this time, the write control signal 963 for the contant register file 101 would be in the state of logic one. Continuously doing in this way, the processing element PE1 would eventually be loaded with data a00, aO1, a02, a03, a20, a21, a22, a23, and, the processing element PE2 loaded with data a10, a11, a12, a13, a30, a31, a32, a33.
As to the processing of matrix computation, FIGS. 12A and 12B show the internal operation of the processing elements PE1, PE2 and the broadcasting register rb cycle by cycle during the computation.
According to the matrix computation shown above, the computational results are as follows:
y00=a00 x00+a01 x10+a02 x20+a03 x30
y10=a10 x00+a11 x10+a12 x20+a13 x30
y20=a20 x00+a21 x10+a22 x20+a23 x30
y30=a30 x00+a31 x10+a32 x20+a33 x30
y01=a00 x01+a01 x11+a02 x21+a03 x31
y11=a1O xO1+a11 x11+a12 x21+a13 x31
y21=a20 x01+a21 x11+a22 x21+a23 x31
y31=a30 x01+a31 x11+a32 x21+a33 x31
The data [aij]have been preloaded into the processing elements PE1, PE2. Therefore, during processing the matrix computation, data x00 is first transferred into register rb from the memory M. Meanwhile, data a00, a10, are read from constant register file 101 in the processing elements PE1 and PE2. Therefore, through the operation of multiplier 104, the processing elements PE1 and PE2 load register 106 with a00 x00 and a10 x00 individually. Then, in the next cycle, the output of Adder 109 of PE1, PE2 would be equal to a00 x00, a10 x00 respectively. At this time, the adder control signal 94 is in the state of logic one. Also, the output of the multiplier 104 of PE1, PE2 would be equal to a01 x10 and all x10 respectively. Then, in the next cycle, the content of registers 106, 110 of PE1, PE2 would be a01 x1O, a00 x00 and a11 x10, a10 x00 respectively. Continuously doing in this way, the output of adder 109 of PE1, PE2 would be equal to y00, y10 eventually. Meanwhile, the control signal 12 is in the state of logic zero in order to load y00, y10 into registers ro1 ro2 respectively. Then, in the following cycles, during computing y20, y30, y00, y10 are shifted into the memory M. Referred to FIG. 12, the present invention processes the matrix computation in a way similar to what has been described.
As shown in FIG. 13, the array processing architecture is the embodiment of the present invention for processing the finite-impulse-response filtering computation. Under the control of controller C, the processing elements are running in the second operational mode shown as FIG. 5. Meanwhile, control signals 5, 7, 13 are in the state of logic one and control the multiplexers Mu11˜Mu1n, Mb, MOb. As an example, FIG. 13 shows the resulted architecture with two processing elements PE1, PE2. Also, the data processing for computing for explaining according to:
yi=a0 xi+a1 xi-1+a2 xi-2+a3 xi-3
is presented
yi=a0 xi+a1 xi-1+a2 xi-2+a3 xi-3,
the computational results would be as follows:
y0=a0 x0+a1 x-1+a2 x-2+a3 x-3
y1=a0 x1+a1 x0+a2 x-1+a3 x-2
y2=a0 x2+a1 x1+a2 x0+a3 x-1
y3=a0 x3+a1 x2+a2 x1+a3 xO
y4=a0 x4+a1 x3+a2 x2+a3 x1
y5=a0 x5+a1 x4+a2 x3+a3 x2
and so forth
Referred to FIG. 14, during computing yi, the present invention uses registers rs21, rs22, rs11, rs12 and multiplexers Mu21, Mu22, which are controlled by control signal 6, to transfer input data [xm]to the processing elements PE1, PE2. Meanwhile, constant data [an]is broadcasted through register rb to the processing elements PE1, PE2.
Also, the computational results yi are transferred to the memory M through registers r01, r02 and multiplexers M01, M02, which are controlled by control signal 12.
As to data transferring and processing, it would be explained as follows:
Initially, data x1 is loaded from the multiport memory M into register rs21. Then, in the next cycle, register rs21 is loaded with data x0 and register rs22 is loaded with data x1. At this time, control signal 6, which controls multiplexers Mu21, Mu22, is in the state of logic zero. Therefore, is1, is2, which are input ports of processing elements PE1, PE2 respectively, are of value x0, x1 individually. Also, register rb is loaded with data aO so that the output of multiplier 104 is a0x0 for PE1 and a0x1 for PE2. One cycle later, control signal 6 would change to logic one, and, input data xn are transferred to PE1, PE2 through rs11, rs12. Continuously doing in this way, the output of adder 109 would become y0 for PE1 and y1 for PE2. At this time, control signal 12 is set to logic zero.
One cycle later, yo, y1 would be loaded into ro1 ro2 respectively. Then, control signal 12 is set to logic one and y0, y1 are transferred to multiport memory M or other functional unit through registers ro1, ro2. In such way the computational results for finite-impulse-response filtering would be generated.
As shown in FIG. 15, the array processing architecture is the embodiment of the present invention for processing the infinite-impulse-response filtering computation. Under the control of controller C, the processing elements are running in the second operational mode shown as FIG. 5. Moreover the data signal ob is used for broadcasting the intermediate results to the processing elements through multiplexer Mb. Meanwhile, control signals 2, 6, 7, 12 are used for clearing registers rs21, rs22, controlling multiplexers Mu21, Mu22, controlling multiplexer Mb, and controlling multiplexers MO1, MO2 respectively. FIG. 15 shows the resulted architecture with two processing elements PE1, PE2. Except the circuits for feedback signal Ob, the architecture shown in FIG. 15 is the same as that in FIG. 13 for finite-impulse-response filtering computation. In the following the data processing for computing yi+b1 yi-1+b2 yi-2+b3 yi-3=a0 xi+a1 xi-1+a2 xi-2+a3 xi-3 is presented for explanation. Therefore, the computational results would be as follows:
y0=-b1y-1-b2y-2-b3y-3+a0x0+a1x-1+a2x-2+a3x-3
y1=-b1y0-b2y-1-b3y-2+a0x1 +a1x0+a2x-1+a3x-2
y2=-b1y1-b2y0-b3y-1+a0x2+a1x1+a2x0+a3x-1
y3=-b1y2-b2y1-b3y0+a0x3+a1x2+a2x1+a3x0
and so forth
Referred to FIG. 16, it shows that the present invention uses the processing element PE1 to compute y0, y2, y4, . . . and the processing element PE2 to compute y1, y3, y5, . . . As for data transferring and processing, it would be explained as follows:
Initially, data x1 is loaded from the multiport memory M into register rs21. Then, in the next cycle, register rs21 is loaded with data x0 and data x1 is transferred from register rs21 to register rs22. At this time, control signal 6, which controls multiplexers Mu21, Mu22, is in the state of logic zero. Therefore, is1, is2 are of value x0, x1 individually. Meanwhile, register rb is of value a0 so that the output of multiplier 104 is a0x0 for PE1 and a0x1 for PE2. In the next cycle, control signal 6 would change to logic one. Then, data xn are transferred to PE1, PE2 through rs11, rs12. During the computation, control signal 2 is set to logic one, when data signals 01, 02 of PE1, PE2 are equal to a0x0+a1x-1, a0x1+a1x0 respectively, to clear registers rs21, rs22. Then, in the following cycles, data -bn are transferred to processing elements PE1, PE2 through the cooperation of registers rs21, rs22, rs11, rs12 and multiplexers Mu21, Mu22. On the other hand, ym are sent to PE1, PE2 by broadcasting. After y0 is computed, it is broadcasted to PE1, PE2 to compute y1. Then, y0, y1 are transferred to registers r01, r02, by setting control signal 12 to logic zero, and shifted to multiport memory M in the following cycles. Continuously doing in this way, the computational results for infinite-impulse-response filtering would be generated.
As shown in FIG. 17, the array processing architecture is the embodiment of the present invention for processing the computation of edge detection and smoothing. Under the control of controller C, the processing elements are running in the second operational mode shown as FIG. 5. Moreover, the first-in first-out memory 100 is used as data buffer. FIG. 17 shows the resulted architecture with four processing elements PE1, PE2, PE3, PE4. Also, the following computation is used for explanation:
y30=x50 w20+x51 w21+x52 w22
y31=x51 w20+x52 w21+x53 w22+x40 w10+x41 w11+x42 w12+x41 w10+x42 w11+x43 w12+x30 w00+x31 w01+x32 w02+x31 w00+x32 w01+x33 w02
y20=x40 w20+x41 w21+x42 w22
y21=x41 w20+x42 w21+x43 w22+x30 w10+x31 w11+x32 w12+x31 w10+x32 w11+x33 w12+x20 w00+x21 w01+x22 w02+x21 w00+x22 wO1+x23 w02
y10=x30 w20+x31 w21+x32 w22
y11=x31 w20+x32 w21+x33 w22+x20 w10+x21 w11+x22 w12+x21 w10+x22 w11+x23 w12+x10 w00+x11 w01+x12 w02+x11 w00+x12 w01+x13 w02
y00=x20 w20+x21 w21+x22 w22
y01=x21 w20+x22 w21+x23 w22+x10 w10+x11 w11+x12 w12+x11 w10+x12 w11+x13 w12+x00 w00+x01 w01+x02 w02+x01 w00+x02 w01+x03 w02
During data processing, the processing element PE1 is used to compute y30, y31; PE2 is to compute y20, y21; PE3 is to compute y10, y11; PE4 is to compute y00, y01. Referred to FIGS. 18A, 18B, and 19, the data transferring and processing can be explained as follows:
Initially, data x30, x20, x10, x00 are loaded into registers rs21, rs22, rs23, rs24 from multiport memory by shifting. At this time, control signal 6, which controls multiplexers Mu21, Mu22, Mu23, Mu24, is set to logic zero. Therefore, is1, is2, is3, is4 are of value x30, x20, x10, x00 respectively. Meanwhile, register rb is of value w00 so that the output of multiplier 104 is x30w00, x20w00, x10w00, x00w00 for processing elements PE1, PE2, PE3, PE4 individually.
During the following cycles, control signal 6 is set to logic one. Then x40, x50 are shifted through register rs11 and registers rs21, rs22, rs23, rs24 are for preloading x01, x11, x21, x31. Continuously doing in this way, y30, y20, y10, y00 would be computed by PE1, PE2, PE3, PE4. Also, during computing y30, y20, y10, y00, data x31, x32 would be stored in the first-in first-out memory 100 of PE1 through the control of write control signal 912. Similarly, data x21, x22, x11, x12, x01, x02 are stored in the first-in first-out memory 100 of PE2, PE3, PE4 respectively, In this way, during computing y31, y21, y11, y01, data x31, x21, x11, x01 are read from first-in first-out memory 100 instead of registers rs21, rs22, rs23, rs24. Therefore, only data x33, x23, x13, x03 are loaded through registers rs21, rs22, rs23, rs24. This can save a lot of data loading time when y32, y22, y12, y02, y33, y23, y13, y03, etc. are also computed. During computing yij, constant data wkl, O≦k, 1<3, are sent to the processing elements through register rb by broadcasting. Also, yij are shifted to multiport memory M or other functional unit through registers ro1, ro2, ro3, ro4 and multiplexers MO1, MO2, MO3, MO4 under the control of control signal 12.
As shown in FIG. 20, the array processing architecture is the embodiment of the present invention for processing the two-dimensional discrete cosine transform. Under the control of controller C, the processing elements are running in the first operational mode shown as FIG. 4. Moreover, constant register file 101, data register file 113, decoder 112, tristate buffer 111 are also involved in this computation. Here, the following computation is used as an example for explanation: ##EQU2## where T represents transposition.
This is to compute [zij]which is the two-dimensional discrete cosine transform of the 3×3 matrix [xij].
The first step is to compute column--transform, ##EQU3## then, compute the row--transform, ##EQU4##
Referred to FIG. 21, FIG. 22 and FIG. 23, the loading of data, data processing and the operation of control signals can be explained as follows:
As shown in FIG. 21, first of all, data aij are loaded into the constant register file 101 in the processing elements PE1, PE2, PE3. Then, shown as FIG. 22, data xij are loaded from multiport memory M into register rb by the following sequence:
x00, x1O, x20, x01, x11, x21, x02, x12, x22.
In this way, processing element PE1 would compute y00, y01, y02, PE2 would compute y10, y11, y12, and PE3 would compute y20, y21, y22. Afterwards, by using decoder 112 to generate control signal to control tristate buffer 111, yij would be sent back to the input ib of the processing elements through multiplexer Mb by the following sequence:
y00, y01, y02, y10, y11, y12, y20, y21, y22.
Finally, the two-dimensional discrete cosine transform would be computed.
As shown in FIG. 24, the array processing architecture is the two-dimensional embodiment of the present invention. As an example, shown as FIG. 25, six processing elements PE11, PE12, PE21, PE22, PE31, PE32 are used to explain the process of computing the two-dimensional discrete cosine transform. Referred to FIG. 26, FIG. 27, and FIG. 28, data loading, control sequence of control signals, and operational method can be explained as follows: as shown in FIG. 26, first of all, data aij are loaded into the constant register files 101 in the processing elements PE11, PE21, PE31, PE12, PE22, PE32. Then, shown as FIG. 27, data xij are loaded from multiport memory M into register rb by the following sequence:
x00, x1O, x20, x01, x11, x21, x02, x12, x22.
In this way, processing element PEll would compute y00, y01, y02, PE21 would compute y10, y11, y12, and PE31 would compute y20, y21, y22. Afterwards, shown as FIG. 28, by using decoder 112 to generate control signal to control tristate buffer 111, yij computed by PE11, PE21, PE31 would be sent to the input ib of the processing elements PE12, PE22, PE32 by the following sequence:
y00, y01, y02, y1O, y11, y12, y20, y21, y22.
Then, processing element PE12 would compute Z00, Z10, Z20, PE22 would compute ZO1, Z11, Z21, and PE32 would compute Z02, Z12, Z22. In this way, the two-dimensional array processing architecture can achieve the effect of processing the two-dimensional discrete cosine transform.
As shown in FIG. 29, the array processing architecture is a two-dimensional embodiment, which comprises n×m processing elements, of the present invention for processing the operations of motion estimation and template matching . Here, P1, P2, Pm represent programmable delays. As an example, shown as FIG. 30, a 3×3 processing array is used to explain the operation. Here, P1, P2 are 3-clock-cycle delays. Moreover, the processing elements PE11, PE12, PE13, PE21, PE22, PE23, PE31, PE32, PE33 are running under the sixth operational mode which is shown as FIG. 9. For explanation, the following computation is used as an example: ##EQU5##
Referred to FIGS. 31A, 31B, and 32, processing element PE11 is used to compute z20, PE21, PE31 are to compute z10, z00 respectively, PE12, PE22, PE32 are to compute z21, z11, z01 respectively, and PE13, PE23, PE33 are to compute z22, z12, z02 respectively. Totally, this array processing architecture can achieve the function of processing both motion estimation and template matching.
As shown in FIG. 33, the array processing architecture is a stage-pipelined embodiment of the present invention. Such an array processing architecture comprises n pipelined SIMD-Systotic array processing architectures, which are cascaded in a pipelined manner, and is called stage-pipelined architecture. Also, such architecture can be combined with a general purpose processor 1001 to enhance its computational performance. Shown as FIG. 34, the computation of 1008-point discrete Fourier transform is used as an example for explanation. A general purpose processor 1001 is cascaded with three pipelined SIMD-Systolic array processing architectures 3000, 3001, 3002 which are for computing 7-point, 9-point, 16-point discrete Fourier transform respectively. By using such an architecture, the 1008-point discrete Fourier transform can be computed with a high computational performance. As shown in FIG. 35, the array processing architecture is an embodiment of combining the present invention with systolic architecture which comprises of multiple processing elements. Referred to FIG. 35, a group of processing elements PE1˜PEn, which form a systolic architecture 4002, is added between pipelined SIMD-Systolic array processing architectures 4000 and 4001. Also, such an architecture can be combined with a general purpose processor. Referred to FIG. 36, the implementation of an image compression system is used as an example for explanation. Two pipelined SIMD-Systolic array processing architectures 5000, 5001, which compute two-dimensional discrete cosine transform and inverse discrete cosine transform individually, are combined with a systolic architecture 5002 in one end and with a general purpose processor 1001 in the other end. Also, the systolic architecture 5002 comprises quantizer PE11, Zig-Zag scan processor PE21, coder PE31, dequantizer PE12, inverse Zig-Zag scan processor PE22, decoder PE32 and multiplexer Mu1. All of the processing elements in the systolic architecture 5002 are cascaded systolically. Meanwhile, control signal 19 is to choose the operational mode. If control signal 19 is of logic one, data input of dequantizer PE12 is from the output of quantizer PE11. Therefore, the whole system is running the encoding process. 0n the other hand, the control signal 19 is of logic zero, data input of dequantizer PE12 is from the output of inverse Zig-Zag scan processor PE22. Then, the whole system is running the decoding process.
In such manner, the effect of image compression function can be achieved.
As described above, the present invention is related to pipelined SIMD-Systolic array processing architecture and its computing methods.
The present invention controls data processing, data transferring and data input/output in a concurrent manner. Therefore, computational performance can be increased. Also, the present invention can save data lines and increase the memory efficiency.
Therefore, it is possible to fabricate the present invention on single VLSI chip. Totally, the present invention of practicability to the industry. | A pipelined SIMD-systolic array processor and its methods, mainly comprising a number of processing elements constructed as array architecture, multiport memory, registers, multiplexers, and controller, wherein the registers and multiplexers are connected for transferring data between the multiport memory and processing elements, the methods thereof uses a way which combines both broadcasting and systolic structures for transferring data into and out each processing element, and moreover, the method uses the controller to manipulate data transferring and the operation of each processing element for various functions; the array processor can have a faster processing speed and, through using a multiport memory, each processing element requires only a small amount of storage, and therefore, the array processor can use memory in a more efficient way. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/627,260, filed Jul. 24, 2003, which claimed the benefit of U.S. Provisional Application No. 60/399,012, filed Jul. 26, 2002, the disclosures of which are incorporated fully herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is generally directed to implantable medical devices, in particular to a tool for implanting electrodes and their association wires.
BACKGROUND OF THE INVENTION
[0003] In 1755 LeRoy passed the discharge of a Leyden jar through the orbit of a man who was blind from cataract and the patient saw “flames passing rapidly downwards.” Ever since, there has been a fascination with electrically elicited visual perception. The general concepts of electrical stimulation of retinal cells to produce these flashes of light or phosphenes has been known for quite some time. Based on these general principles, some early attempts at devising a prosthesis for aiding the visually impaired have included attaching electrodes to the head or eyelids of patients. While some of these early attempts met with some limited success, these early prosthesis devices were large, bulky and could not produce adequate simulated vision to truly aid the visually impaired.
[0004] In the early 1930's, Foerster investigated the effect of electrically stimulating the exposed occipital pole of one cerebral hemisphere. He found that, when a point at the extreme occipital pole was stimulated, the patient perceived a small spot of light directly in front and motionless (a phosphene). Subsequently, Brindley and Lewin (1968) thoroughly studied electrical stimulation of the human occipital cortex. By varying the stimulation parameters, these investigators described in detail the location of the phosphenes produced relative to the specific region of the occipital cortex stimulated. These experiments demonstrated: (1) the consistent shape and position of phosphenes; (2) that increased stimulation pulse duration made phosphenes brighter; and (3) that there was no detectable interaction between neighboring electrodes which were as close as 2.4 mm apart.
[0005] As intraocular surgical techniques have advanced, it has become possible to apply stimulation on small groups and even on individual retinal cells to generate focused phosphenes through devices implanted within the eye itself. This has sparked renewed interest in developing methods and apparati to aid the visually impaired. Specifically, great effort has been expended in the area of intraocular retinal prosthesis devices in an effort to restore vision in cases where blindness is caused by photoreceptor degenerative retinal diseases such as retinitis pigmentosa and age related macular degeneration which affect millions of people worldwide.
[0006] Neural tissue can be artificially stimulated and activated by prosthetic devices that pass pulses of electrical current through electrodes on such a device. The passage of current causes changes in electrical potentials across neuronal membranes, which can initiate neuron action potentials, which are the means of information transfer in the nervous system.
[0007] Based on this mechanism, it is possible to input information into the nervous system by coding the information as a sequence of electrical pulses which are relayed to the nervous system via the prosthetic device. In this way, it is possible to provide artificial sensations including vision.
[0008] One typical application of neural tissue stimulation is in the rehabilitation of the blind. Some forms of blindness involve selective loss of the light sensitive transducers of the retina. Other retinal neurons remain viable, however, and may be activated in the manner described above by placement of a prosthetic electrode device on the inner (toward the vitreous) retinal surface. This placement must be mechanically stable, minimize the distance between the device electrodes and the neurons, and avoid undue compression of the neurons.
[0009] In 1986, Bullara (U.S. Pat. No. 4,573,481) patented an electrode assembly for surgical implantation on a nerve. The matrix was silicone with embedded iridium electrodes. The assembly fit around a nerve to stimulate it.
[0010] Dawson and Radtke stimulated cat's retina by direct electrical stimulation of the retinal ganglion cell layer. These experimenters placed nine and then fourteen electrodes upon the inner retinal layer (i.e., primarily the ganglion cell layer) of two cats. Their experiments suggested that electrical stimulation of the retina with 30 to 100 uA current resulted in visual cortical responses. These experiments were carried out with needle-shaped electrodes that penetrated the surface of the retina (see also U.S. Pat. No. 4,628,933 to Michelson).
[0011] The Michelson '933 apparatus includes an array of photosensitive devices on its surface that are connected to a plurality of electrodes positioned on the opposite surface of the device to stimulate the retina. These electrodes are disposed to form an array similar to a “bed of nails” having conductors which impinge directly on the retina to stimulate the retinal cells. Such a device increases the possibility of retinal trauma by the use of its “bed of nails” type electrodes that impinge directly on the retinal tissue.
[0012] The art of implanting an intraocular prosthetic device to electrically stimulate the retina was advanced with the introduction of retinal tacks in retinal surgery. De Juan, et al. at Duke University Eye Center inserted retinal tacks into retinas in an effort to reattach retinas that had detached from the underlying choroid, which is the source of blood supply for the outer retina and thus the photoreceptors. See, e.g., E. de Juan, et al., 99 Am. J. Ophthalmol. 272 (1985). These retinal tacks have proved to be biocompatible and remain embedded in the retina, and choroid/sclera, effectively pinning the retina against the choroid and the posterior aspects of the globe. Retinal tacks are one way to attach a retinal array to the retina.
[0013] The retina is extraordinarily fragile. In particular, retinal neurons are extremely sensitive to pressure; they will die if even a modest intraocular pressure is maintained for a prolonged period of time. Glaucoma, which is one of the leading causes of blindness in the world, can result from a chronic increase of intraocular pressure of only 10 mm Hg. Furthermore, the retina, if it is perforated or pulled, will tend to separate from the underlying epithelium, which will eventually render it functionless. Thus attachment of a conventional prosthetic retinal electrode device carries with it the risk of damage to the retina, because of the pressure that such a device could exert on the retina.
[0014] Byers, et al. received U.S. Pat. No. 4,969,468 in 1990 which disclosed a “bed of nails” electrode array which in combination with processing circuitry amplifies and analyzes the signal received from the tissue and/or which generates signals which are sent to the target tissue. The penetrating electrodes are damaging to the delicate retinal tissue of a human eye and therefore are not applicable to enabling sight in the blind.
[0015] In 1992 U.S. Pat. No. 5,109,844 issued to de Juan et al. on a method of stimulating the retina to enable sight in the blind wherein a voltage stimulates electrodes that are in close proximity to the retinal ganglion cells. A planar ganglion cell-stimulating electrode is positioned on or above the retinal basement membrane to enable transmission of sight-creating stimuli to the retina. The electrode is a flat array containing 64-electrodes.
[0016] Norman, et al. received U.S. Pat. No. 5,215,088 in 1993 on a three-dimensional electrode device as a cortical implant for vision prosthesis. The device contains perhaps a hundred small pillars each of which penetrates the visual cortex in order to interface with neurons more effectively. The array is strong and rigid and may be made of glass and a semiconductor material.
[0017] U.S. Pat. No. 5,476,494, issued to Edell, et al. in 1995, describes a retinal array held gently against the retina by a cantilever, where the cantilever is anchored some distance from the array. Thus the anchor point is removed from the area served by the array. This cantilever configuration introduces complexity and it is very difficult to control the restoring force of the cantilever due to varying eye sizes.
[0018] Sugihara, et al. received U.S. Pat. No. 5,810,725 in 1998 on a planar electrode to enable stimulation and recording of nerve cells. The electrode is made of a rigid glass substrate. The lead wires which contact the electrodes are indium tin oxide covered with a conducting metal and coated with platinum containing metal. The electrodes are indium tin oxide or a highly electrically conductive metal. Several lead-wire insulating materials are disclosed including resins.
[0019] U.S. Pat. No. 5,935,155, issued to Humayun, et al. in 1999, describes a visual prosthesis and method of using it. The Humayun patent includes a camera, signal processing electronics and a retinal electrode array. The retinal array is mounted inside the eye using tacks, magnets, or adhesives. Portions of the remaining parts may be mounted outside the eye. The Humayun patent describes attaching the array to the retina using retinal tacks and/or magnets. This patent does not address reduction of damage to the retina and surrounding tissue or problems caused by excessive pressure between the retinal electrode array and the retina.
[0020] Mortimer's U.S. Pat No. 5,987,361 of 1999 disclosed a flexible metal foil structure containing a series of precisely positioned holes that in turn define electrodes for neural stimulation of nerves with cuff electrodes. Silicone rubber may be used as the polymeric base layer. This electrode is for going around nerve bundles and not for planar stimulation.
[0021] The retina is also very sensitive to heat. Implanting a retinal prosthesis fully within the eye may cause excessive heat buildup damaging the retina. It is, therefore, advantageous to implant an electrode array on the retina attached by a cable to heat producing electronics which are implanted somewhere outside the eye. If no electronics are implanted in the eye, it is necessary to run one wire for each electrode from the electronics package to the electrode array. These wires must be extremely thin. While grouping them together in a cable with a protective sheath provides some protection, the array and cable must be handled carefully to prevent damage to the electrode array or cable.
[0022] Published U.S. patent application 2002/0099420, Chow et al. describes a surgical tool for implantation of a retinal electrode array. The Chow device is a tube which is placed into the eye and to the implant location. Then fluid flows though the tube pushing the electrode array into place.
SUMMARY OF THE INVENTION
[0023] The present invention is a surgical tool for implanting an electrode array and its connected cable within an eye. The insertion tool is used to aid the surgeon in pulling the electrode wire and array through the scull, four-rectus muscles of the eye, and the sclera. The insertion tool consists of a medical grade ABS material that is commonly used in various medical products.
[0024] The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of the retinal electrode array assembly showing the electrodes and signal conductors as well as mounting aperture for tacking the assembly inside the eye, wherein both the array and its associated electronics are located inside the eye.
[0026] FIG. 2 is a perspective view of the retinal electrode array assembly showing the electrodes and signal conductors as well as mounting aperture for tacking the assembly inside the eye, wherein the associated electronics are located outside the eye.
[0027] FIG. 3 is a perspective view of the retinal electrode array assembly wherein the array is installed inside the eye and the associated electronics are installed outside the eye at some distance from the sclera wherein the feeder cable contains both a coiled cable leading between the electronics and the sclera and a series of fixation tabs along the feeder cable for securing the feeder cable by suture.
[0028] FIG. 4 is a cross-sectional view of the retinal electrode array, the sclera, the retina and the retinal electrode array showing the electrodes in contact with the retina.
[0029] FIG. 5 depicts a cross-sectional view of the retinal electrode array showing a strain relief slot, strain relief internal tab and a mounting aperture through a reinforcing ring for a mounting tack to hold the array in position.
[0030] FIG. 6 illustrates a cross-sectional view of the retinal electrode array showing a strain relief slot and a ferromagnetic keeper to hold the array in position.
[0031] FIG. 7 illustrates a cross-sectional view of the retinal electrode array showing a strain relief slot and a mounting aperture through a reinforcing ring for a mounting tack to hold the array in position, wherein the strain relief internal tab containing the mounting aperture is thinner than the rest of the array.
[0032] FIG. 8 is a perspective view of the preferred insertion tool, for inserting the array of FIGS. 1-7 , having an curved tongs and a spring base.
[0033] FIG. 9 is a mechanical drawing of an alternate embodiment of the insertion tool illustrated in FIG. 8 having straight tongs and a.
[0034] FIG. 10 is a perspective view of an alternate embodiment using a hinged base.
[0035] FIG. 11 is a perspective view of an alternate embodiment using curved tongs and a hinged base.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
[0037] FIG. 1 provides a perspective view of a preferred embodiment of the retinal electrode array (implanted by the surgical too of the resent invention), generally designated 2 , comprising oval-shaped electrode array body 4 , a plurality of electrodes 6 made of a conductive material, such as platinum or one of its alloys, but that can be made of any conductive biocompatible material such as iridium, iridium oxide or titanium nitride, and single reference electrode 6 A made of the same material as electrode 6 , wherein the electrodes are individually attached to separate conductors 8 made of a conductive material, such as platinum or one of its alloys, but which could be made of any biocompatible conductive material, that is enveloped within an insulating sheath 10 , that is preferably silicone, that carries an electrical signal to each of the electrodes 6 . “Oval-shaped” electrode array body means that the body may approximate either a square or a rectangle shape, but where the corners are rounded. The reference electrode 6 A is not necessarily stimulated, but is attached to a conductor, as are electrodes 6 . The electrodes could be used in another application as sensors to transmit electrical signals from a nerve. The electrodes 6 transmit an electrical signal to the eye while reference electrode 6 A may be used as a ground, reference, or control voltage.
[0038] Electrode array body 4 is made of a soft material that is compatible with the body. In a preferred embodiment array body 4 is made of silicone having a hardness of about 50 or less on the Shore A scale as measured with a durometer. In an alternate embodiment the hardness is about 25 or less on the Shore A scale as measured with a durometer. It is a substantial goal to have electrode array body 4 in intimate contact with the retina of the eye.
[0039] Strain relief internal tab 12 , defined by a strain relief slot 13 that passes through the array body 4 , contains a mounting aperture 16 for fixation of the electrode array body 4 to the retina of the eye by use of a surgical tack, although alternate means of attachment such as glue or magnets may be used. Reinforcing ring 14 is colored and opaque to facilitate locating mounting aperture 16 during surgery and may be made of tougher material, such as high toughness silicone, than the body of the electrode array body to guard against tearing.
[0040] Signal conductors 8 are located in an insulated flexible feeder cable 18 carrying electrical impulses from the electronics 20 to the electrodes 6 , although the electrodes can be sensors that carry a signal back to the electronics. Signal conductors 8 can be wires, as shown, or in an alternative embodiment, a thin electrically conductive film, such as platinum, deposited by sputtering or an alternative thin film deposition method. In a preferred embodiment, the entire retinal electrode array 2 including the feeder cable 18 and electronics 6 are all implanted inside the eye. Electronics 20 may be fixated inside the eye to the sclera by sutures or staples that pass through fixation tabs 24 . The conductors are covered with silicone insulation.
[0041] Grasping handle 46 is located on the surface of electrode array body 4 to enable its placement by a surgeon using forceps or by placing a surgical tool into the hole formed by grasping handle 46 . Grasping handle 46 avoids damage to the electrode body that might be caused by the surgeon grasping the electrode body directly. Grasping handle 46 also minimizes trauma and stress-related damage to the eye during surgical implantation by providing the surgeon a convenient method of manipulating electrode array body 4 . Grasping handle 46 is made of silicone having a hardness of about 50 on the Shore A scale as measured with a durometer. A preferred embodiment of the electrode array body 4 is made of a very soft silicone having hardness of 50 or less on the Shore A scale as measured with a durometer. The reinforcing ring 14 is made of opaque silicone having a hardness of 50 on the Shore A scale as measured with a durometer.
[0042] FIG. 2 provides a perspective view of the retinal electrode array assembly 2 wherein the electrode array body 4 is implanted inside the eye and the electronics 20 are placed outside the eye with the feeder cable 18 passing through sclera 30 . In this embodiment, electronics 38 are attached by fixation tabs 24 outside the eye to sclera 30 .
[0043] FIG. 3 provides a perspective view of retinal electrode array 2 wherein electrode array body 4 is implanted on the retina inside the eye and electronics 38 are placed outside the eye some distance from sclera 30 wherein feeder cable 18 contains sheathed conductors 10 as silicone-filled coiled cable 22 for stress relief and flexibility between electronics 38 and electrode array body 4 . Feeder cable 18 passes through sclera 30 and contains a series of fixation tabs 24 outside the eye and along feeder cable 18 for fixating cable 18 to sclera 30 or elsewhere on the recipient subject.
[0044] FIG. 4 provides a cross-sectional view of electrode array body 4 in intimate contact with retina 32 . The surface of electrode array body 4 in contact with retina 32 is a curved surface 28 substantially conforming to the spherical curvature of retina 32 to minimize stress concentrations therein. Further, the decreasing radius of spherical curvature of electrode array body 4 near its edge forms edge relief 36 that causes the edges of array body 4 to lift off the surface of retina 32 eliminating stress concentrations. The edge of electrode array body 4 has a rounded edge 34 eliminating stress and cutting of retina 32 . The axis of feeder cable 18 is at right angles to the plane of this cross-sectional view. Feeder cable 18 is covered with silicone.
[0045] FIG. 5 provides a cross-sectional view of electrode array body 4 showing spherically curved surface 28 , strain relief slot 13 and mounting aperture 16 through which a tack passes to hold array body 4 in intimate contact with the eye. Mounting aperture 16 is located in the center of reinforcing ring 14 that is opaque and colored differently from the remainder of array body 4 , making mounting aperture 16 visible to the surgeon. Reinforcing ring 14 is made of a strong material such as tough silicone, which also resists tearing during and after surgery. Strain relief slot 13 forms strain relief internal tab 12 in which reinforcing ring 14 is located. Stresses that would otherwise arise in the eye from tacking array body 4 to the eye through mounting aperture 16 are relieved by virtue of the tack being located on strain relief internal tab 12 .
[0046] FIG. 6 provides a cross-sectional view of a preferred embodiment of electrode array body 4 showing ferromagnetic keeper 40 that holds electrode array body 4 in position against the retina by virtue of an attractive force between keeper 40 and a magnet located on and attached to the eye.
[0047] FIG. 7 is a cross-sectional view of the electrode array body 4 wherein internal tab 12 is thinner than the rest of electrode array body 4 , making this section more flexible and less likely to transmit attachment induced stresses to the retina. This embodiment allows greater pressure between array body 4 and the retina at the point of attachment, and a lesser pressure at other locations on array body 4 , thus reducing stress concentrations and irritation and damage to the retina.
[0048] FIG. 8 is a perspective view of the preferred insertion tool 50 . The electrode array body 4 and feeder cable 18 are extremely delicate. They must pass through a hole in the scull, pass under the four-rectus muscles of the eye, through the sclera and be attached to the retina. The insertion tool 50 has a rounded point 52 for gently separating muscle and flesh as the tool is passed through. The rounded point 52 is rigidly attached to a base 54 and top 56 . Both the base 54 and the top 58 are rounded on the outside and square on the inside. The rounding helps the tool pass through flesh without causing damage. The electrode body 4 is place between the base 54 and top 58 . Spring force traps the electrode array body 4 between the base 54 and top 58 . The tool further includes a radius 64 between the base 54 and the top 58 , which provides a space between the base 54 and the top 58 such that even pressure is applied along the length of the base 54 and the top 58 . The radius 64 reduces stress concentrations that could crack the tool at the junction of the base and top with the base and top are deflected while loading or unloading the electrode array. The even pressure allows a surgeon to hold the electrode array body 4 and feeder cable 18 firmly without causing unnecessary stress on the electrode array body 4 . The tool is fashioned from an inert biocompatible material that includes resilient elastic properties such ABS, stainless steel or titanium. ABS is suitable as a single use, disposable surgical tool while stainless steel or titanium could be steam sterilized and reused.
[0049] Once the electrode array body 4 and the feeder cable 18 are safely held in the surgical tool 50 , the surgeon can pass the tool 50 , electrode array body 4 and the feeder cable 18 in the same manner as a needle and thread. The preferred surgical tool 50 is curved to promote easy movement around the eye. The curvature of the tool generally conforms to the curvature of the outside of the sclera. Alternatively the surgical tool may be strait as shown in FIG. 9 .
[0050] FIG. 9 shows an alternate embodiment of the surgical tool 150 . The alternate surgical tool 150 has a strait base 54 and top 58 , while retaining the radius 164 and rounded point 152 of the preferred embodiment. There are advantages to strait and curved surgical tools for much the same reasons there are advantages to strait and curved needles. Different surgeons may prefer different tools.
[0051] FIG. 10 shows another alternate embodiment. Rather than relying on spring force to hold the electrode array body 4 and the feeder cable 18 in the tool 250 . The base 254 is rigidly attached to the rounded point 252 , but the top 258 is attached by a hinge 256 to the base 254 and rounded point 252 . This allows the surgeon more control of the force applied to the electrode array body 4 and the feeder cable 18 . The hinge 256 further provides for easier loading and unloading of the electrode array. This embodiment retains the radius 264 to provide even pressure along the lengths of the base 254 and the top 258 . This embodiment further includes notches 260 in the base 254 , which mate with guides 262 in the top 258 to hold the electrode array body 4 and the feeder cable 18 in the tool 250 , by holding the top 258 and base 254 together. The radius 264 reduces stress concentrations that could crack the tool at the junction of the base and top with the base and top are deflected while loading or unloading the electrode array.
[0052] FIG. 11 shows another alternate embodiment, similar to that shown in FIG. 12 . The base 354 is rigidly attached to the rounded point 352 , but the top 358 is attached by a hinge 356 to the base 354 and rounded point 352 . The hinge 356 further provides for easier loading and unloading of the electrode array. This embodiment retains the radius 264 to provide even pressure along the lengths of the base 354 and the top 358 . However, the base 354 and top 358 are curved to allow for easier insertion of the tool. This embodiment further includes a keeper 360 attached to the base 354 , which covers the top 358 to limit movement and prevents opening the tool and possibly dropping the array body 4 .
[0053] While the invention has been described by means of specific embodiments and applications thereof, it is understood that numerous modifications and variations could be made thereto by those skilled in the art without departing from the spirit and scope of the invention. | The present invention is a surgical tool for implanting an electrode array and its connected cable within an orbital socket. The insertion tool is used to aid the surgeon in pulling the electrode wire and array through the scull, four-rectus muscles of the eye, and the sclera. The insertion tool consists of a medical grade ABS material that is commonly used in various medical products. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an augmented reality system with mobile and interactive functions for multiple users that can, for example, be applied to virtual prototype evaluations for vehicles.
[0003] 2. Description of the Related Art
[0004] Augmented reality is a new virtual reality technology that combines environmental images with computer virtual images.
[0005] An augmented reality kit (ARtoolKit) can provide users with one of the most natural of browsing methods; a virtual model will move or rotate with the viewing direction of the user, which provides a more vivid experience than browsing simply with a mouse or keyboard. However, the augmented reality kit requires huge computing capabilities, which are not offered by typical mobile computing devices, such as PDAs; any computer capable of providing this huge computing ability will inevitably have a large volume and little mobility.
[0006] Moreover, how to reach a discussion from different locations or even let one user can see other user's vision.
[0007] Therefore, it is desirable to provide an augmented reality system with mobile and interactive functions for multiple users to mitigate and/or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
[0008] A main objective of the present invention is to provide an augmented reality system with mobile and interactive functions for multiple users that can, for example, be applied to virtual prototype evaluations for vehicles. So multiple users can have real-time discussion at different locations, and even see other user's vision. These discussions can be performed by PDA so the users can also input comment for record.
[0009] In order to achieve the above-mention objective, the augmented reality system with mobile and interactive functions for multiple users includes two major portions: a computer system for handling augmented reality functions, and a user system for each user. The computer system for handling augmented reality functions has very powerful functionality for processing digital image data and transforming the digital image data into a three-dimensional virtual image for each user system.
[0010] The user system includes the head-mounted display, a camera and a microphone on the display, and a portable computer. The user utilizes the head-mounted display to watch the three-dimensional virtual image and the microphone or the portable computer to communicate with other user. The camera can obtain the viewing position of the user. When the user wants to see other user's vision, the augmented reality computer system can compute the other three-dimensional virtual image watched by other user by obtaining other user's position.
[0011] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a system structure drawing of the present invention which shows the performance environment in a single area.
[0013] FIG. 2 is a system structure drawing of the present invention which shows the performance environment in two different areas.
[0014] FIG. 3 is a structure drawing of a software program related to the present invention.
[0015] FIG. 4 is a flow chart for displaying virtual images according to the present invention.
[0016] FIG. 5 is a flow chart of showing a usage status for multiple users.
[0017] FIG. 6 is a drawing of an embodiment of a portable computer according to the present invention.
[0018] FIG. 7 is a schematic drawing of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Please refer to FIG. 1 . FIG. 1 is a system structure drawing of the present invention which is used for designing the appearance of vehicles.
[0020] The present invention provides an augmented reality system with mobile and interactive functions for multiple users 10 , which includes two major portions: an augmented reality computer system 20 , and multiple user systems 50 for each user. In this embodiment, there are two users 80 a , 80 b using the augmented reality computer system at the same time.
[0021] In this embodiment, the augmented reality computer system 20 comprises a first augmented reality computer subsystem 20 a and a second augmented reality computer subsystem 20 b , wherein each subsystem 20 a , 20 b are basically electrically connected together. With reference also to FIG. 3 , each subsystem 20 a , 20 b utilizes one computer, and each subsystem 20 a , 20 b comprises an augmented reality system application program 21 . In the present invention, the augmented reality system application program 21 comprises computer image generation program code 22 , data transmission program code 23 , viewing point position analysis program code 24 and three-dimensional computer drawing data 25 . In this embodiment, the three-dimensional computer drawing data 25 is related to the vehicle appearance design drawing data.
[0022] The user system 50 comprises user systems 50 a , 50 b for each user 80 a , 80 b . The user system 50 a comprises a head-mounted display 30 a (which usually includes a speaker), a camera 3 la and a microphone 32 a mounted on the head-mounted display 30 a , and a portable computer 40 a . Similarly, the user system 50 b also comprises a head-mounted display 30 b , a camera 31 b , a microphone 32 b and a portable computer 40 b.
[0023] In this embodiment, each user 80 a , 80 b wears the head-mounted display 30 a , 30 b , and when the user 80 a , 80 b moves, his or her current position or the angle of his or her head changes, as does a virtual image 60 displayed a real image. There is a position reference object 70 in this embodiment; when the user 80 a , 80 b moves around the position reference object 70 , the virtual image 60 displayed an image would be seen at the position of the position reference object 70 , as shown in FIG. 7 .
[0024] The embodiment of FIG. 1 is substantially a performance environment in a single area. Please refer to FIG. 2 . FIG. 2 is a system structure drawing of the present invention which shows a performance environment in two different areas. The subsystems 20 a , 20 b are electrically connected together via the Internet 90 (or via an intranet for shorter distances). Since the users 80 a , 80 b are located at different positions, there are two different reference objects 70 a , 70 b , and the virtual images 60 a , 60 b are separately shown at the position of the reference objects 70 a , 70 b.
[0025] Please refer to FIG. 4 . FIG. 4 is a flow chart for displaying virtual image according to the present invention. The following description is performed at the user 80 a end:
[0000] Step 401 :
[0026] The augmented reality computer subsystem 20 a obtains the three-dimensional computer drawing data 25 .
[0000] Step 402 :
[0027] The image of the position reference object 70 is obtained; the camera 31 a is placed on the head-mounted display 30 a , so when the user 80 a faces the position reference object 70 , the camera 3 la can obtain an image of the position reference object 70 and send the image to the subsystem 20 a.
[0000] Step 403 :
[0028] The image of the position reference object 70 is analyzed to obtain a viewing point position parameter.
[0029] The viewing point position analyze program code 24 of the subsystem 20 a analyzes the image of position reference object 70 to obtain the position of the viewing point of the user 80 a . The position reference object 70 has a reference mark 71 (such as “MARKER”), and by analyzing the size, shape and direction of the reference mark, the position of the viewing point of the user 80 a can be obtained, which is indicated by a viewing point position parameter (such as a coordinate or a vector, etc.). However, this is a well-known technology, and so requires no further description.
[0000] Step 404 :
[0030] The three-dimensional virtual image 60 is calculated according to the viewing point position parameter; with the viewing point position parameter, the computer image generation program code 22 can transform the three-dimensional computer drawing data 25 into a three-dimensional virtual image 60 . This process is a well known imaging procedure
[0000] Step 405 :
[0031] The virtual image 60 is sent to the head-mounted display 30 or the portable computer 40 , so that the user 80 a can see the virtual image 60 . Please refer to FIG. 5 . FIG. 5 is a flow chart of showing a usage status for multiple users. The following description considers when the user 80 a wants to send his or her comments to the user 80 b , or the user 80 b wants to send his or her comments to the user 80 a.
[0000] Step A 1 : Recording the Comment.
[0032] In the present invention, the user 80 a can record his or her comments about the virtual image 60 in the portable computer 40 a ; for example, comments about the shape or color of the vehicle, or the inputting of instructions via the portable computer 40 a to control the subsystem 20 a to change the shape or color of the vehicle. Please refer to FIG. 6 . The portable computer 40 is a PDA; a screen 41 of the portable computer 40 displays a virtual image window 42 and a comment window 43 .
[0000] Step A 2 : Sending the Comment.
[0033] The user 80 a sends a virtual image window 42 and a comment window 43 to the subsystem 20 b via the subsystem 20 a by controlling the portable computer 40 a.
[0000] Step B 1 : Receiving the Comment.
[0034] The subsystem 20 b receives the virtual image window 42 and the comment window 43 sent from the subsystem 20 a and sends the virtual image window 42 and the comment window 43 to the portable computer 40 b .
[0000] Step B 2 : Executing an Image Switch Instruction.
[0035] If the user 80 b wants to have a direct discussion with the user 80 a , it is preferably to involve a discussion of the virtual image 60 a as seen by the user 80 a . The user 80 b can use the portable computer 40 b to execute the image switch instruction.
[0000] Step B 3 : Sending an Image Switch Execution Instruction.
[0036] The subsystem 20 b sends an image switch execution instruction to the subsystem 20 a.
[0000] Step A 3 : the Subsystem 20 a Receives the Image Switch Execution Instruction.
[0000] Step A 4 : the subsystem 20 a continuously sends the first viewing point position parameter, which is the viewing point of the user 80 a.
[0000] Step B 4 : the subsystem 20 b receives the first viewing point position parameter.
[0000] Step B 5 : The three-dimensional virtual image as seen by the first user is calculated.
[0037] Meanwhile, the subsystem 20 b calculates the virtual image 60 a according to the first viewing point position parameter.
[0000] Step B 6 : The virtual image 60 a is sent to the head-mounted display 30 b and the portable computer 40 b.
[0038] The user 80 b can thus see on the head-mounted display 30 b the image seen by the user 80 a . Since the first viewing point position parameter is a small sized piece of data, so it can be sent quickly.
[0039] Of course, while the user 80 a changes his or her viewing position, step A 4 will continuously be performed, as do steps B 4 -B 6 .
[0040] Furthermore, the users 80 a , 80 b can communicate via audio, particularly when the users 80 a , 80 b are at different positions (as shown in FIG. 2 ). For example, there are microphones 32 a , 32 b mounted in the head-mounted displays 30 a , 30 b , and the head-mounted displays 30 a , 30 b also have built-in speakers for real-time communications. Therefore, there may be no comments, and consequently no steps A 1 , A 2 , B 1 . Of course, the portable computers 40 a , 40 b may also have built-in microphones and speakers (not shown), in which case no microphones 32 a , 32 b and speakers need to be mounted in the head-mounted display 30 a , 30 b.
[0041] Data transmissions between the two subsystems 20 a , 20 b or between the subsystems 20 a , 20 b and the portable computer 40 a , 40 b can be performed by the data transmission program code 23 .
[0042] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. For example. The augmented reality computer system 20 shown in FIG. 1 can be one super computer, and so there would be no need for other subsystems, or the three-dimensional computer drawing data 25 can be stored in another computer for sharing with the two computers. | An augmented reality system with mobile and interactive functions for multiple users includes two major portions: a computer system for handling augmented reality functions, and a user system for each user. The computer system for handling augmented reality functions has very powerful functionality for processing digital image data and transforming the digital image data into a three-dimensional virtual image for each user system. The user system mainly includes a Head-Mounted Display (HMD), a microphone and a PDA. A user can see the virtual image from the HMD and use the microphone or the PDA for communication with other users. | 6 |
FIELD OF THE INVENTION
The present invention relates to the field of exercise equipment. More particularly, the present disclosure describes a system for attaching weights to a person during exercise while leaving the user's hands free.
BACKGROUND AND SUMMARY OF THE INVENTION
Use of additional weights attached to a moving body part during exercise can be beneficial to a user by increasing the work required to do a task. Many weight attaching systems thus have been developed. One type of popular system is to provide weights on user's hands and/or arms.
Conventional hand-held weights, such as dumbbells, can be used. However, this occupies the hands of a user and prevents the user from holding other things. Hand-held weights can also cause the user's hand to tire.
Various "hands-free" weights for hands and arms have been developed to substitute hand-held weights for some exercise activities. One prior-art system includes wrist weights that are attached to a person's wrists by using wrist bands. However, such wrist weights, including adjustable wrist weights, can have a tendency to slip and move about on the arms. This can cause chafing and discomfort to a user.
It is therefore one object of the present invention to comfortably and securely attach weights to a user's hands and wrists without slippage during exercise while keeping the user's thumbs and fingers free.
It is another object of the present invention to provide a "one-size-fits-all" system in which the weight attachment is adjustable for various hand sizes and for comfort.
Another issue is the determination of the proper amount of weights to use for a user. One unique feature of the preferred embodiment of the present invention is implementation of adjustable weights so that a user can vary the amounts of attached weights according to one's physical condition and/or exercise needs.
One preferred embodiment of the hands-free weights includes a flexible base, at least one weight compartment disposed in an appropriate position in the base to hold weights, a thumb attachment to anchor the base to the thumb, a palm attachment for fastening the base to the palm, and a wrist attachment for further securing the base to the wrist. The weight compartment preferably locates either on the back of the user's hand or the user's wrist if the weights are worn properly. Alternatively, the preferred embodiment can have two weight compartments with one located on the wrist area and one on the back of the hand.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages of the present invention will become more apparent in the light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings, in which:
FIG. 1 shows the first preferred embodiment of the hands-free weight system with a hand weight compartment (left hand only).
FIGS. 2a-2f illustrate how the hands-free weight system be worn.
FIGS. 3a-3c show variations of the first preferred embodiment of FIG. 1.
FIG. 4 shows the second preferred embodiment of the hands-free weight system with a wrist weight compartment (left hand only).
FIG. 5a shows the third preferred embodiment hands-free weight system with both the wrist weight compartment and the hand weight compartment (left hand only).
FIG. 5b shows a variation of the third preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the first preferred embodiment of the hands-free weight system 100 for the left hand. A right-handed system is substantially similar. A flexible supporting portion 102 has an inner surface and an outer surface. The inner surface is against the hand of a user when the hands-free weight system is worn in its intended manner. FIG. 1 shows only the outer surface. The supporting portion 102 has a hand portion 110 to fit mainly on the back of a user's hand and a wrist portion 120 to wrap around the wrist. Many flexible materials can be used for the supporting portion 102 including neoprene, leather, and nylon.
A thumb attachment 111 in the hand portion 110 is formed from a thumb hole 112 having inner surfaces through which the thumb protrudes. Alternatively, the thumb attachment 111 can be formed by a flexible thumb strap attached to the hand portion with a fastening mechanism. Thus, the thumb strap can be wrapped around the thumb and fastened. A flexible strap 115 and a "D"-shaped ring 113, both fixed to the hand portion 110 relative to each other, form a palm attachment. The D-ring 113 is attached to the hand portion 110 with a D-ring grommet 114. The outer surface of the strap 115 has a VELCRO-type loop and a VELCRO-type hook 116 at the end so that the strap 115 can be wrapped around the palm and fastened to the D-ring 113, thereby securing the hand portion 110 to the back of the user's hand. The tightness of the strap 115 can be varied at a user's will by adjusting the attachment position of the VELCRO-type hook 116 on the strap 115.
The wrist portion 120 includes two straps 122 and 124, both with a VELCRO-type hook 123 at the end of the inner surface side. Two VELCRO loop pieces 125 are attached to outer surface of the wrist porion 120 so that the two straps 122 and 124 can be wrapped around the wrist and fastened. This forms an adjustable wrist attachment with a range determined by the dimension of the hook/loop pieces.
A weight compartment 130 is disposed in the hand portion 110 in the first preferred embodiment 100. The weight compartment is configured to allow weight therein to evenly distribute, thus resulting in a balanced feel and comfort for the user. The amount of weight in the compartment 130 can be varied according to the user's needs. A number of approaches can be used to implement the adjustment of the attached weight. For example, a plurality of sets of weight patches with different weights can be used for this purpose.
FIGS. 2a-2f show how the hands-free weight system 100 is worn in its intended manner. The thumb attachment 111 anchors the device 100 relative to the thumb so that movements on the hand and arm are restricted. In particular, fingers and the thumb are free for holding other things for the convenience of the user (e.g., a water bottle). The wrist portion 120 also provides support to the wrist for comfort and safety protection during exercise.
Many variations on the first preferred embodiment 100 can be made. FIG. 3a shows that the two straps 122 and 124 of FIG. 1 in the wrist portion 120 for wrist attachment can be combined as one piece 302 with VELCRO hook/loop fasteners. The two straps 122 and 124 of FIG. 1 in the wrist portion 120 for wrist attachment can also be made on different sides of the wrist portion 120 as illustrated in FIG. 3b. The strap 115 for palm attachment in the hand portion 110 can also be directly attached to the thumb attachment 111 as shown in FIG. 3c.
The inventor recognized that the adjustable fastening mechanism for both palm attachment and wrist attachment can be implemented with a variety of fastening means, including but not limited to, a strap in conjunction with hook/loop fasteners, buckles, D-rings, or a combination thereof.
FIG. 4 shows a second preferred embodiment wherein a weight compartment 410 is located in the wrist portion 120. The amount of weights in the compartment 410 is adjustable to fit the user's needs.
FIG. 5a shows a third preferred embodiment wherein two weight compartments are implemented, a hand weight compartment 130 located in the hand portion 110 and a wrist weight compartment 410 located in the wrist portion 120. FIG. 5b further shows the palm attachment and the wrist attachment are implemented directly with hook/loop fasteners. The surfaces of the weight compartments have loop materials upon which the straps with hooks are attached.
In addition, the thumb attachment in the hand portion of the above embodiments can be replaced with one or more finger attachments instead. A finger attachment can be made in a similar manner as the thumb attachment, e.g., either using a finger hole for anchoring or a finger strap with a fastening mechanism. The finger can be any of the four fingers, i.e., the index finger, the middle finger, the ring finger and the "pinky" finger. Alternatively, both a thumb attachment and one or more finger attachments can be made in the hand portion and operate in combination.
Although the present invention has been described in detail with reference to the preferred embodiments, one ordinarily skilled in the art to which this invention pertains will appreciate that various modifications and enhancements may be made without departing from the spirit and scope of the following claims. | A device for attaching weights to a user's hands and/or wrists during exercise without occupying the user's fingers and thumbs. A thumb anchoring element, an adjustable palm attachment, and an adjustable wrist attachment are implemented to securely attach the device to a user. The device has a handweight compartment or/and a wristweight compartment to accommodate adjustable weights to the user's liking. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Applications No. 61/045,540 filed Apr. 16, 2008 and Chinese Patent Application No. 200810038143.6 filed May 28, 2008, and both of which are herein incorporated by reference for all purposes.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] The present application is directed to a system and method for generating a balanced LED light source, such as white light source. More specifically, embodiments of the present invention provide a high-brightness and white-balanced light source using individual red, green, and blue (RGB) LED emitters. For example, the LED light sources according to the present invention can be used for a variety of applications such as laboratory test equipment lighting, project display lighting, and others. In various embodiments of the present invention, LED light sources have been processed by optical components. In a specific embodiment, an LED light is formed by combining two or more color LEDs, and can be operated in continuous, pulsed, and/or modulated mode. There are other applications and implementations as well, as explained below.
[0005] Since the days of Thomas Edison, electrically powered lighting system has been an important application in daily life. The idea of incandescent light is still used today. For example, halogen lights is a type of popular incandescent lights used today. Another type of popular lighting method involves arc lamp in which light is produced by an electric arc.
[0006] While both halogen lamps and arc lamps are used for conventional lightings, they are often inadequate for specific applications. For example, arc lamps or incandescent halogen lamps are not among the best choice for illuminating samples in laboratory testing. Both arc lamp and halogen lamp cannot be quickly turned on and off, due to significant warm-up and cool-down periods. In addition, these types of lamp often post the risk of electrode damage in some cases. Moreover, these conventional lamps have relatively short life times.
[0007] Lasers are another type of light source that can be used. However, laser light sources usually provide narrow and collimated beams and laser light often has speckling artifacts which are not suitable for certain applications. Additionally, laser light sources are relatively expensive.
[0008] In contrast to arc lamps and incandescent halogen lamps, light emitting diode (LED) lights can be turned on and off in a very short time. With advent of this technological breakthrough, the potential brightness level of LED is increasing every day. The efficiency of LED light can be similar to traditional light sources, but often more efficient.
[0009] The advantages of using LED as light source include, but are not limited, (1) no IR or UV from LED lights (due to its narrow bandwidth); (2) no moving parts in the system, (3) instant On/Off, (4) small size, (5) low weight, (6) long Life (over 20,000 hours), (7) low voltage, (8) no mercury, and (9) unlikely to cause explosions. Therefore, the design and adaptation of LED illumination systems can be much simpler and less expensive but offer advanced performance with more functions.
[0010] For a LED light to be useful in certain applications, such as lighting samples in a laboratory, the LED light needs to emit light that has proper white-balance. For example, a sample might not be viewed correctly if the LED light casts an artificial color onto the sample. Thus, various conventional techniques have been proposed, but they are often inadequate. In many precision instruments where light output or brightness (Lumens) within limited area and working angle (collectively called Etendue) is required, the requirement on extracting and collimating as well as equalizing light from the LED emitters becomes extremely critical.
[0011] Therefore, an improved system and method for generating white balanced LED light source is desired.
BRIEF SUMMARY OF THE INVENTION
[0012] The present application is directed to a system and method for a generating white balanced LED light source. More specifically, embodiments of the present invention provide high-brightness and white-balanced light source using R, G, and B LED lights. For example, the LED light sources according to the present invention can be used for a variety of applications, such as laboratory test equipment lighting, projection display lighting, and others. In various embodiments of the present invention, LED light sources have been processed by optical components. In a specific embodiment, an LED light is formed by combining two or more color LEDs, and can be operated in continuous, pulsed, and/or modulated modes. There are other applications and implementations as well, as explained below.
[0013] According to the embodiments, the present invention provides a lighting system where red and blue LED lights are combined first using a first prism, and the combined light is further combined with a green LED light using a second prism, and a white light is then produced from the second prism.
[0014] In an embodiment, the present invention provides a system that includes an LED red-blue light channel, a LED green light channel, and a dichroic plate. The LED red-blue light channel contains a prism rod, dichroic prism, and relay lens. The LED green light channel contains a prism rod and relay lens and the red, blue and green lights projected through the two channels are combined into white light by the dichroic plate.
[0015] According to an embodiment, the present invention provides a an LED light system for emitting substantially white light. The system includes a first dichroic element, the first dichroic element comprises a first dichroic surface having a first coating, the first coating being adapted to reflect over 95% of a first color and transmit over 95% of a second color, the first dichroic surface having a first side and a second side. The system also includes a second dichroic element, the second dichroic element comprises a second dichroic surface having a second coating, the second coating being adapted to reflect over 95% of a third color and transmit 95% of a fourth color, the second dichroic surface having a third side and a fourth side. The system further includes a first light channel, the first light channel including a first LED light source and a first light guide, the first LED light source being characterized by the first color, the first light guide being configured to project a first light from the first LED light source onto the first side at approximately 45 degrees angle. Additionally, the system includes a second light channel, the second light channel including a second LED light source and a second light guide, the second LED light source being characterized by the second color, the second light channel being substantially perpendicular to the first light channel, the second light guide being configured to project a second light from the second LED light source onto the second side at approximately 45 degrees angle. The system includes a third light channel, the third light channel including a third LED light source and a third light guide, the third LED light source being characterized by the third color. The system includes a first relay optical element, the first relay optical element being adapted to transmit a combined light from the first dichroic element onto a predetermined location of the third side at approximately 45 degrees angle, the combined light being characterized by the fourth color, the combined light comprises a the first light reflected by the first side and the second light transmitted through the second side. Also, the system includes a second relay optical element for transmitting a light from the third light channel onto the fourth side at approximately 45 degrees angle.
[0016] According to yet another embodiment, the present invention provides an LED light system for emitting substantially white light. The system includes a first dichroic element, the first dichroic element comprises a first dichroic surface having a first coating, the first coating being adapted to reflect a first color and transmit of a second color, the first dichroic surface having a first side and a second side. The system includes a second dichroic element, the second dichroic element comprises a second dichroic surface having a second coating, the second coating being adapted to reflect a third color and transmit a fourth color, the second dichroic surface having a third side and a fourth side. The system also includes a first light channel, the first light channel including a first LED light source and a first light guide, the first light guide being less 0.5 mm away from the first dichroic element, the first LED light source being characterized by the first color, the first light guide being configured to project a first light from the first LED light source onto the first side at approximately 45 angle. Also, the system includes a second light channel, the second light channel including a second LED light source and a second light guide, the second LED light source being characterized by the second color, the second light channel being substantially perpendicular to the first light channel, the second light guide being configured to project a second light from the second LED light source onto the second side at approximately 45 degrees angle. Furthermore, the system includes a third light channel, the third light channel including a third LED light source and a third light guide, the third LED light source being characterized by the third color. Also, the system includes a first relay optical element, the first relay optical element being adapted to transmit a combined light from the first dichroic element onto a predetermined location of the third side at approximately 30 degrees angle, the combined light being characterized by the fourth color, the combined light comprises a the first light reflected by the first side and the second light transmitted through the second side. The system also includes a second relay optical element for transmitting a light from the third light channel onto the fourth side at approximately 30 degrees angle.
[0017] According to yet another embodiment, the present invention provides an LED light system for emitting combined light. The system includes a first LED light source, the first LED light source being adapted to emit a first light, the first light being associated with a first color. The system includes a second LED light source, the second LED light source being adapted to emit a second light, the second light being associated with a second color. The system also includes a third LED light source, the third LED light source being adapted to emit a third light, the third light being associated with a third color. Also, the system includes a first optical element, the first optical element adapted to reflect the first light. The system includes a second optical element, the second optical element includes a first dichroic surface, the first dichroic surface is adapted to transmit the reflected first light and deflect the second light. The system also includes a third optical element, the third optical element includes a second dichroic surface, the second dichroic surface is adapted to transmit a combined light and deflect the third light, the combined light being a combination of the first light and the second light.
[0018] According to yet another embodiment, the present invention provides an LED light system for emitting substantially white light. The system includes a first dichroic element, the first dichroic element comprises a first dichroic surface having a first coating, the first coating being adapted to reflect over 95% of a first wavelength and transmit over 95% of a wavelength, the first dichroic surface having a first side and a second side. The system includes a second dichroic element, the second dichroic element comprises a second dichroic surface having a second coating, the second coating being adapted to reflect over 95% of a third and transmit 95% of a fourth, the second dichroic surface having a third side and a fourth side. The system includes a first light channel, the first light channel including a first LED light source and a first light guide, the first LED light source being characterized by the first, the first light guide being configured to project a first light from the first LED light source onto the first side at approximately 45 degrees angle. The system includes a second light channel, the second light channel including a second LED light source and a second light guide, the second LED light source being characterized by the second, the second light channel being substantially perpendicular to the first light channel, the second light guide being configured to project a second light from the second LED light source onto the second side at approximately 45 degrees angle. The system includes a third light channel, the third light channel including a third LED light source and a third light guide, the third LED light source being characterized by the third The system includes a first relay optical element, the first relay optical element being adapted to transmit a combined light from the first dichroic element onto a predetermined location of the third side at approximately 45 degrees angle, the combined light being characterized by the fourth, the combined light comprises a the first light reflected by the first side and the second light transmitted through the second side. The system includes a second relay optical element for transmitting a light from the third light channel onto the fourth side at approximately 45 degrees angle.
[0019] Compared with conventional systems, the embodiments provide many advantages. Since LED red, blue and green light are all able to be projected into the beam-splitting films of dichroic prism and dichroic plate at angles of less than 45°, it is possible for a light system that is cheaper, compared to conventional techniques, by using beam-splitting film. Among other things, the use of the beam-splitting film according to embodiments of the present invention decreases the relative aperture required, thereby allowing the production of dichroic prism and dichroic plate to be easier and less costly. In addition, used together, the light guides and relay lens in various embodiments are used to effectively compress the divergence angle of light projection in LED chips and at the same time enhance both the combined color uniformity of the white light projected from dichroic plate and the light energy utilization rate. Also, red and blue lights share a group of relay lenses in certain embodiments, and they are identical to those for the green light. LED red, blue and green light is projected by dichroic plate from two directions and combined into white light, which makes the optical system simpler and more compact in structure. There are other benefits as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a diagram demonstrating the structure of a conventional triple-channel color combining system for red, green and blue LED light.
[0021] FIG. 2 is a simplified diagram demonstrating the structure of a dual-channel color combining system for red, green and blue LED light according to an embodiment of the present invention.
[0022] FIG. 3 is a simplified diagram showing a physical embodiment of a dual-channel color combining system for red, green and blue LED light according to an alternative embodiment of the present invention.
[0023] FIG. 4 is a simplified diagram demonstrating the structure of the dual-channel color combining system for red, green and blue LED light according to according to an alternative embodiment of the present invention.
[0024] FIG. 5 is a simplified diagram demonstrating the structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment of the present invention.
[0025] FIG. 6 is a simplified diagram demonstrating the structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment of the present invention.
[0026] FIG. 7 is a simplified diagram demonstrating the structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present application is directed to a system and method for LED light sources. More specifically, embodiments of the present invention provide high-brightness and white-balanced light source using individual RGB LED emitters. For example, the LED light sources according to the present invention can be used for a variety of applications, such as laboratory test equipment lighting, projection display lighting, and others. In various embodiments of the present invention, LED light sources have been processed by optical components. In a specific embodiment, an LED light is formed by combining two or more color LEDs, and can be operated in continuous, pulsed, and/or modulated mode. There are other applications and implementations as well, as explained below.
[0028] As explained above, LED light sources that provide proper white balance are desired. Typically, LED color is determined by the underlying semiconductor material used for the LED light. For example, aluminum gallium arsenide typically produces red LED, zinc selenide material produces blue light, etc. To produce white light (i.e., broad spectrum), a blue/UV diode with yellow phosphor is often used.
[0029] FIG. 1 is a simplified diagram of a conventional LED light source. The red LED light is guided by a light guide and projected through an X-Cube after passing through two lenses. For example, the X-Cube includes 4 prisms that are aligned against one another at angles of about 45 degrees. Similarly, the green LED light is guided by a light guide and projected through the X-Cube after passing through two lenses; the blue LED light is guided by a light guide and projected through the X-Cube after passing through two lenses. FIG. 1 is a diagram demonstrating the structure of conventional a triple-channel color combining system for red, green, and blue LED light. The light mixer shown in FIG. 1 includes an X-Cube that multiplexes the red, green, and blue lights. The combination of red, green, and blue lights results in a white light.
[0030] The X-Cube includes two dichroic coatings, f 1 and f 2 , that are orthogonal to each other. The filtering coating f 1 is positioned within the prism to reflect red light and allow green and blue light to pass through. The filtering coating f 2 is adapted to reflect blue light and allow red and green light to pass through. When the red, green, and blue light are projected from three separate directions to the X-Cube, they are combined into a white light by the filtering coatings f 1 and f 2 . For example, filter coatings are dichroic coatings.
[0031] The white light produced by combining red, green, and blue LED lights using the system above is suitable for many applications, especially as a light source for display systems. However, a system using red, green, and blue light sources with an X-Cube is typically expensive and difficult to manufacture. Among other things, since each of the red, green, and blue lights is respectively projected onto the filter coatings f 1 and f 2 at about 45 degrees angles, accurate alignment is required, thereby requiring a small tolerance. Typically, the 45 degrees entering angle for LED lights imposes a challenge in coating manufacturing, as the usable aperture from the filter coating is relatively small, even more so when LED light is used. For example, if the filter coatings are not properly manufactured, the angles for the entering light have narrow range and the efficiency for light transmission is low. Additionally, the X-Cubes are typically manufactured by gluing four rectangular shaped prisms together, and such manufacturing processes are expensive, which translate to higher costs of the system. Moreover, certain applications have geometry restriction so X-Cube type of system may not be suitable.
[0032] Therefore, it is to be appreciated the embodiments of the present invention provide systems in which red, green, and blue LED lights are efficiently combined, and the systems are cheaper and more efficient compared to the conventional system described above. In addition, the systems have a relatively more compact structure and are cheaper to be manufactured compared to conventional systems. The detailed description of the systems according to the present invention is provided below.
[0033] Compared with prior art, the embodiments of the invention provide many advantages:
[0034] 1. LED red, blue and green lights are all able to be projected into the beam-splitting films of dichroic prism 7 and dichroic plate 10 at angles of less than 45°, which helps to reduce difficulties in the production of beam-splitting film and increase the relative aperture thereof, which in turn makes the production of dichroic prism 7 and dichroic 10 easier and less costly.
[0035] 2. The red light prism rod 4 , blue light prism rod 5 , green light prism rod 6 , red-blue relay lens 8 and green relay lens 9 can effectively compress the divergence angle of light projection in LED chips and at the same time enhance both the combined color uniformity of the white light projected from dichroic plate 10 and transmission efficiency.
[0036] 3. LED red and blue lights share a group of relay lenses, which are identical to those for the green light. LED red, blue and green light is projected by dichroic plate 10 from two directions and combined into white light, which makes the optical system simpler and more compact in structure.
[0037] There are numerous other advantages as well, as evident and described through the description of the present invention.
[0038] FIG. 2 is a diagram demonstrating the structure of a dual-channel color combining system for red, green and blue LED light according to an embodiment of the present invention. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications.
[0039] As shown in FIG. 2 , an LED light system includes the following components:
[0040] 1. a red LED chip 1 ;
[0041] 2. blue LED chip 2 ;
[0042] 3. green LED chip 3 ;
[0043] 4. red light guide 4 ;
[0044] 5. blue light guide 5 ;
[0045] 6. green light guide 6 ;
[0046] 7. dichroic prism 7 ;
[0047] 8. red-blue relay lens 8 ;
[0048] 9. green relay lens 9 ; and
[0049] 10. dichroic plate 10 .
[0050] As shown in FIG. 2 , a LED light system according to an embodiment of the present invention operates in a dual-channel color combining configuration. The green channel includes a green light LED chip 3 , green light guide 6 , and green light relay lens 9 . Depending on the application, the green light guide 6 may be implemented using various types of apparatus, such a prism rod that is characterized by a pyramidal shape. The green light relay lens 9 may, as shown in FIG. 2 , include 2 lens elements. Depending on the applications, there can be fewer or more lens elements. For example, the green relay lens 9 is used for properly aligning the green light onto the dichroic plate 10 .
[0051] As shown in FIG. 2 , the LED light system includes red and blue channels, whose lights are combined first before projected onto the dichroic plate 10 . The red light channel contains a red light LED chip 1 , and red light guide 4 . For example, the red light guide, similar to the green light guide 6 , is comprised of a prism rod. The blue channel includes blue light LED chip 2 and blue light guide 5 (e.g., prism rod). For example, the prism rod may be made in various types of transparent material, such as glass, etc. According to an embodiment, the light guide 4 is approximately 0.1 mm from the dichroic prism 7 at the location Q 1 . It is to appreciated that a gap (e.g., air gap) between the light guide 4 and the prism 7 is need to ensure to allow light to exist from the light guide 4 and enter the prism 7 . In various embodiment, the gap between the light guide 4 and the prism 7 various from 0.0001 mm to about 0.15 mm. For example, while it is desirable to have a narrower gap, smaller gap size usually means less manufacturing tolerance and high cost.
[0052] The red light channel and blue light channel are combined by the dichroic prism 7 . In a specific embodiment, the dichroic prism 7 comprises two adhesively joined prisms at the section M shown in FIG. 2 . For example, the section M is coated with a beam-splitting film that transmits red light but reflects blue light. As a result, the transmitted red light and the reflected blue light are combined.
[0053] The combined light passes through the and red-blue relay lens 8 . Depending on the applications, the relay lens 8 may include fewer or more lens elements than that shown in FIG. 2 . For example, the relay lens 8 is used to properly align the combined blue-red light onto the dichroic plate 10 as shown in FIG. 2 .
[0054] The dichroic plate 10 is coated on one face with a beam-splitting film N that reflects red and blue light but transmits green light. Thus, the transmitted green light is combined with the reflected red-blue light, producing a white light as shown.
[0055] The red light LED chip 1 , the red light guide 4 , the dichroic prism 7 , the red-blue relay lens 8 , and dichroic plate 10 are arranged in sequence as illustrated in FIG. 2 . The optical axis of the red light LED chip 1 , red light guide 4 , dichroic prism 7 and red-blue relay lens 8 coincide with one another and at an angle of 45° to the face N of the dichroic plate 10 . For example, the red light LED chip 1 and red light guide 4 can be together viewed as the red light channel.
[0056] The blue light LED chip 2 , blue light guide 5 and dichroic prism 7 are arranged in sequence, with the optical axis of the blue light LED chip 2 , blue light guide 5 . In a specific embodiment, for example, the blue light LED chip 2 and blue light guide 5 can be viewed together as the blue light channel. The blue light channel is substantially perpendicular to the red channel. According to an embodiment, the light guide 5 is approximately 0.1 mm away from the dichroic prism 7 at the location Q 2 .
[0057] The green light LED chip 3 , green light guide 6 (e.g., implemented using a prism rod), and green relay lens 9 are aligned line in substantially a straight line, which is substantially perpendicular to the red light channel. For example, the green relay lens 9 may consist one or more lens elements to properly align green light onto the dichroic plate 10 . As shown in FIG. 2 , the green light is projected onto the point “o” of the dichroic. It is to be appreciated that the light guide 6 and the green relay lens 9 allow the green light to be aligned at the point “o” of the dichroic. As explained above, the combined blue-red light is aligned and projected on the point “o” of the dichroic. It is to be appreciated that the alignment of light onto the point “o” of the dichroic plate 10 is essential for the purpose of producing white light. In a specific embodiment, the point “o” is positioned at the center of the dichroic.
[0058] In the channel for red-blue light illumination, the red and blue light projected by red LED chip 1 and blue LED chip 2 respectively, enter the red light guide 4 and blue light guide 5 at a certain divergence angle. According to an embodiment, the divergence angle is approximately 30 degree when certain taper types of light guides are used. For example, the red light guide 4 and blue light guide 5 are able to compress the light divergence angle.
[0059] The combined red and blue light are then projected to dichroic plate 10 by dichroic prism 7 and relay lens 8 . Coming out of the dichroic prism, the combined red light and blue light share a single light channel and a single group of relay lenses 8 .
[0060] The light projected through relay lens 8 is reflected by dichroic plate 10 ; the green light emitted from green LED chip 3 in the other channel enters a green light guide 6 at a certain divergence angle. The green light guide 6 is able to compress the light divergence angle. For example, the light divergence angle is approximately 30 degree when certain taper types of light guides are used. The green light then passes through green relay lens 9 and the dichroic plate 10 . The red, blue and green light from the two channels are combined into white light by dichroic plate 10 .
[0061] The surface “M” of dichroic prism 7 is coated with a beam-splitting film that allows it to transmit red light but reflect blue light. As a result, LED red and blue light are combined when projected to dichroic plate 10 through the relay lens 8 . Face N of dichroic plate 10 is coated with beam-splitting film that allows it to reflect red and blue light but transmit green light. The reflected red and blue light and transmitted green lights are combined into white light when they are projected onto the dichroic.
[0062] FIG. 3 is a simplified diagram providing an alternative view of the dual-channel color combining system for red, green and blue LED light of FIG. 2 . This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications
[0063] FIG. 4 is a simplified diagram illustrating a structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 4 , the system includes a layer of beam-splitting film M 0 . According to an embodiment, the beam-splitting film M 0 is on a coupling section of the dichroic prism 7 , which consists of two parts that are joined and coupled together at the location of the beam-splitting film M 0 as shown. The beam-splitting film M 0 has the property of transmitting blue light and reflecting red light. In another embodiment, and position of the red light LED chip is exchanged with that of the blue light LED chip.
[0064] FIG. 5 is a simplified diagram illustrating a structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 5 , a system according to an embodiment of the present invention includes substantially similar components illustrated in FIG. 2 and described above. In various embodiment, the face “N” of dichroic plate 10 is respectively receiving green light from the green light channel from the left and the combined light resulting from the red and blue channels at approximately 60˜120 degree angles.
[0065] In a specific embodiment, the light guide 4 is approximately 0.1 mm away from the dichroic prism 7 at Q 1 . Similarly, the light guide 5 is approximately 0.1 mm away from the dichroic prism 7 at Q 2 . As explained above, if the light guide 4 is connected to the dichroic prism 7 , the light is spread out and the Etendue thereof becomes unacceptable for various applications. In various embodiment, the gap distance at Q 1 and Q 2 is about the same, thereby allowing the light to be correctly aligned.
[0066] FIG. 6 is a simplified diagram illustrating a structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. As shown in FIG. 6 , a system according to an embodiment of the present invention includes substantially similar components illustrated in FIG. 2 and described above. However, instead of the dichroic prism 7 , a dichroic plate 11 is used. For example, the dichroic plate has a coating that allows it to transmit red light and reflect a blue light.
[0067] FIG. 7 is a simplified diagram illustrating a structure of the dual-channel color combining system for red, green and blue LED light according to an alternative embodiment. This diagram is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications.
[0068] As shown in FIG. 7 , a light system includes a light guide 110 . For example, the light guide 110 can be a tapered pyramid that has a hollow light-tunnel that is characterized by a high reflection on all the interior walls which light travels along. The light guide 110 can also be a solid light-pipe to utilize the total reflection. For a solid light-pipe, the in/out end surfaces can have anti-reflection coatings in the working wavelength region. For example, the dimension of the in/out end surfaces and the length of pyramid determines the light cone angle (F#) and the Etendue so that the dimension of in-surface and out-surface of light guide 110 are different. Depending on the application, the shape of the light guide can be square, rectangular, elliptical, octagonal, and/or round. Within the light guide 110 , there can be other optical parts in order to improve the utilization of LED light.
[0069] A red LED source is placed within the light guide 110 , positioned close to the in-end surface.
[0070] Similarly, light guides 220 and 260 function like the light guide 110 to respectively collect and couple light from LED sources 230 and 270 .
[0071] Light from the LED 100 is collected and coupled onto the dichroic prism 140 by the light guide 110 , and lenses 120 and 130 . Similarly, light from the LED 230 is collected and coupled onto the dichroic cube 160 by the light guide 220 and lenses 210 and 200 . Light from the LED 270 is collected and coupled onto the dichroic cube 150 by light guide 260 and lenses 250 and 240 .
[0072] The prism 140 reflects light from the LED 100 . According an embodiment, only red light is reflected by the prism 140 .
[0073] The dichroic cube 150 transmits light coming out of the prism 140 (which reflects light from the LED 100 ) and reflects light from LED 270 . For example, red light coming out of the prism 140 is transmitted and the green light from the LED 270 is reflected.
[0074] The dichroic cube 160 transmits a combined light (combination of red and green light) received from the dichroic cube 150 and reflects light from the LED 230 . For example, the LED 230 is a blue LED light.
[0075] The light coming out of the dichroic cube 160 is essentially white light, which is a combination of red, green, and blue light from the LEDs. As shown in FIG. 7 , relay lenses (i.e., 120 , 130 , 250 , 240 , 210 , 200 , 170 , 180 , and 190 ) are employed to make sure that light from the LED and the dichroic cubes are projected to a desired area. For example, lights of different colors need to be aligned for color combination to take place.
[0076] It is to be appreciated that the system illustrated in FIG. 7 and described above may be modified to combine additional light. For example, to accommodate more light, an additional dichroic cube with the right dichroic property may be added (e.g., to the right of the dichroic cube 160 ), thereby combining the output from the dichroic cube 160 with an additional light source. In such manner, more than one light sources and dichroic cubes may be added.
[0077] According to embodiments, the present invention provides a lighting system where red and blue LED lights are combined first using a first prism, and the combined light is combined with a green LED light using a second prism, and a white light is produced from the second prism.
[0078] Mores specifically, the red and blue LED lights are projected to the first prism through light guides respectively for red and blue LED lights. After the red and blue lights are combined by the first prism, the combined light then passes through two relay lenses and is projected on to the second prism. The second prism combines the red-green light combination and the blue light, which is projected to the second prism first through a light guide and then two relay lenses. The resulting light from the second prism is a white light.
[0079] In a specific embodiment, red, green, and blue LED lights are combined using two prisms. The system includes a green LED source and a green LED light guide. For example, the green LED light source is part of the green LED light guide and the green LED light guide is characterized by a pyramid shape. A green light is projected from the green LED light guide onto one or more relay lenses. The system also includes red and blue light guides, and the light guides respectively include red and blue LED light sources. For the example, the red and blue light guide is characterized by a pyramid shape, which is similar to the shape of the green LED light guide. The red and blue light is combined by a first prism that is designed to combine two red and green lights. For example, the first prism includes dichroic filtering coatings. For example, the first prism includes a coating for that allows red light to pass but reflects blue light.
[0080] In an embodiment, the present invention provides a type of dual-channel color combining system for red, green and blue LED lights. The system includes a LED green light channel which contains a green light LED chip, green light guide (e.g., implemented using a prism rod), and green light relay lenses.
[0081] The system also includes an LED red and blue light channel and a dichroic. The LED red and blue light channel contains a red light LED chip, red light prism rod, blue light LED chip, blue light prism rod, a dichroic prism and red-blue relay lens.
[0082] The dichroic prism has an adhesively joined portion, which is coated with a beam-splitting film that transmits red light but reflects blue light.
[0083] The dichroic is coated on one face with a beam-splitting film that reflects red and blue light but transmits green light
[0084] The red light LED chip, red light prism rod, dichroic prism, red-blue relay lens and dichroic are arranged in a specific configuration. In this configuration, the optical axis of the red light LED chip, red light prism rod, dichroic prism and red-blue relay lens coincide with one another and at an angle of about 45° to the face of the dichroic.
[0085] The blue light LED chip, blue light prism rod and dichroic prism are arranged in sequence, with the optical axis of the blue light LED chip, blue light prism rod and dichroic prism coinciding with one another. The dichroic prism is perpendicular to those of the red light prism rod and red-blue relay lens.
[0086] The green light LED chip, green light prism rod, green relay lens and dichroic are arranged in sequence, with the optical axis of the green light LED chip, green light prism rod and green relay lens coinciding with one another and perpendicular to those of the red light prism rod, dichroic prism and red-blue relay lens. The point of intersection between the optical axis of green light LED chip, green light prism rod, green relay lens and that of the red light prism rod, dichroic prism and the red-blue relay lens is centered on the surface of the beam-splitting film of the dichroic.
[0087] The beam-splitting film on the adhesively joined section of the dichroic prism is a beam-splitting film that transmits blue light but reflects red light. The installation position of the red light LED chip can be interchanged with that of the blue light LED chip.
[0088] The face of the dichroic can be located anywhere around its own center in a counterclockwise direction by an angle of θ, wherein, 0°≦θ≦15°, the red light LED chip, red light prism rod, dichroic prism, red-blue relay lens, together with their optical axis, are rotated around the center point of the dichroic face in a counterclockwise direction by an angle doubling the value of said θ angle.
[0089] The present invention is further characterized in that said beam-splitting film on the adhesively joined section of the dichroic prism transmits blue light but reflects red light, and the installation position of the red light LED chip can be interchanged with that of the blue light LED chip; the face of the dichroic is rotated around its own center in a counterclockwise direction by an angle of θ, wherein, 0°≦θ≦15°, the blue light LED chip, blue light prism rod, dichroic prism, red-blue relay lens, together with their optical axis, are rotated around the center point of the dichroic face in a counterclockwise direction by an angle doubling the value of said θ angle.
[0090] The present invention is further characterized in that between the red light prism rod, blue prism rod and dichroic prism are a first air-gap and second air-gap respectively, with the widths of said first air-gap and the second air-gap are 0.01-0.15 mm.
[0091] The present invention is further characterized in that the dichroic prism is replaced by the first dichroic, wherein, one of the faces of the first dichroic is coated with a beam-splitting film that transmits red light but reflects blue light, and the intersection angle between the film coated face of the first dichroic and of the axis of the red light LED chip, red light prism rod, and red-blue relay lens is 45°.
[0092] In the drawings and descriptions provided above, exemplary systems are illustrated to produce white light using red, green, and blue LED light sources. However, it is to be appreciated that various embodiments of the present invention have wide range of applications. In addition to producing a white light, the embodiments of the present invention also allow users to produce other light colors. For example, by selectively turning on and/or off red, green and blue LED lights, it is possible to have red, green, or blue (or the combination or two or more lights) lights focus on the same spot while switching from one light color to another. In certain applications, lights of specific wavelength can be used to produce desired light output. For example, LED with wavelength of approximately 380 nm, 410 nm, 460 nm, 500 nm, 525 nm, 575 nm, 615 nm, 655 nm, and 705 nm cane be used as LED light source and later produce desired wavelength. In certain embodiments, invisible lights (e.g., UV, IR) are combined. It is to be appreciated that other wavelengths can be used as light source as well to produce desired output. Specific dichroic lens are used for combining light. For example, to combine lights of wavelength 380 nm and 410 nm, a dichroic lens that transmit 380 nm and reflect 410 nm wavelength is used.
[0093] Depending on the application, the LED source may be operated in continuous, pulsed, and/or modulated mode for use in various types of instruments.
[0094] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. | System and method for LED light source. According to an embodiment, the present invention provides a an LED light system for emitting substantially white light. The system includes a first dichroic element, the first dichroic element comprises a first dichroic surface having a first coating, the first coating being adapted to reflect over 95% of a first color and transmit over 95% of a second color, the first dichroic surface having a first side and a second side. The system also includes a second dichroic element, the second dichroic element comprises a second dichroic surface having a second coating, the second coating being adapted to reflect over 95% of a third color and transmit 95% of a fourth color, the second dichroic surface having a third side and a fourth side. | 5 |
FIELD OF THE INVENTION
This invention relates to an electrically conductive device and more particularly to an electrically conductive device suitable for use by workers working in the vicinity of live electrical equipment and designed to be adapted as part of a garment.
BACKGROUND OF THE INVENTION
Typically, electrical line workers, maintenance workers and construction workers working in the vicinity of live electrical equipment including transmission lines, substations, generating stations, and general construction sites where contact with live electrical equipment is common have been susceptible to electrocution as a result of malfunction or mistake which may lead to severe discomfort or even death in some circumstances.
Various articles have been used in order to avoid the potentially undesirable effects of electrical current running through one's body. Some of the more traditional articles for eliminating electrical current have included grounded wrist straps, grounded smocks, grounded footwear and gloves constructed of electrically conductive material.
Generally, the proposed articles have been for use in the field of static electricity control for use in the manufacturing of electronic components where there is a need for the workers involved to be as free as possible of static electricity due to the extremely sensitive nature of electronic components.
One of the difficulties attending the application of the above mentioned articles is their connection to ground that causes the articles insufficient for reducing the health risk to the user in the presence of harmful electric current.
SUMMARY OF THE INVENTION
The present invention provides for an electricity shunting device adapted to be used as part of a garment designed to overcome the above shortcomings.
An object of the present invention is to provide a shunting/protecting device which is simple and easy to use.
Another object of the present invention is to construct an electricity shunting garment which is manufactured in a simple manner and therefore can be constructed inexpensively and ultimately sold at a relatively low price to the consumer thereby making it widely available.
An additional object of the present invention is to provide an electricity shunting and rerouting device comprising a) a flexible conductor; b) conductive bracelets; and c) attachment means for connecting said flexible conductor to said conductive bracelets.
An additional object of the present invention is to provide an electricity shunting and rerouting garment comprising a) a flexible conductor; b) conductive bracelets; c) attachment means for connecting said flexible conductor to said conductive bracelets; and d) means for securing said combination of flexible conductor and conductive bracelets to the garment, said garment having a pair of sleeve sections connected to a body section, said sleeve sections terminating in hems at cuff sections, and a collar section; whereby the flexible conductor is adapted to run uninterrupted along the sleeve and collar sections leading to the conductive bracelets forming part of the cuff sections.
An additional object of the present invention is to provide a method for shunting and rerouting electrical energy away from a worker's inner parts comprising the steps of a) connecting a flexible conductor to conductive bracelets; and b) attaching said flexible conductor and conductive bracelets combination to a garment.
Further objects and advantages of the present invention will be apparent from the following description, wherein preferred embodiments of the invention are clearly shown.
This invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further understood from the following description with reference to the drawings in which:
FIG. 1 is a front view of a garment embodying principles of the present invention;
FIG. 2 is a front view of an electricity shunting device of the present invention;
FIG. 3 is a front view of an alternative embodiment of the present invention;
FIG. 4 is a front view of an electricity shunting device of an alternative embodiment of the present invention; and
FIG. 5 is a front view of a portion of an electricity shunting device of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The garment 10 illustrated in FIG. 1 is in the form of a work shirt having a front that can be opened and closed. This particular style of garment is employed solely for purposes of illustration, since, as will readily be understood from the following detailed description, the shape and style of the garment can vary without departing from the principles of the present invention.
The garment 10 includes a body section 11, sleeve sections 12, 13, connected to said body section 11, terminating in hems 14 and 15 at cuff sections 18 and 19 respectively and collar section 16.
An insulated flexible wire or conductor 17, which can be made of copper for instance, and of different types of element and sizes according to voltage range one may face in a working environment, runs uninterrupted within the material raceway of sleeve sections 12, 13 and collar 16. Attached to flexible wire 17 at the open ends located in cuff sections 18, 19 through attachment means 22, 23 are conductive metal bracelets 20 and 21 respectively, which may contain copper for instance, or any other conductive metal suitable to the application of the present invention. The bracelets 20 and 21, or wrist straps, are characterized by their conductive inner core and insulated outer shield which are integral to the cuff sections 18 and 19.
Referring to FIG. 3, in an alternative embodiment, anklets 31 and 32 could be used, in combination with the bracelets 20 and 21 and flexible wire 17. A waistband 40 would be connected to flexible wire 42 using attachment means 44. The flexible wire 42 would be connected to flexible wire 17 at the collar 16 of the garment 10 using attachment means 46. The waistband 40 would be characterized by its conductive inner core and insulated outer shield. The waistband 40 would be connected to flexible wire 33 using attachment means 44 as above described which would then run along the legs 34, 35 of the pants section 30 of the garment. At an ankle section 50 of the pants section 30 the flexible wire 33 would be connected to anklet 32 using attachment means 54. At an ankle section 52 of the pants section 30 the flexible wire 33 would be connected to anklet 31 using attachment means 56. Anklets 31 and 32 would be constructed in a similar manner as bracelets 21 and 22.
It is to be noted that the garment is constructed in a manner that facilitates normal cleaning without impacting its effectiveness in the minimizing of electrocution.
Furthermore, the bracelets 20 and 21 (or anklets 31 and 32 or waistband 40) and flexible wire 17 connection are at such locations as to provide minimal effect on the operations of the worker wearing the garment. The elongate, flexible and washable electrical wire/conductor 17 (or 33 and 42 in the alternative embodiment) provides no interference whatsoever with the worker, either at its exterior or interior portions (of the sleeves or legs) or adjacent the seam.
Alternatively, the bracelet/flexible wire combination, as illustrated in FIGS. 2 and 4, can easily be adapted to be temporarily removed from the garment, for washing for instance, or for use of the garment in a non-electrical context through the use of non-permanent attachment means such as hook and loop members (VELCRO™) thereby further preventing any deterioration of the shunting and rerouting device 25 per se.
A portion of the present invention is shown in FIG. 5. Any one of the bracelets 21, 20, 31, 32 or 40 is characterized by their conductive inner core 62 and insulated outer shield 60. The attachment means 22, 23, 44, 54, 56 or 46 is any electrical connection means, such as soldering or welding, as known in the art. The attachment means 22, 23, 44, 54, 56 or 46 contains conductive material, such as copper, which contacts the skin of the wearer. The insulated outer shield, such as a plastic shield, minimizes the likelihood that the present invention comes into direct contact with electrical energy. Rather, electrical energy enters the body of the user, usually through the hand or foot, and then enters the device through the conductive material in the attachment means.
In operation, the described combination garment, bracelet, flexible wire/conductor achieve, when used in combination with approved safety boots in a practical and effective way, the advantages of shunting and rerouting electrical energy away from the worker's heart and muscles in order to reduce or eliminate, depending on the conditions such as various voltage ranges, muscle contractions, diaphragmatic contractions and ventricle fibrillation in the event of contact with live electrical equipment. Safety boots isolate the wearer from the ground thereby preventing an additional path for current to flow.
This shunting and rerouting effect is achieved by allowing the electrical energy to mainly flow through the worker's hands, waist, ankles, the bracelets, the anklets, the waistband and flexible conductors instead of through the heart where an energy surge might be problematic, or even fatal, thereby giving the worker time to detect current and to remove him/herself from a potentially bad if not fatal situation.
An advantage of the present invention is to keep energy away from the heart or other vital organs. A conductor surrounding the heart may shunt electrical energy away from the inner parts of the person, such as the heart or other vital organs. By shunting, the conductor joins two or more points through which current is diverted away from the heart or other like vital organ.
Inner parts protected by the present invention are electrically sensitive organs or muscles, such as, the heart, lungs or diaphragm.
The various embodiments of the invention may be used depending on the level of voltage of the electricity that may enter the body. For example, for extra low voltage two hand bracelets and a waistband may be used. For low voltage, two hand bracelets, and either the waistband or insulated boots may be used. For high voltage, two bracelets, the waistband, two ankle bracelets and boots may be used.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | An electricity shunting and rerouting device designed as forming an integral part of a garment comprising conductive metal bracelets (and/or waistbands and/or anklets) joined by an insulated conductor, the size and type of which may vary depending on the application, thereby allowing the potentially harmful electrical current to flow through the insulated conductor/wire and rerouting the current away from the worker's inner parts, such as vital organs and muscles, thereby minimizing the health risk of electrocution. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to sizing apparatus for metal parts of relatively thin cross-section and in particular to an apparatus for accurately sizing the tube stock.
In the manufacture of products which incorporate relatively thin-walled metal tubing, it is often necessary to use tubing having certain portions sized to close tolerances of the order of 0.005 inch. Such close tolerances are required, for example, on portions of automobile tail pipes. Applications wherein one portion of a tube must be telescoped into a second tube are further examples requiring close tolerances on the interfitting tube sections.
An apparatus for sizing tube stock to close tolerances is disclosed and claimed in U.S. Pat. No. 3,049,034 which is herewith incorporated by reference. Such apparatus includes slidably mounted arbor members and die heads which respectively contact the interior surface and exterior surface of the end portion of a tube to be sized to close tolerances. In the aforementioned patent, both the arbor members and die heads are mounted to the apparatus by bolts. As such, the bolts must first be removed necessitating waste of time whenever it is desirable to remove the arbors or die heads. Disclosed herein is a quick disconnect structure and tools to facilitate removal of the arbors and die heads in a relatively quick and easy manner as compared to the previously utilized bolt structure.
SUMMARY OF THE INVENTION
One embodiment of the present invention is a tube stock sizing apparatus comprising a stationary annular member, a plurality of spaced finger members for movement toward and away from the central axis of the annular member and spring biased toward the axis, the finger members extending parallel to the annular member axis with their outer surfaces being adapted to engage the inner bore of a section of tube stock to be sized, the inner surfaces of the finger members being inclined, spring biased quick disconnect means releasably engageable with the finger members and operable to mount the finger members to the annular member, a tapered spindle extending centrally through the finger members and engaging the inclined inner surfaces thereof, the spindle being movable along the axis of the annular member to displace the finger elements outwardly therefrom and into engagement with the tube stock, a plurality of spaced die elements for movement toward and away from the central axis of the annular member and spring biased away from the axis, the inner surfaces of the die elements being adapted to engage the outer surface of a section of tube stock to be sized, the outer surfaces of the die elements being inclined, removable tool means releasably engageable with the die elements and operable to mount the die elements to the annular members, a ring member encircling the annular member and having an inclined inner surface engaging the inclined outer surfaces of the die elements, the ring member being movable along the axis of the annular member to displace the die elements inwardly toward the axis and into engagement with the tube stock, and means for moving the spindle and the ring member independently of each other, the means comprising a hydraulic cylinder centrally divided into a first and second working chamber and mounted coaxially with the stationary annular member, a piston in the first chamber having an operative connection to the spindle, a piston in the second chamber having an operative connection to the ring member.
Another embodiment of the present invention is a tube stock sizing apparatus with quick disconnect arbor and die heads comprising a stationary annular member with a central, longitudinally extending axis, a plurality of spaced arbor members mounted to the annular member and spring biased for movement toward the central axis of the annular member and having outwardly facing surfaces adapted to engage the inner bore of a section of tube stock to be sized, pin means mounted to the annular member and spring biased into the arbor members to secure the arbor members to the annular member but yieldable to allow disengagement from the annular member and unmounting of the arbor members from the annular member, a plurality of die heads mounted to the annular member and spring biased for movement away from the central axis of the annular member and having engaging surfaces adapted to engage the outer surface of a section of tube stock to be sized, removable elongated member means extending longitudinally in the direction of the axis and being releasably mounted to the die heads to hold at least a portion thereof to the annular member, a tapered spindle extending centrally through the arbor members and engaging the inwardly facing surfaces thereof, the spindle being movable along the axis of the annular member to displace the arbor members outwardly therefrom and into engagement with the tube stock, and a ring member encircling the annular member and having an inner surface engaging the die heads and being movable along the axis of the annular member to displace the die heads inwardly toward the axis and into engagement with the tube stock.
A further embodiment of the present invention is a tube stock sizing apparatus comprising a stationary annular member, a plurality of spaced finger members supported by the annular member for movement toward and away from the central axis of the annular member, the finger members extending parallel to the annular member axis with their outer surfaces being adapted to engage the inner bore of a section of tube stock to be sized, the inner surfaces of the finger members being inclined, a tapered spindle element extending centrally through the finger members and engaging the inclined inner surfaces thereof, the spindle element being movable along the axis of the annular member to displace the finger elements outwardly therefrom and into engagement with the tube stock, a plurality of spaced die elements supported by the annular member for movement toward and away from the central axis of the annular member, the die members having legs with recesses, the inner surfaces of the die elements being adapted to engage the outer surface of a section of tube stock to be sized, the outer surfaces of the die elements being inclined, elongated rods extending longitudinally in the direction of the axis and into the recesses releasably securing the die heads to the annular member, a ring member encircling the annular member and adapted to engage the inclined outer surfaces of the die elements, the ring member being movable along the axis of the annular member to displace the die elements inwardly toward the axis and into engagement with the tube stock, means for moving the spindle element and the ring member independently of each other, the means comprising a dual hydraulic cylinder, spring biased pins mounted to the annular member and normally urged into engagement with the finger members securing same thereto but yieldable to allow unmounting of the finger members from the annular member, rod means engageable with the spring biased pins to hold same away from the finger members.
It is an object of the present invention to provide a tube stock sizing apparatus including quick disconnect arbors and die heads.
A further object of the present invention is to provide a new and improved die head and arbor mounting structure.
In addition, it is an object of the present invention to provide a method and tools for quickly mounting and unmounting arbors and die heads on a tube stock sizing apparatus.
It is an object of the present invention to provide a quick disconnect structure for mounting the arbors and die heads of a tube stock sizing apparatus.
In addition, it is an object of the present invention to provide mounting means for securing an arbor and die head.
Related objects and advantages of the present invention will become apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of apparatus incorporating the present invention.
FIG. 2 is a further perspective view but taken from the opposite side of the apparatus.
FIG. 3 is an end view of the stock receiving head of the apparatus.
FIG. 4 is a sectional view taken generally along the line 4--4 of FIG. 3.
FIG. 5 is a sectional view which represents an extension of the sectional view shown in FIG. 4.
FIG. 6 is a perspective view of a tool to remove the arbor members.
FIG. 7 is a bottom view of the shank of the tool shown in FIG. 6.
FIG. 8 is an enlarged cross-sectional view taken along the line 8--8 of FIG. 4 and viewed in the direction of the arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated 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 initially to FIGS. 1 and 2, the reference numeral 10 generally designates a rectangular base or frame which houses a hydraulic fluid reservoir, not shown. Mounted on one side of the tank is an oil reservoir 11 having a flush pump motor 12 supported thereon. The motor serves to pump oil through the line 13 into the stock receiving head, generally designated at 14 and after moving through the head, the flushed oil accumulates in the receptacle 16 and runs through the tube 17 and filter screen 18 back to the oil reservoir 11. Extending from the stock receiving head 14 is a hydraulic cylinder 51. The cylinder serves to actuate certain components of the head 14 as will be explained in detail with reference to FIGS. 3-5. Extending from the cylinder are hydraulic lines 19, 21, 22 and 23. The hydraulic lines extend to a panel 24 and are connected by means of further hydraulic lines to control valves in a conventional manner.
Atop the vertically extending plate 26, there is mounted an electrical control box 27 having various push button switches thereon. Adjacent the control box there is mounted a heat exchanger 28 having an input line 29 for conducting hydraulic fluid thereto and an outlet line 31 for returning fluid to the hydraulic fluid reservoir.
As may best be seen in FIG. 2, the heat exchanger is provided with a motor driven fan 32 for moving cooling air therethrough. Mounted beside the hydraulic cylinder 51 is a motor 33 whose shaft operates hydraulic fluid pumps 34 and 36 through suitable couplings. The motor and pumps thus serve to provide hydraulic pressure for the cylinder 51.
Referring now to FIGS. 3, 4 and 5, the work accommodating head and the hydraulic actuating means therefor will be described. The actuating means includes a cylinder 51, the left-hand portion of the cylinder being shown in FIG. 4 and the right-hand portion thereof being shown in FIG. 5. The cylinder is divided centrally by a wall 52 and the wall is provided with adjacent apertures 53 and 54. The aperture 53 communicates with the cylinder bore 56 and the aperture 54 communicates with the cylinder bore 57 to permit access of hydraulic fluid thereto. Movable within the bore 56 is a piston 58 provided with suitable piston rings 59. The bore 57 accommodates a similar piston 61 provided with piston rings 62. The outer end of the cylinder, shown in FIG. 5 has rigidly secured thereto an annular member 63 and is closed by a member 64 having a central aperture therein. The member 64 is rigidly held in sealed relation to the end of the cylinder by means of screws 66 (FIG. 1), the annular seal 68 providing a fluid-tight junction.
A piston shaft 69 has a reduced end threaded into and thereby rigidly secured to the piston 61. The shaft 69 extends through the central aperture in the member 64 and is movable therein, a hydraulic seal 71 and a bronze bushing 72 being provided therefor. An aperture 73 in the member 64 communicates with the area surrounding the central section of the shaft 69 and provides access for hydraulic fluid to the rear face of the piston 61. The reduced outer end 74 of the shaft 69 is threaded to accommodate locking nuts 76 and 77 which fix the position of a plate 78 upon the shaft. The plate 78 is rectangular in configuration and is provided with apertures adjacent its corners to accommodate thrust rods 79, the rods being secured to the plate 78 by means of nuts 81. While only one of the rods 79 is shown in FIG. 5 for purposes of clarity, the general disposition of the rods will be apparent from FIG. 1. From the foregoing, it will be apparent that by controlling the hydraulic pressure on opposite sides of the piston 61, the plate 78, and consequently the thrust rods 79, may be positionally controlled.
Referring now to FIG. 4, it may be seen that the opposite end of the cylinder 51 is provided with an annular member 82 which receives machine screws similar to screws 66 of FIG. 1, the screws serving to mount and seal the member 83 upon the open end of the cylinder. The sealing member 84 is a counterpart of the seal 68 in FIG. 5. The piston 58 is rigidly attached to a reduced end of the piston shaft 86 which extends through a central aperture in the member 83 and cooperates with the hydraulic seal 87 and the bronze bushing 88. The member 83 is provided with an aperture 89 which communicates with the area adjacent the enlarged central portion of the piston shaft 86 and provides for access of hydraulic fluid to the rear face of the piston 58.
The outer end of the shaft 86 is reduced, as indicated at 91 and is provided with a tapped bore 92 and external threads 93. The externally threaded end of the shaft accommodates nuts 94 and 96 which may be adjustably positioned and locked along the reduced end 91 of the shaft. The nut 96 is adapted to engage an internal shoulder formed in a stop member 98 rigidly mounted in a central opening in a stationary plate 99. Plate 99 is provided with apertures 101 which freely accommodate the thrust rods 79. It will be evident from FIG. 4, that by controlling the hydraulic pressures on the opposite faces of the piston 58, the position of shaft 86 may be controlled. Engagement of the nut 96 with the stop member 98 serves to establish the other limit of the movement of the shaft 86, this limit being adjustable for positioning of the nut 96 on the reduced end portion of the shaft.
The head for accommdating the work or tube stock will now be described with reference to FIGS. 3 and 4. The bore 92 in the shaft 86 accommodates an externally threaded member 102 which is also threaded into an axial aperture 104 in a tapered mandrel 106. The mandrel 106 is thus rigidly attached to and movable with the shaft 86. Threaded upon the stop member 98 is a stationary annular member 107. As may best be seen in the upper portion of FIG. 4, the annular member 107 is provided with a series of equally spaced, radial apertures, each of which slidably accommodates a casing or pin 108. The inner ends of the pins are each provided with forwardly projecting fingers or arbor members 109, the members 109 being joined to the pins 108 by means of quick disconnect members 111. The stationary member 107 is provided with a radial aperture 112 adjacent each of the pins, the apertures being closed by plates 113. Compression springs 114 are disposed within the apertures 112 and at their upper ends bear against the plates 113 and, at their lower ends, bottom against members 116 which are carried by the pins 108. It will thus be evident that the arbor members 109 are biased toward the axial center line of the head by the springs 114 and are moved upwardly by engagement with the tapered mandrel 106. With a section of tube stock, indicated at 117, disposed over the arbor members, the members 109 will be urged against the inner circumference of the tube stock in proportion to the positioning of the mandrel 106. For purposes of clarity, only one of the arbor members 109 is shown in FIG. 4, although it will be understood that multiple members are carried by the member 107.
Quick disconnect members 111 have a pin shaped main body 130 with an enlarged portion 131 located intermediate the ends of the main body forming a shoulder upon which a helical spring 132 rests. The top end of spring 132 abuts against the underside of washer 133 mounted to pin 130 with the washer being urged against a pair of pins 134 fixedly secured to casing 108. Thus, spring 132 urges pin 130 downwardly until the bottom end 135 of the pin extends into hole 136 of arbor member 109 locking the arbor member to casing 108. Hole 136 is provided with a counter bore 137 aligned with hole 138 extending through casing 108. An enlarged portion of pin 130 forms shoulder 139 and is sized to be received in counter bore 137 when the pin is in the downward position. Hole 138 is enlarged above shoulder 140 to allow enlarged portion 131, helical spring 132 and washer 133 to slide freely within hole 138.
In order to remove arbor members 109, the pin is pulled to the upward position as depicted to FIG. 4. An elongated member or rod 141 is extended through holes 142 and 143 provided respectively in annular member 107 and casing 108. Elongated member 141 may be positioned immediately against and beneath shoulder 139 holding the pin in the upward position. In order to secure the arbor member 109 to casing 108, elongated member 141 is pulled outwardly allowing the helical spring to force the pin downwardly into hole 136.
Tool 150 (FIG. 6) is provided to allow the operator to pull pins 130 to the upward position. The tool (FIG. 5) includes a main body 151 with an arcuate cam surface 152 and a depending hollow cylinder 153 pivotally mounted thereto by pin 154. A handle 155 is fixedly attached to the main body and extends upwardly therefrom. The bottom end 156 of cylinder 153 includes a pair of aligned slots 157 and 158 (FIG. 7) which are sized to receive pin 159 (FIG. 4) fixedly secured to the top end of pin 130. Thus, to move pin 130 to the upward position, cylinder 153 is extended through hole 160 of annular member 126 (FIG. 4) and into hole 138 of casing 108 until pin 159 enters slots 157 and 158. Cylinder 153 may then be rotated until pin 159 enters the offset slots 161 (FIG. 6) in communication with slots 157 and 158 thereby locking pin 159 to cylinder 153. Handle 155 may then be pivoted to the left as viewed in FIG. 4 with cam surface 152 contacting the outer surface of annular member 126 thereby pulling the pin upwardly until elongated member 141 is positioned beneath shoulder 139. In order to relock the casing to the arbor member, the process is repeated and tool 150 is removed.
The stationary member 107 is further provided with an additional series of equally spaced radial apertures slidably accomodating housings 118. Each housing 118 includes a hole 171 extending therethrough and having the top end 173 of hole 171 enlarged to receive the downwardly extending projection 172 provided on arcuate die head 121. A pin 170 is fixedly mounted to projection 172 and extends freely into hole 171. A recess 174 is provided in pin 170 (FIG. 8) to receive the shank 175 of tool 176 extending freely through front ring 129 and into hold 176 being arranged perpendicular to hole 171 and extending through pin 170. The inner end 177 of shank 175 includes a pair of spring biased ball bearings 178 which engage stop surface 179 of the enlarged end of the hole 176 thereby securing the tool within the hole until the handle is grasped and pulled outwardly. Thus, when tool 176 is mounted to pin 170 and extending through recess 174, the die head 121 is locked to the pin whereas removal of the tool 176 allows for the removal or separation of the die head 121 from housing 118.
Adjacent each of the housings 118, the stationary member 107 is formed so as to accommodate compression springs 122 which bear against sidewardly extending members 123 carried by the housings 118. The housings 118 are thus urged radially outwardly from the axial center line of the assembly by the springs 122. For purposes of clarity, only one of the die heads 121 is shown in FIG. 4, although it will be understood that multiple heads are carried by the member 107.
At their outer ends the housings 118 are provided with inclined faces which are slidably engaged by the inner tapered wall 124 of an outer, annular member 126. The member 126 is provided with a bronze bearing ring or bushing 127 and receives the threaded ends of the thrust rods 79. A front ring 129 attached to the face of the stationary member 107 by means of machine screws 191 completes the assembly.
As shown in FIGS. 4 and 5, the piston 61, and consequently the annular member 126, are in their extreme rightward or retracted position, and the housings 118 are thereby disposed in their maximum inward positions and against the tube stock 117. Shifting of the position of the piston 61 leftwardly, as viewed in FIG. 5, serves to correspondingly shift the position of the member 126 to permit the die members 121 to withdraw from the outer surface of the tube stock 117. Similarly, application of hydraulic pressure to the leftward face of the piston 58 will shift the mandrel 106 from its extreme leftward position of FIG. 4. Such shifting of the mandrel permits the arbor members 109 to retreat from the inner circumference of the tube stock 117.
In one embodiment, the hydraulic system and electrical circuitry utilized to operate the tube stock sizing apparatus is conventional in nature and is described in U.S. Pat. No. 3,049,034 which is herewith incorporated by reference. Suffice it to say that controls are provided for either manually or automatically sizing tube stock by accurately controlling the movement of pistons 58 and 61. The apparatus disclosed herein is identical to that disclosed in U.S. Pat. No. 3,049,034 with the exception that the apparatus disclosed herein is provided with quick disconnect mounting means for securing the arbor members and die heads.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | A quick disconnect arbor and die head for a tube stock sizing apparatus. A plurality of arbors and die heads are slidably mounted to a tube stock sizing apparatus and are respectively urged into engagement with the inwardly facing and outwardly facing surfaces of a section of tube stock. A hydraulic piston arrangement is operable to move the arbor members and die heads to and from the tube stock. An annular member surrounds the arbor members and die heads. Spring biased pins mounted in the annular member releasably engage and secure the arbor members to the annular member. An external tool is engageable with the top end of each pin to pull the pins upwardly disengaging the arbor members. A rod extends through the annular member and contacts the pin and secures the pin in the upward disengaged position. Each die head includes a leg with a recess extending freely into a hole. A rod extends into the hole and is arranged perpendicularly to the leg and extends through the recess releasably holding the leg and die head to the annular member. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to a fuel cell formed by stacking an electrolyte electrode assembly and a metal separator in the form of a corrugated plate in a stacking direction. The electrolyte electrode assembly includes electrodes and an electrolyte interposed between the electrodes. A reactant gas flow field as a passage of a fuel gas or an oxygen-containing gas is formed on one surface of the metal separator. A reactant gas passage for the fuel gas or the oxygen-containing gas extends through the fuel cell in the stacking direction.
BACKGROUND ART
[0002] For example, a solid polymer electrolyte fuel cell employs an electrolyte membrane. The electrolyte membrane is a polymer ion exchange membrane. The electrolyte membrane is interposed between an anode and a cathode to form a membrane electrode assembly (MEA). The membrane electrode assembly is sandwiched between a pair of separators to form a unit cell for generating electricity. In use, normally, a predetermined number of unit cells are stacked together to form a fuel cell stack.
[0003] In the fuel cell, a fuel gas flow field is formed in a surface of one separator facing the anode for supplying a fuel gas to the anode, and an oxygen-containing gas flow field is formed in a surface of the other separator facing the cathode for supplying an oxygen-containing gas to the cathode. Further, a coolant flow field is formed between the separators for supplying a coolant along surfaces of the separators.
[0004] In this regard, the fuel cell may adopt internal manifold structure in which fuel gas passages for flowing a fuel gas therethrough, oxygen-containing gas passages for flowing an oxygen-containing gas therethrough, and coolant passages for flowing a coolant therethrough are formed in the fuel cell and extend through the fuel cell in the stacking direction.
[0005] As a fuel cell of this type, for example, a fuel cell disclosed in Japanese Laid-Open Patent Publication No. 2006-172924 is known. As shown in FIG. 10 , a separator 1 disclosed in Japanese Laid-Open Patent Publication No. 2006-172924 includes a fuel gas flow field 2 . The fuel gas flow field 2 includes a main flow field 3 connected to an inlet manifold 6 a and an outlet manifold 6 b through a distribution section 4 and a merge section 5 .
[0006] The main flow field 3 is divided by a plurality of ribs 7 a, and the distribution section 4 and the merge section 5 are divided by a plurality of ribs 7 b, 7 c. The ribs 7 b, 7 c are divided respectively by disconnected portions 8 a, 8 b in the middle in the longitudinal direction. The disconnected portions 8 a, 8 b of the ribs 7 b, 7 c are shifted from disconnected portions 8 a, 8 b of the adjacent ribs 7 b, 7 c in the longitudinal direction of the separator 1 .
SUMMARY OF INVENTION
[0007] However, in the separator 1 , since each of the ribs 7 b, 7 c is divided into a plurality of pieces by the disconnected portions 8 a, 8 b, water produced in the power generation reaction tends to stagnate at the disconnected portions 8 a, 8 b. In this case, the fuel gas and the oxygen-containing gas flow around the produced water, and flows between the ribs 7 b, 7 c. Therefore, the water cannot be discharged from the fuel cell. As a result, the fuel gas and the oxygen-containing gas may not flow smoothly, and thus the power generation performance may be lowered undesirably.
[0008] Further, in the case where water flows into the fuel cell stack from the outside, the water may stagnate therein, and cannot be discharged from the fuel cell stack. As a result, the power generation performance may be lowered undesirably.
[0009] Further, since the ribs 7 b, 7 c are divided into a plurality of pieces by the disconnected portions 8 a, 8 b, the sizes of the distribution section 4 and the merge section 5 that are, in effect, not used in power generation become large. As a result, the entire separator 1 is large in size.
[0010] The present invention has been made to solve the problems of these types, and an object of the present invention is to provide a fuel cell which is capable of improving the performance of discharging water produced by the power generation reaction in reactant gas flow fields, and suitably achieving size reduction of the fuel cell.
[0011] The present invention relates to a fuel cell formed by stacking an electrolyte electrode assembly and a metal separator in the form of a corrugated plate in a stacking direction. The electrolyte electrode assembly includes electrodes and an electrolyte interposed between the electrodes. A reactant gas flow field as a passage of a fuel gas or an oxygen-containing gas is formed on one surface of the metal separator. A reactant gas passage for the fuel gas or the oxygen-containing gas extends through the fuel cell in the stacking direction.
[0012] The metal separator includes a buffer provided between an end of the reactant gas flow field and the reactant gas passage. A plurality of continuous linear guide ridges are provided on the buffer, and the linear guide ridges include bent portions, and have different lengths in a stepwise manner.
[0013] In the present invention, the continuous linear guide ridges are provided in the buffer. The linear guide ridges include the bent portions, and have different lengths in a stepwise manner. Thus, the reactant gas does not flow around water produced in the power generation reaction. In the structure, by the reactant gas, the water produced in the power generation reaction is easily and reliably discharged. Also, the reactant gas can be supplied uniformly, and a desired power generation performance can be maintained suitably. Further, the areas of the buffer can be reduced effectively, and the overall size of the fuel cell can be reduced easily.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is an exploded perspective view showing main components of a fuel cell according to a first embodiment of the present invention;
[0015] FIG. 2 is a view showing one surface of a cathode-side metal separator of the fuel cell;
[0016] FIG. 3 is an enlarged view showing main components of the cathode-side metal separator;
[0017] FIG. 4 is a view showing the other surface of the cathode-side metal separator;
[0018] FIG. 5 is a partial perspective view showing an inlet buffer of the cathode-side metal separator;
[0019] FIG. 6 is a cross sectional view showing the cathode-side metal separator, taken along a line VI-VI in FIG. 5 ;
[0020] FIG. 7 is a front view showing an anode-side metal separator of the fuel cell;
[0021] FIG. 8 is an exploded perspective view showing main components of a fuel cell according to a second embodiment of the present invention;
[0022] FIG. 9 is a front view showing an intermediate metal separator of the fuel cell; and
[0023] FIG. 10 is a view showing a separator disclosed in Japanese Laid-Open Patent Publication No. 2006-172924.
DESCRIPTION OF EMBODIMENTS
[0024] As shown in FIG. 1 , a fuel cell 10 according to a first embodiment of the present invention includes a cathode-side metal separator 12 , a membrane electrode assembly (electrolyte electrode assembly) (MEA) 14 , and an anode-side metal separator 16 .
[0025] For example, the cathode-side metal separator 12 and the anode-side metal separator 16 are made of steel plates, stainless steel plates, aluminum plates, plated steel sheets, or metal plates having anti-corrosive surfaces by surface treatment. The cathode-side metal separator 12 and the anode-side metal separator 16 are formed by pressing metal thin plates into corrugated plates to have ridges and grooves in cross section.
[0026] For example, the membrane electrode assembly 14 includes a cathode 20 , an anode 22 , and a solid polymer electrolyte membrane (electrolyte) 18 interposed between the cathode 20 and the anode 22 . The solid polymer electrolyte membrane 18 is formed by impregnating a thin membrane of perfluorosulfonic acid with water, for example.
[0027] Each of the cathode 20 and the anode 22 has a gas diffusion layer (not shown) such as a carbon paper, and an electrode catalyst layer (not shown) of platinum alloy supported on porous carbon particles. The carbon particles are deposited uniformly on the surface of the gas diffusion layer. The electrode catalyst layer of the cathode 20 and the electrode catalyst layer of the anode 22 are fixed to both surfaces of the solid polymer electrolyte membrane 18 , respectively.
[0028] At one end of the fuel cell 10 in a longitudinal direction indicated by the arrow B, a fuel gas supply passage 24 a for supplying a fuel gas such as a hydrogen containing gas, a coolant discharge passage 26 b for discharging a coolant, and an oxygen-containing gas discharge passage 28 b for discharging an oxygen-containing gas are provided. The fuel gas supply passage 24 a, the coolant discharge passage 26 b, and the oxygen-containing gas discharge passage 28 b extend through the fuel cell 10 in the direction indicated by the arrow A.
[0029] At the other end of the fuel cell 10 in the longitudinal direction indicated by the arrow B, an oxygen-containing gas supply passage 28 a for supplying the oxygen-containing gas, a coolant supply passage 26 a for supplying the coolant, and a fuel gas discharge passage 24 b for discharging the fuel gas are provided. The oxygen-containing gas supply passage 28 a, the coolant supply passage 26 a, and the fuel gas discharge passage 24 b extend through the fuel cell 10 in the direction indicated by the arrow A.
[0030] The oxygen-containing gas supply passage 28 a has a substantially triangular shape, and includes two sides in parallel to two sides of a corner of the fuel cell 10 . The oblique side connected to these two sides of the triangle is in parallel to an outer line 37 c of an inlet buffer 36 a as described later. The oxygen-containing gas discharge passage 28 b, the fuel gas supply passage 24 a, and the fuel gas discharge passage 24 b have the same structure as the oxygen-containing gas supply passage 28 a.
[0031] As shown in FIGS. 1 and 2 , the cathode-side metal separator 12 has an oxygen-containing gas flow field (reactant gas flow field) 30 on its surface 12 a facing the membrane electrode assembly 14 . The oxygen-containing gas flow field 30 is connected between the oxygen-containing gas supply passage 28 a and the oxygen-containing gas discharge passage 28 b. On the other surface 12 b of the cathode-side metal separator 12 , there is formed a coolant flow field 32 , which has a shape corresponding to the back side of the oxygen-containing gas flow field 30 .
[0032] The oxygen-containing gas flow field 30 includes a plurality of straight flow grooves 34 a along the power generation surface extending in the direction indicated by the arrow B, and also includes an inlet buffer (distribution section) 36 a and an outlet buffer (merge section) 36 b. The straight flow grooves 34 a are arranged in the direction indicated by the arrow C. The inlet buffer 36 a and the outlet buffer 36 b are provided adjacent to the inlet and the outlet of the straight flow grooves 34 a, respectively. The straight flow grooves 34 a are formed between straight flow field ridges (linear flow field ridges) 34 b protruding from the surface 12 a. Instead of the straight flow field ridges 34 b, curved, bent, or wavy ridges (not shown) may be adopted.
[0033] It should be noted that the present invention is at least applicable to the inlet buffer 36 a or the outlet buffer 36 b. Hereinafter, it is assumed that the present invention is applied to both of the inlet buffer 36 a and the outlet buffer 36 b.
[0034] The inlet buffer 36 a includes outer lines 37 a, 37 b, and 37 c forming a substantially trapezoidal (polygonal) shape in a front view. The outer line 37 a is in parallel to the inner wall surface of the fuel gas discharge passage 24 b, the outer line 37 b is in parallel to the inner wall surface (vertical surface) of the coolant supply passage 26 a, and the outer line 37 c is in parallel to the inner wall surface of the oxygen-containing gas supply passage 28 a. The outer lines 37 a to 37 c may form a triangle, a rectangle or the like.
[0035] The inlet buffer 36 a includes a plurality of continuous linear guide ridges 40 a protruding from an intermediate height area 38 a toward the oxygen-containing gas flow field 30 side. The linear guide ridges 40 a form a continuous guide flow field 42 a.
[0036] As shown in FIGS. 2 and 3 , the linear guide ridges 40 a are continuously connected to ends of the straight flow field ridges 34 b of the straight flow grooves 34 a at predetermined positions. Further, each of the linear guide ridges 40 a has a bent portion 41 a, and the linear guide ridges 40 a have different lengths in a stepwise fashion. The linear guide ridges 40 a have the same width. The width of the linear guide ridges 40 a is narrower than, or equal to the width of the straight flow field ridges 34 b.
[0037] The linear guide ridge 40 a connected to the straight flow field ridge 34 b near the oxygen-containing gas supply passage 28 a is shorter than the linear guide ridge 40 a connected to the straight flow field ridge 34 b remote from the oxygen-containing gas supply passage 28 a. The linear guide ridge 40 a includes a straight line segment 40 aa in parallel to the outer line 37 a. Further, the linear guide ridge 40 a includes a straight line segment 40 ab in parallel to the outer line 37 b.
[0038] As shown in FIG. 3 , the linear guide ridges 40 a are arranged such that intervals between connections of the linear guide ridges 40 a with the straight flow field ridges 34 b are the same distance L 1 , intervals between the bent portions 41 a are the same distance L 2 , intervals between vertical segments thereof are the same distance L 3 , and intervals between ends thereof near the oxygen-containing gas supply passage 28 a are the same distance L 4 . It is preferable that the linear guide ridges 40 a are equally arranged at the same distance L 1 , the same distance L 2 , the same distance L 3 , and the same distance L 3 at respective positions. However, the linear guide ridges 40 a may be arranged at different distances.
[0039] The inlet buffer 36 a is connected to the oxygen-containing gas supply passage 28 a through a bridge section 44 a. For example, the bridge section 44 a is formed by corrugating a seal member to have ridges and grooves. Other bridge sections as described later have the same structure.
[0040] As shown in FIG. 2 , the outlet buffer 36 b and the inlet buffer 36 a are symmetrical with respect to a point. The outlet buffer 36 b includes outer lines 37 d, 37 e, and 37 f forming a substantially trapezoidal (polygonal) shape in a front view. The outer line 37 d is in parallel to the inner wall surface of the fuel gas supply passage 24 a, the outer line 37 e is in parallel to the inner wall surface (vertical surface) of the coolant discharge passage 26 b, and the outer line 37 f is in parallel to the inner wall surface of the oxygen-containing gas discharge passage 28 b.
[0041] The outlet buffer 36 b includes linear guide ridges 40 b protruding from an intermediate height area 38 b toward the oxygen-containing gas flow field 30 side. The linear guide ridges 40 b form a continuous guide flow field 42 b. The outlet buffer 36 b is connected to the oxygen-containing gas discharge passage 28 b through a bridge section 44 b. The outlet buffer 36 b has the same structure as the inlet buffer 36 a, and detailed description of the outlet buffer 36 b is omitted.
[0042] As shown in FIG. 4 , the coolant flow field 32 is formed on the other surface 12 b of the cathode-side metal separator 12 , the coolant flow field 32 having a shape corresponding to the back side of the oxygen-containing gas flow field 30 . The coolant flow field 32 includes a plurality of straight flow grooves 46 a along the power generation surface extending in the direction indicated by the arrow B, and also includes an inlet buffer 48 a and an outlet buffer 48 b. The straight flow grooves 46 a are arranged in the direction indicated by the arrow C. The inlet buffer 48 a and the outlet buffer 48 b are provided adjacent to the inlet and the outlet of the straight flow grooves 46 a, respectively.
[0043] The straight flow grooves 46 a are formed between straight flow field ridges (linear flow field ridges) 46 b protruding from the surface 12 b. The straight flow grooves 46 a have a shape corresponding to the back side of the straight flow field ridges 34 b, and the straight flow field ridges 46 b have a shape corresponding to the back side of the straight flow grooves 34 a. The inlet buffer 48 a has a shape corresponding to the back side of the inlet buffer 36 a, and the outlet buffer 48 b has a shape corresponding to the back side of the outlet buffer 36 b (see FIG. 5 ).
[0044] As shown in FIGS. 5 and 6 , the inlet buffer 48 a includes bosses 50 a protruding from the intermediate height area 38 a toward the coolant flow field 32 side. The bosses 50 a form an embossed flow field 52 a. The depth of the continuous guide flow field 42 a from the intermediate height area 38 a is the same as the depth of the embossed flow field 52 a from the intermediate height area 38 a. The inlet buffer 48 a is connected to the coolant supply passage 26 a through a bridge section 53 a (see FIG. 4 ).
[0045] As shown in FIG. 4 , the outlet buffer 48 b includes bosses 50 b protruding from the intermediate height area 38 b toward the coolant flow filed 32 side. The bosses 50 b form an embossed flow field 52 b. The outlet buffer 48 b is connected to the coolant discharge passage 26 b through a bridge section 53 b.
[0046] As shown in FIG. 7 , the anode-side metal separator 16 has a fuel gas flow field (reactant gas flow field) 54 on its surface 16 a facing the membrane electrode assembly 14 . The coolant flow field 32 is formed on a surface 16 b of the anode-side metal separator 16 , the coolant flow field 32 having a shape corresponding to the back side of the fuel gas flow field 54 .
[0047] The fuel gas flow field 54 includes a plurality of straight flow grooves 56 a along the power generation surface and which extend in the direction indicated by the arrow B. Also, the fuel gas flow field 54 includes an inlet buffer 58 a and an outlet buffer 58 b. The straight flow grooves 56 a are arranged in the direction indicated by the arrow C. The inlet buffer 58 a and the outlet buffer 58 b are provided adjacent to the inlet and the outlet of the straight flow grooves 56 a, respectively. The straight flow grooves 56 a are formed between straight flow field ridges (linear flow field ridges) 56 b protruding on the surface 16 a. Instead of the straight flow field ridges 56 b, curved, bent, or wavy ridges (not shown) may be adopted.
[0048] The inlet buffer 58 a includes outer lines 37 a, 37 b, and 37 c forming a substantially trapezoidal (polygonal) shape in a front view. The outer line 37 a is in parallel to the inner wall surface of the oxygen-containing gas discharge passage 28 b, the outer line 37 b is in parallel to the inner wall surface (vertical surface) of the coolant discharge passage 26 b, and the outer line 37 c is in parallel to the inner wall surface of the fuel gas supply passage 24 a. The outer lines 37 a to 37 c may form a triangle, a rectangle or the like.
[0049] The inlet buffer 58 a includes a plurality of continuous linear guide ridges 62 a protruding from an intermediate height area 60 a toward the fuel gas flow field 54 side. The linear guide ridges 62 a form a continuous guide flow field 64 a.
[0050] The linear guide ridges 62 a are continuously connected to ends of the straight flow field ridges 56 b forming the straight flow grooves 56 a. Further, each of the linear guide ridges 62 a has a bent portion 41 a, and the linear guide ridges 62 a have different lengths in a stepwise fashion. The linear guide ridges 62 a have the same width. The width of the linear guide ridges 62 a is narrower than, or equal to the width of the straight flow field ridges 56 b. The linear guide ridges 62 a have the same structure as the linear guide ridges 40 a, and detailed description of the linear guide ridges 62 a is omitted. The inlet buffer 58 a is connected to the fuel gas supply passage 24 a through a bridge section 65 a.
[0051] The outlet buffer 58 b and the inlet buffer 58 a are symmetrical with respect to a point. The outlet buffer 58 b includes outer lines 37 d, 37 e, and 37 f forming a substantially trapezoidal (polygonal) shape in a front view. The outer line 37 d is in parallel to the inner wall surface of the oxygen-containing gas supply passage 28 a, the outer line 37 e is in parallel to the inner wall surface (vertical surface) of the coolant supply passage 26 a, and the outer line 37 f is in parallel to the inner wall surface of the fuel gas discharge passage 24 b.
[0052] The outlet buffer 58 b includes a plurality of continuous linear guide ridges 62 b protruding from an intermediate height area 60 b toward the fuel gas flow field 54 side. The linear guide ridges 62 b form a continuous guide flow field 64 b.
[0053] The linear guide ridges 62 b are continuously connected to the ends of the straight flow field ridges 56 b forming the straight flow grooves 56 a. Further, each of the linear guide ridges 62 b has a bent portion 41 b, and the linear guide ridges 62 b have different lengths in a stepwise fashion. The linear guide ridges 62 b have the same structure as the linear guide ridges 40 b, and detailed description of the linear guide ridges 62 b is omitted. The outlet buffer 58 b is connected to the fuel gas discharge passage 24 b through a bridge section 65 b.
[0054] As shown in FIG. 1 , the coolant flow field 32 is formed on the other surface 16 b of the anode-side metal separator 16 , the coolant flow field 32 having a shape corresponding to the back side of the fuel gas flow field 54 . The coolant flow field 32 has the same structure as that of the cathode-side metal separator 12 . The constituent elements that are identical to those of the cathode-side metal separator 12 are labeled with the same reference numerals, and detailed description thereof is omitted.
[0055] A first seal member 70 is formed integrally with the surfaces 12 a, 12 b of the cathode-side metal separator 12 , around the outer circumferential end of the cathode-side metal separator 12 . A second seal member 72 is formed integrally with the surfaces 16 a, 16 b of the anode-side metal separator 16 , around the outer circumferential end of the anode-side metal separator 16 .
[0056] Operation of the fuel cell 10 will be described below.
[0057] Firstly, as shown in FIG. 1 , an oxygen-containing gas is supplied to the oxygen-containing gas supply passage 28 a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas supply passage 24 a. Further, a coolant such as pure water, ethylene glycol, oil or the like is supplied to the coolant supply passage 26 a.
[0058] In the structure, in the fuel cell 10 , the oxygen-containing gas is supplied from the oxygen-containing gas supply passage 28 a to the oxygen-containing gas flow field 30 of the cathode-side metal separator 12 . The oxygen-containing gas moves from the inlet buffer 36 a along the straight flow grooves 34 a in the horizontal direction indicated by the arrow B, and the oxygen-containing gas is supplied to the cathode 20 of the membrane electrode assembly 14 .
[0059] The fuel gas flows from the fuel gas supply passage 24 a to the fuel gas flow field 54 of the anode-side metal separator 16 . As shown in FIG. 7 , the fuel gas moves from the inlet buffer 58 a along the straight flow grooves 56 a in the horizontal direction indicated by the arrow B, and the fuel gas is supplied to the anode 22 of the membrane electrode assembly 14 .
[0060] Thus, in the membrane electrode assembly 14 , the oxygen-containing gas supplied to the cathode 20 , and the fuel gas supplied to the anode 22 are consumed in the electrochemical reactions at the electrode catalyst layers of the cathode 20 and the anode 22 for generating electricity.
[0061] Then, the oxygen-containing gas supplied to and consumed at the cathode 20 of the membrane electrode assembly 14 is discharged from the outlet buffer 36 b along the oxygen-containing gas discharge passage 28 b in the direction indicated by the arrow A. Likewise, the fuel gas supplied to and consumed at the anode 22 of the membrane electrode assembly 14 is discharged from the outlet buffer 58 b into the fuel gas discharge passage 24 b.
[0062] In the meanwhile, the coolant supplied to the coolant supply passage 26 a flows into the coolant flow field 32 formed between the cathode-side metal separator 12 and the anode-side metal separator 16 of the fuel cell 10 , and then, the coolant flows in the direction indicated by the arrow B. After the coolant flows from the inlet buffer 48 a along the straight flow grooves 46 a to cool the membrane electrode assembly 14 , the coolant is discharged from the outlet buffer 48 b into the coolant discharge passage 26 b.
[0063] In the first embodiment, for example, as shown in FIG. 2 , a plurality of continuous linear guide ridges 40 a are provided in the inlet buffer 36 a of the oxygen-containing gas flow field 30 . The linear guide ridges 40 a have the bent portions 41 a, and have different lengths in a stepwise fashion. Likewise, the continuous linear guide ridges 40 b are provided in the outlet buffer 36 b. The linear guide ridges 40 b have the bent portions 41 b, and have different lengths in a stepwise fashion.
[0064] Thus, in the oxygen-containing gas flow field 30 , since the inlet buffer 36 a and the outlet buffer 36 b have the continuous guide flow fields 42 a, 42 b, the oxygen-containing gas does not flow around the water produced in the power generation reaction. In the structure, by the oxygen-containing gas, the water produced in the power generation reaction is easily and reliably discharged from the inlet buffer 36 a and the outlet buffer 36 b. The oxygen-containing gas can be supplied uniformly, and desired power generation performance can be maintained suitably.
[0065] Further, the areas of the inlet buffer 36 a and the outlet buffer 36 b can be reduced effectively, and the overall size of the fuel cell 10 can be reduced easily.
[0066] Further, the straight line segment 40 aa of the linear guide ridge 40 a is in parallel to the outer line 37 a, and the straight line segment 40 ab of the linear guide ridge 40 a is in parallel to the outer line 37 b.
[0067] Further, as shown in FIG. 3 , the linear guide ridges 40 a are arranged such that intervals between connections between the linear guide ridges 40 a and the straight flow field ridges 34 b are the same distance L 1 , intervals between the bent portions 41 a are the same distance L 2 , intervals between the vertical segments thereof are the same distance L 3 , and intervals between the ends thereof near the oxygen-containing gas supply passage 28 a are the same distance L 4 . The linear guide ridges 40 b have the same structure as the linear guide ridges 40 a.
[0068] In the structure, the oxygen-containing gas is supplied smoothly and uniformly along the entire power generation surface in the oxygen-containing gas flow field 30 , and suitable power generation performance can be obtained reliably. Further, in the fuel gas flow field 54 , the same advantages as in the case of the oxygen-containing gas flow field 30 are obtained.
[0069] Further, in the coolant flow field 32 , the inlet buffer 48 a and the outlet buffer 48 b have the embossed flow fields 52 a, 52 b. In the structure, improvement in the performance of distributing the coolant is achieved advantageously. The membrane electrode assembly 14 is held between the inlet buffer 36 a, the outlet buffer 36 b, and the inlet buffer 58 a, the outlet buffer 58 b.
[0070] Thus, in the fuel cell 10 , degradation of the power generation performance due to insufficient supply of the oxygen-containing gas and the fuel gas can be prevented. Further, a desired cooling function can be obtained, and the power generation of the fuel cell 10 can be performed suitably.
[0071] FIG. 8 is an exploded perspective view showing main components of a fuel cell 80 according to a second embodiment of the present invention. The constituent elements of the fuel cell 80 that are identical to those of the fuel cell 10 according to the first embodiment are labeled with the same reference numerals, and description thereof is omitted.
[0072] The fuel cell 80 includes a cathode-side metal separator 12 , a first membrane electrode assembly 14 a, an intermediate metal separator 82 , a second membrane electrode assembly 14 b, and an anode-side metal separator 16 .
[0073] As shown in FIG. 9 , the intermediate metal separator 82 has a fuel gas flow field (reactant gas flow field) 84 on its surface 82 a facing the first membrane electrode assembly 14 a, and an oxygen-containing gas flow field (reactant gas flow field) 86 on its surface 82 b facing the second membrane electrode assembly 14 b, the oxygen-containing gas flow field 86 having a shape corresponding to the back side of the fuel gas flow field 84 .
[0074] The fuel gas flow field 84 includes a plurality of straight flow grooves 88 a extending along the power generation surface in the direction indicated by the arrow B. The straight flow grooves 88 a are arranged in the direction indicated by the arrow C. Further, the fuel gas flow field 84 includes an inlet buffer 90 a and an outlet buffer 90 b provided respectively adjacent to the inlet and the outlet of the straight flow grooves 88 a. The straight flow grooves 88 a are formed between straight flow field ridges (linear flow field ridges) 88 b protruding on the surface 82 a.
[0075] The inlet buffer 90 a includes outer lines 37 a, 37 b, and 37 c forming a trapezoidal shape (polygonal shape) in a front view. The inlet buffer 90 a has a plurality of continuous linear guide ridges 94 a protruding from an intermediate height area 92 a toward the fuel gas flow field 84 side, and the linear guide ridges 94 a form a continuous guide flow field 96 a.
[0076] The outlet buffer 90 b has linear guide ridges 94 b protruding from an intermediate height area 92 b toward the fuel gas flow field 84 side, and the linear guide ridges 94 b form a continuous guide flow field 96 b. The linear guide ridges 94 a, 94 b have the same structure as the linear guide ridges 62 a, 62 b.
[0077] As shown in FIG. 8 , the oxygen-containing gas flow field 86 includes a plurality of straight flow grooves 98 a extending along the power generation surface in the direction indicated by the arrow B. The straight flow grooves 98 a are arranged in the direction indicated by the arrow C. Further, the oxygen-containing gas flow field 86 includes an inlet buffer 100 a and an outlet buffer 100 b provided respectively adjacent to the inlet and outlet of the straight flow grooves 98 a. The straight flow grooves 98 a are formed between straight flow field ridges (linear flow field ridges) 98 b protruding on the surface 82 b.
[0078] The inlet buffer 100 a includes bosses 102 a protruding from the intermediate height area 92 b toward the oxygen-containing gas flow field 86 side, and the bosses 102 a form an embossed flow field 104 a. The outlet buffer 100 b includes bosses 102 b protruding from the intermediate height area 92 a toward the oxygen-containing gas flow field 86 side, and the bosses 102 b form an embossed flow field 104 b.
[0079] In the second embodiment, the continuous guide flow fields 96 a, 96 b protruding toward the fuel gas flow field 84 side are formed in the inlet buffer 90 a and the outlet buffer 90 b on the surface 82 a of the intermediate metal separator 82 . Therefore, the fuel gas does not flow around the water produced in the power generation reaction.
[0080] Further, the embossed flow fields 104 a, 104 b protruding toward the oxygen-containing gas flow field 86 side are formed in the inlet buffer 100 a and the outlet buffer 100 b, on the surface 82 b of the intermediate metal separator 82 . Thus, in the oxygen-containing gas flow field 86 , the oxygen-containing gas flows smoothly without any influence by the shapes of the back side of the continuous guide flow fields 96 a, 96 b. | An oxidant gas conduit communicating with both an oxidant gas inlet communication hole and an oxidant gas outlet communication hole is formed in a surface of a cathode-side metallic separator which forms a fuel cell. Continuous linear guide ridges which protrude from intermediate height sections to the oxidant gas conduit side and form continuous guide conduits are provided on the cathode-side metallic separator. The linear guide ridges are continuously connected to ends of rectilinear conduit ridges which form rectilinear conduits, are provided with bend portions, and are set to lengths which are different from each other in a step-like manner. | 7 |
BACKGROUND OF THE INVENTION
Biosurfactants are substances that have received a considerable amount of attention because of the fact that they possess a wide variety of interesting properties. For example, they can be used as oil recovery agents, emulsifiers, antibiotics and antifungal agents. In fact, Arima et al. have demonstrated in 1968 Biochem. Biophys. Res. Commun. 31:488-494 that a biosurfactant such as surfactin could reduce the surface tension of water from 72 to 27 mN/m at a concentration as low as 0.005% and could also inhibit clot formation. Furthermore, Bernheimer and Avigad in 1970 J. Gen. Microbiol. 61:361-369 have shown that surfactin could efficiently lyse erythrocytes while Hosono and Suzuki in 1983, J. Antibiot. 36:679-683 have demonstrated that bacterial spheroplasts and protoplasts as well as cyclic 3',5'-monophosphate diesterase could also be inhibited by the action of surfactin.
Biosurfactants are produced as metabolic products or membrane components. A considerable number of these compounds have been characterized and described by various authors such Cooper et al. (1986, Microbiol. Sci. 3:145-149), Cooper and Zajic (1980, Adv. Appl. Microbiol. 26:229-253), Margaritis et al. (1979, Biotech. Bioeng. 21:1151-1161), Rosenberg (1982, CRC Crit. Rev. Biotech. 1:109-132), Zajic and Steffens (1984, CRC Crit. Rev. Biotech. 1:87-107). These compounds are classified as lipopeptides, glycolipids, lipopolysaccharides, neutral lipids and fatty acids or phospholipids. They are surface-active due to their hydrophobic and hydrophilic regions. Since surfactants are used in many multiphase processes, they are very important industrially. Biosurfactants are potentially less toxic and more biodegradable than the synthetic compounds currently used. They can also be produced from a variety of substrates.
In particular, lipopeptides are a very interesting class of compounds. Some examples such as amphomycin (Bodanszky et al. 1973, J. Am. Chem. Soc. 95:2352-2357 and cyclosporin A (Dreyfuss et al., 1976, Eur. J. Appl. Microbiol. 3:125-133; Ruegger et al. 1976, Helv. Chim. Acta 59:1075-1092) are respectively known for their antibiotic and antifungal activities. They contain both a lipid portion and several amino acids.
Bacillus subtilis ATCC 21332 produces surfactin. Surfactin is a lipopeptide biosurfactant having as mentioned above quite interesting properties. Apart from being a very powerful biosurfactant, surfactin has the advantage of being easily isolated in pure form when produced by microorganisms such as B. subtilis. However, serious problems are associated with the industrial production of surfactin. Among these problems, the fact that the yields are very low is certainly the most important one.
Until now, the only methods which have been utilized to enhance production of surfactin by B. subtilis are strain selection or the manipulation of environmental or nutritional factor such as described in Cooper et al. in 1981, Appl. Environ. Microbiol. 42:408-412 and Guerra-Santos et al. in 1986 Appl. Microbiol. Biotech. 24:443-448. However, the methods that have been proposed so far are indirect methods having their limitations.
Therefore, the obtention of a B. subtilis strain able to produce large quantities of surfactin would be highly desirable.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a novel Bacillus subtilis strain whose genetic material has been modified through UV mutagenesis and which may be used for producing surfactin at levels which are higher than the levels encountered when wild type Bacillus subtilis is employed. The genetically modified strain of the present invention is a mutant of Bacillus subtilis ATCC 21332 having at least one mutation between Arg4 and HisA1 sites of the genetic map of B. subtilis ATCC 21332.
In fact, when biosurfactant production by the mutant strain of the present invention is compared to that of the parent strain, it is found that the mutant strain produces as much as 3 to 4 times more biosurfactant than the parent strain in equivalent growth conditions over the same period of time.
Particularly, a subject mutant strain obtained through U.V. radiation was deposited on Sept. 21, 1988 at the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md., 20852 and was given the ATCC accession number 53813.
The mode of obtention as well as the utility of the mutant strain of the present invention will be more readily illustrated by referring to the following description.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a novel bacterial strain of Bacillus subtilis obtained through genetic mutation by ultraviolet light of the Bacillus subtilis prototroph strain ATCC 21332. The obtention of this strain allows for higher yields in the production of surfactin, a lipopeptidic biosurfactant possessing exceptional surface activity.
Obtention and selection of the mutant microorganism
The purpose of the work that lead to the present invention was to increase the yield in surfactin secretion by Bacillus subtilis through genetic manipulations. Mutation has been chosen since any change in the regulatory system of biosurfactant synthesis and secretion would result in an altered level of production.
Thus, in order to obtain a mutant B. subtilis strain producing increased amounts of surfactin, Bacillus subtilis prototroph strain ATCC 21332 may be grown to logarithmic phase and then approximately 3000 cells are plated on nutrient agar plates. The plates are then UV radiated for 35 seconds with short wave in a Chromato-Vue Cabinet Model CC-60 (UVP, Inc.). This dosage of UV light had been previously determined to give a 10 to 20% survival rate in the colonies. The UV-radiated plates are then incubated at 37° C. in the dark until the colonies are visible.
In order to detect whether the obtained colonies produce enhanced amounts of biosurfactant, the B. subtilis mutants derived from UV mutagenesis are replica plated or individually spotted onto rich medium agar plates containing 5% sheep blood cells, 4% glucose, 0.1% nutrient broth, 0.1% yeast extract and mineral salts, as described by Cooper et al. in 1981 Appl. Environ. Microbiol. 42:408-412. These plates are then screened for enhanced haemolytic activity by incubation at 37° C. and by evaluation of the haemolytic zone surrounding the colonies. It has been demonstrated by Mulligan et al. in 1984, J. Ferm. Technol. 62:311-314 that the degree of lysis of red blood cells is related to the level of surfactin production by B. subtilis.
The mutant that produces a significantly larger haemolytic zone around the colony than the other survived colonies in the parent strain is chosen. This mutant is not an auxotroph as it grew on minimal media.
Determination of the location of the mutation
The location of the mutation responsible for enhanced surfactant production is determined through protoplast fusion between the enhanced production mutant and BGSC strain 1A28 (ArgC4, HisA1 and TrpC2). This fusion may be carried out according to the method by Akamatsu and Seguchi in 1987, Mol. Gen. Genet. 298:254-262. It was determined that either a single mutation or mutations clustered in a small region of DNA that acted as a unit may be responsible for the enhanced biosurfactant production of B. subtilis. The genetic mapping of the ATCC 53813 mutant with a standard marker strain, B. subtilis IA28 demonstrated that the mutation was located between ArgC4 and HisA1 on the genetic map. Numerous mutations between these two sites could also lead to an increased production of surfactant.
Evaluation of the surfactin production of the mutant B. subtilis strain
From a sheep blood agar plate, the B. subtilis mutant strain is inoculated into a 500 ml flask containing 100 ml of 4% glucose and mineral salts medium as described by Cooper et al. in 1981, Appl. Environ. Microbiol. 42:408-412 supplemented with 3.2×10 -4 M FeSO 4 . After 3 days of growth, 10 ml of the culture is transferred to another similar flask. After 6 hours of growth, 100 ml of this media may be used as an inoculum for a 3.7 l CHEMAP fermentor.
The fermentor is operated under the following conditions: a 2.0 l working volume, a temperature of 37° C., a 5.0 l/min aeration rate and pH control at 6.7. The surfactin concentrated in the foam is removed continuously into a flask on the air exhaust line as described by Cooper et al., in 1981, Appl. Environ. Microbiol. 42:408-412.
Optical density is to be monitored at 600 nm throughout growth. Samples with optical densities above 1.0 may be diluted to obtain a reading in the appropriate range. The readings are then multiplied by the dilution factor. Surface tension of the medium may be measured using a Fisher Surface Tensiomat Model 21 which employs the du Nouy method.
Surfactin may then be isolated by adding concentrated HCl to the broth after cell removal by centrifugation as described by Cooper et al. in 1981, Appl. Environ. Microbiol. 42:408-412. The precipitated crude surfactin is then extracted 3 times with equal volumes of dichloromethane. This is followed by the removal of the solvent through evaporation under pressure. The surfactin may be further purified by redissolving in water (pH adjusted to 8.0 by the addition of NaOH), filtration through Whatman no. 1 paper, and re-extracting 3 times with the same solvent.
The amount of biosurfactant in the medium is determined by amino acid analysis. In order to do so, a 10 ul aliquot is dried and acid hydrolysed for 2.5 hours at 150° C. in a Waters PICO-TAG Amino Acid Analysis System. The residue is then redissolved in 200 ul of sodium buffer and injected on a Beckman System 6300 High Performance Analyser equipped with a Beckman Model 7000 Data Station. Analyses are performed according to the general procedures described by Spackman et al. in 1958, Anal. Chem. 30:1190-1206. The ratio of aspartic acid, glutamic acid, valine and leucine is found to be approximately 1:1:1:4 for the compounds produced by each strain. This ratio is similar to the amino acid composition of surfactin shown by Kakinuma et al. in 1969 Agric. Biol Chem. 33:1669-1671.
Further confirmation of the structure of the biosurfactants may be obtained by mass spectrometry. Based on the surfactin molecular formula (C 53 H 93 N 7 O 13 ), the protonated molecular weight is 1036.6909. The spectra of the compounds produced by the parent strain shows similar fragmentation patterns with respective M + of 1036 and 1037. The mass spectra were obtained on a VG Analytical ZAB-SE double focussing mass spectrometer. The accelerating voltage was 10 kV and the fast xenon atom beam was operated with an emission current of 1 mA at 8 kV. Mass spectra were recorded with the data acquisition and calibration was performed with CsI.
Surfactant production was compared to the production of surfactin by Bacillus subtilis ATCC 21332 under similar growth conditions. Results shown in Table 1 demonstrate that the mutated strain of the present invention can produce at least 3 to 4 times more biosurfactant than the parent strain over the same time period.
TABLE 1______________________________________Comparison of the growth and the amountsof biosurfactant produced by B. subtilisand the mutant strain of the present invention Amount of Growth after 40 hours surfactinStrain (Optical density at 600 nm) produced (mg)______________________________________ATCC 21332 8.2 328ATCC 53813 8.3 1124______________________________________ | A B. subtilis strain possessing an enhanced surfactin production potential. The strain is a mutant of B. subtilis ATCC 21332 and has at least one mutation between Arg4 and HisA1 sites of the genetic map of B. subtilis ATCC 21332. Also included in the present invention is B. subtilis strain having the identifying characteristics of ATCC 53813. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of a copending U.S. patent application Ser. No. 716,149, filed Mar. 26, 1985, now abandoned, which is a division of then-copending U.S. patent application Ser. No. 552,061, filed Nov. 15, 1983, now U.S. Pat. No. 4,512,060, which is in turn a continuation-in-part of then-copending application Ser. No. 428,608 filed Sept. 30, 1982, and now abandoned. A concurrently-filed related application entitled "Conditioned Gas Flow Methods for Processing and Cleaning Fiber, Including Aeromechanical and Electrodynamic Release and Separation of Foreign Matter from Fiber" is Ser. No. 826,903, filed Feb. 6, 1986, which is a continuation of Ser. No. 716,175, filed Mar. 26, 1985, now abandoned, which is also a division of application Ser. No. 552,061, now U.S. Pat. No. 4,512,060.
BACKGROUND OF THE INVENTION
The present invention relates to methods and machines for the release and separation of foreign matter from fibers such as cotton. The invention is applicable to two distinct purposes: (1) providing apparatus for precise and accurate laboratory measurement of foreign matter in fiber; and (2) providing apparatus applicable to high production rate fiber processing machinery.
Increasing demands are being placed on fiber properties as textile processing machinery production rates increase and as the tolerances of textile processing machinery for variances in the fiber properties decrease. Current production and harvesting methods inherently entrain more foreign matter content into cotton fiber, for example, such that the ginning and cleaning actions required to achieve a given percentage of foreign matter content are increasing. Increased cleaning is always at the expense of fiber loss and damage. The incompatibility between the goals of clean versus undamaged fiber increases the difficulties faced by producer, ginner, buyer and spinner. Providing clean and undamaged fiber is a major, world-wide problem and new methods of cleaning are urgently needed.
Foreign matter diminishes the value of the fiber because it causes processing problems and because it causes degradations of the yarn. Removal of foreign matter is always at the expense of fiber loss and fiber damage. The designer or operator of cleaning and processing equipment must, using prior art machines, make difficult and economically unattractive trade-offs between cleaning and fiber loss and damage.
Release and separation of foreign matter are important not only in processing applications. In particular, removal of foreign matter is important in instrumentation and measurement applications. Fiber properties are being determined with increasing accuracy, precision, and completeness as a consequence of new instruments for the measurement of four basic properties: length, strength, color, and fineness. Other properties and/or better ways of measuring conventional properties are under investigation. For a detailed discussion, see F.M. Shofner, W.F. Lalor, J.H. Hanley, "A New Instrument for Trash and Microdust Measurement in Raw or Processed Cotton", presented at the Natural Fibers Textile Conference, Charlotte, N.C., Sept. 14, 1982 and published under the revised title "A New Method for Microdust and Trash Measurement and Bale or Process Fiber" in Textile Research Journal, February 1983, Vol. 53, No. 2. Measurements of the above four basic properties have been automated and, with a determination of grade by a human cotton classer, have been assembled into High Volume Instrument (HVI) test lines which are increasingly used by the U.S. Department of Agriculture for setting the class of cotton, which determines its price. Thus grade is primarily influenced by foreign matter content and another urgent need exists to provide this measurement for use on HVI lines.
The present invention is concerned primarily with the bulk fiber property of foreign matter content ("trash", "dust", "microdust", respirable dust", and the like) in cotton or other fibers, and the effective removal of this foreign matter with low fiber damage and losses. Embodiments of the invention are designated "MTM", Microdust and Trash Machine. (Note: In the above-referenced Shofner et al article, MTM is used as an acronym for Microdust and Trash Monitor.)
Releasing and separating the foreign matter from the cotton permits its more accurate measurement with, for example, modern electro-optic means as described in Shofner et al U.S. Pat. No. 4,249,244. The above-referenced Shofner et al article, as well as FIG. 1 described hereinafter, generally show how electro-optical methods can be used to advantage once the foreign matter is released from the fiber and fiber and various dust components are separated into different pneumatic transport flows.
Prior art apparatus exists which cleans fiber for measurement purposes or for processing These include the Shirley Analyzer (see "Standard Test Method for Non-Lint Content of Cotton", Designation: D 2812-81, reprinted from the Annual Book of ASTM Standard, Philadelphia, PA), as well as conventional lint-cleaning equipment which are generally effective in large particle removal. However, these machines cannot possibly achieve high effectiveness in release and separation of small dust and microdust particles. They damage fiber severely if it is attempted to remove small particles with them.
Of significant importance in the context of measurement is the fact that the present invention permits release and separation and according to the following aerodynamic size classifications recently established by the International Committee on Cotton Testing Methods. (Note, AED=Aerodynamic Equivalent Diameter.):
Trash: AED>500 μm
Dust: 50 μm<AED<500 μm
Microdust: 15 μm<AED<50 μm
Respirable Dust: 0 μm<AED<15 μm
My colleagues and I have suggested in the above-referenced Shofner et al article that a slightly better terminology is:
Trash: AED>500 μm
Dust: 50 μm<AED<500 μm
Microdust: 0 μm<AED<50 μm
thus making OSHA respirable dust a special case of microdust.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide methods and apparatus for release and separation of foreign matter content by the proper application of aeromechanical and electrodynamic forces while minimizing fiber damage or loss.
Another object of the invention is to provide an improved measurement system for the foreign matter content in cotton. The improved measurements result because the forces applied to the particles permit a more effective release and precisely-controlled separation according to aerodynamic size in contrast to prior art devices which are less controlled generally and fail specifically on small particles.
Another object of the invention is to use the fiber thus cleaned and blended and operated upon for improved measurements of the fiber properties themselves. That is, removing the foreign matter and processing the fiber leads to truer fiber property measurements; these data are obviously less biased by the foreign matter and are therefore more accurate. In addition, they are more precise as a consequence of the processing.
A still further object of the invention is application to commercial-scale lint or fiber cleaning, as opposed to laboratory instrumentation application. Lint cleaners in gins can be substantially improved by the principles of the invention. Similarly, textile processing machines such as opening/cleaning, carding, or open-end spinning equipment can produce better (cleaner and less-damaged) outputs. Additionally, losses of good fiber can be reduced.
Yet another object of the invention is application of the apparatus of the invention, in proper combination with well-known pre- and post-processing means, in a total system for conversion of tufts of fiber into yarn with heretofore unknown speeds, quality, and cost-effectiveness. Pre-processing means include opening, precleaning, and transporting fiber to the MTM apparatus. Post-processing means include open-end (or any other type) spinning method(s) which can take the individualized, cleaned, blended and worked fibers and spin them into high quality yarn.
The invention, reduced to its most basic contributions, provides for application of cleaning (i.e. release and separation) forces heretofore impossible and futher provides for heretofore unrealized minimums of fiber loss and damage. A major embodiment is the "counterflow separation slot" which is one thrust of this disclosure.
Briefly stated, apparatus in accordance with the invention comprises what resembles a conventional pinned or toothed cylindrical rotating wheel such as an individualizing and cleaning wheel or a beater wheel. In general, cotton tufts are inserted into the machine to engage the teeth or pins, carried with the wheel part way around, and then removed or doffed as individualized and processed fiber.
Within this overall context, one important aspect of the invention is the provision of perforations on the cylindrical surface of the wheel, and a radial suction port for drawing transport gas through these perforations. The transport gas carries with it microdust, which, in instrumentation applications, can be measured.
Another important aspect of the invention is the provision of counter flow slots oriented generally tangentially with respect to the beater wheel and positioned with respect to the direction of wheel rotation such that dust and trash particles are thrown into the slot. At the same time, transport gas flows in a counter direction. The larger dust and trash particles escape, while microdust and fibers are turned back by the counter flow. In instrumentation applications, the escaping dust and trash can be measured.
Preferably, perforated wheels and counter flow slots are combined in a single machine.
Another important aspect of the invention is the conditioning of the transport gas as to humidity, for example, before entering the machine. Air into the machine can be far more economically and accurately conditioned than the general ambient air in the work place, thus providing fundamental advantages in measurement and processing. Other examples of conditioning the inlet gas stream are according to the parameters of: temperature, pressure, gas composition, free charge concentration (ions), radioactive particle concentration, and velocity and pressure fluctuations.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a diagrammatic view of a basic two-stage apparatus in accordance with the invention;
FIG. 2 is a generalized depiction of a counterflow separated slot, defining various parameters;
FIG. 3A, 3B and 3C depict three representative forms of counterflow slots, herein termed "Type A", "Type B", and "Type C" counterflow slots;
FIG. 4 depicts an aeromechanical separator machine in accordance with the invention, which machine utilizes serpentine feed, employs five counterflow slots, two microdust removal points, and pinned and perforated cylinders;
FIG. 5 depicts another machine embodiment in accordance with the invention employing high speed feed roll/feed plate input;
FIG. 6A is an end view of a typical perforated and pinned cylindrical wheel in accordance with the invention;
FIG. 6B is a longitudinal section along line 6B--6B of FIG. 6A; and
FIG. 6C is a greatly enlarged view of a portion of the circumference of the wheel of FIG. 6A.
DETAILED DESCRIPTION
Referring first to FIG. 1, a two-stage separation apparatus in accordance with the invention includes a conventional feed roller 10/feed plate 12 arrangement in combination with a toothed first stage individualizing and cleaning wheel or beater 14 of hollow cylindrical configuration. While the wheel 14 is illustrated as having teeth, hardened pins in a helical pattern may alternatively be employed. The rotational speed of the first stage wheel 14 may be in the range of from 50 to 5000 RPM, and is nominally around 3000 RPM. The wheel 14 is roughly similar to the licker-in of a conventional carding machine or the beater stage of an open-end spinning head, with, however, the important exception of perforations 16, which in accordance with the invention, allow flow radially into the wheel 14. Pneumatic or physical transport of raw stock 18 (for example, cotton tufts) into the feed roller 10/feed plate 12 is accomplished by any of a number of conventional techniques, for example, by a condenser arrangement.
From the first stage wheel 14, fiber is transferred as at point E to a rotating second stage wheel 72 by toothed- or pinned-wheel transfer or pneumatic "doffing", or both. Finally, the fiber is removed or "doffed" as at 22 from the second stage for subsequent measurement or processing. The various transfers briefly summarized above are, in general, well known in the art.
Having generally described the manner in which cotton tufts are inserted into the FIG. 1 machine and individualized, cleaned, and processed fibers are removed from the machine, described now in detail are the methods of proper application of aeromechanical and electrodynamic forces in accordance with the invention for the controlled release and separation of foreign matter from the fiber. While these methods are described in the context of the two-stage machine of FIG. 1, it should be noted that for some applications a single-stage apparatus is sufficient. The novel features will be seen to be equally advantageous for measurements and for processing.
Tufts of randomly oriented fiber 24 are gripped by the feed roll 10/feed plate 12 combination and engage teeth 26 of the first stage or beater wheel 14. This action combs the fibers 28 and imparts large impact forces preferentially to the large, dense particles in the fiber, striking them toward a trash tube 30 with trajectories between those represented at A and B. The fibers are hooked by the teeth 26 and quickly accelerated to the peripheral speed of the first stage wheel 14 when they are released from the gripped tuft.
Conditioned inlet air 36 or other transport gas is directed toward the beater wheel 14 in a crossflow manner so that particles smaller than, for example, 500 μm aerodynamic equivalent diameter (AED), do not enter the trash tube 30. That is, particles having AED>500 μm are "knocked" across the inlet crossflow 36 into the trash tube 30. Particles having AED<500 μm however move into a separation gap 42. The trajectory lines A and B permit aerodynamic definition of the particle size captured. The lower cut-off, AED=500 μm in this illustration, results from balances between the outward centrifugal and inward aerodynamic drag forces on the particles.
One or more lint bars 38 may be employed to aid in the removal by preferentially holding fibers on the beater wheel 14 causing more sharply accelerating flow 40 to accelerate trash particles outward into the separation gap 42.
Trash particles thus removed and classified may then be measured by electro-optic 44 or gravimetric 46 means. A suitable electro-optic sensor employs continuous aerosol monitor (CAM) technique disclosed in Shofner et al U.S. Pat. No. 4,249,244. Modified CAM sensors 44 have proven to measure the total trash mass or weight and to provide particle size classification or mass fraction analysis. These same particles may be captured on filter materials 46 for weighing and, in some cases classification, both using means well known in the art.
At the other extreme, microdust, that is particles small than, for example AED<50 μm, is drawn into the perforated cylinder 14 through the holes 16 by aerodynamic drag forces effected by a radially inward air flow component represented at 48. The inward flow 48 is controlled to preferred circumferential regions by a semi-cylindrical air blocking sleeve 50. The separated microdust is then pneumatically transported through a radial port 1 (52) and thence to an electro-optical 54 or gravimetric 56 weighing means. Suction is applied to the radial port 1 (52) to draw the air or other transport gas through the machine and, in particular, through the perforations 16.
This microdust removal and separation means is both novel and of fundamental importance. Sharply-defined aerodynamic classification results from this application of two opposing forces. Particles which are released are separated because AED>50 μm particles cannot go into the cylinder 14 since their large outward centrifugal force overpowers their inward aerodynamic drag force.
On the other hand, fibers, whose AED's are also <50 μm, do not enter the perforations 16 because of their length. fibers fragments whose lengths are about the same diameter as the holes do enter and are properly classified as microdust.
This leaves the dust particle class between 50 μm and 500 μm. By proper balance of various design and operating parameters such as cross flow 36, perforated wall flow 58, and the direction and dimensions of the separation gap 42, the particles between 50 μm and 500 μm are separated into the dust tube 60 from which they are pneumatically transported along trajectory C into electro-optical 64 or gravimetric 66 measurement apparatus.
At point D is a separation stripper 70 which defines the final cut in AED for the first stage. It is most important to note, in the vicinity of points C and D, that air is moving into the wheel 14 and into the dust tube 60. Larger particles move outward across or counter to the inward flow 70 and into the dust tube 60. This is one embodiment of the counter flow slot concept described in detail hereinafter with reference to FIGS. 2-6.
It will be appreciated that this apparatus effectively addresses both the requirement for the release of dust from the fiber, and the separation of the dust and the fiber from the system. It is one thing to release dust from the fiber, and quite another to separate it from the system.
In some cases, strong adhesion of the particles necessitates a second, more vigorous or aggressive stage. Careful attention must be paid to the density of fiber (mass per unit area) on the wheels. If the density is high, removal of the foreign matter from the fiber is less effective and fiber damage can result. But low density means low processing rates which results in longer processing times and/or costs. Thus for more effect removal, the second stage provides forces which can be much higher because the fiber has been opened and combed and because the fiber density can be much lower.
Fiber is transferred to the second stage cylindrical wheel 72 at Point E. The peripheral velocity of the second stage cylinders 72 is much higher, and stronger release and separation forces can be applied. (Which, again, are distinct forces.) In addition, the density of the fiber on the second stage wheel 72 is relatively tenuous compared to the first stage wheel.
A second counterflow slot is placed at point F. While the principles of counterflow slots are described in detail below with reference to FIG. 2-6, it may here briefly be noted that large (e.g., AED>50 μm) particles removed by impaction and combing and whose momentum overcomes the inward flow drag are separated into the dust tube 76, 76' and combined with the dust from the first stage along the trajectory C.
To aid in microdust release and separation, a source G of blast air 80 is provided at a point between the point E where fiber is transferred to the second stage wheel 72 and the point 22 where the lint mat is doffed. The lint itself does not pass through the perforations, which are typically about 0.0060 inch (˜1.5 mm) in diameter and provide in the order of 25% open area.
The lint, whose AED<50 μm, is held onto the cylinder 72 by the inward flows 78 and by the "hook" action of the teeth. Again, the length of the lint precludes its movement through the holes in the perforated wheels, even then the forces are very large, as with the microdust blast air G.
Carding action is employed as at point H, and is commonly recognized as effective in microdust release. Conventional carding machines however do not employ inward flows as at 84, or pulsating (i.e. acoustical) flows for microdust removal, as at 86. As in the case of the first stage, the radially inward flows 78 and 84 are provided by suitable holes between the teeth so that clean air or other transport gas may move first through the external pins 88 ("flats") into the perforated wheel 72.
Between the card pins 88 and wheel teeth 90 mechanical combing, aerodynamic, forces as at 92 are applied to the fiber (and to the dust particles) causing the fiber to more effectively engage the pins and thereby further release microdust.
An exemplary electrodynamic force is provided by a static or DC voltage 92 applied between the pins 88 and the second-stage wheel 72. Alternatively, an alternating voltage in some cases more effectively causes release. In yet other cases, undesirable electro-static forces which render less effective particle release or which cause fiber damage may require charge neutralization. This can be accomplished with electrical 92 or radioactive means.
It may be noted that application of electrostatic forces 92 to fibers is heretofore known, but not for the purpose of aiding cleaning and not in combination with the components of the FIG. 1 embodiment.
Microdust thus removed and separated is similarly transported by suction into radial Port 2 (94) and to the microdust sensing means, which may be electro-optic (54) or gravimetric (56).
In brief summary of FIG. 1, in accordance with the invention there is provided a proper combination of various aeromechanical and electrodynamic forces, especially including radially inward, aerodynamic drag forces, for the controlled release and separation of foreign matter from fiber. The separation is into pre-determined aerodynamic equivalent diameter (AED) classifications such as (1) Trash: AED>500 μm; (2) Dust: 50 μm<AED<500 μm; and (3) Microdust:AED<50 μm.
The third of the above classifications, AED<50 μm, in turn includes a subclass, respirable dust, as defined by OSHA, AED<15 μm. This subclass is advantageously further classified by the CAM electro-optical method of U.S. Pat. No. 4,249,244. This CAM method permits E-O classification of the trash and dust components as well.
The resultant lint removed at 22 by centrifugal or aerodynamic forces has been cleaned, processed and blended. The fibers are generally individualized and are in an ideal state for electro-optical measurement as at 98, or for further processing, as for example, open-end spinning as described in J. I. Kotter, D. P. Thibodeaux, "Dust-Trash Removal by the SRRC Tuft-To-Yarn Processing System", Journal of Engineering for Industry, Vol. 101, No. 2, May, 1979. Fiber property measurements are discussed hereinafter.
The apparatus of FIG. 1 embodies a number of basic principles and concepts in accordance with the invention whereby new and properly controlled forces are applied to remove and separate foreign matter from lint. One particularly significant aspect of the invention is the counterflow slot concept mentioned briefly with respect to FIG. 1 counter flow slots at C and F, and described in detail hereinafter with reference to FIGS. 2-6. In general, the embodiments of FIGS. 2-6 emphasize aeromechanical release and separation.
As the term is employed herein, a counter flow slot is a slot-like conduit or opening wherein flow of different constituents occurs in opposite directions at the same time. In general, air flows in one direction, and the relatively larger dust and trash particles (in contrast to microdust) flow in the opposite direction, i.e., counter to the airflow.
FIG. 2 depicts the general structure and defines the basic parameters of counter flow slots. In FIG. 2, the actual counter flow slot into which dust and trash particles are thrown by rotational force of a representative wheel 112 is designated 100. To achieve this result, the slot 100 is oriented generally tangentially to the wheel 112 and properly positioned with respect to the direction of rotation of the wheel 112. The slot 100 communicates with a collector tube 102 out of which dust and trash exit at 114. A pair of elongated openings 104 and 106 allow airflow to enter, which branches in two directions to flow in the slot 100 and the collector tube 102. It will be appreciated that this general structure is subject to numerous variations.
In FIG. 2, it will be appreciated that the cross-hatched boundary portions of the slot 100 run parallel to the axis of rotation of the main cylinder 112. The collector tube 102 inlet also runs axially, but its flow Q c is drawn into a round conduit 114 for the pneumatic transport of the dust plus trash to the disposal or measuring means, as for example, a CAM sensor 44 or 64, as in FIG. 1.
The parameters defined in FIG. 2 are the following:
L=length of the slot 100
W s =width of the slot 100
W c =width of the collector tube 102
S=spacing between slot 100 and collector tube 102
Q s =airflow rate into the slot 100
Q c =airflow rate into collector tube 102
The manner in which action of the slot 100 in combination with a perforated cylindrical wheel perform aerodynamic separation and classification will now be described in greater detail. Fiber and foreign matter particles are thrown into the slot 100 by the rotational force of the cylindrical wheel 112 and move in a sense that is generally counter to the flow of air Q s into the slot 100. On the other hand, fibers have AED<50 μm, typically, and, along with foreign matter particles having AED<50 μm, are turned around and drawn back toward the cylinder 112 by the airflow Q s . Lint is thus recaptured by the pins or teeth of the cylinder 112 and carried with the cylindrical wheel 112 and carried with the cylindrical wheel 112. Small particles are drawn toward the cylinder 112 and, if sufficiently small such that the aerodynamic drag forces overcome the centrifugal acceleration forces, they are drawn inside if it is perforated. As noted above, this is a sharply-defined and easily-controlled aerodynamic classification mechanism and is one of the major aspects of the invention. Large particles, having greater momentum or longer stop distances, also move counter to the incoming slot flow and, if they reach the inlet of the collector tube 102 are thereby caught and transported outward for measurement or simple removal purposes.
It has been found that another major feature of the counterflow slot is elimination of individual lint or fibers leaving the system. This accomplishes a major, heretofore impossible objective: retaining lint particles within the system. Prior art machines necessitated a difficult tradeoff between cleaning efficiency and fiber loss by allowing a certain amount of fiber to be ejected from the system along with the foreign matter. This can be very uneconomical because, in some systems, for each incremental unit weight of foreign matter ejected, a roughly equal unit weight of good fiber is thrown from the system.
It is noted that some fiber will be thrown out of the counterflow slot 100 of FIG. 2 but it is always attached to more aerodynamically massive entities. These components of the fiber are undesirable for processing viewpoints in any event, and include motes, seed coat fragments, and fibers so intimately entwined with foreign matter that they could not be processed.
To restate a major benefit of counter flow slots: good, individualized fiber is not thrown from the slot.
From FIG. 2, it will be appreciated that the designer (and even operator) of fiber cleaning equiment has at his disposal a heretofore unknown range of effective operational parameters with which to adjust the cleaning efficiency of the machine. The slot parameters may be adjusted in combination with the physical dimensions and speeds of the main cylinder 112 to achieve predetermined aerodynamic cut-offs and efficiencies of removal.
The aeromechanical separation principles of the basic counter flow slot of FIG. 2 may be embodied in a number of forms. For convenience, three overall forms are herein designated Type A, Type B and Type C, and illustrated in FIGS. 3A, 3B and 3C, respectively.
In the Type A form of FIG. 3A, air or transport gas is drawn at 130 into a perforated main cylinder 132. The circumferential extent 131 in which slot air 130 flows is defined by a blocking sleeve 134.
In the Type B form of FIG. 3B, air or transport gas is drawn at 140 into a slot around a stripper bar 142. Both lint and small particles are transported to a subsequent stage whose basic parameters may be adjusted to allow aerodynamic separation cuts which are for smaller particles and which are sharper in their performance. However, unless either a perforated cylinder or perforated wall (as illustrated in FIG. 3C described next is employed), the microdust is not separated from the lint.
The Type C form illustrated in FIG. 3C results in a construction which is less expensive than the Type A form and about equally effective in the removal of foreign matter. In this case, the lint is pneumatically transported at 150 along with the foreign matter which has been removed by the action of a non-perforated main cylinder 152 in transfer from a feed or input cylinder 154. Particles are then subsequently separated from the lint in three mechanisms in FIG. 3C: (1) through a perforated wall 156 (Recall that the fiber density is low so that the particles have an opportunity to migrate through the tenuous fiber mass into the perforated wall); (2) at the counterflow slot 158 (shown here as a single-entry slot); and (3) microdust and possibly dust into the perforated cylinder 162.
The Type C embodiment of FIG. 3C provides a more economical construction for at least two major reasons. First, the smaller perforated working cylinder 162 and blocking sleeve 164 are less expensive in their constructions. Second, this adaptation may be retrofitted to a variety of existing lint-cleaning equipment for which perforated main cylinders would be prohibitively expensive and/or unavailable.
It will be appreciated that numerous other configurations of counterflow separation slots are certainly possible, and there is no intention to limit the invention to the specific embodiments illustrated herein.
FIG. 4 illustrates an embodiment of the invention which is constructed of practical elements and which has been thoroughly tested. Fiber is drawn by a belt/slide arrangement 200 into a conventional feed roll 202/feed plate 204 configuration. A first or opening cylinder 206 combs the fiber around the feed plate 204 and removes foreign matter, preferentially large foreign matter or trash, which is then separated into a first counter flow slot (CFS 1) 206, shown as a single entry slot.
The fiber, which is hooked onto the forward raked pins of the combing cylinder 206 is then transported into an input or feed cylinder 208 having pins 210 which intersects with pins of the combing cylinder 206. The fiber is transported in a serpentine fashion such that both sides of the fiber mat are acted upon or cleaned. The input cylinder 208 is typically moving at a much higher speed than the combing cylinder 206 and foreign matter is aeromechanically released and separated using a second counter flow slot (CFS 2), illustrated as a double-entry slot. The fiber is then transported to a main, high-speed cylinder 212, again in a serpentine fashion. Vigorous aeromechanical separation 214 takes place at the inlet of the counterflow slot 216, shown here as a Type A slot as in FIG. 3A (air into cylinder slot) and provides a third opportunity for removal of foreign matter. In this case dust and trash are thrown out into a third counter flow slot (CFS 3) and microdust is drawn into the perforated cylinder 212 at 218.
The inward drag forces disappear at the beginning of the blocking sleeve 220. The lint is thus removed from the main cylinder 212 and thrown onto a second-stage worker cylinder 222 which then transports the fiber around for a second engagement with the main cylinder 212. The second engagement is not serpentine but is in the form of a high-speed feed roll 222/feed plate 224 combination.
At this point, a fourth counterflow slot (CFS 4) 226 operates also as a Type A air into cylinder slot. Also, microdust is drawn into the perforated main cylinder 212 at 230.
The process is repeated for the third stage with the only difference being that a fifth counterflow slot (CFS 5) 227 is a Type B (air over cylinder). In this case, the air 228 drawn into the slot is also used to penumatically doff and transport the lint out of the system for subsequent processing or measurement use.
It is worth re-emphasizing at this point that the lint thrown out of the machine is individualized and has been cleaned and processed. This fiber is in a preferential state for measurement or further processing.
In summary, FIG. 4 thus illustrates the application of five counterflow slots of various designs in a single machine. In addition, there are two microdust capture points 218, 230 making a total of seven opportunities to remove foreign matter from the lint. It has been determined from extensive experimentation with this apparatus that considerable advantage is realized when multiple opportunities for foreign matter removal are offered. These advantages result in both more complete foreign matter and in less fiber damage and loss.
In the interest of completeness of disclosure, it is reported herein that apparatus having the following basic parameters have proven successful:
______________________________________ Dia- Pins Den- meter Speed Height An- sityCylinders Inches RPM Inches gle #/in.sup.2 Pattern______________________________________Combing 3 10-300 1/4 9° 16 CircularInlet 3 60-3000 1/8 9° 50 CircularMain 6 2000-4000 1/8 9° 100 HelicalWorkers 3 50-5000 1/8 9° 50 Helical______________________________________ Q.sub.s L W.sub.s Q.sub.c W.sub.cCounterflow Slots CFM in in CFM in______________________________________1 3 3 1/2 5 3/42 10 2 1/2 5 3/43 25 11/2 1/2 5 3/44 15 11/2 1/2 5 3/45 35 1 3/4 5 1______________________________________
Two machines in particular have been constructed, respectively having approximately 1-inch and 81/2 inch axial extents. The above data are for the 81/2 inch machine.
A further comment concerning the use of pins and especially intersecting pins 210 is in order. Conventional, prior art, lint-cleaning equipment uses either teeth 26, as illustrated in FIG. 1, or hardened pins as illustrated on cylinders 206, 208, and 212 in FIG. 4. It has been found that the hardened pin construction offers significant advantages with regard to operating life of the cylinder and with regard to fiber damage.
The intersection of pins 210 between the combing 206 and feed 208 cylinders has been found advantageous for complete fiber transfer between these two cylinders and also because it affords a good opportunity to comb or align the fibers in addition to providing aeromechanical release and separation forces. It is of significance that the fiber fed into the main cylinder is less dense than in prior art machines and furthermore the fibers have been drawn or drafted by the two inlet stages.
FIG. 5 shows another embodiment using the same aeromechanical separation equipment as for FIG. 4 but using a different feeding arrangement. Rather than the serpentine pattern of FIG. 4, the fiber is fed from the inlet cylinder 300 in a conventional feed roll 300/feed plate 302 arrangement. Fiber is more aggressively combed in this manner and in some cases the attendant higher fiber damage rates are acceptable in balance with the improved combing and release and separation of foreign matter. The serpentine pattern is retained for the combing cylinder 303 except that the stock feed roll 202/feet plate 204 of FIG. 4 has been eliminated to show yet another embodiment of the feed stages of the machine.
In application of the machine to high volume instrument HVI cotton classing, it has been found that the condition of the fiber influences the results. Moisture content, static charge, and state of relaxation materially affect not only the foreign matter removal efficiency and fiber damage of the machine, but subsequent other fiber property measurements as length and strength as well. These findings are equally applicable to processing machinery applications.
A most important consequence of the counterflow slot design as embodied for example in FIG. 5 results. The air or other transport gas fed into the machine at the counterflow slots 304, 306, 308 and at the inlets 309 and 311 may be controlled in its humidity and electrostatic charge quality so that the operation of the aeromechanical release and separation means can be on preferred states of the fiber with regard to humidity and static charge. That is, the air into the machine can be far more economically and accurately conditioned than the entire air in the work space, thus providing fundamental advantages for measurement and processing. It is furthermore clear that the humidity and electrostatic charge of the fiber may be different at each of the different processing stages simply by controlling the air fed into the system at the various counterflow slot points.
The physical state of the fiber presented at 320 to the Microdust and Trash Machine has proven to be of similar fundamental importance with regard to foreign matter release, processing speed, and fiber damage. Thus in FIG. 5 a perforated belt-feed system 330 draws 332 conditioned air 334 through the feed table 336.
Yet another physical property, the state of relaxation of the fiber, has proven important in MTM processing. Fiber from tightly compressed bales can be relaxed by first plucking small tufts from the mass and then transporting them to the feed table 336 of FIG. 5. This may also be easily done by replacing the feed table with a standard condenser which is well known in the art. Obviously, the air drawn into the condenser may be similarly conditioned as at 336 in FIG. 5. The fibers can be given preferential alignment and can be deposited in a more blended, more uniform mat.
FIGS. 6A, 6B and 6C show in detail a typical perforated cylinder in accordance with the invention, and the method by which air is drawn into the perforated cylinder. FIG. 6C in particular illustrates the arrangement of the pins 402 and the perforation holes 404. Air is drawn into the holes 404 by a cylindrical blocking sleeve which slips into from the cylinder right-hand and as seen in FIG. 6B. (FIG. 5 shows an end view of the blocking sleeve 34.) The blocking sleeve axial slots cut at the preferred circumferential locations and draw mirodust-laden air in, as in FIG. 4 (at 218, 230) or FIG. 5 (at 342, 344, 346). Air is drawn out of the cylinder by any suitable means.
The following are typical dimensions for the pinned, perforated cylinder of FIGS. 6A, 6B and 6C. In FIG. 6A, the pins are angled with respect to imaginary radial lines by an angle α, typically 9°; and the circumferential spacing s between pins is typically 0.1 inch. In FIG. 6B, the inside diameter a is 4.625 inches; the diameter b is 4.875 inches; the diameter c is 5.375 inches; the diameter d is 5.611 inches; the pin height e is 3.0 mm (0.118 inches); the diameter f is 1.0 inch; the diameter g is 2.0 inches; the spacing h is 1.0 inch; the spacing i is 1.25 inches; along the length of the cylinder the portion j has approximately eighty pins on a 0.1 inch spacing for a total of 8 inches, and arranged in a helical pattern; the cylinder length k is 91/8 inches; the dimension 1 is 11/8 inches; the dimension m is 3/8 inch; the dimension n is 1/2 inch; the dimension p is 3/4 inch; the dimension q is 1/8 inch; and the dimension r is 1/4 inch. In FIG. 6C, the pins 402 have a diameter of 0.040 inch, and the holes 404 have a diameter of 0.060 inch.
Reconsidering FIG. 4 in light of FIG. 6 it may be noted that microdust-laden air 218, 230 is transported out of the internal parts of the main cylinder 212 and blocking sleeve 220 as described above and into a single pipe. Similarly, the flow for the five counterflow separation slots of FIG. 4 may be either individually transported into measurement apparatus, such as electro-optical sensors 44, 64 illustrated in FIG. 1 or, may be combined into a single conduit 60. The individual flows Q s for the five slots in FIG. 4 are adjusted simply by providing variable restrictions in the flow lines, as is well known in the art.
Combining all of the dust plus trash thus released and separated by the MTM provides yet another meritorious use of electro-optical sensing. Since it is desired to know the relative amounts of dust (50 μm to 500 μm AED and trash (>500 μm AED), the electro-optical sensing means may be used to provide characterization of these components. Still further, the modified CAM sensor permits mass fraction resolution into perhaps eight sized channels, beginning at 50 μm.
The point of this observation is that the aeromechanical separator of FIG. 4 basically has one, sharply-defined cut point at AED 50 μm. This is a simplification and in some measures an improvement over the embodiment of FIG. 1 where trash, dust and microdust all are aerodynamically defined. The requisite resolution of the dust and/or trash components is in this embodiment is advantageously performed with electro-optical measures.
It is also noted that the common dust plus trash catch may be subsequently analyzed by other methods such as sieve analysis, cascade impaction, and the like. However, these gravimetric means are not easily amenable to high-speed measurements required for high volume instrument testing purposes.
As a final observation, it is noted from FIG. 1 that the cleaned, blended, and processed fiber 96 is pneumatically transported away from the MTM. It will be appreciated that additional fiber property measurements may be advantageously made with electro-optical means. These fiber parameters include the lint feed rate, the fiber diameter distribution, which relates to maturity and fineness, and the length distribution, which is an important parameter determining the yarn properties, especially strength. From the length distribution one may determine the conventional specifications such as 21/2% span length, upper-half mean, or short fiber content of the fibers. Short fiber content, for example, the percentage weight below 1/2" in fiber length, is of significant importance currently because of the excessive ginning required to clean cotton harvested by the stripper method. This equipment entrains much more foreign matter into the seed cotton than prior harvesting methods. It is believed that increasing short fiber content is currently resulting in poorer quality yarn and less economical preparation thereof.
It will be appreciated that still other fiber parameters may obviously be made electro-optically in the state illustrated in FIG. 1 or perhaps in a condensed state. These include color and nep content. (Neps are small ball-like entanglements of fiber that ultimately appear as yarn or cloth imperfections.) The pneumatic transported state of FIG. 1 is preferentially ideal for identification of neps.
In summary, the more conceptual methods and apparatus of FIGS. 1-3 and the preferred embodiments of FIGS. 4-6 teach a new method for removing foreign matter from lint. It is emphasized again that the teachings of this invention or extensions thereof are equally applicable to measurements of foreign matter and to its removal for improved processing purposes. It is envisioned for the latter application that higher speed, more efficient, and less damaging lint cleaning and other processing machinery can now evolve based on the principles of these teachings.
While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention. | Apparatus and methods for controlled application of aeromechanical and electrodynamic release and separation forces to foreign particulate matter in fiber materials are disclosed. A number of elements are employed in various combinations. One important element is a perforated, pinned cylinder which facilitates foreign particulate matter removal and microdust classification and use of conditioned and controlled airflow for optimum fiber processing and foreign matter removal. Another important element is a counterflow slot. Other important aspects are air blast cleaning of a tenuous mat held onto a preforated cylinder; unidirectional and pulsating airflows to cause repeated engagement of fibers with static cleaning pins and to release additional dust; application of electrostatic release forces to particles bound onto the fiber; and the processing of fiber in properly conditioned inlet air to the machine, as opposed to ambient air. These methods and apparatus enable the design of precise and accurate measurement apparatus for foreign matter in fiber samples. They further provide effective cleaning, blending, and preprocessing of textile fibers for improved measurements of fiber properties. Still further, the invention may be applied to improved fiber cleaning equipment in gins or in textile mills. The invention ultimately permits a simplified spinning apparatus whose input is tufts and whose output is spun yarn. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0093677 filed on Aug. 7, 2013, and 10-2012-0126298 filed on Nov. 8, 2012 in the Korean Intellectual Property Office the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a flow switch, and an operating method thereof, and more particularly, to a flow switch for providing network virtualization, in which a quality of service (QoS) for a packet for each virtual machine is easily secured through flow information extracted from each of a plurality of packets when the plurality of packets generated by a plurality of virtual machines is input in a server virtualization environment, and an operating method thereof.
BACKGROUND ART
[0003] Recently, as a semiconductor technology is developed, performance of a computer processor is highly improved, and as a multi core processor technology is developed, the amount of operations simultaneously operable in one computer server is remarkably increased. A minimum of several tens to a maximum of several hundreds of computer servers are installed in a private data center of a business or financial field to provide services in the business or financial field (business finance, finance, stocks, and the like). In an Internet data center (IDC), several hundreds or several thousands of computer servers are installed at one place, so that various and stable services (a web server, a mail server, a file server, a video server, and a cloud server, and the like) are provided to different service users. In this environment, a decrease in costs and simplification of a management by integrally operating the server is demanded, and a necessity to control a large-sized multi processor, such as a server storage place or a render farm, and cluster equipment is also raised. Demands for security, reliability, and independency of equipment have also increased. Especially, an execution of an application program dependent on a specific operating system in a different hardware or operating system environment is required.
[0004] In order to meet the requirements, a concept of server virtualization emerges. In the server virtualization environment, one or more different virtual machines (several, several tens, or several hundreds of virtual machines) may exist in one computer server. There is a hypervisor (or a virtual machine monitor (VMM)) sharing and simultaneously executing hardware (a CPU, a memory, a storage, a network interface, and the like) resources of a computer server in which several (several tens or several hundreds of) different virtual machines are virtualized. The hypervisor performs functions, such as a generation of a virtual machine within a server, a removal of a virtual machine, and a management of resources of virtual machines. The hypervisor enables the virtual machines to share a network and a storage. In a case of the storage, when the hypervisor is set so that each virtual machine uses a storage of a logically or physically divided region, the virtual machines may share the entire storage without interfering each other. However, in a case of the network, several virtual machines (several tens or several hundreds of virtual machines) installed in one computer server generally share one or more network devices. When one or more network devices are shared by one or more virtual machines, one or more virtual machines need to be provided so that the virtual machines share a network without interfering each other in a network level for each virtual machine.
[0005] Researches on a network virtualization technology for solving the aforementioned problems have been recently conducted.
SUMMARY OF THE INVENTION
[0006] The present invention has been made in an effort to provide a flow switch capable of easily providing a service at a stable speed even though the number of virtual machines connected to a hypervisor is increased by extracting flow information about each of a plurality of packets and providing network virtualization, in which a quality of service is secured according to QoS information set by using the flow information and information about a virtual machine extracting the flow information, when the plurality of packets generated by the plurality of virtual machines in a server virtualization environment is transmitted through the hypervisor, and an operating method thereof.
[0007] An exemplary embodiment of the present invention provides a flow switch including: a virtual flow recognition switch unit configured to receive a plurality of packets transmitted from hypervisors through a network interface, and process the plurality of packets; a flow determination unit configured to extract flow information corresponding to each of the plurality of packets, and determine whether there is stored previous flow information matched with the flow information; and a packet processing control unit configured to check whether the flow information is included in predetermined QoS limitation information when there is the previous flow information, control the virtual flow recognition switch unit so that a corresponding packet, from which the flow information is extracted, is processed by applying previous QoS policy information matched with the previous flow information when the flow information is included in the QoS limitation information, and control the virtual flow recognition switch unit so that the corresponding packet is processed without applying the previous QoS policy information when the flow information is not included in the QoS limitation information.
[0008] Another exemplary embodiment of the present invention provides a method of operating a flow switch, including: extracting flow information corresponding to each of a plurality of packets when the plurality of packets is transmitted from hypervisors through a network interface; determining whether there is stored previous flow information matched with the flow information; checking whether the flow information is included in predetermined QoS limitation information when there is the previous flow information matched with the flow information; and processing a corresponding packet, from which the flow information is extracted, by applying previous QoS policy information matched with the previous flow information when the flow information is included in predetermined QoS limitation information, and processing the corresponding packet without applying the previous QoS policy information when the flow information is not included in the QoS limitation information.
[0009] The operation method of the flow switch according to the exemplary embodiment has advantages in that it is possible to provide a service of which a quality of service (QoS) for a packet and a virtual machine is secured, and prevent deterioration of a service quality for another packet and another virtual machine by extracting flow information of each of a plurality of packets transmitted from hypervisors and using the flow information and information about a virtual machine generating the packet from which the flow information is extracted.
[0010] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a system diagram schematically illustrating a network system including a flow switch according to an exemplary embodiment.
[0012] FIG. 2 is a control block diagram illustrating a control configuration of the flow switch illustrated in FIG. 1 .
[0013] FIG. 3 is a flowchart illustrating an operating method of the flow switch according to the exemplary embodiment.
[0014] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0015] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
[0016] Hereinafter, an exemplary embodiment according to the present invention will be described in detail with reference to the accompanying drawings. First, in denoting reference numerals to constitutional elements of respective drawings, the same elements will be designated by the same reference numerals although they are shown in different drawings. In the following description of the present invention, a detailed description of known configurations or functions incorporated herein will be omitted when it is determined that the detailed description may make the subject matter of the present invention unclear. An exemplary embodiment of the present invention will be described below, but the technical spirit of the present invention is not limited thereto and may be modified and variously implemented by those skilled in the art.
[0017] FIG. 1 is a system diagram schematically illustrating a network system including a flow switch according to an exemplary embodiment.
[0018] Referring to FIG. 1 , a network system may include first to fourth servers 110 to 140 , and first and second flow switches 210 and 220 .
[0019] Here, each of the first to fourth servers 110 to 140 may include first and second virtual machines 112 , 114 , 122 , 124 , 132 , 134 , 142 , and 144 , and hypervisors 116 , 126 , 136 , and 146 .
[0020] In the exemplary embodiment, it is represented that each of the first to fourth servers 110 to 140 equally includes two virtual machines, but the number of virtual machines is not limited.
[0021] In the exemplary embodiment, it is described that the hypervisors 116 , 126 , 136 , and 146 perform the same configuration and function, but the hypervisors are not limited thereto.
[0022] In the exemplary embodiment, the first server 110 will be mainly described, and the second and fourth servers 120 to 140 may perform the similar configuration and function to that of the first server 110 , but the servers are not limited thereto.
[0023] The first server 110 includes a first virtual machine 112 generating a first packet, a second virtual machine 114 generating a second packet, and a hypervisor 116 receiving the first and second packets generated by the first and second virtual machines 112 and 114 and transmitting the received first and second packets to the first flow switch 210 connected to a network interface 170 .
[0024] Here, the first and second virtual machines 112 and 114 may be operating systems (OS), for example, LINUX, NetBSD, FreeBSD, Solaris, and Windows, operated in logical hardware (a virtual CPU, a virtual memory, a virtual storage, and a virtual network interface) provided by the hypervisor 116 .
[0025] The first and second virtual machines 112 and 114 generate the first and second packets according to a demanded service, for example, a web server, a mail server, a file server, a video server, and a cloud server, business finance, finance, and stocks, and the first and second packets include first and second flow information representing the demands for different qualities of service (QoS) according to the demanded services.
[0026] The hypervisor 116 virtualizes physical hardware, for example, a CPU, a memory, a storage, and a network interface, and provides the virtualized physical hardware to the first and second virtual machines 112 and 114 .
[0027] The hypervisor 116 performs a function of a generation, a removal, and a management of resources of the first and second virtual machines 112 and 114 , and transmits the first and second packets to the first flow switch 210 through the network interface 170 .
[0028] In the exemplary embodiment, it is described that the first and second flow switches 210 and 220 perform the same configuration and function, but the first and second flow switches 210 and 220 are not limited thereto, and the configurations and the functions may be different from each other.
[0029] The first and second flow switches 210 and 220 may communicate with each other through the Internet or Intranet, but are not limited thereto.
[0030] The first flow switch 210 receives the first and second packets transmitted through the network interface 170 connected with the first and second servers 110 and 120 .
[0031] In this case, the first flow switch 210 receives the first and second packets transmitted from the hypervisor 150 , extracts the first flow information from the first packet, and extracts the second flow information from the second packet.
[0032] The first flow switch 210 checks whether first and second previous flow information corresponding to the first and second flow information, respectively, is stored in a flow information table stored based on the first and second flow information.
[0033] Then, when the first and second previous flow information corresponding to the first and second flow information, respectively, exists, the first flow switch 210 may process the first and second packets according to first and second previous QoS policy information corresponding to the first and second previous flow information, respectively.
[0034] Here, when the first and second previous flow information exists, the first flow switch 210 may check whether the first and second previous flow information is included in QoS limitation information set for the first and second packets before the first and second previous QoS policy information is applied, and determine whether to apply the first and second previous QoS policy information.
[0035] This will be described in detail with reference to FIG. 2 below.
[0036] When the first and second previous flow information corresponding to at least one of the first and second flow information does not exist in the flow information table, the first flow switch 210 generates new QoS policy information according to a QoS generation policy set for at least one of the first and second flow information, and processes at least one of the first and second flow information according to the QoS policy information.
[0037] Here, the first flow switch 210 may be connected with the second flow switch 220 through the Internet or the Intranet, to receive services for the first and second packets, or provide a service for another packet.
[0038] FIG. 2 is a control block diagram illustrating a control configuration of the flow switch illustrated in FIG. 1 .
[0039] Referring to FIG. 2 , the flow switch 210 includes a virtual flow recognition switch 212 , a flow determination unit 214 , and a packet processing control unit 216 .
[0040] The virtual flow recognition switch 212 receives the first and second packets transmitted from the hypervisor 116 included in the first server 110 connected through the network interface 170 , and transfers the received first and second packets to another virtual flow recognition switch through the Internet or the Intranet according to a control of the packet processing control unit 216 to provide or receive a service.
[0041] Here, the virtual flow recognition switch 212 may be a logically virtual switch or a physical switch, but is not limited thereto.
[0042] The flow determination unit 214 extracts the first flow information from the first packet received from the virtual flow recognition switch 212 , extracts the second flow information from the second packet, and checks whether the first and second previous flow information corresponding to the first and second flow information is stored in a stored previous flow information list.
[0043] Here, each of the first and second flow information may include at last one of an IP source address, an IP destination address, a protocol number, source transport information, and destination transport information included in the first and second packets.
[0044] The packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first and second packets are processed according to a result of a determination of the flow determination unit 214 .
[0045] That is, when there is no first and second previous flow information matched with the first and second flow information, respectively, as a result of the determination of the flow determination unit 214 , the packet processing control unit 216 generates the first and second QoS policy information according to the QoS generation policy set based on each of the first and second flow information, transmits the first and second QoS policy information to the virtual flow recognition switch 212 , and controls the virtual flow recognition switch 212 so that the first and second packets are processed.
[0046] In this case, the QoS generation policy may include at least one of the type of services, the amount of bandwidth used, and predetermined user demands based on the first and second flow information.
[0047] When there is the first previous flow information matched with the first flow information, and there is no second previous flow information matched with the second flow information as the result of the determination of the flow determination unit 214 , the packet processing controller 216 generates the second QoS policy information based on the second flow information and transmits the generated second QoS policy information to the virtual flow recognition switch 212 as described above.
[0048] In this case, in a case where there is the first previous flow information matched with the first flow information, the packet processing control unit 216 checks whether the first flow information is included in the predetermined QoS limitation information in order to apply first previous QoS policy information corresponding to the first previous flow information.
[0049] That is, in a case where there is the first previous flow information, the packet processing control unit 216 calculates the total amount of bandwidths used for the first and second packets, and the amount of first individual bandwidth used for the first packet.
[0050] Then, the packet processing control unit 216 compares the total amount of bandwidths used and a port bandwidth of the network interface 170 included in the QoS limitation information, and when the total amount of bandwidths used is equal to or smaller than the port bandwidth, the packet processing control unit 216 controls the virtual flow recognition switch unit 2112 so that the first packet is processed without applying the first previous QoS information.
[0051] When the total amount of bandwidths used is larger than the port bandwidth, the packet processing control unit 216 re-checks whether the amount of total bandwidths used is included in the amount of first individual bandwidth used and an individual bandwidth included in the QoS limitation information, and when the amount of first individual bandwidth used is equal to or smaller than the individual bandwidth, the packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first packet is processed without applying the first previous QoS information.
[0052] When the amount of first individual bandwidth used is larger than the individual bandwidth, the packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first packet having the amount of first individual bandwidth used is processed by applying the first previous QoS policy information.
[0053] In the exemplary embodiment, the first and second flow information of the first and second packets contains information about the first and second virtual machines 112 and 114 generating the first and second packets, and the flow information table may include at least one of a virtual machine information list and a flow information list.
[0054] Accordingly, in a case where the packet processing control unit 216 stores the first and second flow information in the flow information table, the packet processing control unit 216 may make a control so that the first and second flow information is divided and stored in at least one of the virtual machine information list and the flow information list.
[0055] FIG. 3 is a flowchart illustrating an operating method of the flow switch according to the exemplary embodiment.
[0056] Referring to FIG. 3 , when first and second packets 112 and 114 are transmitted from the hypervisors 116 and 126 through the network interface 170 , the flow switch 210 extracts first and second flow information corresponding to the first and second packets 112 and 114 , respectively (S 110 ).
[0057] That is, the virtual flow recognition switch 212 receives the first and second packets transmitted from the hypervisor 116 included in the first server 110 connected through the network interface 170 , and transfers the received first and second packets to another virtual flow recognition switch through the Internet or the Intranet according to a control of the packet processing control unit 216 to provide or receive a service.
[0058] The flow determination unit 214 extracts the first flow information from the first packet received by the virtual flow recognition switch 212 and the second flow information from the second packet.
[0059] After step S 110 , the flow switch 210 determines whether the there is stored first and second previous flow information matched with the first and second flow information, respectively (S 120 ), and when there is not first and second previous flow information or the first previous flow information, the flow switch 210 generates each of first and second QoS policy information according to QoS generation policy corresponding to each of the first and second flow information, or generates first QoS policy information according to a QoS generation policy corresponding to the first flow information (S 130 ), and processes the first and second packets according to the first and second QoS policy information or processes the first packet according to the first QoS policy information (S 140 ).
[0060] That is, when there is no stored first and second previous flow information matched with the first and second flow information, respectively, or there is no first previous flow information matched with the first flow information among the first and second flow information as a result of the determination of the flow determination unit 214 , the packet processing control unit 216 generates the first and second QoS policy information according to a QoS generation policy set based on each of the first and second flow information, or generates the first QoS policy information according to a QoS generation policy set based on the first flow information.
[0061] Then, the packet processing control unit 216 transmits the first and second QoS policy information or the first QoS policy information to the virtual flow recognition switch 212 , and controls the virtual flow recognition switch 212 so that the first and second packets or the first packet is processed.
[0062] When there is the first and second previous flow information or there is only the second previous flow information as the result of the determination of step S 120 , the flow switch 210 calculates the total amount of bandwidths used for the first and second packets and the amounts of first and second individual bandwidths used for the respective first and second packets (S 150 ).
[0063] That is, when there is the stored first and second previous flow information matched with the first and second flow information, respectively or there is only the second previous flow information matched with the second flow information among the first and second flow information as a result of the determination of the flow determination unit 214 , the packet processing control unit 216 calculates the total amount of bandwidths used for the first and second packets, and the amounts of first and second individual bandwidths used for the respective first and second packets.
[0064] The flow switch 210 compares whether the total amount of bandwidths used calculated in step S 150 is larger than a port bandwidth included in predetermined QoS limitation information (S 160 ), when the total amount of bandwidths used is smaller than the port bandwidth, the flow switch 210 controls so as to process the first and second packets or the second packet without applying the first and second previous QoS policy information or the second previous QoS policy information (S 170 ).
[0065] That is, when the total amount of bandwidths used is smaller than the port bandwidth included in the predetermined QoS limitation information, for example, a bandwidth of the network interface 170 , the packet processing control unit 216 controls so as to process the first and second packets or the second packet without applying the first and second previous QoS policy information or the second previous QoS policy information.
[0066] When the total amount of bandwidths used is larger than the port bandwidth in step S 160 , the flow switch 210 compares the amounts of first and second individual bandwidths used and first and second individual bandwidths included in the QoS limitation information and corresponding to the amounts of respective first and second individual bandwidths used, and compares whether the amounts of first and second individual bandwidths used are larger than the first and second individual bandwidths, respectively, or whether the amount of second individual bandwidth used is larger than the second individual bandwidth (S 180 ). When the amounts of first and second individual bandwidths used are smaller than the first and second individual bandwidths, respectively, or when the amount of second individual bandwidth used is smaller than the second individual bandwidth, the flow switch 210 controls the virtual flow recognition switch 212 so that the first and second packets are processed without applying the first and second previous QoS policy information (S 190 ).
[0067] That is, the packet processing control unit 216 compares the first and second individual bandwidths matched with the amounts of first and second individual bandwidths used, respectively, and compares whether the amount of first individual bandwidth used is larger than the first individual bandwidth, or whether the amount of second individual bandwidth used is larger than the second individual bandwidth.
[0068] Here, when the amount of first individual bandwidth used is smaller than the first individual bandwidth, and the amount of second individual bandwidth used is smaller than the second individual bandwidth used, the packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first and second packets are processed without applying the first and second previous QoS policy information.
[0069] When at least one of the amounts of first and second individual bandwidths used is larger than the first and second individual bandwidths in step S 180 , the flow switch 210 controls the virtual flow recognition switch 212 so that the first and second packets are processed by applying the first and second previous QoS policy information corresponding to at least one of the corresponding first and second packets (S 200 ).
[0070] That is, when both the amounts of first and second individual bandwidths used are larger than the first and second individual bandwidths, the packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first and second packets are processed by applying the first and second previous QoS policy information, and when the amount of first individual bandwidth used is larger than the first individual bandwidth or the amount of second individual bandwidth used is larger than the second individual bandwidth, the packet processing control unit 216 controls the virtual flow recognition switch 212 so that the first and second packets are processed by applying the corresponding first and second previous QoS policy information.
[0071] Even if it is described that all of constituent elements constituting the aforementioned exemplary embodiment of the present invention are coupled as a single unit or coupled to be operated as a single unit, the present invention is not necessarily limited to the exemplary embodiment. That is, among all of the constituent elements, one or more constituent elements may be selectively coupled to be operated within the scope of the object of the present invention. Although each of all of the constituent elements may be implemented as an independent hardware, some or all of the constituent elements may be selectively combined with each other, so that they can be implemented as a computer program having a program module for executing some or all of the functions combined in one or more hardware.
[0072] All terms used herein including technical or scientific terms have the same meanings as meanings which are generally understood by those skilled in the art unless they are differently defined in the detailed description. Terms generally used, such as terms defined in a dictionary, shall be construed that they have construed as having meanings matching those in the context of a related art, and shall not be construed in ideal or excessively formal meanings unless they are clearly defined in the present application.
[0073] As described above, the exemplary embodiments have been described and illustrated in the drawings and the specification. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. | An exemplary embodiment of the present invention provides a flow switch, and an operating method thereof, and more particularly, to a flow switch for providing network virtualization, in which a quality of service (QoS) for a packet for each virtual machine is easily secured through flow information extracted from each of a plurality of packets when the plurality of packets generated by a plurality of virtual machines is input in a server virtualization environment, and an operating method thereof. | 7 |
TECHNICAL FIELD
[0001] The invention generally relates to a system for providing a joint along adjacent joint edges of two building panels, especially floor panels.
[0002] More specifically, the joint is of the type where the adjacent joint edges together form a first mechanical connection locking the joint edges to each other in a first direction at right angles to the principal plane of the panels, and where a locking device forms a second mechanical connection locking the panels to each other in a second direction parallel to the principal plane and at right angles to the joint edges, the locking device comprising a locking groove which extends parallel to and spaced from the joint edge of one of the panels, and said locking groove being open at the rear side of this one panel.
[0003] The invention is especially well suited for use in joining floor panels, especially thin laminated floors. Thus, the following description of the prior art and of the objects and features of the invention will be focused on this field of use. It should however be emphasised that the invention is useful also for joining ordinary wooden floors as well as other types of building panels, such as wall panels and roof slabs.
BACKGROUND OF THE INVENTION
[0004] A joint of the aforementioned type is known e.g. from SE 450,141. The first mechanical connection is achieved by means of joint edges having tongues and grooves. The locking device for the second mechanical connection comprises two oblique locking grooves, one in the rear side of each panel, and a plurality of spaced-apart spring clips which are distributed along the joint and the legs of which are pressed into the grooves, and which are biased so as to tightly clamp the floor panels together. Such a joining technique is especially useful for joining thick floor panels to form surfaces of a considerable expanse.
[0005] Thin floor panels of a thickness of about 7-10 mm, especially laminated floors, have in a short time taken a substantial share of the market. All thin floor panels employed are laid as “floating floors” without being attached to the supporting structure. As a rule, the dimension of the floor panels is 200×1200 mm, and their long and short sides are formed with tongues and grooves. Traditionally, the floor is assembled by applying glue in the groove and forcing the floor panels together. The tongue is then glued in the groove of the other panel. As a rule, a laminated floor consists of an upper decorative wear layer of laminate having a thickness of about 1 mm, an intermediate core of particle board or other board, and a base layer to balance the construction. The core has essentially poorer properties than the laminate, e.g. in respect of hardness and water resistance, but it is nonetheless needed primarily for providing a groove and tongue for assemblage. This means that the overall thickness must be at least about 7 mm. These known laminated floors using glued tongue-and-groove joints however suffer from several inconveniences.
[0006] First, the requirement of an overall thickness of at least about 7 mm entails an undesirable restraint in connection with the laying of the floor, since it is easier to cope with low thresholds when using thin floor panels, and doors must often be adjusted in height to come clear of the floor laid. Moreover, manufacturing costs are directly linked with the consumption of material.
[0007] Second, the core must be made of moisture-absorbent material to permit using water-based glues when laying the floor. Therefore, it is not possible to make the floors thinner using so-called compact laminate, because of the absence of suitable gluing methods for such nonmoisture-absorbent core materials.
[0008] Third, since the laminate layer of the laminated floors is highly wear-resistant, tool wear is a major problem when working the surface in connection with the formation of the tongue.
[0009] Fourth, the strength of the joint, based on a glued tongue-and-groove connection, is restricted by the properties of the core and of the glue as well as by the depth and height of the groove. The laying quality is entirely dependent on the gluing. In the event of poor gluing, the joint will open as a result of the tensile stresses which occur e.g. in connection with a change in air humidity.
[0010] Fifth, laying a floor with glued tongue-and-groove joints is time-consuming, in that glue must be applied to every panel on both the long and short sides thereof.
[0011] Sixth, it is not possible to disassemble a glued floor once laid, without having to break up the joints. Floor panels that have been taken up cannot therefore be used again. This is a drawback particularly in rental houses where the flat concerned must be put back into the initial state of occupancy. Nor can damaged or worn-out panels be replaced without extensive efforts, which would be particularly desirable on public premises and other areas where parts of the floor are subjected to great wear.
[0012] Seventh, known laminated floors are not suited for such use as involves a considerable risk of moisture penetrating down into the moisture-sensitive core.
[0013] Eighth, present-day hard, floating floors require, prior to laying the floor panels on hard subfloors, the laying of a separate underlay of floor board, felt, foam or the like, which is to damp impact sounds and to make the floor more pleasant to walk on. The placement of the underlay is a complicated operation, since the underlay must be placed in edge-to-edge fashion. Different underlays affect the properties of the floor.
[0014] There is thus a strongly-felt need to overcome the above-mentioned drawbacks of the prior art. It is however not possible simply to use the known joining technique with glued tongues and grooves for very thin floors, e.g. with floor thicknesses of about 3 mm, since a joint based on a tongue-and-groove connection would not be sufficiently strong and practically impossible to produce for such thin floors. Nor are any other known joining techniques usable for such thin floors. Another reason why the making of thin floors from e.g. compact laminate involves problems is the thickness tolerances of the panels, being about 0.2-0.3 mm for a panel thickness of about 3 mm. A 3-mm compact laminate panel having such a thickness tolerance would have, if ground to uniform thickness on its rear side, an unsymmetrical design, entailing the risk of bulging. Moreover, if the panels have different thicknesses, this also means that the joint will be subjected to excessive load.
[0015] Nor is it possible to overcome the above-mentioned problems by using double-adhesive tape or the like on the undersides of the panels, since such a connection catches directly and does not allow for subsequent adjustment of the panels as is the case with ordinary gluing.
[0016] Using U-shaped clips of the type disclosed in the above-mentioned SE 450,141, or similar techniques, to overcome the drawbacks discussed above is no viable alternative either. Especially, biased clips of this type cannot be used for joining panels of such a small thickness as 3 mm. Normally, it is not possible to disassemble the floor panels without having access to their undersides. This known technology relying on clips suffers from the additional drawbacks:
[0017] Subsequent adjustment of -the panels in their longitudinal direction is a complicated operation in connection with laying, since the clips urge the panels tightly against each other.
[0018] Floor laying using clips is time-consuming.
[0019] This technique is usable only in those cases where the floor panels are resting on underlying joists with the clips placed therebetween. For thin floors to be laid on a continuous, flat supporting structure, such clips cannot be used.
[0020] The floor panels can be joined together only at their long sides. No clip connection is provided on the short sides.
TECHNICAL PROBLEMS AND OBJECTS OF THE INVENTION
[0021] A main object of the invention therefore is to provide a system for joining together building panels, especially floor panels for hard, floating floors, which allows using floor panels of a smaller overall thickness than present-day floor panels.
[0022] A particular object of the invention is to provide a panel-joining system which
[0023] makes it possible in a simple, cheap and rational way to provide a joint between floor panels without requiring the use of glue, especially a joint based primarily only on mechanical connections between the panels;
[0024] can be used for joining floor panels which have a smaller thickness than present-day laminated floors and which have, because of the use of a different core material, superior properties than present-day floors even at a thickness of 3 mm;
[0025] makes it possible between thin floor panels to provide a joint that eliminates any unevennesses in the joint because of thickness tolerances of the panels;
[0026] allows joining all the edges of the panels;
[0027] reduces tool wear when manufacturing floor panels with hard surface layers;
[0028] allows repeated disassembly and reassembly of a floor previously laid, without causing damage to the panels, while ensuring high laying quality;
[0029] makes it possible to provide moisture-proof floors;
[0030] makes it possible to obviate the need of accurate, separate placement of an underlay before laying the floor panels; and
[0031] considerably cuts the time for joining the panels.
[0032] These and other objects of the invention are achieved by means of a panel-joining system having the features recited in the appended claims.
[0033] Thus, the invention provides a system for making a joint along adjacent joint edges of two building panels, especially floor panels, in which joint:
[0034] the adjacent joint edges together form a first mechanical connection locking the joint edges to each other in a first direction at right angles to the principal plane of the panels, and
[0035] a locking device arranged on the rear side of the panels forms a second mechanical connection locking the panels to each other in a second direction parallel to the principal plane and at right angles to the joint edges, said locking device comprising a locking groove which extends parallel to and spaced from the joint edge of one of said panels, termed groove panel, and which is open at the rear side of the groove panel, said system being characterised in
[0036] that the locking device further comprises a strip integrated with the other of said panels, termed strip panel, said strip extending throughout substantially the entire length of the joint edge of the strip panel and being provided with a locking element projecting from the strip, such that when the panels are joined together, the strip projects on the rear side of the groove panel with its locking element received in the locking groove of the groove panel,
[0037] that the panels, when joined together, can occupy a relative position in said second direction where a play exists between the locking groove and a locking surface on the locking element that is facing the joint edges and is operative in said second mechanical connection,
[0038] that the first and the second mechanical connection both allow mutual displacement of the panels in the direction of the joint edges, and
[0039] that the second mechanical connection is so conceived as to allow the locking element to leave the locking groove if the groove panel is turned about its joint edge angularly away from the strip.
[0040] The term “rear side” as used above should be considered to comprise any side of the panel located behind/underneath the front side of the panel. The opening plane of the locking groove of the groove panel can thus be located at a distance from the rear surface of the panel resting on the supporting structure. Moreover, the strip, which in the invention extends throughout substantially the entire length of the joint edge of the strip panel, should be considered to encompass both the case where the strip is a continuous, uninterrupted element, and the case where the “strip” consists in its longitudinal direction of several parts, together covering the main portion of the joint edge.
[0041] It should also be noted (i) that it is the first and the second mechanical connection as such that permit mutual displacement of the panels in the direction of the joint edges, and that (ii) it is the second mechanical connection as such that permits the locking element to leave the locking groove if the groove panel is turned about its joint edge angularly away from the strip. Within the scope of the invention, there may thus exist means, such as glue and mechanical devices, that can counteract or prevent such displacement and/or upward angling.
[0042] The system according to the invention makes it possible to provide concealed, precise locking of both the short and long sides of the panels in hard, thin floors. The floor panels can be quickly and conveniently disassembled in the reverse order of laying without any risk of damage to the panels, ensuring at the same time a high laying quality. The panels can be assembled and disassembled much faster than in present-day systems, and any damaged or worn-out panels can be replaced by taking up and re-laying parts of the floor.
[0043] According to an especially preferred embodiment of the invention, a system is provided which permits precise joining of thin floor panels having, for example, a thickness of the order of 3 mm and which at the same time provides a tolerance-independent smooth top face at the joint. To this end, the strip is mounted in an equalising groove which, is countersunk in the rear side of the strip panel and which exhibits an exact, predetermined distance from its bottom to the front side of the strip panel. The part of the strip projecting behind the groove panel engages a corresponding equalising groove, which is countersunk in the rear side of the groove panel and which exhibits the same exact, predetermined distance from its bottom to the front side of the groove panel. The thickness of the strip then is at least so great that the rear side of the strip is flush with, and preferably projects slightly below the rear side of the panels. In this embodiment, the panels will always rest, in the joint, with their equalising grooves on a strip. This levels out the tolerance and imparts the necessary strength to the joint. The strip transmits horizontal and upwardly-directed forces to the panels and downwardly-directed forces to the existing subfloor.
[0044] Preferably, the strip may consist of a material which is flexible, resilient and strong, and can be sawn. A preferred strip material is sheet aluminium. In an aluminium strip, sufficient strength can be achieved with a strip thickness of the order of 0.5 mm.
[0045] In order to permit taking up previously laid, joined floor panels in a simple way, a preferred embodiment of the invention is characterised in that when the groove panel is pressed against the strip panel in the second direction and is turned anglularly away from the strip, the maximum distance between the axis of rotation of the groove panel and the locking surface of the locking groove closest to the joint edges is such that the locking element can leave the locking groove without contacting the locking surface of the locking groove. Such a disassembly can be achieved even if the aforementioned play between the locking groove and the locking surface is not greater than 0.2 mm.
[0046] According to the invention, the locking surface of the locking element is able to provide a sufficient locking function even with very small heights of the locking surface. Efficient locking of 3-mm floor panels can be achieved with a locking surface that is as low as 2 mm. Even a 0.5-mm-high locking surface may provide sufficient locking. The term “locking surface” as used herein relates to the part of the locking element engaging the locking groove to form the second mechanical connection.
[0047] For optimal function of the invention, the strip and the locking element should be formed on the strip panel with high precision. Especially, the locking surface of the locking element should be located at an exact distance from the joint edge of the strip panel.
[0048] Furthermore, the extent of the engagement in the floor panels should be minimised, since it reduces the floor strength.
[0049] By known manufacturing methods, it is possible to produce a strip with a locking pin, for example by extruding aluminium or plastics into a suitable section, which is thereafter glued to the floor panel or is inserted in special grooves. These and all other traditional methods do however not ensure optimum function and an optimum level of economy. To produce the joint system according to the invention, the strip is suitably formed from sheet aluminium, and is mechanically fixed to the strip panel.
[0050] The laying of the panels can be performed by first placing the strip panel on the subfloor and then moving the groove panel with its long side up to the long side of the strip panel, at an angle between the principal plane of the groove panel and the subfloor. When the joint edges have been brought into engagement with each other to form the first mechanical connection, the groove panel is angled down so as to accommodate the locking element in the locking groove.
[0051] Laying can also be performed by first placing both -the strip panel and the groove panel flat on the subfloor and then joining the panels parallel to their principal planes while bending the strip downwards until the locking element snaps up into the locking groove. This laying technique enables in particular mechanical locking of both the short and long sides of the floor panels. For example, the long sides can be joined together by using the first laying technique with downward angling of the groove panel, while the short sides are subsequently joined together by displacing the groove panel in its longitudinal direction until its short side is pressed on and locked to the short side of an adjacent panel in the same row.
[0052] In connection with their manufacture, the floor D panels can be provided with an underlay of e.g. floor board, foam or felt. The underlay should preferably cover the strip such that the joint between the underlays is offset in relation to the joint between the floor panels.
[0053] The above and other features and advantages of the invention will appear from the appended claims and the following description of embodiments of the invention.
[0054] The invention will now be described in more detail hereinbelow with reference to the accompanying drawing Figures.
DESCRIPTION OF DRAWING FIGURES
[0055] [0055]FIGS. 1 a and 1 b schematically show in two stages how two floor panels of different thickness are joined together in floating fashion according to a first embodiment of the invention.
[0056] [0056]FIGS. 2 a - c show in three stages a method for mechanically joining two floor panels according to a second embodiment of the invention.
[0057] [0057]FIGS. 3 a - c show in three stages another method for mechanically joining the floor panels of FIGS. 2 a - c.
[0058] [0058]FIGS. 4 a and 4 b show a floor panel according to FIGS. 2 a - c as seen from below and from above, respectively.
[0059] [0059]FIG. 5 illustrates in perspective a method for laying and joining floor panels according to a third embodiment of the invention.
[0060] [0060]FIG. 6 shows in perspective and from below a first variant for mounting a strip on a floor panel.
[0061] [0061]FIG. 7 shows in section a second variant for mounting a strip on a floor panel.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0062] [0062]FIGS. 1 a and 1 b , to which reference is now made, illustrate a first floor panel 1 , hereinafter termed strip panel, and a second floor panel 2 , hereinafter termed groove panel. The terms “strip panel” and “groove panel” are merely intended to facilitate the description of the invention, the panels 1 , 2 normally being identical in practice. The panels 1 and 2 may be made from compact laminate and may have a thickness of about 3 mm with a thickness tolerance of about ±0.2 mm. Considering this thickness tolerance, the panels 1 , 2 are illustrated with different thicknesses (FIG. 1 b ), the strip panel 1 having a maximum thickness (3.2 mm) and the groove panel 2 having a minimum thickness (2.8 mm).
[0063] To enable mechanical joining of the panels 1 , 2 at opposing joint edges, generally designated 3 and 4 , respectively, the panels are provided with grooves and strips as described in the following.
[0064] Reference is now made primarily to FIGS. 1 a and 1 b , and secondly to FIGS. 4 a and 4 b showing the basic design of the floor panels from below and from above, respectively.
[0065] From the joint edge 3 of the strip panel 1 , i.e. the one long side, projects horizontally a flat strip 6 mounted at the factory on the underside of the strip panel 1 and extending throughout the entire joint edge 3 . The strip 6 , which is made of flexible, resilient sheet aluminium, can be fixed mechanically, by means of glue or in any other suitable way. In FIGS. 1 a and 1 b , the strip 6 is glued, while in FIGS. 4 a and 4 b it is mounted by means of a mechanical connection, which will be described in more detail hereinbelow.
[0066] Other strip materials can be used, such as sheets of other metals, as well as aluminium or plastics sections. Alternatively, the strip 6 may be integrally formed with the strip panel 1 . At any rate, the strip 6 should be integrated with the strip panel 1 , i.e. it should not be mounted on the strip panel 1 in connection with laying. As a non-restrictive example, the strip 6 may have a width of about 30 mm and a thickness of about 0.5 mm.
[0067] As appears from FIGS. 4 a and 4 b , a similar, although shorter strip 6 ′ is provided also at one short side 3 ′ of the strip panel 1 . The shorter strip 6 ′ does however not extend throughout the entire short side 3 ′ but is otherwise identical with the strip 6 and, therefore, is not described in more detail here.
[0068] The edge of the strip 6 facing away from the joint edge 3 is formed with a locking element 8 extended throughout the entire strip 6 . The locking element 8 has a locking surface 10 facing the joint edge 3 and having a height of e.g. 0.5 mm. The locking element 8 is so designed that when the floor is being laid and the strip panel, 2 of FIG. 1 a is pressed with its joint edge 4 against the joint edge 3 of the strip panel 1 and is angled down against the subfloor 12 according to FIG. 1 b , it enters a locking groove 14 formed in the underside 16 of the groove panel 2 and extending parallel to and spaced from the joint edge 4 . In FIG. 1 b , the locking element 8 and the locking groove 14 together form a mechanical connection locking the panels 1 , 2 to each other in the direction designated D 2 . More specifically, the locking surface 10 of the locking element 8 serves as a stop with respect to the surface of the locking groove 14 closest to the joint edge 4 .
[0069] When the panels 1 and 2 are joined together, they can however occupy such a relative position in the direction D 2 that there is a small play A between the locking surface 10 and the locking groove 14 . This mechanical connection in the direction D 2 allows mutual displacement of the panels 1 , 2 in the direction of the joint, which considerably facilitates the laying and enables joining together the short sides by snap action.
[0070] As appears from FIGS. 4 a and 4 b , each panel in the system has a strip 6 at one long side 3 and a locking groove 14 at the other long side 4 , as well as a strip 6 ′ at one short side 3 ′ and a locking groove 14 ′ at the other short side 4 ′.
[0071] Furthermore, the joint edge 3 of the strip panel 1 has in its underside 18 a recess 20 extending throughout the entire joint edge 3 and forming together with the upper face 22 of the strip 6 a laterally open recess 24 . The joint edge 4 of the groove panel 2 has in its top side 26 a corresponding recess 28 forming a locking tongue 30 to be accommodated in the recess 24 so as to form a mechanical connection locking the joint edges 3 , 4 to each other in the direction designated D 1 . This connection can be achieved with other designs of the joint edges 3 , 4 , for example by a bevel thereof such that the joint edge 4 of the groove panel 2 passes obliquely in underneath the joint edge 3 of the strip panel 1 to be locked between that edge and the strip 6 .
[0072] The panels 1 , 2 can be taken up in the reverse order of laying without causing any damage to the joint, and be laid again.
[0073] The strip 6 is mounted in a tolerance-equalising groove 40 in the underside 18 of the strip panel 1 adjacent the joint edge 3 . In this embodiment, the width of the equalising groove 40 is approximately equal to half the width of the strip 6 , i.e. about 15 mm. By means of the equalising groove 40 , it is ensured that there will always exist between the top side 21 of the panel 1 and the bottom of the groove 40 an exact, predetermined distance E which is slightly smaller than the minimum thickness (2.8 mm) of the floor panels 1 , 2 . The groove panel 2 has a corresponding tolerance-equalising surface or groove 42 in the underside 16 of the joint edge 4 . The distance between the equalising surface 42 and the top side 26 of the groove panel 2 is equal to the aforementioned exact distance E. Further, the thickness of the strip 6 is so chosen that the underside 44 of the strip is situated slightly below the undersides 18 and 16 of the floor panels 1 and 2 , respectively. In this manner, the entire joint will rest on the strip 6 , and all vertical downwardly-directed forces will be efficiently transmitted to the subfloor 12 without any stresses being exerted on the joint edges 3 , 4 . Thanks to the provision of the equalising grooves 40 , 42 , an entirely even joint will be achieved on the top side, despite the thickness tolerances of the panels 1 , 2 , without having to perform any grinding or the like across the whole panels. Especially, this obviates the risk of damage to the bottom layer of the compact laminate, which might give rise to bulging of the panels.
[0074] Reference is now made to the embodiment of FIGS. 2 a - c showing in a succession substantially the same laying method as in FIGS. 1 a and 1 b . The embodiment of FIGS. 2 a - c primarily differs from the embodiment of FIGS. 1 a and 1 b in that the strip 6 is mounted on the strip panel 1 by means of a mechanical connection instead of glue. To provide this mechanical connection, illustrated in more detail in FIG. 6, a groove 50 is provided in the underside 18 of the strip panel 1 at a distance from the recess 24 . The groove 50 may be formed either as a continuous groove extending throughout the entire length of the panel 1 , or as a number of separate grooves. The groove 50 defines, together with the recess 24 , a dovetail gripping edge 52 , the underside of which exhibits an exact equalising distance E to the top side 21 of the strip panel 1 . The aluminium strip 6 has a number of punched and bent tongues 54 , as well as one or more lips 56 which are bent round opposite sides of the gripping edge 52 in clamping engagement therewith. This connection is shown in detail from below in the perspective view of FIG. 6.
[0075] Alternatively, a mechanical connection between the strip 6 and the strip panel 1 can be provided as illustrated in FIG. 7 showing in section a cut-away part of the strip panel 1 turned upside down. In FIG. 7, the mechanical connection comprises a dovetail recess 58 in the underside 18 of the strip panel 1 , as well as tongues/lips 60 punched and bent from the strip 6 and clamping against opposing inner sides of the recess 58 .
[0076] The embodiment of FIGS. 2 a - c is further characterised in that the locking element 8 of the strip 6 is designed as a component bent from the aluminium sheet and having an operative locking surface 10 extending at right angles up from the front side 22 of the strip 6 through a height of e.g. 0.5 mm, and a rounded guide surface 34 facilitating the insertion of the locking element 8 into the locking groove 14 when angling down the groove panel 2 towards the subfloor 12 (FIG. 2 b ), as well as a portion 36 which is inclined towards the subfloor 12 and which is not operative in the laying method illustrated in FIGS. 2 a - c.
[0077] Further, it can be seen from FIGS. 2 a - c that the joint edge 3 of the strip panel 1 has a lower bevel 70 which cooperates during laying with a corresponding upper bevel 72 of the joint edge 4 of the groove panel 2 , such that the panels 1 and 2 are forced to move vertically towards each other when their joint edges 3 , 4 are moved up to each other and the panels are pressed together horizontally.
[0078] Preferably, the locking surface 10 is so located relative to the joint edge 3 that when the groove panel 2 , starting from the joined position in FIG. 2 c , is pressed horizontally in the direction D 2 against the strip panel 1 and is turned angularly up from the strip 6 , the maximum- distance between the axis of rotation A of the groove panel 2 and the locking surface 10 of the locking groove is such that the locking element 8 can leave the locking groove 14 without coming into contact with it.
[0079] [0079]FIGS. 3 a - 3 b show another joining method for mechanically joining together the floor panels of FIGS. 2 a - c . The method illustrated in FIGS. 3 a - c relies on the fact that the strip 6 is resilient and is especially useful for joining together the short sides of floor panels which have already been joined along one long side as illustrated in FIGS. 2 a - c . The method of FIGS. 3 a - c is performed by first placing the two panels 1 and 2 flat on the subfloor 12 and then moving them horizontally towards each other according to FIG. 3 b . The inclined portion 36 of the locking element 8 then serves as a guide surface which guides the joint edge 4 of the groove panel 2 up on to the upper side 22 of the strip 6 . The strip 6 will then be urged downwards while the locking element 8 is sliding on the equalising surface 42 . When the joint edges 3 , 4 have been brought into complete engagement with each other horizontally, the locking element 8 will snap into the locking groove 14 (FIG. 3 c ), thereby providing the same locking as in FIG. 2 c . The same locking method can also be used by placing, in the initial position, the joint edge 4 of the groove panel with the equalising groove 42 on the locking element 10 (FIG. 3 a ). The inclined portion 36 of the locking element 10 then is not operative. This technique thus makes it possible to lock the floor panels mechanically in all directions, and by repeating the laying operations the whole floor can be laid without using any glue.
[0080] The invention is not restricted to the preferred embodiments described above and illustrated in the drawings, but several variants and modifications thereof are conceivable within the scope of the appended claims. The strip 6 can be divided into small sections covering the major part of the joint length. Further, the thickness of the strip 6 may vary throughout its width. All strips, locking grooves, locking elements and recesses are so dimensioned as to enable laying the floor panels with flat top sides in a manner to rest on the strip 6 in the joint. If the floor panels consist of compact laminate and if silicone or any other sealing compound, a rubber strip or any other sealing device is applied prior to laying between the flat projecting part of the strip 6 and the groove panel 2 and/or in the recess 26 , a moisture-proof floor is obtained.
[0081] As appears from FIG. 6, an underlay 46 , e.g. of floor board, foam or felt, can be mounted on the underside of the panels during the manufacture thereof. In one embodiment, the underlay 46 covers the strip 6 up to the locking element 8 , such that the joint between the underlays 46 becomes offset in relation to the joint between the joint edges 3 and 4 .
[0082] In the embodiment of FIG. 5, the strip 6 and its locking element 8 are integrally formed with the strip panel 1 , the projecting part of the strip 6 thus forming an extension of the lower part of the joint edge 3 . The locking function is the same as in the embodiments described above. On the underside 18 of the strip panel 1 , there is provided a separate strip, band or the like 74 extending throughout the entire length of the joint and having, in this embodiment, a width covering approximately the same surface as the separate strip 6 of the previous embodiments. The strip 74 can be provided directly on the rear side 18 or in a recess formed therein (not shown), so that the distance from the front side 21 , 26 of the floor to the rear side 76 , including the thickness of the strip 74 , always is at least equal to the corresponding distance in the panel having the greatest thickness tolerance. The panels 1 , 2 will then rest, in the joint, on the strip 74 or only on the undersides 18 , 16 of the panels, if these sides are made plane.
[0083] When using a material which does not permit downward bending of the strip 6 or the locking element 8 , laying can be performed in the way shown in FIG. 5. A floor panel 2 a is moved angled upwardly with its long side 4 a into engagement with the long side 3 of a previously laid floor panel 1 while at the same time a third floor panel 2 b is moved with its short side 4 b ′ into engagement with the short side 3 a ′ of the upwardly-angled floor panel 2 a and is fastened by angling the panel 2 b downwards. The panel 2 b is then pushed along the short side 3 a ′ of the upwardly-angled floor panel 2 a until its long side 4 b encounters the long side 3 of the initially-laid panel 1 . The two upwardly-angled panels 2 a and 2 b are therefore angled down on to the subfloor 12 so as to bring about locking.
[0084] By a reverse procedure the panels can be taken up in the reverse order of laying without causing any damage to the joint, and be laid again.
[0085] Several variants of preferred laying methods are conceivable. For example, the strip panel can be inserted under the groove panel, thus enabling the laying of panels in all four directions with respect to the initial position. | The invention relates to a system for laying and mechanically joining building panels, especially thin, hard, floating floors. Adjacent joint edges ( 3, 4 ) of two panels ( 1, 2 ) engage each other to provide a first mechanical connection locking the joint edges ( 3,4 ) in a first direction (D 1 ) perpendicular to the principal plane of the panels. In each joint, there is further provided a strip ( 6 ) which is integrated with one joint edge ( 3 ) and which projects behind the other joint edge ( 4 ). The strip ( 6 ) has an upwardly protruding locking element ( 8 ) engaging in a locking groove ( 14 ) in the rear side ( 16 ) of the other joint edge ( 4 ) to form a second mechanical connection locking the panels ( 1, 2 ) in a second direction (D 2 ) parallel to the principal plane of the panels and at right angles to the joint. Both the first and the second mechanical connection allow mutual displacement of joined panels ( 1, 2 ) in the direction of the joint. | 4 |
FIELD OF THE INVENTION
[0001] The invention relates to enzymatic pretreatment of wood chips to improve the chips for downstream processing, such as lowered energy consumption during refining of the chips.
BACKGROUND
[0002] Wood pulps are generally produced through multistep processes. Initially, logs can be subjected to grinding in which the logs are forced against a rotating abrasive stone which separates the fibers from the log and also the wood cell matrix. In a refining process, wood chips are fed between two metal discs, with at least one disc rotating. In both cases, essentially all of the constituents of wood are retained in the pulp that is eventually produced. Such pulp contains fiber bundles, fiber fragments and whole fibers. A lack of uniformity of pulp and constituents and the presence of lignin in the pulp give it certain desirable qualities, such as yield, paper bulk and opacity as well as good printability. The pulp also has less desirable properties for some paper types, such as low strength, relatively coarse surface and a lack of durability.
[0003] Chips to be refined can be destructured and impregnated with chemicals or enzymes prior to further mechanical treatment. This can help increase pulp quality or reduce energy consumption. These methods create slightly different pulps and also vary with the species of wood species, quality of the wood, processing conditions and the amount of energy applied. Various forms exist: thermomechanical pulping (TMP), refiner pulping, stone groundwood pulping, etc.
[0004] Chip “destructuring” is usually carried out in the first stage refiner where it occurs in combination with some fiber fibrillation. The difficulty of clearly separating these two steps can lead to an unnecessary increase in energy while no significant gain in pulp properties is obtained. Several pieces of equipment have been developed to overcome these drawbacks. U.S. Pat. No. 5,813,617 of Toma, for example, describes one such device. Other devices incorporate compressive forces along with the destructuring shear forces. These compressive forces along with the accompanied decompression can be used to enhance the penetration of chemicals or enzymes for impregnation prior to refining.
[0005] In TMP, steam is added to the chips being refined to facilitate pulping and lower electricity consumption. Steam is also produced during refining and heat recovery systems can help recoup some of the energy cost of the process. The electric motors used to operate these refiners require very large amounts of power. The TMP process generally involves several refining stages to produce a desirable pulp. However, only a small portion of the energy used in each refining stage is actually used to separate and develop the fibers. Screening is used after or between refining stages to separate adequately refined fibers from longer, coarser fibers. These tougher fibers are sent to “rejects” refiners for further development. Depending on the quality of refining, the amount of rejects needing additional refining can and usually is significant.
[0006] Woody biomass used in these mechanical pulping processes contains cellulose, hemicelluloses, lignin and extractives in varying amounts throughout the ultrastructure of its fibers. These various components act in conjunction to give these substrates mechanical strength and resistance to degradation. By selectively removing or altering certain components, it is possible to reduce the amount of energy required to separate and refine these fibers. The patent literature describes various approaches using different enzyme mixtures. For example US Patent Publication No. 2005/0000666, of Taylor et al., describes the use of mannanase and xylanase. Certain treatments have been found to significantly impact paper strength properties which have limited their applications. U.S. Pat. No. 5,865,949, of Pere et al., describes a process using an enzyme mixture containing endo-β-glucanase (EG), a limited mannanase and cellobiohydrolase (CBH) activity which reduces the negative effects on paper strength. U.S. Pat. No. 6,099,688, of Pere et al., describes the use of isolated cellobiohydrolase to increase the amount of relative amorphousness of the cellulose within the fibers. This process is said to cause even less damage to paper properties.
[0007] International patent publication No. WO 97/40194, of Eachus et al., suggests changing the structure or the composition of the wood by adding to compressed chips fungal or bacterial cultures or products, such as enzymes obtained from them, by means of pressure. The purpose of the compression is to make cracks and fractures in the wood. When the chips are released from the compression, microbes of their products, while the chips expand, are absorbed by the structures of the wood partially by the virtue of negative pressure, partially by the capillary action. The use of lipolytic, proteolytic, linginolytic, cellulolytic and hemicellulolytic enzymes is mentioned. The patent specification describes the absorption of the enzyme preparation Clariant Cartazyme HS™ into the compressed chips after releasing the pressure. Liquid was removed after the treatment, and mechanical pulp was prepared from the chips. In that case, the amount of energy consumed was 7.5% less than in the case of chips that were treated with a buffer only. In another test, the enzyme preparations Clariant Cartazyme NS™ and Sigma porcine pancreas Lipase L-3126 were used. In that case, the amount of energy consumed was 12.5% less than when treated with a buffer only.
[0008] A more recent pre-treatment of chips using an enzyme preparation containing cellobiohydrolase and endoglucanase was suggested by Pere in United States Patent Publication No. 2007/0151683. Here again, it was said to be preferable to carry out the enzymatic treatment by compressing the chips and by bringing the compressed chips in a liquid phase into contact with the enzyme composition to absorb the enzyme composition into the chips. The process is said to be useful for reducing the specific energy consumption (SEC) of mechanical pulp and to improve the technical properties of the fibers.
SUMMARY
[0009] The invention provides a method for preparing mechanical pulp. The method includes: (i) exposing compressed wood chips to an enzymatic solution comprising an endoglucanase (EG) and a cellobiohydrolase (CBH), wherein the ratio of enzymatic activity of EG:CBH is at least 3, and permitting the wood chips to decompress. The product of step (i) can be refined for further processing in the production e.g. of pulp for the manufacture of paper products.
[0010] The enzymatic activity of the CBH in the enzymatic solution is typically at least 0.5 FPU per gm of wood chips. The dry weight of the wood substrate can be measured according to standard T 258 om-06. It is possible use CBH in an amount that provides greater activity e.g., in a range from 0.5 to 200 FPU, or 1 to 150 FPU, or 5 to 150, or 10 to 150, or 20 to 150, or 30 to 150, or 40 to 150, or 50 to 150, or 70 to 150, or 100 to 150 FPU, or 50 to 130 FPU, or 50 to 110 FPU per gram of wood chips etc., or the activity can be about any of the foregoing values. A preferred range is between 0.1 and 5 FPU per gm of wood chips.
[0011] In embodiments, the enzymatic solution also contains a hemicellulase, typically the enzymatic activity of the hemicellulase being at least 1.5 times the activity of the CBH. A preferred hemicellulase is a mannanase (MAN).
[0012] As described in the examples, wood chips can be exposed to the enzymatic solution for sufficient time to reduce energy consumption during subsequent refining of the wood chips to pulp in which the freeness of the pulp (CSF) obtained is reduced by at least 5% in comparison to the freeness of pulp obtained by refining chips which have not been exposed to the enzymatic solution. The energy reduction can be at least 5%, but can be greater e.g., at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 11% or at least 12%, or can be about any of these amounts.
[0013] Suitable enzymatic activity is provided by EG, CBH, and MAN classified as EC 3.2.1.6, EC 3.2.1.91, and EC 3.2.1.78, respectively.
[0014] Enzymatic activity of the EG can be at least 1850 CMCU per gm of wood chips and/or MAN is at least 250 IU per gm of wood chips.
[0015] The enzymatic solution can contain enzymatic protein having of between 0.02 mg/g to 20 mg/g of the wood chips.
[0016] Wood chips can be softwood, for example, Black Spruce, Picea mariana , used in the examples described below. The chips can be made up of from 38 to 52% by weight cellulose, from 20 to 30% by weight lignin, from 20 to 30% by weight hemicellulose. The hemicellulose component can be from 15 to 20% mannans by total weight of the wood chips and from 15 to 20% xylans by total weight of the wood chips.
[0017] In preferred embodiments, the wood chips are destructured wood chips having an average weight per chip in the range of from 0.8 to 2 g.
[0018] The method can include the step of compressing wood chips to form the compressed wood chips that are to be permitted to be decompressed while exposed to the enzymatic solution.
[0019] The wood chips can be subjected to steaming prior to being compressed.
[0020] Wood chips having an average size of, prior to compression, between 15 to 35 mm long by 15 to 35 mm wide and between 2 to 8 mm thick are suitable.
[0021] Compressing the wood chips can include subjecting the chips to a pressure in the range of from 50 to 600 atm. A preferred minimum pressure is 100 atm.
[0022] In an embodiment, wood chips are compressed by at least 10% of their uncompressed volume.
[0023] Compression of the wood chips can be accomplished through the use of e.g., screw clamp, or press or, a hydraulic press. Compression can include the chips to pressure for a period of between 10 minutes and 5 hours. In many cases, 10 to 30 minutes is acceptable.
[0024] Compression of the wood chips can be conducted prior to exposing of the compressed wood chips to the enzymatic solution or in the presence of the enzymatic solution.
[0025] Decompression can take place at atmospheric pressure in an aqueous solution for a period of time in which a final consistency in the range of from 0.3 to 30% is reached, preferably a range of from 5 to 15%.
[0026] Refining the wood chips that have been enzymatically treated can be conducted to obtain a mechanical wood pulp having a drainability of at least 100 ml CSF.
[0027] The method can also include chipping raw wood material to form wood chips which can then be compressed and destructured for enzymatic treatment.
[0028] An embodiment of the invention is also a method for treating wood chips for eventual use in preparing mechanical pulp e.g., refining. In this sense, the embodiment can be regarded as a method for preparing feedstock for a mechanical pulping process. The method includes exposing compressed wood chips to an enzymatic solution comprising an endoglucanase (EG) and a cellobiohydrolase (CBH), wherein the ratio of enzymatic activity of EG:CBH is at least 3. Other features associated with the enzymatic treatment, described above, and below in connection with the examples, can of course be included in this treatment. Downstream processing can include subjecting treated wood chips to mechanical pulping, which can be a thermomechanical refining process or a chemithermomechanical refining process. A paper product can be manufactured downstream, be it in a separate mill or as part of an in-line process.
[0029] So, an aspect of the present invention is a method for reducing the amount of energy required to refine destructured chips by treating said chips with an enzymatic solution containing a plurality of enzymes and optionally stabilizer compound(s) during decompression. This solution can be a combination of CBH, EG, mannanase and stabilizer agents and surfactants containing mainly propylene glycol, glycerol, sorbitol and to a lesser degree proxel, potassium sorbate and ethoxylated fatty alcohols. The enzymatic treatment can be carried out at process temperatures of from 20° C. to 80° C., for example between 40° C. and 60° C. The enzymatic treatment can be carried out at a pH of from about 2 to about 10. The treatment time can be from 30 minutes to 10 hours. Other temperatures, pHs and or times can be used.
[0030] The reduction in energy can be manifest as reduced energy consumption during primary, secondary, tertiary, reject, post-refining or other mechanical treatment used to obtain a desired final pulp from a destructured wood chip that has been treated with the enzyme solution prior to refining.
[0031] The enzyme solution used herein preferably possesses the following relative activities: the EG should have a 10 fold greater activity than the CBH and the mannanase should have a 2 fold greater activity than the CBH. This enzyme solution is available commercially from Novozymes® under the name Celluclast 1.5L™.
[0032] Methods of refining chips with lower energy requirements to obtain a desirable degree of refining are set forth herein. Methods for refining the chips wherein the refining process includes mechanical destructuring including compression and decompression, of wood chips followed by treatment of the obtained destructured chips with a complex enzyme mixture are presented, wherein the resultant pulp and/or paper products have maintained tensile strength, improved optical properties and slightly reduced tear index as compared to untreated pulps or products therewith.
[0033] Pulp and paper products made therefrom having maintained tensile strength, improved optical properties and slightly reduced tear strength are provided. Pulp and papers made therefrom which require less energy to produce are provided.
[0034] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are only intended to provide a further explanation of the present invention as claimed
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Embodiments illustrating the invention and establishing feasibility of various aspects thereof are described below with reference to the accompanying drawings, in which:
[0036] FIG. 1 is a bar graph showing the amount of sugars released per gram of oven dried chips (OD) into the liquor after a 1 hour enzyme hydrolysis (5 FPU/g OD Celluclast 1.5L™) at different compression conditions;
[0037] FIG. 2 is a bar graph showing freeness (CSF) after a 1 hour enzyme hydrolysis (5 FPU/g OD Celluclast 1.5L™) at different compression conditions; and
[0038] FIG. 3 is a bar graph showing specific energy consumption (SEC) during laboratory scale refining of wood chips that had been compressed at different conditions and subjected to enzyme hydrolysis (10 FPU/g OD Celluclast 1.5L™) for one hour during decompression i.e., at atmospheric pressure.
DETAILED DESCRIPTION
[0039] The present invention relates to a method of refining chips into pulps, wherein the method includes the use of an enzyme mixture containing cellulases and hemicellulase. Treatment with this solution following chip destructuring, compression and decompression prior to the entire refining process from primary, secondary, reject to post refining can reduce the energy required to reach a given degree of refining. This enzyme mixture is to contain a significant EG activity, a marked mannanase activity and a CBH activity that is lower than the first two but not negligible.
[0040] As used herein, an endo-β-glucanase is preferably a cellulase classified as EC 3.2.1.6—endo-1,3(4)-β-glucanase. This enzyme is preferably capable of endohydrolysis of 1,3- or 1,4-linkages in β-D-glucans when the glucose residue whose reducing group is involved in the linkage to be hydrolysed is itself substituted at C-3. This hydrolysis cleaves the O-glycosyl bond of the cellulose backbone.
[0041] As used herein, a “mannanase” is preferably a hemicellulase classified as EC 3.2.1.78, and called endo-1,4-β-mannosidase. Mannanase includes β-mannanase, endo-1,4-mannanase, and galactomannanase. Mannanase is preferably capable of catalyzing the hydrolysis of 1,4-β-D-mannosidic linkages in mannans, including glucomannans, galactomannans and galactoglucomannans. Mannans are polysaccharides primarily or entirely composed of D-mannose units.
[0042] As used herein, a cellobiohydrolase is preferably a cellulase classified as EC 3.2.1.91 and called cellulose 1,4-β-cellobiosidase (non-reducing end). This enzyme produces the hydrolysis of (1→4)-β-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains
[0043] EG activity can be determined following the carboxymethyl cellulose (CMC) method described in Measurement of Cellulase Activities by T. K. Ghose (Pure & Appl. Chem. Vol 69, No. 2, pp. 257-268, 1987). The amount of reducing sugars released from enzymatic hydrolysis of a 2% solution of a well characterized CMC is used to determine the enzymes EG activity. Sugar concentration is determined by the well known DNS method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959).
[0044] CBH activity can be determined following the filter paper assay method described in Measurement of Cellulase Activities by T. K. Ghose (Pure & Appl. Chem. Vol 69, No. 2, pp. 257-268, 1987). The amount of reducing sugars released from enzymatic hydrolysis of Whatman No. 1 filter paper strip of known size is used to determine the enzymes CBH activity. Sugar concentration is determined by the well known DNS method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959).
[0045] Mannanase activity can be determined following the method describer by M. Ratto and K. Poutanen (Biotechnology Letters, No 9, pp-661-664, 1988). The amount of reducing sugars released from enzymatic hydrolysis of a 0.5% solution of locust bean gum is used to determine the enzymes mannanase activity. Sugar concentration is determined by the well known DNS method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959).
[0046] An enzyme solution containing EG, CBH and mannanase activities in the correct ratios is commercially available from Novozymes® under the name Celluclast 1.5L™. This solution contains between 40 mg and 50 mg of total protein per millilitre of solution. When kept at between 0° C. and 25° C., the solution is stable and its activity is maintained for about 18 months. Storage at higher temperatures will reduce this effective storage time.
[0047] The enzyme solution can vary slightly in ratio of activities which still give the desired energy reductions and paper qualities. The amount of total protein in the correct ratio should be between 0.02 kg and 5 kg per metric ton of oven dried wood. This amount of total protein can vary depending on the type of woody substrate being used, for example virgin hardwood kraft, virgin softwood kraft, recycled pulp, groundwood, refiner groundwood, pressurized refiner groundwood, thermomechanical, chemithermomechanical or a mixture thereof; or the species of wood which makes up this substrate, for example Populus sp., Acer sp., Picea sp., Abies sp., Pinus sp., Conium sp., etc.
[0048] The destructured chips of the present invention can be treated with one or more other components, including polymers such as anionic and non-ionic polymers, clays, other fillers, dyes, pigments, defoamers, microbiocides, pH adjusting agents such as alum or hydrochloric acid, other enzymes, and other conventional papermaking or processing additives. These additives can be added before, during or after introduction of the enzyme solution. The enzyme solution can be added, and is preferably added to the papermaking pulp before the addition of coagulants, flocculants, fillers and other conventional and non-conventional papermaking additives, including additional enzymes.
[0049] The destructured chips can be any conventional softwood or hardwood species used in mechanical pulp production, such as spruce, fir, hemlock, aspen, acacia, birch, beech, eucalyptus, oak and other softwood and hardwood species. The destructured chips can contain cellulose fibers at a concentration of at 35% by weight based on the oven dried solids content of the wood. The final pulp can be, for example, virgin pulp (e.g. spruce, fir, pine, eucalyptus, and include virgin hardwood or virgin softwood), hardwood kraft, softwood kraft, recycled pulp, groundwood, refiner groundwood, pressurized refiner groundwood, thermomechanical, chemithermomechanical or mixtures thereof.
[0050] According to various embodiments, the papermaking system can include chip handling equipment with a chip destructuring device which is capable of destructuring and compressing wood chips, a primary refiner, a secondary refiner, a screen, a mixer, a latency and/or blend chest, and papermaking equipment, for example, screens. The papermaking system can also include metering devices for providing a suitable concentration of the enzyme composition or other additives to the flow of pulp. Valving, pumps, and metering equipment as known to those skilled in the art can also be used for introducing various additives described herein to the pulp.
[0051] According to one embodiment, the enzyme solution can be added to the chips before or during destructuring, compression or preferably immediately after compression ends and decompression begins, added to pulp after the pulp leaves the first refiner (also known as the primary refiner) during the refining process. For example, the enzyme solution can be added before the second refiner (also known as the secondary refiner), after the second refiner, before the screen, after the screen, before the mixer, after the mixer, before the latency and/or blend chest, to the latency and/or blend chest. For example, the enzyme solution can be added after the second refiner, between the screen and the mixer, or after the mixer. Other additives as described can be added to the papermaking system as known to those skilled in the art.
[0052] The destructured chips can be treated with the enzyme solution when the chips are at a temperature of from 10° C. to about 75° C., from about 30° C. to about 70° C., or from about 40° C. to about 65° C. The chips can be at a pH of from 2 to 10, from about 4 to 7, or from 4.5 to 5.5. A treatment time can be from 10 minutes to about 10 hours, from about 30 minutes to about 5 hours or from 1 hours to 2 hours.
[0053] The enzyme treatment is carried out before, during or immediately after the destructuring process, but before completion of the refining process. The enzyme treatment is carried out on “destructured wood chips”. “Destructured wood chips” refers to a woody material used as the raw material of the mechanical pulp, which has been subjected to at least one mechanical destructuring process step. The term destructured wood chips therefore encompasses, e.g. chips of various sizes, compressed and uncompressed destructured wood chips, matchsticks and fiber bundles. Preferably, the enzyme treatment is carried out on destructured wood chips. More preferably the enzyme solution is carried out on destructured wood chips during decompression of the chips.
[0054] In another embodiment, the enzyme solution can be added during the chip handling prior to destructuring. As an example, the enzyme solution can be added after chip washing at the chip bin. In this embodiment, the chips are treated and directed to a destructuring device before compression-decompression prior to a primary refiner. The pulp is then refined to desired specifications before being returned to the papermaking system stream.
[0055] The introduction of the enzyme solution can be made at one or more points and the introduction can be continuous, semi-continuous, batch, or combinations thereof.
[0056] According to various embodiments, the chip to liquor ratio can be about 1 to 20, 1 to 10, or 1 to 5.
[0057] Various ranges of components such as enzymatic activities, times, pressures, and values of such are described herein. It is to be understood that additional combinations of such ranges and values are also disclosed by such descriptions. As a general example, a range of from 2 to 5 describes values of about 2 and about 5; values of about 2, 3, 4 and 5 describes ranges of 2 to 5, 3 to 4, 2 to 4, etc.
[0058] Chips processed as described herein can exhibit maintained tensile strength, while suffering some loss of tear strength. Paper products made from the pulp also maintain tensile strength while losing some tear strength. The addition of the enzyme solution creates fiber weaknesses which allow the formation of shorter fibers but also enhance fiber fibrillation which is why tear is affected while tensile strength is maintained. Fines production increases, thus lowering freeness at a given specific energy of refining SEC. The addition of the enzyme solution to chips reduces the amount of SEC needed to obtain a desired level of freeness.
[0059] A pulp produced by the methods described herein can be used in the production of paper products, including, for example, cardboard, paper towels, newspaper, and hygiene products. The methods described herein can also be suitable for textile manufacturing.
EXAMPLES
Example 1
Enzymatic Activities
[0060] The commercial enzyme product, Celluclast 1.5L™, was tested for several enzymatic activities and was found to have several different types of activities. The following table list all relevant and significantly measurable activities and protein concentration.
[0061] Carboxymethyl cellulase (CMC) activity, equivalent to endo-β-glucanase activity, was determined following the CMC method described in Measurement of Cellulase Activities by T. K. Ghose (Pure & Appl. Chem. Vol 69, No. 2, pp. 257-268, 1987). The amount of reducing sugars released from enzymatic hydrolysis of a 2% solution of a well characterized CMC during a 30.0 minute hydrolysis at pH 4.8 and 50° C. is used to determine the enzymes EG activity. Sugar concentration is determined by the well known 3,5-dinitrosalicylic acid (DNS) solution method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959). The addition of the DNS solution to the hydrolysis filtrate stops the reaction. The mixture was boiled for 5.0 minutes to allow for color formation. After cooling, the absorbency is measured at 540 nm and the concentration is determined against a standard curve.
[0062] Mannanase activity was determined following the method describer by M. Ratto and K. Poutanen (Biotechnology Letters, No 9, pp-661-664, 1988). The amount of reducing sugars released from enzymatic hydrolysis of a 0.5% solution of locust bean gum during a 30.0 minute hydrolysis at pH 4.8 and 50° C. is used to determine mannanase activity. Sugar concentration is determined by the well known DNS method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959) and described thoroughly above.
[0063] Filter paper activity, equivalent to CBH activity, was determined following the filter paper assay method described in Measurement of Cellulase Activities by T. K. Ghose (Pure & Appl. Chem. Vol 69, No. 2, pp. 257-268, 1987). This method uses the amount of reducing sugars released from enzymatic hydrolysis of Whatman No. 1 filter paper strip of known size during a 30.0 minute hydrolysis at pH 4.8 and 50° C. to determine the enzymes CBH activity. Sugar concentration is determined by the well known DNS method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959) and described thoroughly above.
[0064] Protein concentration was determined using the Bradford assay. Bradford assay kits purchased from Sigma-Aldrich were used. This well known method uses the binding of protein with a solution of Coomassie Blue which allows colorimetric determination of protein concentration based on a standard curve produced using bovine serum albumin. Absorbency is measured at 595 nm.
[0000]
Measured parameters of Celluclast 1.5L ™
Parameter
Value
Unit
Endo-β-glucanase
1860
CMC/ml
Mannanase activity
285
IU/ml
Cellobiohydrolase
150
FPU/ml
Total protein
43.4
mg/ml
Example 2
Sugars Released
[0065] The enzyme solution was added to destructured chips (200 g ODP) using the solutions filter paper activity as a dosage indicator. Different compression conditions at 5 FPU/g OD (10 and 20 minutes held under compression) and controls were done in duplicate and measured in duplicate for a total of four data sets. Hydrolysis was carried out at a consistency of 10%, a temperature of 50° C. and a time of 1 hour. After which, the samples were filtered and the filtrate was treated using the well known 3,5-dinitrosalicylic acid (DNS) solution method described by G. L. Miller (Analytical Chem., No. 31, p. 426, 1959). The addition of the DNS solution to the hydrolysis filtrate stops the reaction. The mixture was boiled for 5.0 minutes to allow for color formation. After cooling, the absorbency is measured at 540 nm and the concentration is determined against a standard curve. This is also shown in FIG. 1 .
[0000]
Sugars released during lab-scale compression testing 5 FPU/g
OD Celluclast 1.5L ™
Standard
Sugars released into
deviation
Treatment
liquor (mg/g ODP)
(mg/g ODP)
Destructured chips 0 compression
0.08
0
0 FPU/g OD (−control)
Destructured chips 0 compression
2.27
0.31
5 FPU/g OD (+control)
Destructured chips 10 minutes
2.80
0.24
compression 5 FPU/g OD
Destructured chips 20 minutes
3.03
0.41
compression 5 FPU/g OD
Example 3
Freeness
[0066] The enzyme solution was added to destructured chips (200 g ODP) using the solutions filter paper activity as a dosage indicator. Different compression conditions at 5 FPU/g OD (10 and 20 minutes held under full compression) and a control were done in duplicate. Hydrolysis was carried out at a consistency of 10%, a temperature of 50° C. and a time of 1 hour. After this treatment, chips were dewatered to 20% consistency and refined in three stages using a KRK refiner with disc gaps of 0.5, 0.3 and 0.15 mm. Refined pulp was collected and moisture was checked prior to measuring Canadian Standard Freeness (CSF). Results are shown in the following table and FIG. 2 .
[0000]
Freeness of pulp treated with Celluclast 1.5L ™ trials
before refining
Treatment
CSF (ml)
Standard deviation (ml)
Destructured chips 0 compression
182
3
0 FPU/g OD (−control)
Destructured chips 0 compression
176
4
5 FPU/g OD (+control)
Destructured chips 10 minutes
160
2
compression 5 FPU/g OD
Destructured chips 20 minutes
169
3
compression 5 FPU/g OD
Example 4
Energy Savings
[0067] The enzyme solution was added to destructured chips (200 g ODP) using the solutions filter paper activity as a dosage indicator. Different compression conditions at 10 FPU/g OD (10 and 20 minutes held under full compression) and a control were done in duplicate. Hydrolysis was carried out at a consistency of 10%, a temperature of 50° C. and a time of 1 hour. After this treatment, chips were dewatered to 20% consistency and refined in three stages using a KRK refiner with disc gaps of 0.5, 0.3 and 0.15 mm and a control were done in duplicate. Energy consumption was monitored with an online monitor and networked computer. Results are shown in the following table and in FIG. 3 .
[0000]
Specific energy consumption (SEC) obtained during refining of
destructured wood chips treated with Celluclast ™ 1.5L
Net SEC
Standard
Energy
average
deviation
savings
Treatment
(kWh/t)
(kWh/t)
(%)
Destructured chips 0
3018.5
0
0
compression 0 FPU/g OD
(−control)
Destructured chips 0
3046
53.0
+0.91
compression 10 FPU/g OD
(+control)
Destructured chips 10 minutes
2671
102.5
−11.5
compression 10 FPU/g OD
Destructured chips 20 minutes
2873.5
99.0
−4.8
compression 10 FPU/g OD
* No-load energy consumption (3 minutes of warm up energy was calculated to be 0.12456 kWh) was subtracted from the meter reading to give the net energy consumption
[0068] All patents, applications and publications mentioned above and throughout this disclosure are incorporated in their entirety by reference herein. | A process using a multicomponent enzyme preparation to treat chips that have been crushed using a device that combines shear and compressive forces where treatment occurs mainly during decompression and reduces the specific energy consumption and/or increasing production of subsequent refining while maintaining or increasing handsheet physical properties. The enzyme preparation is to have a major endoglucanase activity, a significant mannanase activity and a slight cellobiohydrolase activity. This enzyme mixture is prepared from a genetically modified strain of Trichoderma reseii. | 3 |
FIELD OF THE INVENTION
[0001] This invention relates to compounds and compositions comprising specific salts of saturated [2.2.2] dicarboxylate in order to provide highly desirable properties within thermoplastic (e.g., polyolefin) articles. The inventive salts and derivatives thereof are useful as nucleating and/or clarifying agents for such thermoplastics, are easy to produce and handle, and relatively inexpensive to manufacture. Such compounds induce high peak crystallization and improved stiffness within thermoplastics. Also, thermoplastic compositions comprising such novel nucleating agents exhibit improved heat distortion properties and clarity levels in comparison with the closest unsaturated salt nucleating agents. Thermoplastic additive compositions and methods of producing thermoplastics with such compounds are also contemplated within this invention.
BACKGROUND OF THE PRIOR ART
[0002] All U.S. patents cited below are herein entirely incorporated by reference.
[0003] As used herein, the term “thermoplastic” is intended to mean a polymeric material that will melt upon exposure to sufficient heat but will retain its solidified state, but not prior shape without use of a mold or like article, upon sufficient cooling. Specifically, as well, such a term is intended solely to encompass polymers meeting such a broad definition that also exhibit either crystalline or semi-crystalline morphology upon cooling after melt-formation. Particular types of polymers contemplated within such a definition include, without limitation, polyolefin (such as polyethylene, polypropylene, polybutylene, and any combination thereof), polyamides (such as nylon), polyurethanes, polyesters (such as polyethylene terephthalate), and the like (as well as any combinations thereof).
[0004] Thermoplastics have been utilized in a variety of end-use applications, including storage Containers, medical devices, food packages, plastic tubes and pipes, shelving units, and the like. Such base compositions, however, must exhibit certain physical characteristics in order to permit widespread use. Specifically within polyolefin, for example, uniformity in arrangement of crystals upon crystallization is a necessity to provide an effective, durable, and versatile polyolefin article. In order to achieve such desirable physical properties, it has been known that certain compounds and compositions provide nucleation sites for polyolefin crystal growth during molding or fabrication. Generally, compositions containing such nucleating compounds crystallize at a much faster rate than un-nucleated polyolefin. Such crystallization at higher temperatures results in reduced fabrication cycle times and a variety of improvements in physical properties, such as, as one example, stiffness.
[0005] Such compounds and compositions that provide faster and or higher polymer crystallization temperatures are thus popularly known as nucleators. Such compounds are, as their name suggests, utilized to provide nucleation sites for crystal growth during cooling of a thermoplastic molten formulation. Generally, the presence of such nucleation sites results in a larger number of smaller crystals. As a result of the smaller crystals formed therein, clarification of the target thermoplastic may also be achieved, although excellent clarity is not always a result. The more uniform, and preferably smaller, the crystal size, the less light is scattered. In such a manner, the clarity of the thermoplastic article itself can be improved. Thus, thermoplastic nucleator compounds are very important to the thermoplastic industry in order to provide enhanced clarity, physical properties and/or faster processing.
[0006] As an example of one type of nucleator, dibenzylidene sorbitol derivative compounds are typical nucleator compounds, particularly for polypropylene end products. Compounds such as 1,3-O-2,4-bis(3,4-dimethylbenzylidene) sorbitol, available from Milliken Chemical under the trade name Millad® 3988, provide excellent nucleation characteristics for target polypropylenes and other polyolefin. Other well known compounds include sodium benzoate, sodium 2,2′-methylene-bis-(4,6-di-tert-butylphenyl) phosphate (from Asahi Denk Kogyo K.K., known as NA-11), aluminum bis[2,2′-methylene-bis-(4,6-di-tert-butylphenyl)phosphate] (also from Asahi Denka Kogyo K.K., known as NA-21), talc, and the like. Such compounds all impart high polyolefin crystallization temperatures; however, each also exhibits its own drawback for large-scale industrial applications.
[0007] Other acetals of sorbitol and xylitol are typical nucleators for polyolefin and other thermoplastics as well. Dibenzylidene sorbitol (DBS) was first disclosed in U.S. Pat. No. 4,016,118 by Hamada, et al. as effective nucleating and clarifying agents for polyolefin. Since then, large numbers of acetals of sorbitol and xylitol have been disclosed. Representative references of such other compounds include Mahaffey, Jr., U.S. Pat. No. 4,371,645[di-acetals of sorbitol having at least one chlorine or bromine substituent].
[0008] As noted above, another example of the effective nucleating agents are the metal salts of organic acids. Wijga in U.S. Pat. Nos. 3,207,735, 3,207,736, and 3,207,738, and Wales in U.S. Pat. Nos. 3,207,737 and 3,207,739, suggest that aliphatic, cycloaliphatic, and aromatic carboxylic, dicarboxylic or higher polycarboxylic acids, and corresponding anhydrides and metal salts, are effective nucleating agents for polyolefin. They further state that benzoic acid type compounds, in particular sodium benzoate, are the best nucleating agents for their target polyolefin.
[0009] Another class of nucleating agents was suggested by Nakahara, et al. in U.S. Pat. No. 4,463,113, in which cyclic bis-phenol phosphates was disclosed as nucleating and clarifying agents for polyolefin resins. Kimura, et al. then suggests in U.S. Pat. No. 5,342,868 that the addition of an alkali metal carboxylate to basic polyvalent metal salt of cyclic organophosphoric ester can further improve the clarification effects of such additives. Compounds that are based upon this technologies are marketed under the trade name NA-11 and NA-21.
[0010] Furthermore, a certain class of bicyclic compounds, such as bicyclic dicarboxylic acid and salts, have been taught as polyolefin nucleating agents as well within Patent Cooperation Treaty Application WO 98/29494, 98/29495 and 98/29496, all assigned to Minnesota Mining and Manufacturing. The best working examples of this technology is embodied in disodium bicyclo[2.2.1]heptene dicarboxylate, disodium bicyclo[2.2.2]octene dicarboxylated and camphanic acid. Formulations with such compounds are also contemplated within the inventions.
[0011] The efficacy of the nucleating agents are typically measured by the peak crystallization temperature of the polymer compositions containing such nucleating agents. A high polymer peak crystallization is indicative of high nucleation efficacy, which generally translates into fast processing cycle time and more desirable physical properties, such as stiffness/impact balance etc., for the fabricated parts.
[0012] It is also very desirable that the nucleating agents induce improved clarity in the fabricated parts. DBS based Nucleating agents are known to provide excellent clarity in polypropylene articles. For example, 3,4-dimethyl DBS, marketed under the trade name Millad 3988 is an exceptional clarifier. However, DBS based nucleating agents generally suffer from higher level of migration and certain ones [for example bis(p-methyl benzylidene) sorbitol)] from highly undesirable taste and odor transfer. Site nucleators, which are loosely defined as nucleating agents that are not soluble in molten polyolefin, provide better performance in migration, taste and odor transfer. Typically site nucleators include Na-11, sodium benzoate and alike. Site nucleators generally do not afford sufficient clarification effect in polyolefin articles. Therefore, there is a long felt need for a site nucleating agents with improved clarification property.
[0013] Depending upon the application, polyolefin articles can be subjected to elevated temperature and mechanical stress for a long period of time. Such applications might include food and beverage containers, automotive parts, certain outdoor application. Dimensional stability at elevated temperature under stress is very important for these applications. Thus, improved dimensional stability at higher temperature is of significant economic value. Dimensional stability at higher temperature are typically measured by heat distortion temperature, which is defined as the temperature at which an arbitrary deformation occurs when the test specimens are subjected to an arbitrary level of stress. Nucleating agents are known to increase the heat distortion temperature of polyolefin. Nucleating agents that induce provide improved heat distortion temperatures are thus highly desirable and necessary within certain polyolefin articles. To date, no [2.2.2]dicarboxylate salts have been taught or fairly suggested within the prior art that induce good peak crystallization temperatures, clarity, and high heat distortion temperatures simultaneously within target thermoplastics.
OBJECTS OF THE INVENTION
[0014] Therefore, an object of the invention is to provide a nucleator compound and compositions thereof of the [2.2.2]dicarboxylate salt type that induces excellent high peak crystallization temperatures to polypropylene articles and formulations and also provides improved clarity and heat distortion temperatures in the same articles and formulations. Additionally, it is an object of this invention to provide a nucleator compound or composition that may be used in various polyolefin media for use in myriad end-uses.
[0015] Accordingly, this invention encompasses metal or organic salts of saturated [2.2.2]dicarboxylates, preferably bicyclic dicarboxylates, and most preferably of compounds conforming to Formula (I)
[0016] wherein M 1 and M 2 are the same or different, or M 1 and M 2 are combined to from a single moiety, and are independently selected from the group consisting of metal or organic cations, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , and R 12 are individually selected from the group consisting of hydrogen, C 1 -C 9 alkyl, hydroxy, C 1 -C 9 alkoxy, C 1 -C 9 alkyleneoxy, amine, C 1 -C 9 alkylamine, halogen, phenyl, alkylphenyl, and geminal and vicinal C 1 -C 9 carbocyclic. Polyolefin articles and additive compositions for polyolefin formulations comprising at least one of such compounds are also encompassed within this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] As noted above, in order to develop a proper polyolefin nucleator compound or composition for industrial applications, a number of important criteria needed to be met. The inventive nucleating agents meet all of these important requirements very well. For instance, as discussed in greater detail below, these inventive salts provide high peak crystallization temperatures in a variety of polyolefin formulations, particularly within random copolymer polypropylene (hereinafter RCP) and homopolymer polypropylene (hereinafter HP). As a result, such inventive salts provide excellent mechanical properties for polyolefin articles without the need for extra fillers and rigidifying additives, and desirable processing characteristics such as improved (shorter) cycle time. The salts also show much improved clarity comparing to prior art. Lastly, such inventive salts provide improved heat distortion temperature when comparing to the closest prior art.
[0018] Such properties are highly unexpected and unpredictable, particularly in view of the closest prior art, the WO 98/29494 reference discloses nucleation and clarification additives for polyolefin articles including unsaturated[2.2.2]dicarboxylate salts; however, there is no exemplification of a saturated dicarboxylate salt of this type. The closest embodiment within that art is identified as disodium bicyclo[2.2.2]octene dicarboxylate. After intensive investigations, it has been determined that, quite unexpectedly, as discussed below in greater detail, the hydrogenation of such compounds provides significant improved nucleation efficacy and other properties for the target and inventive thermoplastic (e.g., polyolefin, and the like) compositions. It has now been found that the saturation of Diels-Alder reaction products to form dicarboxylate salts, and in particular, without intending to limit the scope of the invention, saturated bicyclic dicarboxylate salts, provide unforeseen benefits for polyolefin nucleation processes.
[0019] As indicated in Table 1, below, the haze provided target polyolefin articles with these inventive saturated compounds are from about 4 units (4%) lower than that for the related unsaturated compounds. Such improvements are simply unexpected and are unpredictable from any known empirical or theoretical considerations. Furthermore, significant improvements in heat distortion temperature of the saturated compounds were also unexpectedly observed as shown in Table 2, below. Such unpredictable improvements are of great practical significance as discussed before.
[0020] The inventive salts are thus added within the target polyolefin in an amount from about 50 ppm to about 20,000 pm by weight in order to provide the aforementioned beneficial characteristics, most preferably from about 200 to about 4000 ppm. Higher levels, e.g., 50% or more by weight, may also be used in a masterbatch formulation. Optional additives within the inventive salt-containing composition, or within the final polyolefin article made therewith, may include plasticizers, antistatic agents, stabilizers, ultraviolet absorbers, and other similar standard polyolefin thermoplastic additives. Other additives may also be present within this composition, most notably antioxidants, antistatic compounds, perfumes, chlorine scavengers, and the like. Such additives, and others not listed, are well known to those skilled in the art.
[0021] The term polyolefin or polyolefin resin is intended to encompass any materials comprised of at least one polyolefin compound. Preferred examples include isotactic and syndiotactic polypropylene, polyethylene, poly(4-methyl)pentene, polybutylene, and any blends or copolymers thereof, whether high or low density in composition. The polyolefin polymers of the present invention may include aliphatic polyolefin and copolymers made from at least one aliphatic olefin and one or more ethylenically unsaturated co-monomers. Generally, the co-monomers, if present, will be provided in a minor amount, e.g., about 10 percent or less or even about 5 percent or less, based upon the weight of the polyolefin (e.g. random copolymer polypropylene), but copolymers containing up to 25% or more of the co-monomer (e.g., impact copolymers) are also envisaged. Other polymers or rubber (such as EPDM or EPR) may also be compounded with the polyolefin to obtain the aforementioned characteristics. Such co-monomers may serve to assist in clarity improvement of the polyolefin, or they may function to improve other properties of the polymer. Other examples include acrylic acid and vinyl acetate, etc. Examples of olefin polymers whose transparency can be improved conveniently according to the present invention are polymers and copolymers of aliphatic monoolefins containing 2 to about 6 carbon atoms which have an average molecular weight of from about 10,000 to about 2,000,000, preferably from about 30,000 to about 300,000, such as, without limitation, polyethylene, linear low density polyethylene, isotactic polypropylene, syndiotactic polypropylene, crystalline ethylenepropylene copolymer, poly(1-butene), polymethylpentene, 1-hexene, 1-octene, and vinyl cyclohexane. The polyolefin of the present invention may be described as basically linear, regular polymers that may optionally contain side chains such as are found, for instance, in conventional low density polyethylene.
[0022] Although polyolefin are preferred, the nucleating agents of the present invention are not restricted to polyolefin, and may also give beneficial nucleation properties to polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), as well as polyamides such as Nylon 6, Nylon 6,6, and others. Generally, any thermoplastic composition having some crystalline content may be improved with the nucleating agents of the present invention.
[0023] The compositions of the present invention may be obtained by adding the inventive saturated bicyclic dicarboxylic salt (or combination of salts or composition comprising such salts) to the thermoplastic polymer or copolymer and merely mixing the resultant composition by any suitable means. Alternatively, a concentrate containing as much as about 20 percent by weight of the inventive saturated [2.2.2]salt in a polyolefin masterbatch comprising the required acid scavenger may be prepared and be subsequently mixed with the target resin. Furthermore, the inventive compositions (with other additives potentially) may be present in any type of standard thermoplastic (e.g., polyolefin, most preferably) additive form, including, without limitation, powder, prill, agglomerate, liquid suspension, and the like, particularly comprising dispersion aids such as polyolefin (e.g., polyethylene) waxes, stearate esters of glycerin, montan waxes, mineral oil, and the like. Basically, any form may be exhibited by such a combination or composition including such combination made from blending, agglomeration, compaction, and/or extrusion.
[0024] The composition may then be processed and fabricated by any number of different techniques, including, without limitation, injection molding, injection blow molding, injection stretch blow molding, injection rotational molding, extrusion, extrusion blow molding, sheet extrusion, film extrusion, cast film extrusion, foam extrusion, thermoforming (such as into films, blown-films, biaxially oriented films), thin wall injection molding, and the like into a fabricated article.
PREFERRED EMBODIMENTS OF THE INVENTION
[0025] Examples of particularly preferred fluid dispersions within the scope of the present invention are presented below.
[0026] Production of Inventive Salts
EXAMPLE 1
Disodium bicyclo[2.2.2]octane-2,3-dicarboxylate
[0027] To a solution of disodium bicyclo[2.2.1]oct-5-en-2,3-dicarboxylate (10.0 g, from example 3) in water (100 g) was added 0.5 g palladium on activated carbon (5 wt %). The mixture was transferred into a Parr reactor and was subjected to hydrogenation (50 psi, room temperature) for 8 hours. The activated carbon was filtered out. Water is removed in vacuo at 75° C. The resulting product was dried and milled (m.p >300° C.).
EXAMPLE 2 (COMPARATIVE)
Disodium bicyclo[2.2.2]oct-5-en-2,3-dicarboxylate
[0028] To a solution of maleic anhydride (10.30 g) in toluene (100 ml) was added 1,3-cyclohexadiene (8.41 g). The mixture was refluxed for 3 hours. After cooling to 25° C., the solvent was evaporated at reduced pressure. The solid was recrystallized from EtOAC/hexane to yield bicyclo[2.2.2]oct-en-2,3-dicarboxylic anhydride as colorless crystals.
[0029] To a suspension of endo-bicyclo[2.2.1]oct-5-en-2,3-dicarboxylic anhydride (17.8 g, 0.1 mol) in water (100 g) was added sodium hydroxide (8.0 g, 0.2 mol) at room temperature. The mixture was then stirred at 80° C. for 2 hour. A clear, homogeneous solution was obtained. Water was removed in vacuo at 75° C. and the resulting white crystalline product was dried and milled (m.p.>300° C.).
[0030] Other salts of lithium, rubidium, potassium, strontium, barium, and magnesium dicarboxylate salts were prepared in like manners.
[0031] Nucleation Efficacy Test
[0032] Thermoplastic compositions (plaques) were produced comprising the additives from the Examples above and sample homopolymer polypropylene (HP) resin plaques, produced dry blended in a Welex mixer at ˜2000 rpm, extruded through a single screw extruder at 400-450° F., and pelletized. Accordingly, one kilogram batches of target polypropylene were produced in accordance with the following table:
HOMOPOLYMER POLYPROPYLENE COMPOSITION TABLE
[0033] [0033] Component Amount Polypropylene homopolymer (Himont Profax ® 6301) 1000 g Irganox ® 1010, Primary Antioxidant (from Ciba) 500 ppm Irgafos ® 168, Secondary Antioxidant (from Ciba) 1000 ppm DHT-4A, Acid Scavenger as noted Calcium Stearate, Acid Scavenger as noted Inventive Nucleator as noted
[0034] The base HP [having a density of about 0.9 g/cc, a melt flow of about 12 g/10 min, a Rockwell Hardness (R scale) of about 90, a tensile strength of about 4,931 psi, an elongation at yield of about 10%, a flexural modulus of about 203 ksi, an Izod impact strength of about 0.67 ft-lb/in, and a deflection temperature at 0.46 mPa of about 93° C., as well as an expected isotacticity of between about 96 and 99% through xylene solubles analysis] and all additives were weighed and then blended in a Welex mixer for 1 minute at about 1600 rpm. All samples were then melt compounded on a Killion single screw extruder at a ramped temperature from about 204° to 232° C. through four heating zones. The melt temperature upon exit of the extruder die was about 246° C. The screw had a diameter of 2.54 cm and a length/diameter ratio of 24:1. Upon melting the molten polymer was filtered through a 60 mesh (250 micron) screen. Plaques of the target polypropylene were then made through extrusion into an Arburg 25 ton injection molder. The molder was set at a temperature anywhere between 190 and 260° C., with a range of 190 to 240° C. preferred, most preferably from about 200 to 230° C. The plaques had dimensions of about 51 mm ×76 mm ×1.27 mm, and the mold had a mirror finish which was transferred to the individual plaques. The mold cooling circulating water was controlled at a temperature of about 25° C.
[0035] Testing for nucleating effects and other important criteria were accomplished through the formation of plaques of clarified polypropylene thermoplastic resin. These plaques were formed through the process outlined above with the specific compositions listed above in the above Table.
[0036] These plaque formulations are, of course, merely preferred embodiments of the inventive article and method and are not intended to limit the scope of this invention. The resultant plaques were then tested for peak crystallization temperatures (by Differential Scanning Calorimetry). Crystallization is important in order to determine the time needed to form a solid article from the molten polyolefin composition. Generally, a polyolefin such as polypropylene has a crystallization temperature of about 110° C. at a cooling rate of 20° C./min. In order to reduce the amount of time needed to form the final product, as well as to provide the most effective nucleation for the polyolefin, the best nucleator compound added will invariably also provide the highest crystallization temperature for the final polyolefin product. The nucleation composition efficacy, particular polymer peak crystallization temperature (T c ), was evaluated by using a modified differential scanning procedure based upon the test protocol ASTM D3417-99 wherein the heating and cooling rates utilized have been altered to 20° C./minute each. Thus, to measure the peak crystallization temperatures of the samples, the specific polypropylene compositions were heated from 60° C. to 220° C. at a rate of 20° C. per minute to produce molten formulations and held at the peak temperature for 2 minutes. At that time, the temperature was then lowered at a rate of 20° C. per minute until it reached the starting temperature of 60° C. for each individual sample. The important crystallization temperatures were thus measured as the peak maxima during the individual crystallization exotherms for each sample. After allowing the plaques to age for 24 hours at room temperature, haze values were measured according to ASTM Standard Test Method D1003-61 “Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics” using a BYK Gardner Hazegard Plus.
[0037] The following Table lists the peak crystallization temperatures and haze results for the sample plaques prepared with the additives noted above (with certain acid scavengers and levels thereof as well as levels of nucleating agent used therein specified for each sample; Samples 5-10, below included 2500 ppm each of the nucleating agent):
EXPERIMENTAL TABLE 1 Performance of Bicyclic Nucleators in Polypropylene Homopolymer Sample # Nucleator Conc. (ppm) Peak T c (° C.) Haze (%) 1 Example 1 (1000 ppm) a 122.5 35 2 Example 1 (2500 ppm) b 124.1 30 3 Example 2 (1000 ppm) a 122.4 39 4 Example 2 (2500 ppm) b 123.7 35
[0038] The data show that inventive nucleating agents of Example 1 exhibit improved clarity (lower haze) and simultaneous high polymer crystallization temperature comparing to the nucleating agent in example 2.
[0039] Another important test for nucleation efficacy is the heat distortion temperature of the nucleated thermoplastic. Heat distortion is defined as the temperature at which an arbitrary deformation occurs within the thermoplastic when the sample thermopalstic is subjected to an arbitrary level of stress. Data from this test may be used to predict the behavior of plastic materials at elevated temperatures. In a practical sense, a higher heat distortion is indicative of higher dimensional stability at elevated temperature, and therefore, of significant economic value.
[0040] Nucleating agents are known to increase the heat distortion temperature of polyolefin. The degree of enhancement is an indication of nucleation efficacy. The heat distortion measurement was conducted on a Ceast® HDT3 using ASTM Method D648-98c “Standard Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position”. The test specimens were loaded to a fiber stress of 1.82 mPa. The test specimens (plaques) were approximately 127 mm in length, 12.7 mm in depth, and 3.2 mm in width and were made from the same formulations and by the same process as for the Polypropylene Composition listed above. The test data are summarized in the Table below:
EXPERIMENTAL TABLE 2 Heat Distortion Temperature in Homopolymer Loading Sample # (from Experimental Table 1) (ppm) HDT ( C) Control ----- 91.8 Example 2 (Comparative) 1000 106.2 Example 2 (Comparative) 2500 111.3 Example 1 1000 110.9 Example 1 2500 113.2
[0041] The data show that the inventive nucleating agent induces improved heat distortion temperature as compared with the unsaturated nucleating agent of Example 2. This result is unexpected and of significant value to the thermoplastic compounder.
[0042] Having described the invention in detail it is obvious that one skilled in the art will be able to make variations and modifications thereto without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined only by the claims appended hereto. | Compounds of and compositions comprising specific salts of saturated [2.2.2] dicarboxylate in order to provide highly desirable properties within thermoplastic (e.g., polyolefin) articles are provided. The inventive salts and derivatives thereof are useful as nucleating and/or clarifying agents for such thermoplastics, are easy to produce and handle, and relatively inexpensive to manufacture. Such compounds induce high peak crystallization and improved stiffness within thermoplastics. Also, thermoplastic compositions comprising such novel nucleating agents exhibit improved heat distortion properties and clarity levels in comparison with the closest unsaturated salt nucleating agents. Thermoplastic additive compositions and methods of producing thermoplastics with such compounds are also contemplated within this invention. | 2 |
DOCUMENTS INCORPORATED BY REFERENCE
U.S. Pat. No. 3,997,891 is hereby incorporated by reference to illustrate one of the input methods and its practice with which this invention would be useful.
CROSS-REFERENCE TO RELATED APPLICATIONS
The subject matter of this patent application is related to the subject matter of copending patent application Ser. No. 926,928 filed Nov. 3, 1986, U.S. Pat. No. 4,731,609.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to computer-aided design systems, i.e., computer controlled graphics and particularly to computer-aided design applications where one of many drawings, views, patterns, lines, or points can be selected for modification by the user. For purposes of explanation, computer-aided drawings comprise a hierarchy, the top being a drawing, a drawing being comprised of one or more views, a view being comprised of one or more patterns, a pattern being comprised of one or more lines, and lines being defined by points.
An entity is a member of any level in the hierarchy.
The subject matter includes cursor mark position control having a manual means which determines the position and controls particular energization of a display element to which the control by the input means is directed.
2. Description of Related Art
In computer controlled graphics, a cursor is an on-screen symbol used to supply feedback to the user by visually indicating the position and set membership of selected displayed entities. A moveable cursor can be used to select entities for purposes of altering the displayed graphics.
Where many entities appear on the screen, e.g., boxes, circles, nuts and bolts, and polygons, selecting the desired entity by moving a selection device to the proximity of the entity to be identified is not an easy process. The mathematical computations require more time because of the increase in the number of points and lines to be taken into account.
The selection devices for computer-aided design (CAD) applications include styli on digitized tablets, mouse, light pens, or joy sticks. Such devices function to return a set of x,y coordinates that indicate where the selection device specifying the cursor has been positioned with respect to the system of coordinates used in the display system. When trying to select a given point or line with a selection device, it is difficult to place the selection device exactly at the x,y coordinates of the entity to be selected.
Closely spaced entities increase the difficulties of selecting the desired entity. Correlation, as used herein, is the ability to associate a selected x,y coordinate to a screen entity without ambiguity. Existing techniques use mathematical algorithms for calculating whether each individual vector displayed on a graphic screen is correlated to the x,y position returned by an input device. As the number of vectors displayed on the screen increases, the time required to correlate increases proportionately, since more calculations have to be made on more vectors until the correct vector is identified.
When CAD workstations were connected to large main frame processing units, which were very fast, the time required for the calculations was short. Using such CAD applications on smaller processors, such as personal computers, requires longer periods of time for correlation.
A substantial amount of time is required to correlate graphic data on a CRT screen, and when a large amount of geometry is displayed, the correlation calculations use a large amount of time. Complex geometry in many systems cannot be conveniently edited because of the amount of time required. In graphic programs run on personal computers, correlation usually degrades performance of the system.
The invention to be described has a correlation time, independent from the amount of data and provides almost instantaneous correlation of the selected entity, even when used with slow processors. The invention to be described is device independent and can be adapted for CADAM, e.g., trapping.
Low cost raster devices have graphic hardware that are not capable of differentiating between a single line or multiple lines occupying the same end points. Therefore, in the case of multiple lines having the same x,y coordinates of end points, if one line is to be erased, the system cannot determine whether there are lines beneath it, leaving a space where the line should have been. The effect is that the screen does not display the actual information relating to the drawing. To restore the lines beneath a deleted line, the system has to redraw the display, which is a slow process and requires and operator to constantly work with inaccurate information, constantly selecting the redraw operation. The invention eliminates the above described problems.
U.S. Pat. No. 3,997,891 describes a light pen detection system for detecting the character display are on a cathode ray tube (CRT) display. The character near the pen is marked and, if not the desired one, the detection process continues until an indication is provided indicating that the correct character has been detected. The system according to this patent responds to light on the detecting surface of the pen which means that the selected character is the one having a portion thereof at the point on the display where the pen is positioned.
SUMMARY OF THE INVENTION
In accordance with the invention a graphics system for displaying entities from a bit map storing the pels of said entities, including a correlation array for storing tags, each tag associated a separate entity and stored in locations in the array corresponding to the bit map locations occupied by the associated entity, and also having a moveable cursor for selecting a displayed entity by converting the x,y coordinates of the cursor to a location in said correlation array to extract the tag of the selected entity, correlates a part of said selected entity with said cursor selecting whether said part of said selected entity is a line or a point, representing each displayed entity by a command vector stored in a buffer memory, the command vector including the end points of lines comprising the displayed entity, and storing in a file buffer a list of tags identifying the displayed entities cross referencing the buffer memory address of the command vector corresponding to the displayed entity for each tag. The cross referenced address is accessed in said file buffer corresponding to the selected entity and, from the buffer memory, the command vector corresponding to the selected entity is retrieved. The vector includes the x,y coordinates of the end points of the lines comprising the selected entity which are used to calculate an index value corresponding to the distance between the cursor and each selected part of the entity. The selected part thereof having the lowest index value is selected as the desired part of the selected entity.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described in detail by referring to the various figures which illustrate specific embodiments of the invention, and wherein like numerals refer to like elements.
FIG. 1 is a block diagram of a system in which the invention is useful.
FIG. 2 is an illustration of a buffer command entry or vector.
FIG. 3 is an illustration showing the relationship between a cursor and the points defining a polygon.
FIG. 4 is an illustration showing the relationship between two cursors and two line.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 demonstrates a system in which the invention can be utilized and shows the details of interconnections among the various devices and of memory entries.
The input to the system is shown as supplied by a digitizing tablet 101, e.g., commercially available as an IBM Model 5083 II, which supplies signals identifying the x- and y-coordinates of the stylus (or pointer) 102 on the tablet and a select signal which is activated by the operator, e.g., by pushing down on the stylus to activate a switch therein, to signify that a selected point is to be used.
A signal from control unit 110, usually a programmable processor, enables the system to specify a desired sensitivity, i.e., to specify the size of the area around the pointer which should react to the positioning of the pointer.
The display is stored as bits in a screen map 17 which has a bit cell for storing each dot as presented on the screen of a CRT display 16. Normally, if a bit in the screen map 17 is set, i.e., is true, turned on, has a binary value of one, the corresponding point on the screen of the display 16 will be lighted. If a bit in the screen map 17 is reset, i.e., is false, turned off, has a binary value of zero, then the corresponding point on the screen of the display 16 is dark.
When a point is indicated by a moveable cursor, the x,y coordinates of the cursor are to be associated with one of the displayed entities. In this explanation, it will be assumed that the entity selected to be displayed is at the pattern level and that some information as to the selected line or point is also to be determined.
The usual method for associating a cursor point with an entity is to compare the x,y coordinates of the cursor with all the x,y coordinates of the displayed entities. Such a comparison can be expedited by determining whether the cursor's x,y coordinates fall on a line between two points that define a line instead of comparing the coordinates with all the points of the same line. Such calculation is well known in analytic geometry and involves computing the equation of the line associated with its two end points followed by a substitution of x,y values to determine whether the cursor is on the line. Other comparisons are required to ascertain that the cursor is between the two end points since the cursor could be beyond the end points and still fulfill the mathematical requirements for being part of the line.
In the system of the invention, a correlation array 10 or correlation map is stored in the memory of a control unit 110. Each element in the correlation array 10 can correspond to a selectable, unique position on the digitizing tablet and in the screen map 17. The entities to be displayed by the system are identified by a tag, which for purposes of illustration, are decimal numbers. The tag for each entity is stored in the correlation array 10 at a position corresponding to the bits in the screen map 17 that are used by such entity. The cell corresponding to the cursors x,y coordinates, xt,yt, is found to be
cell number=myt+xt
where m is the number of cells per row.
This method provides a fast correlation between a cursor's position and the entity at that position. In such a display system, it is desirable to have high resolution which requires that the screen map 17 have a large capacity. As the number of dots on the display screen, sometimes called pels (picture elements), the ability to place the cursor exactly on an entity becomes more difficult. It also requires that the correlation array 10 be large as well.
To alleviate the last two problems, the correlation array 10 does not have a one-to-one correspondence of cells with pels in the screen map 17. Instead, the correlation array 10 can be arranged to have a cell for each p×q group of pels in the screen map 17. The most useful values of p or q are 2, 4, or 8, but can be other values. The high resolution makes it unlikely that two different entities may occupy the same group of pels. The user, however, has more lee way in the selection of an entity. If the pels are 0.01 mm apart, then a 4×4 cell grouping requires that the cursor be placed now in the 0.01 mm space but in a 0.04 mm space near the entity being selected. The cell in the correlation array 10 corresponding to the p×q group of pels containing the x,y coordinates of the cursor can be determined by
cell number=(yt/p)(m/p)+xt/q.
An entity to be drawn may first be selected from a menu on the screen of display 16 using the digitized tablet 101 and stylus 102 to position the pointer on the display screen 15. When the desired figure is selected, a description of the procedure to draw the selected figure is displayed on the screen. For example, the instructions for drawing a line may comprise selecting each end point defining the line.
In FIG. 1, a line is shown as drawn between selected correlation cells 4 and 2m. The end points were selected, for example, using the digitizing tablet 101 and stylus 102. The selected end points are the x,y coordinates in the screen map 17. The intermediate points can be calculated from the analytic geometry formula for a straight line expressed as two points, i.e.,
(y-y1)/(x-x1)=(y1-y2)/(x1-x2)
where x1,y1 and x2,y2 are the selected end points of the line. (Similar algorithms are available for circles, text, and other forms.) The formula may be used by substituting for x all the intermediate values from x1 to x2 to find the corresponding y intermediate values. These points are converted to memory addresses in the the screen map 17 and the corresponding bits set. At the same time, the corresponding cells in the correlation map can be calculated as explained above and the tag assigned to the entity stored therein. That is, the correlation array cells (or elements) corresponding to the intermediate points are computed and each computed element in the array corresponding to all the points of the line will contain the tag number representing the line stored therein.
Assuming that the-tag of the line in the illustration is assigned the value of 1, then the array elements 4, m+3, m+2, 2m+1, and 2m will store the tag value of 1.
A buffer memory 19 stores command entries in the form illustrated in FIG. 2. Each such entry or command vector has a field for specifying the color of the figure to be displayed. One field contains a command illustrated in FIG. 2 as DRAW contains the x- and y-coordinates of the end points of the vectors making up the entity corresponding to the command entry. The example in FIG. 2 comprises a typical display list structure. An actual structure may be more complicated, but the important point is that, because x,y coordinates are stored in a display list in a simple, low precision format (typically sixteen bits) and because the list is stored in memory, the computations necessary to perform the correlation to a particular point or line can be accomplished extremely fast. After selection, the tag can be used to extract high precision x,y coordinates from a disk-based data base.
In FIG. 1, execution unit 18 converts the vector information to a raster scan format, storing the desired display information in a screen map 17. The display information is bit-mapped from the screen map 17 to the raster scan display unit 16, shown with a line 15 displayed as the vector stored in the correlation map 10.
The control unit 110 also stores an element list 11. For each entity corresponding to a tag, the beginning and ending addresses of the command vector corresponding entity in the buffer memory 19.
A data base is also maintained in the control unit 110 to permit manipulation of the entities at several levels in a hierarchy as described above.
Color fill-ins and cross-hatching of entities can be stored and moved about as separate entities.
FIG. 3 shows a rectangle which can be stored as a command vector as follows:
DRAW x1y1x2y2x3y3x4y4x1y1.
The point xt,yt in FIG. 3 represents the position of a cursor defined by the position of a stylus on a digitized tablet, of a light pen on a CRT display, of a mouse on a surface, and the like.
The cursor is first correlated to an entity. In the illustrated example, it is assumed that the cursor is within n (where n continues to represent the group size of pels) pels of the line from x1,y1 to x2,y2 or of the line from x2,y2 to x3,y3. The entity, i.e., the rectangle 30, will be highlighted on the display screen to indicate that it has been selected.
The computations being described are being continually carried on because the cursor may be in motion. Also, the wrong entity is sometimes selected so the user will move the cursor closer to the desired entity until the desired entity has been selected. Highlighting, i.e., brightening the lines of the entity, is one of the methods of indicating which entity has been selected. Other indications may include linking the lines comprising the selected entity or changing their color.
Besides selecting a desired entity, it may also be desirable to select a given line or a given point within that entity. Therefore, in addition to selecting the desired entity and highlighting it, it is also necessary to select the nearest line or point, whichever has been previously designated by the user. In this illustration, a point will be marked by blinking a marker at the point and a line, by blinking a marker at the center point of the line.
To correlate the cursor to the nearest point, an index value related to the distance of the cursor from each point in the entity being stored and displayed--the rectangle 30 in this illustrative example shown in FIG. B--is calculated and the stored point corresponding to the smallest index value is determined to be the selected point.
In the prior art, the actual distance between the cursor and all other points is calculated using the square root of the quantity (xt-xi) 2 +(yt-yi) 2 .
When the entity has been selected, the element list 11 is accessed and the beginning and ending address of the command vector representing the rectangle 30 in the buffer memory 19 are used to extract the command vector. The four points of representing the entities corners are available from the command vector so retrieved.
The index value for each point xi,yi, where i will range from 1 to 4 in this example, can be calculated by
I=(xt-xi).sup.2 +(yt-yi).sup.2 (1)
where the square root is not necessary because the actual distance is not required, merely a value related to the distance and permits ordering the points according to distance. This reduces the time required to calculate each index.
As illustrated in FIG. 3, the point x2,y2 is closest to the cursor and is, therefore, selected. It is usually emphasized on the display as a brighter portion or highlighted cross on the point. Alternatively, the selected point may be identified by a blinking marker such as a small cross centered on the selected point.
When the closest line is to be selected by the cursor as shown in FIG. 4, a more complicated calculation is required for determining which line of several lines that may be close together on the display is the line to be selected. A calculation of the index value, I, representing a proportional distance value between a line and the cursor is
I=([(y6-y5)xt]+[(x6-x5)yt])/([y6-y5]+[x6-x5]) (2)
A faster result can be derived by performing the subtractions only once instead of twice as equation (2); that is,
A=[yk-yj]
B=[xk/k-xj]
I=([Axt]+[Byt])/(A+B) (3)
where xk,yk and xj,yj are the point pairs that identify each line tested in the display.
When testing for proximity to a line, an additional test is required to verify that the cursor is not correlated to a phantom line such as the extension of a line. In FIG. 4, a dotted line 46 shows an extension of a line defined by the end points x7,y7 and x8,y8. A cursor at the location xt2,yt2 would be incorrectly correlated to the extension line because it is closer thereto than it is to the line with the end points x5,y5 and x6,y6. It is, however, desired to have the cursor xt2,yt2 correlated to the latter line.
Therefore, in addition to performing the index calculations, it is also necessary to perform an additional calculation to insure that a normal line from the cursor will intersect the line being considered between its end points. One approach is to calculate the following values:
M=(y2-y1)/(x2-x1)
X=(x1-xt+M(yt-y1))/2
Y=(y1+yt+M(xt-x10))/2
where M is actually the slope of the line designated by end points x1,y1 and x2,y2. Division by two is easily accomplished in microprocessors by shifting the quantity to be divided one bit position to the right. Error accumulation if y2 is close to y1 or if x2 is close to x1 can be reduced by standard techniques well known in the computer art.
After calculating the values of X and Y, a test is made to insure that X falls between x1 and x2 and that Y falls between y1 and y2. If they do not, then the line is not considered as a candidate and the end point pairs are not stored even though the index value is less than the index value of the previous line.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes and modifications in form and details may be made therein without departing from the spirit and scope of the invention according to the following claims. | Graphics display system having a moving cursor, such as a cursor, for selecting a displayed entity with the capability of determining which one of several lower level entities in the vicinity of the cursor is to be selected. The correlation of a cursor with a entity intended to be selected is performed by calculating an index that does not represent the actual distance, which is time consuming, but rather represents a value, more quickly calculated, such that the size order among the indices is the same as the size order of the distances they represent. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to blends of fluorinated and non-fluorinated thermosetting monomers and resultant cured products used to produce resins with modified surfaces.
2. Description of the Prior Art The fluorinated diol of structure ##STR1## where R f =H or C n F 2n+1 for n=1-18 has proven to be a highly useful intermediate for the production of various thermosetting resins. For example, when reacted with an excess of epichlorohydrin it produces a diglycidyl ether which may be crosslinked with polyfunctional amines to produce a fluorinated epoxy resin (see U.S. Pat. No. 3,879,430). When reacted with a stoichiometric quantity of epichlorohydrin and another diol it produces a fluorinated polyol which may be crosslinked with polyfunctional isocyanates to produce a fluorourethane (see U.S. Pat. No. 3,720,639, U.S. Pat. No. 3,852,222, U.S. Pat. No. 4,157,358, and commonly assigned, co-pending U.S. patent application Ser. No. 277,089, filed Nov. 28, 1988). When reacted with the appropriate acid chloride, it produces a diacrylate or dimethacrylate which may be polymerized to produce the corresponding fluorinated acrylate or methacrylate resin (see U.S. Pat. No. 4,356,296). When the diglycidyl ether of the fluorinated diol is reacted with acrylic acid or methacrylic acid, it produces yet a different diacrylate or dimethacrylate which may be polymerized to fluorinated resins (see commonly assigned co-pending U.S. patent application Ser. No. 263,152, filed Oct. 26, 1988 now U.S. Pat. No. 4,914,171). In other words, the fluorinated diol above may be used as an intermediate to produce a variety of difunctional fluorinated monomers which may be polymerized to produce a variety of fluorinated resins.
The properties of these fluorinated resins are similar to both those of the corresponding non-fluorinated resin and those of a fluoropolymer. In general the thermal and chemical properties of the fluorinated resin are similar to the non-fluorinated material and seem to depend primarily on the chemical linkages produced during polymer formation. On the other hand the fluorinated resins possess a number of properties similar to common fluoropolymers--low moisture absorption, low moisture permeation, low surface energies, low dielectric constants, low index of retraction, low coefficients of friction, and many others--when compared to their non-fluorinated analogues.
The usefulness of the fluorinated resins discussed above depends primarily on their more unique fluoropolymer properties. Application of these resins as oil and water repellents, as biological anti-fouling materials, as marine coatings, as cladding for optical fibers, as low dielectric materials for electronic application, as adhesives, as moisture barrier coatings, as wear reducing agents and many others are possible. In some cases the application of the fluorinated resins depends upon their bulk properties (such as required for electronic and optical applications) and in other cases their application depends on surface properties (such as oil and water repellency or antifouling applications).
For many practical applications the use of the fluorinated resins is restricted by either or both of two factors. First, in order to achieve high levels of fluoropolymer like properties the difunctional monomers used to make the resins must contain fluoroalkyl groups, R f , of significant length (e.g. n=6 to 10). The molecular volume occupied by these groups reduces the cross-link density of the fluorinated resins as compared with many corresponding non-fluorinated resins. As a result, many of the physical properties of the fluorinated materials, such as tensile strength, hardness, glass transition temperature, etc. are reduced when compared with non-fluorinated counterparts. Secondly, the fluorinated resins tend to be quite expensive. The preparation of the basic fluorinated diol intermediate discussed above requires the use of both hexafluoroacetone and perfluorinated alkyl iodide (C n F 2n+1 I) both of which are costly reagents. Many processing steps and material manipulations are required to introduce the perfluoroalkyl group to the diol, and each of these contribute to yield loss in the overall process (see, e.g. U.S. Pat. No. 3,879,430).
For applications of the fluorinated resins which depend upon their bulk properties, it is difficult or impossible to overcome the deficiencies of reduced cross-link density or cost. For applications which depend upon the surface properties of the resins, however, this is not the case. It would be desirable to provide compositions which are characterized as having fluoro-resin surface properties yet provide bulk properties of non-fluorinated resins. It would also be desirable to provide compositions which are characterized as having fluoro-resin surface properties yet which may be produced at greatly reduced costs.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided a composition comprising a blend of at least one functionalized fluorinated monomer with at least one co-reactive non-fluorinated monomer, the fluorinated monomer being derived from compounds of the formula: ##STR2## where R f =H or C n F 2n+1 for n=1-18
Also in accordance with this invention, there is provided a resin obtained by the reactive curing of a composition comprising a blend of at least one co-reactive functionalized fluroinated monomer and at least one co-reactive non-fluorinated monomer, the fluorinated monomer being derived from compounds of the formula ##STR3##
where R f =H or C n F 2n+1 for n=1-18
It has been found that when one of the fluorinated monomers is blended and polymerized with a compatible, co-reactive non-fluorinated monomer, a composition is formed which has the surface characteristics of the fluoro-resin and the bulk characteristic of the non-fluorinated resin.
In the case of urethane resins the fluorinated monomer is comprised of the polyols of structure ##STR4## where X+Y=2-16, X≠0 and where R f =H or C nF2n+1 for n=1-18
and where R is
(a) an aliphatic radical, preferably
--(CH.sub.2).sub.n -- for n=2-8
or --(CH.sub.2 --CHXO).sub.n for n=1-3 and X=H or CH.sub.3,
or (b) an aromatic radical, preferably derived from resorcinol, or bisphenol A.
or (c) a cycloaliphatic radical, preferably derived from cyclohexanediol or cyclohexane-dimethanol.
or (d) a fluorinated radical, preferably a fluorinated aliphatic or aromatic radical of the formula:
--CH.sub.2 (CF.sub.2).sub.3 --CH.sub.2 --
or --CH.sub.2 CH.sub.2 (CF.sub.2 --CF.sub.2).sub.n --CH.sub.2 CH.sub.2 -- for n=1-4 ##STR5##
The non-fluorinated monomer may be one of many common, commercially available polyols, and the urethane resin is produced by reacting the blend of fluorinated and non-fluorinated polyols with a polyisocyanate.
In the case of acrylate resins the fluorinated monomer has the structure ##STR6## where R f =H or C n F 2n+1 for n=1-18 ##STR7## where X is H or CH 3
The non-fluorinated monomer may be one of many common commercially available acrylate or methacrylate monomers, and the acrylate resin is produced by polymerizing the blend of fluorinated and non-fluorinated monomers with heat or light in the presence of a free radical initiator, or other conventional curing procedure.
In the case of epoxy resins the fluorinated monomer has the structure ##STR8## where R f =H or C n F 2n+1 for n=1-18 and R has the structure ##STR9## where R' is a lower aliphatic (e.g., 2 to 6 carbon atoms) or aromatic (e.g., 6 to 12 carbon atoms) radical such as ethylene or toluene or is derived from one of many common polyfunctional amines. The non-fluorinated monomer may be one of many common, commercially available epoxides, and the epoxy resin is produced by thermally curing the blend of fluorinated and non-fluorinated monomers with one of any common epoxy curing agents such as an amine, anhydride, or homopolymer catalytic agent.
The use of many other functionalized monomers derived from the above fluorinated diol are considered within the scope of this invention. This fluorinated diol above may be derivatized to form fluorinated monomers possessing allylic, vinyl ether, styrenic, or other functional groups. These fluorinated monomers may be blended and polymerized with other compatible. co-reactive non-fluorinated monomers to produce compositions having fluoro-resin surface characteristics.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As monomers, the functionalized derivatives of the diol ##STR10## where R f =H or C n F 2n+1 for n=1-18 such as the epoxides, acrylates, and polyols are unique in that their high fluorine content provides them a surface active characteristic. In many regards these materials can be considered to be "surfactant monomers". When cured or polymerized as neat monomers they produce fluoro-resins with many of the physical properties of common fluoropolymers. When blended and cured from the liquid phase with non-fluorinated monomers their surface active characteristic causes them to segregate at the resin surface and hence provide fluoro-resin surface properties.
A "surfactant monomer" may be defined as a material which will reduce the surface or interfacial tension of the liquid phase of a co-reactive monomer system. In this regard the surfactant monomer is analogous to soap in a soap/water solution. For thermodynamic reasons some of the surfactant segregates to the liquid surface of the mixture and the total system energy is reduced. When the monomer system is cured or polymerized, the surfactant monomer is reacted with the co-reactive monomer and is bound at the surface of the solid resin that is produced.
Several criteria seem to be important for a surfactant monomer to perform its function. It must be solubilized in the liquid phase with the co-reactive monomer and must be sufficiently mobile from a diffusional point of view to allow for its segregation at the liquid surface. It must not phase separate or become dispersed from the co-reactive monomer during cure. If it is not soluble in the liquid phase, but only dispersed, a two phase resin system would be formed on curing and the fluorinated monomer would not preferentially be at the surface of the cured resin.
As used herein, the term "co-reactive" means that the monomer contains the same or compatibly reactive radical groups with the other monomer.
The blends and resins of this invention preferably comprise about 0.01 to about 25% by weight of the fluorinated monomer, more preferably about 0.01 to about 10% by weight of the fluorinated monomer, and most preferably, about 0.1 to about 3% by weight of the fluorinated monomer. The blends and resins may be produced by any conventional procedure.
Functionalized monomers derived from the fluorinated diol above may be regarded as surfactant monomers. Their high fluorine content, particularly for preferred structures where the fluoroalkyl group is C 6 F 13 --or C 8 F 17 --, provides them with surfactant characteristics. Reactive, solubilized derivatives which will not separate on curing may be synthesized for most co-reactive monomers. Resins produced from blends of the fluorinated surfactant monomer with co-reactive non-fluorinated monomers have fluoropolymer surface characteristics and demonstrate all the properties associated with low energy surfaces. In addition, the present blends and resins can be produced at significantly lower costs than an all-fluorinated system, These and other benefits of the fluorinated surfactant monomer will become apparent in the following non-limiting examples.
EXAMPLE 1
In Example 1 the effect of a fluorinated polyol on the surface tension of a solution of a non-fluorinated polyol is demonstrated. The fluoropolyol (I) was prepared by the method of U.S. Pat. No. 3,720,639 and had a number average molecular weight of 6600 and a hydroxyl content of 1.45 meq/g. ##STR11##
Blends of (I) with Desmophen 800, a solvent-free, saturated polyester polyol with a hydroxyl number of 290 available from Mobay Chemical were prepared by mixing the components together at room temperature, such that the total polyol content was 50 or 75 wt % in methyl isobutylketone (MIBK) solution. The surface tensions of these solutions were determined by the Wilhelmy balance method, and the results are presented in Table 1.
TABLE 1______________________________________ Surface Energy.sup.(2) (dyne/cm)Wt % Fluoropolyol.sup. (1) 50% Solids 75% Solids______________________________________0 25.5 30.61 23.1 24.55 22.5 24.3100 22.7 --______________________________________ .sup.(1) Wt % fluoropolyol based on total polyol content .sup.(2) Surface tension for MIBK solution with total polyol contents of 50 and 75%, respectively.
The rapid drop in surface tension is indicative of the surface activity of the fluorinated polyol and implies its concentrated presence at the surface.
EXAMPLE 2
In Example 2 the effect of fluorinated polyols on the surface energy of a urethane resin is demonstrated. In this example the blend of fluorinated and non-fluorinated polyols from Example 1 were crosslinked with Desmodur N75, an aliphatic diisocyanate available from Mobay Chemical with a functional equivalent weight of 254, using dibutyltin dilaurate as a catalyst. The polyols, isocyanate, and catalyst were mixed in MIBK solution and were dipcoated and air dried on a glass slide. The surface energy of the cured, dried resin was determined by the critical surface tension method. The atom percent fluorine on the surface was determined by X-ray Photoelectron Spectroscopy (ESCA). The results are presented in Table 2.
TABLE 2______________________________________ Surface Energy Atom % FWt % Fluoropolyol.sup. (1) (Ergs/cm.sup.2) at Surface______________________________________0 35 0.03 22 34.4.05 22 39.31.00 22 41.32.00 22 41.210.00 22 41.5100.00 22 41.5______________________________________ .sup.(1) Weight percent of total polyol content
Comparing this data with that of Example 1 indicates that at low concentrations of fluoropolyol in the solution mixture of polyols, isocyanate and catalyst, the fluoropolyol is driven to the surface due to the surface active nature of the C 8 F 17 group. As solvent evaporates and the resin begins to cure, the fluorinated polyol remains concentrated at the surface and becomes bound to the bulk non-fluorinated polyol. Based on atom percent fluorine at the surface and on the surface energy measurement, it would appear that the surface is nearly 100% fluorourethane, as would be produced by curing neat fluoropolyol with the same isocyanate. This is surprising in that such results are achievable with only about 0.03% of the fluorinated monomer.
EXAMPLE 3
In Example 3 the effect of various fluoropolyols on the surface energy of urethane resins is demonstrated. The oil and water repellancy of these resins as determined by contact angle measurement is also indicated. In this example the fluoropolyols of Table 3 were prepared either by the method of U.S. Pat. No. 3,720,639 or U.S. Pat. No. 3,852,222. Polyols in this table have the structure: ##STR12##
TABLE 3______________________________________Polyol No. R.sub.1 R.sub.2______________________________________II R.sub.3 R.sub.4III R.sub.3 CH.sub.2 (CF.sub.2).sub.3 CH.sub.2IV R.sub.3 (CH.sub.2).sub.4V R.sub.3VI R.sub.4 (CH.sub.2).sub.4VII ##STR13## (CH.sub.2).sub.4 ##STR14##and ##STR15##______________________________________
Each of the polyols of Table 3 was blended with Desmophen 650A, a 65% solids polyester polyol available from Mobay in MIBK solution. These blends were then mixed with Desmodur N75 and dibutylin dilaurate and the resultant solution dip coated on glass slides and air dried and cured to form a urethane resin. The contact angles of water and mineral oil and the surface energies of these resins are shown in Table 4.
TABLE 4______________________________________Polyol Wt. %.sup.(1) Surface Energy Contact Angle (°)No. Polyol (dyne/cm) Water Oil.sup.(2)______________________________________II 0 43 70 18 1 21 85 49 3 18 75 57 5 18 81 62III 1 18 86 57IV 1 18 86 89V 1 17 83 63VI 1 23 78 42VII 1 32 70 21______________________________________ .sup.(1) Weight percent of total polyol content .sup.(2) Nujol oil
As indicated in Example 3, the addition of Polyol II to the non-fluorinated system causes a dramatic decrease in the surface energy of the urethane resin produced. Simultaneously, the surface became non-wetted by both water and oil. For Polyols II, III, IV, and V, all of which have relatively high fluorine content, the impact on surface properties at 1% loading is substantial. The oil and water repellancy produced by these materials is considerable. Even for Polyol VI, which has less fluorine, the impact is significant. For a polyol of similar structure, but with no fluorine (Polyol VII), impact on surface properties is minimal or non-existent.
EXAMPLE 4
Example 4 demonstrates that the surface activity of the fluorinated surfactant monomers is not restricted to just a resin/air surface but that it is sensitive to the resin interface with any low energy surface. In this example the blend of fluorinated polyol, non-fluorinated polyol and isocyanate of Example 2 was used to dip coat both a glass slide and a polytetrafluoroethylene (PTFE) thin plate. After cure and dry, the coating was peeled from the substrate and the fluorine content of all resin interface surfaces was determined by ESCA with the following results presented in Table 5.
TABLE 5______________________________________ Atom % F @Substrate Air Interface Substrate Interface______________________________________Glass 41.2 0.0PTFE 41.3 53.1______________________________________
As indicated the fluorine content is high for both air interfaces and for the resin surface produced against PTFE. This latter observation implies a high degree of wetting of the low energy PTFE surface by the fluoropolyol. Conversely, the fluorourethane does not wet the high energy glass surface, and this interface is more stable to the presence of the non-fluorinated polyol.
EXAMPLE 5
This example shows the effect of a fluorinated acrylate surfactant monomer on the surface tension of a non-fluorinated liquid acrylate and on the surface energy of cured resins produced from this acrylate mixture.
The fluoroacrylate: ##STR16## was prepared by the addition of acrylic acid to the corresponding diglycidyl ether material. (See co-pending U.S. patent application Ser. No. 263,152). This fluorinated acrylate is totally miscible with conventional, non-fluorinated acrylates such as trimethylolpropane tri-acrylate (TMPTA) and mixtures of these materials may be directly cured by electron beam at 3 megarads or by UV light (using 2,2-diethoxyacetophenone as a photoinitiator) to produce clear, glossy coatings. Table 5 shows both the surface tension of the liquid mixtures prior to cure and the surface energy of the cured coatings.
TABLE 5______________________________________ Surface Tension Surface Energy Liquid Mixtures Cured CoatingWt. % Fluoropolyol (dyne/cm) (erg/cm.sup.2)______________________________________0 40.0 370.05 38.2 29.40.10 37.5 22.40.50 34.2 --1.00 32.3 19.45.00 28.5 19.2______________________________________
As was the case with fluoropolyol solutions and the urethane resins, the impact of fluoroacrylates on both surface tension and surface energy is non-linear. It would appear that the fluorinated monomer is concentrated at the liquid mixture surface and is bound there when cured.
EXAMPLE 6
Example 6 shows the effect of a fluorinated amine surfactant monomer on the surface properties of an epoxy resin. The fluorinated amine ##STR17## was prepared by the addition of ethylene diamine to the corresponding fluorinated diglycidyl ether. A 50% solution of this material in isopropyl alcohol was blended with the diglycidyl ether of bisphenol A to form a clear liquid phase. Mixtures of these materials were thermally cured (50° C. for 16 hours) with the appropriate molar equivalent quantity of ethylenediamine to form epoxy resins. Surface energies and water and oil contact angles for these resins are shown in Table 6.
TABLE 6______________________________________ Surface Energy Contact Angle (°)Wt. % Fluoroepoxide.sup.(1) (erg/cm.sup.2) Water Oil______________________________________0 36 42 221.0 20 66 452.5 19 54 535.0 20 57 53100.0 18 80 50______________________________________ .sup.(1) Fluorinated diglycidyl ether as weight percent of total diglycidyl ether content.
As with the other resin systems, the fluorinated surfactant monomer causes the surface energy of the resin to be reduced and produces surfaces which are increasingly oil and water repellant.
Even a fluorinated diglycidyl ether of relatively low fluorine content may impact surface properties. The diglycidyl ether ##STR18## may be blended directly with the diglycidyl ether of bisphenol A and may be cured thermally with ethylene diamine. The surface energies of such mixtures are shown in Table 7.
TABLE 7______________________________________ Surface EnergyWt. % Fluoroepoxide.sup.(1) (erg/cm.sup.2)______________________________________0 361.0 335.0 32100.0 28______________________________________ .sup.(1) Fluorinated diglycidyl ether as weight percent of total diglycidyl ether content.
As with the other resin systems, the surface energy is a non-linear function of fluorinated surfactant monomer content. | A novel class of fluorinated surfactant monomers which when blended and cured with conventional non-fluorinated monomers produces resins with dramatically modified surfaces. Resins which may be thus modified include urethanes, epoxides, acrylates, polyesters and other thermosetting materials. | 2 |
[0001] This application claims priority to the following US Patent Applications: U.S. application Ser. No. 14/326,836 filed Jul. 9, 2014 and U.S. Ser. No. 61/860,293 filed Jul. 31, 2013.
FIELD OF THE INVENTION
[0002] This invention is directed to a polymer thick film white reflective flexible dielectric composition. Dielectrics made from the composition can be used in various electronic applications to protect electrical elements and particularly to provide reflectance to maximize LED lighting.
BACKGROUND OF THE INVENTION
[0003] Dielectrics have long been used to protect electrical elements. They have also been used as isolating layers. Although they have been used for years in these types of applications, the use of dielectrics as reflective elements is not common. This is particularly important in circuits containing LED lighting where one wants to maximize the available brightness through reflectivity. Additionally, more and more circuitry is being developed where the base substrate that the LED's are attached to needs to be bent and shaped in a non-planar fashion. Thus, the white reflective dielectric must also be flexible i.e., it must withstand a 90 degree bend with no cracking. One of the purposes of this invention is to alleviate this issue and produce a flexible reflective construction in which the light generated from LED's can be maximized.
SUMMARY OF THE INVENTION
[0004] This invention relates to a polymer thick film white reflective flexible dielectric composition comprising:
(a) 15-50 wt % of a first organic medium comprising 10-50 wt % urethane resin dissolved in 50-90 wt % first organic solvent, wherein the weight percent of the urethane resin and the first organic solvent are based on the total weight of the first organic medium; (b) 15-50 wt % of a second organic medium comprising 10-50 wt % thermoplastic phenoxy resin dissolved in 50-90 wt % second organic solvent wherein the weight percent of the thermoplastic phenoxy resin and the second organic solvent are based on the total weight of the second organic medium; and (c) 1-70 wt % of a white reflective powder;
wherein the weight percent of the first organic medium, the second organic medium and the white reflective powder are based on the total weight of the composition.
[0008] The invention is further directed to using the white reflective flexible dielectric to form a protective and/or insulating layer in electrical circuits.
DETAILED DESCRIPTION OF INVENTION
[0009] The invention relates to a polymer thick film white reflective flexible dielectric composition for use in electrical circuits.
[0010] The substrate commonly used in the types of circuits considered here is usually polyimide or a polyimide laminate construction such as DuPont™ CooLam® (DuPont Co., Wilmington, Del.). DuPont™ CooLam® is used for thermal conductivity purposes when high-brightness LED's are present. Further, DuPont™ CooLam® 3D (DuPont Co., Wilmington, Del.) is used for circuits which are non-planar.
[0011] The polymer thick film white reflective flexible dielectric composition can also be used in thermoforming electrical circuits, e.g., capacitive switch circuits. The substrate commonly used in polymer thick film thermoformable capacitive circuits is polycarbonate (PC). PC is generally preferred since it can be readily thermoformed. However, PC is very sensitive to the solvents used in the layers deposited on it. An inappropriate solvent can and will cause cracking or crazing in the PC substrate. In the course of producing a 3-dimensional capacitive circuit, after the thermoforming step, the final step will often be a molding step in which the finished circuit is formed by injection molding using a resin such as polycarbonate. This process is referred to as in-molding and involves higher temperatures. Depending on the resin chosen, these temperatures can typically exceed 250° C. for 10-30 sec. Thus the choice of the resins used in the PTF composition is critical. The combination of the resins used in the instant PTF composition has been shown to survive the in-mold process and produce fully functional circuitry whereas most resins typically used in PTF compositions will not.
[0012] The polymer thick film (PTF) white reflective flexible dielectric composition is comprised of (i) two organic mediums comprising two polymer resins dissolved in a first organic solvent and a second organic solvent, respectively, and (ii) white reflective powder. Additionally, powders and printing aids may be added to improve the composition. Herein weight percent will be written as wt %.
Organic Medium
[0013] The first organic medium is comprised of a urethane elastomer resin dissolved in a first organic solvent. The urethane resin must help achieve good adhesion to the underlying substrate. The urethane elastomer must also provide flexibility for the required bending of the circuit. It must be compatible with and not adversely affect the performance of the electrical element.
[0014] In one embodiment the urethane resin is 10-50 wt % and the first organic solvent is 50-90 wt % of the total weight of the first organic medium. In another embodiment the urethane resin is 25-45 wt % and the first organic solvent is 55-75 wt % of the total weight of the first organic medium. In still another embodiment the urethane resin is 15-25 wt % and the first organic solvent is 75-85 wt % of the total weight of the first organic medium. In one embodiment the urethane resin is a urethane elastomer. In another embodiment urethane resin is a polyester-based copolymer.
[0015] The second organic medium is composed of a phenoxy resin dissolved in a second organic solvent that may be the same as the first organic solvent. Different solvents may also be used. The phenoxy resin adds high temperature capability to the composition which aids in the use of this dielectric as a solder mask if required, and also improves moisture permeability. That is, it helps impede the progress of moisture through the composition. In one embodiment the phenoxy resin is 10-50 wt % and the second organic solvent is 50-90 wt % of the total weight of the second organic medium. In another embodiment the phenoxy resin is 20-35 wt % and the second organic solvent is 65-80 wt % of the total weight of the second organic medium.
[0016] In one embodiment, each medium is 15-50 wt % based on the total weight of the composition. In another embodiment, each medium is 15-40 wt % based on the total weight of the composition. In still another embodiment, the first organic medium is 15-25 wt % and the second organic medium is 25-45 wt % based on the total weight of the composition.
[0017] Although the preparation of two separate organic media are preferred, if the same solvent is to be used for both media a single organic medium equivalent to the two organic media described above may be used.
[0018] The polymer resin is typically added to the organic solvent by mechanical mixing to form the medium. Solvents suitable for use in the polymer thick film composition are recognized by one of skill in the art and include acetates and terpenes such as carbitol acetate and alpha- or beta-terpineol or mixtures thereof with other solvents such as kerosene, butyl carbitol, butyl carbitol acetate, hexylene glycol and high boiling alcohols and alcohol esters. In addition, volatile liquids for promoting rapid hardening after application on the substrate may be included. In many embodiments of the present invention, solvents such as glycol ethers, ketones, esters and other solvents of like boiling points (in the range of 180° C. to 250° C.), and mixtures thereof may be used. Various combinations of these and other solvents are formulated to obtain the viscosity and volatility requirements desired. The solvents used must solubilize the resin.
White Reflective Powder
[0019] The white reflective powder includes such powders as titanium dioxide, barium titanate, alumina, or mixtures thereof. In one embodiment, the amount of white reflective powder is 1-70% of the total weight of the entire composition. In another embodiment the white reflective powder is 20-60 wt % of the total weight of the entire composition and in still another embodiment the white reflective powder is 30-55 wt % of the total weight of the entire composition. In one embodiment the powder is titanium dioxide.
[0020] It is preferable to keep the particle size of the reflective powder in the range of 0.3-5 microns so as to avoid any cracking issues.
Additional Powders
[0021] Various powders may be added to the PTF dielectric composition to improve adhesion, modify the rheology and increase the low shear viscosity thereby improving the printability. One such powder is fumed silica where it has been found to significantly improve the resistance to moisture penetration.
Application of the PTF White Reflective Flexible Dielectric Composition
[0022] The PTF white reflective flexible dielectric composition, also referred to as a “paste”, is typically deposited on a substrate, such as polyimide or a laminate of polyimide, such as DuPont™ CooLam® 3D, that is somewhat impermeable to gases and moisture. In other constructions, the white reflective flexible dielectric may be deposited over an existing silver/dielectric construction.
[0023] The deposition of the PTF white reflective flexible dielectric composition is performed typically by screen printing, but other deposition techniques such as stencil printing, syringe dispensing or coating techniques can be utilized. In the case of screen-printing, the screen mesh size controls the thickness of the deposited thick film.
[0024] Generally, a thick film composition comprises a functional phase that imparts appropriate functional properties to the composition. The functional phase comprises functional powders dispersed in an organic medium that acts as a carrier for the functional phase. Generally, the composition is fired to burn out both the polymer and the solvent of the organic medium and to impart the electrically functional properties. However, in the case of a polymer thick film, the polymer portion of the organic medium remains as an integral part of the composition after drying.
[0025] The PTF white reflective flexible dielectric composition is processed for a time and at a temperature necessary to remove all solvent. For example, the deposited thick film is dried by exposure to heat at 130° C. for typically 10-15 min.
Circuit Construction
[0026] The substrate used is typically polyimide-based as further processing steps involve exposure to soldering temperatures. The white reflective flexible dielectric is printed and dried as per the conditions described above. Several layers can be printed and dried. A subsequent step which may include bending of the entire unit is typical in the production of 3D circuits with as much as a 90 degree bend required. In one embodiment, the circuit is used as a solder mask.
EXAMPLE AND COMPARATIVE EXPERIMENT
Example 1
[0027] The PTF white reflective flexible dielectric composition was prepared in the following manner. The first organic medium was prepared by mixing 20.0 wt % Desmocoll 540 polyurethane (Bayer MaterialScience LLC, Pittsburgh, Pa.) with 80.0 wt % dibasic esters (DuPont Co., Wilmington, Del.) organic solvent. The molecular weight of the resin was approximately 40,000. This mixture was heated at 90° C. for 1-2 hours to dissolve all the resin. The second organic medium was prepared by adding 27.0 wt % PKHH (phenoxy) resin (InChem Corp.) to 73.0 wt % dibasic esters and heating as above. The above weight percent are based on the total weight of each of the media, respectively. All following weight percent are based on the total weight of the PTF white reflective flexible dielectric composition. 40.0 wt % titanium dioxide powder (DuPont Co., Wilmington, Del.) was then added as the white reflective powder and the entire composition was mixed. The composition was then subjected to the three-roll-mill for two cycles at 150 psi.
[0028] The composition, based on the total weight of the composition, was:
[0000]
25.0 wt %
First Organic Medium
35.0 wt %
Second Organic Medium
40.0 wt %
Titanium Dioxide Powder
[0029] A circuit was then fabricated as follows: On a DuPont™ CooLam® 3D substrate, a blanket print of the white reflective flexible dielectric composition prepared as described above was printed with a 200 stainless steel screen and dried at 130° C. for 10 min. A second print of the composition was then printed and dried. The part was inspected and no evidence of crazing or deformation of the underlying substrate was found. The circuit was then subjected to a 90 degree bend and tested for cracking/adhesion. No visible signs of cracking were detected, and adhesion before and after the bend was outstanding (5B on ASTM Tape Test). Reflectivity was measured at 90%.
Comparative Experiment A
[0030] A circuit was produced exactly as described in Example 1. The only difference was that the white reflective flexible dielectric composition was not used. Instead, a standard PTF dielectric, DuPont 5036 (DuPont Co., Wilmington, Del.), was used. Here, cracking and adhesion loss was observed after the 90 degree bending. Additionally, reflectivity was only 30%. | This invention is directed to a polymer thick film white reflective flexible dielectric composition comprising urethane resin, thermoplastic phenoxy resin, and white reflective powder. Dielectrics made from the composition can be used in various electronic applications to protect electrical elements and particularly to reflect light in 3D circuits containing LED's. | 5 |
TECHNICAL FIELD
[0001] The presently preferred embodiment of the innovations described herein relate generally to URI redirect methods. More specifically, the presently preferred embodiment relates to time-sensitive URI mapping.
BACKGROUND
[0002] Much of the Internet today is characterized by the World Wide Web, or Web for short. The Web is based on an idea of a uniform syntax for global identifiers of network-retrievable documents, referred to as “document names”, “Web addresses” and “Uniform Resource Locators.” Uniform Resource Locators, or URLs, is misleading, since not all identifiers are locators, and even for those that are, it is not the defining characteristic. By the time the RFC 1630 formally defined the term Uniform Resource Identifier (or URI) as a generic term best suited for the concept, the term “URL” gained widespread popularity, and is a synonym for URI. A typical URI is in the form of:
http://example.com:8080/cgi-bin/animal?species=bird#Texas
where “http://” is the scheme, “example.com” is the host, “8080” is the port (a port of 80 is used if no port is included in the URI), “/cgi-bin/animal” is the path, “species?bird” is the query, and “Texas” is the fragment.
[0004] Typically, host, port, and path remain constant for any given web application, and users of the Web rely on the static location of web pages for Internet enjoyment. Consequently, those users will identify a frequently visited URI by adding a bookmark to their browser for easy return, where the bookmark identifies the URI of the particular page. As the Web evolves, so do web applications that might require the modification of any part of the URI, e.g., the host, port or the path. If the user accesses a web page via a bookmarked location, the user will be disappointed if the information at that location has changed without proper notification.
[0005] Luckily, redirection techniques to send the user from the old URI to the new URI are available when an intentional move is properly identified. Two of the most common techniques are use of the HTML meta refresh tag and use of the HTTP Status Code 301 . In the first technique, the HTTP response header contains the following:
<META http-equiv=“refresh” content=“WAIT_TIME;URL=NEW_URL”>
The body of the response page can contain any normal HTML and that HTML will be displayed by the user's agent/browser. When the user's browser reads this META tag, it will wait for the duration of WAIT_TIME and display the returned HTML. After the expiration of WAIT_TIME, the user browser automatically requests the URI specified in NEW_URL. The advantage with this technique, is the user can read any information coded into the response body before the expiration of WAIT_TIME. The disadvantage, though, is over the past few years the use of the META tag refresh has been abused by spammers and phishers to confuse visitors about which web site they are visiting.
[0007] In the second technique, the browser is sent a HTTP Status Code 301 that corresponds to “Resource Moved Permanently.” The new location is specified in the HTTP “location” header, using PHP for example,:
<? header(“HTTP/1.1 301 Moved Permanently”); header(“Status: 301 Moved Permanently”); header(“Location: http://www.new-url.com”); ?>
[0013] When such a response is received, the user agent will make a request to the URI specified in the Location header. The advantage with this technique is two fold. First the redirect to the new URI is automatic, so it is transparent to the user. Second search engines properly index URIs redirected by this method rather than being potentially de-indexed for using the META tag refresh technique, discussed above. The act of de-indexing a URI from various search engines ensures that that URI will not resolve following a search request. The disadvantage with this second technique, however, is that there is no notification to the user that the page has been moved and to re-set the bookmark to the desired information. Consequently, the user will continue to go to the redirected URI via the 301 redirect technique until the 301 redirect is completely removed resulting in a 404 error—page not found—response to the user.
[0014] What is needed is a method that combines the two mentioned redirect techniques that (1) provides the user with a redirect notification for a period of time, and (2) automatically redirects the user following the expiration of the time period.
SUMMARY
[0015] To achieve the foregoing, and in accordance with the purpose of the presently preferred embodiment as broadly described herein, the present application provides a method for supporting legacy URIs, comprising the steps of receiving a request for a data; initializing said request with at least an expiration identifier; determining a redirection type based on a current date, comprising the steps of if said current date is less than said expiration identifier, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier, then use a status code redirect; mapping said URI to a redirect-URI. The method, wherein said data is in the form of a uniform resource identifier. The method, wherein said expiration identifier is a date. The method, wherein said expiration identifier is a special format. The method, wherein said expiration identifier is one of a date or a special format. The method, further comprising the step of determining a redirection type based on a special format, comprising the steps of: if said special format is NOW, then use a status code redirect; and if said special format is NEVER, then use a meta tag redirect.
[0016] Another advantage of the presently preferred embodiment is to provide a method of supporting legacy URIs, comprising the steps of: receiving a request for a uniform resource identifier; initializing said request with at least an expiration identifier, wherein said expiration identifier is one of a date, NOW, and NEVER; determining a redirection type based on a current date, comprising the steps of: if said current date is less than said expiration identifier or equal to NEVER, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier or equal to NOW, then use a status code redirect; mapping said URI to a redirect-URI.
[0017] And another advantage of the presently preferred embodiment is to provide a method of supporting legacy resource locations, comprising the steps of: initializing a request for a resource location with at least an expiration; determining a redirection type based on a criteria, comprising the steps of; if said criteria is less than said expiration, then use a first redirect; and if said criteria is greater than or equal to said expiration, then use a second redirect; and mapping said resource location to a redirect resource location.
[0018] Yet another advantage of the presently preferred embodiment is to provide a computer-program product tangibly embodied in a machine readable medium to perform a method of supporting legacy URIs, comprising: instructions for receiving a request for a data; instructions for initializing said request with at least an expiration identifier; instructions for determining a redirection type based on a current date, comprising instructions for: if said current date is less than said expiration identifier, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier, then use a status code redirect; instructions for mapping said URI to a redirect-URI. The computer-program product, wherein said data is in the form of a uniform resource identifier. The computer-program product, wherein said expiration identifier is a date. The computer-program product, wherein said expiration identifier is a special format. The computer-program product, wherein said expiration identifier is one of a date or a special format. The computer-program product, further comprising instructions for the step of determining a redirection type based on a special format, comprising instructions for: if said special format is NOW, then use a status code redirect; and if said special format is NEVER, then use a meta tag redirect.
[0019] Still another advantage of the presently preferred embodiment is to provide a computer-program product tangibly embodied in a machine readable medium to perform a method of supporting legacy URIs, comprising: instructions for receiving a request for a uniform resource identifier; instructions for initializing said request with at least an expiration identifier, wherein said expiration identifier is one of a date, NOW, and NEVER; instructions for determining a redirection type based on a current date, comprising instructions for: if said current date is less than said expiration identifier or equal to NEVER, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier or equal to NOW, then use a status code redirect; instructions for mapping said URI to a redirect-URI.
[0020] And yet another advantage of the presently preferred embodiment is to provide a computer-program product tangibly embodied in a machine readable medium to perform a method of supporting legacy resource locations, comprising: instructions for initializing a request for a resource location with at least an expiration; instructions for determining a redirection type based on a criteria, comprising instructions for; if said criteria is less than said expiration, then use a first redirect; and if said criteria is greater than or equal to said expiration, then use a second redirect; and instructions for mapping said resource location to a redirect resource location.
[0021] And still another advantage of the presently preferred embodiment is to provide a data processing system having at least a processor and accessible memory to implement a method for supporting legacy resource locations, comprising: means for receiving a request for a data; means for initializing said request with at least an expiration identifier; means for determining a redirection type based on a current date, comprising the steps of: if said current date is less than said expiration identifier, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier, then use a status code redirect; means for mapping said URI to a redirect-URI.
[0022] Other advantages of the presently preferred embodiment will be set forth in part in the description and in the drawings that follow, and, in part will be learned by practice of the presently preferred embodiment. The presently preferred embodiment will now be described with reference made to the following Figures that form a part hereof. It is understood that other embodiments may be utilized and changes may be made without departing from the scope of the presently preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] A presently preferred embodiment will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and:
[0024] FIG. 1 is a flowchart of a system and method for time-sensitive URI mapping;
[0025] FIG. 2 is a flow chart of the URI mapping and redirection techniques disclosed in the presently preferred embodiment; and
[0026] FIG. 3 is a block diagram of a computer environment in which the presently preferred embodiment may be practiced.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiments. It should be understood, however, that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. The presently preferred embodiment provides, among other things, a system and method of time-sensitive URI mapping. Now therefore, in accordance with the presently preferred embodiment, an operating system executes on a computer, such as a general-purpose personal computer. FIG. 3 and the following discussion are intended to provide a brief, general description of a suitable computing environment in which the presently preferred embodiment may be implemented. Although not required, the presently preferred embodiment will be described in the general context of computer-executable instructions, such as program modules, being executed by a personal computer. Generally program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implementation particular abstract data types. The presently preferred embodiment may be performed in any of a variety of known computing environments.
[0028] Referring to FIG. 3 , an exemplary system for implementing the presently preferred embodiment includes a general-purpose computing device in the form of a computer 300 , such as a desktop or laptop computer, including a plurality of related peripheral devices (not depicted). The computer 300 includes a microprocessor 305 and a bus 310 employed to connect and enable communication between the microprocessor 305 and a plurality of components of the computer 300 in accordance with known techniques. The bus 310 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The computer 300 typically includes a user interface adapter 315 , which connects the microprocessor 305 via the bus 310 to one or more interface devices, such as a keyboard 320 , mouse 325 , and/or other interface devices 330 , which can be any user interface device, such as a touch sensitive screen, digitized pen entry pad, etc. The bus 310 also connects a display device 335 , such as an LCD screen or monitor, to the microprocessor 305 via a display adapter 340 . The bus 310 also connects the microprocessor 305 to a memory 345 , which can include ROM, RAM, etc.
[0029] The computer 300 further includes a drive interface 350 that couples at least one storage device 355 and/or at least one optical drive 360 to the bus. The storage device 355 can include a hard disk drive, not shown, for reading and writing to a disk, a magnetic disk drive, not shown, for reading from or writing to a removable magnetic disk drive. Likewise the optical drive 360 can include an optical disk drive, not shown, for reading from or writing to a removable optical disk such as a CD ROM or other optical media. The aforementioned drives and associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules, and other data for the computer 300 .
[0030] The computer 300 can communicate via a communications channel 365 with other computers or networks of computers. The computer 300 may be associated with such other computers in a local area network (LAN) or a wide area network (WAN), or it can be a client in a client/server arrangement with another computer, etc. Furthermore, the presently preferred embodiment may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. All of these configurations, as well as the appropriate communications hardware and software, are known in the art.
[0031] Software programming code that embodies the presently preferred embodiment is typically stored in the memory 345 of the computer 300 . In the client/server arrangement, such software programming code may be stored with memory associated with a server. The software programming code may also be embodied on any of a variety of non-volatile data storage device, such as a hard-drive, a diskette or a CD-ROM. The code may be distributed on such media, or may be distributed to users from the memory of one computer system over a network of some type to other computer systems for use by users of such other systems. The techniques and methods for embodying software program code on physical media and/or distributing software code via networks are well known and will not be further discussed herein.
System
[0032] FIG. 1 is a flowchart of a system and method for time-sensitive URI mapping. Referring to FIG. 1 , the method and system receive a URI request from a user agent (Step 100 ); initialize the request with a predefined expiration date (Step 105 ); determine a redirection type by comparing the current date with the expiration date (Step 110 ); and present the redirection type to the client computer (Step 115 ) to display the redirected-URI for access by a user (Step 120 ).
[0033] FIG. 2 is a flowchart of the URI mapping and redirection techniques disclosed in the presently preferred embodiment. Referring to FIG. 2 , the user agent, a thin client for example, initiates a request for a page of data identified by a uniform resource identifier (or URI) (Step 200 ) in a distributed multitiered application like that used in the lava Enterprise Edition platform, where a current date is defined by known means. Using techniques commonly understood in the art of programming lava Servlets and J2EE application, the request is initialized (Step 205 ) based on configuration data located in a deployment descriptor, such as a web.xml file, where an expiration identifier is defined (Step 210 ). The expiration identifier can be in a date format, or a special format, such as NOW and NEVER. It is understood that a lava Servlet is a small lava program that runs within a web server, where the servlet receives and responds to requests from web clients across HTTP. Having initiated the necessary redirect behavior, the user agent maps the requested URI using known methods to direct the user agent to the requested resource (Step 215 ).
[0034] The requested URI is instead redirected to a redirect-URI based on time-sensitive information by comparing the current date with the expiration identifier. The special format of NEVER is used to configure that a notification message should always be displayed using the META refresh tag. Also, when a blank or otherwise invalid date is specified, it is equivalent to the special format of NEVER. The special format of NOW is used to configure that a notification message should not be displayed at all, and only a HTTP 301 redirection.
[0035] If the expiration identifier is not in the special format, it is compared with the current date, and if the expiration identifier is less than the current date, then the HTTP 301 redirection is used (Step 225 ) so that the user agent is transparently redirected from the requested URI to the redirect-URI (Step 230 ). The redirected-URI is then displayed (Step 235 ) to the user agent.
[0036] If the expiration identifier is not in the special format, it is compared with the current date and if the expiration identifier is greater than the current date, then the META tag refresh technique is used (Step 240 ). The user agent receives a timed notification that the requested URI has changed (Step 245 ). The user agent is then redirected to the redirect-URI once the timed notification expires (Step 250 ), e.g., 10 seconds, for display to the user agent (Step 235 ).
[0037] For example, if the user agent uses the following to access data:
http://host: 8080/cgi-bin/car/ABC1234DEF567 but the data has been relocated to: http://H/new_host:7001/program/webclient/ABC1234DEF567 and the host:8080 server has the expiration identifier that has already occurred, or the special format of NOW, in its configuration information, the web server performs a 301 redirect and transparently sends the user agent to the second URI.
[0040] Likewise, for example, if the user agent uses the following to access data:
http://host:8080/cgi-bin/car/ABC1234DEF567 but the data has been relocated to: http://H/new_host:7001/program/webclient/ABC1234DEF567 and the host:8080 server has the expiration identifier that has yet to occur, or the special format of NEVER, in its configuration information, the web server performs a META tag refresh and displays the timed notification before refreshing the user agent and redirects the user agent to the redirected-URI.
CONCLUSION
[0043] The presently preferred embodiment may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. An apparatus of the presently preferred embodiment may be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a programmable processor; and method steps of the presently preferred embodiment may be performed by a programmable processor executing a program of instructions to perform functions of the presently preferred embodiment by operating on input data and generating output.
[0044] The presently preferred embodiment may advantageously be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. The application program may be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language may be a compiled or interpreted language.
[0045] Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of nonvolatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing may be supplemented by, or incorporated in, specially-designed ASICs (application-specific integrated circuits).
[0046] A number of embodiments have been described. It will be understood that various modifications may be made without departing from the spirit and scope of the presently preferred embodiment, such as utilizing advance URI mapping logic to determine which URI the user agent should be directed to. Likewise, the system could determine when to switch from META tag refresh to 301 redirect by frequency of page visits as identified from a cookie. Alternatively, the switch from META tag refresh to 301 redirect could occur based on referring URI or originating domain name, for example. Another embodiment within the scope of the claims is the ability to automatically update the favorites or bookmark file for the user agent should the requested URI send the user agent to the redirected-URI. Therefore, other implementations are within the scope of the following claims. | A system, method, and computer program for supporting legacy URIs, comprising the steps of: receiving a request for a uniform resource identifier; initializing said request with at least an expiration identifier, wherein said expiration identifier is one of a date, NOW, and NEVER; determining a redirection type based on a current date, comprising the steps of: if said current date is less than said expiration identifier or equal to NEVER, then use a meta tag redirect; and if said current date is greater than or equal to said expiration identifier or equal to NOW, then use a status code redirect; mapping said URI to a redirect-URI and appropriate means and computer-readable instructions. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a topically applied oral bandage that can be adhered to and is protective of oral mucosa and to a storage stable gel composition providing such bandage.
2. The Prior Art
Aphthous ulcers or oral canker sores are the most common oral lesions afflicting humans. These lesions tend to recur in susceptible patients, often lasting for weeks and are characterized as necrotizing ulcerations of oral mucosal tissue located on soft, non-keratinized mucosa. The lesions are painful, affect nutritional intake, and disrupt oral hygiene. They lead commonly to secondary infections by opportunistic organisms.
Various products are in use for relief of discomfort identified with canker sores and associated lesions such as fever blisters and cold sores, these products forming a protective coating or film about the source of irritation so as to prevent exacerbation of the discomfort caused by normal eating and drinking practices and to allow the lesion to heal naturally. Typically, these products are in the form of ointments and solutions for topical application to the lesions. For the treatment of canker sores, for example, these products have variously employed ingredients such as astringents of which alum and tannic acid are examples, keratolytics such as salicylic acid and anesthetics such as benzocaine.
For example, U.S. Pat. No. 5,081,158 discloses a liquid composition which forms a medicated protective film in situ on oral mucosa, the composition consisting of a medicament dissolved in a solvent such as ethanol, hydroxypropyl cellulose and an agent such as salicylic acid or tannic acid which is disclosed as reacting by esterification with the hydroxypropyl cellulose to form the film. The patent discloses at column 2, lines 27-31, that the formation of the film is specific to hydroxypropyl cellulose and that closely related alkyl or hydroxyalkyl substituted cellulose compounds such as methyl cellulose or hydroxyethyl cellulose are not suitable substitutes for hydroxypropyl cellulose.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method for rapid symptomatic relief of the discomfort associated with lesions of the oral mucosa which method comprises the topical application of a storage stable gel containing an anesthetic compound, an astringent such as tannic acid, a kerolytic compound such as salicylic acid contained in a volatile liquid vehicle such as ethanol and at least 8% by weight of an ethyl cellulose gelling agent, wherein the gel once applied to the oral mucosa, forms upon evaporation of the solvent, an adherent protective film bandage on the afflicted area. The gels of the present invention form an adherent, protective film on the oral mucosa without reliance on chemical reaction as is required with liquid compositions based on hydroxypropyl cellulose.
The oral film bandage formed on lesions in the oral mucosa using the topically applied gel of the present invention exhibits long-lasting adhesion to the oral mucosa, is resistant to removal by saliva flow in the mouth and protects the affected mucosa from worsening of the lesion due to irritation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Ethyl cellulose is known to the art and more fully described in the "Encyclopedia of Polymer Science and Engineering", John Wiley, 2 nd ed. 1985, Vol. 3, p. 254, ff. Ethyl cellulose is soluble in ethanol at a degree of substitution (D. S.) in the range of 2.3 to 2.6.
The amount of ethyl cellulose present in the gel product used in the method of the present invention is from about 8 to about 12% by weight. Concentrations greater than 12% by weight may be used, but such higher concentrations did not materially add to the functionality and stability of the gel product. As will hereinafter be demonstrated, it is critical to the practice of the present invention that the concentration of ethyl cellulose incorporated in the gel formation be at least 8% by weight as such minimum concentration is necessary for satisfactory storage stability of the gel.
Ethyl alcohol is the preferred vehicle for the gel ingredients and preferred amounts range from about 50 to about 60% by weight. Other vehicle materials include purified water in amounts of about 5 to about 10% by and propylene glycol in amounts of about 2 to about 5% by weight.
Benzocaine or benzocaine hydrochloride in amounts of about 10 to about 20% by weight is the preferred anesthetic compound although lidocaine or lidocaine hydrochloride may be substituted for benzocaine or benzocaine hydrochloride. Tannic acid is the preferred astringent compound and is present in the gel formulation at a concentration of about 1 to about 5% by weight. Salicylic acid is the preferred keratolytic agent and is present in the gel formulation at a concentration of about 1 to about 5% by weight.
The gel formulation may also contain pharmaceutically inactive ingredients as for example, a sweetener such as sodium saccharin (0.1-1% by weight) and a flavorant (0.1-1% by weight) such as mint and menthol flavors.
The gel compositions of the present invention are easy to package in conventional containers and as will hereinafter be demonstrated have good stability upon long term storage at ambient and elevated temperatures. Containers known to the pharmaceutical and cosmetic arts as being suitable for the storage and convenient dispensing of gels for topical use may be used to package the gel of the present invention, tubes being preferred as the gel of the present invention is in extrudable form. In tubes, the gel composition of the present invention may be easily transported in an individual's pocket, purse or carrying bag and small quantities may be effectively dispensed for use with little waste and discomfort due to spillage. The gel composition of the present invention is also of pleasant appearance, odor and consistency, all of which promotes and enhances the patient's desire to use the gel composition as needed to relieve pain and discomfort of lesions in the oral mucosa.
The gels of the present invention may be prepared by any conventional process known in the pharmaceutical and cosmetic arts. In accordance with a preferred procedure, a sweetener is dissolved in water to prepare a first phase. A second phase is prepared by mixing antiseptic, flavorant, kerolytic and astringent compounds with alcohol. The first and second phases are then mixed together until a homogenous gel is obtained, all process steps being performed at ambient room temperature (20°-25° C.).
The following example provides a detailed illustration of a gel composition according to the present invention as well as a method of producing the same.
EXAMPLE
A gel formulation adapted for topical application to the oral mucosa to form an oral bandage film to protect lesions formed from further irritation was prepared having the following ingredients:
______________________________________Ingredients Weight %______________________________________Purified water 6.0Saccharin sodium 0.3Ethyl alcohol (95%) 57.2Benzocaine 15.0Propylene glycol 3.0Tannic acid, USP 7.0Salicylic acid USP 3.0Mint flavor 0.5Ethyl cellulose 8.0______________________________________
The following procedure was used to prepare the gel formulation:
Fifteen (15) kilograms (kg) of purified water was transferred at 23° C. into a 10 gallon capacity stainless steel kettle equipped with a high speed mixing device. Sodium saccharin USP (0.9 kg) was added to the water and agitation was continued for 15 minutes to assure that the saccharin was dissolved in the water.
Ethyl alcohol 95%, USP (171.6 kg) was transferred into a steam jacketed tank and the temperature maintained at 20°-25° C. Benzocaine (45.0 kg) was added to the ethyl alcohol and then agitated for 10 minutes to insure that the benzocaine was dissolved in the ethyl alcohol. The following ingredients were added to the ethanol solution in the order given and agitation continued for a sufficient time (5-10 minutes) to insure that each ingredient was completely dissolved before adding the next.
Propylene Glycol USP (9.0 kg)
Tannic Acid, USP (21.0 kg)
Salicylic Acid (9.0 kg)
Cool Frost Flavor (1.5 kg)
Ethyl cellulose (24.0 kg)
After complete dissolution of the ingredients added to the steam jacketed tank was achieved, the aqueous saccharin solution from the stainless steel kettle was then added to the ingredients in the steam jacketed tank and the ingredients agitated until complete dissolution was obtained. The resultant composition was a clear amber colored gel having an antiseptic medicinal color and an antiseptic mint taste, a pH of 3.4-3.9 and a specific gravity of 0.8812-0.9740.
For purpose of comparison when the procedure of the Example was repeated except hydroxypropyl methyl cellulose (5.0%) was substituted for ethyl cellulose, the hydroxypropyl methyl cellulose product did not form a homogeneous gel.
The gel composition of the Example was tested for storage stability using an accelerated aging test wherein plastic tubes filled with the gel were maintained at 105° F. for 4 weeks. The results are recorded in the Table below.
For purposes of further comparison, the procedure of the Example was repeated, except that lower concentrations of ethyl cellulose, i.e., 2.5% and 5.0% by weight were used to prepare the gel. The results of these comparative aging tests are also recorded in the Table below.
______________________________________Ethyl Cellulose Aging Period AppearanceConcentration in Gel (Wt. %) Weeks @ 105° F.) of Aged Gel______________________________________5.0 4 Very thin gel8.0 4 Thick gel______________________________________
It was determined that the gel composition of the Example when topically applied with a cotton swab to the inner lip of human subjects promptly formed a coherent film that was strongly adherent to the mucosa and had an opaque, continuous and occlusive appearance.
To determine the acceptability of the gel of the Example to consumers, sixty-four dentists and oral hygienists at a professional dental meeting were asked to compare the physical properties of the gel product prepared in accordance with the procedure disclosed in the Example against a comparative gel which had been prepared in accordance with the procedure of the Example, except 2.5% hydroxypropyl cellulose was used to prepare the gel instead of ethyl cellulose. The gel prepared in accordance with the Example was preferred by a predominate number of the test participants, that is, 47 of the 64 dental professionals who participated in the evaluation preferred the ethyl cellulose formulated gel product over the hydroxypropyl cellulose formulated gel. | A method of administering an oral bandage to lesions in the oral mucosa is disclosed wherein there is prepared a storage stable topical gel formulation adapted to form an oral bandage adherent to the oral mucosa when applied thereto, the gel containing at least one anesthetic compound, a keratolytic compound, an astringent compound and an ethyl cellulose gelling agent in an amount of at least about 8% by weight and then applying the gel to the area of the oral mucosa experiencing irritation to form an adherent oral bandage. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control system for an automotive air conditioning unit. More particularly, the present invention relates to a control system which acts to disengage an air conditioner from the power train of a vehicle when engine power is needed for other uses such as, accelerating, travelling uphill, and towing heavy payloads.
2. Description of the Prior Art
In all motorized vehicles with air conditioning systems, the power available, for example for acceleration and traveling uphill, is reduced when the air conditioning system is turned on. With the increase in consumer demand for cars with greater fuel economy, there has been a great rise in the popularity of cars with smaller engines, in particular cars with small four cylinder engines. Such small engines have more limited power outputs than, for example, the large eight cylinder engines popular in the recent past.
Because of the limited power of such small engines, it is often impossible, in cars with such engines, to accelerate quickly or to travel uphill at a reasonable speed, with the air conditioner on. Also, in the case of police vehicles for example, when the quickest possible acceleration is required, it is desirable to direct all available power to the drive wheels without the need for the vehicle operator's intervention. For these reasons, many systems have been proposed in the prior art for automatically turning off a vehicle's air conditioner when the demand for engine power is high.
U.S. Pat. No. 5,271,368, issued to Fujii et al., shows a fuel supply control system which cuts off fuel supply to the engine during deceleration when the engine speed is higher than a first preset value with the air conditioner on, and when the engine speed is higher than a second preset value with the air conditioner off, the first preset value being greater than the second preset value.
U.S. Pat. No. 5,261,368, issued to Umemoto, shows an engine control system for preventing engine stall when the engine returns from operating under a load to an idling condition. The Umemoto system supplies auxiliary air to the engine, to prevent the engine speed from dropping below the idle setting in the period of time immediately following the return of the throttle valve to the idling position.
U.S. Pat. No. 5,133,302, issued to Yamada et al., shows a control system, for controlling the cooling fan of an engine, which uses the vehicle speed, coolant temperature, and refrigerant pressure at the compressor discharge outlet, to determine whether the cooling fan should be on or off.
U.S. Pat. No. 5,050,395, issued to Berger, shows a an air conditioning shutoff system that uses the difference between fuel consumption per stroke at idle and actual fuel consumption per stroke, as the criterion for shutting off the vehicle's air conditioner. In addition, the Berger system uses engine RPM, vehicle speed, and accelerator pedal position, as further parameters for determining when to shutoff the air conditioner. All the aforementioned additional parameters have preset thresholds, and the air conditioner is not shutoff if the value for any one of these parameters is above its preset threshold.
U.S. Pat. No. 5,027,609, issued to Yashiki et al., shows an air conditioning shutoff system where the air conditioner is shutoff when the intake pressure is above a certain threshold. In the Yashiki et al. system, the intake pressure threshold is dynamically varied depending on engine RPM and ambient pressure.
U.S. Pat. No. 4,823,555, issued to Ohkumo, shows an air conditioner shutoff system which compares the actual engine intake pressure to a reference pressure which is a function of the vehicle's speed, and shuts off the air conditioner if the intake pressure is higher than the reference pressure at a particular vehicle speed.
U.S. Pat. No. 4,688,530, issued to Nishikawa et al., shows an air conditioning shutoff system which operates to shutoff the air conditioner compressor when the vehicle is in a low speed range and the throttle opening is less than a reference amount. The purpose of this control system is to eliminate engine vibrations when the vehicle's automatic transmission down-shifts at low speed, with the air conditioner running.
U.S. Pat. No. 4,658,943, issued to Nishikawa et al., shows an air conditioner shutoff system which uses the data from the electronic controller of the vehicle's automatic transmission to determine whether the throttle opening and the vehicle speed are within a "prohibition region" within the shift map stored in the transmission controller. If the values for the vehicle speed and throttle opening are within the "prohibition region" and certain other requirements, regarding the selected gear and the elapsed time kept by a timer are met, then the air conditioner is shutoff. Also the air conditioner is shutoff if the engine speed in rpm is below a reference value.
U.S. Pat. No. 4,615,180, issued to Rudman, shows an inertial mercury switch which tilts in response to vehicle acceleration, and causes an open circuit when tilted. By incorporating this switch in the circuit supplying power to the air conditioner compressor clutch, the air conditioner compressor can be cut out during vehicle acceleration, thereby making more engine power available for acceleration. The Rudman system fails to cut out the air conditioner when towing a heavy load at constant speed, a condition which also requires greater engine power output.
U.S. Pat. No. 4,610,146, issued to Tanemura, shows a an air conditioning shutoff system that uses fuel temperature to determine when the engine is running under a heavy load. In addition, the Tanemura system incorporates a detector for detecting the amount of accelerator pedal depression, and a speed sensor. When the fuel temperature is higher than a certain level, the accelerator pedal is depressed further than a preset amount, and the vehicle speed is below a preset level, the system of Tanemura acts to shutoff the air conditioner compressor.
U.S. Pat. No. 4,510,764, issued to Suzuki, discloses an air conditioning cut-off where during acceleration or high load operation the power supplied to the air conditioner is reduced or eliminated. Suzuki uses the intake pressure of the engine to detect high load operation. Suzuki does not disclose how his system determines whether or not the vehicle is accelerating.
U.S. Pat. No. 4,488,410, issued to Seiderman, shows an air conditioner cut-off system which uses an on-off switch, actuated by the gear shift lever, to turn off the air conditioner while the transmission is being shifted between neutral and high gear. Presumably, as the transmission is being shifted through the low gears, demand for engine power is high and the air conditioner should be turned off.
U.S. Pat. No. 4,445,341, issued to Hayashi, shows an air conditioner cut-off which uses the engine air intake vacuum to determine whether or not the vehicle is under acceleration and, in response to a determination that the vehicle is accelerating, turns off the air conditioner.
U.S. Pat. No. 4,369,634, issued to Ratto, shows another example of an air conditioner cut-off which uses the engine air intake vacuum to determine whether or not there is a demand for high engine power, and turns off the air conditioner when there is a demand for high engine power.
U.S. Pat. No. 4,359,875, issued to Ohtani, shows an air conditioning cut-off which uses engine intake vacuum to determine when the vehicle is in a condition other than standing still or travelling at constant velocity. The air conditioner is then turned off when the intake manifold pressure is greater than -150 mmHg.
U.S. Pat. No. 4,305,360, issued to Meyer et al., shows a control system for automatically setting the idle speed of the engine. The Meyer et al. system automatically opens the throttle valve, when the engine speed drops below the idle speed setting, to a position which brings the engine speed up to the idle speed setting.
U.S. Pat. No. 4,299,094, issued to Lummen, shows an air conditioner cut-off system which uses a mercury switch to turn the air conditioner on and off. Again the mercury switch is responsive to engine intake vacuum.
U.S. Pat. No. 4,269,033, issued to Birch, shows a pressure sensitive switch for turning off the air conditioner in response to high intake manifold pressure. The pressure sensitive switch of Birch has an adjustment screw which allows the degree of vacuum, which causes the air conditioner to be turned off, to be set by the vehicle operator.
U.S. Pat. No. 4,237,838, issued to Kinugawa et al., shows an engine control system that regulates the amount of air flowing into the engines intake manifold.
U.S. Pat. No. 4,135,368, issued to Mohr et al., shows an air conditioner cut-off which turns off the air conditioner in response to high engine intake pressure, and turns on the air conditioner after a pre-programmed time of three to seven seconds.
U.S. Pat. No. 3,462,964, issued to Haroldson, shows a pressure sensitive switch for turning off the air conditioner in response to high intake manifold pressure.
Japanese Patent Document Number 55-151135 shows a control system for controlling the supply of auxiliary air to the intake manifold of an engine.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention is directed to an automotive air conditioner shutoff system that disengages the air conditioner compressor when the value of a parameter indicative of the vehicle's performance is below a certain variable threshold. The threshold varies as a continuous function of accelerator pedal position or throttle valve position. In addition, the air conditioner fan may also be controlled by the air conditioner shutoff system of the present invention. Further, the air conditioner shutoff system of the present invention may act to shut off the air conditioner when the engine is over heated or when the engine has not yet warmed up. Additionally, provision is made for allowing the vehicle operator to modify the value of the variable threshold for the vehicle performance indicating parameter, and for allowing the vehicle operator to entirely override the air conditioning shutoff system.
Accordingly, it is a principal object of the invention to provide an air conditioner shutoff system which makes maximum engine power available, for acceleration and hill climbing for example, when the air conditioner is running, without the need for operator intervention.
It is another object of the invention to provide an air conditioner shutoff system which improves vehicle gas mileage by temporarily disengaging the air conditioner compressor from the power train, when the engine is operating under a high demand for power output.
It is a further object of the invention to provide an air conditioner shutoff system which disengages the air conditioner compressor in the period immediately following engine start-up, thus reducing the burden on the engine while it is warming up and increasing engine life.
Still another object of the invention is to provide an air conditioner shutoff system which greatly reduces the possibility of engine overheating when demand for engine power is high and the air conditioner is running.
Still another object of the invention is to provide an air conditioner shutoff system which can be readily retrofitted in existing vehicles.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the automatic air conditioner shutoff system of the present invention.
FIG. 2 is a flow chart showing the control algorithm used in the automatic air conditioner shutoff system of the present invention.
FIG. 3 is a fragmentary perspective view showing the torque sensor most preferably used with the automatic air conditioner shutoff system of the present invention.
FIG. 4 is a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, manual transmission vehicle during acceleration on level ground.
FIG. 5 is a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, manual transmission vehicle during travel on shallow and steep hills.
FIG. 6 is a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, automatic transmission vehicle during acceleration on level ground.
FIG. 7 is a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, automatic transmission vehicle during travel on shallow and steep hills.
FIG. 8 is a graph showing the temporal relationship between the detection of the engine being in a running condition and the on/off state of the air conditioner.
FIG. 9 is a graph showing the temporal relationship between the engine or coolant temperature and the on/off state of the air conditioner.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a schematic diagram of an internal combustion engine vehicle equipped with an air conditioner and incorporating the automatic air conditioner shutoff system of the present invention can be seen. Generally, the overwhelming portion of the energy consumed by an air conditioning system is consumed by compressor 10 which acts to compress the refrigerant after the refrigerant has passed through an expansion valve. A less significant amount of energy is consumed by the air conditioner fan 12 which circulates air passed the cooling coils of the air conditioner. To achieve the goals of the present invention, it is sufficient for the automatic air conditioner shutoff system of the present invention to disengage the compressor only. However, if desired, the automatic air conditioner shutoff system of the present invention can also be used to shut off the air conditioner fan.
The details of the air conditioning system itself are well known, and therefore are not shown in the drawings.
The compressor is generally driven via an electromagnetic clutch 14 interposed between a pulley 16 and the compressor 10. A belt 18 engages the pulley 16, and drives the pulley 16 using power from the engine 20. When the electromagnetic clutch 14 is energized, the compressor is engaged to the pulley and is driven by the engine. A relay switch 22 acts to selectively deliver or interrupt electrical power supply to the electromagnetic clutch 14. A similar relay switch 24 controls the delivery of electrical power to the electric motor 26 driving the air conditioner fan 12. The relay switch 24 controlling the fan is preferably in parallel with the relay switch 22 controlling the power to the electromagnetic clutch. Both relay switches are controlled by the same control signal line 28 from the automatic air conditioner shutoff system 29, referred to herein by the acronym AACSS.
The AACSS receives input signals from a performance-indicating parameter sensor 30, an engine coolant temperature sensor 32, a timer circuit 34, a manual override switch 36, throttle or accelerator pedal position sensor 38, and a threshold setting switch 40. The AACSS outputs a reset signal 42 to the timer circuit in order to reset the timer 34 as necessitated by the control algorithm which will be discussed below. The AACSS itself includes a microcomputer, input/output circuitry, and analog to digital converter circuitry for converting transducer inputs to digital signals. The microcomputer includes memory circuits, a central processing unit (CPU), registers for temporary data storage within the CPU, comparator circuitry, and arithmetic circuitry. The memory circuits include both read only memory (ROM) and random access memory (RAM). The aforementioned component circuits of the AACSS are all well known in the art and therefore are not shown in the drawings or discussed in detail herein.
Most preferably, the AACSS is installed so as to be automatically engaged when the vehicle is started. In addition, preferably the AACSS draws power from the vehicle battery so that it can perform the necessary shut-down routines when the engine is turned off.
Referring to FIG. 2, the algorithm followed by the AACSS can be seen. When the engine is first started, the CPU is initialized to ensure that the relay switches are in the open position, i.e. the compressor and the fan are shut off, when the running of the algorithm is initiated. During this initial state the signal on signal line 28 is said to be off or in the off state. Also, immediately following the starting of the engine, the timer circuit 34 is reset, i.e. set to zero. This initialization phase further includes a step of setting a bit within the CPU. This bit is allocated for the purpose of implementing a delay before allowing the compressor and fan to turn on, following a determination that there is no longer a high demand for engine output. This bit is referred to as the "delay air conditioner on" flag or DACO flag.
In step 48, it is determined if the engine is running or not. If the engine is running, program execution is continued. Otherwise the program is terminated. Whether or not the engine is running can for example easily be determined by monitoring the alternator output using conventional current measuring means. The subsystem for determining whether or not the engine is running is designated as the engine-on sensor 44.
Thereafter, in step 50 the elapsed time t is compared to the preselected stabilization time interval t w . If t is less than t w , the air conditioner is maintained in the inoperative state. The time interval t w can range from 3 to 10 seconds, and can either be entered into ROM at the time of system installation or can be entered by the vehicle operator using a conventional input device such as a keypad (shown as optional driver interface device 46, in FIG. 1). The reason for the delay t w , is to increase engine life by preventing the engagement of the compressor and the turning on of the fan, before the engine has had a chance to reach stable running condition. By stable running condition, it is meant that parameters, such as engine temperature and oil pressure, have reached normal operating levels.
Steps 48 and 50 are repeated until t becomes greater than or equal to t w , at which time program execution continues to step 52. In step 52 the coolant temperature T is compared to the reference value T r . If T is greater than or equal to T r an engine overheat condition exists and the air conditioner compressor and fan should be kept off. This step helps prevent further overheating of the engine and allows the engine to return to normal operating temperature more quickly. The reference value T r represents the upper limit of the normal operating temperature range of the engine and varies depending on the particular engine design. The value of T r can be readily obtained by reference to the manufacturers specifications for the particular engine.
If the engine is overheated the air conditioner is turned off and the program is terminated. As an alternative, step 52 is repeated as long as T remains above T r . In either case, if the engine is not overheated, program execution continues to step 54.
In step 54, whether or not the engine is running is again ascertained. If the engine is running, program execution is continued to step 55. Otherwise the program is terminated as before.
In step 55 the value of the power demand indicating parameter θ, i.e. the throttle position or the accelerator pedal position, is acquired. At step 56 the threshold value γ T (θ) for the performance-indicating parameter γ is calculated. The threshold value for the performance indicating parameter is given by reducing the ideal value of the parameter γ i (θ) by a certain percentage. The ideal value of the performance indicating parameter is the steady state value, on level ground, for the parameter at the previously acquired value of throttle or accelerator pedal position θ. The ideal values of the performance indicating parameter are stored in memory, for discrete points distributed over the entire range of throttle or accelerator pedal positions. The greater the number data points stored in memory, the more accurately the AACSS can control the air conditioner. With the low cost high density memory circuits and flash RAM cards currently available, it should be an inexpensive proposition to store at least on the order of several thousand data points. Alternatively regression equations correlating the ideal value data may be programmed into the microcomputer and used to calculate the ideal values over a continuum of power demand indicating values. To calculate γ T (θ), γ i (θ) is "looked up" in memory for the stored θ closest to the acquired value of θ. Alternatively, some sort of interpolation scheme may be used to find γ i (θ), or γ i (θ) may be calculated using the previously mentioned regression equations. The value for γ i (θ) is then multiplied by the quantity (100-δ)/100, where δ is the percentage reduction in γ i (θ), in order to obtain the value for γ T (θ).
The percentage reduction δ is entered by the vehicle operator using the threshold setting switch 40. The threshold setting switch 40 can for example be of the sliding type which allows δ to be continuously varied over a range of 1% to 100%. The actual value of δ would depend on the vehicle operator's driving style. If the operator values performance more than cabin interior comfort, he or she would pick a relatively small value for δ. In this case even small reductions in the value of the performance indicating parameter, as compared to its ideal value, would cause the air conditioner to be shut off. If on the other hand, the operator would rather compromise performance in the interest of cabin interior comfort, then a relatively higher value for δ would be selected. In this case a greater reduction in the value of the performance indicating parameter, as compared to its ideal value, would be required to cause the air conditioner to be shut off.
After γ T (θ) is calculated, the real time value of the performance-indicating parameter θ is compared to γ T (θ) in step 58. If the real time γ is less than γ T (θ), then the air conditioner is maintained in the inoperative state, the DACO flag is cleared, and control of program execution is returned to step 52. If the real time γ is greater than or equal to γ T (θ), program execution continues to step 60.
In step 60, the value of the DACO flag is tested. If the DACO flag is clear; then the DACO flag is set, the timer circuit is reset, and t is compared to t o , where t o is the delay before turning the air conditioner on. If t is less than t o then the test loop is run again while the air conditioning remains off during the t o time interval. If the DACO flag is set, i.e. is equal to logical one, then the steps of setting the DACO flag and resetting the timer circuit are skipped, and t is again compared to t o . This process is repeated until t becomes equal to or greater than t o , at which time the signal on signal line 28 goes on.
The delay t o ranges from 1-3 seconds, and is intended to prevent the turning on of the air conditioner due to highly transitory increases in the performance indicating parameter to above-threshold values, as happens when shifting gears for example, thus saving wear and tear on the electromagnetic clutch, compressor, and fan.
When the signal on signal line 28 goes on, current is allowed to flow through the transistor 62, thus closing relay switches 22,24 and causing the compressor to be engaged and the fan to be turned on, effectively turning on the air conditioner. As an alternative, a silicon controlled rectifier may be used in place of transistor 62. Control of program execution is then returned to step 52.
The parameter γ is selected, depending on the particular embodiment, from the group consisting of vehicle speed, engine speed (i.e. engine rpm), and torque measured at the drive axle. Depending upon the choice for the performance-indicating parameter γ, the sensor 30 will be a vehicle speed sensor, an engine speed sensor, or an axle torque sensor. All these various sensors are well known in the art and will not be shown or discussed in detail here.
U.S. Pat. No. 5,304,102, issued to Narita et al. and incorporated herein by reference, shows an engine speed sensor and output shaft torque sensor of the types useful in the present invention. U.S. Pat. No. 5,259,241, issued to Wakayama and incorporated herein by reference, shows a vehicle speed sensor of the type useful in the present invention. U.S. Pat. No. 5,262,717, issued to Bolegoh and incorporated herein by reference, shows a shaft torque sensor of the type most preferably used in the present invention.
Referring to FIG. 3, the torque sensor 64 most preferably used with the present invention can be seen. This torque sensor is of the same type as disclosed in U.S. Pat. No. 5,262,717, which was previously incorporated by reference. The torque sensor includes a strain gauge 66 which is cemented to, or in some other manner affixed to, the propeller shaft or drive axle 68 of a vehicle. The torsional strain in the shaft 68, which is proportional to the torque exerted through the shaft, causes a strain in the strain gauge. The strained state of the strain gauge generates an electrical signal which is conducted to a rotary antenna 70 via conductor 72. The rotary antenna is so called because it is fixed to the shaft and rotates with it. A stationary antenna 74 encircles the shaft 68, and picks up the strain gauge signal. The strain gauge signal is then conducted via a power supply 76 and cable 78 to the AACSS for use in the control program. For details of the construction and calibration of the torque sensor 64 reference is made to U.S. Pat. No. 5,262,717.
The AACSS can be designed to incorporate, as much as possible, a vehicles existing equipment, such as sensors and on-board computers, thus allowing it to be readily retrofitted to existing vehicles having electronically controlled automatic transmissions or computerized engine control systems. All of the subsystems and circuits shown in the figures in block form are well known in the art and can be readily obtained.
FIG. 4, shows a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, manual transmission vehicle during acceleration on level ground. Only three gear changes are shown for clarity. Curve A shows the engine speed in rpm, which is the performance indicating parameter in this example. Curve B shows the accelerator pedal position, which is the power demand indicating parameter in this example. Curve C is a logical depiction of whether the realtime value of the engine speed is above or below threshold, logical "high" indicating an above threshold value and a logical "low" indicating a below-threshold value. Curve D shows the state of the air conditioner, "high" meaning the air conditioner is on and "low" meaning the air conditioner is off. The horizontal dotted lines show the calculated thresholds for the engine speed at the particular accelerator pedal positions.
At first the vehicle is travelling in first gear at the ideal engine speed for the given pedal position. At this time the engine speed is above the threshold value and the air conditioner is on. As acceleration begins the accelerator pedal is deeply depressed. As shown in curve B, the threshold value at this new accelerator pedal position is far higher than before and the realtime engine speed is now well below the threshold indicating a high demand for power. At this time curve C goes low indicating that the condition for shutting off the air conditioner is now met, and curve D goes low indicating that the air conditioner is now off.
As the vehicle accelerates further the need for gear changes arise. During these gear changes the operator's foot is lifted from the accelerator pedal, and the engine speed momentarily is above the calculated threshold value. This phenomenon is manifested by the curve C going high briefly with each gear shift. However, since the duration of each episode of curve C being high, is less than t o , 3 seconds in this example, the air conditioner remains off. Once the desired speed is reached in third gear, the operator eases off the accelerator pedal, however the accelerator pedal remains more deeply depressed than it was initially. Once again the engine speed is above the threshold speed, since now the engine speed is at the ideal level. This time the duration of the condition for turning the air conditioner on is greater than 3 seconds, and therefore the air conditioner is turned on as seen in curve D.
FIG. 5, shows a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, manual transmission vehicle during travel on shallow and steep hills. Curve A shows the engine speed in rpm, which is the performance indicating parameter in this example. Curve B shows the accelerator pedal position, which is the power demand indicating parameter in this example. Curve C is a logical depiction of whether the realtime value of the engine speed is above or below threshold, logical "high" indicating an above threshold value and a logical "low" indicating a below-threshold value. Curve D shows the state of the air conditioner, "high" meaning the air conditioner is on and "low" meaning the air conditioner is off. The horizontal dotted lines show the calculated thresholds for the engine speed at the particular accelerator pedal positions.
At first the vehicle is travelling on a level road at the ideal engine speed. At this time the engine speed is above the threshold value and the air conditioner is on. At steady state on a shallow hill the accelerator pedal is more deeply depressed, however, because of the effect of δ discussed above, the engine speed is still above the threshold even though it is less than the ideal speed. The air conditioner remains on.
When climbing a steep hill, the accelerator pedal is even more deeply depressed, and eventually the engine speed falls below the calculated threshold value. The realtime engine speed is now well below the threshold indicating a high demand for power. At this time curve C goes low indicating that the condition for shutting off the air conditioner is now met, and curve D goes low indicating that the air conditioner is now off.
As the vehicle comes to level ground, the operator eases off the accelerator pedal. Once again the engine speed is above the threshold speed, since now the engine speed is at the ideal level. Once the vehicle has travelled on level ground for more than 3 seconds, the duration of the condition for turning the air conditioner on is greater than 3 seconds, and therefore the air conditioner is turned on as seen in curve D.
FIG. 6, shows a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, automatic transmission vehicle during acceleration on level ground. Curve A shows the vehicle speed in mph, which is the performance indicating parameter in this example. Curve B shows the accelerator pedal position, which is the power demand indicating parameter in this example. Curve C is a logical depiction of whether the realtime value of the vehicle speed is above or below threshold, logical "high" indicating an above threshold value and a logical "low" indicating a below-threshold value. Curve D shows the state of the air conditioner, "high" meaning the air conditioner is on and "low" meaning the air conditioner is off. The horizontal dotted lines show the calculated thresholds for vehicle speed at the particular accelerator pedal positions.
At first the vehicle is travelling at the ideal speed for the given pedal position. At this time the vehicle speed is above the threshold value and the air conditioner is on. As acceleration begins the accelerator pedal is deeply depressed. As shown in curve B, the threshold value at this new accelerator pedal position is far higher than before and the realtime vehicle speed is now well below the threshold indicating a high demand for power. At this time curve C goes low indicating that the condition for shutting off the air conditioner is now met, and curve D goes low indicating that the air conditioner is now off.
Once the desired speed is reached, the operator eases off the accelerator pedal, however the accelerator pedal remains more deeply depressed than it was initially. Once again the vehicle speed is above the threshold speed, since now the vehicle speed is at the ideal level. Once the duration of the condition for turning the air conditioner on is greater than t o , 1 second in this example, the air conditioner is turned on as seen in curve D.
FIG. 7, shows a graph demonstrating the temporal relationship between the performance indicating parameter, the power demand indicating parameter, and the state of the vehicle's air conditioner, for an AACSS equipped, automatic transmission vehicle during travel on shallow and steep hills. Curve A shows the vehicle speed in mph, which is the performance indicating parameter in this example. Curve B shows the accelerator pedal position, which is the power demand indicating parameter in this example. Curve C is a logical depiction of whether the realtime value of the vehicle speed is above or below threshold, logical "high" indicating an above threshold value and a logical "low" indicating a below-threshold value. Curve D shows the state of the air conditioner, "high" meaning the air conditioner is on and "low" meaning the air conditioner is off. The horizontal dotted lines show the calculated thresholds for the vehicle speed at the particular accelerator pedal positions.
At first the vehicle is travelling on a level road at the ideal vehicle speed. At this time the vehicle speed is above the threshold value and the air conditioner is on. At steady state on a shallow hill the accelerator pedal is more deeply depressed, however, because of the effect of δ discussed above, the vehicle speed is still above the threshold even though it is less than the ideal speed. The air conditioner remains on.
When climbing a steep hill, the accelerator pedal is even more deeply depressed, and eventually the vehicle speed falls below the calculated threshold value. The realtime vehicle speed is now well below the threshold indicating a high demand for power. At this time curve C goes low indicating that the condition for shutting off the air conditioner is now met, and curve D goes low indicating that the air conditioner is now off.
As the vehicle comes to level ground, the operator eases off the accelerator pedal. Once again the vehicle speed is above the threshold speed, since now the vehicle speed is at the ideal level. Once the vehicle has travelled on level ground for more than 1 second, the duration of the condition for turning the air conditioner on is greater than 1 second, and therefore the air conditioner is turned on as seen in curve D.
FIG. 8, shows the temporal relationship between the detection of the engine being in a running condition (curve A) and the on/off state of the air conditioner (curve B). When curve B is "high" the air conditioner is on, and when curve B is "low" the air conditioner is off. The main feature of FIG. 8 is that there is, as an example only, a 5 second delay between the time the engine is turned on and the time the air conditioner is turned on. This Figure demonstrates the effect of the delay for allowing the engine to obtain stable running condition.
FIG. 9, shows the temporal relationship between the engine or coolant temperature (curve A) and the on/off state of the air conditioner (curve B). When curve B is "high" the air conditioner is on, and when curve B is "low" the air conditioner is off. The main feature of FIG. 9 is that the air conditioner is turned off once the engine or coolant temperature exceeds the preselected threshold.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. | An automotive air conditioner shutoff system that disengages the air conditioner compressor when the value of a parameter indicative of the vehicle's performance is below a certain variable threshold. The threshold varies as a continuous function of accelerator pedal position or throttle valve position. In addition, the air conditioner fan may also be controlled by the air conditioner shutoff system of the present invention. Further, the air conditioner shutoff system of the present invention may act to shut off the air conditioner when the engine is overheated or when the engine has not yet warmed up or stabilized. Additionally, the vehicle operator can modify the value of the variable threshold for the performance indicating parameter, and entirely override the air conditioning shutoff system. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to assays for the determination of analytes in fluids.
Many types of assay elements for the rapid analysis of analytes present in biological fluids are known in the art. Of particular interest are dry multilayer analytical elements to which the sample, e.g., a drop of blood, serum or plasma, is applied and allowed to migrate or diffuse to a reagent layer or layers. As a result of the interaction between the analyte and the reagent(s) present, a detectable change is brought about in the element corresponding to the presence of the analyte in the sample. The detectable change can be a color change which may be evaluated visually or read spectrophotometrically such as with a densitometer. In another scheme based on the presence of fluorescent-labeled biologically active species, a fluorescent output signal can be generated and read spectrofluorometrically. Such assay elements are of great interest because they can be adapted for use in automated analytical instruments.
In the automated analytical instruments a sample of a test fluid is typically provided in a sample cup and all of the assay method steps including pipetting of a measured volume of the sample onto an assay element, incubation and readout of the signal obtained as a result of the interactions(s) between the reagent(s) and the sample analyte are carried out automatically. The assay element is typically transported from one station, e.g. the pipetting station, to another, e.g. the optical read station, by a transport means such as a rotating carousel to enable the test steps to be carried out automatically.
Such automated analytical instruments are capable of processing many assay elements rapidly and it is necessary to achieve a very high level of precision for these assays. However, imprecisions in the results obtained can be caused by a number of factors. For example, any element to element variation in the distance from the optical readout apparatus to the signal-generating species when readout of the signal is carried out will introduce imprecision into the results as will any element to element variation in the thickness of the layer in which the signal-generating species resides when it is read.
The reagent layer(s) in thin film multilayer assay elements may be extremely thin, that is, on the order of about 0.01 mm or less. Accordingly, although such layers can be coated with a very high degree of precision nevertheless some slight variation in the thickness of the reagent layers will exist on an element to element basis. Similarly, although the transport means e.g. a carousel, for the assay elements can be engineered within very exact tolerances, nevertheless there will exist some slight variations in the instrument position response for the respective assay element positions on the transport means.
It is desirable therefore to have a method for compensating for signal imprecisions caused by variations in reagent levels from element to element and variations in instrument position response as well those caused by other factors.
BRIEF SUMMARY OF THE INVENTION
These and other objects and advantages are accomplished in accordance with the invention by providing a method for determining the amount of an analyte in a sample fluid such as whole blood, plasma, serum, etc. The assay method is carried out with an assay element which includes at least one reagent layer and a light-blocking layer. The light-blocking layer provides an optical bound/free separation of a signal-generating species as a function of the amount of analyte in the sample fluid. The signal-generating species in the assay element is read optically a first time prior to delivering the sample fluid to the element. Subsequently, after the sample fluid has been applied to the assay element and the interaction between the sample analyte and the reagent(s) present in the element has taken place, the signal producing species is read optically a second time. This second optical reading is carried out by irradiating the same layer of the assay element as that read in the first optical reading and doing so at the same wavelength. The ratio of the second signal to the first signal is taken and compared with that for known amounts of the analyte to determine the amount of the analyte in the sample fluid.
By normalizing the signal obtained from the assay in this manner it is possible to compensate for variations in reagent levels because of variations in reagent layer thicknesses from element to element and also for variations in the analytical instrument position response. The compensation for such variations provides significantly improved precision in the assay method.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention as well as other objects and further features thereof, reference is made to the following detailed description of various preferred embodiments thereof taken in conjunction with the accompanying drawings wherein: the Figure is a partially schematic cross-sectional view of an assay element which can be utilized in the method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The assay elements which are utilized in the assay method of the invention may include any suitable signal-generating species. Any light radiation emitting or absorbing label, including a label which reacts with a reagent, which provides a detectable signal can be utilized as the signal-generating species. The label may be a fluorophore, a phosphor or a light absorbing material.
The assay method of the invention will be described in detail with respect to a preferred embodiment of an assay element which may be utilized therein. Referring now to the Figure there is seen an assay element 10 which is a thin film multilayer element typically having a thickness of about 0.1 mm and comprised of a transparent support 12 which carries in succession a reagent layer 14, a light-blocking layer 16 and an optional top coat layer 18 which may serve as a reagent layer, a filter layer such as for proteins, an anti-abrasion layer, etc. The reagent layer 14 is very thin, typically having a thickness of about 0.025 mm and includes an immunocomplex of a binding partner for the analyte of interest and a conjugate of a labeled analyte (the same as the sample analyte, an analogue thereof or a structurally similar material which will bind to the binding partner). The binding partner, an antibody when the sample analyte is an antigen, is immobilized in the reagent layer 14 by being covalently bound to the surface of the support layer 12, which may be of any appropriate material such as a polyester or a polystyrene, or to a matrix material or by being physically held by the matrix material. The matrix material may be a hydrophilic gel material such as gelatin, a polysaccharide, e.g. agarose, a derivatized polysaccharide, mixtures thereof, and the like. Light-blocking layer 16 may comprise any suitable material such as, for example, iron oxide, titanium dioxide or the like dispersed in a binder material such as a polysaccharide. The optional topcoat layer 18 may comprise an anti-abrasion layer of a material such as a polysaccharide or preferably may include buffers, blocking and displacing agents, etc.
The assay element 10 may also include a layer or other means (not shown) for distributing the sample fluid uniformly across the surface of the top layer of the element. Any suitable fluid distribution technique may be used including, for example, particulate layers, polymeric layers, fibrous layers, woven fabric layers and liquid transport systems which have been disclosed in the art as being suitable for this purpose. Many such liquid distribution systems and materials for providing a uniform distribution of a fluid sample across the surface of an assay element are known in the art and therefore extensive discussion of such materials and systems is not required here. A particularly preferred fluid transport system is that described in commonly assigned, copending application Ser. No. 210,732, filed Jun. 23, 1988 now U.S. Pat. No. 5,051,237. The distribution means, whether a layer of fibrous material, etc. or a liquid transport system is preferably relatively thick in comparison to reagent layer 14.
In practice, the label which is present in reagent layer 14 is optically read prior to applying the sample to the assay element by irradiating layer 14 with the appropriate electromagnetic radiation through transparent support layer 12 to obtain a first readout signal. The sample fluid is then distributed across the surface of the assay element and the fluid diffuses throughout layers 14, 16 and 18 as well as any fluid distribution layer or liquid transport system present and an equilibrium is established. The analyte present in the sample will compete with the labeled analyte in reagent layer 14 for the available binding sites on the antibodies immobilized in layer 14, the labeled analyte being dissociated therefrom and replaced by the sample analyte in a ratio appropriately equal to the relative amounts of sample analyte and labeled analyte. Thus, depending upon the amount of analyte in the sample, some percentage of the labeled analyte initially bound to the immobilized antibodies in layer 14 will be displaced therefrom and distributed throughout the remainder of the assay element, The amount of labeled analyte bound to the immobilized antibodies in reagent layer 14 at any time is inversely proportional to the amount of sample analyte.
A second readout signal is obtained by again irradiating reagent layer 14 through support layer 12 with the same electromagnetic radiation used in the first optical read step to obtain a second signal which is inversely proportional to the amount of sample analyte, that is, the signal decreases as the amount of sample analyte increases. Since reagent layer 14 is relatively thin in comparison to the combined thickness of layers 16 and 18 together with that of any fluid distribution layer or liquid transport system present and because light blocking layer 16 prevents any of the readout electromagnetic radiation from entering layer 18 or anything above it, the second signal obtained will be a function of the labeled analyte which is bound to the immobilized antibodies and a small percentage of the free labeled analyte which is distributed throughout the remainder of the assay element. In a preferred embodiment the ratio of the thickness of reagent layer 14 to the combined thickness of the light-blocking layer and the remainder of the assay element is from about 1:20 to about 1:100 or more.
The ratio of the second signal to the first signal is taken and compared with that for known amounts of the analyte to determine the amount of analyte in the sample fluid. The ratio may be used as obtained or it may be multiplied by some constant, dependent upon the particular assay, to provide a signal which falls in some desired range.
In commercial use the assay is preferably carried out in an automated analytical instrument which performs the analysis automatically and records the result. By practicing the assay method of the invention variations in the instrument position response and in the thickness of the reagent layer from element to element can be compensated for and significantly better precision obtained.
The invention will now be described further in detail with respect to specific preferred embodiments by way of examples, it being understood that these are intended to be illustrative only and the invention is not limited to the materials, procedures, etc. recited therein.
EXAMPLE I
An assay element was prepared comprising a transparent polyethylene terephthalate support having coated thereon in succession:
1. a reagent layer comprising about 500 mg/m 2 of a 3:1 mixture of agarose and glyoxyl agarose; about 72 mg/m 2 of bis tris propane buffer; about 10 mg/m 2 of an antibody raised against theophylline; and about 0.07 mg/m 2 of a fluorescent labeled theophylline conjugate represented by the formula ##STR1##
2. a light-blocking layer comprising about 6000 mg/m 2 of iron oxide, about 2000 mg/m 2 of agarose and about 50.4 mg/m 2 of 2'-morpholino ethane sulfonic acid (pH 5.7); and
3. a topcoat layer comprising about 2000 mg/m 2 of agarose.
Test samples containing different levels of theophylline in a buffer solution were prepared. The buffer solution was made up of 50 mM of hydroxyethyl piperazine ethyl sulfonate (HEPES) buffer, pH 7.2, 150 mM of sodium chloride, 10 mM of EDTA and 1% of Polygeline. Each sample was run in quadruplicate.
Each assay element was inserted into a laboratory analytical instrument and conditioned at 37° C. for about two minutes. The test element was then irradiated through the transparent support with 550 nm light and the fluorescent emission measured at 580 nm. The test sample, about 10 μl, was then applied to the assay element which was incubated for an additional six minutes and then read again. The data obtained are shown in Table I. Each value shown is the average of four readings from the four quadruplicates run for each test sample. The normalized signal value was obtained by taking the values obtained from dividing the wet reading by the dry reading and multiplying them by a constant which in this case was 1.166.
TABLE I__________________________________________________________________________ DRY DRY WET WET NORMALIZED NORMALIZEDTHEOPHYLLINE SIGNAL CV SIGNAL CV SIGNAL CV(μg/dl) (V) (%) (V) (%) (V) (%)__________________________________________________________________________2.5 1.192 7.5 1.256 8.6 1.229 1.35.0 1.174 7.2 1.016 10.0 1.008 4.120.0 1.176 7.9 0.683 11.0 0.678 5.240.0 1.180 11.2 0.561 22.0 0.551 10.8__________________________________________________________________________
It is seen that normalizing the signal in accordance with the method of the invention provides significantly improved precision. Also, the data show that the improved precision was obtained at theophylline levels across the assay range (2.5-40.0 μg/dl).
EXAMPLE II
An assay element similar to that illustrated in Example I was prepared wherein the reagent layer included about 20 mg/m 2 of an antibody raised against phenytoin and about 0.15 mg/m 2 of a conjugate consisting of phenytoin bound to the fluorescent moiety illustrated in Example I.
Test samples containing 0, 5 and 40 μg/dl respectively of phenytoin were prepared in a buffer solution which was the same as that described in Example I with the exceptions that it contained about 2% BSA, about 0.01% NaN 3 and about 0.01% PNS and did not contain Polygeline.
The assay procedure was the same as that previously described. Eighteen assays were run for each concentration. The data obtained are shown in Table II. The normalized signal value was obtained by multiplying the ratio of the wet to dry readings by 3.836.
TABLE II__________________________________________________________________________ DRY DRY WET WET NORMALIZED NORMALIZEDPHENYTOIN SIGNAL CV SIGNAL CV SIGNAL CV(μg/dl) (V) (%) (V) (%) (V) (%)__________________________________________________________________________0 3.682 5.4 6.806 4.8 7.090 1.75 3.724 2.8 5.542 2.6 5.710 1.440 3.533 3.8 3.417 8.9 3.711 7.9__________________________________________________________________________
It can be seen that normalizing the signal according to the invention gave significantly improved precision.
EXAMPLE III
An assay element similar to that illustrated in Example I was prepared wherein the reagent layer included about 15 mg/m 2 of an antibody raised against phenobarbital and about 0.15 mg/m 2 of a conjugate consisting of phenobarbital bound to the fluorescent moiety illustrated in Example I.
Test samples containing 0 and 5 μg/dl, respectively, of phenobarbital in pooled human serum were prepared. The assay procedure was the same as that previously described. Three assays were carried out for each concentration. The results obtained are shown in Table III. The normalized signal value was obtained by multiplying the ratio of the wet to dry readings by 3.0.
TABLE III__________________________________________________________________________PHENO- DRY DRY WET WET NORMALIZED NORMALIZEDBARBITAL SIGNAL CV SIGNAL CV SIGNAL CV(μg/dl) (V) (%) (V) (%) (V) (%)__________________________________________________________________________0 4.112 5.13 5.002 6.08 3.648 1.245 3.886 10.66 3.462 11.56 2.671 1.05__________________________________________________________________________
The results show that normalizing the signal according to the invention provided significantly improved precision.
EXAMPLE IV
An assay element similar to that illustrated in Example I was prepared wherein the reagent layer included about 0.5 mg/m 2 of an antibody raised against T4 and about 0.01 mg/m 2 of a conjugate consisting of T4 bound to the fluorescent moiety illustrated in Example I.
Test samples containing 0.0, 2.5 and 10.0 μg/dl, respectively, of T4 in plasma (stripped of T4) were prepared. The assay procedure was the same as that previously described. Twelve assays were carried out for each concentration. The results are shown in Table IV. The normalized signal value was obtained by multiplying the ratio of the wet to dry readings by 3.0.
TABLE IV__________________________________________________________________________ DRY DRY WET WET NORMALIZED NORMALIZEDT4 SIGNAL CV SIGNAL CV SIGNAL CV(μg/dl) (V) (%) (V) (%) (V) (%)__________________________________________________________________________0 2.573 3.85 2.735 3.67 3.190 1.402.5 2.552 4.80 2.522 5.00 2.965 1.5210.0 2.512 4.42 1.907 5.97 2.276 2.14__________________________________________________________________________
The data show that significantly improved precision was obtained by normalizing the signal according to the invention.
Although the invention has been described with respect to specific preferred embodiments it is not intended to be limited thereto but rather those skilled in the art will recognize that variations and modification may be made therein which are within the spirit of the invention and the scope of the appended claims. | A method for determining the amount of an analyte in a sample fluid utilizes a multilayer assay element which comprises at least one reagent layer and a light-blocking layer. The assay method includes the steps of optically reading a signal producing species, e.g. a fluorescent label, a first time before the sample fluid is applied to the assay element and a second time, at the same wavelength and in the same location within the assay element, after the sample fluid has been applied to the assay element and the sample analyte has interacted with the reagent(s) present in the assay element. The ratio of the two signals is taken and compared with that for known amounts of the analyte to determine the amount of analyte in the sample fluid. | 8 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to disk sorting devices, particularly for sorting disks or tokens of value such as coins, and also to disk sorting assemblies and methods of handling disks.
In the following description, we will refer exclusively to the handling of coins but it should be appreciated that the invention is applicable to a wide variety of other types of disk such as medals, tokens or the like for game machines while sorting assemblies can be used in a wide variety of applications including money changers, vending machines, ticket vending machines, gaming machines, car park transaction machines, amusement machines, ‘self-service’ checkout machines, ‘back office’ coin sorting etc.
Coin dispensers typically dispense a single denomination of coin from a single coin specific store in response to a command signal. Individual hoppers can be used in conjunction to cover a wide range of denominations. The command signal might indicate a number of coins to dispense or a total value. In response to that request, the coins are fed from a storage hopper to a dispense outlet, typically via an escrow store which is first filled with coins of the required denomination and from which the coins are then released to the dispense outlet. If an error occurs, for example there are insufficient coins available, the escrow will be operated to dispense the coins to a dump store or back to the storage hopper.
There is an increasing need to improve the speed at which coins are dispensed and to allow more flexibility while providing a dispenser which is convenient to utilize and in accordance with local legal requirements. For example, in the United Kingdom, the Disability Discrimination Act (DDA) requires that coins are dispensed at a certain height range suitable for use by disabled people.
EP-A-2463217 describes a disk transferring device particularly suitable for coins which incorporates a vertical disk guide path to transfer disks from a storage hopper to an upper outlet opening. The advantage of this device is that it can be sold as a universal device to handle whichever type, in this case diameter, of disk or coin the buyer wishes to use it with. Furthermore, it operates at high speed, up to 5 coins per second, thus improving significantly upon prior art dispensers. However, it can only handle disks or coins of one type (diameter) at one time depending upon the single type of disk held within the supply hopper.
Other examples of coin sorting devices are described in WO-A-99/06969, U.S. Pat. No. 3,916,922, U.S. Pat. No. 5,145,046, and U.S. Pat. No. 5,496,212.
There is a continuing need to improve coin and disk dispensers so as to make them even more efficient.
In accordance with the first aspect of the present invention, we provide a disk sorting device comprising a housing defining a disk transport path for conveying disks from a source; a disk identifying device located adjacent the disk transport path for identifying the type of disk passing along the transport path; and a disk diverting mechanism in the disk transport path downstream of the disk identifying device and operable to divert disks in accordance with the type of the disk determined by the disk identifying device into a selected one of at least a return path in which a disk returns to the source and a dispense path in which a disk is directed towards a dispense outlet, wherein the disk transport path is oriented with a vertical component whereby disks pass along the path and the diverting mechanism under gravity, wherein the disk diverting mechanism includes a single disk diverting surface movable orthogonally with respect to the disk transport path between a first position in which a disk passes to the return path, and a second position in which a disk passes to the dispense path, wherein in one of the first and second positions the surface is retracted away from the disk transport path so that a disk can fall undeflected past the disk diverting surface and in the other of the first and second positions the surface is inserted into the disk transport path.
We have realized that the fact that a disk transferring device exists (such as described in EP-A-2463217) which can handle disks of different types, such as diameters, means not only that the device can be used with a store holding disks of the same diameter (but in which the store could be replaced with another having disks of a different diameter) but it can also be used to dispense in sequence a mixture of disks of different diameters. This allows a variety of different combinations of disks to be dispensed. However, the problem with this approach is that there is no control over which disks enter the disk reception opening and in which order. We have therefore devised a disk sorting device which can be controlled in a very simple manner to sort between the disks output from the disk transferring device so as to generate a required combination of disks at the selected one of the outlets.
One of the advantages of the disk transferring device described in EP-A-2463217 is the speed at which it can operate, as mentioned above. However, in order to operate efficiently, the disk sorting device must also be able to operate at a similar or greater speed. Conventional diverting devices using flaps and the like suffer from problems of inertia thus providing limitations on the speed of operation.
We therefore provide a novel disk diverting mechanism as described above. The diverting mechanism is very simple and just requires movement of the diverting surface orthogonally to the disk transfer path and avoids any need for a rotational or other movement subject to relatively high inertial forces. In this way, the speed of operation of the disk diverting mechanism can be matched to the rate at which disks are supplied to the disk sorting device.
In some cases, the disk diverting mechanism could be operable to place the single disk diverting surface into the disk transport path to divert disks to the return path, however preferably, when the disk diverting surface is in the first position, the surface is retracted away from the disk transport path, and when the disk diverting surface is in the second position, the surface is inserted into the disk transport path. This maximizes the speed of the return operation.
Preferably, the disk diverting surface is biased towards the retracted position so that the default configuration results in disks passing into the return path and not being inadvertently dispensed.
This approach should be contrasted with that described, for example, in WO 99/06969 in which normally coins pass to a dispense outlet and a diverter has to be switched to a different mode to cause coins to pass to the return path.
The position of the diverting surface can be controlled by means of a solenoid or pneumatic/hydraulic control although other electric/electronic motor controllers could be used such as a stepper motor.
The disk identifying device can take a variety of forms which are known conventionally and can determine different types of disk including one or more of the size, for example diameter, thickness, weight, metal content and surface appearance of the disks. Thus, the disk identifying device could be electrical and identify the different disks by the individual “electronic fingerprint” associated with a particular denomination, providing the disks disrupt an electrical field. However, if the disks have no metallic content, for example some types of gaming tokens or “chips” are 100% plastic, then the identification could be performed physically or mechanically using a roller or pairs of rollers to check diameter/thickness.
SUMMARY OF THE INVENTION
As mentioned above, the disk sorting device according to the first aspect of the invention finds particular use in a disk sorting assembly comprising a disk transferring device for transferring disks of more than one type, delivered one by one, from a disk reception opening toward a disk ejection opening, the disk transferring device including:
a disk guide path having first and second guide surfaces that guide a peripheral surface of each of the disks and third and fourth guide surfaces that guide a front surface and a back surface of a disk, the disk guide path extending from the disk reception opening toward the disk ejection opening, and
a plurality of disk pushers protruding into the disk guide path and pushing the disks by making a rotational movement about a plurality of rotational axis lines approximately at a right angle with respect to the third and fourth guide surfaces, the disk sorting device being mounted to the disk transferring device so as to receive disks from the disk ejection opening, and
a plurality of disk pushers protruding into the disk guide path and pushing the disks by making a rotational movement about a plurality of rotational axis lines approximately at a right angle with respect to the third and fourth guide surfaces, characterized in that:
the assembly further comprises a disk sorting device according to the first aspect of the invention mounted to the disk transferring device so as to receive disks from the disk ejection opening.
In the most preferred example, the disk sorting device is detachable as a unit from the disk transferring device. This means that the disk sorting device can be fitted to a pre-existing disk transferring device, for example as an upgrade feature, very easily. Of course, in other cases, the disk sorting and transferring devices could be made as a more integrated unit, for example sharing the same housing.
Preferably, the disk transport path of the disk sorting device is arranged to maintain substantially the same orientation of the disks as they have in the disk guide path. This helps to avoid any problems as disks transfer from the transferring device to the sorting device. Typically, the disk transport path and the disk guide path are arranged to maintain the faces of the disks vertically oriented. This orientation reduces the footprint of the device.
In some cases, disks are conveyed along the disk transport path of the disk sorting device by a positive feeder such as a belt or rollers but in the preferred example, the disk guide path and the disk transport path both extend generally vertically, whereby disks pass along the disk transport path under gravity. This avoids the need for any additional control mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of a disk sorting assembly and disk sorting device according to the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic side elevation of the disk sorting assembly (with some parts omitted for clarity);
FIG. 2 is a perspective view of the disk sorting assembly shown in FIG. 1 but omitting the disk sorting device;
FIG. 3 is a perspective view of the main parts of the disk transferring device shown in FIGS. 1 and 2 ;
FIG. 4 is an exploded perspective view of the main parts of the disk transferring device of FIG. 3 viewed from a front side;
FIG. 5 is an exploded perspective view of the main parts of the disk transferring device of FIG. 3 viewed from a back side;
FIG. 6 is a perspective view of the rear of the upper part of the assembly shown in FIG. 1 ;
FIG. 7 is an enlarged, perspective view of the disk diverting mechanism shown in FIG. 6 ;
FIGS. 8A-8E are views similar to FIG. 6 but with part of the disk sorting device housing removed and part of the disk diverting mechanism shown as transparent and illustrating operation of the disk sorting device; and,
FIG. 9 is a schematic, block diagram illustrating the control components of the assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The disk sorting assembly shown in the drawings is designed to feed and sort coins of a variety of denominations and hence diameter and includes a disk transferring device 1003 having a disk reception opening 1102 and disk ejection opening 1104 ( FIG. 3 ), and a disk sorting device 10 detachably mounted to the disk transferring device 1003 into which disks are fed through the disk ejection opening 1104 .
The construction of the disk transferring device 1003 is described in much more detail in EP-A-2463217 and so will only be described relatively briefly in this specification.
As can be seen in FIG. 2 , the disk transferring device 1003 comprises a disk delivering device 1002 including a hopper 900 .
For example, the disk delivering device disclosed in Japanese Unexamined Patent Application Publication No. 2001-216553 can be used.
As shown in FIGS. 3 and 4 , the disk transferring device 1003 includes a disk guide part 1100 having a disk guide path 1110 extending from the disk reception opening 1102 toward the disk ejection opening 1104 , a disk pushing mechanism 1400 having first to eighth rotary disks 1401 to 1408 provided with first disk pushers 1411 a to 1418 a and second disk pushers 1411 b to 1418 b , respectively, and a rotational driving device 1500 for rotationally driving the disk pushing mechanism 1400 .
As shown in FIGS. 3 and 4 , the disk guide part 1100 is configured of a base part 1200 and a top plate 1300 provided on the base part 1200 .
The base part 1200 is formed of a structure in which a flat-shaped first member 1206 has a second member 1208 placed thereon, and a through hole 1215 is formed in the second member 1208 . The through hole 1215 has a flat shape with eight circular apertures connected in a zigzag manner, and has a recessed part 1216 that can accommodate the disk pushing mechanism 1400 on a front surface 1202 side of the base part 1200 .
On a bottom surface 1218 of the recessed part 1216 , first to eighth rotating shafts 1231 to 1238 are provided having first to eighth rotational axis lines 1221 to 1228 approximately at a right angle with respect to the front surface of the base part 1200 . The first to eighth rotating shafts 1231 to 1238 are fixed to fixing screws inserted in screw holes from the back surface 1204 side of the base part 1200 via the first member 1206 .
As shown in FIGS. 4 and 5 , the top plate 1300 has a front surface 1302 and a back surface 1304 parallel to each other, and is fixed to the base part 1200 with the back surface 1304 being placed on the front surface 1202 of the base part 1200 . The front surface 1302 and the back surface 1304 of the top plate 1300 is approximately at a right angle with respect to the first to eighth rotational axis lines 1221 to 1228 .
On the back surface 1304 side of the top plate 1300 , a disk guide groove 1306 extending from the disk reception opening 1102 to the disk ejection opening 1104 is formed. The disk guide groove 1306 has a bottom surface 1310 and first and second side surfaces 1312 and 1314 , and the bottom surface 1310 is approximately at a right angle with respect to the first to eighth rotational axis lines 1221 to 1228 .
The disk guide groove 1306 has a width wg and a depth dg that are set so as to be slightly larger than the width and depth of a disk to be transferred. In other words, the width wg and the depth dg of the disk guide groove 1306 are set so that the disk to be transferred can pass through the inside the disk guide groove 1306 as being guided with the bottom surface 1310 and the first and second side surfaces 1312 and 1314 . Note that when a plurality of denominations of disks with different diameters and thickness are transferred, the width wg and the depth dg of the disk guide groove 1306 are set according to a maximum diameter and a maximum thickness of the disks.
The first side surface 1312 is formed along a curve 1318 with a plurality of segments of circles centering on the second, fourth, sixth, and eighth rotational axis lines 1222 , 1224 , 1226 , and 1228 connected together. The second side surface 1314 is formed along a curve 1316 with a plurality of segments of circles centering on the first, third, fifth, and seventh rotational axis lines 1221 , 1223 , 1225 , and 1227 connected together.
Furthermore, on the back surface 1304 of the top plate 1300 , an annular groove 1322 preventing a contact of first disk pushers 1411 a to 1418 a and second disk pushers 1411 b to 1418 b , which will be described further below, with the top plate 1300 when these disk pushers make a rotational movement is provided, correspondingly to the respective first to eighth rotational axis lines 1221 to 1228 .
The disk guide path 1110 is configured of the front surface 1202 of the base part 1200 , the bottom surface 1310 of the disk guide groove 1306 of the top plate 1300 , and the first and second side surfaces 1312 and 1314 . In other words, the front surface 1202 of the base unit 1200 functions as a back guide surface 1118 of the disk guide path 1110 , the bottom surface 1310 of the disk guide groove 1306 of the top plate 1300 functions as a front guide surface 1116 of the disk guide path 1110 , and the first and second side surfaces 1312 and 1314 of the disk guide groove 1306 of the top plate 1300 function as left and right guide surfaces 1112 and 1114 of the disk guide path 1110 . In the disk guide path 1110 , the peripheral surface of a disk introduced from the disk reception opening 1102 is guided with the left and right guide surfaces 1112 and 1114 of the disk guide path 1110 (that is, the first and second side surfaces 1312 and 1314 of the disk guide groove 1306 ). Also, on an front surface and a back surface of a disk are guided with the front and back guide surfaces 1116 and 1118 of the disk guide path 1110 (that is, the bottom surface 1310 of the disk guide groove 1306 and the front surface 1202 of the base part 1200 ).
As shown in FIGS. 4 and 5 , the disk pushing mechanism 1400 has the first to eighth rotary disks 1401 to 1408 having the first to eighth rotating shafts 1231 to 1238 , respectively, inserted therein. The first to eighth rotary disks 1401 to 1408 each have an approximately circular outer shape in a planar view, and are each rotatably supported in the corresponding first to eighth rotating shafts 1231 to 1238 in both forward and reverse directions. In other words, the first to eighth rotary disks 1401 to 1408 can rotate about the corresponding first to eighth rotational axis lines 1221 to 1228 , respectively.
The first to eighth rotary disks 1401 to 1408 are provided with the first disk pushers 1411 a to 1418 a and the second disk pushers 1411 b to 1418 b , respectively, as a pair, each disk pusher having a columnar outer shape. That is, in a peripheral part 1424 of the first rotary disk 1401 , the first and second disk pushers 1411 a and 1411 b protruding from the front surface 1422 of the rotary disk 1401 are provided. The first and second disk pushers 1411 a and 1411 b are arranged so as to interpose the first rotating shaft 1231 . In other words, the first and second disk pushers 1411 a and 1411 b are arranged on a straight line passing through the first rotational axis line 1221 on the first rotary disk 1401 .
Also for the second to eighth rotary disks 1402 to 1408 , as with the first rotary disk 1401 , in the peripheral parts 1424 of the second to eighth rotary disks 1402 to 1408 , the first and second disk pushers 1412 a and 1418 a and 1412 a to 1418 b protruding from the front surfaces 1422 of the second to eighth rotary disks 1402 to 1408 , respectively, are provided. The first and second disk pushers 1412 a to 1418 a and 1412 b to 1418 b are arranged so as to interpose the rotating shafts 1232 to 1238 , respectively. In other words, the first and second disk pushers 1412 a to 1418 a and 1412 b to 1418 b are arranged on straight lines passing through the second to eighth rotational axis lines 1222 to 1228 on the second to eighth rotary disks 1402 to 1408 , respectively.
When the first to eighth rotary disks 1401 to 1408 are rotated, the first and second pushers 1411 a to 1418 a and 1411 b to 1418 b make a rotational movement about the first to eighth rotational axis lines 1221 to 1228 , respectively.
The rotational driving device 1500 has an electric motor 1502 and a decelerating mechanism 1504 having connected thereto a driving shaft (not shown) of the electric motor 1502 . An output shaft (not shown) of the decelerating mechanism 1504 is connected to the first rotating shaft 1231 . The first rotary disk 1401 and the first gear wheel 1431 are connected to the output shaft of the decelerating mechanism 1504 via the first rotating shaft 1231 .
For the first gear wheel 1431 to be caused to function as a driving gear wheel, the first rotary disk 1401 and the first gear wheel 1431 are fixed to the first rotating shaft 1231 . Therefore, when the electric motor 1502 is activated, the rotation of the driving shaft of the electric motor 152 is transmitted via the decelerating mechanism 1504 to the first rotating shaft 1231 , thereby rotating the first rotary disk 1401 and the first gear wheel 1431 . Since adjacent ones of the first to eighth gear wheels 1431 to 1438 engage with each other, the rotation of the first gear wheel 1431 is transmitted to the second to eighth gear wheels 1432 to 1438 sequentially. That is, the second to eighth gear wheels 1432 to 1438 function as driven gear wheels. As such, the disk pushing mechanism 1400 is driven, thereby causing the first to eighth rotary disks 1401 to 1408 to rotate and causing the first and second disk pushers 1411 a to 1418 a and 1411 b to 1418 b to make a rotational movement.
As explained in more detail in EP-A-2463217, rotation of the disks 1401 - 1408 causes disks or coins to be fed from a hopper 900 up through the disk transferring device to the disk ejection opening 1104 .
As can be seen in FIG. 1 , the disk ejection opening 1104 opens into a disk transport path 20 formed within a housing 22 of the disk sorting device 10 . The disk sorting device is detachably secured to the housing of the disk transferring device 1003 by brackets 40 ( FIG. 6 ) and bolts (not shown).
At the entrance to the disk transport path 20 is provided a coin sensing coil 24 which is wound around the housing 22 and through which each coin or disk will pass as it enters the disk transport path 20 . This coil forms the inductive element of a Colpitts oscillator circuit (not shown). As a coin passes through the coil, the inductance increases and this increase causes a change in the oscillator's frequency and amplitude. The amount and type of change allows the coin to be identified by a control PCB (not shown) in a conventional manner.
In a modification (not shown) a second coin sensing coil similar to the coil 24 is provided in a substantially horizontal orientation around a vertically extending part of the transport path 20 upstream of a coin entry sensor 26 (to be described). This helps to improve the coin identification performance.
The coin then falls under gravity through the disk transport path 20 and passes the coin entry sensor 26 located upstream of a disk diverting mechanism 28 .
The disk diverting mechanism 28 comprises a solenoid 30 having an axially movable actuator 32 . The solenoid is typically a push/pull, 24V DC solenoid, type 341C manufactured by Densitron/Geeplus and can move the actuator 32 between its two positions in about 22 milliseconds. This is much faster than the shortest time between successive coins fed by the disk transferring device (⅕ seconds or 200 milliseconds).
The disk diverting mechanism further includes a diverter member or gate 34 non-rotatably attached to the actuator 32 so that it can be moved orthogonally with respect to the disk transport path 20 between a first position in which coins can pass undiverted to a first, return outlet 36 , and a second position in which it diverts coins to a second dispenser coin outlet 38 .
As mentioned above, as alternatives to the solenoid 30 , it is possible to use a pneumatically controlled actuator, a stepper motor or the like.
The advantage of diverters according to the invention over conventional flap operated diverters is that there is less inertia involved as compared with a flap based diverter and thus they can be operated more quickly and efficiently and thus match the feed speed of the disk transferring device 1103 .
As can be seen in FIG. 2 , the coin outlet 36 cooperates with a guide plate 70 so that coins ejected through the outlet 36 will slide down the guide plate 70 back into the hopper 900 . On the other hand, coins passing out of the dispense outlet 38 will pass to a dispense position (not shown) where they can be retrieved by an operator.
The actuator 32 is biased by a compression spring or the like (not shown) towards its first position so that as a default, coins will fall towards the coin outlet 36 for return to the hopper 900 and this avoids inadvertent dispense.
FIG. 6 illustrates an upper part of the disk sorting device 10 and in particular the way in which the disk diverting mechanism 28 is mounted. Thus, this mechanism 28 includes a mounting bracket 42 to which is attached the solenoid 30 . The bracket 42 is secured to the housing 22 as shown. The actuator 32 has the diverter member 34 attached to its end which is thus supported by the solenoid 30 for movement to and fro orthogonal to the housing 22 and bracket 42 .
As can be seen in FIG. 7 , the diverting member 34 is formed by two side plates 46 A and 46 C secured together in a spaced apart configuration with a dividing bar 46 B between them to define a pair of guide slots 48 A and 48 B respectively. The guide slot 48 A is fully open at its lower end along the length of the member 34 while the guide slot 48 B has a web 50 located along part of its base to define a coin diverting surface 52 .
FIG. 8A-8E are similar to FIG. 6 but with the housing plate facing the viewer removed and hence the solenoid 30 is not visible.
In FIG. 8A , the actuator 32 is in its rest or first position, spring biased to bring the slot 48 A into alignment with the disk transport path 20 . In this position, a coin 60 arriving at the diverting member 34 passes through the slot 48 A undiverted towards the outlet 36 and hence back to the hopper 900 via the guide plate 70 . This process can be seen further in FIG. 8B which also shows the arrival of a second coin 62 which also is to pass to the hopper 900 .
FIGS. 8C-8E illustrate the operation of the disk sorting device when a disk is to be diverted to the dispense outlet 38 . In this case, the solenoid 30 is activated to move the actuator 32 against the spring bias which causes the diverting member 34 to be moved so as to bring the web 50 into alignment with the path 20 .
As can be seen in FIG. 8D , a coin 64 arriving at the diverting member 34 passes into the slot 48 B and engages the diverting surface 52 . This causes the coin 64 to roll to the right (as seen in FIG. 8D ) and to then drop down into the outlet 38 . This can be seen again in FIG. 8E which also shows the arrival of the next coin 66 which also has to be diverted into the outlet 38 .
Associated with each outlet 36 , 38 is a respective coin sensor 70 , 72 which detects the passage of coins into the respective outlets and thus can determine the presence of a jam if that should occur.
The coin entry sensor 26 is used to time operation of the solenoid 30 if required although depending upon the length of the path 20 , the sensor 26 could be omitted and timing controlled from detection of coins by the coil 24 . Indeed, in some embodiments, the sensors 70 , 72 could also be omitted.
The outlet 38 is connected to a dispense opening or alternatively could be connected to an escrow store which itself then dispenses coins either to a dispense outlet or back to the hopper 900 via ducts (not shown).
It is also envisaged that more than two outlets could be provided together with a suitable diverting device.
FIG. 9 is a block diagram illustrating the control components of the device shown in FIGS. 1 to 8 . As can be seen, each of the coin entry sensors 26 , coin exit sensors 70 , 72 and solenoid 30 are connected to a disk sorting device CPU 50 which is also connected to the coin sensor 52 of which the coil 24 forms a part. The CPU 50 responds to control signals from the main controller 54 of the overall assembly so that the correct combination of coins is dispensed from the outlet 38 .
The assembly can be operated in a variety of ways. In the preferred approach, the main controller 54 specifies which coins to use to make up the correct total value which is to be dispensed. Typically, the main controller 54 will monitor the quantity of each coin type held in the hopper 900 and can therefore determine which combination of coin types are available although this is not essential, particularly if the outlet 38 feeds to an escrow store. In any event, in a typical case, the main controller 54 will indicate to the CPU 50 that say two coins of a first type and three coins of a second type should be dispensed. (In this case “type” means “diameter” although many other means may be used to determine the value of a coin as mentioned above.) The disk transferring device 1003 is then activated and the coins are fed to the disk ejection opening 1104 and into the disk sorting device 10 . The coin sensor 52 detects the coin type, typically by determining its diameter and hence its value, and this information is fed to the CPU 50 . If the coin is to form part of the dispense then the CPU 50 will monitor for the arrival of the coin at the coin entry sensor 26 and either immediately or after a predetermined time interval, will activate the solenoid 30 to insert the diverter gate 34 into the guide path 20 so that the coin is diverted into the outlet 36 . The passage of the coin into the outlet 36 is detected by the coin exit sensor 70 and providing that passage is confirmed, the solenoid 30 will then be deactivated and the diverter gate 34 will return under spring action to its retracted position.
If the coin sensor 52 identifies a coin which is not to be dispensed, for example it is of a type not required or sufficient coins of that type have been dispensed, then the CPU 50 will not activate the solenoid 30 and the coin will fall under gravity through the guide path 20 to the outlet 38 and back to the hopper 900 .
In an alternative mode of operation, the main controller 54 will simply indicate the value which is to be dispensed and the appropriate combination of coins will be determined by the CPU 50 . For example, if a value of £1 is to be dispensed, the CPU 50 will decide as each coin is identified by the coin sensor 52 how much value remains to be dispensed and will therefore vary the coins which form that dispense combination depending upon the coins that have been dispensed to date. This may, however, mean a less efficient operation due to the random nature in which coins are dispensed from the hopper. | A disk sorting device includes a housing defining a disk transport path for conveying disks from a disk transferring device. A disk identifying device is located adjacent the disk transport path for identifying the type of disk passing along the transport path. A disk diverting mechanism in the disk transport path downstream of the disk identifying device is operable to divert disks in accordance with the type of the disk determined by the disk identifying device into a selected one of at least a return path in which a disk returns to the disk transferring device and a dispense path in which a disk is directed towards a dispense outlet. The disk transport path is oriented with a vertical component whereby disks pass along the path and the diverting mechanism under gravity. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a thermally insulating shipping container including a bottom piece, two longitudinal side pieces, two transverse side pieces and at least one cover piece, which enclose a shipping chamber and are made of an insulating material.
2. Discussion of Related Art
Thermally insulating shipping containers are known and are extensively used, for example, for shipping temperature-sensitive foods, such as frozen food, or also for shipping warm food. For the purpose of efficient and cost-effective production, along with good thermal insulation properties, such shipping containers are often integrally produced from a molded particle foam on the basis of a polyolefin, such a polypropylene, so-called EPP, or also on the basis of polystyrene, so-called EPS.
However, in connection with known shipping containers, it has been found to be disadvantageous that, because of their integrally one-piece manufacture, they are very bulky when not in use and thus require a large shipping volume.
On the other hand, shipping containers are known which do not have a thermally insulating function and which, when not in use, can be folded in a space-saving manner. However, the folding mechanisms employed cannot be transferred to the previously discussed thermally insulating shipping containers, because the hinged connections, which customarily comprise hinged shafts and hinged bearings for the foldable connection of the individual parts, cannot be applied to or embodied as foamed EPP or EPS parts.
SUMMARY OF THE INVENTION
One object of this invention is to provide a thermally insulating shipping container of the type mentioned above but which has good insulation properties and occupies only a small volume when not in use, is easy to manufacture and has a large carrying capacity and stability in the unfolded state.
To attain the object, this invention relates to a thermally insulating shipping container having characteristics described in this specification and in the claims.
In accordance with this invention, the longitudinal side pieces and the transverse side pieces are pivotably maintained on the bottom piece around respective pivot axes, which extend parallel with respect to the bottom piece, so that they can be unfolded from a folded orientation, which extends parallel with respect to the bottom piece, into an orientation which is perpendicular to it, in which they enclose the shipping chamber and in which the shipping chamber can be subsequently closed by the at least one cover piece. Thus, in accordance with this invention, a bottom piece is proposed as a central element, on which the longitudinal and transverse side elements are pivotably fastened or maintained, such as all connecting elements required for this can be integrated into the bottom piece and correspondingly in the longitudinal and transverse side pieces, which leads to a particularly sturdy shipping container in the unfolded state.
In one embodiment of the shipping container in accordance with this invention, the bottom piece has a right-angled bottom area, wherein a corner protrusion, whose top projects upward, is formed in each corner area of the bottom piece. On its sides facing the longitudinal and transverse side pieces, each one of the corner protrusions has integrally molded hinge elements, which can be brought into an operational connection with correspondingly formed hinge elements of the longitudinal and transverse side walls. Accordingly, the corner protrusions of the bottom piece provide holding and pivotable linkage of the longitudinal and transverse side pieces at the bottom piece. Also, the corner protrusions can also be used as stops for the longitudinal and transverse side pieces brought into an unfolded position, for example placed perpendicularly with respect to the bottom piece, so that further unfolding is prevented by a stop against the corner protrusions, and a dimensionally stable shipping container is created.
In order to continue to be able to produce the thermally insulating shipping container in accordance with this invention with an efficient mode of production from a molded particle foam, the hinge elements are preferably integrally molded in the bottom piece and the longitudinal or transverse side walls.
In one embodiment of this invention, the longitudinal and transverse side walls are in the form of spherical heads or universal ball joint-shaped heads, which are maintained, pivotable around the hinge axes, in correspondingly embodied ball sockets provided, for example, in the area of the corner protrusions. However, the opposite arrangement is also possible, such as the ball sockets are integrally molded in the longitudinal and transverse side walls, while the corresponding spherical heads seated therein are molded in the bottom piece, preferably in the area of the corner protrusions. It is thus possible to omit additional parts, such as hinge shafts, which possibly require different materials.
It is also possible to provide heads in the shape of a truncated cone and corresponding linkage recesses in place of heads in the shape of a universal ball joint.
Not employing other materials does not only make sense from the viewpoint of economy of manufacture, because in this case additional assembly steps are saved. Further, the omission of additional materials makes possible recycling of only one type, or the easy disposal of a no longer required shipping container in accordance with this invention.
In one embodiment of this invention, the at least one cover piece can be placed on top of the unfolded longitudinal and transverse side pieces for closing the shipping chamber at the top. The shipping container in accordance with this invention has additional stiffening by the cover piece which, in the unfolded orientation of the longitudinal and transverse side pieces, can be placed on top of it, so that its sturdiness in the unfolded state approaches that of a shipping container formed in one piece.
Two cover pieces are provided in another possible embodiment of this invention, which together provide the closure at the top of the shipping chamber. Particularly advantageously, it is possible to provide pivotable fixation of each cover piece on one of the transverse side pieces, so that the cover pieces are not only connected with the further parts of the shipping container in accordance with this invention in a way in which they cannot be lost, but that, in the folded state of the transverse side pieces, they can also be folded in a space-saving manner above or below the transverse side pieces in a parallel orientation with respect to the latter.
Here, the cover pieces can be maintained, pivotable around hinge axes, on the transverse side pieces by linkage heads held in hinge elements in the form of hinge recesses, wherein the hinge elements are respectively integrally molded in the cover pieces and the transverse side pieces. For example, the linkage heads can have the shape of universal ball joints or truncated cones. In this way, the shipping container in accordance with this invention also makes do without additional hinge pieces, such as shafts, bushings, and the like and can be produced true-to-type, for example by known molded foam methods, in a single work step.
Within the framework of this invention, exterior carrying handles can be on the longitudinal and/or transverse side walls of the shipping container in accordance with this invention, to cause the user to carry and handle the shipping container in accordance with this invention, along with its possibly considerable filling weight, at defined locations which are particularly suitable for the transfer of force.
In accordance with a suggestion of this invention, it is possible to provide attachment strips, which respectively protrude at the top from the bottom piece, between two adjoining corner protrusions used for the hinged holding of longitudinal or transverse side walls, which strips are provided on their sides facing the respective corner protrusions with corresponding hinge elements, such as with the corner protrusions. Accordingly, the hinge elements are used to come into operational connection with correspondingly formed hinge elements of the longitudinal or transverse side walls, so that a particularly large degree of stability is achieved by this dual joint connection, and the longitudinal and transverse side walls are prevented from being released in an undesired manner from the hinge connection, even if a large load is absorbed inside the shipping container.
In accordance with a further embodiment of this invention, the longitudinal side walls are equipped with means for the snap-in reception of the transverse side walls in the unfolded orientation. Accordingly, if the shipping container in accordance with this invention is raised into its position of use by successively occurring unfolding of the longitudinal side walls and the transverse side walls, further increased stability is achieved by the snapped-in reception of the unfolded transverse side walls between the longitudinal side walls, wherein this snapped-in orientation of the longitudinal and transverse side walls can only be cancelled by a definite use of force, but is safe from accidental folding.
Also, the longitudinal and/or transverse side walls can be embodied with insertion strips which, in the unfolded orientation, are arranged at the top and can be inserted into corresponding insertion grooves formed at the bottom of at least one cover piece, so that the at least one cover piece can be positively attached to the top of the longitudinal and transverse side walls arranged in the unfolded orientation, and the cover piece is not only maintained secure against loss, but a positive connection, which increases the stability of the shipping container, is also achieved.
Other snap-in and locking options of the at least one cover piece on the longitudinal and transverse side walls arranged in an unfolded orientation are also possible within the framework of this invention. Within the framework of this invention, it is also possible to maintain the cover piece pivotably on the longitudinal and transverse side walls, wherein in such embodiments the cover piece can be of several pieces.
For arranging the shipping container in accordance with this invention and its individual parts as a compact unit also in the folded state, and to protect it from damage, the height of the corner protrusions extending in height above the bottom surface of the bottom piece is preferably of such a size, that at least the lateral side walls and the longitudinal side walls can be received in a parallel orientation with respect to the bottom piece between these corner protrusions. In this orientation the upper edge of the corner protrusions terminates flush with the cover piece placed on the longitudinal and transverse side walls.
The shipping container of this invention can preferably be produced from a molded particle foam, known per se, which has a particularly good thermal insulating effect and has a predominantly closed-cell foam structure, on the basis of a polyolefin, such as polyethylene or polypropylene, or on the basis of polystyrene. However, other material selections are also possible within the framework of this invention.
However, it is preferable if the shipping container is made of molded foam particles of an apparent density of at least 30 kg/m 3 , wherein the wall thickness of the bottom piece, the longitudinal and transverse side pieces and the cover piece should be in the range between 15 to 35 mm, preferably 25 to 30 mm.
In an alternative embodiment of the shipping container in accordance with this invention, if from molded parts, containing hollow chambers, on the basis of thermoplastic materials, can be produced in a cost-effective manner, and can have a great insulating effect because of their hollow chambers that are extremely sturdy. In such embodiment of the shipping container in accordance with this invention of molded parts, wall thicknesses of approximately 0.5 to 2 mm are preferably provided, if the molded parts are made of polypropylene. Such molded parts can be produced, for example, by a blow-molding method, wherein the hinge elements can also be integrally molded.
Also, the surfaces of the shipping container in accordance with this invention can have a liquid-proof coating, for example a foil, which is placed into the tool during the molded foam process and is integrally connected with the molded foam particles and that then forms the surface of the produced molded parts. A shipping container in accordance with this invention, produced from such surface-coated parts, can be easily washed off if dirty and, with an appropriate shaping of the bottom piece, can also form a leak-proof catch basin for liquid possibly exiting the materials shipped in the shipping chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Further embodiments and details of this invention will be explained in greater detail in view of an exemplary embodiment shown in the drawings, wherein:
FIG. 1 a is a perspective view of a first embodiment of the shipping container in accordance with this invention, in the unfolded state;
FIG. 1 b is a perspective view of the shipping container in accordance with FIG. 1 , in the folded state;
FIG. 2 is a perspective view of the bottom piece of the shipping container, in accordance with FIGS. 1 a and 1 b;
FIG. 3 a is a perspective view of the transverse side piece of the shipping container in accordance with FIGS. 1 a and 1 b;
FIG. 3 b is a perspective view of the transverse side piece in accordance with FIG. 3 a in a further perspective representation;
FIG. 4 shows a longitudinal side piece of the shipping container in accordance with FIGS. 1 a and 1 b , in a perspective view;
FIG. 5 shows a cover piece of the shipping container in accordance with FIGS. 1 a and 1 b , in a perspective view;
FIG. 6 shows a top view from above on the shipping container with the cover pieces removed;
FIG. 7 shows a perspective view of two shipping containers stacked on top of each other, each in the unfolded state, in accordance with FIG. 1 a;
FIG. 8 shows a perspective view of two shipping containers stacked on top of each other, each in the folded state, in accordance with FIG. 1 b;
FIG. 9 shows a perspective view of a further embodiment of the bottom piece of a shipping container in accordance with this invention;
FIG. 10 shows a perspective view of a further embodiment of a transverse side piece of a shipping container in accordance with this invention; and
FIG. 11 shows a perspective view of a further embodiment of the shipping container in accordance with this invention with pieces in accordance with FIGS. 9 and 10 .
DETAILED DESCRIPTION OF THE INVENTION
A thermally insulating shipping container is represented in FIGS. 1 to 6 , which includes a bottom piece 1 , two longitudinal side pieces 2 , two transverse side pieces 4 and a two-piece cover piece 6 a , 6 b , which can be placed, parallel with the bottom piece 1 , on the longitudinal and transverse side pieces 2 , 4 , so that in the position of use a shipping chamber is enclosed.
The thermally insulating effect of the shipping container is a result of the above mentioned pieces being produced from a thermally insulating material, for example EPP of an apparent density of at least 30 kg/m 3 and a wall thickness of preferably 25 to 30 mm and with a predominantly closed-cell foam structure.
The shipping container represented in the drawing figures during non-use can be folded together in a space-saving manner, as shown in FIG. 1 b , and can be unfolded for use, as will be explained in greater detail in this specification and as shown in FIG. 1 a.
The basis, or the basic element of the shipping container is the bottom piece 1 , whose details are shown in FIG. 2 .
The bottom piece 1 has a rectangular bottom area 10 , wherein an upwardly projection corner protrusion 11 is molded in each corner area of the bottom piece 10 .
Two attachment strips, shaped in the manner of stair steps and projecting from the top and identified by the reference numeral 12 , can be seen between adjoining corner protrusions 11 along oppositely located edge areas of the bottom piece 10 . The edge areas of the bottom piece 10 containing the attachment strips 12 face the longitudinal side pieces 2 , the closer details of one of which are shown in FIG. 4 .
Now, in order to assure a foldable or unfoldable orientation of the longitudinal and transverse side pieces 2 and 4 on the bottom piece 1 , such as shown in FIG. 1 a or 1 b , each corner protrusion 11 of the bottom piece 1 has hinge elements in the form of spherical or half-shell-shaped linkage recesses, which can also be called ball sockets 14 , 15 , on its sides facing the longitudinal or transverse side pieces 2 , 4 . Here, the ball sockets identified by the reference numeral 14 face the longitudinal side wall 2 , for example they are molded in the corner protrusions 11 in the direction of the attachment strips 12 of the bottom piece 1 , while the ball sockets identified by the reference numeral 15 face the transverse side walls 4 and are molded at right angles with respect to the ball sockets 14 in the corner protrusions 11 .
One essential characteristic of these hinge elements in the form of ball sockets 14 , 15 is that they are integrally molded in the corner protrusions 11 , so that the one-piece manufacture of the bottom piece 1 , such as shown in FIG. 2 , of the shipping container by a molded foam process of expanded polypropylene particle foam or expanded polystyrene (EPP or EPS) is made possible without requiring additional materials or individual parts.
For being pivotably held on the bottom piece 1 embodied in this way, the longitudinal side walls 2 , such as shown in FIGS. 4 a and 4 b , are embodied with a hinge strip 24 which, in the unfolded orientation, is arranged on the underside and extends past or beyond the lateral face 20 . Corresponding to the ball sockets 14 provided for this, half-shell-shaped or universal ball joint-shaped spherical heads 240 , which project from the corner protrusions 11 and can be inserted into oppositely located ball sockets 14 of adjoining corner protrusions 11 parallel with an attachment strip 12 , are integrally molded on the hinge strip 24 at the two front ends of the hinge strip 24 on the underside. Therefore the longitudinal side pieces 2 , together with their hinge elements in the form of spherical heads 240 , can also be produced in one piece, for example by a molded foam process.
In the same way, the transverse side pieces 4 shown in FIGS. 3 a and 3 b are embodied with a hinge strip 44 which, in the unfolded orientation, projects on the underside past the lateral face 40 and has a lesser width, which again has half-shell-shaped spherical heads 440 as hinge elements on its two front ends, which can be inserted into correspondingly provided ball sockets 15 between two adjoining corner protrusions 11 of the bottom piece 1 .
As shown in FIG. 2 , the ball sockets 15 used for receiving the spherical heads 440 of the transverse side pieces 4 can be arranged with respect to the bottom area 10 of the bottom piece at a greater height than the ball sockets 14 used for receiving the spherical heads 240 of the longitudinal side pieces 2 , and thus as can be seen in FIG. 1 b , can arrange the two longitudinal side pieces 2 on the bottom area 10 in a folded orientation, such as extending parallel with respect to the bottom piece 1 and its bottom area 1 Q, and to also arrange thereon the two transverse side pieces 4 , also in a parallel orientation with respect to the bottom area 10 of the bottom piece 1 . Then it is possible to place the cover pieces 6 a or 6 b , visible in FIG. 5 , on this arrangement of transverse side pieces 4 and longitudinal side pieces 2 , wherein the height of the corner protrusions 11 is preferably selected so that they then terminate flush with the top of the folded-up transverse side pieces 4 , and the transverse side pieces 4 and the longitudinal side pieces 2 are received between the corner protrusions 11 . In this folded orientation, the shipping container in accordance with FIG. 1 b needs only little storage space.
If used in accordance with its purpose, for example to enclose a shipping chamber in which temperature-sensitive material can be shipped, the longitudinal and transverse side pieces 2 , 4 are placed into a folded-open position, which can be seen in FIG. 1 a . First, starting with the folded state in accordance with FIG. 1 b , the transverse side pieces 4 with the cover pieces 6 a , 6 b , which are fastened on them in a manner yet to be described, are raised into a vertical position. In the process, unfolding takes place around a pivot axis S 4 , which is defined by the hinge elements in the form of the ball sockets 15 and the spherical heads 440 and extends at right angles in relation to the pivot axis S 2 of the longitudinal side pieces 2 .
Now the longitudinal side pieces 2 can be reached, which are accessible above the bottom piece 1 and are in the folded-up orientation, such as extending parallel with the bottom area 10 . Because of their pivotable seating between the ball sockets 14 of the corner protrusions 11 and the spherical heads 240 , they are now raised on the hinge strips 24 of the side pieces 2 around a pivot axis identified by S 2 into an orientation extending vertically with respect to the bottom area 10 of the bottom piece 1 , in which, with a contact protrusion 2 a on their underside, they come into contact with the respective attachment strip 12 , so that they assume an exactly right-angled orientation with respect to the bottom piece 1 .
It is understood that the respective heights of the longitudinal and transverse side pieces 2 , 4 in the unfolded state should be matched, i.e. should be identical, and the heights should be selected so that the oppositely located longitudinal side walls 2 or transverse side walls 4 can be folded completely over the bottom piece 1 .
After the longitudinal and transverse side pieces 2 , 4 thus designed are brought into their unfolded orientation, such as extending vertically with respect to the bottom area 10 of the bottom piece 1 , the shipping container in accordance with FIG. 6 can be filled and, following this, the cover pieces 6 a , 6 b can be placed on the top edge areas of the side pieces 2 , 4 , in order to close the shipping chamber inside the shipping container. For this purpose, the longitudinal side walls 2 have top insertion strips 21 along their edge areas which are on top in the unfolded orientation, which strips positively engage correspondingly designed grooves 61 on the underside of the cover piece 6 , in the cover pieces 6 a , 6 b as shown in FIG. 1 b . A shipping container unfolded in this way and plugged together by positive connections has extremely high sturdiness and stability and can be used for shipping even heavy sensitive materials.
Moreover, all performed positive locking processes and also the pivot movements are reversible, i.e. following its use the shipping container can again be folded into its folded, space-saving orientation as shown in FIG. 1 b , and is therefore suitable for repeated or returnable use.
Although it would be possible to only provide a single cover piece which can be applied and removed, the shipping container preferably has a multi-section cover piece, comprising two cover pieces 6 a , 6 b , wherein the two cover pieces 6 a , 6 b each cover approximately one-half of the shipping chamber in the interior of the shipping container and together cover it on the top in the orientation shown in FIG. 1 a.
Also, the two cover pieces 6 a , 6 are pivotably held on the horizontal edge of the transverse side pieces 4 which lie on top in the folded-open state of the transverse side pieces 4 .
For this purpose, each pair of transverse side pieces 4 , whose greater details can also be seen in FIGS. 3 a and 3 b and which, in their folded-open state, lie on top, has hinge receptacles 400 , which are each spaced apart by an interspace 400 a.
Linkage recesses 401 are integrally formed out of the facing inner surfaces of the respective pairs of hinge receptacles 400 which, for defining an insertion channel, are upwardly widened in the shape of a step or in the shape of a ramp, which is indicated by the reference numeral 401 a.
Correspondingly, the two cover pieces, for example the cover piece 6 b shown in FIG. 6 , have a hinge element 63 , which is integrally molded on the cover piece 6 b and fits into the interspace 400 a and on whose two sides facing the linkage recesses 401 protruding linkage heads 630 of a truncated-cone shape are molded, so that, without the addition of separate hinge elements, a pivotable seating of the two cover pieces 6 a , 6 b on the transverse side pieces 4 can be provided by the integral shaping of the hinge elements formed in this way. A ramp-shaped flattening 630 a is provided for easy introduction of the linkage heads 630 into the linkage recesses which, together with the insertion channels 401 a , makes possible the easy attachment and, if required, also the removal, of the cover pieces 6 a , 6 b.
The hinge connection realized in this process between the transverse side pieces 4 and the respective cover pieces 6 a , 6 b defines pivot axes S 6 parallel with respect to the pivot axes S 4 of the transverse side pieces 4 , which assure the pivotability of the cover pieces 6 a , 6 b by at least 270°.
Because of this great pivot angle it is not only possible, as shown in FIG. 1 a , to place the cover pieces 6 a , 6 b on the upper edge area of the longitudinal and transverse side pieces 2 , 4 for closing the shipping chamber, but also to fold them open for access to the shipping chamber which is made easier by forming out grip recesses 64 on the top of the cover pieces 6 a , 6 b.
If, for the purpose of returning or because of non-use, the shipping container thus designed, as shown in FIG. 1 b , first, following the folding open of the cover pieces 6 a , 6 b , folding of the longitudinal side pieces 2 into an orientation extending parallel with respect to the bottom piece 1 is provided in the already explained way by the pivotable seating of the transverse side pieces 4 around the pivot axis S 2 on the bottom piece 1 . Thereafter, the two cover pieces 6 a , 6 b are brought out of their position represented in FIG. 7 a into a parallel position with respect to the transverse side pieces 4 , which are still in the unfolded state, on the two facing outsides of the same and, as a result of their already mentioned pivotable seating around the pivot axis S 4 , subsequently the transverse side pieces 4 are brought into their position which is shown in FIG. 1 b , in which they come to rest in a space-saving manner parallel with the previously folded-in longitudinal side pieces 2 and the bottom piece 1 . The cover pieces 6 a , 6 b rest above and parallel with the transverse side pieces 4 .
As shown in FIGS. 1 a and 2 , in an edge area between the corner protrusions 11 facing the transverse side pieces 4 , the bottom piece 1 has a raised attachment edge 110 , which assures an exact right-angled placement of the transverse side pieces 4 in the folded-open state.
In order to urge the user to grasp the shipping container at the transverse side pieces 4 connected in this way in a positive manner with the bottom piece 1 , the carrying handles identified by the reference numeral 43 are integrally molded on the outside of the transverse side pieces 4 between the respective hinge receptacles 400 . Finally, the representation of the longitudinal side piece 2 in accordance with FIG. 4 shows the forming of snap-in pins 26 which, in the folded-open state of the longitudinal side pieces 2 , engage corresponding recesses 420 in the transverse side pieces 4 and assure a great sturdiness of the shipping container, such as shown in FIGS. 3 a and 6 .
Because the bottom piece 1 , of the above explained embodiment in accordance with FIG. 2 , has an edge running around the top, formed by the attachment strips 12 , 110 , it is also used as a catch basin for liquid possibly exiting the shipped material in the shipping chamber. With an appropriate dimensioning of the encircling edge it is possible, for example, to assure a capacity of 1 l of liquid or more inside the bottom piece 1 .
It is a substantial characteristic of the shipping container that all individual pieces, including their functional elements, in particular the hinge elements, can be molded integrally from a particle foam without the use of separate individual parts, which makes possible a shipping container which is true-to-type and cost effective, but is extremely sturdy. Here, all linkage heads used can have the shape of a truncated cone or universal ball joint, and all linkage recesses a shape matching this.
Finally, the bottom piece 1 also has outside recesses 110 a which are designed corresponding to the hinge connections between the transverse side pieces 4 and the cover pieces 6 a , 6 b , so that several shipping containers can be stacked on top of each other, secure against slipping, in the unfolded state, see FIG. 7 , as well as in the folded state, as shown in FIG. 8 .
A further possible embodiment of the shipping container is shown in FIGS. 9 to 11 , wherein like elements have the same reference numerals as in the previously represented and described embodiments and will not be separately explained in what follows, provided this is not necessary for understanding this invention.
The shipping container represented in its position of use in FIG. 11 has a bottom piece 1 represented in greater detail in FIG. 9 and is equipped, as in the previously described embodiments, with an upwardly projecting corner protrusion 11 in each corner area.
In the area used for the pivotable fastening of a transverse side piece 4 , a fastening strip 110 , which upwardly projects past or beyond the bottom piece 1 , is formed between the facing corner protrusions 11 and the hinge elements, identified by the reference numeral 15 , in the corner protrusions, which strip, at the two ends located opposite the two corner protrusions 11 , itself has corresponding hinge elements 15 a , which are integrally molded and which correspond in their configuration to those of the recesses 15 in the corner protrusions 11 . The respective insertion opening 15 b for a hinge element of the transverse side piece 16 to be received in it, and which is shown in FIG. 10 by reference numerals 440 , extends parallel with respect to the bottom area 10 of the bottom piece 1 and is identified by the reference numeral 15 b.
As shown in the overview in accordance with FIG. 11 , each transverse side piece 4 , which also has the carrying handles 43 for carrying the shipping container, is doubly held on both sides of each formed-on hinge strip 44 by appropriately projecting hinge elements 440 in the corresponding hinge receptacle 15 or 15 a of a corner projection 11 or fastening projection 110 and, in the folded-open position shown in FIG. 11 , cannot be removed out of the receiving position, even in case of large loads arranged inside the shipping container. Thus, it is possible also with this embodiment to ship large loads inside the shipping container without the danger of the hinge connection between the bottom piece 1 and the transverse side piece 4 being overwhelmed.
As shown in the embodiment in accordance with FIG. 11 , the recesses 22 a are cut into the longitudinal side pieces 2 , which are used as opening aids for the two cover pieces 6 a , 6 b.
A further functionality of the represented shipping container corresponds to the exemplary embodiment previously described in detail by FIGS. 1 a to 8 , so that it is possible to omit further functionality explanations to prevent repetitions.
It is understood that, in place of producing them from particle foam, each one of the previously explained embodiments of the shipping container in accordance with this invention can also be produced, for example, from molded parts made of a thermoplastic material, such as polypropylene or polyethylene, which have hollow chambers, are therefore especially light and at the same time thermally insulating. Such hollow-chambered molded parts can for example be produced in accordance with a blow-molding method, such as now known for producing panel parts for the automobile industry and the like. | A thermally insulating transportation box, including a base part, two longitudinal side parts, two transverse side parts and at least one top part, which parts bound a transportation space and are produced from a thermally insulating material. The longitudinal side parts and the transverse side parts are pivotably mounted on the base part about pivot axes which each run parallel to the base part, so that they can be folded open from a folded-together arrangement, which extends parallel to the base part, into an arrangement which is perpendicular to this and in which they bound the transportation space, and the transportation space can subsequently be closed by the at least one cover part. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to power transmission couplings, and particularly to couplings which utilize shear pins as a torque transmitting connection between coupling elements associated with the coupled shafts.
In certain applications of power transmission couplings connecting driving and driven shafts, such as in steel rolling mills and conveyors, the driven apparatus is likely to be jammed or stopped suddenly with a resulting overload which can damage the coupling and other elements in the power train. To prevent uncontrolled damage to the power train, the couplings are often provided with shear elements which form the weakest link in the drive train. These shear elements are designed to fail when a preselected overload is applied to the coupling so that sudden stoppage of the driven equipment or other causes of extreme shockloads will have the effect of breaking the shear element before failure of the coupling or damage to other elements in the drive train can occur.
The shear element is typically in the form of a replaceable pin. Examples of couplings employing shear pins are numerous in the prior art and include U.S. Pat. No. 1,978,209 issued Oct. 23, 1934, to Kuhns; U.S. Pat. No. 3,246,483 issued Apr. 19, 1966, to Schmitter; U.S. Pat. No. 3,855,818 issued Dec. 24, 1974, to Hochreuter; and British Patent No. 381,403 dated Oct. 6, 1932. The shear pins typically include a centrally located annular groove which defines the point of minimum cross section at which the pin should fail if it is subjected to pure shear loading.
In order to function as designed as to be subjected to shear loading only, the shear pin must fit without any clearance within the two coupling elements which it joins. Anything short of an interference fit will result in the application of bending stresses on the shear pin and this can lead to bending fatigue failures of the pins even when the overload has not been experienced.
However, it is very difficult to assemble a coupling with shear pins with an interference fit. As a result, the shear pins are typically assembled with some clearance and bending stresses necessarily result. Because of this, it has become accepted practice to replace the shear pins on a scheduled basis even though no failure has occurred but instead as a precaution against the possibility of fatigue failure. This results in unnecessary down-time for the equipment being driven.
Following failure of the shear pins it is often difficult to remove both ends from their respective bores in the couplings elements unless access can be gained from each end of the pins. Even if access is provided from each end, it is often difficult to replace an unbroken pin because the two coupling elements will typically have moved angularly a small amount thereby offsetting slightly the axes of the respective bores. To reduce such problem it has been common to utilize so-called stepped shear pins in which the diameter on one end of the pin is smaller than the diameter on the other end, and the diameters of the respective bores in which the pin ends fit are also of different sizes. This allows withdrawal of the smaller end through the larger diameter bore. Examples of the stepped shear pins are found in U.S. Pat. No. 3,855,818 and British Patent No. 381,403. The use of stepped shear pins increases the expense, however, because they are more difficult to machine than a pin of constant diameter, and they also require different sized bores or bushings therefore increasing the number of different parts required for the couplings.
By the present invention, I have provided a shear pin coupling which permits ease of assembly and replacement of the shear pins while at the same time providing a fit which approaches that of an interference fit thereby significantly reducing bending moments on the pin.
SUMMARY OF THE INVENTION
In accordance with my invention I provide a shear pin assembly for joining opposing coupling elements, which includes an elongated pin having circular cylindrical ends and a central annular groove, a split tapered bushing for each end of the pin, each split bushing having an inner surface adapted to engage the outer surface of one end of the pin and an outer surface tapered in a direction towards the annular groove of the pin, a pair of outer bushings each having a tapered central opening adapted to receive one of the split bushings, the outer bushings adapted to be fitted into bores in the coupling elements, and means for forcing each split tapered bushing into the respective outer bushing to cause the split bushing to rigidly engage the respective end of the shear pin.
My invention further resides in a shear pin coupling which utilizes a plurality of such shear pin assemblies for joining coupling halves.
It is a general object of the invention to provide a shear pin assembly which is easy to assemble and to replace.
It is another general object of the invention to provide a shear pin coupling in which the pin is rigidly fixed with a clearance approaching an interference fit within the two coupling elements which it joins.
It is a specific object of the invention to provide a shear pin coupling in which the ends of the pin are mounted in split bushings within coupling elements joined by the pin.
It is another specific object of the invention to provide a shear pin coupling which will fail in shear as a result of overloads on the power train in which the coupling is connected and which will not fail due to bending fatigue.
It is another specific object of the invention to provide a shear pin coupling in which the pin can be of constant diameter, except for a central annular groove.
It is still another specific object of the invention to provide a shear pin coupling in which the shear pin and its bushings are symmetrical about the gap between the coupling halves to thereby minimize the number of parts required.
The foregoing and other objects and advantages of the invention will appear from the detailed description which follows. In the description reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in elevation and partially in section of a coupling in accordance with the teachings of this invention;
FIG. 2 is an end view in elevation, with a portion broken away for illustration, of the shear pin assembly of FIG. 1 to an enlarged scale; and
FIG. 3 is a view in vertical section of the shear pin assembly taken in the plane of the line 3--3 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The coupling is shown incorporated in a gear type coupling although the invention is usable in other forms of flexible shaft coupling, including the type which employs a serpentine grid such as shown in the Schmitter U.S. Pat. No. 2,181,537. The coupling includes a pair of identical hubs 10 which include a series of external, crowned gear teeth 11. The hubs 10 are adapted to be attached to respective driving and driven shafts 12 and 13 by suitable keys 14. The series of external gear teeth 11 mate with corresponding series of internal gear teeth 15 formed on the interior of identical cylindrical sleeve members 16. One end of the sleeve members 16 mounts an annular plate 17 which holds an O-ring seal 18 against an outer diameter of the hubs 10. The other end of each of the sleeve members 16 is connected to a respective one of two coupling members 19 and 20 by means of bolts 21.
One coupling member 19 includes an axially projecting outer cylindrical portion 22 and the other coupling member 20 includes an axially extending radially inner cylindrical portion 23 which is spaced from the cylindrical portion 22 of the flange member 19. A pair of bushings 24 and 25 are press fitted into the outer cylindrical portion 22 and provide a journaled support upon portion 23 for the assembly of sleeve member, and coupling member attached to each of the two shafts. A keeper member 26 is bolted to the free end of the radially inner cylindrical member 23 and provides axial restraint for the two coupling halves upon the breaking of the shear elements to be described.
As thus far described the coupling does not differ from that which is known. The present invention relates to an improved assembly for joining together the radially extending flanges 27 and 28 of the two coupling members 19 and 20 which are spaced apart and confront each other.
The flanges 27 and 28 are each provided with a series of angularly spaced bores 30 which can be aligned with the corresponding bore 30 of the opposite flange. Typically, there will be several bores 30 in each flange and in the preferred embodiment the number is four. An outer tapered bushing 31 is press fitted in each of the bores 30 and the outer bushing 31 has the surface 32 of its central opening formed as a section of a circular cone tapering in a direction towards the gap between the flanges. An inner split tapered bushing 33 is received within the tapered inner surface 32 of the outer bushing 31 and it has an outer surface 34 formed as a section of a cone which is complementary to the inner surface 32 of the outer bushing 31. The inner bushing 33 has a central bore 35 which is adapted to receive and engage one end of an elongated circular cylindrical shear pin 36. The shear pin 36 is formed with a central annular groove 37. A circular loading plate 38 has a rim 39 which is adapted to seat against the wider, outer end of the inner split bushing 33. The loading plate 38 has a central opening which receives a loading bolt 40 which is threaded into an adjacent end of the shear pin 36.
It will be appreciated that in assembling the coupling, the shear pin assemblies can be loosely assembled and then the respective loading bolts 40 can be tightened to force the split inner bushings 33 towards the gap between the flanges 27 and 28 with the result that the central bores 35 of the split bushings 33 will tightly grasp the outer surfaces of the ends of the shear pins 36. Accordingly, rather than relying upon closely machined tolerances, the split bushings can be forced to seat about the body of the shear pins 36 to thereby hold the shear pins 36 rigid within the flanges 27 and 28 to a degree approaching an interference fit.
During operation of the coupling, all torque transmitted from the driving shaft 12 to the driven shaft 13 passes through the shear pins 36. Because the shear pins 36 are rigidly fixed, they will be subjected almost totally to shear forces rather than to bending moments. As a result, failure of the shear pin should occur only when the designed overload condition is present, and premature failure due to bending moment fatigue is prevented.
When a shear pin does fail due to an overload condition, the broken ends of the pin are easily removed by loosening the bolts 40 and removing the load plates 38. The inner split bushing 33 can then be pulled out by the insertion of bolts in threaded holes 41 provided in the wide end of the split bushings. The removal and replacement of unbroken pins is similarly easily accomplished because of the large opening through which the shear pins 36 can be removed once the split bushings 33 have been backed off.
The outer tapered surface 34 of the split bushing 33 is advantageously provided with several annular recesses 42. Such recesses 42 aid in controlling the required axial force necessary to insert the split bushing into the outer bushing 31. This is accomplished by reducing the surface area of contact between the inner and outer bushings and thereby reducing the overall force required to insert and tighten the split bushings.
Preferably, the outer bushing 31 is formed with a hardness which is greater than that of the inner split bushing 33, and the split bushing 33 has a greater hardness than that of the shear pin 36. This reduces the tendency of one part becoming embedded into another and aids in removal of the assembly. The axial lengths in contact with respect to the inner and outer bushings and shear pins are similarly selected to reduce the tendency of embedding and in each instance the harder material extends axially beyond the softer material. As an example, the shear pins may be formed of a steel having a hardness of less than 160 Brinell, the split bushing may be of steel having a hardness of 245-285 Brinell, and the outer bushing may be of a steel having a hardness of 340 Brinell.
The angle of taper between the inner and outer bushings is preferably selected to avoid tensile stress within the shear pin assembly. An angle of between 2°-5° with respect to the axis of the shear pin 36 (and thus the shear pin assembly) will provide a self-locking angle in which the axial component of force across the engaging surfaces 32 and 34 of the bushings 31 and 33 will be slight.
Although the invention has been described as incorporated within a coupling, a shear pin assembly in accordance with the invention may be used to join other elements of a drive train. For example, the shear pin assemblies could be used to join a chain sprocket to a flange on a shaft within a drive train and may in fact be used to join any two-flanged elements.
The shear pin assembly is symmetrical about the groove 37 thereby reducing the number of different parts required. Because a shear pin of constant diameter can be used, the shear pins are easier to manufacture and removal is possible from either direction, as compared with the stepped shear pins of the prior art. | A shear pin assembly in a shaft coupling is disclosed in which an elongated, circular cylindrical shear pin having a central groove is held at its ends in split, tapered bushings received in tapered outer bushings press-fitted into bores in flanges of the two coupling halves. A loading bolt is threaded in each end of the shear pin and a head of the bolt bears against a loading plate which in turn is seated against the split inner bushing to force the inner bushing into place to rigidly grip the ends of the shear pin. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a filter circuit utilizing a charge transfer device such as a bucket brigade device or a charge coupled device, and is directed more particularly to a non-recursive transversal filter.
2. Description of the Prior Art
In general, a prior art filter circuit using a bucket brigade device may be as shown in FIG. 1. In simplest terms, a bucket brigade device periodically stores an input analog or digital signal from an input terminal 1 in a capacitor C0, then passes the stored charge a step at a time from left to right through capacitors C1, C2, . . . . At each step, a new input signal value is stored in C0. Thus, a moving stream of stored charges are moved along the bucket brigade device.
Input terminal 1 applies a signal voltage V S to the base of a PNP transistor 2 whose collector is grounded and whose emitter is connected through a resistor 3 to a power supply terminal maintained at a supply voltage +V CC and also through the cathode terminal of a diode 5 to a hot side of capacitor C0. The other or cold side of capacitor C 0 is connected to a clock terminal 6. The hot side of capacitor C0 is also connected to the emitter of an NPN transistor Q1 whose collector is connected to the emitter of an NPN transistor Q2 of the next stage. Similarly, the collectors and emitters of NPN transistors Q2, Q3, . . . are connected together, and capacitors C1, C2, . . . are connected between the bases and collectors of the respective transistors Q1, Q2, . . . , respectively. The capacitance of capacitors C0, C1, C2, . . . are all equal to the same capacitance value C. The bases of odd numbered transistors Q1, Q3, . . . are connected through a clock terminal 7 to a clock driver 8. The bases of even numbered transistors Q2, Q4, . . . are connected through clock terminal 6 to clock driver 8, respectively.
Clock terminals 6 and 7 are supplied with clock signals φ1 and φ2 (FIGS. 2A and 2B respectively) which have potentials or levels V DC and V DC +V P , at a 50% duty cycle. Clock signals φ1 and φ2 are 180° out of phase. The voltage V P satisfies condition (1) with respect to supply voltage V CC at power supply terminal 4.
V.sub.CC >V.sub.DC +2V.sub.P ( 1)
Further, signal voltage V S at input terminal 1 satisfies condition (2).
V.sub.DC +V.sub.P ≦V.sub.s ≦V.sub.DC +2V.sub.P ( 2)
The voltage V DC applied to the bases of transistors Q1, Q2, Q3, . . . is insufficient to turn them on but the voltage V DC +V P is sufficient to bias them into their active regions.
As an initial condition, assume that all capacitors are charged to voltage V P and that signal voltage V S applied to input terminal 1 is a first DC value V S1 . Signal voltage V S1 is thus applied to the cathode of diode 5. At time t o (FIG. 2A), the clock signal φ1 changes to V DC +V P and clock signal 2 changes to V DC . The voltage V DC at the base of transistor Q1 cuts off this transmission. The voltage V DC +V P at the upper or cold side of capacitor C o produces a voltage of V DC +2V P (FIG. 2C) at the lower or hot side of capacitor C0. According to equation (2), this voltage at the hot side of capacitor C0 and at the anode of diode 5 exceeds the signal voltage V S1 at the cathode of diode 5. Thus the charge in capacitor C0 bleeds off through diode 5 until the voltage at the hot side of capacitor C0 equals the signal voltage V S1 . The charge remaining in capacitor C0 at this time is {V S1 -(V DC +V P )}C.
At time t 1 (FIG. 2A), clock signal φ 1 decreases to voltage V DC . The voltage at the hot side of capacitor C0 is changed to V S1 -V P (FIG. 2C). At the same time, clock signal φ 2 (FIG. 2B) is increased to voltage V DC +V P . This voltage, applied to the base of transistor Q1, biases transistor Q1 into its active region. The same voltage applied to the cold side of capacitor C1 produces a voltage V DC +2V P (FIG. 2D) at the hot side of capacitor C1. Transistor Q2 is cut off by clock signal φ1 at its base. An amount of charge is fed from capacitor C1 through the collector-emitter path of transistor Q1 to increase the voltage at the hot side of capacitor C0 to V DC +V P . This occurs due to the voltage V DC +V P at the base of transistor Q1. Since the voltage at the hot side of capacitor C0 changes from V S1 -V P to V DC +V P , the charge transferred from the hot side of capacitor C1 to the hot side of capacitor C0 is expressed by equation (3). ##EQU1##
Since a charge of V P ·C was initially stored in the capacitor C1, its final charge is given as follows: ##EQU2## That is, during the period t o to t 1 , a voltage is stored in capacitor C0 which is equal to V S1 -(V DC +V P ). This voltage is transferred to capacitor C1 during the period t 1 to t 2 so that the voltage on capacitor C0 returns to V DC +V P . Since transistor Q2 is OFF at this time, capacitors C2, C3, . . . are not affected.
Further, during period t 2 to t 3 , signal voltage V S may assume a value V S2 . Capacitor C0 is charged to V S2 -(V DC +V P ) while capacitor C1 is returned to V DC +V P by this voltage at the base of transistor Q2. By the process previously described, capacitor C2 is charged to V S1 -(V DC +V P ). Since the transistor Q3 is OFF, capacitors C3, . . . are not affected. The above operation is repeated and the signal is transferred from left to right on FIG. 1 in synchronism with clock signals φ1 and φ2.
When a transversal filter of, for example, a non-recursive type is formed using the above bucket brigade device, a plurality of intermediate taps are provided at appropriate points in the sequence. This has the effect of providing signals with different delay times which may be weighted in a predetermined way and added successively to produce an output signal.
The hot sides of capacitors C0, C2 and C4, from which signals are derived, are connected to the bases of emitter follower transistors 91, 92 and 93, respectively. The emitters of the transistors 91, 92 and 93 are connected to input terminals of differential amplifiers 94, 95 and 96, respectively. The other input terminals of differential amplifiers 94, 95 and 96 are connected to a constant voltage source represented by a battery. Outputs of differential amplifiers 94, 95 and 96 are commonly connected through an emitter follower transistor 98 to an output terminal 10.
The signals from the intermediate taps are delivered through emitter follower transistors 91, 92 and 93 and added in an analog manner in differential amplifiers 94, 95 and 96. The voltages may be weighted by adjusting the gains of the differential amplifiers to desired values.
Analog adding by differential amplifiers, as in the prior art, requires an excessive number of components with a resultant high power dissipation. Also, slight imbalance in the gain adjustment of the differential amplifiers may upset the balance of the circuit and produce scattering in the DC level. As a consequence, the correct relationships between input and output may not be achieved or the output DC level may become unstable.
Further, due to the presence of the collector-base capacitance C CB of emitter follower transistors 91, 92 and 93, the effective pulse height of the clocking signal is reduced by a factor of C/(C+C CB ) and the dynamic range of the signal is proportionately lowered. Also, the signal is affected by the base current of emitter follower transistors 91, 92 and 93. Therefore, a non-recursive transversal filter utilizing the circuit shown in FIG. 1 is not satisfactory.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a novel filter circuit utilizing a charge transfer device.
It is another object of the invention to provide a non-recursive transversal filter circuit utilizing a charge transfer device free of the defects of the prior art.
According to an aspect of the invention, there is provided a filter circuit comprising a charge transfer device, a clock signal drive circuit including means for supplying a clock signal to the charge transfer device, the charge transfer device including a plurality of successive capacitive storage means for sequentially holding a charge level representing a time sampled input signal, each of the capacitive storage means having a clocking electrode for receiving the clock signal so that the charge level is transferred from one to another of the capacitive storage means in succession in response to the clock signal, a predetermined plurality of the plurality of capacitive storage means being divided into first and second capacitive portions connected in parallel for the transfer and having a selected capacitive ratio, the first capacitive portions having the respective first mentioned clocking electrodes for receiving the clock signal and the second capacitive portions having respective second clocking electrodes, a first connection point connected to a predetermined number of the second clocking electrodes, a second connection point connected to the remaining number of the second clocking electrodes, the clock signal drive circuit further including first and second clock driver circuits operated in synchronism with the clock signal and connected to the first and second connection points, respectively, current detecting means for detecting currents flowing through the first and second clock driver circuits, respectively, and output means for compounding the detected currents and deriving an output signal.
The above, and other objects, features and advantages of the present invention, will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a filter circuit according to the prior art.
FIGS. 2A to 2D are waveforms to which reference will be made in explaining the operation of filter circuits in the prior art and the present invention; and
FIGS. 3 to 15 are schematic diagrams of filters according to a number of embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 3, a bucket brigade device according to the present invention includes a plurality of even numbered capacitors C0, C2, . . . which are divided into capacitors portions C0', C0"; C2', C2"; . . . The capacitances of the capacitor portions are a0C, (1-a0)C; a2C, (1-a2)C; . . . so that the sum of the pairs of corresponding portions is C. The cold sides of even numbered primed divided capacitors C0', C2', . . . are connected together, and the cold sides of even numbered double primed divided capacitors C0", C2", . . . are connected to clock terminal 6.
Complementary transistors 11 and 12 have their emitters connected together and to a common point of the cold sides of even numbered divided capacitors C0', C2', . . . and their bases connected together to the output side of a clock signal generator 13. Clock signal generator 13 delivers a clock signal φ1' which has the same phase as clock signal φ1 and provides voltages of V DC -V BE and V DC +V P +V BE (where V BE is the base-emitter voltage of transistors 11 and 12). The collector of PNP transistor 12 is grounded and the collector of NPN transistor 11 is connected to an output terminal 14.
With no input signal, the voltages at the hot sides of all of capacitors C0', C0", C2', C2", . . . are V P . During the first period from t o to t 1 when clock signal φ1 is at the level of V DC +V P (FIG. 2A), if a first input signal V S1 is applied to input terminal 1, the voltage across capacitor C0' is changed from V P to V S1 -(V DC +V P ). During this period, a charge of ##EQU3## is discharged through the collector of transistor 11. One clock period τ(τ=1/f c where f c is the clock frequency), later from τ 2 to τ 3 during the clock signal φ1, the capacitor C2' is discharged through transistor 11. At this time, the charge is expressed as follows: ##EQU4##
At the same time a second input signal V S2 may be accepted in capacitor portion C0'.
An additional clock period later from t 4 to t 5 of clock signal φ1, a charge expressed by the following equation (7) is discharged from capacitor C4' through the collector of transistor 11. ##EQU5##
Since all discharging charges from all of capacitor portions C0', C2', C4'. . . flow through the collector of transistor 11, the total charge Q OUT flowing through the collector of transistor 11 is expressed as follows: ##EQU6## where Z=e s τ, S=jw=j2πf and f is the frequency of the input signal.
A summed signal is thus derived at the collector of transistor 11 which corresponds to the successive samples of the input signal V S successively delayed by 0, τ, 2τ, . . . , weighted by a0, a2, a4, . . . and then added. Thus, with selected values of a0, a2, . . . , a filter having a predetermined transfer function is formed.
The average or mean value I AV of the collector current of transistor 11 is expressed as follows:
I.sub.AV =Q.sub.OUT /τ=Q.sub.OUT ·f.sub.c (9)
The embodiment of the invention in FIG. 3 produces an output in the form of a current I 0 . The embodiment of FIG. 4 produces a voltage output signal. The collector of transistor 11 is connected through the collector-emitter path of an NPN transistor 31 to power supply terminal 4 and the base of transistor 31 is connected to clock terminal 7. At the same time, a capacitor 32 with a capacitance of C A is connected at one terminal to the junction of the collector and emitter transistors 11 and 31 respectively and at the other terminal to clock terminal 6. An output terminal 33 is connected to the connection point between the collector of transistor 11 and the emitter of transistor 31. The initial charge on capacitor 32 is V P ·C A .
A charge Q OUT is transferred through transistor 11 as in the previous embodiment. The charge on capacitor 32 becomes V P ·C A -{(V DC +2V P )-V S } C(a0+a2Z -1 + . . . ) during the high periods (V DC +V P ) of clock signal φ1 and hence the potential of the signal voltage is added at input terminal 1. Thus, the output voltage V OUT is expressed as follows: ##EQU7##
If V S +V SDC +V SAC (where V SDC =the DC signal component and V SAC =the AC signal component), the voltage V OUT can be rewritten as follows: ##EQU8##
In the above formula, the first term is the AC signal term and all other terms are DC component terms. Since f=0 in the DC component terms, Z -1 =Z -2 =. . . =1. Therefore, the voltage V OUT is expressed as follows: ##EQU9##
That is, in the circuit shown in FIG. 4, an output signal of C/C A (a0+a2Z -1 + . . . )V SAC is produced in response to the AC signal component. At this time, the DC signal component in the output is as follows: ##EQU10## Thus, a DC level shift of ##EQU11## is produced.
Transistor 2 and diode 5 at the input side of the bucket brigade device, increases the DC potential by 2V BE . The DC potential may be reduced using a two-stage cascaded emitter follower circuit using transistors 34 and 35 to produce an output at alternate output terminal 33'. The emitter followers have the additional advantage of reducing the current required from the circuit to produce the output.
Alternatively, one end of capacitor 32 may be connected to clock signal generator 13 as indicated by the broken line rather than to clock terminal 6. When connected this way, the output voltage V OUT becomes as follows:
V.sub.OUT =V.sub.S1 +2V.sub.BE (13)
FIG. 5 shows an embodiment of a bucket brigade device in which the signal is passed beyond the input capacitor C0 before it is called upon to produce an output signal. Odd numbered capacitors C1, C3, . . . are divided into capacitor portions C1', C1"; C3', C3"; . . . whose capacitances are a1C, (1-a1)C; a3C, (1-a3)C; . . . The cold sides of the odd numbered primed capacitor portions C1', C3', . . . are connected together, and the cold sides of the odd numbered double primed capacitor portions C1", C3", . . . are connected to clock terminal 7.
Complementary transistors 15 and 16 have their emitters connected together to the connection point of the cold sides of divided capacitors C1', C3', . . . and their bases connected together to the output side of a clock signal generator 17. Clock signal generator 17 delivers a clock signal φ2' which has the same phase as the clock signal φ2 and which assumes voltages of V DC -V BE and V DC +V P +V BE (where V BE is the base-emitter voltage of transistor 15 and 16). The collector of NPN transistor 15 is connected to power supply terminal 4 and the collector of PNP transistor 16 is connected to an output terminal 18.
When no input signal voltage is supplied, the terminal voltages of all divided capacitor portions C1', C1", C3', C3", . . . are V P . Between t o and t 1 (FIG. 2A) of clock signal φ1 if a signal voltage S1 is applied to input terminal 1, capacitor C0 is charged up to a terminal voltage of V S1 -(V DC +V P ). During the period t 1 to t 2 clock signal φ2 enables a charge of a1C{(V DC +2 V P )-V S 1} to flow to capacitor portion C1' from transistor 15 in the direction of an arrow I1. During the period t 2 to t 3 , clock signal φ1 transfers the same charge through transistor 16 in the direction of an arrow I0.
During the period t 3 to t 4 , a charge of a3C{(V DC +2 V P )-V S1 } flows from capacitor C3' through transistor 16 in the direction of the arrow I0.
During the period t 4 to t 5 , a charge of a5C {(V DC +2 V P )-V S1 } flows from capacitor C5 through the collector of transistor 16.
The total amount of charge Q OUT , which flows through the collector of transistor 16 at this time, is expressed as follows: ##EQU12##
That is a signal current Io is derived from the collector of transistor 16 which corresponds to the successive samples of the input signal delayed by 0, τ, 2τ, . . . , weighted by a1, a3, a5, . . . and then added. Since the formula for the output signal is multiplied by Z -1 , the filter delays the most recent sample by τ before providing an output. However, since the characteristic of the filter is determined by the term (a1+a3Z -1 + . . . ), a filter having a characteristic similar to the one in FIG. 3 can be formed by proper adjustment of the values of the constants a1, a3, . . .
The average or mean value I AV of the collector current of transistor 16 is expressed as follows:
I.sub.AV =Q.sub.OUT /τ=Q.sub.OUT ·f.sub.c (15)
FIG. 6 is an embodiment of the invention otherwise similar to that shown on FIG. 5, except that the output is a voltage rather than a current. The collector of transistor 16 is grounded through the collector-emitter path of an NPN transistor 36 which, together with an NPN transistor 37, forms a current mirror circuit. The emitter of transistor 37 is grounded and its collector is connected to the emitter of transistor 31 and to capacitor 32. The base of transistor 31 is connected to the connection point of the emitters of transistors 15 and 16 at which a signal equivalent to clock signal φ2 is obtained. Output terminal 33 is connected to the connection point of transistors 31 and 37.
The base of transistor 31 receives a signal equivalent to clock signal φ2. Capacitor 32 is driven by clock signal φ1, and during the periods when clock signal φ1 assumes the voltage V DC +V P , transistors 16 and 37 are turned ON to discharge capacitor 32. Thus, an output voltage V OUT is produced in a manner similar to circuit of FIG. 4 as follows: ##EQU13##
Emitter followers 34 and 35 may be used to remove the DC offset as in the circuit of FIG. 4.
The base of transistor 31 may alternatively be connected to clocking signal generator 17 as shown by the broken line. In this case, the output voltage V OUT is expressed as follows:
V.sub.OUT =V.sub.S1 +V.sub.BE (17)
FIG. 7 shows an embodiment of a non-recursive transversal filter according to the present invention using the circuit of FIG. 4 including the broken line connection, but also including an arrangement for using both positive and negative factors or constants. Transistors 11p and 12p form a positive output circuit. The cold sides of selected capacitor portions C0', C4', . . . , whose factors a0, a4, . . . are positive, are connected together to the connection point between the emitters of transistors 11p and 12p. Transistors 11m and 12m form a negative output circuit. The cold sides of capacitors C2', C6', . . . , whose factors a2, a6, . . . are negative, are connected together to the connection point between the emitters of transistors 11m and 12.
The collector of transistor 11m is connected to the collector and base of a PNP transistor 42 which, together with a PNP transistor 44 forms a current mirror circuit 41. The emitters of transistors 42 and 44 are connected through resistors 43 and 45 respectively to power supply terminal 4. The bases of transistors 42 and 44 are connected together. Resistors 43 and 45 balance current mirror circuit 41 and generally are selected for equal resistance which may include zero. The collectors of transistors 11p and 44 are connected together to the emitter of transistor 31 and to capacitor 32.
When clock signal φ1 assumes the value of V DC +V p , a charge of
{(V.sub.DC +2 V.sub.p)-V.sub.S }C(a0+a4Z.sup.-2 + . . . )
flows from capacitor 32 through transistor 11p to capacitor portions C0', C4', . . . During the same periods, a charge of
{(V.sub.DC +2 V.sub.P)-V.sub.S }C(a2Z.sup.-1 +a6Z.sup.-3 + . . . )
flows through transistor 11m from capacitor portions C2', C6', . . . to current mirror circuit 41. A like charge from current mirror circuit 41 is added to capacitor 32.
The final charge Q A on capacitor 32 is expressed as follows: ##EQU14##
Thus, the output voltage V OUT is added to the potential of clock signal φ1 and hence is expressed as follows: ##EQU15##
If it is assumed in formula (19) that V S =V SDC +V SAC and Z -1 =Z -2 = . . . 1, the output voltage V OUT can be expressed as follows: ##EQU16##
In formula (20), the first term is the AC signal term and the second and following terms are the DC signal terms.
Thus, according to the present invention, a very simple non-recursive transversal filter can be provided having a transfer function H(z) of:
H(z)=C/C.sub.A (a0-a2Z.sup.-1 +a4Z.sup.-2 -a6Z.sup.-3 + . . . ) (21)
Further, since the capacitors are supplied with clock pulses during normal transfer times, the signal transferred through the bucket brigade device is not affected by the output circuit of FIG. 7.
If the capacitance value of capacitor 32 is taken as C A , which is expressed as follows:
C.sub.A =|(a0+a4+ . . . )-(a2+a6+ . . . )|C (22)
the third term of formula (20) becomes zero, and the DC level of the output becomes V SDC from which the DC level shift between the input and output is removed. The transfer function H(z) becomes as follows and the signal gain is lowered. ##EQU17##
If the capacitance value C A of capacitor 32 is taken as C(=C A ), the signal gain is maintained but the following DC level shift is generated.
(V.sub.DC +2 V.sub.P -V.sub.SDC){1-(a0-a2+a4-a6+ . . . )}
In order to remove the above DC level shift, a capacitor 46 may be connected between ground and connection point E1 of the emitters of transistors 11p and 12p or the connection point E2 of the emitters of transistors 11m 12m as shown in dashed line. The capacitance value C' of capacitor 46 may be selected as follows:
C'=k|1-(a0-a2+a4-a6+ . . . )|C (24)
In the formula (24), k is as follows:
k=(V.sub.DC +2 V.sub.P -V.sub.SDC)/V.sub.P (25)
which represents the ratio between the peak value V P of clock signals φ1 and φ2 and the difference between the peak value (V DC +2 V P ) at the hot side of the respective capacitor in the bucket brigade device and the DC component V SDC of the input signal V S . That is, when (a0-a2+a4-a6+ . . . )>1, a negative DC level shift is generated due to an excess of DC current discharged from capacitor 32. Thus, when this excess DC current is compensated by the presence of capacitor 46, the DC level shift is removed. The capacitance value C' of capacitor 46 may be selected as follows to accomplish this compensation:
C'=k{(a0-a2+a4-a6+ . . . )-1}C (26)
During the periods when clock signal φ1 assumes the value V DC +V P , the charge flows to capacitors C0', C2', . . . and an excess charge expressed by the following formula (27) flows through transistor 11m to capacitor 46. ##EQU18##
Thus, an excess charge of V P C' is supplied through current mirror circuit 41 to capacitor 32. The shift charge stored in capacitor 32 by the above DC level shift is expressed as follows: ##EQU19## This shift charge is cancelled by an excess charge supplied by current mirror circuit 41.
When (a0-a2+a4-a6+ . . . )<1, a positive DC level shift is caused by an excess charge on capacitor 32. This excess can be cancelled if capacitor 46 connected to point E1, has the following capacitance value C':
C'=k{1-(a0-a2+a4-a6+ . . . )}C (29)
During the periods in which clock signal φ1 assumes the value V DC +V P , a charge expressed by the following formula (30) flows to capacitor 46. ##EQU20## This charge compensates for the DC level shift as in the previous case.
FIG. 8 shows another embodiment of the invention in which a non-recursive transversal filter including positive and negative factors is formed using the circuit of FIG. 6.
Transistors 15p and 16p form a positive output circuit. The cold sides of capacitors C1', C5', . . . , whose factors (a1, a5, . . . ) are considered to be positive, are connected together to the connection point between the emitters of transistors 15p and 16p. Transistors 15m and 16m form a negative output circuit. The cold sides of capacitors C3', C7', . . . , whose factors (a3, a7, . . . ) are considered to be negative, are connected together to the connection point between the emitters of transistors 15m and 16m. The collector of a transistor 37m in the negative output circuit is connected to the collector and base of transistor 42 and to the base of PNP transistor 44 in current mirror circuit 41. The collector of a transistor 37p, in the positive output circuit, and the collector of transistor 44 of current mirror circuit 41 are connected together to the emitter of transistor 31 and to capacitor 32.
An output voltage V OUT is produced by the circuit of FIG. 8 as follows: ##EQU21##
Thus, a non-recursive transversal filter with a transfer function H(z) expressed by the following formula (32) is formed.
H(z)=C/C.sub.A (a1-a3A.sup.-1 +a5Z.sup.-2 -a7Z.sup.-3 + . . . ) (32)
In this filter, if the capacitance value C A of capacitor 32 is selected as expressed by the following formula (33), the DC level shift in the output voltage V OUT disappears.
C.sub.A =|(a1+a5+ . . . )-(a3+a7+ . . . )|C (33)
If C A =C, a DC level shift expressed by
(V.sub.DC +2 V.sub.P -V.sub.SDC) {1-(a1-a3+a5-a7+ . . . )}
is produced. In order to remove this DC level shift, when (a1-a3+a5-a7+ . . . )>1, a capacitor 46, shown in dashed lines, with a capacitance value C' expressed by the following formula (34) may be connected between ground and the connection point of the emitters of transistors 15m and 16m.
C'=k|1-(a1-a3+a5-a7+ . . . )|C (34)
When (a1-a3+a5-a7+ . . . )<1, a DC offset correction circuit, shown in dashed line, consisting of complementary transistors 47, 48 and capacitor 46 may be inserted between the emitter of transistor 31 and ground.
FIG. 9 shows a further embodiment of the invention in which positive factors are derived from a circuit according to FIG. 4 and negative factors are derived from a circuit according to FIG. 6.
The cold sides of capacitors C0', C4, . . . are connected together to the connection point of the emitters of transistors 11p and 12p, and the cold sides of capacitors C1', C5', . . . are connected together to the connection point of the emitters of transistors 15m and 16m. The collectors of transistors 11p and 44 are connected together to transistor 31 and capacitor 32.
The transfer function H(z) of the circuit of FIG. 9 is expressed as follows:
H(z)=C/C.sub.A (a0-a1Z.sup.-1 +a4Z.sup.-2 -a5Z.sup.-3 + . . . ) (35)
The capacitance value of C' of capacitors 46, shown in dashed lines, for removing the DC level shift, may be selected as follows:
C'=k|1-(a0-a1+a4-a5+ . . . )|C (36)
FIG. 10 shows a further embodiment of the invention in which two filtered outputs are derived from a single bucket brigade device using the circuits of FIGS. 7 and 8. The cold sides of capacitors C0', C4', . . . are connected together to transistors 11p and 12p, which form a first filter 51a, and the cold sides of the capacitors C2', C6', . . . are connected together to transistors 11m and 12m. Further, the cold sides of the capacitors C1', C5', . . . are connected together to transistors 15p and 16p, which form a second filter 51b, and the cold sides of capacitors C3', C7, . . . are connected together to transistors 15m and 16m. The transfer functions of the respective filters 51a and 51b are the same as those in the embodiments of FIGS. 7 and 8.
FIG. 11 shows a further embodiment of the invention which employs a differential amplifier in place of current mirror circuit 41 in the circuit of FIG. 7. Capacitors C0', C4', . . . are connected together to transistors 11p and 12p, and the collector of transistor 11p is connected to a transistor 31p and a capacitor 32p. The capacitance value C P of capacitor 32p is selected as follows:
C.sub.P =(a0+a4+ . . . )C (37)
Capacitors C2', C6', . . . are connected together to transistors 11m and 12m, and the collector of transistor 11m is connected to a transistor 31m and a capacitor 32m. The capacitance value Cm of capacitor 32m is selected as follows:
Cm=(a2+a6+ . . . )C (38)
A signal voltage V P , expressed by the following formula (39), is derived from the collector of transistor 11p.
V.sub.P =1/(a0+a4+ . . . ) (a0+a4Z.sup.-2 + . . . )V.sub.SAC +V.sub.SDC (39)
A signal voltage V m , expressed by the following formula (40), is derived from the collector of transistor 11m.
Vm=1/(a2+a6+ . . . ) (a2Z.sup.-1 +a6Z.sup.-3 + . . . )V.sub.SAC +V.sub.SDC (40)
These signals are supplied to a differential amplifier 60p, which consists of transistors 61p, 62p, 63p and a resistor 64p, and to a differential amplifier 60m, which consists of transistors 61m, 62m, 63m and a resistor 64m, respectively. A DC voltage source 65 equal to the DC component V SDC of the input signal is connected to the bases of transistors 63p and 63m. The collectors of transistors 63p and 62m are connected together through a resistor 66 to power supply terminal 4 and also to an output terminal 67.
If it is assumed that the resistance of resistor 64p is R p and that the resistance of resistor 66 is Ro, the gain of differential amplifier 60p is Ro/Rp. If it is assumed that the resistance of resistor 64m is Rm, the gain of differential amplifier 60m becomes Ro/Rm.
Thus, if resistance Rp and Rm are selected by the following formulas (41) and (42) respectively, the AC component V OAC of the output signal is expressed by formula (43). ##EQU22##
Further, a non-recursive transversal filter (not shown) can be also formed using the circuit of FIG. 8 with a differential amplifier in place of the current mirror circuit thereof.
FIGS. 12 and 13 respectively shows further embodiments of the invention in which a bucket brigade device including FETs (field effect transistors) is used. Capacitors C1, C2, . . . are connected between the drains and gates of respective FETs X1, X2, . . . The sources and drains thereof are successively connected together. The gates of every other FET X1, X2, . . . are connected together. The connection points of the gates of even FETs X2, X4, . . . are connected to clock terminal 6. The connection points of the gates of odd FETs X1, X3, . . . are connected to clock terminal 7. Capacitor C0 is connected between an input circuit A and clock terminal 6. In this bucket brigade device, the output circuit employs an enhancement mode MOS FET.
The output of the embodiment of FIG. 12 is derived from divided portions C0', C2', . . . of even capacitors C0, C2, . . . and hence this circuit corresponds to the circuit of FIG. 7. N-channel FETs 71p, 71m, 73, 76 and 77 are used in place of transistors 11p, 11m, 31, 34 and 35 of FIG. 7, and p-channel FETs 72p, 72m, 74 and 75 are used in place of transistors 12p, 12m, 42 and 44 of FIG. 7. FETs 71p, 72p and those 71m, 72m are complementary.
The output of the embodiment of FIG. 13, is derived from divided portions C1', C3', . . . of odd capacitors C1, C3, . . . , and hence this circuit corresponds to the circuit of FIG. 8. N-channel FETs 78p, 78m, 80p, 80m, 81p, 81m and 82 are used in place of transistors 15p, 15m, 37p, 37m, 38p, 38m and 47 of FIG. 8, and p-channel FETs 79p, 79m and 83 are used in place of transistors 16p, 16m and 48 of FIG. 8. The remainder of FIG. 13 is substantially the same as FIG. 12. FETs 78p, 79p; 78m, 79m; and 82 and 83 respectively, are complementary.
If the potential of clock signals φ1' and φ2' in the circuits of FIGS. 12 and 13 supplied to the gates of FETs 71p, 72p and 71m, 72m or 78p, 79p and 78m, 79m is set to V DC -V GS and V DC +V P +V GS , where V GS is the voltage drop across the gate-source of FETs 71p, 71m, 78p and 78m when they are conductive, and V GS ' is the voltage drop across the gate-source of FETs 72p, 72m, 79p and 79m when they are conductive, the circuits develop an output similar to the circuits in preceding embodiments.
FIGS. 14 and 15 respectively show still further embodiments of the invention using charge coupled devices (CCD). Electrodes K0, K1, . . . each having an area S are provided on the CCD and alternate electrodes are connected together. The connection point of even numbered electrodes K0, K2, . . . is connected to clock terminal 6 and the connection point of odd numbered electrodes K1, K3, . . . is connected to clock terminal 7.
In the embodiment of FIG. 14, an output is derived from even electrodes K0, K2, . . . which are respectively divided into electrodes K0', K0"; K2', K2"; . . . The areas of the electrodes are selected to be a0S, (1-a0)S; a2S, (1-a2)S; . . . One portion of each of divided electrode K0", K2", . . . is connected to clock terminal 6. Certain ones of the other portions of divided electrodes K0', K2', . . . are connected together to the output circuit consisting of FETs 71p and 71m to 77, etc., in a manner equivalent to the output circuit of FIG. 12.
In the embodiment of FIG. 15, an output is derived from odd electrodes K1, K3, . . . which are respectively divided into electrodes K1', K1"; K3', K3"; . . . in a manner similar to the embodiment of FIG. 14. One portion of each divided electrode K1", K3", . . . is connected to clock terminal 7. Certain ones of divided electrodes K1', K3', . . . are connected to the output circuit consisting of FETs 78p and 78m to 83, etc., in a manner equivalent to the output circuit of FIG. 13.
Stray capacitance exists between the electrodes supplied with clock signals φ1 and φ2 and the channel, and the charging and discharging of the stray capacitance depends upon the level of the incoming signal. Accordingly, by dividing the electrodes from which the output is derived in the above circuits, the capacitance can be divided in correspondence with the areas of the divided electrodes. If a separate clock signal is supplied to ones of the divided electrodes, the weighted outputs can be derived similar to the bucket brigade device. The outputs are then added and delivered as the output signal.
Further, since the operation of the filter of the invention is the same as the operation of a normal charge transfer device, the signal transferred through the bucket brigade device, or charge coupled device, or the CCD is unaffected.
Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A non-recursive transversal filter circuit employs a charge transfer device in which certain of the capacitive storage elements are divided into first and second capacitive portions having predetermined capacitance relationships. The charge in the second capacitive storage elements is sensed at predetermined times to produce an output signal. The relative capacitances of the second capacitance portions provide weighting factors to the filter. Embodiments include bucket brigade devices with bipolar and FET transistors as well as charge coupled devices. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved reinforcement structure for cavity walls, and, more particularly, to combined wall anchors and reinforcement trusses or ladders that utilize true-joints to fuse together the components under high heat and high pressure. The resultant anchoring systems meet high flatness requirements facilitating the formation of uniform mortar bed joints. This avoids stackup tolerances and reduces the cutting of blocks to fit within the height requirements. The flatness of the combined wall reinforcement and wall anchor enables the mason to more easily maintain the verticality of the wall.
2. Description of the Prior Art
Recently, special attention has been drawn to products that not only improve a mason's productivity, but also aid in straighter joint lines and ultimately better looking buildings. Among these products are cavity wall anchoring systems that tie together backup walls and facing veneers. While the backup walls or inner wythes may be masonry blocks, dry wall construction or poured concrete, this invention provides several examples of true jointed wall reinforcements and wall anchors for use with masonry black backup walls.
To date, numerous anchoring devices for insertion in bed joints of the backup walls have been marketed. In the main, each of these devices have a portion thereof or a separate interengaging component that is inserted in a corresponding bed joint of the facing veneer. Backup walls of masonry blocks also have a requirement that joint reinforcement be used. Standards in the construction industry have evolved to include a masonry joint reinforcement standard, namely, ASTM Standard Specification A 951-00 which describes joint reinforcement fabricated from cold drawn steel wire. As the production of better looking buildings requires uniformity in laying up the inner and the outer wythe, the competition for bed joint space between reinforcement materials and anchoring devices needs to be resolved in a manner satisfactory to the mason.
Over the past forty years there has been growing acceptance of wire formatives not only for wall reinforcements, but also for wall anchors and veneer anchors. It has become increasingly common to look toward a 0.375-inch high bed joint in both the inner wythe and the outer wythe. To maintain uniform joints, masons look toward mortar coverage above the reinforcement and wall anchor combination so that successive blocks are supported by the mortar layer and not by the wire formative. This enables the mason to adjust the placement of the block to maintain uniformity.
In the past, the use of wire formatives have been limited by the mortar layer thicknesses which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g. matching during renovations or additions the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire. On the other hand, contractors find that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. Thus, these contractors look towards substituting thinner gage wire formatives which result in easier alignment of courses of block.
In the past, there have been investigations relating to the effects of various forces, particularly lateral forces, upon brick veneer construction having wire formative anchors embedded in the mortar joint of anchored veneer walls. The seismic aspect of these investigations were referenced in the first-named inventor's prior patents, namely, U.S. Pat. Nos. 4,875,319 and 5,408,798. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces has resulted in the incorporation of a requirement for continuous wire reinforcement in the Uniform Building Code provisions. The first-named inventor's related Seismiclip R and DW-10-X R products (manufactured by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788) have become widely accepted in the industry. The use of a wire formative anchors in masonry veneer walls has also demonstrated protectiveness against problems arising from thermal expansion and contraction and has improved the uniformity of the distribution of lateral forces in a structure. However, these investigations do not address the mortar layer thickness vs. the wire diameter of the wire formative or technical problems arising therefrom.
In the course of preparing this disclosure several patents became known to the inventors hereof. The following patents are believed to be relevant and are discussed further as to the significance thereof:
Patent
Inventor
Issue Date
3,377,764
Storch
Apr. 16, 1968
4,021,990
Schwalberg
May 10, 1977
4,373,314
Allan
Feb. 15, 1983
4,473,984
Lopez
Oct. 02, 1984
4,869,038
Catani
Sep. 26, 1989
4,875,319
Hohmann
Oct. 24, 1989
5,392,581
Hatzinikolas et al.
Feb. 28, 1995
5,408,798
Hohmann
Apr. 25, 1995
5,454,200
Hohmann
Oct. 03, 1995
5,456,052
Anderson et al.
Oct. 10, 1995
5,816,008
Hohmann
Oct. 15, 1998
6,209,281
Rice
Apr. 03, 2001
6,279,283
Hohmann et al.
Aug. 28, 2001
It is noted that with some exceptions these devices are generally descriptive of wire-to-wire anchors and wall ties and have various cooperative functional relationships with straight wire runs embedded in the interior and/or exterior wythe. Several of the prior art items are of the pintle and eyelet/loop variety.
U.S. Pat. No. 3,377,764—D. Storch—Issued Apr. 16, 1968
Discloses a bent wire, tie-type anchor for embedment in a facing exterior wythe engaging with a loop attached to a straight wire run in a backup interior wythe.
U.S. Pat. No. 4,021,990—B. J. Schwalberg—Issued May 10, 1977
Discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet-metal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314—J. A. Allan—Issued Feb. 15, 1983
Discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to, avoid the insulation.
U.S. Pat. No. 4.473,984—Lopez—Issued Oct. 2, 1984
Discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,869,038—M. J. Catani—Issued 091/26/89
Discloses a veneer wall anchor system having in the interior wythe a truss-type anchor, similar to Hala et al. '226, supra, but with horizontal sheetmetal extensions. The extensions are interlocked with bent wire pintle-type wall ties that are embedded within the exterior wythe.
U.S. Pat. No. 4,879,319—R. Hohmann—Issued Oct. 24, 1989
Discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheet-metal anchor. Wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,392,581—Hatzinikolas et al.—Issued Feb. 28, 1995
Discloses a cavity-wall anchor having a conventional tie wire for mounting in the brick veneer and an L-shaped sheetmetal bracket for mounting vertically between side-by-side blocks and horizontally on atop a course of blocks. The bracket has a slit which is vertically disposed and protrudes into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 5,408,798—Hohmann—Issued Apr. 25, 1995 and U.S. Pat. No. 5,454,200—Issued Oct. 3, 1995
Discloses a seismic construction system for a cavity wall having a masonry anchor, a wall tie, and a facing anchor. Sealed eye wires extend into the cavity and wire wall ties are threaded therethrough with the open ends thereof embedded with a Hohmann '319 (see supra) clip in the mortar layer of the brick veneer. The Hohmann '200 patent is noted for the positive interengagement of the veneer anchor with the insertion end thereof sealed in the bed joint of the outer wythe.
U.S. Pat. No. 5,456,052—Anderson et al.—Issued Oct. 10, 1995
Discloses a two-part masonry brick tie, the first part being designed to be installed in the inner wythe and then, later when the brick veneer is erected to be interconnected by the second part. Both parts are constructed from sheetmetal and are arranged on substantially the same horizontal plane.
U.S. Pat. No. 5,816,008—Hohmann—Issued Oct. 15, 1998
Discloses a brick veneer anchor primarily for use with a cavity wall with a drywall inner wythe. The device combines an L-shaped plate for mounting on the metal stud of the drywall and extending into the cavity with a T-head bent stay. After interengagement with the L-shaped plate the free end of the bent stay is embedded in the corresponding bed joint of the veneer.
U.S. Pat. No. 6,209,281—Rice—Issued Apr. 3, 2001
Discloses a masonry anchor having a conventional tie wire for mounting in the brick veneer and sheetmetal bracket for mounting on the metal-stud-supported drywall. The bracket has a slit which is vertically disposed when the bracket is mounted on the metal stud and, in application, protrudes through the drywall into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 6,279,283—Hohmann et al.—Issued Aug. 28, 2601
Discloses a low-profile wall tie primarily for use in renovation construction where in order to match existing mortar height in the facing wythe a compressed wall tie is embedded in the bed joint of the brick veneer.
None of the above provide the masonry cavity wall construction system for an inner masonry wythe and an outer facing wythe with high-span anchoring wire formatives as described hereinbelow.
SUMMARY
In general terms, the invention disclosed hereby includes an anchoring system for a cavity wall. The embodiments described hereinbelow all utilize true-joint construction to reduce the height of wall reinforcement and wall anchor combinations, and thereby enable the erection of masonry block backup walls with highly uniform bed joint thicknesses and readily maintained verticality. Both the wall reinforcement and the wall anchor are wire formative elements and the elements, upon being joined, are fused together under heat and pressure. To accomplish this, the combined finished height of the assemblage of the wall reinforcement and wall anchor is limited to no greater than the diameter of wire used to form the wall anchor. By using the technique presented hereinbelow, ample mortar coverage is provided which, in turn, contributes to the accuracy of construction.
The embodiment of the invention disclosed hereby include a veneer anchoring system incorporating a swaged, double loop lock wall anchor in combination with a swaged, ladder-type wall reinforcement for use in the construction of a wall having an inner wythe with strips of insulation attached thereto. The seams between the strips of insulation are coplanar with the inner wythe bed joints. The compressively reduced in height wall anchors protrude into the cavity through the seams, which seams seal thereabout so as to maintain the integrity of the insulation and minimize air leakage along the wall anchors. In a second embodiment, wherein a truss-type wall reinforcement is used with a horizontal eye and pintle interengaging veneer anchor only the wall reinforcement is swaged. The invention contemplates that some components of the system are as described in U.S. Pat. Nos. 5,408,798; 5,454,200; and 6,279,283 and that the wire formatives hereof provide a positive interlocking connection therebetween specific for the requirements created by this true-joint application.
In the third embodiment of the invention, a box ladder-type wall reinforcement is used with a masonry block corner wythe. Here, the wall reinforcement has cross rods forming a T-head that extends into the cavity. The cross rods extend across the insulation into the cavity between the wythes. Each pair of cross rods is formed into a T-head to accommodate the threading thereinto of a wire formative veneer anchor of a bent box configuration inserted through the opening in the wall anchor. The veneer anchor is then positioned so that the insertion end is embedded in the facing wall. Wall anchors that are of limited height are described as being mounted in bed joints of the inner wythes. The close control of overall heights permits the mortar of the bed joints to flow over and about the wall reinforcement and wall anchor combination inserted in the inner wythe and insertion end of the veneer anchor in the outer wythe. The wire formatives hereof enable the anchoring system to meet the unusual requirements demanded.
OBJECTS AND FEATURES OF THE INVENTION
It is an object of the present invention to provide in a wall structure having a cavity formed by an outer wythe and an inner wythe, an anchoring system which employs true-joint wire formatives in the mortar joint of the inner wythe and is positively interconnected with a veneer tie inserted into the outer wythe.
It is another object of the present invention to provide labor-saving devices combining wall reinforcements and wall anchors to aid in the installation of inner wythe structures and providing for the securement thereto of facing veneers.
It is yet another object of the present invention to provide through utilizing true-joint techniques an anchoring system of low height and high flatness for wall reinforcement of the inner wythe.
It is a further object of the present invention to provide an anchoring system comprising a limited number of component parts that are economical of manufacture resulting in a relatively low unit cost.
It is yet another object of the present invention to provide an anchoring system which is easy to install and which meets seismic and shear resistance requirements.
It is a feature of the present invention that the flatness of the combined wall reinforcements and wall anchors facilitates obtaining uniform mortar layer thicknesses throughout the structure and improves the overall quality and trueness thereof.
It is another feature of the present invention that the veneer anchor and the combined wall tie reinforcement and wall anchor are dimensioned with a sufficiently low height so that, when inserted into the respective mortar layers, the mortar thereof can flow around the insertions end thereof to form a stronger wall structure.
It is yet another feature of the present invention that a true-joint is employed to combine the wall reinforcement and the wall anchor.
Other objects and features of the invention will become apparent upon review of the drawing and the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWING
In the following drawings, the same parts in the various views are afforded the same reference designators.
FIG. 1 is a perspective view of a first embodiment of an anchoring system for a cavity wall of this invention and shows a wall having an inner wythe of masonry block with insulation thereon and an outer wythe of brick;
FIG. 2 is a cross-sectional view of FIG. 1 showing the relationship among wall reinforcement thereof, the extended interlocking wall anchor, and, the box-type veneer anchor;
FIG. 3 is a partial perspective view from above of the wall reinforcement of FIG. 1 showing the swaged indentations thereof;
FIG. 4 is a partial perspective view from below of the, wall anchor of FIG. 1 showing the swaged indentations thereof corresponding to those of the wall reinforcement;
FIG. 5 is a perspective view of a second embodiment of a anchoring system for a cavity wall, similar to FIG. 1 , but employing a truss mesh reinforcement in the inner wythe, a horizontal eye wall anchor, and a rectangular pintle veneer anchor;
FIG. 6 is a partial perspective view of FIG. 5 showing a portion of the wall reinforcement, the wall anchor and the veneer anchor;
FIG. 7 is a partial perspective view of FIG. 6 showing the wall reinforcement of FIG. 5 and the swaged indentations thereof corresponding to the attachment sites of the wall anchor;
FIG. 8 is a partial perspective view of a third embodiment of an anchoring system for a cavity wall similar to FIG. 1 , but employing a T-head, ladder-box mesh combined wall reinforcement and wall anchor in the inner wythe and a bent-box anchor in the outer wythe; and,
FIG. 9 a partial perspective view of FIG. 8 showing a portion of the wall reinforcement, the wall anchor and the veneer anchor in relation to the cavity and the insulation therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before entering into the detailed Description of the Preferred Embodiments, several terms are while specifications may vary from one building to another, the bed joints are typically 0.375-inch (approx.) in height, defined, which terms will be revisited later, when some relevant analytical issues are discussed. For the purposes of this disclosure a true joint is defined as a juncture between two wire formatives wherein the elements are fusibly and interlockingly joined under heat and pressure. To improve the interlocking aspect of the joint one or both of the elements to be joined are cold-worked by swaging indentations therein which indentations receive a wire formative therewithin. The true joint of this invention also results in a juncture which is limited in height to be no greater than the diameter of the largest of the wire formatives.
Another term defined for purposes of this application is wall reinforcement. A wall reinforcement is a continuous length of Lox All® Truss Mesh or Lox All® Ladder Mesh manufactured by Hohmann & Barnard, Inc., Hauppauge, N.Y. 11788 or equivalent adapted for embedment into the horizontal mortar joints of masonry walls. The wall reinforcements are prefabricated from cold-drawn steel wire and have parallel side rods with butt welded cross rods or truss components. The wall reinforcements for true-joint anchoring systems are generally structured from 0.148- or 0.187-inch wire that complies with ASTM Specification A 951-00. The longitudinal wires of wall reinforcements are fabricated from steel, Type 304 SS, ASTM Specification A 580/A 580M, and are deformed to have a knurled surface therearound. When corrosion protection is specified, the wall reinforcement is provided with a mill or hot-dip galvanized finish, ASTM Specification A 641/A 641M or ASTM Specification A153/A 153M, respectively.
Referring now to FIGS. 1 through 4 , the first embodiment of a true-joint anchoring system for a cavity wall is now discussed in detail. For the first embodiment, a cavity wall having an insulative layer of 2 inches (approx.) and a total span of 3½inches (approx.) is chosen as exemplary. The anchoring system is referred to generally by the numeral 10 . A cavity wall structure 12 is shown having an inner wythe 14 of masonry blocks 16 and an outer wythe 18 of facing brick 20 . Between the inner wythe 14 and the outer wythe 18 , a cavity 22 is formed.
The cavity 22 is insulated with strips of insulation 23 attached to the exterior surface 24 of the inner wythe 14 and having seams 25 between adjacent strips 23 coplanar with adjacent bed joints 26 and 28 . Successive bed joints 26 and 28 are formed between courses of blocks 16 . The bed joints 26 and 28 are substantially planar and horizontally disposed and, while specifications may vary from one building to another, the bed joints are typically 0.375-inch (approx.) in height. Also, successive bed joints 30 and 32 are formed between courses of bricks 20 and the joints are substantially planar and horizontally disposed. Here again, while specifications may vary from one building to another, the bed joints are typically 0.375-inch (approx.) in height. Selected bed joint 26 and bed joint 30 are constructed to be interconnected utilizing the construct hereof.
For purposes of discussion, the cavity surface 24 of the inner wythe 14 contains a horizontal line or x-axis 34 and an intersecting vertical line or y-axis 36 . A horizontal line or z-axis 38 also passes through the coordinate origin formed by the intersecting x- and y-axes. A wall anchor 40 is shown which has an insulation-spanning portion 42 . Wall anchor 40 is a wire formative tie which is constructed for embedment in bed joint 26 and an interconnecting with veneer anchor 44 .
The masonry or wall anchor 40 is adapted from one shown and described in Hohmann, U.S. Pat. No. 5,454,200, which patent is incorporated herein by reference. The wall anchor 40 is shown in FIG. 1 as being emplaced on a course of blocks 16 in preparation for embedment in the mortar of bed joint 26 . In this embodiment, the system includes a ladder-type wall reinforcement 46 , a wall anchor 40 and a veneer anchor 44 . The wall reinforcement 46 is constructed of a wire formative with two parallel continuous straight, side wires 48 and 50 spaced so as, upon installation, to each be centered along the outer walls of the masonry blocks 16 . An intermediate wire body or a plurality of cross rods 52 are interposed therebetween and connect wire members 48 and 50 forming rung-like portions of the ladder-type reinforcement 46 .
At intervals along the ladder-type reinforcement 46 , spaced pairs of transverse wire members 54 are attached thereto and are attached to each other by a rear leg 56 therebetween. These pairs of wire members 54 extend into the cavity 22 . The spacing therebetween limits the x-axis movement of the construct. Each transverse wire member 54 has at the end opposite the attachment end, an eye wire portion 58 formed continuous therewith. Upon installation, the eye 60 of eye wire portion 58 is constructed to be within a substantially vertical plane normal to exterior surface 24 . The eye or veneer anchor receptor 60 is elongated vertically and accepts a veneer anchor threadedly therethrough. The anchor extends from eye 60 , across the cavity 22 , and into bed joint 30 . The eye 60 is slightly wider than the wire diameter of the veneer anchor. This dimensional relationship minimizes the z-axis movement of the construct. For positive engagement, the eye 60 of eye wire portion 58 is sealed to form a closed loop.
The veneer anchor or box tie 44 , FIGS. 1 and 2 , is, when viewed from a top or bottom elevation, generally rectangular in shape and is a basically planar body. The veneer anchor 44 is dimensioned to be accommodated by a pair of eye wire portions 58 described, supra. The veneer anchor 44 has a rear leg portion 62 , two parallel side leg portions 64 and 66 , which are contiguous and attached to the rear leg portion 62 at one end thereof, and two front leg portions 68 and 70 . To facilitate installation, the front leg portions 68 and 70 are spaced apart at least by the diameter of the eye wire member 58 . The longitudinal axes of leg portions 68 and 70 and the longitudinal axes of the contiguous portions of the side leg portions 64 and 66 are substantially coplanar. The side leg portions 64 and 66 are structured to function cooperatively with the spacing of transverse wire members 54 to limit the x-axis movement of the construct. The veneer anchor 44 is constructed so that with insertion through eye 60 , the misalignment tolerated is approximately one-half the vertical spacing between adjacent bed joints of the facing brick course. As will be described in more detail hereinbelow, the insertion portion 72 of veneer anchor 44 is considerably compressed with the vertical height being reduced. Upon compression, a pattern or corrugation 76 is impressed.
Referring now to FIGS. 3 and 4 details of the wall reinforcement and wall anchor of the above-described arrangement of wire formatives are shown. For the true joint, swaged into side wire 48 of wall reinforcement 46 are indentations 78 and 80 at attachment sites 82 and 84 , respectively; and into cross rod 52 , indentation 86 at attachment site 88 . In this embodiment, there are corresponding swaged indentations 90 and 92 in the pair of transverse wire members 54 at attachment sites 82 and 84 , respectively; and indentation 94 at attachment site 88 .
During assembly, the two components—the wall anchor 40 and the wall reinforcement 46 —are fusibly joined at attachment sites 82 , 84 and 88 under heat and pressure. Upon assembly, the true joints at the attachment sites 82 , 84 and 88 have a height no greater than the diameter of the wire of wall anchor 40 . Thus, for example, if the 0.187-inch diameter wire is employed for all components, upon insertion of the assemblage into bed joint 26 an equal height of mortar (as best seen in FIG. 2 ) would surround the wall reinforcement 46 and the insertion end of the wall anchor 40 . Similarly because of the flatness of the combined wall reinforcement and wall anchor assemblage, the ability to maintain verticality of the inner wythe is enhanced.
During the cold working of system components in addition to the swaged indentations, the insertion end of anchor 44 and the insulation-spanning portion 42 of wall anchor 40 are compressively reduced in height. As described in a prior patent of the present inventors, namely, Hohmann et al., U.S. Pat. No. 6,279,283, the insertion ends of the veneer anchor is, upon cold-forming, optionally impressed with a pattern on the mortar-contacting surfaces. For this application, while several patterns—corrugated, diamond and cellular—are discussed in the patent, only the corrugated pattern is employed. The ridges and valleys of the corrugations are shown in FIGS. 1 and 2 and are impressed so that, upon installation, the corrugations are parallel to the x-axis.
The cavity, as previously mentioned, has an insulation layer 23 which is shown in FIGS. 1 and 2 . The successive insulation strips 23 when in an abutting relationship the one with the other are sufficiently resilient to seal at seam 25 without air leakage therebetween. As the extended insulation-spanning portions 42 of wall anchor 40 are flattened, there is minimal interference with seal at seam 25 .
The description which follows is of a second embodiment of the true-joint anchoring systems of this invention. For ease of comprehension, where similar parts are used reference designators “100” units higher are employed. Thus, the veneer anchor 144 of the second embodiment is analogous to the veneer anchor 44 of the first embodiment. Referring now to FIGS. 5 through 7 , the second embodiment of an anchoring system of this invention is shown and is referred to generally by the numeral 110 . As in the first embodiment, a wall structure 112 is shown having an inner wythe 114 of masonry blocks 116 and an outer wythe 118 of facing brick 120 . Between the inner wythe 114 and the outer wythe 118 , a cavity 122 , is formed having an exterior surface 124 . Successive bed joints 126 and 128 are formed between courses of blocks 116 and the joints are substantially planar and horizontally disposed. Also, successive bed joints 130 and 132 are formed between courses of bricks 120 and the joints are substantially planar and horizontally disposed. Selected bed joint 126 and bed joint 130 are constructed to be interconnected utilizing the construct hereof. While specifications may vary from one building to another, the bed joints hereof are typically 0.375 inch (approx.) in height.
For purposes of discussion, the exterior surface 124 of the interior wythe 114 contains a horizontal line or x-axis 134 and an intersecting vertical line or y-axis 136 . A horizontal line or z-axis 138 normal to the xy-plane also passes through the coordinate origin formed by the intersecting x- and y-axes.
The wall anchor 140 is shown in FIG. 6 as having side wires 142 for interconnection with veneer anchor 144 and further is shown as being emplaced on a course of blocks 116 in preparation for embedment in the mortar of bed joint 126 . In this embodiment, a truss-type wall reinforcement 146 is constructed of a wire formative with two parallel continuous straight side wire members 148 and 150 spaced so as, upon installation, to each be centered along the outer walls of the masonry blocks 116 . An intermediate wire body 152 is interposed therebetween and connect wire members 148 and 150 separating and connecting side wires 148 and 150 of wall reinforcement 146 .
Referring now to FIGS. 5 , 6 and 7 , at intervals along the truss-type reinforcement 146 , spaced pairs of transverse wire members 154 are attached thereto and are attached to each other by a rear leg 156 therebetween. These pairs of wire members 154 extend into the cavity 122 . Each transverse wire member 154 has at the end opposite the attachment end an eye wire portion 158 formed continuous therewith. Upon installation, the eyes 160 of eye wire portion 158 are constructed to be within a substantially horizontal xz-plane normal to exterior surface 124 . The eyes 160 are horizontally aligned to accept the pintles of a veneer anchor 144 threaded therethrough. The eyes 160 are slightly larger than the diameter of the pintles, which dimensional relationship restricts the movement of the construct in the xz-plane. For ensuring engagement, the pintles of veneer anchor 144 are available in a variety of lengths to accommodate the misalignment, if any, of for example bed joint 126 with bed joint 130 .
The veneer anchor 144 is, when viewed from a top or bottom elevation, generally U-shaped. The veneer anchor 144 is dimensioned to be accommodated by a pair of eye wire portions 158 described, supra. The veneer anchor 144 has two rear leg portions or pintles 162 and 164 , two substantially parallel side leg portions 166 and 168 , which are substantially at right angles and attached to the rear leg portions 162 and 164 , respectively, and a front leg portion 170 . An insertion portion 172 of veneer tie 144 , which is considerably compressed upon installation extends beyond the cavity 122 into bed joint 130 . Insertion portion 172 includes front leg portion 170 and part of side leg portions 166 and 168 upon compression, a pattern or corrugation 176 is impressed. The longitudinal axes of side leg portions 166 and 168 and the longitudinal axis of the front leg portion 170 are substantially coplanar.
The insertion portion 172 of veneer tie 144 is considerably compressed and, while maintaining the same mass of material per linear unit as the adjacent wire formative, the vertical height 174 is reduced. The vertical height 174 of insertion portion 172 is reduced so that, upon installation, mortar of bed joint 130 flows around the insertion portion 172 . Upon compression, a pattern or corrugation 176 is impressed on either or both of the upper and lower surfaces of insertion portion 172 . When the mortar of bed joint 130 flows around the insertion portion, the mortar flows into the valleys of the corrugations 176 . The corrugations enhance the mounting strength of the veneer tie 144 and resist force vectors along the z-axis 138 . With wall tie 144 compressed as described, the wall tie is characterized by maintaining substantially all the tensile strength as prior to compression.
In the second embodiment, and referring now to FIGS. 6 and 7 , the details of the wall reinforcement 146 and wall anchor 140 of the above-described arrangement of wire formatives are shown. For the true joint, swaged into side wire 148 of wall reinforcement 146 are indentations 178 and 180 at attachment sites 182 and 184 , respectively; and into intermediate wire body indentations 186 at attachment sites 188 and 189 .
During assembly, the two components—the wall anchor 140 and the wall reinforcement 146 —are fusibly joined at attachment sites 182 , 184 and 188 and 189 under heat and pressure. Upon assembly, the true joints at the attachment sites 182 , 184 , 188 and 189 have a height no greater than the diameter of the wire of wall anchor 140 . Thus, for example, if the 0.187-inch diameter wire is employed for all components, upon insertion of the assemblage into bed joint 126 an equal height of mortar would surround the wall reinforcement 146 and the insertion end of the wall anchor 140 . As in the first embodiment, because of the flatness of the combined wall reinforcement and wall anchor assemblage, the ability to maintain verticality of the inner wythe is enhanced.
During the cold working of system components in addition to the swaged indentations, the insertion end of anchor 144 is compressively reduced in height. As described in a prior patent of the present inventors, namely, Hohmann et al., U.S. Pat. No. 6,279,283, the insertion ends of the veneer anchor is, upon cold-forming, optionally impressed with a pattern on the mortar-contacting surfaces. For this application, while several patterns—corrugated, diamond and cellular—are discussed in the patent, only the corrugated pattern is employed. The ridges and valleys of the corrugations are shown in FIGS. 5 and 6 and are impressed so that, upon installation, the corrugations are parallel to the x-axis 134 .
The description which follows is of a third embodiment of the high-span anchoring system of this invention. For ease of comprehension, where similar parts are used reference designators “200”units higher are employed. Thus, the wall anchor 240 of the third embodiment is analogous to the wall anchor 40 of the first embodiment. The veneer anchor of this embodiment is adapted from that shown in U.S. Pat. No. 5,454,200 to R. P. Hohmann; and the T-head, from that shown in U.S. Pat. No. 5,816,008 to R. P. Hohmann.
Referring now to FIGS. 8 and 9 , the third embodiment of a true-joint anchoring system of this invention is shown and is referred to generally by the numeral 210 . In this embodiment, a wall structure 212 is shown having an inner wythe 214 of masonry blocks 216 and an outer wythe 218 of facing stone 220 . Between the inner wythe 214 and the outer wythe 218 , a cavity 222 is formed, which cavity 222 has an exterior surface 224 . In the third embodiment, successive bed joints 226 and 228 are formed between courses of blocks 216 and the joints are substantially planar and horizontally disposed. Also, successive bed joints 230 and 232 are formed between courses of facing stone 220 and the joints are substantially planar and horizontally disposed. For each structure, the bed joints 226 , 228 , 230 and 232 are specified as to the height or thickness of the mortar layer and such thickness specification is rigorously adhered to so as to provide the uniformity inherent in quality construction. Selected bed joint 226 and bed joint 230 are constructed to align, that is to be substantially coplanar, the one with the other.
For purposes of discussion, the exterior surface 224 of the inner wythe 214 contains a horizontal line or x-axis 234 and an intersecting vertical line or y-axis 236 . A horizontal line or z-axis 238 normal to the xy-plane also passes through the coordinate origin formed by the intersecting x- and y-axes. In the discussion which follows, it will be seen that the various anchor structures are constructed to restrict movement interfacially—wythe vs. wythe—along the z-axis and, in this embodiment, along the x-axis. The system 210 includes a masonry wall anchor 240 constructed for embedment in bed joint 226 , which, in turn, includes a cavity-spanning or extension portion 242 . Further, the system 210 includes a wire formative anchor member 244 for embedment in bed joint 230 .
The components of the anchoring system 210 are shown in FIG. 8 as being emplaced on a course of blocks 216 and facing stone 220 in preparation for embedment in the mortar of bed joints 226 and 230 , respectively. In the best mode of practicing the invention, a combined box ladder-type wall reinforcement and wall anchor assembly 246 is constructed of a wire formative with two parallel continuous straight wire members 248 and 250 spaced so as, upon installation, to each be centered along the outer walls of the masonry blocks 216 . The structure further includes intermediate wire bodies or cross rod portions 252 of wall anchor 240 interposed therebetween and connecting wire members 248 and 250 . These cross rod portions 252 form rung-like elements of the reinforcement structure 246 . The cross rod portions 252 at intervals along the wall reinforcement 246 extend across wire members 248 and provide spaced pairs of transverse wire member portions 254 . The other end of cross rod portions 252 are electric resistance welded to wire reinforcement 250 . The pairs of wire members 254 are contiguous with extension portions 242 and extend across the cavity 222 to veneer anchor 244 . As will become clear by the description which follows, the spacing between the transverse wire member 254 is constructed to limit the x-axis movement of the construct. Each pair of transverse wire members 254 has at the end opposite the attachment end a T-head portion 258 formed contiguous therewith.
Upon installation, the receptors 260 of T-head portion 258 is constructed to be within a substantially horizontal xz-plane normal to exterior surface 224 . The receptor 260 is dimensioned to accept the tongue or bent portion of veneer anchor 244 and is slightly larger than the width of the tongue portion. This relationship minimizes the movement of the construct in an xz-plane.
The veneer anchor 244 is generally a bent box configuration and is dimensioned to be accommodated by the T-head receptor 260 of wall anchor 240 previously described. The veneer, anchor 244 has a tongue portion 262 with two parallel side leg portions 264 and connecting leg 266 , and two cavity-spanning leg portions 268 contiguous therewith. The leg portions continue to an insertion portion and the insertion portion side legs 270 have been compressively reduced in height. The insertion portion is completed with front leg portions 271 and 273 which are spaced apart at least by the diameter of the veneer reinforcing wire member 275 . An insertion portion 272 of veneer anchor 244 , upon installation, extends beyond cavity 222 into bed joint 230 , which insertion portion includes front leg portions 271 and 273 and side leg portions 270 adjacent to front leg portions 271 and 273 , respectively. The longitudinal axes of leg portions 268 , 270 , 271 , and 273 are substantially coplanar. The side leg portions 264 and connecting leg 266 are structured to function cooperatively with the spacing of the T-head 258 adjoining transverse wire members 254 to limit movement of the construct in the xz-plane.
The insertion portion 272 is considerably compressed and, while maintaining the same mass of material per linear unit as the adjacent wire formative, the vertical height 274 is reduced. The vertical height 274 of insertion portion 272 is reduced so that, upon installation, mortar of bed joint 230 flows around the insertion portion 272 . Upon compression, a pattern or corrugation 276 is impressed on insertion portion 272 and, upon the mortar of bed joint 230 flowing around the insertion portion, the mortar flows into the corrugations 276 . For enhanced holding, the corrugations 276 are, upon installation, substantially parallel to x-axis 234 . In this embodiment, an indentation 278 is swaged into leg portion 270 opposite the opening between front leg portions 271 and 273 , which indentation is dimensioned to accommodate veneer reinforcing wire 275 . With the insertion end 272 of veneer anchor 244 as described, the wall anchor is characterized by maintaining substantially all the tensile strength as prior to compression while acquiring a desired low profile.
Referring now to FIG. 9 details of the combined wall reinforcement and wall anchor assembly 246 of the above-described arrangement of wire formatives are shown. For the true joint, swaged into the cross rod portions 252 of wall anchor 240 are indentations 280 and 282 at attachment sites 284 and 286 , respectively. During assembly, the two components—the wall anchor 240 and the wall reinforcement 246 —are fusibly joined at attachment sites 284 and 286 under heat and pressure. Upon assembly, the true joints at the attachment sites 284 and 286 have a height no greater than the diameter of the wire of wall anchor 240 . Thus, for example, if the 0.187-inch diameter wire is employed for all components, upon insertion of the assemblage into bed joint 226 an equal height of mortar would surround the wall reinforcement 246 and the insertion end of the wall anchor 240 . Similarly because of the flatness of the combined wall reinforcement and wall anchorf assemblage, the ability to maintain verticality of the inner wythe is enhanced.
During the cold working of system components in addition to the swaged indentations, the insertion end of anchor 244 is compressively reduced in height. As described in a prior patent of the present inventors, namely, Hohmann et al., U.S. Pat. No. 6,279,283, the insertion ends of the veneer anchor is, upon cold-forming, optionally impressed with a pattern on the mortar-contacting surfaces. For this application, while several patterns—corrugated, diamond and cellular—are discussed in the patent, only the corrugated pattern is employed. The ridges and valleys of the corrugations are shown in FIGS. 8 and 9 and are impressed so that, upon installation, the corrugations are parallel to the x-axis.
Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. | A high-span anchoring system is described for a cavity wall incorporating a wall reinforcement combined with a wall tie which together serve a wall construct having a larger-than-normal cavity. Further the various embodiments combine wire formatives which are compressively reduced in height by the cold-working thereof. Among the embodiments is a veneer anchoring system with a low-profile wall tie for use in a heavily insulated wall. The compressively reduced in height wall anchors protrude into the cavity through the seams, between insulation strips, which seams seal thereabout and maintain the integrity of the insulation by minimizing air leakage. Further, the eye wires extend across the insulation into the cavity between the wythes, and each accommodates the threading thereinto of a wire facing anchor or wall tie with either a pintle inserted through the eye or the open end of the veneer tie. The veneer tie is then positioned so that the insertion end is embedded in the facing wall. The close control of overall heights permits the mortar of the bed joints to flow over and about the wall reinforcement and wall tie combination inserted in the inner wythe and insertion end of the wall in the outer wythe. Because the wire formatives hereof employ extra strong material and benefit from the cold-working of the metal alloys, the high-span anchoring system meets the unusual requirements demanded thereof. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to the U.S. provisional patent application serial No. 60/305,790 entitled “French Door Chiller Compartment for Refrigerators” filed on Jul. 16, 2001.
BACKGROUND OF THE INVENTION
The present invention relates generally to refrigerators and, more particularly, to a French door chiller compartment for refrigerators, wherein the chiller compartment is maintained at a temperature slightly lower than the rest of the interior of the refrigerator.
A refrigerator is often provided with a chiller compartment to keep beverages or food items at a slightly lower temperature than the rest of the interior. Quick and easy access to the items stored in the chiller compartment is desirable and therefore it would be preferable to mount the chiller compartment in the refrigerator door.
One disadvantage of current chiller compartments is that the doors, which separate the chiller compartment from the rest of the interior of the refrigerator, function independently of each other, requiring the user to employ both hands when gaining access to the chiller compartment to load or retrieve items. For example, U.S. Pat. No. 4,361,368 to Daniels discloses a refrigerator storage compartment that utilizes two sliding doors that work independently of each other. To gain access to the storage compartment, the user must slide each door individually. Further, sliding one of the doors only permits access to half of the storage compartment at one time. Similarly, U.S. Pat. No. 3,804,482 to Smith discloses a wine chiller with two doors that swing away from the cabinet. These cabinet doors function independently of each other, and the user would have to employ both hands to simultaneously open the doors in gaining quick access to all of the contents inside.
Another disadvantage of many chiller compartments is that the door or doors protrude from the chiller compartment while in the open position and may be damaged should the refrigerator door be closed while the chiller compartment door or doors are left open. U.S. Pat. No. 3,203,199 to Stewart discloses a compartment located in the bottom of the interior of the refrigerator with two doors that swing outward. While in the open position, the compartment doors protrude significantly from the interior of the refrigerator and may be damaged should the refrigerator door be shut while these compartment doors are in the open position. It is therefore desirable to have a chiller compartment with doors that will not break should the refrigerator door be closed while the compartment doors are open.
Additionally, the door or doors of many chiller compartments may not stay open on their own. These doors may require additional stops or latching devices to stay open, again requiring the user to employ both hands when gaining access to the chiller compartment to load or retrieve items. U.S. Pat. No. 5,100,213 to Vandarakis et al. discloses a refrigerator door chiller compartment with a door that slides open vertically. To keep the door open on its own, the user must slide the door to the fully open position, where a stop or latching device is used to keep the door open. However, the door will close if not manually restrained by the user. It is therefore desirable to have a chiller compartment which includes doors that will remain in position without additional securing devices.
Accordingly, a general feature of the present invention is the provision of a chiller compartment which overcomes the problems found in the prior art.
A further feature of the present invention is the provision of a chiller compartment for refrigerators including doors that allow for one-hand operation.
Another feature of the present invention is the provision of a chiller compartment for refrigerators with doors that will not become damaged if left in the open position while the refrigerator door is closed.
A still further feature of the present invention is the provision of a chiller compartment for refrigerators with doors that remain in the fully open, fully closed, or any intermediate position on their own without the need for additional stops or latching devices.
Another feature of the present invention is the provision of a chiller compartment for refrigerators with doors that open to provide full accessibility to the interior of the chiller compartment.
A further feature of the present invention is the provision of a chiller compartment for refrigerators capable of holding and retaining tall containers during normal opening and closing of the refrigerator door.
These, as well as other features and advantages of the present invention will become apparent from the following specification and claims.
SUMMARY OF THE INVENTION
The present invention is directed towards a refrigerator chiller compartment which generally includes a cabinet housing that secures to the inside of a refrigerator door. The cabinet housing has an open front side that allows for full access into the interior of the cabinet housing.
Two doors secured to the cabinet housing are connected to each other by a linkage that allows for simultaneous operation. By grasping and moving either door with one hand, the linkage engages to simultaneously move the other door. An internal tray is also provided. The internal tray has sides sufficiently tall to prevent tall beverages, such as 2-liter bottles or food items rolling or from toppling out should the refrigerator door be quickly opened or closed. Additionally, a top cover to the housing cabinet is provided for enclosing and protecting the door linkage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary side-by-side refrigerator with the door open to show a possible mounting arrangement for the chiller compartment of the present invention.
FIG. 2 is a perspective view of the French door chiller compartment of the present invention with the doors in the closed position.
FIG. 3 is an exploded view of the French door chiller compartment.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described as it applies to its preferred embodiment. It is not intended that the present invention be limited to the preferred embodiment. It is intended that the invention cover all modifications and alternatives that may be included within the spirit and scope of the invention.
With reference to FIG. 1, a refrigerator 10 is depicted and is of the style generally referred to as a side-by-side refrigerator, although the present invention also can be used with other types of refrigerators or freezers. The refrigerator 10 has an interior 12 accessed by a refrigerator door 14 , which is illustrated in the open position in FIG. 1 . The refrigerator 10 is provided with a chiller compartment 16 secured to the door 14 . Chiller compartment 16 of refrigerator 10 is provided with chiller compartment doors 18 .
In a conventional manner, cold air from the evaporator (not shown) is directed through a duct (not shown) in the refrigerator wall or mullion 22 that separates the refrigerator from the freezer 36 . The air is directed from an inlet port (not shown) in the mullion 22 to the chiller compartment 16 . This cold air maintains the chiller compartment 16 at a temperature slightly below the rest of the interior 12 of the refrigerator 10 . Preferably, the temperature of the chiller compartment 16 is adjustable through conventional means.
With reference to FIG. 2, the chiller compartment 16 is shown to generally comprise a cabinet housing 24 with doors 18 , shown in the closed position. Ports 38 in the cabinet housing 24 are adapted to allow for cold air from the inlet port (not shown) in the mullion 22 to enter the chiller compartment 16 . Including a plurality of ports 38 allows the chiller compartment 16 to be placed in a variety of positions in the refrigerator door 14 and yet be connected to the inlet port which may be in a fixed position. The cabinet housing 24 also includes one or more brackets 26 to quickly and easily secure the chiller compartment 16 to corresponding receiving brackets in the refrigerator door 14 . Each bracket 26 is a protrusion from the side of the cabinet housing 24 and may include any type of hook or latch.
With reference to FIG. 3, the chiller compartment 16 is shown to generally comprise a pair of vertically upstanding doors 18 A, 18 B, a chiller compartment cabinet housing 24 , a tray 34 , a chiller door linkage 28 , 30 and a chiller cabinet housing top cover 32 . The chiller compartment 16 may be of any desired height or width and the refrigerator 10 may include a variety of different sized chiller compartments 16 . Doors 18 A, 18 B may be generally referred to as French doors.
The cabinet housing 24 has a floor 40 , a top 42 including a front flange 44 , two vertically upstanding side walls 46 , 48 , and a back wall 50 . The top 42 is provided with suitable openings 52 , and the cabinet housing floor may be provided with openings 54 as will be hereinafter described in greater detail. The rear portion of side walls 46 , 48 of cabinet housing 24 may be provided with one or more brackets 26 to secure the chiller compartment 16 to the refrigerator door 14 . As is known in the art, all of the foregoing components of the chiller compartment 16 may be formed of any suitable material having the requisite strength and temperature resistance characteristics to be used in a refrigerator in a manner hereinafter to be described.
Chiller tray 34 has a vertically upstanding front wall 56 and a rear wall 58 . The front wall 56 has a height sufficient to retain the intended contents of the chiller compartment 16 , such as a plurality of bottles and other types of containers, within the chiller compartment 16 as the refrigerator door 14 is opened and closed, even if doors 18 A, 18 B have been left open. The bottom of chiller tray 34 is provided with support rings (not shown) which cooperate with doors 18 A, 18 B as will hereinafter be described. The front and rear walls 56 , 58 of chiller tray 34 are provided with one or more downwardly depending hooks or tabs 60 which are matingly received in the openings 54 in the floor 40 of the cabinet housing 24 . In this manner, the chiller tray 34 hooks and snaps into the cabinet housing floor 40 . Preferably, when the chiller tray 34 is snapped into the cabinet housing floor 40 , the bottom surface of chiller tray 34 is spaced from the cabinet housing floor 40 , as will hereinafter be described in further detail.
French doors 18 A, 18 B are each provided with a boss member 62 disposed on the top of upper flange members 64 A, 64 B of doors 18 A, 18 B. Similarly, each door 18 A, 18 B is provided with a lower flange member (not shown) with the front wall surfaces 66 A, 66 B of doors 18 A, 18 B extending between the upper and lower flange members of the doors 18 A, 18 B.
Boss members 62 of doors 18 A, 18 B are received within openings 52 in the top 42 of the cabinet housing 24 . The lower flange members of doors 18 A, 18 B are secured in place by chiller tray 34 , and the doors pivot about the support rings (not shown) disposed on the bottom of the chiller tray 34 . The rings also act as supports for the chiller tray 34 .
After boss members 62 of doors 18 A, 18 B are inserted through openings 52 , the door linkage 28 , 30 is assembled. Linkage members 28 are snapped into boss members 62 through openings 52 , and are connected by a center link 30 , the ends of which snap into linkage members 28 . Accordingly, upon movement of either of doors 18 A, 18 B in a pivoting, rotatable manner about boss members 62 , the pivoting, or rotating, motion of one door will cause the other door to pivot or rotate in the opposite direction via the door linkage 28 , 30 .
A top cover 32 may be provided and is snapped into the front flange 44 of cabinet housing 24 as by snap protrusions 74 . The French door arrangement of the doors 18 A, 18 B within the cabinet housing 24 allows a majority of the doors 18 A, 18 B, when open, to remain within the cabinet housing 24 . This minimizes any protrusion of the open doors 18 A, 18 B away from the refrigerator door 14 . This prevents a user from damaging the refrigerator 10 , the chiller compartment 16 , or the refrigerator contents should the refrigerator door 14 be closed with doors 18 A, 18 B left open. The widths of the front wall surfaces 66 A, 66 B of doors 18 A, 18 B are different, whereby when doors 18 A, 18 B are in a closed position, the point at which the right most vertical edge 68 of door 18 A meets with the leftmost edge 70 of door 18 B will be offset from the center line 72 of the cabinet housing 24 . Such an offset allows the user to easily grasp the extended vertical edge 68 when the doors 18 A, 18 B are open. A handle or other ergonomic surface may be provided on the vertical edge 68 . The front wall surfaces 66 A, 66 B of doors 18 A, 18 B are generally planar in configuration. The side portion 74 A, 74 B of each door 18 A, 18 B is generally curved to mate with the generally curved configuration of the side walls 46 , 48 of the cabinet housing 24 .
A general description of the present invention as well as a preferred embodiment of the present invention has been set forth above. Those skilled in the art to which the present invention pertains will recognize and be able to practice additional variations in the chiller compartment described which fall within the teachings of this invention. Accordingly, all such modifications and additions are deemed to be within the scope of the present invention which is to be limited only by the claims appended hereto. | A chiller compartment is provided that secures to the inside of a refrigerator door. The chiller compartment includes a pair of French doors that are connected by a linkage that causes the doors to simultaneously open or close. The doors retract within the chiller compartment when opened, thereby protecting the doors should the refrigerator door be closed while the chiller compartment doors are left open. The chiller compartment also includes a tray of sufficient height to secure tall beverages or food items and prevent such items from toppling out of the chiller compartment while the refrigerator door is opened or closed. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. provisional patent application No. 61/189,649, filed Aug. 21, 2008, the content of which is incorporated herein in its entirety.
TECHNICAL FIELD
The subject matter disclosed herein relates to pillows. Particularly, the subject matter disclosed herein relates to variable-use tubular pillows having attachable and detachable ends and related methods.
BACKGROUND
Typically, a pillow is a fabric bag ticking stuffed with a suitable soft resilient material, such as fiberfill, down or foam. Generally, pillows are used for providing a soft cushion on which to place one's head while resting or sleeping, either in bed, which generally have a removable cover; or on furniture in which case the pillows typically have a permanent fabric cover. Pillows have also been used in variety of other specific ways. For example, a caretaker of an infant or small child may utilize a pillow to cushion child's head while he or she is held against the caretaker's arm. In another example, a person may place a pillow under his or her injured arm or leg for elevating the extremity for increased comfort. Pillows have been especially useful in this manner following trauma or surgery. In yet another example, nursing home patients with bedsores from constant pressure at the elbow, knee, or such regions may use a standard pillow to try to relieve discomfort on the affected area. Pillows may also be used as a comfort support for arthritic extremities.
The use of a standard pillow for the aforementioned reasons and other purposes has some limitations and disadvantages. For example, the standard pillow can shift during normal body movement, especially during sleep. In addition, for example, the standard pillow does not provide for a combined comfort for both a caregiver and infant or small child during feeding or cuddling.
To address the aforementioned limitations and disadvantages, some modifications have been made to pillows to enhance their utility for specific functions. Particularly, there are a number of pillows configured to provide and means for encircling a person's arm or leg. One disadvantage of some known pillows, among others, is the lack of continuous cushioning around the entirety of the user's arm. Another disadvantage of other pillows is the entire pillow must be laundered in a tubular configuration, which can require an extended time period for drying. Still other disadvantages are the cumbersome, uncomfortable techniques required to utilize some pillows, such as straps, elastic, and/or a sling around user's neck. Therefore, it is desired to provide pillows in multiple environments overcoming these disadvantages, as well as providing additional improvements over prior pillow designs.
SUMMARY
Tubular pillows having attachable and detachable ends and related methods are disclosed. According to an aspect, a tubular pillow in accordance with the subject matter disclosed herein may include a pillow body having first and second ends being opposed to one another and being attachable to and detachable from one another. The pillow body forms a tube shape having a central tunnel when the first and second ends are attached. Further, the pillow body may include a removable cover for covering the pillow body.
According to another aspect, a tubular pillow before attaching the first and second ends in accordance with the subject matter disclosed herein, may have a width of about 15 inches and a length of about 26 inches, or any other suitable dimensions.
According to yet another aspect, a tubular pillow body ticking in accordance with the subject matter disclosed herein may be formed of a substantially soft and resilient material, and is subsequently filled with pliable synthetic fiber filler, down, foam, or other suitable material.
According to another aspect, the ends of the pillow body may include hook-and-loop fasteners for attachment of the ends to one another and for detachment of the ends from one another. Alternatively, buttons may be attached to one end and holes formed in the opposing end of the pillow body such that the buttons and holes can be used to attach and detach the ends. By attaching the ends together, the pillow body may form the central tunnel for fitting to the arm or leg of a person.
According to another aspect, a tubular pillow in accordance with the subject matter disclosed herein, the removable cover may be formed of a substantially rectangular-shaped fabric piece with two opposed linear edges thereof connected together defining a tunnel for receiving the pillow body inside the removable cover. Further, the removable cover may be formed of a washable material such as cotton and/or polyester fabric. The pillow body cover may be a disposable liquid-resistant material suitable for protecting all surfaces of the tubular pillow body.
Accordingly referring to yet another aspect, a method is disclosed herein for providing a tubular pillow in accordance with an embodiment. The method may include providing a pillow body as described herein. Further, the method may include covering the pillow body with an option of removable covers as described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustration, there is shown in the drawings exemplary embodiments; however, the invention is not limited to the specific methods and instrumentalities disclosed. In the drawings:
FIG. 1 is a top view of the body of a pillow body before attachment of its ends in accordance with an embodiment of the subject matter disclosed herein;
FIG. 2 is a perspective view of the pillow body shown in FIG. 1 with its ends positioned for attachment to one another;
FIG. 3 is a perspective view of the tubular pillow body shown in FIGS. 1 and 2 wherein its ends are attached such that the pillow body forms a tube shape having a central tunnel, presenting as a tubular pillow body;
FIG. 4 is a perspective view of a removable, tubular pillow cover for covering the pillow body shown in FIGS. 1-3 according to an embodiment of the subject matter disclosed herein;
FIG. 5 is a perspective view of the cover shown in FIG. 4 being positioned over the exterior of the assembled tubular pillow body according to an embodiment of the subject matter disclosed herein;
FIGS. 6 and 7 are perspective views of another embodiment of assembling a cover on a pillow body in accordance with an embodiment of the subject matter disclosed herein;
FIG. 8 is a perspective view of an assembled tubular pillow with a removable cover encasing only the exterior surface of the pillow body according to an embodiment of the subject matter disclosed herein;
FIG. 9 is a perspective view of an assembled tubular pillow with a cover encasing the interior tubular surface and exterior surface according to another embodiment of the subject matter disclosed herein;
FIG. 10 is a perspective view of a user using the tubular pillow according to an embodiment of the subject matter disclosed herein;
FIG. 11 is an end view of the tubular pillow shown in FIG. 8 ; and
FIG. 12 is a cross-sectional end view of the tubular pillow shown in FIG. 9 .
DETAILED DESCRIPTION
The subject matter of the present invention is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventor has contemplated that the claimed subject matter might also be embodied in other ways, to include different elements similar to the ones described in this document, in conjunction with other present or future technologies.
Tubular pillows according to various embodiments disclosed herein may include fastening elements at opposing ends that connect to each other to form a central tunnel for multiple uses in various environments. An exemplary use of the tubular pillows disclosed herein includes use by a caregiver handling an infant or small child. It is also beneficial for parents, nurses, and other caregivers when caring for larger children, especially, for example, sick children who require continued comforting and holding by a caregiver for extended periods of time. Still another exemplary use would be as a protection of the elbow, knee, or ankle for persons confined to a wheelchair or bed such as, for example, arthritic patients and those recovering from injury or surgery.
In one embodiment, a tubular pillow may be 12 inches wide, with an inner central tunnel circumference of approximately 24 inches, and is approximately 15 inches long. The pillow may include two protective washable cover designs. One cover may be a fabric designer cover that covers only the exterior surface of the pillow. Another removable cover may protect both the interior and exterior surfaces from soil and body perspiration. In addition, a medically-approved disposable cover of liquid-resistant material may cover the inner tunnel as well as the exterior surface of the pillow. Alternatively, the pillow ticking may be constructed of a designer material and not require a cover for private use. In a setting such as a hospital, daycare center, or nursing home, a variable model of the pillow ticking may utilize a fabric that meets federal and state governmental guidelines for infection control as understood by those of skill in the art. For ease in laundering, the tubular pillow cover is removed and the tubular pillow is disassembled to a flattened position.
The pillow may also be useful as an arm, ankle, or knee protection for patients recovering from a trauma or surgery, such as, for example, knee replacement surgery. For example, the pillow can aid as a shield on the extremity to prevent from uncomfortable contact with: an opposing knee when sleeping on one's side during convalescing; a chair arm that does not provide a soft comfortable surface; or accidental contact with other surfaces or objects that may cause additional pain or injury, such as a side rail on a hospital or nursing home bed, leg extensions, and arm rests on a wheelchair.
FIG. 1 illustrates a top view of a body A of a tubular pillow before attachment of its ends in accordance with an embodiment of the subject matter disclosed herein. Referring to FIG. 1 , the tubular body A is shown in an “unattached mode” wherein opposing ends 2 and 4 are unattached such that the pillow is flat. When ends 2 and 4 are attached, the pillow body A forms a tube shape having a central tunnel, as shown and described in more detail herein below.
Ends 2 and 4 can be attached to one another using a hook-and-loop mechanism. Particularly, the length of end 2 can have a plurality of buttons 8 attached thereto, and the length of end 4 can define a plurality of holes 7 configured to mate with the buttons. Thereby, ends 2 and 4 can be attached to one another and can be detached from one another. In an alternative example, ends 2 and 4 may be attached by a hook and loop fastener product, such as, for example, the product known as VELCRO® brand product, which is produced by Velcro Industries B.V. of the Netherlands. The hook-and-loop pieces of the VELCRO® brand product can extend all or a portion of the lengths of the ends. As will be appreciated by those of skill in the art, any other suitable mechanism may be used for attaching and detaching the ends of the pillow body.
The pillow body A can have a size of about 15 inches×26 inches. Particularly, the pillow body A also includes opposing linear edges 1 and 3 having a length of about 26 inches. The lengths of ends 2 and 4 are each about 15 inches, although the ends' lengths may be any other suitable length. Alternatively, the linear edges and lengths of the ends may have any other suitable length or shape.
The pillow body A includes a substantially rectangular-shaped ticking side 5 and an opposing side ticking 6 (shown in FIGS. 2 and 3 ). The pillow ticking can be constructed using any suitable material such as, for example, a liquid-resistant material. For example, the pillow ticking can be made of nylon. Alternatively, for example, the ticking of the pillow body A can be made of a cotton fabric, polyester fabric, or a combination polyester/cotton fabric. In an infection control environment, for example, the pillow ticking may be a medical grade fabric such as HERCULITE® SURE-CHEK® material (produced by Herculite Products, Inc. of Emigsville, Pa.), or the like, which is liquid-resistant and has an antimicrobial protection.
The edges of the sides may be sewn together or otherwise suitably attached together for forming an interior space in which a substantially soft and resilient material is enclosed. For example, the interior space can contain hypoallergenic fiberfill, down, foam, or the like. The soft and resilient material can substantially fill the interior space of the pillow body ticking for providing suitable comfort to a user.
FIG. 2 is a perspective view of the pillow body A with ends 2 and 4 near one another for attachment to one another. FIG. 3 is a perspective view of the pillow body A, wherein ends 2 and 4 are attached such that the pillow body forms a tube shape having a central tunnel 9 .
FIG. 4 is a perspective view of a removable, tubular pillow cover B for covering the pillow body A according to an embodiment of the subject matter disclosed herein. Referring to FIG. 4 , the cover B is made of a washable material, which can be made of cotton, polyester, a combination thereof, or the like fabric material. The cover B is shown at a stage in its construction. The cover B is intended to protect the pillow body A, such as the outer side 6 and/or central tunnel 9 , from soil. As such, the cover B has two opposing ends 12 and 13 attached together with a hem 10 and 11 , which can vary in depth, such as, for example, 1.5 or 2 inches or any suitable depth. The opposing lengths 12 and 13 are superimposed on each other by folding the rectangular fabric material of the cover B with the printed or exterior surface 15 on the inner side of the fold 14 , and the back surface 16 of the material on the outside of the fold 14 as shown in FIG. 4 . Once this has been accomplished, the opposing lengths 13 and 14 are then superimposed on each other and a seam sewn 17 to connect the opposing lengths 13 and 14 , thus the open-ended tubular cover B becomes evident. The tubular cover embodiment B is then turned right side 15 out so the seam will be on the inside 16 of the tubular pillow cover B; thus the printed pattern 15 will be visible on the outside, as shown in FIG. 5 . An alternative method would be the use of a pre-woven circular material of the appropriate circumference to cover the tubular pillow embodiment A, with a hem on each end 10 and 11 as seen in FIG. 4 . An infection control disposable model of the tubular pillow cover embodiment B would not require a hem 10 and 11 on either end.
FIG. 5 is a perspective view of the cover B being positioned over the exterior of the assembled tubular pillow A. This design protects only the exterior 6 of the tubular pillow A. The tubular pillow cover B can extend approximately two inches beyond opposing ends of the assembled pillow body A as shown in FIG. 8 .
FIGS. 6 and 7 are perspective views of another embodiment of assembling the cover B and pillow body A. The assembly of this embodiment can protect the surface of the central tunnel 9 , as well as the exterior surface of the pillow body A when assembled. Before the buttons 8 and the holes 7 are connected, the cover B is slipped over the pillow body A as shown in FIG. 6 . The pillow body A and the cover B are then positioned as shown in FIG. 7 for allowing user access for connecting the buttons 8 and the holes 7 at opposing ends 2 and 4 similar to the technique used in FIGS. 2 and 3 .
FIG. 8 is a perspective view of the assembled tubular pillow C with a removable cover B encasing only the exterior surface 6 of the pillow body A according to an embodiment of the subject matter disclosed herein. The cover B can extend approximately 2 inches beyond the opposing ends of the pillow body A. The hem 10 and 11 may be omitted and substituted with a trim or edging for designer purposes.
FIG. 9 is a perspective view of an assembled tubular pillow D according to another embodiment of the subject matter disclosed herein. The tubular pillow D has the cover B for protecting the opposing sides 5 and 6 of the pillow body A from body perspiration and soil.
FIG. 10 is a perspective view of a user using the tubular pillow according to an embodiment of the subject matter disclosed herein. Referring to FIG. 10 , the user's arm 20 is extended through the central tunnel 9 of the tubular pillow (C or D). In an example of the use of the tubular pillow, an infant or small child can rest against the exterior of the tubular pillow.
FIG. 11 is an end view of the tubular pillow C as shown in FIG. 8 . This figure shows the cover B covering opposing sides 5 and 6 of the pillow body A.
FIG. 12 is a cross-sectional end view X-X of the tubular pillow D as shown in FIG. 9 . Referring to FIG. 12 , the tubular pillow D is shown assembled as ready-to-use. The cover B covers both the interior channel 9 and exterior surface 6 of the pillow body A.
While the embodiments have been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function without deviating therefrom. Therefore, the disclosed embodiments should not be limited to any single embodiment, but rather should be construed in breadth and scope in accordance with the appended claims. | Variable-use tubular pillows having attachable and detachable ends and related methods are disclosed. According to an aspect, a tubular pillow in accordance with the subject matter disclosed herein may include a pillow body having first and second ends being opposed to one another and being attachable to and detachable from one another. The pillow body forms a tube shape having a central tunnel when the first and second ends are attached. Further, the tubular pillow may include a removable cover for covering the pillow body. | 0 |
REFERENCE TO RELATED APPLICATIONS
This is a divisional application of my earlier application Ser. Nos. 06-429,649, filed on Jan. 29, 1982 and 06-601,392, filed on Apr. 17, 1984. Application 06-429,649 was a divisional application of application Ser. No. 344,110, filed on Jan. 29, 1982, now abandoned, and application Ser. No. 06-601,392 was a continuation in part application of application Ser. No. 344,110 which was filed on Jan. 29, 1982, now abandoned. Application Ser. No. 06-344,110 was a divisional application of application Ser. No. 119,349, which was filed on Feb. 07, 1980; now abanonded, whereof benefit is claimed herewith. Application Ser. No. 06-429,649 is now U.S. Pat. No. 4,685,380, issued on Aug. 11, 1987 and application Ser. No. 06-601,392 is now U.S. Pat. No. 4,624,174, issued on Nov. 25, 1986.
BACKGROUND OF THE INVENTION
It is custom to use multi-stroke hydrostatic motors as high-torque motors. Compared to single stroke motors the multi-stroke motors give a higher torque.
After temporary successes and applications the number of multi-stroke motors has now decreased.
The invention therefore inquires deeply into the technology of multi-stroke motors and discovers the reasons why the common multi-stroke motors have lost so many applications.
After the mentioned deep inquiry into the reasons of partial failure, the invention discloses novel means, which increase the power and efficiency of multi-stroke motors or pumps so drastically, that the novel motors are now capable of higher power per size and weight and at the same time are capable of working with a higher overall efficiency.
FIELD OF THE INVENTION
The invention deals in part with fluid motors or pumps, wherein each piston performs at a single revolution of the rotor a plurality of power strokes and reciprocal strokes.
DESCRIPTION OF THE PRIOR ART
The prior art provides a number of multi-stroke motors, but seldom multi-stroke pumps. The multi-stroke device is especially suitable for high torque motors of not too many revolutions per unit of time.
In the former art the rotor has working chambers, commonly radially extending cylinders, wherein pistons reciprocate. The pistons extend outwards of the pistons and carry radially outwards of the rotor roller or other guide members which are rolling along a multi-stroke cam in the housing of the device. The multi-stroke cam is provided with inwardly and outwardly inclined faces, whereat the rollers run and thereby move the pistons inwards in the cylinders or allow them or force them to move outwards in the cylinders.
The inclination of the mentioned inclined faces actuates a tangential or lateral force onto the piston, when the piston is subjected to high pressure fluid in the respective cylinder. In other words, the radially directed force of the high pressure fluid in the cylinder onto the bottom of the respective piston is transformed into a radial and a tangential component of forces by the angle of inclination of the respective guide face of the stroke guide. The mentioned tangential component of force is sometimes also called a lateral force, because when seen in the direction of the axis of the piston, the tangential force acts not in the direction of the axis of the piston but laterally thereto. Seen in the overall structure of the device, the description as tangential force appears to be more proper, because the force acts in the direct direction of the torque, which is a tangential direction relative to the rotor.
The mentioned lateral or tangential component of force on the piston is during the power stroke of the piston transferred in the former art by the outer face of the piston onto the wall of the cylinder and thereby the rotor is revolved and obtains a torque.
SUMMARY OF THE INVENTION
The invention discovers, that very drastic and novel steps must be taken in order to obtain an advancement of the multi-stroke devices. These steps have to be:
First: The stroke of the pistons must be increased per given size in order to increase the power.
Second: Tangential fluid pressure fields must be set between the piston walls and the cylinder walls in order to be able to carry the tangential load.
Third: Means must be found to control the flow of fluid pressure into the fluid pressure pockets at power strokes and to cut the supply of pressure off at the reciprocal strokes.
Fourth: The actuation area of the tangential load transfer onto the piston must be transferred from a location radially outward of the cylinder to a location inwards of a cylinder or along a cylinder wall portion.
Fifth: The inclination angle of the stroke guide faces must be increased for extremely high torque applications, and,
sixth: The means to improve the devices must be in balance with each other and complement each other in order that disturbance of one of the features by the other or others is prevented.
The invention now discovers the means, which can materialize the required steps and applies them singly or in most cases in combination. Thereby the invention attempts to obtain the following aims and objects of the invention:
One object of the invention is to provide to pistons in radial piston devices transfer bodies which carry front and and rear rollers to let the rollers run along a multi-curved guide path for guiding the piston strokes of the pistons.
Another object of the invention is to set rollers of transfer bodies in multi stroke radial piston devices laterally of the medial portions of the pistons in order to align them radially with the centers of fluid pressure pockets in the pistons.
A still further object of the invention is to provide effective thrust bodies in a control body in a rotor's hub for securing a good sealing of the control arrangement in the rotor's hub to effectively control the flow of fluid into and out of working chambers in a rotor wherein the control body is applied with at the same time preventing excessive leakage in the device.
Still another embodiment of the invention is to set piston shoes axially endwards of the piston onto a piston crossing pin for the running of slide shoes on the piston stroke guide faces of the piston stroke guide whereby the slide shoes are borne on the mentioned pin and fluid pressure pockets with passages for fluid are provided to the pin and slide shoes in order to secure a durable swing of the respective portions with small friction.
Another object of the invention is to secure an extremely long piston stroke in order to obtain a high efficiency of the device by having a long piston stroke on a guide face of a small diameter.
And further aims and objects of the invention will appear in the description of the preferred embodiments and in the appended claims.
In this specification and in its claims the word "pivotion" defines a "pivotal movement". The term "pivotion" is known in the patent literature from U.S. Pat. No. 4,387,866.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 also shows a longitudinal sectional view through an embodiment.
FIG. 2 is a sectional view through FIG. 1 along line K--K.
FIG. 3 is a longitudinal sectional view through an embodiment.
FIG. 4 is a sectional view through FIG. 3 along line XI--XI with the exception, that the section through members 511, 551, 552 runs partially parallel to the line with arrows XI--XI of FIG. 3.
FIG. 5 is a longitudinal sectional view through a further embodiment.
FIG. 6 is a sectional view through FIG. 5 along line XV--XV.
FIG. 7 demonstrates another embodiment of the invention.
FIG. 8 is a sectional view through FIG. 7 along line XVII--XVII.
FIG. 9 is a longitudinal sectional view through another embodiment.
FIG. 10 is a sectional view through FIG. 9 along line XIX--XIX.
FIG. 11 is a partial section through a further embodiment.
FIG. 12 is a sectional view through FIG. 11 along line XXI--XXI, and;
FIG. 13 is a view onto a portion of FIG. 1 along the arrowed line M--M of FIG. 1.
As far as the Figures illustrate embodiments, they show embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 demonstrate in a housing 61 an embodiment of the invention which illustrates at the same time two different means of the invention. FIG. 2 is a section along line K--K of FIG. 1.
This embodiment illustrates two pistons 75,85 provided in respective cylinders, f.e. 70, of a rotor with each of the pistons individually bearing a stroke transfer body 4 with a neck 2. The neck 2 has here axial extensions 78 and the axial extensions 78 carry distanced from the middle in peripherial direction or in the direction of rotation two pairs of rollers 74. Each pair of rollers 74 has a forward roller and a rear roller on a forward holder 73 and on a rearward holder 72. Since the load is now carried by four rollers instead of by only two rollers, the rollers may now be ball or roller bearings 74. This arrangement of the first embodiment in these two Figures eliminates the requirement of pivot-angle limitation, because the forward and rear rollers 74 define the angle of pivotion when they run along the respective inward or outward guide faces 242 or 243 of the portions 251,252 of the stroke guide 211. The recesses 29 and passages 23,31 for flow control to pockets 30 can be the same as in the embodiments of my parental application, now patent 4,624,174.
In this embodiment of the invention in FIGS. 1 and 2 is the provision of cylinders or chambers 70 spaced away from the medial center 71 of the rotor 68. These chambers 70 extend beyond the middle 71 deeply into the rotor 68 and almost to the opposite diametrical outer face 117 of the rotor. The pistons can thereby do a very long stroke. Rotor 68 has piston guide extensions 168, which extend from the rotor radially outwards from the rotor's outer diameter 117 to partially enter into the space between the stroke guides 251,252 of stroke guide 211.
This is seen by pistons 75 and 85 whereof 75 has an innermost and piston 85 has an outermost location. Channels 69 are the channels for the transfer of fluid into and out of chambers 70. Bearings 76 carry the rotor 68 and a shaft seal 178 may be provided.
The stroke transfer bodies 4 which are borne in beds 1 of the pistons 75 and 85, pivot at the running of the device around their axes 4. The pistons have fingers or extensions 26 which extend radially outwardly beyond the necks 2 of the transfer bodies to be guided on guide faces 13,14 or 15,16 of the stroke guide extensions 168. Holders 25 may be provided between the extensions 26 to prevent escape of the transfer bodies 4 from their beds 1 in pistons 75 or 85. The rotor 68 has radially outwardly open recesses 18 for the temporary reception of the rollers 74 during the radially inner portions of their reciprocation and running along the piston stroke guide faces 242,243. It is easily and directly visible from FIG. 1 that the forward and rearward rollers 74 define the pivotal movement of the transfer bodies in their beds in the pistons. Since FIG. 1 illustrates a device for either clockwise or counterclockwise revolving of the rotor, the front rollers 72 become rear rollers 73 and vice versa at reversal of the rotary direction of the rotor.
FIG. 13 is a view onto the transfer body 4, its neck 2, its portions 78,72,73 and its rollers 74 seen from the arrowed line M--M of FIG. 1. Since this line crosses portions of the extensions 26 and 168, these portions are seen in sectional views in FIG. 13 and are, respectively, provided with hatching lines.
FIG. 1 is also a cross sectional view through FIG. 2 along the arrowed line in FIG. 2. However, in order to illustrate more clearly the relationship between the rollers 74 and the piston stroke guide faces 242,243 on the piston stroke guide bodies 251,252 of the piston stroke guide 211, the rollers 74 and the piston stroke guide bodies 251,252 are partially and between breaking lines, shown in sectional views with hatching lines along the line "N" of FIG. 2.
Alternatives, other details, features or possibilities of the embodiments of this specification may be found in the earlier mentioned parental U.S. Pat. Nos. 4,624,174 or 4,685,380. FIGS. 3 and 4 illustrate again two other embodiments of the invention. The chambers or cylinders are chambers 70 of FIGS. 1 and 2, which provide the extremely long piston stroke and which are defined thereby that their axes are laterally distanced from the center 71. The arrangement is in FIG. 4 a section along line XI--XI of FIG. 3.
The first embodiment of the these FIGS. 3 and 4 is, that a plurality of chamber groups, which are axially distanced from each other, are provided on the rotor.
The second embodiment of the invention, illustrated in FIGS. 3 and 4 is, that common piston shoes of my elder or co-pending patent or patent applications can be used. The requirement of pivot-angle limitation stoppers is hereby also spared. That is obtained thereby, that the stroke guide has cylindrical inner faces which form the inclined inward and outward guide faces. In this case every piston group has only one inward and one outward stroke at the same revolution, because the multiples of strokes per revolution are obtained by the application of the multiple groups of chambers. The rotor 80 has correspondingly a plurality of radial extensions 415 or 416 and there must be a medial portion 511 with guide faces on the stroke guide arrangement. Since my elder patent-piston shoes can be used in these figures, they can be utilized for self-suctioning of fluid. The device is insofar also suitable as a self-suctioning pump. The traction rings 81 with traction faces 82 are therefore provided, when so desired, to guide the piston shoes 83 outwards by embracing their end portions radially from the inside. Since the outer faces 84 of the piston shoes 83 define the angle of inclination or of pivotion, there is no requirement for pivot-angle limitation faces or stoppers in this embodiment. The required arrangement of the fluid pressure pockets 30 and the control of flow of fluid to them can be applied as in my U.S. Pat. No. 4,374,486. The fluid pressure pockets 87 in the piston shoes are equal to those in my patents, for example as in my U.S. Pat. No. 3,951,047. Novel, however, is the axial shortness of the piston shoes and that is thereby another object of the invention. The piston shoe of this embodiment has the novel feature, that its axial length is about equal to the diameter of the piston whereto it is associated. Thereby the fluid pressure pockets 87 are led radially above the piston and any lateral deformation of the piston shoe's lateral end portions is thereby prevented.
The plurality of chamber groups and piston groups, which are axially distanced from each other in rotor 80, are set with their axes through the radial faces 91 and 92. Channels 69 and 89 demonstrate samples for their location in the rotor and for their control and association to the ports 93,94,95,96. Since the chambers or cylinders extend almost through the rotor 80, the passages or channels are not, as usual in that half of the rotor where the pistons show out of the rotor, but on the diametrically opposite half of the rotor. This must be recognized when setting the controls for the flow of fluid to the chambers 70 and out thereof. Similar matters should be recognized when building the device of FIGS. 1 and 2.
The one chamber group may contain the pistons 85 and the other the pistons 86. FIG. 3 also demonstrates by way of example radial flow control faces or axial flow control faces, namely, the rear end face of rotor 80 and the cylindrical faces 98. In the right portion of FIG. 11 the very long arm 99 of torque which is obtained by the arrangement of the very deep entering-long-stroke pistons 85,86 of FIGS. 1 to 4 and which forms with pressure pocket center 530 the torque-arm 99 multiplied by force 530 of the pocket 30, is also illustrated.
The piston shoes 83 are guided on the guide faces 43. Passages 23,31, pockets 29,30, beds or faces 45,46, axes 4, holders 25,54, outer faces 84, piston portions 26, wall faces 13, and bearings 76 serve to control the operation of the pistons and piston shoes respective to neighboring members. Bearings 76 carry the rotor 80 in the housing 61 and piston stroke actuator--or guide--rings 551,511,552 are located in the housing 61 and form the guide faces 43 to guide thereon the outer faces 84 of the piston shoes 83.
FIGS. 5 and 6 illustrate another embodiment of the invention, which does not require pivotion and pivot-limitation means of the transfer body.
This feature is obtained by setting the transfer of fluid and the control of flow of fluid to the pockets 30 not through the respective pistons but through the rotor. The application of thereby simplified transfer bodies 3 is very convenient. However the application of the flow and flow control through the rotor 8 to the pockets 30 in the pistons 29 requires an additional work and often even the insertion of bushes 471 into the rotor as well as fastening of them by holders 472 to the rotor 8 in order to provide the chambers or cylinders 6 in the bushes. The rotor channels or passages are shown by passages "a". In this embodiment a number of referentials are letters, because the Figures do not provide enough space for the writing of large digits. Control body 602 passes fluid through entrance channel "D" and delivery ports "d" through the channels "a" into the chambers 6 and out thereof through passages or channels "a" and exit ports "e" through exit channel "E". The exits and deliveries are reversed, when the device shall revolve in opposite direction or when it becomes changed from motor to pump or vice versa. The rotor 8,15 or bush 471 has a pair of balance-fluid delivery passages 477 and 474 whereof one extends from the wall face 13 or 14 in the rotary direction and the other in the opposite direction, while they may extend into collection chambers 473 or 478. In any case they communicate to a pair of balance-fluid delivery lines 475 and 476 with one separated delivery line to each separated delivery passage 474 or 477. The delivery lines 475 and 476 port into balance fluid control ports 479 or 480 respectively. The control ports 479 or 480 may be provided on the control body 602 or on a cover or portion of the housing or of the device, depending on actual design and desire. In any case, since the delivery lines 475 and 476 revolve with rotor 8, the control ports 479 and 480 are satationary in order that the lines run over them. When the ports 479 and 480 are laterally, axially or radially distanced from each other, a number of ports 479 and/or 480 may be applied and may also be equal to the number of strokes and guide face sets 43,44. The ports 480 are then communicated to exit channel E and ports 479 to delivery channel "D" or vice versa.
Ports 479 extend over the outwardly inclined guide face 43 areas and ports 480 over the inwardly inclined guide face areas 44 or vice versa. Thereby it is obtained, that at power strokes the respective pocket 30 is communicated to the power channel D or E of higher pressure and the other pocket 30 of the same piston is discommunicated from the power or high-pressure channel D or E. The device of these Figures is an example. The passages, lines, ports etc. can also be set in other places, when suitably designed and machined and when care is taken that they obtain the aim of this object of the invention. The passages 474 and 477 are the extension of the pockets 30 into the walls of the chambers. The fluid pressure pockets could in this embodiment also be completely located in the walls of the chambers 6, but to maintain them in the center of attack of the lateral forces it is better to keep the pockets in the pistons and set the delivery passages 474 and 477 accordingly. The collection chambers 473,478 may facilitate the radial distances of the passages 475,476,474,477 in order that the mentioned passages, ports and like can be easily and straight or under right angles become machined. The passages, lines and collection chambers and other means are provided with referentials at only one chamber 6 because they are similarly provided to the other chambers 6.
FIGS. 7 and 8 illustrate by referential 610 the control body for radial flow, by referential 611 the rotor hub of rotor 612, by referential 613 the space which extends normal to the axis 614 of control body 601 through control body 610 and which contains moveably along the axis 615 of space 613 the thrust members 616 and 617 with their outer faces 618,619 with which they seal along the inner face 611 of the rotor 612. The thrust chamber 613 between the thrust members 616 and 617 is filled with high pressure fluid through one-way valves 621,622 and fluid is passed to the balancing pockets which are shown by referentials 622 and 623 out of respective channels 624,625 over moveable seals 626,627 and passages 628 and 629. The thrust members 616 and 617 also form the control ports 630 and 631. By their thrust against the face 611 of the rotor 612 a tightly sealed flow to and from chambers 6 is obtained without any disturbance of the control- or closing arches 632 and 633 of the control body 610. This embodiment can also be applied in single-stroke devices and not only in multiple stroke devices.
The dotted lines 702 define or indicate the axial ends of the control ports 630,631 by way of example. Control body 610 may be provided with thrust chambers 690 to contain therein seals 691 which are to be pressed by the fluid in chambers 690 against the respective portions of face 611 of rotor 612 for closing and sealing the closing arches between the low- and high-pressure areas of the device.
FIGS. 7 and 8 further illustrate still another embodiment of the invention, namely a slide-shoe arrangement. The piston 640 has a longitudinal first axis extending concentrically in the radially extending passage 23 and a thereto normal second axis 650. Second axis 650 is thereby normal to the longitudinal axis of passage 23 of the piston and also parallel to the axis 614 of the rotor 612 or of the control body 610. A bore without referential number extends around the second axis 650 and the piston 640 carries in said bore the bar 641 which is usually a simple cylindrical bar. The ends of bar 641 extend out of piston 640 and carry on the ends of bar 641 the slide shoes 642 and 643, The slide shoes 642 and 643 are able to slide along the stroke guide end portions 51 and 52. The slide shoes 642,643 have in their radial outer faces the fluid pressure pockets 87 to reduce the load and friction between the slide shoes and the stroke guides 51,52. The stroke guide faces are in this embodiment cylindrical inner faces to permit the simple outer faces of the slide shoes 642,643. Passages 23 and 20,647 are leading fluid under the pressure equal to that in the chamber 6 into the fluid pressure balancing recesses 87. The pressure in pockets 87 is high pressure at power strokes. Guides 646 may be provided in the device to prevent axial or other dislocation of the bar 641 or of slide shoes 642 and 643.
In order to obtain the desired object of the invention, namely to provide additionally active tangential fluid pressure balancing pockets 30 in the pistons, the shoes 642 and 643 are arrested by arresting means 644 to prevent pivotion or excessive pivotion of the slide shoes relatively to the bar 641. The effect thereof is, that under the gradually changing angle of pivotion of the slide shoes 642,643 along stroke guides 51,52, the shoes 642, 643 subject the bar 641 to pivot in unison with the slide shoes 642 and 643. The bars 641 are thereby able to receive a flow control recess 29, whereby the flow of fluid under pressure through the second piston passages 31 into pockets 30 is obtained in timed relation to the pivotion of the slide shoes 642 and 643.
The embodiment illustrated in FIGS. 9 and 10 shows a stroke actuator with plural revolutions at each single revolution of the rotor.
Rotor 8 has working chambers 6. Pistons are not shown therein and piston shoes or slide shoes are also not shown, because those already known from the earlier discussed Figures. The stroke guide 11 has a concentric cylindrical outer face which is borne in bearing 675, whereby the stroke guide 11 is borne in bearing 675. Stroke guide 11 has also an eccentric inner face, which forms the guide face 42. It is cylindrical but eccentrically provided relatively to the bearing 675. Gearing means are provided to revolve the stroke guide 11 a plurality of revolutions at each single revolution of the rotor 8. Thereby the multiple strokes are provided and the device is thereby a multi-stroke device. The gearing means may be a matter of design or choice. The Figures, however, show an example of possible gearing means. Shaft 63 or rotor 8 may carry a first gear 679. The first gear 679 may over interim-gears 661,662,663 and shaft 681 drive the second gears 664 to engage the third gears 678 of stroke guide 11 to revolve the stroke guide 11 a plurality of revolutions at each time when the rotor 8 does one single revolution. Supports 660 and/or 668 may carry the bearing 675 or shafts of interim gears. An outgoing second gear 664 may drive another set of medial gears 666,667,668, to drive the fourth gear 669. Fourth gear 669 is attached to the control body 670 with passages 671 and 672 to revolve the control body 670 with suitable revolutions along control ports 673,674 for the control of flow of fluid into and out of chambers 6 in suitable timed relation and angular relation with the rotation of the rotor 8 and the multiple revolutions of stroke guide 11. Each piston assembled in one of the chambers 6 does thereby a plurality of power strokes and directionally opposed non-power strokes at each revolution of the rotor 8 while the torque of the device as well as the flow quantity of fluid therethrough at each revolution of the rotor 8 is multiplied compared to a typical single stroke per revolution device.
The embodiments of FIGS. 11 and 12 illustrate the non-circular, for example rectangular, cross-sectional area through a working chamber 706.
The arrangement makes it possible to use the maximum of space through an axial size of rotor 708. While the cylinder uses only a small place in the neighborhood of the next piston, the rectangular space of the device of these Figures permits a fullest possible utilization of the size of the rotor 708 to obtain a maximum of flow-through quantity of fluid through the rotor of a given size. That increases the torque and power of the device over that of common radial piston machines with cylindrical pistons and working chambers.
The non-circular or rectangular working chambers may be provided radially into the rotor 708 or they may be produced axially through a medial rotor portion 708, whereonto end portions 709,710 may be fastened to plane end faces 701 and 702. The pistons are receiving complementary cross-sectional areas and configurations to closely seal in the chambers 706 and to reciprocate therein.
Control bodies, for example, those like 610 of FIGS. 7 and 8, may have in respective beds 690 seal bodies 691 for the reduction or prevention of leakage from the high-pressure to the low-pressure side of the control body 610 over a respective control arch 631 thereof.
When the chambers 6 are cylinders and have narrowed rotor passages, which are shown in others of the Figures, but not in FIG. 7, the axial extent of the thrust members 616,617 of FIGS. 7 and 8 can become shortened to the dotted lines 702 in FIG. 7. The fluid pressure pockets 622 and the thereto leading arrangements 628,629,626,627 can then be spared and be eliminated from the embodiment of the Figures. By such axial shortening of thrust bodies 616 and 617 and the elimination of the balancing pockets 622,623, a less expensive arrangement is obtained. The "outcuts" are depressions or recesses. | The former art provides multi-stroke hydrostatic motors, which perform at a single revolution of the rotor multiple inward and outward strokes of the pistons. A high torque was thereby obtained. The invention discovers, that the know multi-stroke motors have still relatively short piston strokes in relation to the diameter of the rotor.
The invention increases the efficiency of multiple stroke motors by the provision of control communications to control the flow of fluid pressure into pockets open to the piston faces and cylinder walls, whereby the torque of the rotor is transferred from the pistons to the cylinder walls by high pressure fluid in the pockets. The invention also provides radial guide extensions to enlarge the stroke of the pistons in a given size and weight of the device combined with the partial movement of the pockets along the guide extensions. | 5 |
PRIORITY DATA
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/530016 entitled “METHODS AND SYSTEMS TO PREPARE FUNCTIONALIZED SUBSTRATE FROM DISULFIDE BOND-CONTAINING MATERIAL,” filed on Sep. 1, 2011, and U.S. Provisional Patent Application Ser. No. 61/530012 entitled “METHODS AND SYSTEMS OF GRAFT POLYMERIZATION ON A FUNCTIONALIZED SUBSTRATE,” filed on Sep. 1, 2011, both of which are incorporated by reference in its entirety.
FIELD
[0002] This disclosure described herein relates generally to methods and systems to generate a customized functionalized substrate by modifying a disulfide bond-containing material in preparation for desired chemical and other reactions, processes and methodologies.
BACKGROUND
[0003] Petroleum is a commodity that is becoming more expensive, impacting the cost of plastic materials and ultimately end-products. Also, petroleum is a non-sustainable material and is subject to geopolitical and environmental forces that further impact cost and future availability. Therefore, an alternative source of chemical feedstock for the production of polymers and for other chemical reactions is desirable, one that is not subject to geopolitical and environmental influences.
[0004] Feathers may provide such an alternative. Poultry feathers are composed of approximately 90% keratin and are a plentiful and readily-available byproduct in the food processing industry, with most of the material being disposed of as waste. However, previous documented efforts using chicken feathers as a chemical feedstock have either used solvents or harsh chemicals or have been limited for the purpose of extracting the keratin as an end product.
[0005] Once prepared, a functional substrate can be used for a variety of applications. Documented efforts for generation and use of hydrocarbon based nanostructures, films and other building blocks include: generation of short polypeptides that can self-assemble used for nano delivery systems of drugs and compounds across host membranes, filtration systems, and pharmaceutical compositions (U.S. Pat. No. 7,671,258 “Surfactant peptide nanostructures, and uses thereof”); and synthesis of Synthetic Polymer Complements having surface that include functional groups that are complementary to surface sites of targets such as nanostructures or macromolecular targets and capable of interacting with such targets (U.S. Pat. No. 6, 884,842 “Molecular compounds having complementary surfaces to targets”).
SUMMARY
[0006] The embodiments provided herein are directed to methods and systems for generating a customized functionalized substrate. In particular, the embodiments provided herein generate a customized functionalized substrate that can be used for a variety of applications and a variety of chemical and other reactions, processes and methodologies, by modifying a disulfide bond-containing feedstock through the introduction of a disulfide bond breaking material.
[0000] three
[0007] In one embodiment, a process of preparing a functionalized substrate, is provided. The process includes introducing a disulfide-bond-containing material to a polyfunctional monomer. The disulfide-bond-containing material includes a disulfide bond connecting a first portion and a second portion. The polyfunctional monomer includes at least one first functional group and at least one second functional group. The first functional group includes a disulfide bond breaking material for breaking the disulfide bond. The process further includes performing a solids reaction without the use of water, aqueous solvents or non-aqueous solvents. Performing the solids reaction includes breaking, via the disulfide bond breaking material of the first functional group, the disulfide bond, and forming a second bond between the first portion and the polyfunctional monomer to form the functionalized substrate.
[0008] In some embodiments, the second functional group is a reactive site on the functionalized substrate adapted to facilitate a chemical reaction.
[0009] In some embodiments, the second functional group includes at least one ring, and the ring is adapted to be opened to form at least a third functional group.
[0010] In some embodiments, a feedstock can be customized to provide an alternative to petroleum as a chemical feedstock for the production of polymers. Additionally, the feedstock can be customized for other chemical reactions and processes as by example providing hydrocarbon building block(s) for nanochemistry. Alternatively, the embodiments presented herein are applicable to reclaiming and or reducing waste materials that may otherwise have negative environmental impact.
[0011] In some embodiments, poultry feathers and other keratin based materials can be utilized as a sustainable chemical feedstock for the synthesis and generation of functionalized substrate(s) through the systems and processes described herein. These functionalized substrate(s) may be used, for example, for the production of polymers as well as the production of hydrocarbon and other building blocks for nanochemistry. These functionalized substrate(s) can replace many of the petroleum-based feedstocks at a fraction of the cost and remove a waste material from the environment. For example, keratin is biodegradable, and by judicious choice of the monomers, the end-product can be biodegradable, an attribute increasingly sought after in the industry.
[0012] The embodiments described herein are targeted towards synthesis of a customizable functionalized substrate in preparation for other chemical reactions. The polyfunctional monomer(s) (and their functional groups) chosen for the synthesis are dependent upon the chemical reactions sought to be achieved. In some embodiments, a polyfunctional monomer(s) containing at least one functional group that is a disulfide bond breaking material (e.g., a thiol (—SH) group) is used to break the disulfide bonds, not for the purposes of extracting keratin, but to specifically to prepare the keratin or other disulfide bond-containing material as a functionalized substrate for further chemical reactions. Applications may include the production of plastics, coatings, adhesives, foam insulation and other polymers, as well as applications in other chemistry disciplines.
[0013] Alternatively the functionalized substrate can be customized to provide reactive site chemoselectivity. This may, but need not, occur through the introduction of “protective” functional groups (or materials including protective functional groups) that attach to and prevent the functional groups of the functionalized substrate from reacting other than as desired. This chemoselectivity is desirable for solid phase synthesis and certain nanochemistry applications. The functionalized substrate can also be customized to provide, through reduction or other chemical reactions, a source of peptides and protein chains for solid phase synthesis, nanochemistry and other applications.
[0014] In some embodiments, disulfide bond-containing feedstock(s) are used, which are then synthesized into a customized functionalized substrate through the introduction of selected disulfide bond breaking materials.
[0015] In some embodiments, the processes and systems described herein generate customized functionalized substrates in preparation for further chemical reactions by modifying a disulfide bond-containing feedstock through the introduction of a disulfide bond breaking material (e.g. a thiol (—SH) in a thiol-disulfide exchange) chosen to achieve the desired result. In particular, the described process and system provide a method to functionalize a substrate containing for example, protein, peptides or other materials containing disulfide bonds through the introduction of one or more polyfunctional monomers. The polyfunctional monomer(s) includes at least two functional groups of which one functional group is a disulfide bond breaking material (e.g., a thiol (—SH) group). The disulfide bond-breaking material is used to break the disulfide (S—S) bonds between cysteine residues that crosslink the feedstock and to reform a disulfide bond between one of the cysteine residues and the attacking thiol or other disulfide bond breaking material. The chain length, reactive site, crosslinking and other characteristics of the functionalized substrate and its constituents may be customized by the polyfunctional monomer(s) (M 1 ), and their functional groups, chosen for the functionalization.
[0016] The embodiments provided herein can use protein, peptides, and any material containing disulfide bonds. It is understood that while the embodiments described below describe the use of protein keratin, other materials that contain disulfide bonds such as vulcanized rubber (tires) may be used as the chemical feedstock for production of the functionalized substrate. Keratin is a sustainable chemical feedstock that can be found in avian feathers, hair, wool and other sources.
[0017] Cysteine residue
[0000]
[0000] (illustrated above between the vertical dashed lines), is the fragment of the cysteine amino acid after it has been incorporated into the protein, however missing the H 2 O. In proteins, two thiol groups from two cysteine residues may form a sulfur-sulfur bond (a disulfide bond) crosslinking the protein. The existing disulfide bond is broken by introducing a disulfide bond breaking material (e.g., one containing a thiol (—SH) group), and a new disulfide bond is formed between one of the cysteine residues and the attacking thiol or other disulfide bond breaking material. The other cysteine residue is converted to a thiol. In other embodiments, the other cysteine residue can be converted to other chemical compositions. In one embodiment, a protein, peptide or other material containing disulfide bonds is mixed with polyfunctional monomer(s) (M 1 ) with the generic structure
[0000]
[0000] where HS is a thiol group, R is a generic hydrocarbon, A 1 is another functional group, and A 2 and A 3 are optional functional groups. The polyfunctional monomer(s) is not limited to having three functional groups in addition to the disulfide bond breaking functional group, but may have any number of additional functional groups (A n ). These functional groups that make up A 1 , A 2 , A 3 , through A n can be taken from the standard lists of organic functional groups and include acid anhydrides, acyl halides, alcohols, aldehydes, alkenes, alkynes, amines, carboxylic acids, esters and thiols, as well as additional functional groups known in the arts. A 1 , A 2 and A 3 do not have to be the same functional group. The thiol groups in the polyfunctional monomer M 1 break the disulfide bonds as described above and reform as new disulfide bonds with the polyfunctional monomer M 1 . The unreacted functional groups, for example, A 1 , A 2 through A n , become the reactive sites of the functionalized substrate for the further chemical reactions for which the functionalized substrate was produced. The functional groups are chosen dependent upon the material to be produced or the chemical or other reactions and processes to be performed on or with the substrate. Additionally multiple and different M 1 (s) can be utilized as desired. By example only the following is a partial list of M 1 polyfunctional monomers containing a disulfide bond breaking thiol group:
[0000]
Examples of Polyfunctional Monomers with at least 1 Thiol, M1
Ethanedithiol
Propanedithiol
Butanedithiol
Pentanedithiol
Hexanedithiol
Propanetrithiol
Butanetrithiol
Pentanetrithiol
Hexanetrithiol
Butanetetrathiol
Pentanetetrathiol
Hexanetetrathiol
Hydroxy-ethanedithiol
Hydroxy-propanedithiol
Hydroxy-butanedithiol
Hydroxy-pentanedithiol
Hydroxy-hexanedithiol
Dihydroxy-ethanethiol
Dihydroxy-propanethiol
Dihydroxy-butanethiol
Dihydroxy-pentanethiol
Dihydroxy-hexanethiol
Hydroxy-pentanetrithiol
Hydroxy-hexanetrithiol
Dihydroxy-pentanedithiol
Dihydroxy-hexanedithiol
Trihydroxy-pentanethiol
Trihydroxy-hexanethiol
Hydroxy-pentanetetrathiol
Hydroxy-hexanetetrathiol
Dihydroxy-pentanetrithiol
Dihydroxy-hexanetrithiol
Trihydroxy-pentanedithiol
Trihydroxy-hexanedithiol
Tetrahydroxy-pentanethiol
Tetrahydroxy-hexanethiol
Mercaptoethyl ether
Mercaptopropyl ether
Mercaptobutyl ether
Mercaptopentyl ether
Mercaptoacetic acid
Mercaptopropionic acid
Mercaptobutyric acid
Mercaptovaleric acid
2,2′-(Ethylenedioxy)diethanethiol
3-Mercaptopropyl methyldimethoxysilane
2-Mercaptopropyltrimethoxysilane
Trimethylolpropane tris(2-mercaptoacetate)
Trimethylolpropane tris(2-mercaptopropionate)
Pentaerythritol tetrakis(2-mercaptoacetate)
Pentaerythritol tetrakis(2-mercaptopropionate)
[0018] In one embodiment, disulfide bond-containing feedstock may be utilized for the preparation of a functionalized substrate.
[0019] In one embodiment, various waste materials may be utilized as a feedstock for the preparation of the functionalized substrate.
[0020] In one embodiment, the process may be used to prepare a waste material for biodegradation or recycling, or to otherwise address environmental impact concerns.
[0021] In one embodiment the process incorporates a method to functionalize a disulfide bond-containing feedstock through the addition of polyfunctional monomer(s) M 1 , having two or more functional groups of which at least one functional group is a thiol or other disulfide bond breaking material to break and reform the disulfide bond (S—S) in preparation for other chemical reactions. The disulfide bond containing feedstock is customizable by the choice of the monomers and functional groups utilized in preparation of the customized functionalized substrate, such customization including but not limited to the chain length, reactive site chemoselectivity, physical characteristics (hormone attachment site), crosslinking, etc.
[0022] In one embodiment, the process may be a solids reaction to prepare the functionalized substrate from a disulfide bond-containing feedstock, without the use of water, aqueous solvents or non-aqueous solvents.
[0023] In one embodiment, the process may utilize water or aqueous solvents to prepare the functionalized substrate from a disulfide bond-containing feedstock.
[0024] In one embodiment, the process may utilize non-aqueous solvents to prepare the functionalized substrate from a disulfide bond-containing feedstock.
[0025] In one embodiment, the process may utilize solid phase synthesis to further modify the functionalized substrate, for example to aid in the recovery of the products synthesized, such as peptides.
[0026] In one embodiment, combinatorial chemistry may be applied for the rapid synthesis of a large number of different but structurally related molecules or materials.
[0027] In another embodiment, disulfide bond-containing feedstock comprising or containing biodegradable materials such as keratin may be utilized to prepare biodegradable materials.
[0028] In one embodiment, the disulfide bond-containing feedstock may be vulcanized rubber wherein the disulfide bonds in the feedstock are broken for recovery of the rubber or other constituents, for recycling or biodegradation, or for the purpose of further synthesis or processing the feedstock for use as a functionalized substrate.
[0029] In one embodiment, the functionalized substrate may be used for graft polymerization. In the case of graft polymerization, the other functional group(s) of the monomer(s) M 1 that may be added is dependent upon the type of polymer to be produced. The other functional group(s) includes but are not limited to acid anhydrides, acyl halides, alcohols, aldehydes, alkenes, alkynes, amines, carboxylic acids, esters and thiols. Furthermore, additional monomers M 2 may be added to the aforementioned protein, peptides or other materials including disulfide bonds before, with, or after the addition of the polyfunctional monomer containing at least one thiol group.
[0030] In one embodiment, the functionalized substrate may be used for macromer grafting of prebuilt or existing polymer(s) or other materials. In the case of graft reactions, one or more prebuilt polymers may be reaction grafted to the functionalized substrate, for example, the esterification reaction between an hydroxyl (—OH) terminated polymer and a carboxylic acid (—COOH) group of the functionalized substrate.
[0031] In one embodiment, the functionalized substrate may be customized for nanochemistry applications, such as for use as a building block(s) for nanostructures.
[0032] In one embodiment, the functionalized substrate may be customized for biological or biochemical applications, for example by reacting with, binding with, interlocking or modifying hormones, antibodies or cell walls.
[0033] In one embodiment, the functionalized substrate may be customized for supramolecular chemistry applications, for example reacting with “bucky balls” or carbon nanotubes.
[0034] In one embodiment, the functionalized substrate may be customized for other chemistry disciplines and intra/interdisciplinary chemistries as required for a specific outcome, for example by creating chemoselective sites that are specific to an inorganic atom(s) or molecule(s), or for colorimetric analyses or outcomes.
[0035] In one embodiment the functionalized substrate may be customized to provide specific electrochemical, photochemical, thermochemical, physical and optical properties, individually or together.
[0036] In one embodiment, the process incorporates more than one customized functionalized substrate that may be chained, cross-linked, combined etc.
[0037] In one embodiment the functionalized substrate may be prepared for the purpose of reduction or further processing of the substrate, for example to synthesize individual peptide or other chains or molecules for use in nanochemistry, medical, biochemical or other applications.
BRIEF DESCRIPTION OF DRAWINGS
[0038] FIG. 1 a is an illustration of one embodiment of the functionalization of a disulfide bond-containing feedstock through the introduction of a polyfunctional monomer.
[0039] FIG. 1 b is an illustration of one embodiment of the process flow of the functionalization of a disulfide bond-containing feedstock through the introduction of a polyfunctional monomer.
[0040] FIG. 2 is an illustration of one embodiment of the graft polymerization on a functionalized substrate, and its polymerization without the addition of M 2 monomer.
[0041] FIG. 3 is an illustration of one embodiment of the overview of a graft reaction or macromer grafting on a functionalized substrate made from a feedstock containing or comprising protein, peptides or other materials containing disulfide bonds.
DETAILED DESCRIPTION
[0042] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the inventive concepts may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the described method or process, and it is to be understood that the embodiments may be combined or used separately, or that other embodiments may be utilized, and that design, implementation, and procedural changes may be made without departing from the spirit and scope of the inventive concepts. The following detailed description provides examples.
[0043] The term “chemical reactions” is defined as reactions, processes and methodologies including, but not limited to, chemical, biochemical, biological, electrochemical, optico-chemical, physical or other reactions, processes and methodologies.
[0044] The term “feedstock” and “disulfide bond-containing feedstock” may be used interchangeably and is defined as material comprising or containing proteins, peptides, or other disulfide bond containing materials. Such feedstock may be waste stream materials, for example avian feathers, hair, or wool.
[0045] The term “functionalized substrate” is defined as a material which has been modified through a thiol-disulfide exchange in preparation for other chemical reactions.
[0046] The term “thiol-disulfide exchange” is defined as the reaction occurring between a thiol functional group and a disulfide group. The sulfur atom of the thiol attacks one of the sulfur atoms in the disulfide bond forming a new bond between the attacking sulfur atom and the attacked sulfur atom. Simultaneously, the previously existing disulfide bond is broken and the remaining sulfur atom leavings and reforms as a thiol group.
[0047] The term “supramolecular chemistry” refers to the chemistry and collective behavior of organized ensembles of molecules. In this mesoscale regime, molecular building blocks are organized into longer-range order and higher-order functional structures via comparatively weak forces.”
[0048] The term “nanochemistry” is defined as the science of tools, technologies, and methodologies for chemical synthesis, analysis, and biochemical diagnostics, performed in at least nano litre to femtolitre domains. It is the use of synthetic chemistry to make nano scale building blocks of desired shape, size, composition and surface structure, charge and functionality with an optional target to control self-assembly of these building blocks at various scale-lengths.
[0049] The term “combinatorial chemistry” is defined as the rapid synthesis of a large number of different but structurally related molecules or materials.
[0050] The term “chemoselectivity” is defined as the preferential outcome of one instance of a generalized reaction over a set of other plausible reactions.
[0051] The term “graft polymerization” is defined as a reaction occurring on a functionalized substrate wherein the polymerization occurs at the functionalization site(s). Note that this definition does not assume or require a particular sequence or timing of events, unless specifically stated.
[0052] The term “solid-phase synthesis” is a method in which molecules are bound on a surface and synthesized step-by-step in a reactant solution; compared with normal synthesis in a liquid state, it is easier to remove excess reactant or byproduct from the product.
[0053] The term “macromer” is defined as a polymer with the defined reactive functions at both ends and/or on the chain, which can constitute a building bloc of the final polymers of certain values via suitable chain-extending reactions.
[0054] The term “graft reaction” and “macromer grafting” may be used interchangeably defined as the grafting of a macromer by reaction between a macromer and another chemosensitive site of a polymer or a macromer to another macromer for chain extension.
[0055] The term “cysteine residue” is defined as what is left of a cysteine molecule after the cysteine molecule is incorporated within a protein, peptide or other material containing disulfide bonds.
[0056] The term “functional group” is defined as a group of atoms found within molecules that are involved in the chemical reactions characteristic of those molecules such as but not limited to acid anhydrides, acyl halides, alcohols, aldehydes, alkenes, alkynes, amines, carboxylic acids, esters and thiols.
[0057] The letter “M 1 ” is representative of a polyfunctional monomer containing at least one thiol group and one or more functional groups A 1 , A 2 , A 3 , . . . and A n (n is an integer larger than one).
[0058] The letter “M 2” is representative of a monomer wherein M 2−1 and M 2−2 . . . and M 2−n refer to different monomers utilized in a polymerization process (n is an integer larger than one).
[0059] The letter “S” is representative of a sulfur atom.
[0060] The letters “A 1 , A 2 , A 3 , and A n ” are representative of functional groups that may or may not be the same.
[0061] The letter “R” is representative of a generic hydrocarbon or hydrocarbon chain that may be an alkyl, aromatic, linear, branched or any combination thereof.
[0062] Note that in the following illustrations, superscripts do not denote the number of atoms or functional groups involved (for example S 1 or A 1 ), but are simply used to differentiate between atoms or functional groups for purposes of clarity.
[0063] FIG. 1 a and FIG. 1 b illustrate an overview and process flow of an exemplary functionalization of a disulfide bond-containing feedstock 100 prior to graft polymerization on a functionalized substrate wherein a polyfunctional monomer 115 , 175 is added to the feedstock 105 , 170 to break the disulfide bond 110 and reform a disulfide bond 145 between the cysteine residues and the attacking thiol groups.
[0064] FIG. 1 a is an illustration of one embodiment of the functionalization of a disulfide bond-containing feedstock through the introduction of a polyfunctional monomer, of which at least one functional group must be a thiol or other disulfide bond breaking material, to break the disulfide bonds between the cysteine residues crosslinking the protein and reform new disulfide bonds between the cysteine residues of the feedstock and the attacking thiol or other disulfide bond breaking group.
[0065] FIG. 1 b is an illustration of one embodiment of the process flow of the functionalization of a disulfide bond-containing feedstock through the introduction of a polyfunctional monomer, of which at least one functional group must be a thiol or other disulfide bond breaking material, to break the disulfide bonds between the cysteine residues crosslinking the protein and reform new disulfide bonds between the cysteine residues of the feedstock and the attacking thiol or other disulfide bond breaking group.
[0066] Disulfide bonds 110 are the bonds between two cysteine residues that are part of and sometimes crosslink proteins, peptides or other materials 105 containing the disulfide bonds 110 . At least one polyfunctional monomer M 1 115 including at least one thiol or other disulfide bond breaking group 120 and one A 1 functional group 125 and optionally one A 2 functional group 130 or two functional groups A 2 130 and A 3 135 respectively may be added. In accordance with FIG. 1 b, process and decision flow, the feedstock has been functionalized 185 and is stable and the functionalized substrate may be shipped 190 to a customer for further processing. Functional groups A 1 , A 2 , and A 3 may be any functional group of choice dependent upon the target polymer. Furthermore, multiple and different polyfunctional monomers M 1 115 may be added as required dependent upon the polymer to be produced. Note that this illustration of process and decision flow does not assume or require a particular sequence or timing of events, unless specifically stated.
[0067] Upon adding the polyfunctional monomer(s) M 1 115 to the segment 105 of the protein, peptide or other material containing the disulfide bonds 110 , the initial reaction is the breaking of the disulfide bond 110 by the thiol 120 and reformation of disulfide bond 145 on the segment 105 and formation of a thiol 160 on the segment 165 .
[0068] FIG. 2 illustrates an example of graft polymerization 200 on a functionalized substrate. Disulfide bonds 210 are the bonds between two cysteine residues that are part of proteins, peptides or other materials 205 containing disulfide bonds. At least one polyfunctional monomer M 1 215 including at least one thiol group 220 and a ring 230 capable of polymerizing upon opening may be added.
[0069] Upon adding polyfunctional monomer(s) M 1 215 to the segment 205 of the protein, peptide or other material containing disulfide bonds, the initial reaction is the breaking of the disulfide bond 210 by the thiol 220 and reformation of the disulfide bond 240 on the segment 205 and formation of thiol 250 on the segment 255 .
[0070] After the disulfide bond reformation has occurred, appropriate conditions are established to open the ring 230 on the monomer. The opened ring 275 is then capable of reacting with other rings on monomers 215 , leading to formation of the grafted polymer 295 . Polymerization can be initiated by appropriate means using, for example, heat, UV light, catalyst, etc.
[0071] As one example, the monomer M 1 215 may contain a lactide ring. Upon addition of heat or an appropriate catalyst such as tin (II) chloride, the lactide ring opens and graft polymerization occurs.
[0072] In some embodiments, the monomer M 1 215 includes a second functional group that is a ring bearing functional group that includes a lactone, a lactide, a lactam, and/or a cyclic ether.
[0073] In some embodiments, polymerization can be self-initiated, via a second monomer that is introduced to a disulfide-bond-containing material and a polyfunctional monomer.
[0074] FIG. 3 illustrates an overview of an exemplary macromer grafting polymerization 300 on a substrate containing protein, peptides or other materials containing disulfide bonds. Disulfide bonds 310 are the bonds between two cysteine residues that are part of proteins, peptides or other materials 305 containing the disulfide bonds 310 . A polyfunctional monomer 315 , containing at least one thiol —HS 3 320 , and at least another functional group A 1 330 is added to the feedstock 305 to break the disulfide bond 310 and reform a disulfide bond 340 between the cysteine residues and the attacking thiol groups. Following the functionalization of the substrate 305 , a macromer molecule 360 containing at least one reactive endgroup A 2 is added to the mixture and the grafting reaction between the functional groups A 1 and A 2 occurs resulting in a new bond 370 . An example of this would the reaction between a hydroxyl (—OH) terminated polymer and a carboxylic acid (—COOH) group of the functionalized substrate.
ASPECTS
[0000]
1. A process of preparing a functionalized substrate, comprising:
[0076] introducing a disulfide-bond-containing material to a polyfunctional monomer, the disulfide-bond-containing material including a disulfide bond connecting a first portion and a second portion, the polyfunctional monomer including at least one first functional group and at least one second functional group, the first functional group including a disulfide bond breaking material for breaking the disulfide bond; and
[0077] performing a solids reaction without the use of water, aqueous solvents or non-aqueous solvents, wherein performing the solids reaction includes:
breaking, via the disulfide bond breaking material of the first functional group, the disulfide bond; and forming a second bond between the first portion and the polyfunctional monomer to form the functionalized substrate. 2. The process of aspect 1, wherein the second functional group is a reactive site on the functionalized substrate adapted to facilitate a chemical reaction. 3. The process of aspects 1-2, wherein the disulfide-bond-containing material is a feedstock that includes a protein, an avian feather, a hair, a wool keratin, or a vulcanized rubber. 4. The process of aspects 1-3, wherein the disulfide bond breaking material includes a thiol group, and the second bond is a disulfide bond. 5. The process of aspects 1-4, wherein the second functional group includes at least one of an acid anhydride, an acyl halide, an alcohol, an aldehyde, an alkene, an alkyne, an amine, a carboxylic acid, an ester and/or a thiol. 6. The process of aspects 1-5, wherein the second functional group includes at least one ring, the ring being adapted to be opened to form at least a third functional group. 7. The process of aspects 1-6, wherein the second functional group is a ring bearing functional group that includes a lactone, a lactide, a lactam, and/or a cyclic ether. 8. The process of aspects 1-7, wherein the polyfunctional monomer includes trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(2-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), or pentaerythritol tetrakis(2-mercaptopropionate). 9. The process of aspects 1-8, wherein the polyfunctional monomer includes three or more second functional groups. 10. The process of aspects 1-9, wherein the first and second portions connected by the disulfide bond are cysteine residues. 11. A polymerization process, comprising:
providing a functionalized substrate according to aspect 1, and initiating a polymerization reaction on the functionalized substrate.
12. The process of aspect 11, further comprising:
adding one or more monomers to react with the at least one second functional group.
13. The process of aspects 11-12, further comprising initiating the polymerization reaction using an initiator that includes at least one of a UV light, a thermal initiator, and/or a catalyst. 14. The process of aspects 11-13, further comprising introducing a second monomer to the disulfide-bond-containing material and the polyfunctional monomer, and self-initiating, via the second monomer, the polymerization reaction. 15. The process of aspects 11-14, wherein the second monomer is a macromer.
[0097] With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of the parts without departing from the scope of the present invention. It is intended that the specification and depicted embodiment to be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the claims. | The embodiments provided herein are directed to methods and systems for generating a customized functionalized substrate. In particular, the embodiments provided herein generate a customized functionalized substrate that can be used for a variety of applications and a variety of chemical and other reactions, processes and methodologies, by modifying a disulfide bond-containing feedstock through the introduction of a disulfide bond breaking material. | 2 |
TECHNICAL FIELD
This invention relates to tamper-evident and/or tamper-resistant electronic components, and to ways of making them, and to applications for such components. It is especially, but not exclusively, concerned with electronic components which store or provide data or information.
Tamper-evident means that it is possible to tell that an attempt to subvert the electronic component, to tamper with it, has been made, preferably that it is relatively easy to tell that a tamper attempt has been made. The attempt to tamper may or may not be successful: but a tamper-evident device will have its integrity questioned if it shows signs of tampering. Tamper-resistant means that the component is difficult to tamper with, or that it has been designed to resist tampering in at least one way. Neither tamper-evident nor tamper-resistant mean that a component cannot be tampered with.
The invention has arisen out of the area of timestamping an electronic document with a time in such a way that there is a high degree of confidence that the document was really timestamped at the indicated time and that the time has not been forged. Since the invention arose from such considerations it will be described in that context, but it will be appreciated that it has wider applicability to other areas where it is desired to provide a tamper-evident and/or tamper-resistant component, circuitry, or device.
BACKGROUND ART
It is known in the field of timestamping documents to send a digest or fingerprint of document to be timestamped over the internet to a Trusted Clock—a clock whose integrity can be relied upon (for example relied upon in a court of law). The Trusted Clock then timestamps the digest, crypotographically digitally signs the digest (for example by producing a hash or second digest of the document digest plus time stamp and then encrypting it) and sends the signed and hashed fingerprint or document/digest, back over the internet to the person who requested that the digest be signed. The signing process typically involves encrypting data, often using the PKI infrastructure. Thus the signature, and the evidential reliability of the document and timestamp are time-limited to when the cryptographic keys time expire in reliability (the Certification Authority typically puts a limit on the time for which they say their keys are safe, before they cannot be certain enough that someone could not decrypt encrypted messages without the key). This may result in the need to have a, timestamped signed digest timestamped and signed again, using newer encryption keys before the expiry of the older encryption certificate keys.
This need, and the general rise in Internet traffic, and the rise and projected rise in the requirement to timestamp documents or digests of documents with a reliable time, means that there is likely to be increasingly large demands on the Internet telecommunication pathways, and upon the usage of Trusted Clocks.
Documents or digests of documents that are timestamped need not be share trades, tenders for tendered work, or other “high level” sensitive document digests, but are increasingly more mundane things such as a digest of the log of when a monitored door is opened and closed, and who opened and closed it (e.g. secure doors requiring swipe cards or other user identification means). Connecting a door sensor/actuator to the Internet can be expensive and awkward, as can connecting other sensor/or control devices to the Internet.
It is known for people to try to determine the structure and operational capabilities, and software used, in someone else's microchip, or printed circuit board (PCB) in order to break the law For example in order to bypass security provisions in order to perpetrate criminal activities such as industrial espionage, or even fraud or theft. Internet fraud and computer hacking is a growing problem. Bank fraud and the breaching of the security of computer systems is a growing problem. In some cases changing the time on an electronic record, e.g. putting the clock back, can be used in fraud. For example such “spoofing” of systems can mislead third parties into trusting something they should not trust. It is undesirable to have anyone subverting the function of an electronic device in an undetected manner.
It is known to encase microchips, PCB's or other electronic devices in a polymer matrix to hinder their physical inspection. It is known to shield electronic components electromagnetically in order to prevent the leakage of electromagnetic radiation out from a device (the leaking out of information), and to prevent a device being subjected to incoming e.m. radiation, e.g. probing a device with a prompt and seeing what its responses are, in order to deduce things about the device.
It is known to provide an electronic component such as a microchip and/or a PCB with electronic monitoring to establish whether an attempt to interfere with the component is being made. However, it can be relatively straightforward to avoid the known security systems, for example using a drill to drill down into the component, possibly after X-raying the component to learn more of its structure before drilling.
It is known to have flexible circuit boards where a printed circuit board is printed onto a flexible unitary homogenous sheet of Mylar plastics material.
DISCLOSURE OF THE INVENTION
It is an aim of at least one embodiment of the invention to reduce the need for Internet usage in order to access a Trusted Clock.
It is an aim of at least one embodiment of the invention to provide a tamper-evident/and or tamper-resistant electronic component.
It is an aim of at least one embodiment of the present invention to make it harder to drill into an electronic component to modify it, without the attempt to modify the component being detected. It is an aim of another embodiment of the invention to make it harder to analyse an electronic component, especially undetected.
It is an aim of another embodiment of the invention to provide a Trusted Clock, or a Trusted data store.
According to a first aspect the invention comprises an electronic module having an outer surface and having an electronic component, encapsulant material, and a tamper-evident and/or tamper-resistant barrier: wherein said electronic component is encapsulated in said encapsulant, and said tamper-evident and/or tamper-resistant barrier is disposed between said outer surface of said module and said electronic component and comprises at least a first tamper-detecting layer and a second tamper-detecting layer, said first layer comprising a first sheet element adapted to be monitored by a sensor communicable with said sheet element, said first sheet element having a detectable characteristic detectable by the sensor, said characteristic being detectably different when said first sheet element is whole and unbreached in comparison with when said first sheet element has been holed or otherwise physically breached; and wherein said second layer also comprises a sheet element, a second sheet element, adapted to be monitored by a sensor, said second sheet element having a detectable characteristic detectable by the sensor, said characteristic being detectably different when said second sheet element is whole and unbreached in comparison with when said second sheet element has been holed or otherwise physically breached.
There may be a third, or a plurality of further layers, each of which may comprise a sheet element having a detectable characteristic which changes when the sheet is holed or breached.
The barrier may comprise a multi-layer flexible sheet. By flexible is meant flexible enough to deform under its own weight—i.e. non-self supporting when held horizontally. The sheet may be floppy. It may be about as flexible as a sheet of standard A4 paper, or as the plastics material used for supermarket carrier bags, or about as flexible as flexible circuit boards. The layers of the flexible sheet may comprise plastics materials, or at least some of them may. Mylar is a suitable plastics material. A material that does not shrink or otherwise change in shape or size with time is advantageous, as is a material that can carry a metal layer or film, and a material that will not react badly with the encapsulant. The material of the layers is preferably electrically insulating.
The flexible barrier sheet may have layers having a thickness in the range 1/1000− 30/1000 inch or more; more preferably in the range to 2/1000 to 20/1000 inch or more, and in one embodiment has a thickness of about 2/1000− 5/1000 inch, for example 3/1000 inch. The overall sheet may have a thickness of 5− 100/1000 inch or more, depending on the number of layers. The sheet may have a thickness of >0.2 mm, preferably between 0.2 mm and about 1 mm.
The tamper-detecting layers of the barrier flexible sheet may be bonded together, preferably over substantially the whole of their face-to-face contact. They may be thermally bonded. Alternatively, they may not be bonded together directly, and may be free floating, at least before encapsulation.
Said first and second layers may have a lead connectable to the sensor (s) to which they are adapted to be communicated. Said lead may comprise an electrical pathway.
At least one of said layers preferably comprises a tell-tale pathway adapted in use to carry a signal. The pathway may comprise a meandering convoluted pathway which traverses a substantial part of the surface area of the sheet element that carries it, and which may also cover a substantial fraction of the surface area of the sheet that carries it. The pathway may traverse over substantially the whole of the sheet that carries it and/or may cover about half, or about ⅓ to ⅔, of the surface area of the sheet that carries it.
The pathway may comprise a space-filling pattern. The pathway may comprise a fractal pattern. These are less predictable than regular patterns. The fractal pattern may be a space-filling fractal, such as a Peano fractal.
The pathway may have an overall, general, directionality. There may be a first sheet having a first pathway and a second sheet having a second pathway superposed upon said first sheet in plan view. The first and second pathways may be superposed in a manner such that the pathways are not exactly superposed one upon the other for a substantial part of their length, instead being offset or mis-aligned in plan view.
The offset may be a linear offset, or an angular offset, or both. In one preferred embodiment a first layer having a first track has a track with a general directionality extending in a first direction, and a second layer with a second track having a general directionality extending in a second, different, direction. The first and second layers may be adjacent to each other in the barrier, or they may not be adjacent.
The pathway may comprise a narrow wire or filament of electrically conductive material. Alternatively, the pathway may comprise a tape having a discernible width. The width of the tape may be about as wide as a typical, or minimum, gap between physically close portions of the track that are not linearly adjacent each other along the length of the track, the track preferably not touching itself in its meandering. The track is preferably a single continuous elongate electrical pathway.
There may be two, or more, side-by-side tracks which extend over the surface of a common carrier film generally parallel to each other but spaced apart.
There may be encapsulant material, under the barrier, between the barrier and the electronic component, and/or encapsulant material above the barrier. The barrier and electronic component may be encased in encapsulant. The encapsulant may comprise an epoxy material, for example a dark coloured epoxy.
There may be barrier sheet both above and below the electronic component.
The electronic component may comprise a PCB, and the barrier sheet may extend over a substantial part, or substantially the whole of, the PCB.
The module may include one or more sensors for sensing the detectable characteristics of one or more layers of the tamper-evident and/or tamper-resistant barrier, or the sensors may be outside of the module. Preferably the sensors are embedded in the encapsulant.
The sensor(s) may detect the presence or absence of a signal on a track. The sensor(s) may detect a voltage or current in a sheet element. Preferably the module includes a comparator adapted to compare a detected characteristic with an expected characteristic or with a reference. The comparator may be adapted to produce a marker or alarm signal if it detects an unacceptable comparison result.
Preferably the module includes a signal generator adapted to generate signals and to pass them through an input sheet element of at least one layer, and a detector detecting the output from an output adapted to detect whether the output of the output sheet element is as expected. The signals are preferably unpredictable in nature, so that an observer cannot predict what they will be. The signals may be random, pseudo random, or noise-like. The signal generator may be a noise generator or a pseudo random signal generator. The input and output sheet element could comprise the same sheet element, the detector detecting whether the signals input into the sheet element are coming out from it as expected. The detector could include a comparator to compare the input and output from a sheet element. The signal generator could produce a time varying signal, which may vary at a frequency of the order of thousands of Hz, or tens of thousands of Hz, or even higher.
The input sheet element and the output sheet element could be different sheet elements. For example, a signal could be input into one sheet element and transmitted to another sheet element if a gap between them is breached by a conductive tool during an attach on the module, or if a screen between them is broken.
Monitoring that a received signal is as expected does not necessarily mean monitoring that it is the same as what was input. The detected signal may be expected to be zero (e.g. twin-track electrical pathways with the signal in one track and not in the other, and detecting whether a bridging attack tool communicates the signal to the other track). The signal may be expected to suffer a predetermined change or degradation (e.g. attenuation, power loss, phase shift, etc, and the improvement of the signal beyond what is expected, or its over—degradation, may be indicative of tampering.
Another reason for having an element in the sheet into which a signal is injected or introduced is to hide any electromagnetic (e.m.) signals produced by the protected electronic component (e.g. a circuit board). There may be a masking emitter layer in the sheet adapted to emit electromagnetic radiation to mask the e.m. emissions of the protected electronic component. For example the power of the e.m. signals deliberately emitted by the masking layer could be significantly greater than that emitted by the protected electronic component. The power of e.m. radiation at the frequency range emitted by a protected electronic component (e.g. PCB) could be a factor of 2, 5, 10, 50, 100, 1000, 10000, or more less than the emissions emanating from the masking layer (active masking) when observed from outside the electronic component module. The masking emissions could be in the same general frequency range as those emitted by the protected electronic component. This may make it difficult for an external listener to differentiate the “real” e.m. signals from the electronic component of interest and those of the masking layer. The masking layer may generate noise, or noise-like signals, and/or it may generate a spoof signal which is intended to mask the true e.m. emissions of the electronic component of interest. The masking layer could comprise an antenna or emitter, for example a convoluted wire, for example having a free end and a signal-injection end communicated with a signal injector (e.g. on a PCB board).
It is preferred to have an e.m. shield layer, such as an earth plate layer, between an active e.m. emitter/masking layer and the electronic component. This is so that the electronic component does not suffer from interference from the masking e.m. emitter layer, and also to further attenuate e.m. signals from the electronic component.
It will be appreciated that the masking layer, which could be thought of as an active e.m. emitting layer, could comprise the same formations as a telltale trip wire. The same metal track could serve as both a trip wire with signals in it being maintained for proper transmission through the track, and it could also serve as an active e.m. emitter—a current in a wire does cause the emission of e.m. waves. The same signals in the wire could both cause the emission of electromagnetic waves to mask the spectrum being emitted by the protected electronic component and also be the signals that are checked to ensure that they are received as expected.
Instead of, or in addition to, having one or more sensors in the module itself, the module may have an extra-module communicator capable of communicating with an external monitor. For example the module may have an electrical connector connectable with an external sensor or processor. Alternatively it may have a wireless transmitter to communicate with an external device.
The barrier sheet may not have its layers bonded to each other. They could be separate layers, possibly free floating relative to each other. Encapsulant may conceivably be provided between two layers of the barrier sheet.
The module preferably has a power source, preferably encased in the encapsulant.
The module may have a sheet of frangible material.
The barrier sheet may have a central, main body portion extending in a general plane, but preferably not precisely in a single plane, and may have one or more side portions extending transversely away from the general main plane of the body portion to cover side regions of the electronic component. An upper barrier sheet may cover the upper plan surface area of the electronic component, and a lower barrier sheet may cover the lower plan surface area of the electronic component. Between them, the upper and lower barrier sheet may cover some or all of the sides of the electronic component, and may substantially enclose the electronic component in a container of barrier sheet. The container may comprise more than one separate barrier sheet or it may be a single sheet folded about the component.
The sheet of frangible material (if provided) may contact and overlie said encapsulant material and overlie said component, said sheet being sufficiently thin that it is likely to crack or break if an attempt is made to drill or cut through it with a laser drill. The frangible material may comprise a sheet of glass. The frangible material may have a thickness no thicker than about 1/10 of an inch, or no thicker than about 1/20 of an inch, or no thicker than about 1/100 of an inch. The sheet of frangible material may have a thickness of about 3/1000 of an inch thick, or less.
The sheet of frangible material may have a diffusive layer adapted in use to diffuse a laser beam so as to reduce the energy intensity of the light which passes through said sheet. The diffusive layer may comprise an etched surface of said sheet. The sheet may have a reflective layer adapted in use to reflect at least a substantial part of the light of an incident laser beam. The sheet of frangible material preferably has both a reflective layer adapted in use to reflect at least a substantial part of the light of an incident laser beam and a diffusive layer adapted in use to diffuse an incident laser beam so as to reduce the energy intensity of a beam which passes the diffusive layer, said reflective layer being disposed between said encapsulant material and said diffusive layer. Encapsulant is preferably sandwiched between two spaced apart said frangible sheets.
The electronic module may have the encapsulant containing said electronic component sandwiched between an upper and lower spaced apart sheets of glass with said encapsulant being in face to face contact with an inner face of each said sheet of glass, and at least one tamper-evident electronic element may be provided in said encapsulant material between said upper sheet and said electronic component and at least another tamper-evident electronic element is provided in said encapsulant material between said lower sheet and said electronic component. The upper and lower sheets of glass are preferably covered by a protective obscurant.
The encapsulant material includes chemical signature molecules.
The frangible sheet may be treated so as to cause it to be diffusive. It may be etched, ground or roughened.
According to a second aspect the invention comprises a multi-layer tamper-evident and/or tamper-resistant barrier sheet having a plurality of layers, and wherein said layers are selected from the group comprising: (i) an electromagnetic screen layer, preferably a continuous sheet or film of conductive material, such as metal:
(ii) a tell-tale trip wire layer; (iii) a tell-tale trip wire layer in which the trip wire meanders over the surface of the layer in a space-filling pattern; (iv) the layer (iii), with the pattern being a fractal pattern; (v) a multi-track layer having at least a first and second track spaced apart and extending generally parallel to each other and meandering as a pair over the surface of the multi-track layer. (vi) an active electromagnetic emission masking layer adapted in use to emit masking electromagnetic waves.
Preferably the barrier sheet comprises a unitary body, with its layers being bonded together, preferably over substantially their whole surface area. They may be glued or fused, e.g. heat-fused, together.
Preferably the barrier sheet is flexible, preferably flexible enough so as to be non-self supporting when held horizontally. It may be about as flexible as a sheet of standard A4 paper such as the US PTO prints its patents upon.
Preferably the barrier sheet has a contact tail which has electrically conductive formations adapted to contact each layers of the sheet with an appropriate electrical sensor.
The layers of the sheet preferably comprise insulating plastics material layers which carry conductive films or traces.
Each layer in the barrier sheet may have a thickness of about no more than 10 thousandth of an inch (or between. 1 and 100 thousandth of an inch).
The barrier sheet may have at least 3, 4, 5, or more layers, typically bound together.
Preferably the barrier sheet includes at least two of layers (i), and/or at least two layers from the group (ii), (iii), (iv) or (v). Preferably the sheet has an internal grouping of layer(s) at least one, and preferably at least two of layers (ii) to (v), sandwiched between two layers (i). The layers sandwiched between the layers of group (i) may be from the same one of groups (ii), (iii), (iv) or (v), or may be provided from more than one group.
The barrier sheet may have a foldable flap or flaps at the periphery of a main central, body portion adapted to cover side portions of an electronic component. The sheet may have a foldable lead tag adapted to fold under a main body portion of the sheet to provide a contact with the electronic component.
According to a third aspect the invention comprises a method of detecting tampering with an electronic component or of resisting tampering with an electronic component comprising protecting said component with an electrically or optically monitored barrier sheet, the barrier sheet having a plurality of tamper-evident and/or tamper-resistant layers which are monitored electronically or optically, and using different kinds of tamper-evident and/or tamper-resistant layer in the barrier sheet.
Preferably the barrier sheet is obscured from view, for example by encapsulating or encasing it and the electronic component in an encapsulant. The sheet may be flexible.
The method may include shielding inner tamper-evident and/or tamper-resistant layers of the barrier sheet from electromagnetic radiation by covering them with a layer of em shielding material, such as a substantially continuous film of metal. The two outermost layers of the barrier sheet (or a spaced pair of layers) may comprise the shielding layers.
The barrier sheet may have its layers imprecisely orientated with respect to each other. They may be linearly offset and/or angularity mis-aligned.
According to another aspect the invention comprises a method of making a tamper-evident and/or tamper-resistant electronic module comprising hiding a least one tamper-evident sheet in a body of encapsulant matrix material so that it overlies an electronic component also hidden in the body, and arranging for the precise position of the sheet in the body to be variable from module to module by one or more of:
(i) imprecisely holding said sheet and said electronic component whilst introducing fluid settable encapsulant material, (ii) introducing imprecise amounts of fluid settable encapsulant material between at least one of said components and said sheet, and/or said sheet and a body-surface defining mould; (iii) providing a by-pass flow passageway from at least one of: (a) the space between said electronic components and said sheet; and (b) the space between said sheet and a body-surface defining mould; thereby enabling the volume of encapsulant that exists in space (a) and/or space (b) to be variable and imprecisely controlled.
The tamper-evident and/or tamper-resistant sheet may have a hole or passageway through it for the flow of encapsulant material during manufacture of the body. The tamper-evident and/or tamper-resistant sheet may be a sheet in accordance with an earlier aspect of the invention.
There may be more than one sheet provided.
When the sheet is flexible this also provides a variable sheet-other structure space since the flexing of the sheet can take-up/accommodate variations in the amount of encapsulant above and/or below it.
The method may comprise folding portions of the sheet to cover side portions of the electronic component.
One or more of said sheet elements may comprise a substantially continuous layer of metal, possibly a film of metal. This may be an electromagnetic wave filter adapted to screen the passage of electromagnetic waves. Said continuous layer of metal may be arranged to carry a current when breached, for example if a metal tool contacts said continuous metal layer with an electrical current source.
Said detectable characteristic may comprise the current in, or the voltage of, said layer.
DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, of which:
FIG. 1 shows a tamper-evident and/or tamper-resistant electronic data storage or data providing device in accordance with the invention;
FIG. 2 shows the device of FIG. 1 , in this example in the form of a PCI card, or card-equivalent, being introduced into a PC;
FIG. 3 shows schematically a PCB protected using the present invention;
FIGS. 4A and 4B show part of FIG. 3 in more detail, FIG. 4A being an exploded view of FIG. 4B ;
FIGS. 5 to 11 show different layers and sheets for use in the invention;
FIG. 12A shows the unpredictable variation in precise alignment of different sheets;
FIG. 12B shows another sheet for use in the invention;
FIG. 13 shows a schematic exploded view of one preferred embodiment of the invention;
FIGS. 14A to 14C show a detail of how a sheet may be connected electronically to a power supply and/or sensors;
FIGS. 15A to 15C show schematically further detail of an embodiment of the invention;
FIGS. 16 to 18 show schematically another preferred embodiment of the invention;
FIG. 19 shows schematically a PCB suitable for protection in using the invention; and
FIG. 20 shows schematically a way of making the embodiment of the invention, and apparatus for making the embodiments.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a Trusted Clock PCI card 10 for a computer, such as a personal computer 12 shown in FIG. 2 . The card 10 is a half-width PCI card having a plurality of connectors 14 projecting from a glass-clad polymer matrix body 16 .
The card 10 is about 6 inches×4 inches×½″. It has a printed circuit board which carries electronic components such as clock-associated microprocessors a battery and assault sensors. The card 10 also has a thin glass upper sheet and a thin glass lower sheet. The glass of the upper and lower sheets is untoughened stressed glass which cracks or shatters when subjected to too much stress or strain. The glass sheets are in this example about 3/1000 of an inch thick and face the polymer matrix body 16 , with the glass and polymer matrix in intimate face-to-face contact. The body 16 is made of a black epoxy polymer material such as may be commonly used in the electronics industry as an adhesive for electronic components. The matrix material of the body carries a chemical marker or signature: a substance present, often added specifically, to aid recognition of the matrix material in tests. More than one chemical marker may be present in the matrix material.
The PCB may also carry a digital signer chip or have a chips which can provide a digital signature function.
In use of the card 10 the computer 12 sends via the connectors 14 a digest, hash, or fingerprint of a document to be timestamped to the card 10 , (which document may itself be a hash or digest of a larger document) and the clock chips of the card associate a time derived from their clock function with the document, and the digital signer (if provided) signs the timestamped document digest. The signed timestamped document digest, or hash, may be stored on a memory chip (not shown) on the PCB, and/or may be output back to the PC via the connectors 14 , preferably after first being encrypted.
The clock of the PCI 10 cannot be altered either (i) at all, or (ii) by unauthorised instructions. The PCI is tamper-evident because of its thin glass sheets, and also because of electrical/electromagnetic tamper-evident features to be described later. If the veracity of the timestamp applied to documents by the PCI 10 is to be established a trusted person, who may be the supplier of the PCI card, physically inspects the card for signs of tampering.
One way of tampering with a PCB or PCI card is to drill into the PCI card and interfere with the circuitry and/or chips on the card. Drills which could be used include mechanical drills, laser beams, and ion beams.
As mentioned above, electronic tamper-evident features are also provided. FIG. 3 shows the printed circuit described above, referenced 30 . The PCB 30 is protected by two flexible multi-layer sheets 32 and 34 . In this example each of the sheets 32 , 34 has four layers 36 , 38 , 40 and 42 , as shown in FIGS. 4A and 4B . Each of the layers 36 – 42 is a layer of flexible plastics polymer material, e.g. Mylar, printed with an electronic security measure, as will be described. The four layers of each sheet are bonded together. For example they may be fixed together by heat, or bonded using an adhesive. They are joined over substantially the whole of their face-to-face contact.
In a variant they are not bonded together as such, but do overlie each other. They may not be joined to each other directly, or they be joined at less than their whole face to face contact: e.g. they could be spot-bonded at regions and unbonded at other regions.
FIG. 5 shows layers 36 and 38 schematically. Layer 36 has substantially its whole surface area of one face, face 44 , coated with a continuous layer or film of copper 46 . Layer 38 also has one face, face 48 , coated with a continuous layer or film of copper 50 . The Mylar material of the layers is, of course, an electrical insulator. The copper film layers 46 and 50 effectively form a pair of metal plates spaced apart by the thickness of the Mylar layer 36 . Layers 36 and 38 each have a respective lead formation 52 and 54 which provide an electrical connection for the copper films 46 and 50 to earth and to a low level voltage source, e.g. 5V DC, respectively. The leads comprise continuous extensions of the layers 36 and 38 . The leads may be superposed, or they may exit the stack of layers at different positions.
FIG. 5 illustrates the operation of layers 36 and 38 . A sensor detects when there is any current flowing between the two plates, and/or any change in voltage. Whilst the layers 36 and 38 remain unattached there is no current flowing between them. If a conductive member (e.g. metal drill or knife) pierces the outer layer 36 and touches the inner layer 38 it will form a bridge between the two electrically conductive copper films 46 and 50 , and current will flow. This makes the attack detectable. The grounded plate 46 need not be earthed: it could be at a floating potential. Connecting the two plates 46 and 50 would still cause a current to flow/voltage to change: would still cause a detectable change or effect.
If the result of detecting an attack is that the protected electronic component is deactivated and does not produce the output that used to be a trusted output, then the sheet would provide a tamper-resistant effect; it would resist attempts (as well as evidence them) to subvert the electronic component by causing the component to cease its activity, thereby resisting the output of a subverted, non-trustworthy, output from the component.
Another benefit of having a sheet of metal, such as sheet or film 46 or 50 , is that it blocks the transmission of electromagnetic waves. The metal films 46 and 50 deposited on sheets 36 and 38 filter out e.m. transmissions both out from the PCB shielded by them, and e.m. transmissions directed in to the PCB. Thus e.m. leakage from the PCB is reduced by the films 46 and 50 , which makes it harder for an attacker to listen passively to the e.m. emissions of the PCB in order to try to deduce what it is doing, its structure, and how to attack it.
Furthermore, it is harder for an attacker to direct pulses of e.m. radiation, e.g. microwave, at the PCB in order to look at how the PCB reacts, again with a view to learning information to use in attacking the PCB.
Furthermore, it also makes it harder for an attacker to X-ray the PCI card 10 to determine structural information. It is difficult to get depth information out of X-ray pictures, and having one or more sheets of metal will achieve some observation of features in X-ray. It will be appreciated that the Faraday Cage e.m. screening effect and X-ray blocking effect can be achieved by a single sheet of metal, but that having two sheets gives a better effect, and the spaced different potential sheets can be used to detect punctures with a conductive article as well.
A continuous film of copper, or other conductive metal or material, is preferred because there are no gaps. It is known to enclose electronic components in a metal mesh cage to screen out e.m. transmissions. However high frequency waves can still get through the holes in a mesh. A continuous sheet does not have this problem.
FIGS. 4A and 4B also show layer 40 . Layer 40 comprises another flexible sheet of Mylar having on its upper surface a meandering “trip wire” or tell-tale 56 . The trip wire 56 is a printed track, trace or film of metal deposited onto the surface of the layer 40 . The arrangement is best illustrated in FIG. 6 . A voltage is applied, in use, to the trip wire 52 by a trip-integrity verifier module 58 which checks that the voltage detected in the trip wire 56 is the expected voltage. In one example a constant DC voltage, say, 5V, is applied to the trip 56 . If an attacker breaks the trip wire 56 the voltage will not be as expected and the fact that an attack has taken place can be established.
A typical metal track width could be about 3/1000 of an inch, or about 6/1000 of an inch, and these figures could be typical inter-track distances as well.
In a more sophisticated variant the module 58 sends a rapidly changing known, but unpredictable signal down the trip wire 54 and compares whether the signal that is received matches that which was emitted (with possible expected losses), and if it is not what is expected this is an indication of tampering. The approach makes it much harder for an attacker to clamp the wire to a fixed voltage either side of a portion of the wire to be broken to try to create a bridge past a break point. Even if an attacker tries to connect a bridge to transmit the fluctuating signals, instead of clamping to a fixed voltage, they will still have problems since the fluctuating signal is unpredictable (e.g. random, pseudo-random, or noise-like). This is especially so if the module 58 monitors parameters such as the time between data points in the emitted and detected signals, the time of flight of the emitted signal (longer lengths of wire, i.e. a bridge, would take longer to be traversed), for example phase differences can be used to check for a longer wire; the resistance and/or impedance of the trip wire (bridging a portion prior to breaking the bridged portion would probably alter the resistance and/or impedance), or the loss in the signal (a bridge is likely to alter the losses in received signal).
FIG. 6 shows only a small portion of the total surface area of the Mylar sheet 40 covered by the metal trace that is the wire 54 . This is schematic and in practice whilst a thin wire such as is drawn with relatively wide gaps between adjacent spaced portions of the wire a ratio of about ½ of the surface covered with wire material and ½ of the surface as “gaps” between the wire may be preferred. It may be preferred to deposit a narrow metal tape which has a significant width but is still thin enough to be broken (break transmission of signals) in the event of a drill attack. It is preferred that the width of the trip wire be about as wide as the spacing 60 of one part of the trip wire from another generally parallel portion of the trip wire adjacent the one portion. The width of the wire/track may be about 6/1000 of an inch, as may be the spacing between adjacent convolutions of the wire.
Layer 42 is very similar to layer 40 , except that its meandering trip wire, referred 62 , has its main elongate orientation direction at a different angle to that of layer 40 . As shown in FIG. 7 the conductive paths of the trips wires 54 and 62 are crossed, in this example substantially at right angles. The effect of superposing two crossed meanderline trip wire traces is to create, effectively, a grid of trip wires. An attacker trying to drill or pierce the sheet 32 has to try to avoid the grid of trip wires.
FIG. 8 shows the trip wire trace 54 more accurately. About half of the surface area of the layer 40 is covered with metal track and about half is uncoated (the pattern of course extends over substantially the whole area of the layer (or at least that part of the layer that overlies the PCB).
FIG. 9 a shows another pattern of metal/conducting deposits on a flexible sheet (e.g. Mylar). This time there are relatively wide block 64 of metal with gaps 66 that are narrower than the metal. The metal blocks 64 may be at different electrical potentials and a metal drill could bridge them, shorting them. Having wide bands instead of narrow tracks makes it less likely that a drill will completely sever a track, and completely interrupt a signal being transmitted via the track, but it makes it more likely that the drill will contact a band and not be wholly in a space between bands. It is then necessary to notice that there is not the same track as before. One possibility is that interfering with the area covered by a track may alter its capacitance, or may alter its ability to carry a standing wave, or may alter its natural resonant frequency, or may degrade the signal it carries. Detecting these changes may result in detecting an attack. Once an attack is detected this fact could be used in tamper-evident mode (e.g. reporting the attack) or tamper-resistant mode (e.g. shutting down the protected electronic component).
FIG. 10 shows another modification for a possible layer in a protective sheet. In this example two trip wires 68 and 70 are provided, with wire 68 following a convoluted meandering path on the surface of Mylar sheet 72 , and with trip wire 70 following the path of wire 68 but spaced a distance from it.
The two wires 68 and 70 are at different base voltages and carry modulated signals (possibly with different modulation patterns or sequences). If one wire is broken the loss of the correct modulation/the loss of one modulated signal is detected. If a conductive member (e.g. metal drill) contacts both wires it can cause a short circuit between the wires (because they are at different voltages) and this can be detected.
A problem with regular repeating patterns for the trip wires 54 and 62 is that an attacker may be able to predict where the gaps between trip wires are located: where they can drill in without breaking a trip wire. One solution is to have more layers of trip wires so as to fill in the plan projected area with trip wires, so that no, or substantially no straight through line large enough for a drill exists. One approach to this is to have a third trip wire layer. This may have its axial direction at a different direction to the other trip wires, say at 45° to the main direction of the wires in the layers 40 and 42 . Further trip wire layers may be provided, possibly with the direction of the trip wires extending either (i) in a different direction to the wire of other layers, or (ii) with the trip wire miss-aligned with another layer/other layers so that the trip wires are not exactly superposed. FIG. 9B shows this. In solid line is one layer of wires or tape 74 , and in dotted line a linearly shifted additional layer of similar wires or tape 76 . It is an effective way of obtaining good projected area cover with relatively few layers. 100%, or effectively 100% cover of projected plan area could be achieved using only two layers, but 3 layers may give added security.
Another answer to the problem of being able to predict where gaps in the trip wire coverage occur is to have the trip wire have a non-regular path. FIG. 11 shows alternative embodiment protective Mylar sheet 80 having two layers: a first layer 82 and a second layer 84 . The first layer has a winding, meandering, convoluted track 86 of metal printed on it. The track is shown schematically and is a space-filling fractal pattern 88 , in this example of the Peano family of space-filling curves. About half of the surface area of the sheet 80 is overlaid with metal track, and about half of the surface area is track-free (and serves to keep portions of the track separate and insulated from each other).
It will be noted that the fractal pattern 88 has a general path direction, shown as dotted line 90 in FIG. 11 , and that this too wanders over the area of the sheet 82 to fill it. Arrow 92 shows the general linear direction of the pattern.
Layer 84 also has another trip wire track 94 which follows a Peano space filling curve, not exactly the same as that of layer 82 , but broadly similar. It too has a general direction 96 which in this example is aligned at about 45° to that of layer 82 .
Even if an attacker has engineering drawings of the protective sheet 80 it is still difficult to find a straight through drill line which will not break or touch a trip wire.
FIG. 12 illustrates another refinement, with the effect exaggerated for clarity. Three sheets 100 , 102 , 104 , each carrying a wiggling, meandering trip wire track are to be bonded into a single composite multi-layers sheet. The sheets are roughly aligned so that the physical size and shape of the composite sheet is more or less standard, or standard but with significant tolerances, and the sheets 100 , 102 and 104 are then bonded together.
Because the alignment of the three sheets 100 – 104 is not precise, and because the tracks are of the order of a few thousandth of an inch wide, there is great variation between different manufactured composite multi-layered sheets as to where exactly all of the tracks are disposed, and their relative positions. Hand assembly can facilitate this degree of deliberate imprecision, but a machine can be instructed to achieve a similar effect. In this way, perhaps even the manufacturer does not know where the trip wire tracks are with any precision reliable enough to drill into an electronic component protected by the sheet with any certainty of not hitting a wire.
FIG. 12B shows another feature. Sheet 400 comprises a Mylar sheet with a metal antenna 402 printed upon it. A signal injection end 404 of the antenna 402 is connectable to a signal injector device (not shown). A masking signal is input into the antenna during use of the device, the masking signal producing electromagnetic emissions that hide the electromagnetic emissions of a protected electronic component. The e.m. signals from the antenna 402 may be more powerful than those from the protected electronic component (e.g. PCB). They may be in the same general frequency range (or at least overlap the frequency of the e.m. signals emitted by the protected electronic component).
The antenna may emit noise, or a random or pseudo random signal. It may emit a spoof signal which may be taken by an attacker to provide information about the activities of the protected electronic component. It may emit a spoof signal buried in, but extractable from, a background (e.g. noise).
FIG. 12B also shows earth plane sheet 406 , similar to sheet 36 , between the sheet 400 and the protected electronic component, referenced 408 (and shown schematically). This may be to protect the component from the e.m. signals emitted by the masking layer sheet 400 , and/or further hide the signals from the electronic component.
FIG. 13 illustrates a preferred embodiment of the invention. A PCB 110 is encapsulated in a solid epoxy encapsulant 112 which is sandwiched between two Mylar sheets 114 and 116 . Further epoxy encapsulant 118 surrounds the Mylar sheet/PCB sandwich. Each of the Mylar sheets 114 and 116 is a flexible bonded multi-layer sheet having an outer ground layer 120 similar to layer 36 of FIG. 5 , a meandering space-filling fractal wire layer 122 similar to that of layer 82 of FIG. 11 , and another meandering space-filling fractal wire layer 124 similar to that of layer 84 of FIG. 11 , but with its main direction 96 at about right angles to the main direction 92 , of the layer 122 .
If a metal probe (e.g. drill) bridges the track 86 on layer 82 / 122 and the ground plate 120 this can be detected since it will effectively amount to closing a switch on a detection circuit. If either trip wire 86 or 94 is broken the digital signals sent down them, which in this example change tens of thousands of times a second, are not received as expected, which sets off a tamper alarm.
FIGS. 14A to 14C illustrate schematically a feature of a multi-layer Mylar sheet 130 . As will be understood, the layers in the sheet 130 which rely upon electronic detection of changes in electrical or electronic parameters or characteristics need to be in communication with appropriate sensors and signal processors. The sheet 130 has a lead or tail 132 provided to do this. Because the sheet is flexible the tail can simply be bent over to contact a PCB board 134 . As shown in FIG. 14B , the tail 132 can be bent under the main body of the sheet 130 to contact the PCB 134 at a position 136 that is under the sheet, and that is therefore protected by the sheet.
FIG. 14C shows that the different layers, referenced 138 , 140 , 142 of the sheet could in the region of the tail stop at different points so as to expose contact regions of the tail to provide spaced contact points 144 , 146 , 148 for the printed metallic layers on each layer 138 , 140 , 142 .
FIGS. 15A to 15C show another refinement. PCB's (and many other electronic components) have a finite thickness and have edge surfaces 150 which could be attacked by an attacker. The flexible protective sheeting 152 is shaped with fold-down flaps 154 , 156 , 158 , 160 which can be bent during manufacture of a protected device. The flaps 154 to 160 are bent or folded down to cover the sides 150 of the PCB. FIG. 15C shows two protective flexible sheets 152 and 162 each of which is shaped into a box-like structure similar to that shown in FIG. 15B , and one box is then nested inside the other fully to surround the PCB.
Of course, instead of effectively having a box made of two separate sheets, the flexible protective sheets could be joined and be a single sheet. The PCB or other device to be protected could be held inside an envelope, pouch, or bag of flexible protective sheet.
FIG. 16 to 18 show another embodiment of the invention. A PCB 110 is surrounded by black epoxy resin encapsulant 112 . A multi-layer flexible Mylar sheet 114 is provided beneath the PCB, and another 116 above it. The sheets 114 and 116 are as described in relation to FIG. 13 . Further black epoxy encapsulant 118 overlays the sheets 114 and 116 . A lower and upper sheet of thin glass 160 and 162 are in contact with the encapsulant 118 , and still further black epoxy encapsulant 164 overlies the glass sheets 160 and 162 .
The sheets of glass 160 and 162 are about 3/1000 of an inch thick and are made of untoughend glass which shatters or cracks easily when stressed.
The outer surface 166 of the glass 160 , 162 is a diffusive surface, such as an etched surface, and diffuses in use a laser beam to reduce the spatial energy intensity of light transmitted past the diffusive surface. The inner surface 168 of the glass, 160 , 162 , the one nearer to the PCB, is mirrored: coated with a reflective material. This is to reflect a laser beam that is incident upon it.
FIG. 17 shows another feature of the invention. The microchips and other electronic components mounted on the board 110 are schematically represented in chain dotted outline and are referenced 170 . They have a depth and project away from the board 110 itself. The flexible multi-layer Mylar sheet 116 is shown having a non-flat, contoured surface. The sheet 116 forms valleys between projecting electronic components 170 and hills over the components 170 . This means that the surface of the sheet 116 is not all in the same plane, and the sheets of electronically conductive trip wires 86 and 94 , and the ground planes 46 are also not in any one plane. This can make it difficult to X-ray or otherwise image the conductive electronic tell-tale layers to know where the tamper-evident structures are provided. It also makes it difficult to know where they are working from plans.
Of course, the flexible electronic counter-intrusion sheets 114 , 116 could be provided outside of the glass sheets 160 , 162 , instead of, or as well as, inside them.
FIG. 18 shows side or end plates 172 of thin glass, similar to the top and bottom sheets 162 and 160 , and shows that a glass clad module 174 is encased in the encapsulant 164 to form a block 176 .
FIG. 19 shows details of an alternative PCB board 190 to be protected in accordance with the invention. The board 190 has a Trusted Clock chip 192 , a battery 194 , board interference sensors 196 , 197 , 198 , a signal injector 199 , a PIC chip 200 and an output only line 210 . There are no external inputs to the PCB 190 : it simply sends out a timestamp signal via line 210 . It may do this periodically, e.g. once every second, or every minute, or for example, every 1/100 of a second. Alternatively there may be an input to the chip 210 , referenced 212 , for example in order to correct its clock for drift.
Sensor 196 is a temperature sensor, such as a thermister. This senses the temperature at the chip and either provides that to the PIC chip 200 which determines whether it is within allowable bands, or compares the signal from sensor 196 with a reference temperature signal and checks that they are close enough, within an allowable range. This can detect overheating (e.g. due to laser attack), or cooling (e.g. sub zero ° C. cooling). Sensor 197 is a vibration sensor and/or orientation sensor (possibly an electronic gyroscope) which sends signals to the chip 192 which checks if untoward vibration and/or re-orientating of the PCB has taken place. Sensor 128 is a power supply sensor which senses the power supply to the chip 192 and/or chip 200 and provides signals indicative of power supply characteristics to the chip 200 which uses them, possibly in combination with a reference power supply signal, to determine whether the power supply to chip 192 and/or itself is being altered or perturbed. Signal injector 199 generates known signals of known characteristics, and introduces them to parts of the PCB. Those known generated signals are fed back to the chip 200 where a comparator compares the injected signals with the returned signals and if the match is not what was expected this is indicative of a problem, and that the Trusted Clock may have been compromised and is unsafe. The injected signals may constitute guard signals transmitted over a guard network or guard wire where breaking the wire (e.g. with a drill) blocks the transmission of the guard signals. Alternatively or additionally the injected signals may be injected into the chip 192 itself and may be influenced by attacks on the clip 192 . The injected, or guard, signals may be a fluctuating signal which changes rapidly in a known way. For example it may be a digital signal that is altered thousands of times a second.
It will be appreciated that upon detection of a non-allowable event the chip 200 may instruct the Trusted Clock chip 192 not to produce any more time signals, and/or it may emit an alarm signal, and/or it may note the event in an internal memory, a memory on the PCB, or an external memory (or it may record the event in more than one memory). The alarm signal may be transmitted via output 210 , or possibly via a wireless alarm emitter provided on the PCB 190 .
It will be appreciated that the inputs to the chip 200 will also include a sensor sensing whether a signal has been detected from a sensing element on a flexible protection layer of an overlaying protective sheet, similar to sheet 114 or 116 . For example, the signal injector 129 provides signals to the meandering trip wire layers 82 and 84 of the flexible sheeting, and a sensor senses whether any current flows to the grounding layer 46 of the sheeting. The PCB board will typically have sheets such as sheets 114 and 116 both above it and below it.
To produce the module 174 of FIG. 18 the sheets of glass and the sheets of flexible protective plastics with embedded circuitry, and the PCB are held in place with their relative positions established and the epoxy polymer material 112 and 118 (which comprises the same black epoxy) is injected between the PCB and the Mylar sheets 114 , 116 and between the Mylar sheets the glass plates, and also around the glass plates. The epoxy then sets.
When forming the module 174 there may be tamper-evident sheet support surfaces, or plates, provided to support the tamper-evident sheet (e.g. thin glass sheet) laterally as the epoxy or other encapsulant is introduced between the electronic component and the tamper-evident sheet. The support surface and the tamper-evident sheet may be in face-to-face contact as the encapsulant is injected/introduced. This enables thinner sheets of glass or other tamper-evident material to be used than would otherwise be the case since they do not have to withstand the lateral forces applied by the encapsulant unaided. The support surfaces may remain in contact with the face of the tamper-evident sheet whilst the epoxy/encapsulant beneath the sheet cures (this can also cause stress/strain in the sheet). The temperature of the module 174 and the support surfaces may be controlled during curing of the encapsulant, for example to avoid too-rapid cooling which may put too great a strain on the thin tamper-evident sheet: in order to avoid thermal shock from breaking the tamper-evident sheet.
FIG. 20 shows schematically a manufacturing apparatus 299 comprising positioning rig 300 , epoxy dispense nozzles 302 , an epoxy dispense system 304 , a positioning rig control system 306 , and a control processor 308 . The control processor controls the movement and operation of the positioning rig 300 and the epoxy dispense system 204 . Mould walls 310 are used to define the outer surfaces of the block 176 of encapsulant that surrounds the module, as seen in FIG. 18 .
It may be necessary to form the module 174 of FIG. 18 first, before encapsulating that module with epoxy to create the block 176 of FIG. 18 .
The dispense nozzles 202 may be movable. There may be some dispense nozzles which are used to form the module 174 , and some that are used to introduce the material of the encapsulant that forms the outer positions of the bock 176 , portions referenced 178 in FIG. 18 .
FIG. 20 shows a possible advantageous feature. One or more of the glass or flexible sheets may have a through hole or holes 312 extending through them which allow epoxy under pressure to pass through. This may help to key the Mylar sheet, or glass plate, to the body of epoxy that is beneath it.
It also alleviates the need to be too precise in the amount of epoxy that is pumped in, and the flow rate of epoxy, since the hole(s) effectively provide an overflow escape route for excess epoxy. FIG. 20 shows schematically at 314 such flowed-through epoxy which effectively become patches of epoxy on the outer side of the glass sheets (or Mylar sheets if they are holed). Walls 310 may have such epoxy-escape channels.
Alternatively another excess epoxy escape channel mechanism may be provided to remove the need to control the volume and rheological properties of the epoxy too closely.
The glass plates and/or the Mylar sheets may be held relatively imprecisely in position, possibly with a degree of movement in their position. This may be used to accommodate encapsulant-injection problems.
It will be appreciated that the PCB may be exposed to conditions before its in-situ use in an electronic device, when the electronic device is itself in its final phase of use, which would be outside of the parameters set for triggering an attack alarm. For example if a device is left in an unheated warehouse it could get as cold as −20° C., and a device may be vibrated and re-orientated during transport. For this reason the PCB, or the PIC chip, could have an activation trigger which can be activated when the device is ready for use, after unusual installation conditions have already occurred.
It will also be appreciated that one business model for using the invention is that a Trusted Organisation (someone who is likely to be believed) may allow a customer, person or company to take possession of one of their Trusted Clock Modules on condition that they do not tamper with it, and the customer uses the Trusted Clock Module to timestamp documents. Periodically (e.g. once every year or every 6 months) the Trusted Organisation may inspect the Trusted Clock Module for signs of tampering and if no sign is found the data or documents timestamped by that Trusted Clock Module in the foregoing period can be trusted to have the correct timestamp. If the Trusted Clock Module is found to have a sign consistent with tampering then the timestamps that it has made since it was last checked may be suspect. Some action may be taken against a customer who has permitted their module to be tampered with, or some warning given to them.
Of course, the Trusted Clock Module could be inspected or investigated for signs of tampering at any time: it is not necessary to wait for the predetermined pre-planned inspection times. Indeed, there may be no pre-scheduled inspection timetable: the module could simply be checked for tampering by a Trusted Person/the Trusted Organisation upon demand.
It will also be appreciated that a network, such as a LAN or WAN, could share a Trusted Clock Module without needing Internet access to it.
It will be appreciated that the Mylar layers of a multi-layer sheet should be thick enough to support the metal tracks or formations deposited on them, and thick enough to insulate electrically one layer of metal formations from another layer of metal formations. | A tamper evident electronic module comprises an electronic component, a tamper evident sheet, and encapsulant material. Said component is encapsulated in the encapsulant material and the sheet overlies the component, and the sheet comprises a flexible multi-layer sheet, a plurality of the layers of the sheet being selected from the group below:
(i) an electromagnetic radiation shield layer; (ii) a tell-tale electrically conductive trip wire defining a convoluted meandering pathway on the layer, the trip wire meandering in a pattern which substantially covers the electronic component in a space filled area if the layer; (iii) a layer having the features of (ii), and in which the pathway comprises a fractual pattern; (iv) a layer having the features of (ii), and in which a second tell-tale trip wire extends alongside a first tell-tale trip wire so that they meander as a spaced pair. (v) an active electromagnetic marking layer adapted to emitt electromagnetic radiation. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to two co-pending U.S. patent applications, which are: application Ser. No. 13/242,011, application Ser. No. 13/242,006, and all entitled “DRAINAGE DEVICE FOR CLOSED CHAMBER CONTAINING LIQUID”. In this co-pending applications, the inventors are Yang et al. Such co-pending applications have the same assignee as the present application. The disclosure of the above two identified applications are incorporated herein by reference.
BACKGROUND
1. Technical Field
The present disclosure generally relates to drainage devices, and particularly, to a drainage device for draining liquid out of a closed chamber.
2. Description of the Related Art
In the discharge of sewage, sewage is generally sucked into a container to be purified by a water suction cleaner, and then discharged outside. The sewage suction cleaner includes a closed chamber and an air pump. The air pump creates a certain degree of vacuum in the closed chamber. Under the negative air pressure, the sewage is pushed into the closed chamber. However, when discharging the sewage, outside air will flow into the closed chamber via an outlet, and thus the degree of vacuum of the closed chamber is decreased. As a result, the air pressure difference between the inside and the outside of the closed chamber is decreased, and sewage is not forced as strongly into the closed chamber.
Therefore, there is room for improvement within the art.
BRIEF DESCRIPTION OF THE DRAWING
The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a sectional view of an embodiment of a drainage device in a first state.
FIG. 2 is a sectional view of the drainage device of FIG. 1 in the first state with a receiving chamber full of liquid.
FIG. 3 is a sectional view of the drainage device of FIG. 1 in a second state.
DETAILED DESCRIPTION
Referring to FIG. 1 , an embodiment of a drainage device 100 includes an air cylinder 20 , a driving assembly 30 , a first sealing assembly 40 , a second sealing assembly 50 , and a controller 60 .
A closed chamber 10 defines a fluid channel 12 and a gas channel 14 in the top end, and a slag discharge hole 16 in the bottom end of the closed chamber 10 . The closed chamber 10 further includes a sealing cover 18 for sealing the slag discharge hole 16 . The fluid channel 12 is used for liquid flow, and is equipped with a flow control valve (not shown). The gas channel 14 is connected to an air pump (not shown) for producing a certain degree of vacuum in the closed chamber 10 .
The air cylinder 20 is positioned in the closed chamber 10 , and includes a main body 21 , an action piston 23 positioned in the main body 21 , and a connecting rod 25 connected to the action piston 23 , a first channel 217 , and a second channel 219 opposite to the first channel 217 . The main body 21 is substantially cylindrical, and defines a receiving chamber 211 . One end of the main body 21 defines a liquid inlet 213 and a liquid outlet 215 communicating with the receiving chamber 211 , and the other end of the main body 21 is hermetically sealed. The liquid inlet 213 is opposite to the liquid outlet 215 . The first channel 217 communicates with the liquid inlet 213 , and the second channel 219 communicates with the liquid outlet 215 . The first channel 217 is below the level of the liquid of the closed chamber 10 . The liquid in the receiving chamber 211 may be discharged outside the closed chamber 10 via the second channel 219 .
The action piston 23 is movably received in the receiving chamber 211 , and forms a sealing surface 231 against a sidewall 2111 of the main body 21 , and a resisting surface 233 adjacent to the liquid inlet 213 . The action piston 23 separates or segregates the receiving chamber 211 into a first chamber 2113 and a second chamber 2115 . The first chamber 2113 communicates with the liquid inlet 213 and the liquid outlet 215 . The action piston 23 is fixed to the bottom of the connecting rod 25 , which extends through the top end of the main body 21 .
The driving assembly 30 includes a receiving body 31 , a drive piston 33 movably received in the receiving body 31 , and a drive rod 35 . The receiving body 31 is positioned on the outer surface of the closed chamber 10 . The drive rod 35 connects the drive piston 33 to the connecting rod 25 .
The first sealing assembly 40 is positioned in the first channel 217 , and includes a fixed piston 41 , a flexible member 43 , and a filter 45 . The flexible member 43 and the filter 45 are positioned on opposite sides of the fixed piston 41 , and the flexible member 43 is closer to the liquid inlet 213 . The fixed piston 41 defines a plurality of permeable holes (not shown), so that any liquid in the closed chamber 10 can flow to the receiving chamber 211 via the permeable holes. The flexible member 43 is attached to the inner surface of the first channel 217 in order to seal the first channel 217 . In the illustrated embodiment, the flexible member 43 is a circular silicone mat, and the filter 45 is a metal mesh filter, and functions as a large-scale filter of the liquid flowing into the receiving chamber 211 .
The second sealing assembly 50 is positioned in the second channel 219 , and includes a fixed piston 51 and a flexible member 53 . The fixed piston 51 has a similar structure and function to those of the fixed piston 41 . The flexible member 53 has a similar structure and function to those of the flexible member 43 .
The controller 60 includes a sensor 61 positioned beneath the surface of the liquid in the closed chamber 10 . The controller 60 monitors the level of any liquid in the closed chamber 10 by means of the sensor 61 and controls the movements of the driving assembly 30 .
In assembly of the drainage device 100 , the air cylinder 20 is positioned in the closed chamber 10 , with the liquid inlet 213 and the liquid outlet 215 being immersed in the liquid of the closed chamber 10 . The first sealing assembly 40 is positioned in the first channel 217 , and the second sealing assembly 50 is positioned in the second channel 219 . The fixed piston 41 is fixed to the inner surface of the first channel 217 . The flexible member 43 is fixed to the liquid inlet 213 -side of the fixed piston 41 . The filter 45 is positioned in the first channel 217 and away from the flexible member 43 . The fixed piston 51 is fixed to the inner surface of the second channel 219 . The flexible member 53 is fixed away from the liquid outlet 215 -side of the fixed piston 51 .
The driving assembly 30 is fixed on the outer surface of the closed chamber 10 . The drive rod 35 connects the drive piston 33 to the connecting rod 25 . The controller 60 is positioned in the closed chamber 10 .
Referring to FIGS. 1 and 2 , in use, the closed chamber 10 is subjected to a predetermined degree of vacuum via the air pump, and liquid is sucked into the closed chamber 10 via the fluid channel 12 . When the liquid level in the closed chamber 10 exceeds a predetermined level, the sensor 61 generates a signal. The controller 60 transmits a start signal to the driving assembly 30 , and then the driving assembly 30 starts to work. The drive rod 35 drives the connecting rod 25 to move upwards. As a result, the action piston 23 slides in the receiving chamber 211 away from the liquid inlet 213 , and as the volume of the first chamber 2113 is increased, the air pressure in the first chamber 2113 is reduced. The air pressure difference between the first chamber 2113 and the closed chamber 10 causes the liquid in the closed chamber 10 to move through the filter 45 and the fixed piston 41 , and to be sucked into the first chamber 2113 because of the negative air pressure. This is the drainage device 100 in the first state.
When the action piston 23 has moved the maximum distance upward relative to the liquid inlet 213 , the first chamber 2113 is filled with liquid as shown in FIG. 2 . Referring to FIG. 3 , after the first chamber 2113 is filled with liquid, the drive rod 35 drives the connecting rod 25 to move downwards. As a result, the action piston 23 slides in the receiving chamber 211 towards the liquid inlet 213 , thereby reducing the volume of the first chamber 2113 and thus increasing the pressure. Under pressure, the liquid in the first chamber 2113 is forced through or around the flexible member 53 and into the second channel 219 , the flexible member 43 is pressed tightly against the fixed piston 41 by means of the applied pressure. This is the drainage device 100 in the second state, in which the liquid in the first chamber 2113 is being discharged to the outside via the second channel 219 .
As the drainage device 100 continuously operates between the first state and the second state, the liquid in the closed chamber 10 is drained to the outside. When the liquid level in the closed chamber 10 again falls to the predetermined level, the sensor 61 detects it and generates a closing signal. The controller 60 transmits the closing signal to the driving assembly 30 , and then the drainage device 100 stops. In addition, if there is sediment which has accumulated at the bottom of the closed chamber 10 , the sealing cover 18 can be opened to remove the sediment from the closed chamber 10 . It should be pointed out that, the connecting rod 25 and the drive rod 35 can be integrally formed.
When the liquid of the closed chamber 10 flows into the first chamber 2113 via the first channel 217 , the flexible member 53 seals the second channel 219 . When the liquid of the first chamber 2113 flows to the outside via the second channel 219 , the flexible member 43 seals the first channel 217 . Therefore, the outside air cannot reach the inside of the closed chamber 10 at any time.
While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims. | A drainage device for draining liquid out of a closed chamber includes an air cylinder, a driving assembly, a first channel, a second channel, a first sealing assembly, a second sealing assembly, and a controller. The air cylinder includes a main body defining a receiving chamber, an action piston positioned in the receiving chamber of the main body, and a connecting rod connected to the action piston. The main body defines a liquid inlet and a liquid outlet, both of which communicate with the receiving chamber, and the presence of a fixed piston with a seal in each of the inlet and outlet creates a double-acting one-way valve when the action piston is moved up and down. | 5 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to containers for products, and more particularly relates to retort containers for food.
[0002] Retort containers are containers that are hermetically sealed after filling with a food product, and are then heated to a temperature of about 100° C. to 120° C. for a period of time to ensure that all microorganisms in the container have been killed. The chief advantages of retort containers is that they do not require refrigeration prior to opening, and they can be stored for long periods of time in their initially sealed condition. For many years, metal cans were the predominant type of retort container.
[0003] More recently, plastic retort containers have been developed. Plastic containers are attractive for various reasons, including microwavability. One of the challenges with plastic retort containers is the closure system. More particularly, the container lid must be hermetically sealed to the container with sufficient strength to withstand the elevated temperature and pressure conditions during retort sterilization; on the other hand, the seal strength must not be so high that the consumer finds it difficult or impossible to remove the lid. Retort integrity and ease of opening are usually at odds with each other, such that anything that is done to improve retort integrity has a deleterious effect on ease of opening, and vice versa.
[0004] Prior to the present invention, plastic retort containers have generally included some type of membrane lid that is heat-sealed to the container. The difficulties of accurately controlling the seal strength of heat seals are well known. For instance, some heat seal materials such as SURLYN® (ionomer resin) have a relatively narrow heat sealing temperature window within which the resulting seal strength is in a desirable range. If the sealing temperature is too low, the seal strength may be inadequate to prevent failure during retort; if the temperature is too high, the seal strength may be so great that the consumer cannot remove the lid. It can be difficult to control the sealing temperature with sufficient accuracy to stay within the desired window.
[0005] Other requirements for all-plastic retort containers and lids include high-barrier performance against water vapor and oxygen, and fast sealing speed. The high-barrier performance must be achieved without the use of metal foil, which has commonly been used in many retort containers. Fast sealing speed is difficult to achieve with all-plastic lids because induction sealing cannot be used, and direct thermal heat sealing is slow because of the poor thermal conductivity of plastic.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention addresses the above needs and achieves other advantages, by providing an all-plastic retort container wherein the lid is adhesively sealed to the container as opposed to being heat-sealed to the container. The adhesive employed for sealing the lid to the container is specially formulated to provide a temperature-dependent bond, such that at room temperature the bond strength is relatively low, while at retort temperatures of 100° C. to 120° C. the bond strength is higher.
[0007] In one embodiment of the invention, a retort container comprises a container body structured and arranged for holding a food product, the container body defining an opening and a sealing surface surrounding the opening, and a lid bonded to the sealing surface of the container body to close the opening, the lid being bonded to the sealing surface with a hot melt adhesive. The adhesive comprises a polyamide resin blended with a second resin that raises the glass transition temperature of the adhesive above the glass transition temperature of the polyamide resin alone, the adhesive bonding the lid to the sealing surface with a temperature-dependent bond strength that is relatively low at room temperature and substantially higher at retort temperatures of 100° C. to 120° C.
[0008] The hot melt adhesive preferably has a glass transition temperature (T g ) close to room temperature, for example about 20° C. to 40° C. A preferred adhesive comprises a substantially amorphous polyamide resin as a primary component. The polyamide resin can have a T g that is less than or equal to 0° C. An example of a suitable polyamide resin is UNI-REZ® 2617 available from Arizona Chemical of Jacksonville, Fla. A second resin is added to the polyamide resin in sufficient amount to raise the T g of the resulting composition to about room temperature. The second resin can comprise a maleic modified rosin ester. An example of a suitable second resin is a maleic modified glycerine ester of tall oil rosin such as SYLVACOTE® 7071 available from Arizona Chemical of Jacksonville, Fla.
[0009] As an example, the adhesive can comprise a polyamide resin and a maleic modified rosin ester, wherein the maleic modified rosin ester comprises about 10 to about 20 weight percent of the adhesive.
[0010] The invention is applicable to a wide range of container types and configurations. As one example, the container body can be thermoformed from an all-plastic high-barrier sheet. The sheet can have a structure, for example, of {polypropylene/tie/EVOH/tie/polypropylene}. The polypropylene layers are good barriers against moisture, while the ethylene vinyl alcohol copolymer (EVOH) layer provides oxygen barrier performance. The sheet can be formed by coextrusion or other processes.
[0011] Alternatively, the container body can be formed by a coextrusion blow-molding process. For example, a parison can be coextruded as a multi-layer structure such as {polypropylene/tie/EVOH/tie/polypropylene} and then enclosed in a mold and inflated to form the container body.
[0012] The lid similarly can comprise a multi-layer structure such as {polypropylene/tie/EVOH/tie/polypropylene}. Other high-barrier multi-layer structures can be used for the container body and/or lid.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0013] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0014] FIG. 1 is a schematic cross-sectional view of a thermoformed container in accordance with one embodiment of the invention;
[0015] FIG. 2 is a schematic fragmentary cross-sectional view of the container of FIG. 1 illustrating on an enlarged scale the lid sealed to the container body to show the multi-layer structures of the lid and container body, and the hot melt adhesive therebetween;
[0016] FIG. 3 is a schematic cross-sectional view of a blow-molded container in accordance with another embodiment of the invention;
[0017] FIG. 4 is a schematic fragmentary cross-sectional view of a container in accordance with yet another embodiment of the invention having a metal ring and membrane lid closure; and
[0018] FIG. 5 is a schematic fragmentary cross-sectional view of the container of FIG. 4 illustrating on an enlarged scale the lid sealed to the metal ring to show the multi-layer structures of the lid and the hot melt adhesive for sealing the lid to the ring.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
[0020] FIG. 1 illustrates a first embodiment of the invention as applied to a plastic thermoformed container 10 . The container 10 comprises a container body 12 and a lid 14 . The container body 12 is formed by thermoforming a multi-layer high-barrier sheet. The container body 12 has a bottom wall 16 , and an upstanding side wall 18 that preferably flares (i.e., gets larger in diameter) in the upward direction for ease of removal of the container body from the mold (not shown). At the upper end of the side wall 18 a radially extending flange 20 is formed as an extension of the side wall. The flange provides a sealing surface to which the lid 14 is sealed.
[0021] With reference to FIG. 2 , the multi-layer high-barrier sheet that forms the container body can comprise, for example, a first layer 22 forming the inner surface of the container and hence the upper surface of the flange 20 , a second layer 24 , and a third layer 26 , wherein the second layer 24 is disposed between the first layer 22 and the third layer 26 . Tie layers 23 , 25 can be included between the first and second layers and between the second and third layers, respectively, for binding the layers together. The first layer 22 can comprise a polypropylene, which is a good barrier against moisture but is not particularly effective against oxygen. The second layer 24 can be an ethylene vinyl alcohol copolymer (EVOH), which has good oxygen barrier properties but is deleteriously affected by exposure to moisture. The third layer 26 can comprise a polypropylene. Thus, the polypropylene layers provide moisture barrier performance and protect the EVOH layer from exposure to moisture, and the EVOH layer provides oxygen barrier performance. Various other structures can be used for the multi-layer sheet from which the container body 12 is formed, the invention not being limited to any particular structure.
[0022] FIG. 2 also shows that the lid 14 can comprise a multi-layer structure similar to that of the container body. Thus, the illustrated lid has a first layer 28 , a second layer 30 and a third layer 32 , which can be joined together with tie layers 29 , 31 if necessary or desirable. The first and third layers can comprise a polypropylene, and the second layer can comprise EVOH. Alternative lid constructions can be used, the invention not being limited to any particular lid structure.
[0023] The lid 14 is bonded to the flange 20 of the container body by a hot melt adhesive 40 . The adhesive 40 is formulated to provide a temperature-dependent bond strength between the lid 14 and the container body 12 . More specifically, the bond strength is relatively low at room temperature so that the lid can be readily peeled from the container body, while the bond strength is higher at retort temperatures of about 100° C. to 120° C. The adhesive preferably comprises a substantially amorphous polyamide-based composition having a glass transition temperature, T g , that is approximately room temperature (e.g., 20° C. to 40° C.). When amorphous polymers are near their glass transition temperature, they tend to lose their adhesiveness. Accordingly, by engineering the adhesive 40 so that its T g is near room temperature, the bond strength provided by the adhesive is relatively low at room temperature. However, at retort temperatures, which are substantially above T g , the adhesive has greater adhesiveness and hence provides a stronger bond. In this manner, the lid can be bonded to the container body firmly enough to withstand retort without failure, and yet the lid can easily be peeled off when the consumer desires to open the container.
[0024] A suitable adhesive 40 can comprise a polyamide resin having a T g that is less than or equal to 0° C., and a second resin that raises the T g of the adhesive to about room temperature. The polyamide resin can be, for example, the resin available from Arizona Chemical of Jacksonville, Fla., having the designation UNI-REZ® 2617. This resin has a tensile modulus of 205 MPa (30,000 psi), a softening point (ASTM E 28 ring and ball method) of 163° C. to 175° C., and a shear adhesion failure temperature or SAFT (ASTM D 4498 method with a 1 kg. weight) of 150° C.
[0025] The second resin can be a maleic modified rosin ester. An example of a suitable material is SYLVACOTE® 7071 available from Arizona Chemical. This material is a maleic modified glycerine ester of tall oil rosin, and its recommended applications include as a film-forming resin for nitrocellulose-based packaging-gravure inks that contain acetone, and in lacquer wood furniture sealer and sander coats. It has a softening point (ASTM E 28-67 ring and ball method) of 125° C.
[0026] The T g -raising resin is added to the polyamide resin in sufficient quantity to raise the T g of the resulting composition to about room temperature. The composition can also contain other components as desired. As an example, the adhesive composition can comprise about 70 to 95 weight percent, more preferably about 80 to 90 weight percent, of polyamide resin, and about 30 to 5 weight percent, more preferably about 20 to 10 weight percent, of maleic modified rosin ester.
[0027] The adhesive should have a shear adhesion failure temperature (SAFT) above the expected temperature of retort, which is typically between about 100° C. and about 120° C. While the addition of the maleic modified rosin ester to the polyamide resin, which on its own has an SAFT of about 150° C., is likely to bring the SAFT of the composition down somewhat below 150° C., it should still be above 120° C.
[0028] As noted, the invention is not limited to any particular container type or configuration. Thus, FIG. 3 shows an alternative container 110 having a container body 112 that is formed by coextrusion blow molding. The container body includes a flange 120 to which the lid 114 is bonded by a hot melt adhesive as previously described. The container body is formed by coextruding a parison as a multi-layer structure, enclosing the parison in a mold, inserting a blow pin into the parison, and inflating the parison to fill the mold. As known in the art, blow molding allows the manufacture of container shapes that cannot be made by thermoforming, which is generally limited to tapered shapes that can be lifted out of the open top end of the mold. In contrast, the molds used in blow molding are formed in left and right halves such that the mold is opened by moving the mold halves apart, and hence molded articles of non-tapered and other shapes can be made, such as illustrated in FIG. 3 . The container body wall can have a multi-layer structure similar to that illustrated in FIG. 2 , or can have alternative structures.
[0029] FIGS. 4 and 5 illustrate yet another type of container 210 to which the invention is applicable. The container includes a container body 212 , which can be of various materials and constructions including those described above or others, and a metal ring 250 that is affixed to the upper end of the container body. The ring is affixed to the container body by double-seaming, wherein a curled outer edge portion 252 of the ring and a curled top edge portion 213 of the container body are rolled together to provide a hermetic joint therebetween. The ring includes an annular portion 254 that extends radially inwardly from the container body wall and terminates at a radially inner edge 256 , which can be curled as shown. The upper surface of the annular portion 254 constitutes a sealing surface to which the lid 214 of the container is sealed by a hot melt adhesive 240 .
[0030] The lid 214 can have various constructions. The exemplary construction shown in FIG. 5 includes a first layer 228 , a tie layer 229 , a second layer 230 , a tie layer 231 , and a third layer 232 . The first and third layers can comprise polypropylene, and the second layer can comprise EVOH. In the various embodiments described above, materials other than those listed above can be used. For instance, instead of the maleic modified glycerine ester of tall oil rosin, the adhesive can employ other T g -raising materials. Furthermore, while container body and lid structures have been described that include a barrier structure of the type {polypropylene/tie/EVOH/tie/polypropylene}, other structures can be used. For instance, the barrier structure can include aluminum oxide-coated polymer film, SiOx-coated polymer film, metallized film, polyacrylonitrile, and others.
[0031] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A retort container comprises a container body structured and arranged for holding a food product, the container body defining an opening and a sealing surface surrounding the opening, and a lid bonded to the sealing surface of the container body to close the opening, the lid being bonded to the sealing surface with a hot melt adhesive. The adhesive comprises a polyamide resin blended with a second resin that raises the glass transition temperature of the adhesive above the glass transition temperature of the polyamide resin alone, the adhesive bonding the lid to the sealing surface with a temperature-dependent bond strength that is relatively low at room temperature and substantially higher at retort temperatures of 100° C. to 120° C. | 2 |
FIELD OF INVENTION
[0001] The present invention generally relates to an ear strap for assisting arrangement of a probe tube in the ear canal. The present invention more particularly relates an ear strap that can be used to fix a probe tube in the ear canal, adjust its position in the ear canal and be attached to and be detached from the probe tube in a fast and simple way.
DESCRIPTION OF RELATED ART
[0002] A variety of hearing aids have been developed to correct the hearing of users having different degrees of hearing impairments. In many situations an individual adjusting of the hearing aid is required in order to make the hearing aid work optimal.
[0003] Such adjusting is in particular important for children and people with a high degree of hearing impairment. However, these types of adjustments are also carried out in other types of users, depending on the individual sales or delivery office tradition. The adjusting is based on a so-called “real-ear measurement”, where the sound pressure inside the ear canal in front of the eardrum is measured while the patient is wearing the hearing aid.
[0004] Usually the “real-ear measurement” is carried out by the dispenser while the patient has a so-called “plug” in the ear canal. The plug is normally moulded to fit the outermost portion of the ear canal. The receiver is either provided in the plug, or placed in the hearing aid. In the latter the receiver is connected to the area in front of the eardrum by means of a tube extending through a channel in the plug.
[0005] The measurement is carried out by providing a small tube adjacent to the earplug and hereby providing an acoustic connection between the space between the plug and the eardrum and a microphone connected to the opposite end of the tube. When the receiver generates a given sound, it is possible to measure the sound pressure generated in front of the eardrum.
[0006] It is known to apply different types of strips in order to maintain e.g. an ear piece or an ear plug in the right and desired position within the ear canal.
[0007] EP 1448014 B1 discloses a behind-the-ear (BTE) hearing aid that comprises an ear piece provided with a so-called “sports lock” keeping the ear piece in place. The “sports lock” is shaped as a flexible fibre attached directly to the ear piece or via the sound tube to the ear piece. The fibre is adapted to attribute the outer ear e.g. at the lower part of the concha.
[0008] U.S. Pat. No. 7,720,244 B2 discloses an ear piece for a hearing aid that comprises a plug connected to a housing via a tube. The earpiece comprises a contact element for resting against an inside of the user's tragus and/or the ear canal and a fixture having means for adjusting the spacing between the plug and the contact element.
[0009] US 2007 183615 A1 discloses an ear canal device and a retaining strip. The ear canal device has a part configured to be inserted into the ear canal. The retaining strip is fastened to the ear canal device at its first end. The retaining strip is configured to be arranged to lie resiliently against the inside of the concha.
[0010] US 2009 092269 A1 discloses a hearing aid having a flexible elongated member with a first end attached to a shell and a second free end. The flexible elongated member has a shape for stabilizing the shell relative to a user's ear.
[0011] WO 2004 73349 A2 discloses a hearing aid system comprising a receiver configured to be inserted into the ear canal of a user. The hearing aid system comprises a connection portion extending between a sound processing component connection and the receiver. The system comprises a retaining wire configured to be positioned within a portion of the concha of the ear.
[0012] During a “real-ear measurement” it is important that the probe tube is placed and maintained at the right position. The probe tube has to be arranged so deep in the ear canal that interference from the reflected sound from the eardrum can be avoided. On the other hand the probe tube may not be place to near to the eardrum since this can potentially damage the eardrum. When the probe tube has been placed correctly at the optimal position by the dispenser, the dispenser has to hold the probe tube fixed in this position until the ear mould or hearing aid is in place. This is a major drawback and none of the prior art systems provides a solution to this challenge.
[0013] Thus, there is a need for an improved ear strap for a probe tube, which ear strap can be used to provide and maintain a probe tube in the right position within the ear canal.
[0014] The present invention provides an ear strap that can be used to provide and maintain a probe tube in the right position within the ear canal.
[0015] Moreover, the invention also provides an ear strap that can be attached to the concha of the ear and ensure that the probe tube maintains its correct position in the ear canal.
SUMMARY OF THE INVENTION
[0016] The invention can be achieved by an ear strap as defined in claim 1 . Preferred embodiments are defined in the dependent sub claims and explained in the following description and illustrated in the accompanying drawings.
[0017] The ear strap according to the invention is an ear strap comprising attachment means for being attached to a tube, where the ear strap has a flexible member configured to be placed within the concha of the ear and to be held in place by the concha of the ear, where the flexible member is configured to take a form that fits the shape of the concha of the ear. The ear strap comprises means for adjusting the position of the tube relative to the attachment means.
[0018] Here it is achieved that the ear strap can be used to provide and maintain a probe tube in the right position within the ear canal when a “real-ear measurement” has to be carried out. The ear strap can be attached to the concha of the ear and hereby it can be ensured that the probe tube maintains its correct position in the ear canal.
[0019] By the term “being attached to a tube” means that the attachment means is configured to be attached to a tube in a manner in which the attachment means and the tube are maintained fixed relative to each other.
[0020] The flexible member is configured to be placed within the concha of the ear and to be held in place by the concha of the ear. This means that the flexible member can be maintained in a position in which the flexible member is fixed to the concha of the ear. Bending of the flexible member provides a tension large enough to keep the flexible member fixed to the concha of the ear. Accordingly, the flexible member both takes a form that fits the shape of the concha of the ear and provides a mechanical attachment to the concha of the ear.
[0021] In an embodiment, the attachment means comprises an opening for receiving a tube and that the means for adjusting the position of the tube relative to the attachment means are configured to increase the size of the opening and hereby allow for attachment of the attachment means to the tube and for detachment of the attachment means from the tube.
[0022] Hereby the attachment means makes it possible to attach the attachment means to a tube and to detach the attachment means from a tube in a fast and easy manner.
[0023] In an embodiment, the means for adjusting the position of the tube relative to the attachment means is a pull out string being attached to the attachment means, where the pull out string is configured to transfer a force applied to the pull out string to the tube and hereby change the position of the tube relative to the attachment means.
[0024] Hereby it is achieved that the position of the tube relative to the attachment means can be changed and adjusted in an easy and secure way. This is useful when the ear strap is used to provide and maintain a probe tube in the right position within the ear canal when a “real-ear measurement” has to be carried out. Even when the ear strap has been attached to the concha of the ear, the position of the probe tube in the ear canal can be adjusted if desired.
[0025] In an embodiment, the pull out string is rod shaped and configured to be handled by just one or two fingers.
[0026] It may be beneficial that the attachment means is configured to be attached to a tube in such a way that the position of the tube relative to the attachment means can be changed when a force exceeding a predefined level is applied to the pull out string and that the tube is moved without changing the position of the tube relative to the attachment means when a smaller force is applied to the pull out string. In this way it is possible to use the pull out string to move the probe tube (when a small force is applied) e.g. in order to maintain the right position of the probe tube within the ear. When a larger force is applied, the position of the tube relative to the attachment means is changed (it may require that the tube is maintained in a fixed position e.g. by a hand).
[0027] In praxis the position of the tube relative to the attachment means can be changed when the applied force exceeds the retention force that is defined by the coefficient of static friction between the contact surface of the attachment means and the tube. As long as the applied force is smaller than the retention force, the attachment means will be maintained attached to the tube in the same position of attachment.
[0028] It may be beneficial that the pull out string protrudes from the attachment means and that the pull out string is rod shaped. Hereby it becomes easier to get hold of and handle the pull out string.
[0029] In an embodiment, a knob member is provided at the distal end of the pull out string. Hereby the use of the pull out string is eased. Moreover it becomes easier to get hold of and handle the pull out string.
[0030] The knob member may be spherical or have any other suitable geometrical shape.
[0031] It may be beneficial that that an aperture is provided in the attachment means.
[0032] Hereby the flexibility of the attachment means is increased so that attachment of a tube (e.g. a tube having a bend) is eased. The aperture may also make it easier to detach the tube from the attachment means.
[0033] In an embodiment, the attachment means comprises at least one pair of corresponding protruding locking members that are configured to maintain a tube attached to the attachment means once the tube has been attached to the attachment means.
[0034] Hereby a secure and reliable way of maintaining a tube attached to the attachment means can be provided. The locking members are preferably configured to allow an easy detachment of the tube from the attachment means by moving the locking members away from each other. Hereby a simple mechanical locking mechanism can be provided.
[0035] It may be beneficial that the attachment means comprises a semi cylindrical section configured to receive and bear against a tube and that the attachment means comprises a number of abutting plane sections extending basically perpendicular to the longitudinal axis of the semi cylindrical section or the attachment means.
[0036] Hereby the attachment means can be attached to a tube without damaging the tube. The tube may bear against the semi cylindrical section and at the same time be protected from damage by the structure of the semi cylindrical section. The semi cylindrical section may be provided with a surface structure or a surface layer in order to achieve any desired coefficients of friction between the tube and the contact surface of the semi cylindrical section.
[0037] In an embodiment, the opening is defined by the plane sections and the locking members. It may be beneficial that the opening has its smallest width at the region between the locking members so that the space between the locking members determines if a tube may be attached to the attachment means. It may be preferred that the locking members are configured in such a manner that the tube increases the space between the locking members the moment they pass the locking members while being inserted into the semi cylindrical section.
[0038] It may be beneficial that the attachment means comprises a body that is arranged symmetrically about the longitudinal axis of the attachment means. Hereby it is achieved that a probe tube may be attached to the attachment means regardless to the orientation of the attachment means.
[0039] It may be beneficial that the flexible member is conical so that the distal end of the flexible member has a smaller width than the proximal end of the flexible member.
[0040] Hereby the required flexibility (great flexibility of the distal end of the flexible member) and strength (great strength in the proximal end of the flexible member) of the flexible member can be provided.
[0041] In an embodiment, the longitudinal axis of the attachment means extends basically perpendicular to the longitudinal axis of the flexible member.
[0042] It may beneficial that the attachment means and the pull out string are arranged in such a way that the angle between the longitudinal axis of the attachment means and the longitudinal axis of the pull out string is smaller than 45 degrees, preferably smaller than 30 degrees.
[0043] In an embodiment, the attachment means in one end is attached at the proximal end of the flexible member and that an arm member is attached to the opposite end of the attachment means and that a pull out string is attached to the arm member. Hereby a reliable and simple ear strap can be provided.
[0044] It is preferred that the attachment means is configured to be attached to a probe tube for performing a “real-ear measurement”, where the sound pressure inside the ear canal in front of the eardrum is measured while a patient is wearing a hearing aid such as a BTE hearing aid device or a receiver-in-the-ear (RITE) hearing aid device.
[0045] It may be useful to have a kit comprising an ear strap according to one of the claims and a probe tube for performing a “real-ear measurement”. Such a kit may be used to carry out reliable and safe “real-ear measurement”.
DESCRIPTION OF THE DRAWINGS
[0046] The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:
[0047] FIG. 1A ) shows an ear strap attached to a probe tube that is arranged in the ear canal of a client according to an embodiment of the invention;
[0048] FIG. 1B ) shows the ear strap shown in FIG. 1A ) attached to maintain a probe tube extending adjacent to an earplug in a desired position in the ear canal according to an embodiment of the invention;
[0049] FIG. 2A ) shows a first perspective view of an ear strap according to the invention, FIG. 2B ) shows a second perspective view of the ear strap according to an embodiment of the invention, and FIG. 2C ) shows a third perspective view of the ear strap according to an embodiment of the invention;
[0050] FIG. 3A ) shows a first perspective close-up view of the attachment member of the ear strap illustrated in FIG. 2 according to an embodiment of the invention, and FIG. 3B ) shows a second perspective close-up view of the attachment member of the ear strap illustrated in FIG. 2 according to an embodiment of the invention;
[0051] FIG. 4 shows another close-up view of the attachment member of the ear strap illustrated in FIGS. 2 and 3 according to an embodiment of the invention; and
[0052] FIG. 5 shows yet another perspective close-up view of the attachment member of the ear strap illustrated in FIGS. 2-4 according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0053] Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, different views of an ear strap 2 according to the invention is illustrated in FIG. 1 .
[0054] FIG. 1A ) illustrates an ear strap 2 according to the invention attached to a probe tube 4 that has been inserted into the ear canal 20 of a client. The ear 16 is seen from the side and the ear canal 20 is illustrated as an open canal for illustration purposes.
[0055] A microphone 14 is attached to the end of the probe tube 4 . The ear strap 2 is attached to the probe tube 4 by means of an attachment member 6 (see FIG. 3-5 for a close-up view). The ear strap 2 comprises a flexible strap member 3 that is attached to the concha 18 . The flexible strap member 3 (also just called a flexible member 3 ) is configured to take a form that fits the shape of the concha 18 . The ear strap 2 moreover comprises a pull out string 8 configured to be used to adjust the position of the probe tube 4 in the ear canal 20 and to pull out the probe tube 4 from the ear canal 20 . A spherical knob 10 is provided at the distal end of the pull out string 8 . This knob 10 makes it easier to get hold of and use the pull out string 8 .
[0056] FIG. 1B ) also illustrates the ear strap 2 shown in FIG. 1A ). The ear strap 2 is attached to maintain a probe tube 4 that extends adjacent to an earplug 24 (that has been inserted into the ear canal 20 ) in a desired position in the ear canal 20 . The probe tube 4 is connected to a hearing aid device 22 . The hearing aid device 22 is a BTE hearing aid device 22 that has been attached behind the ear 16 and is connected to the earplug 24 by means of a connection tube 26 .
[0057] The ear strap 2 comprises a flexible strap member 3 that extends along the outside surface of the earplug 24 and is attached to the concha 18 . Due to its flexibility the flexible strap member 3 has taken a form that fits the shape of the concha 18 .
[0058] The ear strap 2 is provided with a pull out string 8 that is intended to be used to adjust the position of the probe tube 4 and be used to pull out the probe tube 4 from the ear canal 20 . Like in FIG. 1A ) a spherical knob 10 is provided at the distal end of the pull out string 8 .
[0059] When the BTE hearing aid device 22 has to be adjusted a “real-ear measurement” can be carried out by detecting the sound pressure inside the ear canal 20 in front of the eardrum (not shown) while the patient is wearing the hearing aid device 22 like illustrated in FIG. 1B ).
[0060] The dispenser can carry out the “real-ear measurement” while the patient has the earplug 24 inserted in the ear canal 20 like shown in FIG. 1B ). The earplug 24 is moulded to fit the outermost portion of the ear canal 20 .
[0061] The “real-ear measurement” is carried out by providing small probe tube 4 adjacent to the earplug 24 and hereby providing an acoustic connection between the space between the earplug 24 and the eardrum (not shown) and a microphone connected to the opposite end of the probe tube 4 .
[0062] FIGS. 2A ), 2 B) and 2 C) illustrates three perspective views of an ear strap 2 according to an embodiment of the invention. The ear strap 2 comprises an elongated strap member 3 having a distal end 38 and a proximal end 36 . An attachment member 6 is provided at the proximal end 36 of the strap member 3 . The attachment member 6 is configured to be attached to a probe tube (see FIG. 1A ) and FIG. 1B )) in order to control the position of the probe tube.
[0063] The probe tube is intended to be attached to the attachment member 6 of the ear strap 2 by insertion of the probe tube through the opening 40 . An aperture 28 is provided in the attachment member 6 for giving the required flexibility. Moreover the aperture 28 may be used when the probe tube has to be detached from the attachment member 6 of the ear strap 2 .
[0064] The ear strap 2 is provided with a pull out string 8 that is intended to be used to adjust the position of a probe tube 4 and to be used to pull out the probe tube 4 from the ear canal like illustrated in FIG. 1 . The pull out string 8 is attached to an arm member 12 that is attached to the attachment member 6 . A spherical knob 10 is provided at the distal end of the pull out string 8 .
[0065] The strap member 3 is conical and is having its greatest width at the proximal end 36 of the strap member 3 and its smallest width at the distal end 38 of the strap member 3 . Hereby the required flexibility and strength of the strap member 3 can be provided.
[0066] The strap member 3 extends along its longitudinal axis X and the longitudinal axis Y of the attachment member 6 extends basically perpendicular to the longitudinal axis X of the strap member 3 . The pull out string 8 is formed as a thin rod having a longitudinal axis Z. The angle 8 between the longitudinal axis Y of the attachment member 6 and the longitudinal axis Z of the pull out string 8 is about 20 degrees. It is possible to provide an ear strap 2 in which the pull out string 8 is arranged differently in order to achieve a smaller angle θ between the longitudinal axis Y of the attachment member 6 and the longitudinal axis Z of the pull out string 8 , e.g. an angle θ of 0, 5, 10 or 15 degrees. The angle θ between the longitudinal axis Y of the attachment member 6 and the longitudinal axis Z of the pull out string 8 may also be larger than shown in FIG. 2B ), e.g. 25, 30, 35 or 40 degrees by way of example.
[0067] FIG. 3 illustrates two perspective close-up views of the attachment member 6 of the ear strap 2 illustrated in FIG. 1 and FIG. 2 . It can be seen that the attachment member 6 is attached at the proximal end 36 of the strap member 3 of the ear strap 2 .
[0068] The attachment member 6 has a body comprising a semi cylindrical section 32 and plane sections 34 . An opening 40 extends along the longitudinal axis Y of the attachment member 6 .
[0069] An arm member 12 is provided at the distal end of the attachment member 6 and a pull out string 8 having a spherical knob 10 attached to its free end is attached to the arm member 12 .
[0070] An aperture 28 is provided in the central portion of the semi cylindrical section 32 .
[0071] Two locking members 30 are provided at the midsection of the attachment member 6 . The locking members 30 are basically wedge shaped and extend basically perpendicular to the longitudinal axis Y of the attachment member 6 . The locking members 30 are configured to secure a probe tube (see FIG. 1 ) within the attachment member 6 when the probe tube has been attached to the attachment member 6 .
[0072] Together with the semi cylindrical section 32 the inside surface of the locking members 30 constitutes a cylindrical portion configured to receive and bear against a probe tube. The attachment member 6 may be manufactured in a plastic, silicone or rubber material allowing the locking members 30 to be moved apart from each other in order to make it possible to insert a probe tube into the cylindrical portion through the opening 40 .
[0073] FIG. 4 illustrates another close-up view of the attachment member 6 of the ear strap 2 shown in FIG. 1-3 . The attachment member 6 is symmetrical about both the longitudinal axis X of the strap member 3 and about the longitudinal axis Y of the attachment member 6 . The arm member 12 , however, is not completely symmetric about the longitudinal axis X of the strap member 3 .
[0074] It can be seen that the angles α, α′, β, β′ between the plane sections 34 of the attachment member 6 and the longitudinal axis Y of the attachment member 6 is about 20 degrees. The angle e between the longitudinal axis Y of the attachment member 6 and the longitudinal axis Z of the pull out string 8 is also approximately 20 degrees.
[0075] FIG. 5 illustrates a close-up view of the attachment member 6 shown in FIG. 2-4 . It can be seen that the locking members 30 are protruding from the plane sections 34 of the attachment member 6 . Both the semi cylindrical sections 32 and the abutting plane sections 34 are smooth surfaces, however, it is possible to provide these surfaces with a structure in order to increase the friction between these surfaces and the probe tube (see FIG. 1 ) the attachment member 6 is configured to be attached to.
[0076] It can be seen that the pull out string 8 is integrated within the body of the attachment member 6 . Hereby the pull out string 8 may be used to detach a probe tube from the attachment member 6 simply by forcing the pull out string 8 in a direction away from the strap member 3 of the ear strap 2 .
[0077] It should be appreciated that reference throughout this specification to “one embodiment” or “an embodiment” or features included as “may” or “can” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” or features included as “may”/“can” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the invention.
[0078] Throughout the foregoing description, for the purposes of explanation, numerous specific details were set forth in order to provide a thorough understanding of the invention.
[0079] Accordingly, the scope of the invention should be judged in terms of the claims which follow.
List of Reference Numerals
[0080] 2 —Ear strap
[0081] 3 —Strap member
[0082] 4 —Probe tube
[0083] 6 —Attachment member
[0084] 8 —Pull out string
[0085] 10 —Knob
[0086] 12 —Arm member
[0087] 14 —Microphone
[0088] 16 —Ear
[0089] 18 —Concha
[0090] 20 —Ear canal
[0091] 22 —Hearing aid device
[0092] 24 —Plug
[0093] 26 —Connection
[0094] 28 —Aperture
[0095] 30 —Locking member
[0096] 32 —Semi cylindrical member
[0097] 34 —Plane section
[0098] 36 —Proximal end
[0099] 38 —Distal end
[0100] 40 —Opening
[0101] X—Axis
[0102] Y—Axis
[0103] Z—Axis
[0104] α, α′, β, β′, θ—Angle | An ear strap is disclosed. The ear strap comprises attachment means configured to be attached to a tube. The ear strap has a flexible member configured to be placed within the concha of the ear and to be held in place by the concha of the ear. The flexible member is configured to take a form that fits the shape of the concha of the ear. The ear strap comprises means for adjusting the position of the tube relative to the attachment means. | 0 |
[0001] The present invention claims foreign priority to Japanese application 2007-088805, filed on Mar. 29, 2007, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an optical DQPSK (Differential Quadrature Phase Shift Keying) receiver and a control method of abnormality detection in the optical DQPSK receiver.
DESCRIPTION OF THE RELATED ART
[0003] In optical communication systems where the transmission capacity thereof has been rapidly increasing, a binary amplitude shift keying (also called as OOK: On-Off Keying) is mainly used as a way of a modulation format, which includes NRZ (Non-Return-to-Zero) modulation format or RZ (Return-to-Zero) modulation format.
[0004] Recently, some other modulation/demodulation schemes have been utilized in optical communication systems, such as a Duo-Binary modulation, a CSRZ (Carrier-Suppressed Return-to-Zero) modulation, a DPSK (Differential Phase Shift Keying) modulation.
[0005] In the DPSK modulation, data is modulated to a phase shift between two symbols adjacent to each other. In a binary DPSK modulation which utilizes two phase shifts, the phase shifts are 0 or π. A DPSK modulation utilizing four phase shifts of 0, π/2, π, and 3π/2 is called as DQPSK (Differential Quadrature Phase Shift Keying) modulation.
[0006] Comparing with the conventional OOK modulation, DPSK modulation allows to improve an optical S/N ratio (OSNR: Optical Signal-to-Noise Ratio) by about 3 dB and to enhance an optical signal's resistance against nonlinear effects.
[0007] Since optical DQPSK utilizes a quaternary symbol, a spectral efficiency of the transmission is doubled to the OOK. That eases demands for speeds of electric devices, requirements for chromatic dispersion compensation, or requirements for polarization mode dispersion. Thus, optical DQPSK is a promising candidate of next generation optical communication systems.
[0008] A typical optical DQPSK receiver includes a set of Mach-Zehnder interferometers corresponding to an I-branch and Q-branch of DQPSK demodulation, as shown in “Optical Differential Quardrature Phase-Shift Key (ODQPSK) for High capacity Optical Transmission” by R. A. Griffin et al., Optical Fiber communication Conference and Exhibit, 2002. OFP2002 17-22 Mar. 2002 Pages 67-368. Each Mach-Zehnder interferometer includes an optical delay element τ which corresponds to a symbol time period in a transmission system.
[0009] The optical phase difference between the branches of an interferometer is set to be π/4 in the I-branch and −π/4 in the Q-branch. The two output terminals of each interferometer are connected to a balanced photo detector for regenerating transmitted data.
[0010] The configuration and operation of an optical DQPSK transmitter and receiver are also described in JP2004-516743 or WO2002/051041, for example.
[0011] FIG. 1 shows a configuration of a network of optical DQPSK using RZ format.
[0012] In FIG. 1 , a narrow-band optical transmitter 1 inputs 21.5 Gbps of data 1 and data 2 from a DQPSK precoder 100 and thereby inputs the data into phase-shift modulators 120 A, 120 B respectively.
[0013] The phase-shift modulator 120 A modulates a light from a light source 110 into a signal light with optical phases of 0 (rad) or π (rad), according to the data 1 . The phase-shift modulator 120 B delays the light from the light source 110 by π/2 (rad) and modulates it into a signal light with optical phases of π/2 (rad) or 3π/2 (rad), according to the data 2 .
[0014] Signal lights output from the phase-shift modulators 120 A and 120 B are multiplexed to a DQPSK signal of 43 Gbps and the DQPSK signal is modulated with RZ intensity-modulation at an intensity modulator 130 into a RZ-DQPSK modulated signal and transmitted onto a network (optical transmission line) 3 , as an optical phase modulated signal.
[0015] The optical signal output from the optical transmitter 1 propagates the optical transmission line (network) 3 , which comprises a WDM (Wavelength Division Multiplexing) network. The network 3 includes a WDM multiplexing (WDM MUX) circuit 4 , an optical amplifier AMP, and a demultiplexer 5 for WDM light, at some middle points.
[0016] The signal/noise ratio of the optical signal is degraded during amplification in the optical amplifier (AMP). Also, amount of chromatic dispersion of the optical signal increases in a long distance transmission by optical fiber. In order to compensate the chromatic dispersion, a dispersion compensator 6 is disposed in a fore-stage of the narrow-band optical receiver 2 .
[0017] The narrow-band optical receiver 2 includes delay interferometers 200 A and 200 B, photodetectors (TWIN-PD) 210 A and 210 B, equivalent amplifiers 211 A and 211 B, discrimination circuits (clock and data recovery circuits; CDR) 220 A and 220 B, decoder 230 , and an optical phase control circuit 240 . Input optical signal are branched to delay interferometer 200 A and 200 B. In the delay interferometers 200 A and 200 B, input signals are further branched to two and one of the branched optical signal is shifted by 1-bit earlier and interferes with the other branched optical signal, of which optical phase is delayed by π/4 (rad), or −π/4 (rad), respectively. In the balanced photo detectors (TWIN-PD) 210 A and 210 B, the optical phase modulated signals output from the delay interferometer 200 A and 200 B, respectively, are subjected to differential optical/electrical conversion and converted electrical signals are subjected to an equivalent amplification in the equivalent amplifier 211 A and 211 B, respectively.
[0018] In the CDR 220 A and 220 B, the electrical signals output from the equivalent amplifier are converted to an I-channel signal and a Q-channel signal, respectively, and the CDR 220 A and 220 B work as the data recovery circuit. In decoder 230 , the I-channel signal and the Q-channel signal are subjected to a bit swap logic inversion processing, which corresponds to the processing of the DQPSK precoder 100 in the optical transmitter 100 .
[0019] In the receiver 2 of FIG. 1 , it is important to keep the optical phase difference accurately at π/4 (rad) and −π/4 (rad) between the branches of the delay interferometer 200 A and 200 B, respectively. If the optical phase difference of the delay interferometer 200 A or 200 B becomes otherwise, waveform distortion of the output signal exceeds an allowable range. To keep the accurate optical phase difference, a feedback control is performed by an optical phase control circuit 240 .
[0020] The optical phase control circuit 240 monitors a phase error detected in the receiver 2 and generates a phase adjustment signal that adjusts the phase of the interferometers so that the phase differences are maintained at a target value.
[0021] A typical feedback control method is known as a dither-peak-detection method. In this method, the phase shift added to the optical signal is slightly fluctuated at a frequency f and signal component with frequency 2 f is monitored as an error signal. The 2 f component of the error signal become minimized when the phase at the interferometers are maintained at a target value.
[0022] When the dither-peak-detection method is used in the optical phase control circuit 240 for controlling the delay of optical phase to be π/4 (rad) or −π/4 (rad) at the delay interferometers 200 A and 200 B, respectively, following problems arise.
[0023] First, fluctuating the phase causes a degradation of waveform distortion of the optical end electrical signal.
[0024] Second, the peak detection (detection of the above described minimum value) only indicates whether or not the phase is adjusted to the target value and does not indicate whether the target phase is larger or smaller than the target value.
[0025] Third, since a relation between the peak level of the detection signal and the phase error generally varies in a quadratic curve, the sensitivity of the peak detection signal against the phase to be adjusted is reduced as the phase error approaches to zero.
[0026] Fourth, the speed of phase control is restricted by the fluctuation frequency (frequency f in the description above).
[0027] FIG. 2 shows a configuration of the optical DQPSK receiver of the embodiment, also described in a Japanese patent application of JP2005-305052, now published as JP2007-20138 (prior application). In FIG. 2 , one of the two branches, I-branch and Q-branch, is referred to as an A-branch, and the other is referred to as a B-branch.
[0028] In FIG. 2 , an input DQPSK signal (or RZ-DQPSK signal) is branched and directed to a delay interferometer 11 a in the A-branch and a delay interferometer 11 b in the B-branch.
[0029] In the delay interferometers 11 A and 11 B, input signals are further branched to two. The delay interferometers 11 a and 11 b include an optical delay element and a phase-shift element, respectively, and one of the branched optical signal is shifted by 1-bit earlier by the phase shift element and interferes with the other branched optical signal, of which optical phase is delayed by π/4 (rad), or −π/4 (rad) by the delay element, respectively.
[0030] In FIG. 2 , the phase-shift amount of the phase-shift element is adjusted by its temperature. For example, as the temperature of the phase-shift element rises, its phase-shift amount increases.
[0031] The photo detection circuits (Twin-PD) 12 a and 12 b generate current signals corresponding to the optical phase modulated signals output from the delay interferometer 11 a and 11 b , respectively. Trans-impedance amplifiers (TIA) 13 a and 13 b convert the electric signal currents generated by the photo detection circuits 12 a and 12 b , respectively, into electric signals with a corresponding voltage level and limiter amplifier (LIA) 16 a and 16 b amplify the electric signals, respectively.
[0032] In the discrimination circuits (clock and data recovery circuits; CDR) 17 a and 17 b , the electrical signals output from the LIA 16 a and 16 b , respectively, are converted to an I-channel signal and a Q-channel signal, respectively, which work as clock and data recovery circuits.
[0033] Optical phase error detection unit IA includes low-pass filters (LPF) 14 a , 20 a , and 21 A, a mixer 15 a , and AD converter 22 a . An electric signal output from the TIA 13 a is provided to a mixer 15 a through the low-pass filter 14 a . Also, an electric signal output from the CDR 17 b is provided to the mixer 15 a through the low-pass filter 20 a.
[0034] Similarly, optical phase error detection unit IB includes low-pass filters 14 b , 20 b , and 21 b , a mixer 15 b , and AD converter 22 b . An electric signal output from the TIA 13 b is provided to the mixer 15 b through the low-pass filter 14 b . Also, an electric signal output from the CDR 17 a is provided to the mixer 15 b through the low-pass filter 20 b.
[0035] The cut-off frequencies of the low-pass filters 14 a , 14 b , 20 a , and 20 b are for example about 100 MHz.
[0036] In the optical phase error detection unit IA, the mixer 15 a multiplies output signals of the low-pass filter 14 a and the low-pass filter 20 a . Similarly, in the optical phase error detection unit IB, the mixer 15 b multiplies the output signals of low-pass filter 14 b and the low-pass filter 20 b.
[0037] High frequency components of electrical signals output from the mixers 15 a and 15 b are eliminated by the low-pass filters 21 a and 21 b , respectively. An A-branch monitor signal and a B-branch monitor signal output from the low-pass filters 21 a and 21 b , respectively, are converted into a digital data by A/D converters (ADCs) 22 a and 22 b , respectively.
[0038] Thus, in the optical phase error detection unit IA, the mixer 15 a multiplies the electric signal not processed by CDR 17 a in the A-branch and the electric signal processed by CDR 17 b in the B-branch. Similarly, in the optical phase error detection unit IB, the mixer 15 b multiplies the electric signal not processed by CDR 17 b in the B-branch and the electric signal processed by CDR 17 a in the A-branch.
[0039] A microcontroller 23 a calculates a digital signal output from the A/D converter 22 a and generates a phase adjustment signal for the A-branch. Similarly, a microcontroller 23 b calculates from a digital signal output from the A/D converter 22 b and generates a phase adjustment signal for the B-branch. Details of the calculations are explained later. The microcontrollers 23 a and 23 b are not necessarily separated ones, and may be a common controller.
[0040] The phase adjustment signals generated by the microcontrollers 23 a and 23 b are converted into analog signals and provided to heaters 24 a and 24 b , respectively.
[0041] In the A-branch, temperature of a phase-shift element in the delay interferometer 11 a is adjusted by the heater 24 a controlled by the microcontroller 23 a . In the B-branch, temperature of a phase-shift element in the delay interferometer 11 b is adjusted by the heater 24 b controlled by the microcontroller 23 b . The temperatures of the phase shift elements in the interferometer 11 a and the interferometer 11 b are adjusted separately.
[0042] As phase-shift amounts of the phase-shift elements of the delay interferometers 11 a and 11 b depend on temperature, the phase-shift amounts of the phase-shift elements of the delay interferometers 11 a and 11 b are adjusted by the phase adjustment signals generated by the microcontrollers 23 a and 23 b , respectively.
[0043] A temperature detector 25 detects a temperature around the delay interferometers 11 a and 11 b . A temperature control circuit 26 generates a temperature control signal based on a detection result of the temperature detector 25 . A Peltier device 27 changes the temperature around the delay interferometers 11 a and 11 b , based on the temperature control signal. As the temperature control circuit 26 generates the temperature control signal for maintaining the temperature around the delay interferometers 11 a and 11 b to a predetermined value, the Peltier device 27 maintains the temperature around the delay interferometers 11 a , 11 b at a predetermined temperature according to the temperature control signal.
[0044] The Peltier device 27 is used for supplemental temperature control device to control the temperatures of the phase-shift elements in the delay interferometers 11 a and 11 b . Therefore, if temperature control for the phase-shift amounts of the phase-shift elements in the delay interferometer 11 a and 11 b can be done only by the heaters 24 a and 24 b , respectively, temperature control is done without the temperature detector 25 , the temperature control circuit 26 , or the Peltier device 27 .
[0045] In the optical DQPSK receiver shown in FIG. 2 , when the phase error of the phase-shift element of the delay interferometer 11 a is δA, the A-branch monitor signal is proportional to −sin(δA). Also, when the phase error of the phase-shift element of the delay interferometer 11 b is δB, the B-branch monitor signal is proportional to −sin(δB).
[0046] Therefore, the microcontroller 23 a controls the heater 24 a such that the A-branch monitor signal output from the low-pass filter 21 a becomes zero. Similarly, the microcontroller 23 b controls the heater 24 b such that the B-branch monitor signal output from the low-pass filter 21 b becomes zero.
[0047] As described above, optical phase error detection unit IA and IB, including the mixers 15 a and 15 b , and the low-pass filters 21 a and 21 b , and the microprocessors 23 a and 23 b operate as a phase monitoring apparatus and a phase control apparatus.
[0048] In FIG. 2 , the phases of light of the optical phase modulated signals in the A-branch (I-branch) and the B-branch (Q-branch) are orthogonal. In performing signal extraction separately from the A-branch and the B-branch, when the optical phase control of the delay interferometer 11 a ( 11 b ) is maintained in a target state, a discrimination output component of the CDR 17 a (or 17 b ) is not mixed into the output signal of the TIA 13 b (or 13 a ) of the B (or A)-branch, and therefore the output of the optical phase error detection unit (output of the A/D converter 22 b (or 22 a )) will become 0 [V].
[0049] On the other hand, when the optical phase control of the delay interferometer 11 a ( 11 b ) is deviated from the target state, a discrimination output component of the CDR 17 a (or 17 b ) of the A (or B)-branch is mixed into the output signal of the TIA 13 b (or 13 a ) of the B (or A)-branch, therefore, a +/− voltage will be generated at the output of the optical phase error detection unit IA (or IB) (output of the A/D converter 22 b ). This makes it possible to determine the phase-shift amount and its direction.
[0050] When there is no correlation between the A-branch and B-branch, the time integration value of the multiplication output of both the signals will converge to zero; however, when the output signal of the discrimination circuit 17 a (or 17 b ) of the B (or A)-branch is mixed into the output signal of the trans-impedance amplifier 13 b (or 13 a ) of the B (or A)-branch, the relation represented by the following equation holds.
[0051] That is, letting the output wp of the TIA 13 b (or 13 a ), i.e. the signal not processed by CDR 17 b ( 17 a ) of the B (or A)-branch be [B(A)-arm TIA OUT], and the signal output from the discrimination circuit 17 b ( 17 a ), i.e. the signal processed by the CDR 17 b ( 17 a ) be [A(B)-arm MUX OUT], the relation is represented as follows:
[0000] [ B ( A )-arm TIA OUT]=( n*B ( A )-arm TIA OUT)+( m*A ( B )-arm MUX OUT)
[0052] Here, [B(A)-arm TIA OUT] is the signal to be primarily extracted, and [A(B)-arm MUX OUT] is the signal component which has been mixed. Further, n and m are coefficients generated by optical phase shifting.
[0053] Then, the output of the mixer 15 a , 15 b , [B(A)-arm TIA OUT×A(B)-arm MUX OUT] will be represented as follows.
[0000] [ B ( A )-arm TIA OUT×A-arm MUX OUT]=( n*B ( A )-arm TIA OUT+ m*A ( B )-arm TIA OUT)× A ( B )-arm MUX OUT
[0000] =( n*B ( A )-arm TIA OUT)×( A ( B )-arm MUX OUT)+( m*A ( B )-arm TIA OUT)×( A ( B )-arm MUX OUT)
[0054] Where, (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT), which is the output of synchronized detection, is a term which is supposed to be zero by nature; and when control is deviated from a target state, the term (m*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) will not become zero (i.e. m will not be 0), but will generate a +/− voltage depending on the direction of the optical phase shift.
SUMMARY
[0055] An optical apparatus comprising: a branching unit branching an input light modulated by DQSPK format and thereby outputting a first branched light and a second branched light; a first branch and a second branch inputting the first branched light and the second branched light, respectively, the first branch and the second branch having an interferometer, a photo detector, and discriminator and demodulating I-signal and Q-signal, respectively; and an abnormality detection unit detecting an abnormality of the input light based on a synchronized detection of a first demodulated signal output from the photo detector in the first branch and a first recovered signal output from the discriminator in the first branch, and a synchronized detection of a second demodulated signal output from the photo detector in the second branch and a second recovered signal output from the discriminator in the second branch.
[0056] The above summary describes only an example embodiment. All embodiments are not limited to including all the features in this example.
[0057] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0058] FIG. 1 shows a configuration of a network of optical DQPSK using RZ format in a related art;
[0059] FIG. 2 shows a configuration of an optical DQPSK receiver in a related art;
[0060] FIG. 3A and FIG. 3B are block diagrams showing a configuration of an embodiment;
[0061] FIG. 4 is a diagram showing a DC offset elimination processing of a phase detection unit;
[0062] FIG. 5A and FIG. 5B are block diagrams showing a configuration of an embodiment;
[0063] FIG. 6 is a flow chart of detecting and notifying an abnormality corresponding to Case 1 ;
[0064] FIGS. 7A and 7B are flow chart of detecting and notifying abnormalities corresponding to the Cases 2 and 3 ;
[0065] FIG. 8 is a diagram showing a threshold for the Case 1 ; and
[0066] FIG. 9 is a diagram showing a threshold for the Cases 2 and 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0067] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0068] In the configuration shown in FIG. 2 , when the term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT), which generates a +/− voltage depending on the direction of optical phase shift, can not be detected, the feedback loop may not be able to function properly causing a runaway in the configuration of the invention of the prior application.
[0069] That is, in a normal sate in which the outputs of the TIA 13 a , 13 b and the outputs of the CDR 17 a , 17 b are at generally expected levels, the feedback control functions properly. On the other hand, when optical input state is abnormal, or when any one of the TIA 13 a , 13 b or the CDR 17 a , 17 b is in failure, the above described term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT), which generates a +/− voltage depending on the direction of optical phase shift, can not be detected so that the optical phase error detection value will become abnormal.
[0070] However, in the configuration shown in FIG. 2 , when the term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) cannot be detected, it cannot detect that the optical phase error detection value becomes abnormal.
[0071] Shown below are examples of the state in which the optical phase error detection value becomes abnormal.
[0072] Case 1 : cases when the received optical input includes no optical phase modulated signal, such as an amplified spontaneous emission (ASE) light alone, or cases when the ratio of the signal light S and ASE light (A/ASE) is abnormally small to such an extant as not to be able to detect the above described term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) by a predetermined amount, the detection of optical input disconnection becomes impossible; that is, in which optical input disconnection detection, thereby the detection of abnormalities, is disabled because of a large amount of ASE.
[0073] Case 2 : cases when the distortion of the optical input signal is so large that the optical signal cannot be discriminated, and therefore MUX OUT of the above described term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) is indeterminate.
[0074] As a bandwidth of the linear amplified signal (TIA OUT) is limited by the low-pass filter 14 a , 14 b in the optical phase error detection circuit unit IA or IB, the linear amplified signal has a large tolerance against a residual dispersion, relating to the distortion of the optical input signal.
[0075] Chromatic dispersion generated in the optical transmission line 3 is compensated by the dispersion compensator 6 . As the control of the dispersion compensator 6 is performed in such a way to decrease the error correction rate in a signal communication state, when the delay interferometer optical phase control is abnormal and the optical signal cannot be discriminated, it is impossible to make a dispersion compensation and impossible to ensure a signal communication state.
[0076] Case 3 : cases where the data discrimination circuit (CDR) 17 a or 17 b is abnormal. An abnormality of the data discrimination circuit 17 a , 17 b will cause errors due to the discrimination errors of phase shift of the data and the clock. In such a case, (MUX OUT), which is the discrimination circuit output of the above described term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT), becomes indeterminate and thus optical phase error detection values cannot be obtained, as occurred in Case 2 .
[0077] Case 4 : cases when any one of the TIA 13 a , 13 b and CDR 17 a , 17 b is abnormal, the above described term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) cannot be detected regardless of the optical phase control value.
[0078] Case 5 : cases when optical input is disconnected and the output signals of TIA 13 a , TIA 13 b , CDR 17 a , and CDR 17 b become indeterminate. That makes it impossible to obtain the optical phase error detection value. And it is also the case in which optical input disconnection detection, thereby the detection of abnormalities is disabled due to circuit abnormalities and the like.
[0079] FIG. 3A and FIG. 3B are block diagrams showing a configuration of an embodiment. FIG. 3A shows an optical receiver of the embodiment and FIG. 3B shows a detailed configuration of the optical phase error detection units IA and IB, surrounded by a dotted line in FIG. 3A , and an abnormal state detection unit 300 .
[0080] In FIG. 3A , an input DQPSK signal (or RZ-DQPSK signal) is branched and directed to a delay interferometer 11 a in the A-branch and a delay interferometer 11 b in the B-branch.
[0081] In the delay interferometers 11 A and 11 B, input signals are further branched to two. The delay interferometers 11 a and 11 b include an optical delay element and a phase-shift element, respectively, and one of the branched optical signal is shifted by 1-bit earlier by the phase shift element and interferes with the other branched optical signal, of which optical phase is delayed by π/4 (rad), or −π/4 (rad) by the delay element, respectively.
[0082] In FIG. 3A , the phase-shift amount of the phase-shift element is adjusted by its temperature. For example, as the temperature of the phase-shift element rises, its phase-shift amount increases.
[0083] The photo detection circuits (Twin-PD) 12 a and 12 b generate current signals corresponding to the optical phase modulated signals output from the delay interferometer 11 a and 11 b , respectively. Trans-impedance amplifiers (TIA) 13 a and 13 b convert the electric signal currents generated by the Twin-PD 12 a and 12 b , respectively, into electric signals with a corresponding voltage level and limiter amplifier (LIA) 16 a and 16 b amplify the electric signals, respectively.
[0084] In the discrimination circuits (clock and data recovery circuits; CDR) 17 a and 17 b , the electrical signals output from the LIA 16 a and 16 b , respectively, are converted to an I-channel signal and a Q-channel signal, respectively, which work as clock and data recovery circuits.
[0085] Optical phase error detection unit IA includes low-pass filters (LPF) 14 a , 20 a , and 21 A, a mixer 15 a , and AD converter (ADC) 22 a . An electric signal output from the TIA 13 a (first demodulated signal) is provided to a mixer 15 a through the LPF 14 a . Also, an electric signal output from the CDR 17 b (second recovered signal) is provided to the mixer 15 a through the LPF 20 a.
[0086] Similarly, optical phase error detection unit IB includes LPF 14 b , 20 b , and 21 b , a mixer 15 b , and ADC 22 b . An electric signal output from the TIA 13 b (second demodulated signal) is provided to the mixer 15 b through the low-pass filter 14 b . Also, an electric signal output from the CDR 17 a (first recovered signal) is provided to the mixer 15 b through the LPF 20 b.
[0087] The cut-off frequencies of the LPF 14 a , 14 b , 20 a , and 20 b are about 100 MHz, for example.
[0088] In the optical phase error detection unit IA, the mixer 15 a multiplies output signals of the LPF 14 a and the LPF 20 a . Similarly, in the optical phase error detection unit IB, the mixer 15 b multiplies the output signals of LPF 14 b and the LPF 20 b.
[0089] High frequency components of electrical signals output from the mixers 15 a and 15 b are eliminated by the LPFs 21 a and 21 b , respectively. An A-branch monitor signal and a B-branch monitor signal output from the LPFs 21 a and 21 b , respectively, are converted into a digital data by A/D converters (ADCs) 22 a and 22 b , respectively.
[0090] Thus, in the optical phase error detection unit IA, the mixer 15 a multiplies the electric signal not processed by CDR 17 a in the A-branch (the first demodulated signal) and the electric signal processed by CDR 17 b in the B-branch (the second recovered signal). Similarly, in the optical phase error detection unit IB, the mixer 15 b multiplies the electric signal not processed by CDR 17 b in the B-branch (the second demodulated signal) and the electric signal processed by CDR 17 a in the A-branch (the first recovered signal).
[0091] A microcontroller 23 a calculates a digital signal output from the A/D converter 22 a and generates a phase adjustment signal for the A-branch. Similarly, a microcontroller 23 b calculates from a digital signal output from the A/D converter 22 b and generates a phase adjustment signal for the B-branch. The microcontrollers 23 a and 23 b are not necessarily separated ones, and may be a common controller.
[0092] The abnormal state detection unit 300 has the same configuration as that of the optical phase error detection units IA, IB.
[0093] That is, the optical phase error detection unit IA is a functional unit for obtaining the multiplication result A from the output signal of the TIA 13 a of the A-branch (the first demodulated signal) and the output signal of the CDR 17 b of the B-branch (the second recovered signal). On the other hand, the phase error detection unit IB is a functional unit for obtaining the multiplication result B of the output signal from the TIA 13 b of the B-branch (the second demodulated signal) and the output signal of the CDR 17 a of the A-branch (the first recovered signal).
[0094] In contrast to that, the abnormal state detection unit 300 is a functional unit for obtaining a multiplication result C from the output signal of the TIA 13 a of the A-branch (the first demodulated signal) and the output signal of the CDR 17 a of the A-branch (the first recovered signal), and a functional unit for obtaining a multiplication result D from the output signal of the TIA 13 b of the B-branch (the second demodulated signal) and the output signal of the CDR 17 b of the B-branch (the first recovered signal).
[0095] In such a configuration, the multiplication results C and D in the abnormal state detection unit 300 are as follows.
[0096] The output C, which is the multiplication result from the output signal of the TIA 13 a of the A-branch (the first demodulated signal) and the output signal of the CDR 17 a of the A-branch (the first recovered signal), is at a positive voltage level during a normal state and 0 volt or a lowered voltage level during an abnormal state.
[0097] Similarly, the output D, which is the multiplication result from the output signal of the TIA 13 b of the B-branch (the second demodulated signal) and the output signal of the CDR 17 b of the B-branch (the second recovered signal), is at a positive voltage level during a normal state and 0 volt or under voltage level during an abnormal state.
[0098] In FIGS. 3A and 3B , a microcontroller 301 inputs the multiplication results A, B, C, and D of each functional unit described above and performs abnormality detection. The microcontroller 301 may be common to the microcontrollers 23 a , 23 b in the B-branch and the A-branch in FIG. 3A .
[0099] A microcontroller 23 a calculates a digital signal output from the A/D converter 22 a and generates a phase adjustment signal for the A-branch. Similarly, a microcontroller 23 b calculates from a digital signal output from the A/D converter 22 b and generates a phase adjustment signal for the B-branch. The microcontrollers 23 a and 23 b are not necessarily separated ones, and may be a common controller.
[0100] The phase adjustment signals generated by the microcontrollers 23 a and 23 b are converted into analog signals and provided to heaters 24 a and 24 b , respectively.
[0101] In the A-branch, temperature of a phase-shift element in the delay interferometer 11 a is adjusted by the heater 24 a controlled by the microcontroller 23 a . In the B-branch, temperature of a phase-shift element in the delay interferometer 11 b is adjusted by the heater 24 b controlled by the microcontroller 23 b . The temperatures of the phase shift elements in the interferometer 11 a and the interferometer 11 b are adjusted separately.
[0102] As phase-shift amounts of the phase-shift elements of the delay interferometers 11 a and 11 b depend on temperature, the phase-shift amounts of the phase-shift elements of the delay interferometers 11 a and 11 b are adjusted by the phase adjustment signals generated by the microcontrollers 23 a and 23 b , respectively.
[0103] A temperature detector 25 detects a temperature around the delay interferometers 11 a and 11 b . A temperature control circuit 26 generates a temperature control signal based on a detection result of the temperature detector 25 . A Peltier device 27 changes the temperature around the delay interferometers 11 a and 11 b , based on the temperature control signal. As the temperature control circuit 26 generates the temperature control signal for maintaining the temperature around the delay interferometers 11 a and 11 b to a predetermined value, the Peltier device 27 maintains the temperature around the delay interferometers 11 a , 11 b at a predetermined temperature according to the temperature control signal.
[0104] The Peltier device 27 is used for supplemental temperature control device to control the temperatures of the phase-shift elements in the delay interferometers 11 a and 11 b . Therefore, if temperature control for the phase-shift amounts of the phase-shift elements in the delay interferometer 11 a and 11 b can be done only by the heaters 24 a and 24 b , respectively, temperature control is done without the temperature detector 25 , the temperature control circuit 26 , or the Peltier device 27 .
[0105] In the optical DQPSK receiver shown in FIG. 3A , when the phase error of the phase-shift element of the delay interferometer 11 a is δA, the A-branch monitor signal is proportional to −sin(δA). Also, when the phase error of the phase-shift element of the delay interferometer 11 b is δB, the B-branch monitor signal is proportional to −sin(δB).
[0106] Therefore, the microcontroller 23 a controls the heater 24 a such that the A-branch monitor signal output from the low-pass filter 21 a becomes zero. Similarly, the microcontroller 23 b controls the heater 24 b such that the B-branch monitor signal output from the low-pass filter 21 b becomes zero.
[0107] As described above, optical phase error detection unit IA and IB, including the mixers 15 a and 15 b , and the low-pass filters 21 a and 21 b , and the microprocessors 23 a and 23 b operate as a phase monitoring apparatus and a phase control apparatus.
[0108] In FIG. 3A , the phases of light of the optical phase modulated signals in the A-branch (I-branch) and the B-branch (Q-branch) are orthogonal. In performing signal extraction separately from the A-branch and the B-branch, when the optical phase control of the delay interferometer 11 a ( 11 b ) is maintained in a target state, a discrimination output component of the output signal of CDR 17 a (the first recovered signal) (or 17 b /the second recovered signal) is not mixed into the output signal of the TIA 13 b (the second demodulated signal) (or 13 a /the first demodulate signal) of the B (or A)-branch, and therefore the output of the optical phase error detection unit (output of the A/D converter 22 b (or 22 a )) will become 0 [V].
[0109] Moreover, logic inversion circuits 210 a , 211 a ( 210 b , 211 b ) are provided between the LPFs 14 a , 20 a ( 14 b , 20 b ) and the mixer 15 a ( 15 b ), which have an integration function in the phase error detection units IA, IB. Similarly, a logic inversion circuit is provided in the functional unit for detecting and notifying an abnormal state 300 as well.
[0110] This is because an optical phase error detection value is feeble, and the DC offset voltage generated in the circuit components used for the phase error detection unit is not negligible. Therefore, DC offset elimination processing is performed through computation by the microcontroller 301 of a total of four kinds of outputs A, B, C, and D which are obtained by subjecting each of the TIA outputs and the CDR outputs to logic conversion/inversion and multiplication.
[0111] FIG. 4 is a detailed drawing to illustrate the above described matter; there is shown as the representative only the A-branch which includes Bessel LPFs 14 a , 20 a , analog switches 210 a , 211 a as the logic inversion circuit, a mixer 15 a , a LPF 20 a , and an A/D converter 22 a of FIG. 3 .
[0112] In FIG. 4 , the output of the TIA 13 a is subjected to the LPF 14 a to provide a differential output A 1 −A 2 , and the output of the CDR 17 b is subjected to the LPF 29 a to provide a differential output B 1 −B 2 .
[0113] Let the DC offset voltages at the input/output units of the mixer 15 a be respectively DC A , DC B , and DC out as shown in FIG. 4 . Further letting the optical phase error detection outputs, which are obtained through the logic conversion/inversion processing (polarity inversion processing), performed by controlling the analog switches 210 a , 211 a by microcontroller 301 , be W 1 to W 4 respectively, the outputs of the mixer 15 a will be given as follows.
[0114] The output will take the following four values:
[0000] W 1= DC out +( A 1− A 2+ DC A )( B 1− B 2+ DC B )
[0000] W 2= DC out +( A 2− A 1+ DC A )( B 1− B 2+ DC B )
[0000] W 3= DC out +( A 2− A 1+ DC A )( B 2− B 1+ DC B )
[0000] W 4= DC out +( A 1− A 2+ DC A )( B 2− B 1+ DC B )
[0000] By using these four values, the following computation is performed by the microcontroller 301 .
[0115] Thus, the result is given as W 1 +W 2 +W 3 +W 4 =4(A 1 −A 2 )(B 1 −B 2 ) showing that providing inversion switches 210 a , 211 a as shown in FIGS. 3 and 4 makes it possible to eliminate DC offset generated in the circuit.
[0116] FIG. 5A and FIG. 5B are block diagrams showing a configuration of another embodiment. In contrast to the configuration of FIG. 3A and FIG. 3B , in this embodiment, a node-switching circuit 302 is provided and abnormal state detection unit 300 is not provided. Thus, by controlling the node-switching circuit 302 through the microcontroller 301 so as to function the optical phase error detection unit for optical phase error detection or abnormal state detection by time division, it simplifies the circuit configuration.
[0117] FIGS. 6 and 7 show the operational processing flow of a functional unit for detecting and notifying an abnormal state 300 corresponding to the Cases 1 to 5 described above, which cause problems in the related art configurations, described in FIG. 2 for example.
[0118] Hereinafter, referring to such operational flow, the operation of embodiments according to the present invention in the Cases 1 to 5 will be described.
[0119] First, temperature of the phase-shift elements in the delay interferometers 11 a and 11 b are stabilized by utilizing the heaters 24 a , 24 b (step S 0 ). Next, it is judged whether or not there is a signal communication (step S 1 ) in the processing circuit of data A and data B, which is positioned aft-stage of the CDR 17 a , 17 b and which is not shown in FIG. 5A .
[0120] The absence of signal communication indicates a state in which there is no incoming signal, and the presence of signal communication is a state in which a signal with an error rate Pe of at least not less than about 10 −2 is obtained regardless of the signal quality.
[0121] (Case 1 )
[0122] When it is judged that there is signal communication (Yes at step S 1 ), if the abnormality detection operation output value determined by the microcontroller 301 from the signal determined by the abnormal state detection unit in FIG. 3A , 3 B, 5 A, or 5 B is larger than a first threshold TH 1 (No at step S 2 ), it is judged that there is no abnormality detection (step S 3 ).
[0123] FIG. 8 illustrates the threshold for the Case 1 . That is, Case 1 is a case in which the received optical input is the ASE light alone and does not include an optical phase modulated signal, or a case in which S/ASE ratio is extremely small to an extent that the term (n*B(A)-arm TIA OUT)×(A(B)-arm MUX OUT) described above (hereinafter, simply referred to as * term) cannot be detected.
[0124] In FIG. 8 , with an abscissa being S/ASE [dB], there are shown on the ordinate the multiplication results C and D; that is, the values represented by the following expressions respectively:
[0000] (A-arm TIA OUT×A-arm)/Rx_POW_MON_A
[0000] (B-arm TIA OUT×B-arm MUX OUT)/Rx_POW_MON_B
[0125] The numerator of the above equation is a synchronized detection output of the output signal of the TIA 13 a (the first demodulation signal) ( 13 b /the second demodulation signal) of A (B) arm and the output signal (MUX OUT) of the CDR 17 a (the first recovered signal), ( 17 b /the second recovered signal); the denominator of the above equation is an optical input power monitor value; and the entire term of numerator/denominator indicates the value processed by the microcontroller 301 .
[0126] Then, considering that the optical input power [mW] is proportional to the TIA output, the synchronized detection output of the same branch (Arm) is divided by the optical input power monitor value so that normalized output is indicated on the ordinate.
[0127] Further, since the numerator acts on the input signal optical power S [mW], and the denominator acts on the total optical power (S+ASE) [mW], an S/ASE abnormality judgment threshold VTH 1 is set from allowable S/ASE using the characteristics that the output will vary in the ratio of S[mW]/(S+ASE)[mW].
[0128] However, this requires a premise that the judgment threshold VTH 1 is a threshold by which S/ASE ratio abnormality can be judged when there is no other abnormality.
[0129] Referring back to FIG. 6 , if the input signal optical power S is larger than the S/ASE abnormality judgment threshold VTH 1 (No at step S 2 ), no abnormality is detected (step S 3 ).
[0130] On the other hand, if the input signal optical power S is not larger than the S/ASE abnormality judgment threshold value VTH 1 during abnormality detection operation (Yes at step S 2 ), it is judged to be abnormal and the control of the delay interferometer 11 a ( 11 b ) by the microcontroller 23 a ( 23 b ) is temporally halted, that is, the status quo is maintained, thereby causing the optical amplifier AMP on the optical transmission line 3 to perform control to decrease the input light and update the Psig/Pase ratio (step S 3 ).
[0131] Thus, control is performed such that a control signal is inserted into a predetermined channel from the receiver and sent towards the transmitter, and the ratio of the signal light level to the ASE light level (Psig/Pase) is updated at each optical amplifier AMP.
[0132] Based on such control, control of the delay interferometer is restarted after the control and updating at the optical amplifier AMP (step S 4 ).
[0133] After restarting the control of delay interferometer, abnormality detection operation is further performed as with the step S 2 described above, to make judgment with reference to the threshold VTH 1 (step S 5 ).
[0134] Then, when the number of updates of the optical amplifier control as described above becomes larger than N 3 for example (Yes at step S 6 ), it is judged that discrimination improvement by the discrimination circuit (CDR) 17 a , 17 b becomes impossible or there is a hardware fault, and an alarm ALM is output from the microcontroller 301 (step S 7 ).
[0135] (Case 2 )
[0136] Case 2 is a case in which because of large waveform distortion, the optical input becomes a signal with an error rate Pe of not larger than 10 −2 .
[0137] Therefore, in such a case, it is judged that there is no signal communication at the signal communication state judgment in FIG. 6 , (No at step S 1 ). Then, processing advances by moving to the flow of FIGS. 7A and 7B .
[0138] That is, the case in which the output MUX OUT of the discrimination circuit 17 a ( 17 b ) in the above described * term becomes indeterminate.
[0139] In FIG. 9 , with the abscissa being the chromatic dispersion, there are shown on the ordinate the multiplication results C and D as with FIG. 8 ; that is, the values represented by the following equation:
[0000] (A-arm TIA OUT×A-arm MUX OUT)/Rx_POW_MON_A
[0000] (B-arm TIA OUT×B-arm MUX OUT)/Rx_POW_MON_B
[0140] When the data discrimination in the discrimination circuit (CDR) 17 a ( 17 b ) has been extremely degraded (when the error rate becomes extremely large), due to the waveform distortion including residual dispersion, the above described term (MUX OUT) becomes indeterminate and the numerator converges to zero.
[0141] The effect of error rate of the MUX OUT term, which is the output of the discrimination circuit 17 a ( 17 b ), on the ordinate of FIG. 9 will be the error rate itself. Thus, when the error rate is given as Pe=10 −2 , the likelihood of the MUX OUT term will be reduced at the rate of 10 −2 thereby affecting the ordinate.
[0142] Further, the trans-impedance amplifier output (TIA OUT) has a high residual dispersion resistance since the bandwidth of the linear amplified signal of input signal is limited by the LPF (Bessel Fil) 14 a ( 14 b )
[0143] In FIG. 9 , considering the loop gain of the feedback control of the delay interferometer optical phase, the lower limit value due to waveform distortion for normal functioning is set to be a threshold VTH 2 .
[0144] However, this threshold VTH 2 requires a premise that it is a threshold by which waveform distortion abnormality can be judged when there is no other abnormality.
[0145] Referring to FIGS. 7A and 7B , during the abnormality detection computation by the microcontroller 301 , if the above described multiplication result C or D is larger than judgment threshold VTH 2 with respect to the residual dispersion of the input signal optical power (No at step S 10 ), the process returns to the judgment of Case 1 of FIG. 6 described above.
[0146] On the contrary, when the multiplication result C or D is smaller than the judgment threshold VTH 2 (Yes at step S 10 ), the control of the delay interferometer 11 a ( 11 b ) by the microcontroller 23 a ( 23 b ) is temporally halted, that is, the status quo is preserved, and the dispersion compensator 6 on the network 3 is updated (step S 11 ).
[0147] After the dispersion compensation value is updated by the dispersion compensator 6 , control on the delay interferometer 11 a ( 11 b ) is restarted (step S 12 ).
[0148] After restarting control of the delay interferometer, further abnormality detection computation is performed as with the above described step S 2 , and judgment is made with reference to the threshold VTH 2 (step S 13 ).
[0149] When the computation result output C or D described above is larger than the threshold VTH 2 , the process returns to the judgment of Case 1 previously described in FIG. 6 (No at step S 13 ).
[0150] Then, when the number of judgments that the computation result output C or D is smaller than the threshold VTH 2 becomes larger than N 1 (Yes at step S 14 ), it is judged that improvement of the discrimination circuit (CDR) 17 a ( 17 b ) only by the dispersion compensator 6 is not possible (NG) (step S 15 ).
[0151] (Case 3 )
[0152] In Case 3 , in a similar fashion with Case 2 , when the output of the discrimination circuit (CDR) 17 a , 17 b becomes indeterminate due to the threshold abnormality thereof in a similar fashion with Case 2 , the processing is as follows.
[0153] That is, in FIGS. 7A and 7B , the dispersion compensation control by the dispersion compensator 6 and the phase control on the delay interferometer 11 a ( 11 b ) are temporally halted, and thereafter the threshold of the discriminator (CDR) 17 a ( 17 b ) and the phase control are updated (step S 16 ).
[0154] Then, after the update of control value, control on the dispersion compensator 6 and phase control on the delay interferometer 11 a ( 11 b ) are restarted (step S 17 ).
[0155] Then, when the number of judgments that computation result output C or D is smaller than the threshold VTH 2 becomes larger than N 2 (Yes at step S 19 ), the discrimination point of the discrimination circuit (CDR) 17 a ( 17 b ) is returned to the original state (step S 20 ), and it is judged that improvement of the dispersion compensation by the dispersion compensator 6 and the discrimination output by the update of the threshold of the discrimination circuit (CDR) 17 a ( 17 b ) is not possible (step S 21 ).
[0156] In such a case, since ASE light is large, or the hardware is abnormal, a countermeasure is taken by improving the signal to ASE ratio of the optical amplifier AMP on the network 3 (step S 22 ).
[0157] (Case 4 and Case 5 )
[0158] Case 4 is a case in which either of the output signal of the trans-impedance amplifier (TIA) (the first/second demodulated signal) or the output signal of the discrimination circuit (CDR) 17 a ( 17 b ) (the first/second recovered signal) is abnormal, and in which the control value updating processing in the above described Cases 1 to 3 will not allow recovery. That is, it is judged that the optical input power monitor value is normal and any of input light loss detection unit or fore-stage units before the interferometers is likely to be in fault.
[0159] Further, in Case 5 , when output of the abnormal state detection unit is abnormal and shows no change during a series of abnormality detection control flow of the above described Cases 1 to 3 , it is judged that input light loss detection unit is likely to be in failure regardless of the failure judgment of other units in Case 4 .
[0160] As described above, utilizing a circuit for detecting and notifying an abnormal state, a runaway of the feedback control of the delay interferometer optical phase is prevented. Also, utilizing an abnormality detection computation and control unit, the dispersion compensator, the optical amplifier, and others are halted during abnormality and recovered therefrom upon detection of abnormality.
[0161] In the control procedure for the above described abnormality recovery, as the abnormalities can happen at the same time, it is preferable to recover the abnormalities and avoid the abnormalities affecting the dispersion compensation amount feedback control of the dispersion compensator in the optical receiver unit or the delay interferometer optical phase feedback control embedded in the optical receiver in order to avoid runaway.
[0162] Thereafter, abnormality recovery control is performed in which abnormality recovery is performed by time division so that abnormality judgment is recovered on the abnormality occurrence causes.
[0163] Then, from a series of the results of abnormality detection control which is performed by such time division, abnormality occurrence locations are identified.
[0164] Although a few preferred embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claim and their equivalents. | An optical apparatus comprising: a branching unit branching an input light modulated by DQSPK format and thereby outputting a first branched light and a second branched light; a first branch and a second branch inputting the first branched light and the second branched light, respectively, the first branch and the second branch having an interferometer, a photo detector, and discriminator and demodulating I-signal and Q-signal, respectively; and an abnormality detection unit detecting an abnormality of the input light based on a synchronized detection of a first demodulated signal output from the photo detector in the first branch and a first recovered signal output from the discriminator in the first branch, and a synchronized detection of a second demodulated signal output from the photo detector in the second branch and a second recovered signal output from the discriminator in the second branch. | 7 |
RELATED INFORMATION
[0001] This application claims priority to Chinese Patent Application No. 01103777.6 filed Feb. 12, 2001, entitled “COMPOSITION AND METHOD FOR EFFECTING WEIGHT REDUCTION” and the disclosure is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to dietary supplements and foods for reducing weight gain, effecting weight loss and causing favorable changes in body composition. More specifically, the invention relates to the field of herbal compositions, especially decoctions for oral administration containing rhubarb and other herbal ingredients.
BACKGROUND OF THE INVENTION
[0003] Body weight and body composition is determined by the competing balance of food intake and energy expenditure. Although both genetic and environmental factors can contribute to obesity, the most common cause of weight gain and an overweight body composition is excessively high caloric intake accompanied by a lack of physical activity. The resulting accumulation of surplus fat places overweight or obese individuals at increased risk of illness from hypertension, lipid disorders, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea and respiratory problems, certain cancers, and a wide variety of other diseases and undesired physiological conditions, as well as overall mortality. According to a study, the proportion of overweight individuals in the United States increased from 25% in 1980 to 33% in 1991. (Third National Health and Nutrition Examination Survey, 1991). In 1998 the National Institutes of Health reported that over 55 percent of the U.S. population are now considered overweight or obese. ( Obesity Clinical Guidelines: NIH Statement Jun. 3, 1998, press release).
[0004] Obesity may become partially reversed or prevented by employing diet or nutrition and behavior modification programs or by using pharmaceutical intervention. Among the most widely administered drugs are: orlistat, which reduces the amount of dietary fat that is absorbed from the intestine; sibutramine, which suppresses appetite by inhibiting the re-uptake of norepinephrine and serotonin; fenfluramine and d-fenfluramine, which suppress appetite by both releasing serotonin and then inhibiting its re-uptake; and phentermine, which suppresses the appetite by stimulating the release of norepinephrine.
[0005] Most weight reduction drugs typically achieve only a 5-10% decrease in body weight. ( National Task Force on the Prevention and Treatment of Obesity: Long - term pharmacotherapy in the Management of Obesity, JAMA 276:1907-15, 1996). In addition, most drugs have mild to serious side effects. For example, the once popular appetite suppressant drug “Fen-Phen” (the combination of fenfluramine and phentermine), which gave a 15-20% reduction in body weight, was clinically determined to have significantly increased the risk of heart valve damage. (F. Brenot et al., Appetite Suppressant Drugs and the Risk of Primary Pulmonary Hypertension, N. Engl. J. Med., 335:609-16, 1996). Consequently, after a number of confirmed “Fen-Phen”—related patient deaths, most of the drugs containing fenfluramine have been recalled and withdrawn. (Connolly H. M. et. al., N. Eng. J. Med. 337:581-88, 1997). In 1999 the FDA removed fenfluramine from the market. Other common side effects include dizziness, headaches, rapid pulse, palpitations, sleeplessness, hypertension, diarrhea, and intestinal cramping.
[0006] In addition to adverse side effects, current weight loss drugs may be habit forming, as exemplified by drugs containing amphetamines, and the initial weight reducing effect of many drugs wears off over time, requiring increased dosages to maintain weight reduction. The most serious problem, however, is that the lost weight is frequently regained after the drug is discontinued and the fairly limited utility of these drugs is more than offset by the side effects and other drawbacks inherent in their use.
[0007] The following table provides a synopsis of some of the characteristics of the most popular weight loss drugs and notes some of the impediments to wide-scale use:
Generic Name and Mechanism Brand Name Comments Amphetamine + Adderall Not commonly used Dextroamphetamine therapeutically for obesity. sympathomimetic amine High abuse potential. appetite suppressants Benzphetamine sympatho- Didrex; Not commonly used mimetic amine appetite Benzfetamine therapeutically. High abuse suppressant potential. Bromocriptine stimulates Ergoset; Not approved in US for dopamine type-2 receptors Parlodel obesity. Used “off label”. and antagonizes type-1 receptors in brain Dexfenfluramine Redux Approved 04/96 in US with appetite suppressant via no limit on duration of use. serotonin release and Voluntarily withdrawn in serotonin reuptake block; US 09/15/97 due to heart the d isomer of fenflu- valve damage. ramine; thought to be less addicting than most others Dextroamphetamine Dexedrine Not approved in US for sympathomimetic amine obesity. Used “off label”. appetite suppressant Highly abused. Diethylpropion sympatho- Amfepramone; Possible link to primary mimetic amine appetite Tenuate; pulmonary hypertension suppressant Tenuate Dospan Fenfluramine racemic Pondimin; One component of “fen/ mixture dexfenfluramine Ponderal phen”; Approved in US in and L-fenfluramine; 1973. Voluntarily with- mechanism like dexfenflu- drawn in US due to heart ramine (see above), except valve damage 09/15/97 also affects dopamine availability Fluoxetine selective Prozac Not approved in US for serotonin reuptake inhibitor obesity. FDA application (SSRI) was withdrawn by manu- facturer. Used “off label”. Mazindol sympathomimetic Mazanor; Approved in US in 1973. amine appetite suppressant Sanorex Rarely used. High abuse potential. Methamphetamine Desoxyn; Rarely used for obesity. sympathomimetic amine Methampex High abuse potential. appetite suppressant Orlistat Xenical Recommended for approval not a CNS-active drug; in US 05/15/97; FDA panel decreases the amount of fat reconsidered and split 5-5 absorbed from the diet by on 03/16/98; due to possi- 30%. ble link to breast cancer Phendimetrazine sympatho- Adipost; Approved in US in 1961. mimetic amine appetite Anorex; Rarely used. suppressant Bontril; Parzine; Phendiet; Plegine; Wehless Phentermine sympatho- Adipex-P; Approved as “resin mimetic amine appetite Fastin; complex” in 1959. suppressant Ionamin; Approved as hydrochloride Oby-Cap; in 1973. The other Phentamine; component of “fen/phen”. T-Diet; Zantryl Phenylpropanolamine Acutrim; Available “over the sympathomimetic amine Dexatrim; counter”. appetite suppressant Phenoxine; Phenyldrine; Propagest; Rhindecon Sibutramine Meridia Approved in US, 11/97 inhibits reuptake of dopamine, norepinephrine, and serotonin in brain
[0008] Various natural herbal weight reduction formulas have been suggested as safer alternatives to both prescription and over-the-counter weight loss compounds. Generally, herbal weight loss formulas have fewer side effects when properly formulated and administered. Despite the fact that herbs are natural substances, however, some herbal formulas can still be abused. For example, improper administration of herbal weight loss formulas based primarily on ma huang (ephedra) and high caffeine-containing herbs, such as guanrana and kola nut, may result in diminished energy and a depleted body.
[0009] New compounds for treatment of humans are often tested in animal models to insure their safety and efficacy. A number of rat models have been used to study the effect of drugs on obesity. Diet-related obesity can be created in the Osbom-Mendel, Wistar and Sprague-Dawley rats by altering their diets to increase caloric consumption. This is usually accomplished by increasing the percentage of fat in a carefully controlled diet and measuring a series of physiologic parameters that indicate changes in energy metabolism, weight gain, weight loss, body composition, and other indicia of overall health and the balance between food intake and energy expenditure. These rats experience the increased weight and fat deposition characteristically seen in obese humans. Using these models, compounds that are candidates for agents to control body weight and composition are tested for safety and efficacy. Typically, drugs that prevent weight gain or cause weight loss in rat models are also effective in humans, albeit at a slightly lower level of efficacy. Given the serious problems associated with obesity, and the significant drawbacks associates with many weight loss compounds, a need exists for a safe and effective composition that reduces weight gain, causes weight loss, and improves body composition.
SUMMARY OF THE INVENTION
[0010] The present invention is comprised of compositions and methods for effecting weight reduction, specifically, herbal formulations and methods for their administration to reduce body weight prevent weight gain and lower blood lipid and sugar levels. At the physiological level, the compositions alter the balance of food intake and energy metabolism to favor weight reduction and the improvement of body composition by reduction of fat and overall lipid levels. The compositions are comprised of a combination of more than one herb, and specifically chemical extracts from herbs, that are formulated in a special combination such that the individual components are combined for their individual utilities in the weight loss context, as well as for their synergistic effect in the complete composition of the invention. Each herb is identified by its botanical characteristics, as well as by the chemical compounds contained within the plant that may be extracted by chemical manufacturing processes. Accordingly, chemical compounds and individual constituents of the herbs, individually and collectively, that mimic the effect of the herbs and herbal extracts may be substituted for the actual herbs obtained from nature without departing from the spirit and utility of the invention. In a preferred embodiment, the compositions of the invention include another rhubarb that is specially processed in a decoction and used in combination with other herbal compositions and extracts that enhance the physiological utility of rhubarb and its derivatives. In a preferred embodiment, the composition contains the functional chemical components of rhubarb in combination with other agents that allow the ingestion of rhubarb extracts without side effects.
[0011] In use, the compositions of the invention can be administered orally in a liquid or tablet form and may be combined with food as part of an obesity treatment regimen or as a dietary or fitness supplement. When provided to non-humans, the compositions of the invention may be administered separately or may be combined with ordinary feed or liquid nourishment to effect the alterations in body composition as described herein. Thus, the compositions of the invention include the herbal compositions described herein in oral dosage form, or in combination with any of the usual pharmaceutical or nutritional media employed in the art for oral liquid preparations, e.g., suspensions, elixirs, and solutions. Generally, media containing water, oils, alcohols, flavoring agents, preservatives, coloring agents and the like may also be used for flavor, texture, or shelf-life enhancement. Carriers such as starches, sugars, diluents, granulating agents, lubricants, binders, disintegrating agents, and the like may be used to prepare oral solids (e.g., powders, capsules, pills, and tablets). Controlled release forms may also be used. Because of their ease in administration, tablets, pills, and capsules represent advantageous oral dosage unit forms, in which case solid pharmaceutical carriers are employed. If desired, tablets may be sugar coated or enteric coated by standard techniques. While the herbs and herb extracts of the invention are naturally derived from plants that are edible, the compositions of the invention can be administered as herbs or direct extracts of herbs, but one or more herbs can also be substituted with the chemical compounds or functional equivalents that are derived from such herbs. For example, one component of an embodiment of the invention is turmeric. The main functional ingredient of turmeric is known to be curcumin, an organic molecule whose structure and function are well known. Thus, consistent with the invention, the turmeric herb may be replaced in some applications with the organic molecule contained therein. Moreover, the compositions of the invention can be combined with ordinary foods to enhance the value of the weight control capabilities. For example, the compositions can be mixed with soft drinks, food supplements, candy, or high-energy bars, and virtually any other food that can be supplemented with a powder or liquid. Thus, the invention specifically includes food substances of specific types combined with the composition of the invention in specified forms and quantities.
[0012] A preferred embodiment of the herbal formulation is comprised of a combination of rhubarb root and stem ( radix et rhizoma rhei ), astragalus root ( radix astragali ), red sage root ( radix salviae miltiorrhizae ), turmeric ( rhizoma curcumae longae ), and dried ginger ( rhizoma zingiberis officinalis ). The herbal formulations are preferably administered orally in a dosage range that results in a decrease of body weight, normalization of the metabolic rate, and reduction of blood lipid and sugar level. In a preferred experimental application of the invention, rats administered with 5 grams per day of the herbal composition lost about 39% of their pretreated weight and 60% of their pretreated cholesterol level.
DESCRIPTION OF THE FIGURES
[0013] [0013]FIG. 1 shows the cumulative weekly weight gain (grams) measured over eight weeks in five groups of rats administered Fenfluremine (FF), a low dosage of one embodiment if the decoction of the invention (DRD-L), a higher dose of the decoction (DRD-H), a pair fed (PF) water-only group with a measured food intake, and a control.
[0014] [0014]FIG. 2 shows weight gain (grams) at the 56 day interval for the five groups of FIG. 1.
[0015] [0015]FIG. 3 shows food efficiency measured as grams of weight grain per gram of food consumed for the five groups of FIG. 1.
[0016] [0016]FIG. 4 shows food efficiency measured as weight gain per calorie of food ingested for the five groups of FIG. 1.
[0017] [0017]FIG. 5 shows a dose response curve measuring the percent difference in body weight as a function of five different dosages of the decoction.
[0018] [0018]FIG. 6A shows weight gain in rats fed either an obesity-inducing diet alone, or the diet plus the DRD decoction at day 56.
[0019] [0019]FIG. 6B shows the same study at day 90.
[0020] [0020]FIG. 7 shows the differences in absolute weight of the animals in the five groups of FIG. 1 measured over 56 days.
[0021] [0021]FIG. 8 shows the difference in weight gain of each body composition component over day 56 for the five groups of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention is a pharmaceutically acceptable herbal composition, usually administered as a dietary supplement, to effect weight loss, a reduction in weight gain, or an alteration in body composition. For the purposes of this invention, “pharmaceutically acceptable” compositions are formulated and administered to be non-toxic and, when desired, used with carriers or additives that are approved for administration to humans and animal species. In a preferred embodiment, the composition comprises a decoction of rhubarb root and stem, ( radix et rhizoma rhei ), in combination with other compounds or compositions to enhance the tolerance of rhubarb and increase the efficacy and safety of a formulation derived from a rhubarb-containing decoction. These include astragalus root ( radix astragali ), red sage root ( radix salviae miltiorrhizae ), turmeric ( rhizoma curcumae longae ), and dried ginger ( rhizoma zingiberis officinalis ). When the composition of the invention is added to solid food stuffs, the composition is preferably prepared in a powder form that is constituted from the decoction by conventional techniques. Preferably, depending on the composition and mode of administration, the dosage is between 2 grams to approximately 90 grams and is orally administered on a daily basis. Most preferably, however, approximately 22.5 grams is taken orally each day. For ease of reference, the several different formulations of the invention are collectively referred to herein as the “DRD” decoction.
[0023] Rhubarb ( radix et rhizoma rhei ), also known as “da huang” in traditional Chinese medicine, is an anti-inflammatory and diuretic herb whose effectiveness is controlled by the amount used. In the preferred embodiment of the invention, species of the genus Rheum are used, species of the botanical name Rheum tanguticum Maxim ex Balf, and 2 species of Chinese Rhubarb of the botanical name Rheum palmatum L, and Rheum officinale Baill. From the foregoing, Rheum tanguticum Maxim ex Balf is particularly preferred. When taken in small doses, rhubarb functions as a digestive aid, increases salivary and gastric flow, improves appetite, and cleanses the liver by encouraging bile flow. This cleansing action also encourages the healing process of duodenal ulcers and enhances gallbladder function. Rhubarb has also been described as containing anthraquinones, specifically rhein, emodin, aloe emodin, chrysophanol, and physcion. These compounds are known to exhibit antibiotic functions, and the anthraquinone glycosides (rhein-8-monoglucoside, emodin-6-monoglucoside, aloe emodin-8-monoglucoside, chrysophanol-1-monoglucoside, physcionmonoglucoside are known to exhibit diarrheal function. (Chirikdjian J J, et al. Planta Medica, 1983, (48(1): 34). Also, rhein and emodin inhibit tumor growth in mice.
[0024] In large doses, rhubarb can be used for emptying the bowels thoroughly. As a gentle laxative, rhubarb strengthens the gastrointestinal tract, and tones and tightens bodily tissues. Although known for its therapeutic properties in treating dysenteric conditions, rhubarb also has a beneficial effect on blood chemistry, enhances blood circulation, and lowers serum cholesterol.
[0025] Only roots and root stems of the rhubarb plant are used for medicinal purposes because the leaves are potentially toxic. In addition, rhubarb plants from different climatic regions possess different properties. Preferably, the rhubarb roots used in the preferred embodiments of the present invention are those found Longxi in the Garson Province and other areas in North Central China.
[0026] As an essential ingredient of the present invention, the rhubarb root plays key roles in reducing fat intake, enhancing metabolism and decreasing blood lipid or sugar level. The relative weight percentage of the rhubarb in the preferred embodiments of the decoction is between about 36% to about 44%. In one preferred embodiment of the present invention, the composition contains 40% of the rhubarb roots.
[0027] Turmeric ( rhizoma curcumae longae ) promotes blood circulation. In the natural form, curcumin has been described as containing the following compounds: curcumin and turmerone. The most well-characterized component of turmeric is curcumin. Curcumin has the structure shown in (I)
[0028] where R 1 is —OCH 3 ; R 2 is —OH; R 3 is —H; R 4 is —H; R 5 is —OCH 3 ; R 6 is —OH, and R 7 is H. Curcumin has the chemical name (E, E) 1,7-bis(4-Hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione. In natural curcumin, the carbon-carbon double bonds are in the trans configuration.
[0029] Curcumin is known to inhibit the enzymatic transformation between phosphorylase b and phosphorylase a. ( Curcuma longa; S. Reddy S & B. B. Aggarwal, “Curcumin is a Non-Competitive and Selective Inhibitor of Phosphorylase Kinase,” FEBS Lett. 341:19-22 (1994)). The anti-proliferative properties of curcumin inhibit tumor initiation induced by benzo[a]pyrene and 7,12 dimethylbenz[a]anthracene (M. T. Huang et al., Carcinozenesis 13:2183-2186 (1992); M. A. Azuine & S. V. Bhide, Nutr. Cancer 17:77-83: (1992). Curcumin inhibits the tumor promotion caused by phorbol esters (M. T. Huang et al., Cancer Res. 48:5941-5946 (1998); A. H. Conney et al., Adv. Enzyme Regul. 31:385-396 (1991); Y. P. Lu et al., “Effect of Curcuminon 12-O-Tetradecanoylphorbol-13-Acetate and Ultraviolet B Light-Induced Expression of c-Jun and c-Fos in JB6 cells and in Mouse Epidermis,” Carcinogenesis 15:2263-2270 (1994) and has been shown to inhibit pp60src (epidermal growth factor equivalent) tyrosine kinase via inhibition of phosphorylase kinase.
[0030] Curcumin is an inhibitor of Type I cyclic AMP-dependent protein kinase, the enzyme mainly responsible for activating phosphorylase kinase. The inhibition is competitive with respect to both ATP and the substrate (M. Hasmeda & G. M. Polya, “Inhibition of CyclicAMP-Dependent Protein Kinase by Curcumin,” Phytochemistry 42:599-605 (1996)). Phosphorylase kinase, in turn, increases the migration of inflammatory cells, tumor cells, smooth muscle cells, and other cell types, as discussed above, as well as infectious organisms, increasing both the destructive and proliferative sequelae of the inflammatory response.
[0031] Accordingly, an improved method of treatment of wounds, burns, acne, and eczema, as well as skin damage resulting from exposure to sunlight or exposure to cigarette smoke or nicotine, utilizes inhibition of phosphorylase kinase activity in the affected skin in a mammal, particularly a human. A particularly suitable reagent for inhibiting phosphorylase kinase activity is curcumin.
[0032] Turmeric is also often used to treat conditions such as amenorrhea, dysmenorrhea and other pains in the abdominal region caused by stagnation of blood. In addition, turmeric has antibiotic and anti-inflammatory properties that make it an herbal medicine for a wide variety of other conditions ranging from arthritis to ulcers, flatulence, blood in the urine, bruises, colic, respiratory diseases, chest pains, jaundice, hepatitis, diabetes, menstrual irregularities, hemorrhage, and toothache. It is also effective both as a treatment and a preventive for intestinal parasites.
[0033] Even in high doses, turmeric has not been shown to have any toxicity. Curcumin, the compound responsible for turmeric's yellow color, is considered its primary anti-inflammatory component. See Ammon et al., U.S. Pat. No. 5,401,777, Heng United States Patent 5,925,376. Dimethylbenzyl alcohol, another component of turmeric, benefits the cardiovascular system by normalizing cholesterol, first by reducing it in the blood and then by removing its accumulation in the liver. Turmeric is known for removing arterial plaque, effectively treating anemia, and as a potent hemostatic used to reduce bleeding.
[0034] Turmeric's antioxidant properties are often regarded as more potent than either vitamin C or E. Turmeric's antioxidant properties also account for its use as a food preservative and an inhibitor of rancidity of fats and oils. Turmeric also promotes digestion and can increase bile output by up to 100%.
[0035] In addition to the rhubarb roots described above, turmeric is another ingredient of the invention that enhances metabolism and reduces blood lipid and sugar level. The relative weight percentage of the turmeric in the preferred embodiment of the decoction is between about 24% and about 30% of the herbal composition. In one preferred embodiment of the invention, the composition contains 26-27% turmeric.
[0036] Astragalus root ( radix astragali ) enhances the immune system and helps the body resist virus infections, particularly in the lungs, by increasing production of interferon, an immune factor that inhibits viral growth. Astragalus polysaccharides are known to enhance immune function. The compounds stragaloside I, astragaloside II, astragaloside III, and astragaloside IV are anti-oxidants, and especially inhibit lipid oxidation (CA 1987, 107: P195156p). In the natural form, astragalus has been described as containing astragalan, astragaloside I, astragaloside II, astragaloside III, and astragaloside IV, and astragolin. It also helps eliminate toxins and promote the healing of damaged tissues, including protecting the liver against chemical damage. In the preferred embodiment, Astragalus or “milk retch root” from the Bantou region of Inner Mongolia is preferred. This species has the botanical name Astragalus membranaceus Bge. Var. mongholicus.
[0037] In addition, astragalus increases the production and activity of white blood cells (i.e., T-cells) specifically involved in fighting disease. Clinical studies have shown that cancer patients who take astragalus while undergoing chemotherapy, which severely inhibits natural immune responses, recover faster and live significantly longer than those that do not use this herb. Astragalus eases chemotherapy and radiation side effects and inhibits the spread of tumors.
[0038] Astragalus is rich in polysaccharides and contains glycosides, saponins, and essential fatty acids. Moreover, astragalus helps prevent clotting and has systemic vasodiation properties that help prevent coronary heart disease and improve blood circulation. Its heart tonic properties also lower blood pressure, dilate blood vessels, and strengthen the heart. Furthermore, astragalus facilitates digestion and alleviates digestive ailments. It increases the flow of bile and digestive fluids and, thus, increases metabolism and helps control diarrhea.
[0039] The astragalus plant grows to a height of about 1 meter, with rigid stalks that sprout eight to twelve pairs of leaflets. The medicinal root is covered with a tough, fibrous, yellowish brown skin and is typically sold in flexible slices approximately 15-20 centimeters long. The marrow is yellowish white and has a sweet taste that resembles licorice. The herb is grown mostly in northern China, Japan, and Korea, each region producing its own distinctive variety. All types can be used in formulas calling for astragalus; as noted above, preferred medicinally potent varieties come from inner Mongolia and northern China.
[0040] Astragalus also enhances the overall body energy level, thereby helping to compensate for any possible depleted energy which is often caused by weight loss. In the context of the preferred embodiments of the present invention, astragalus works together with rhubarb and turmeric to achieve a delicate balance point that maximizes weight loss while minimizes energy depletion. The relative weight percentage of astragalus may vary from between approximately 11% to approximately 15%. In one preferred embodiment of the present invention, the herbal composition contains 13.3% weight percent of astragalus.
[0041] Another ingredient, red sage root ( radix salviae miltiorrhizae ) enhances blood circulation and reduces serum levels of cholesterol and other lipids. Red sage has been described as containing tanshinone I, tanshinone IIA, tanshinone IB, isotanshinone I, isotanshinone II, miltirone, methyl tanshinonate, cryptotanshinone, isocryptotanshinone, dihydrotanshinone, tanshinol I, and tansinol II. Tanshinol I and tanshinol II are known to inhibit the proliferation of human tumorous cells (Ryu S Y, et al. Planta Medica, 1997, 63(4):339. Tanshinone exhibits myocardial protection and prevention of myocardial ischemia. It also prevents blood stagnancy in the lower abdomen, especially for those associated with menstrual pain. In a preferred embodiment, red sage root with the botanical name Slvia miltiorrhhiza Bge is used.
[0042] In the present invention, red sage root enhances the function of the cardiovascular system and counter-balances a common side effect of many weight loss drugs, increased risk of heart stress that can lead to actual tissue damage. The relative weight percentage of this ingredient may vary in a range of between approximately 11% to approximately 15%. In one preferred embodiment of the present invention, the composition contains 13.3% red saga root.
[0043] Dried ginger ( rhizoma zingiberis officinalis ) is usually produced by sun-drying the fresh rhizomes, and has been described as containing zingerone, zingiberene, zingiberol, gingerol, shogaol, phellandrene, and camphene. Zingerone, zingiberene, and zingiberol are known to alleviate vomiting and diarrhea, while zingiberene is an anti-inflammatory. In a preferred embodiment, a ginger species with the botanical name Zingiber officinale Rosc. is used. When used in an herbal decoction, the dried rhizomes are more potent than the fresh. Ginger aids digestion and assimilation, and is often added to herbal formulas to facilitate rapid delivery of the other herbs' therapeutic benefits. Ginger contains a digestive food enzyme called zingibain, which exceeds papain (derived from papaya) in digestive potency. Ginger also increases the concentration of the carbohydrate-digesting enzyme amylase in saliva. Further down the digestive tract, ginger improves digestion by activating peristalsis. Ginger can be used to relieve vomiting and to soothe the stomach and spleen.
[0044] In addition, research has found that ginger may help prevent strokes and the hardening of arteries. The active ingredient of ginger, gingerol, is believed to inhibit an enzyme that causes blood cells to clot. Ginger also lowers serum cholesterol, improves circulation, reduces platelet aggregation, and is a regulator of blood cholesterol. Ginger is also effective as a diaphoretic to encourage sweating to remove toxic waste and is used to increase kidney filtration.
[0045] As an ingredient of the present invention, dried ginger increases tolerance and reduces the side-effects of the remaining ingredients. Its relative weight percentage may vary in a range of between approximately 6% to approximately 8% of the composition. In one preferred embodiment of the invention, dried ginger constitutes 6-7% of the composition.
[0046] Herbal decoctions are produced by a characteristic method of preparing an aqueous extract of specific quantities of herbs. Traditionally, decoctions are prepared in a clay pot, but they can also be prepared in glass, unchipped enamel, or high-quality stainless steel containers without interfering with the herbs' properties. Decoctions should not be prepared in iron, copper, aluminum, or any other type of metal containers that can alter the chemistry of the herbs. The main advantages of an herb-derived composition prepared by the decoction method are thorough extraction of the herbs' complete medicinal potential, rapid absorption, and swift onset of therapeutic effects when administered.
[0047] Generally, a rhubarb-water mixture is prepared separately and added to a mixture of at least one of the remaining ingredients having been separately soaked to form an herbal mixture. When the herbal mixture contains each of turmeric, astragalus, red sage and ginger, the combination may be referred to as a four-herb mixture, and when combined with the rhubarb-water mixture, as a five-herb mixture. In one preferred embodiment, an herbal composition comprising rhubarb, astragalus, red sage root, turmeric, and dried ginger in accordance with the principles of the present invention is prepared by decoction as follows. A measured amount of the five herbs described above should be weighed according to the following proportions: 40.0% rhubarb roots, 26.7% turmeric roots, 13.3% astragalus roots, 13.3% red sage roots, and 6.7% dried ginger roots. The rhubarb roots are then placed in a first stainless steel container with a quantity of clean water approximately 6 to 8 times the weight of the rhubarb roots. Similarly, the other four herbs are placed together in a second stainless steel container with clean water approximately 6 to 8 times the combined weight of the herbs. When 1500 grams ttoal weight of the herb mixture is used, the later for herbs are placed in 5400 ml water. All of the herbs are allowed to soak for 6 to 12 hours, preferably at least 8 hours. The herbal mixture is formed when the herbs and water in the second container are brought to a rolling boil, with constant stirring, and simmered at the boiling temperature for approximately 20 minutes (or until the fluid is reduced by half) to create a four-herb mixture. The cold rhubarb-water mixture in the first container is then added to the contents of the second container to yield a five-herb mixture. The combined mixture is heated to and maintained at about 85 to 95° C., or simmered at a temperature just below the boiling point of the mixture, for approximately 20 minutes with constant stirring. It is important not to heat the five-herb mixture to a boil because boiling removes very important rhubarb volatiles from the solution. The mixture is then allowed to cool to about 40 to 50° C. Neither ice nor any other cooling mechanism should be used for the cooling process, however, because the herbs must be allowed to react with each other during the slow cooling period. The resulting decoction exhibits the weight reducing effect of the invention although further processing may be performed to produce a composition in a particular form e.g. a concentrated liquid, powder, etc. or other formulation suited for a particular mode of administration.
[0048] To remove the insolubles, the cooled mixture is then filtered and strained by conventional methods, preferably at least twice by using multi-layered medium filter paper, filter press, centrifuge cloth-lined sieve or cheesecloth. The resulting warm final liquid extract may be directly administered orally, preferably between meals on an empty stomach for rapid assimilation.
[0049] In another embodiment, the above final liquid extract is then condensed into a concentrated liquid extract by evaporation. The concentrated liquid extract may be placed in a rotary evaporation flask and heated at the temperature below 85° C. until the extract is condensed to about {fraction (1/10)} of its original volume.
[0050] In another preferred embodiment, a conventional freeze-drying process is used to condense the final liquid extract into a powder form. Preferably, the final liquid extract is cooled at −80° C. and then placed on a standard laboratory freeze drier overnight to transform the extract into powder form. To create a lyophilizate, 10 mL of extract was quickly frozen in a dry ice/ethanol bath. The sample was freeze-dried for 13 hours, and a very fine powder was obtained. There was no evidence of gums or resins in this mixture. The 10 mL of extract yielded 0.5 g of particulate matter. The powder was dissolved in 0.68 mL of water and the resulting solution was slightly thick and dark brown in color, and yielded a product that is suitable for commercial use.
[0051] Both the final liquid extract and the freeze-dried powder contain a quantify of the herbal mixture with a dry weight in the range of 2 grams to 30 grams. The resulting herbal liquid or the powder may be incorporated into a pill, tablet or other pharmaceutically acceptable form and is then taken by patients as one dose with a daily dosage of up to three doses per day. Alternatively, the final liquid extract or powder form is mixed with a food or food supplement such as beverages, energy bars, protein or carbohydrate supplements or powders and other similar edibles. The total dosage administered will, of course, depend on the clinical indication of the patient or user. For the chronically or severely obese, higher dosages may be administered under the direct supervision of a physician who carefully monitors a patient's entire metabolic and biochemical profile. As a guideline, the total amount given to a patient daily should effect a targeted weight loss goal without causing side effects, such as excessive bowel movement or possible diarrhea. Generally, the maximum daily dosage is such that patients shall not have bowel movement three times more than usual after taking this supplement. In a clinical setting, the patient's physical reaction may be monitored after taking the first dose to decide whether the second or third dose should be given. The amount of the second or third dose may also be adjusted accordingly. In a preferred embodiment of this invention, the herbal mixture in powder form with dry weight of approximate 22.5 gram per day is given to patients. Alternatively, when the final liquid extract, the concentrated liquid, or the powder form is mixed in foods, the dosage can be altered to reflect the nature of the foods or the patterns of intended consumption ranging from the maximum permitted in the clinical setting described above to smaller dosages for over-the-counter foods or beverages.
[0052] Having generally described the present invention, a further understanding may be acquired by reference to the following examples, representing experimental studies conducted to investigate the effects of an herbal formula prepared as a decoction comprising rhubarb, astragalus, red sage root, turmeric, and dried ginger on weight reduction and body composition of rats.
EXAMPLES
Example 1
Male Sprague-Dawley Rats—2.5/5.0 Dry Berbal Administration
[0053] Male Sprague-Dawley rats were made obese by dietary intervention only. After 180 days, when their average weight reached about 620 grams, they were administered daily by stomach intubation (5 mL) either the amount of the decoction DRD extracted from 2.5 grams or 5.0 grams of the dry herbal. Over a 90-day treatment period, the rats administered the 2.5 grams DRD lost about 30% of their pre-treatment body weight, and the fat/lean ratio decreased by 13 fold. The rats administered the 5.0 grams DRD lost about 39% of their pre-treatment weight, and their fat/lean ratio decreased by 25 fold. The metabolic rates of the rats treated with either dose of DRD were restored to normal. The obese controls gained 20 grams and the normal rats gained approximately 103 grams over the 90-day treatment period. The weight loss of the rats receiving the DRD did not appear to have become asymptotic by the end of the 90-day experiment feeding period. Upon administering 5 gram of DRD in the period of 90 days, the blood sugar level of the obese rats was reduced by 40%. The level of triglyceride in the obese rats was reduced by 90%. The level of cholesterol was reduced by approximately 60%. The level of the LDL was reduced by 70%. While the level of HDL was increased by 70%. Treatment of the obese rats with the other lipid lowering drugs in parallel with DRD demonstrated that the lipid lowering effect of DRD was better than many other lipid lowering drugs, such as resins, statins, fibrates, and niacin.
Example 2
Male and Female Wistar Rats (Hypothalamic Lesions)—2.5/5.0 Dry Herbal Administration
[0054] Male and female Wistar rats with hypothalamic lesions were made obese by providing the high caloric diet for 180 days, after which the male rats reached an average weight of about 580 grams and the female rats reached an average weight of about 430 grams. At that time, they received a daily administration of either 2.5 grams DRD or 5.0 grams DRD for 90 days by intubation (5 mL).
[0055] The male Wistar rats receiving the 2.5 grams DRD and 5.0 grams DRD lost about 36% and 41% of their pre-treatment body weight, respectively. The male obese control rats gained about 10 gram and the male normal control rats gained about 120 grams, (from a mean staring weight of approximately 423 grams), over the 90-day treatment period.
[0056] The females lost about 33% and 42% of their pre-treatment body weight when administered the 2.5 and 5.0 grams DRD, respectively. The loss of weight in both genders became asymptotic at about 45 days. The female obese controls maintained a constant weight and the female normal control rats gained about 50 grams (from a mean starting weight of approximately 350 grams) over 90-day treatment period.
Example #3
Male Wistar Rats—1.0/1.5/5:0 g Dry Herbal Administration
[0057] Young growing male Wistar rats, of about 220 grams average initial weight, were fed the obesity-inducing diet. Concomitantly, the rats were administered, 1.0 gram DRD, 1.5 grams DRD, or 5.0 grams DRD, by daily intubation, for 90 days. The treatment groups gained 21%, 24% and 47% less weight, respectively, than did the placebo controls. The rats administered fenfluramine gained 22% less weight than did the controls.
[0058] Administration of the herbal decoction of the present invention prevented weight gain in a high fat diet and a dose-dependent manner. The data and a morphological examination indicate that the rats that administered the decoction had significantly less parametrial fat than did the controls and slightly higher protein/fat ratios. Thus, the prevention of weight gain appears to be due to a reduction in fat storage, and that the skeletal muscle had been preserved. No significant adverse or side effects were observed in the rats administered the herbal decoction during the experimental period, nor was there any observed during the recovery period.
Example #4
Female Wistar Rats—Low/High Dose DRD (Aqueous Extract) 1.0/1.5/5.0 g Dry Herbal Administration
[0059] Sixty female Wistar rats, averaging 220 g in weight, were randomly allotted to five experimental groups and fed the high fat diet described in Table I below for 56 days. The rats were housed individually in wire mesh cages equipped with an automated watering system. The room housing the rats was maintained at a temperature of 22° to 24° C., with a light-dark cycle of 12 hours each. Following the one-week quarantine period the rats were adapted to handling, and to oral insertion of the gastric intubation device over the next ten days. Water was intubated once a day during this period. After ten days, the rats no longer indicated marked distress during the procedure.
TABLE I Food Ingredient Diet Composition Casein 287.0 Starch 238.0 Corn oil 32.0 Crisco shortening a 266.0 Alphacel nonnutritive bulk b 120.2 Mineral mixture (AIN-76) c 42.0 Choline 2.4 dl-Methionine 1.4 Vitamin mixture (AIN-76) d 11.0
[0060] After adaption to the intubation procedure, the diet of Table I was initiated. This diet is comprised of 56% of energy from fat. All treatment and placebo intubations occurred between 1600 and 1800 hours. Individual food intake was measured daily throughout the study. Body weight was measured daily through day 23 and twice weekly thereafter. The experimental period lasted 56 days. Lin, X., M. R. Chavex, R. C. Bruch, et al., J. Nutrition 128:1606-13, 1998.
[0061] Referring to Table II below, the five groups consisted of: the control group (n=15), which were fed ad libitum, and were intubated daily with 1 mL of water. The “low dose DRD” (n=10) and the “high dose DRD” (n=15) groups, which were fed ad libitum and administered daily 1 mL of the aqueous extract obtained from 0.75 grams and 1.50 grams of the initial dried herb mixture by intubation, respectively. The “fenfluramine group” (n=10), which was fed ad libitum and received 2 mg/kg fenfluramine in 1 mL of water daily, by intubation, and, finally, a fifth group (n=10) was pair-fed to the high dose DRD group and was administered 1 mL of water daily, by intubation.
TABLE II Starting Group n Weight, Gms Treatment C 15 218.0 ± 16.8 Control: vehicle (water) only by intubation; food and water ad libitum. L 10 214.3 ± 11.1 Low dose DRD: 1 mL water extract from 0.75 g of the dry herbal mixture by intuba- tion; food and water ad libitum H 15 226.0 ± 17.5 High dose DRD: 1 mL water extract from 1.50 g of the dry herbal mixture by intuba- tion; food and water ad libitum. FF 10 218.7 ± 18.9 Fenfluramine: d-fenfluramine in vehicle (water) at 2 mg/kg of body weight; food and water ad libitum. PF 10 218.2 ± 12.3 Pair fed: vehicle (water) only; food restricted to average of amount consumed by the H group the previous day; water ad libitum.
[0062] Food consumption for all rats was determined daily, and body weights were obtained daily for the first 23 days, and then twice a week for the next 33 days. After 56 days all the rats except five from the control group and five from the high dose DRD group were sacrificed. Trunk blood was collected, and the eviscerated carcasses were homogenized, dried and assayed for body composition. White and brown fat depots, liver, kidney, spleen, heart, and gastrocnemius muscle were weighed. During the 56 days of the experiment, all rats were observed daily by the animal technician, and weekly by a veterinarian, and notations were made regarding physical activity/lethargy, fur condition, skin condition, eye condition, stools, and “others.” There were no noticeable differences among any of the groups with regard to physical activity, skin condition, and eye condition. However, initially after intubation, the rats fed the DRD did exhibit some rubbing of the mouth and nose areas. This rubbing resulted in some alopecia. This behavior lasted about one week and then stopped. The other groups did not exhibit this rubbing.
[0063] The rats administered either dose of DRD had loose stools for the first few days. By the end of the first week the stools of the rats fed the low dose DRD were well formed and the consistency appeared normal. However, after one week the consistency of the stools of the rats fed the high dose DRD generally still appeared softer than the stools of the rats in the other groups. Soft stools were observed among the high dose DRD-treated rats from time to time during the course of the study. Additionally, the stools of both DRD groups were reddish in color, and remained so for the duration of the experiment.
[0064] The serum was analyzed for insulin, corticosterone and leptin, using standard commercially available immunoassays for the rat. Alkaline phosphatase, alanine aminotransferase, amylase, aspartate aminotransferase, chloride, cholesterol, creatinine phosphokinase, γ-glutamyl transpeptidase, glucose, hemoglobin, hematocrit, mean cell volume, platelets, potassium, sodium, triglycerides, and white blood cells were assayed by standard clinical laboratory methods. All data were pooled by treatment and subjected to a One-Way Analysis of Variance (ANOVA) followed by a Scheffe Comparison of Means analysis (for unbalanced groups). Statistix® for Windows, 1998. Analytical Software, Tallahassee, Fla. 32317.
[0065] The rats that were not sacrificed and had previously received the high dose DRD had their treatment withdrawn during a 14-day “recovery period.” On the 15 th day of this recovery period these rats, plus five control rats, were sacrificed and all the above analyses were conducted.
[0066] At time zero, the mean weights of the five groups were not different from each other. By the end of the first week the rats treated with fenfluramine had weight gain differences from the controls that would remain very consistent throughout the eight-week study (range from 14.0 to 19.6 grams). During the first half of the study, and especially during weeks two through four, the weight gain differences between the fenfluramine-treated rats and the controls paralleled those of the low dose DRD group. However, the fenfluramine weight gain differences remained constant for the remaining four weeks while the low dose DRD group substantially increased the weight gain difference from controls during this same period. The weight gain differences for the pair-fed rats mimicked those of the rats treated with high dose DRD. From the third to the eighth week the weight gain differences of the pair-fed rats ranged from 34.6 to 46.6 grams.
[0067] The data indicate that the high dose DRD treatment exerts an effect on the rats early in the treatment cycle, and that this effect remained fairly constant over the remaining course of the study. The low dose DRD rats exhibit a delay in reaching steady state in weight difference. The DRD may prevent or reduce the deposition of fat (especially in the parametrial region) in the female rat, and when a steady state is reached, this reduction remains constant throughout the study. This would account for the consistent difference in absolute weight, but not consistent differences in percent weight, seen in this study. The maximum effect of fenfluramine, although not as large as that ultimately seen with either DRD group, occurred by the end of the first week.
[0068] Referring to FIG. 1, the cumulative weight gain for each animal was determined on days 7, 14, 21, 27, 34, 41, 48 and 56 (weeks 1 through 8). At days 7 and 14, average weight gains of the rats in each of the four treatment groups were significantly less than the weight gains of the controls, but not different from each other. Statistically significant separation among the four treated groups did not occur until the 2 st day, but then this pattern was maintained for the remainder of the study. The control group gained the most weight. The weight gains for the group receiving low dose DRD and the group receiving fenfluramine were significantly less than that of the control group, but were not significantly different from each other. The weight gains for the group receiving the high dose DRD (Group 3), and the group being pair-fed to the high dose DRD group, were significantly less than the control group, the low dose DRD group, and the fenfluramine group, but not different from each other.
[0069] On the 56 th day of treatment, the rats administered low dose DRD and high dose DRD had gained 24.6% and 33.4% less weight respectively than did the control rats. The rats administered fenfluramine gained 12.3% less weight than did the controls. Changes in body weight and weight gain over the eight week experimental period for the treatment groups are shown in TABLE III, and changes in weight gain are shown in FIG. 2.
TABLE III Average Average Average Starting Weight, Final Weight, Gain, Treatment Gms ± SD. Gms ± SD. Gms ± SD Control 218.4 ± 16.8 340.3 ± 36.8 121.9 ± 25.3 d-Fenfluramine 218.7 ± 13.9 325.7 ± 33.7 106.9 ± 22.0 Low dose DRD 214.3 ± 11.1 306.2 ± 30.1 91.9 ± 29.0 High dose DRD 226.2 ± 17.7 307.4 ± 39.4 81.3 ± 26.5 Pair Fed 218.2 ± 12.3 296.9 ± 23.0 78.7 ± 18.7
[0070] The rats in the control group consumed significantly more total food than did the rats in any of the treatment groups over the 56-day period. The rats administered fenfluramine and low dose DRD consumed less total food over the 56 day period than the controls, but significantly more food than the rats fed the high dose DRD (and the rats that were pair-fed). The rats fed the high dose DRD and those that were pair fed ate significantly less total food over the 56 day period than did the other groups of rats, but the same as each other.
[0071] Weight loss due to decreased food efficiency suggests that a metabolic effect is occurring. At the end of the 56-day treatment period the control rats realized significantly greater food efficiency than did any of the treatment groups. Referring to FIG. 3, the food efficiencies of rats fed the low dose DRD and the rats fed fenfluramine, when calculated from grams of food ingested, were significantly greater than either the group in which rats were fed the high dose DRD or the group in which the rats were pair-fed. Rats fed the low dose and high dose DRD had food efficiencies that were 15.6% and 22.5% lower than controls, respectively. The food efficiency of the fenfluramine group was 7.8% lower than controls, suggesting a dose-related decrease in food efficiencies. Somewhat anomalously, the pair-fed group, which might be expected to have a higher food efficiency than fenfluramine or DRD-treated groups, had a lower food efficiency similar to that of the high dose DRD group. When food efficiency was calculated as a function of calories ingested, and requirements for basal metabolism were subtracted, differences in food efficiency existed between the groups. Pair-fed rats, fenfluramine rats, and low dose DRD rats exhibited somewhat lower food efficiencies than the controls, and the rats fed the high dose DRD had the lowest food efficiency. These differences between groups, however, did not reach statistical significance, but only reflected a trend (p=0.10).
[0072] When food efficiency was calculated as a function of mean body weight and calories consumed, calories required for maintenance were subtracted from total calories consumed, yielding calories available for gain. Referring to FIG. 4, food efficiency may be expressed as the gain in weight for each calorie available for gain above maintenance. Thus, food efficiency for the control group, the fenfluramine-treated group, the pair fed group, and the groups administered low dose DRD, high dose DRD, was 0.0584, 0.0545, 0.0539, 0.0517, and 0.0497 grams respectively, per calorie remaining after the calories required for maintenance had been met.
[0073] The control group had the highest food efficiency; requiring only 17.09 ingested calories to cause a one-gram gain in weight. This value was obtained by dividing the actual gain per day (2.18 grams) by the daily energy available for gain (37.20 calories). The groups administered low dose DRD and fenfluramine required 18.83 and 18.16 calories to cause a one-gram weight gain respectively, and thus had lower food efficiencies than the control. The group administered the high dose DRD, however, had the lowest food efficiency, requiring 19.35 calories to gain the same one-gram. The pair-fed rats required less calories than did the high dose DRD-treated group to gain the same weight. The amount of calories required by the pair-fed rats, 18.14, is similar to that required by the low dose DRD-treated and fenfluramine-treated rats.
[0074] No differences were found between the groups for any of the serum indices evaluated after the 56-day experimental period, with the exception of leptin. There is generally a direct positive correlation between the quantity of leptin in the blood and the amount of body fat and an increase in the risk of diabetes mellitus. At the end of the 56-day treatment period, the control rats had significantly more leptin in their blood than did the other treatment groups. The rats administered fenfluramine had less leptin than controls, but significantly more than the rats administered either dose of DRD or the pair-fed rats. The differences in leptin values continued during the 14-day recovery period despite the withdrawal of DRD, but this might be expected due to the modest weight gain seen during that period.
[0075] Serum insulin levels reflect the metabolic processes related to carbohydrate and fat storage and usage for energy. Corticosterone is a hormone necessary to combat stress and maintain intermediary metabolism. There were no statistical differences between the serum insulin or corticosterone levels for the controls or any of the treatment groups suggesting that the treatments did not adversely affect the rats' metabolism, nor did they cause stress.
[0076] The data demonstrate that the herbal decoction of the invention significantly reduces weight gain in growing female rats fed a high fat diet when compared to controls. The rats administered the high dose DRD and low dose DRD gained 33.4% and 24.6% less weight, respectively, than did the controls. Further, this weight reduction appears to occur in a dose-dependent manner, as shown in FIG. 5. The regression analysis of the computer-generated dose-response curve yields a relationship with a r 2 value of 0.73 and an r value of 0.85, with a significance of greater than 99%. Increasing the dosage did increase the weight difference effect. However, it appears that a dose of approximately 2.5 g of original plant material equivalent/mL is an effective and efficient dose that results in substantial differences in weight between treated and control rats.
[0077] Referring to FIG. 6A, the weight gain data for the DRD-treated male rats as a percent of control for the animals in Example 3 at 56 days was compared to the weight gain data for the DRD-treated female rats in Example 4 as a percent of control at 56 days. At 56 days the percent weight gain trends of the DRD-treated rats in both studies were similar, but the female rats in Example 4 showed greater differences from controls (gained less weight as a percent of the controls) than did the male rats in Example 3.
[0078] However, referring to FIG. 6B, when the weight gains as a percent of control weights in Example 4 were compared to later time periods of the study in Example 3, the differences from controls were similar. In Example 3, at 65 days the percent differences between the DRD-treated male rats and the controls reached the level at which they would generally remain for the duration of the 90-day study.
[0079] Referring to FIG. 7, the weight of all treated groups in Example 4 were compared to the weight of controls for weeks one through eight and the differences in absolute weight between the groups were evaluated. The data indicate that the differences in weight between the rats treated with high dose DRD and the controls increased for the first three weeks, and these differences then generally remained consistent (range of 36.9 to 46.5 grams) until the end of the study. The rats treated with low dose DRD maintained a fairly consistent difference in weight from the controls for the first four weeks (range of 11.4 to 18.8 grams). During the fifth week, however, the difference increased, and this increase remained consistent for the remaining four weeks of the study (range of 28.6 to 34.0).
[0080] Although the percent total body fat of the rats determined at the end of the study was not significantly different among any of the groups, the amount of parametrial fat in the rats administered high dose DRD was significantly less than any other group of rats. The rats administered low dose DRD and the pair-fed rats had more parametrial fat than did the high dose DRD rats, but significantly less than either the controls or the rats administered fenfluramine. Referring to FIG. 8, when body compositions, and respective grams of fat+ash, protein, water, and fat, of 220 gram rats were compared to like indices of the rats after 56 days of treatment, the control rats had gained significantly more weight as fat than did any of the other rats. The rats administered the low dose DRD and the fenfluramine gained significantly less fat than did the controls, and the rats fed the high dose DRD gained the least amount of fat and the differences were significantly different from all other groups. The gain in protein, however, was not different among any of the groups, indicating that the differences in lack of weight gain could be attributed to lack of fat gain but not lack of protein gain.
[0081] In conclusion, administration of the DRD herbal decoction significantly prevented weight gain in rats fed the high fat diets, in a dose-dependent manner. Also, the rats administered the DRD decoction had significantly less parametrial fat than did the controls. Both DRD groups also had higher protein/fat ratios than the pair fed rats and the controls, although not significantly so, indicating that the prevention of weight gain was due to a reduction in fat storage, and that the skeletal muscle had been preserved.
[0082] The reduction in weight gain experienced by the groups administered DRD also involved a reduction in food ingestion caused by a probable anorectic effect. Rats fed the low dose and high dose DRD had food efficiencies that, when measured as a function of grams of food ingested, were significantly 15.6% and 22.5% lower than controls, respectively, but were not lower than the pair-fed rats. When measured as a function of energy ingested statistical significance was not reached, but a trend (p=0.10) was observed. The control rats had the highest food efficiency (exhibited the greatest gain per calorie remaining after maintenance requirements were met). The pair-fed rats and the rats administered fenfluramine and low dose DRD were grouped together with lower food efficiencies than the controls, and the rats fed the high dose DRD had the lowest food efficiency.
[0083] There will be various modifications, improvements, and applications of the disclosed invention that will be apparent to those of skill in the art, and the present application encompasses such embodiments to the extent allowed by law. Although the present invention has been described in the context of certain preferred embodiments, the full scope of the invention is not so limited, but is in accord with the scope of the following claims. | The present invention relates to a dietary supplement for the treatment of obesity, including both weight loss and reduction of weight gain. Pursuant to the invention, a decoction of a herbal mixture, comprising rhubarb, red saga root, astragalus, turmeric, and dried ginger and various combinations thereof, provides therapeutic weight loss as well as lipid reduction and change body composition. The invention includes methods of manufacture and administration and also includes the herbal decoction in various forms of administration and in combination with food. | 0 |
This invention pertains to ball valves, and in particular to ball valve subassemblies, i.e., the operative components within ball valve housings, and to means for unitizing such operative components of ball valves into integrated assemblies.
BACKGROUND OF THE INVENTION
Typical ball valves comprise valve housings with a cover having a stem, the stem being received in an apertured ball, and the ball interposed between seat rings. The aforesaid components, seat rings and ball, set within recesses provided therefor in the housing. Too, a compression spring is emplaced about the stem, and in between the cover and the ball, and a gasket is interposed between the cover and the housing.
Some fair degree of manual dexterity is required to assemble the ball valve components within a ball valve housing. Also, it will occur that personnel sent to service such valves wear bulky protective garments and gloves, and such limit an ability to handle separate ball valve parts and components with any facility. It would be of significant advantage to have the internal, operating components of a ball valve unitized into an integrated assembly, to simplify maintenance and servicing of the valve. Particularly, it would be beneficial to be able to remove all the internal, operating components of the ball valve with the cover when it is removed, such components being an integrated unit. This can be of importance in those valve applications involving radiation or toxic media, in which the valve must be serviced by remote, manipulation devices. Remote devices can detach a cover from a housing, with some facility, albeit not separate, internal parts; consequently the benefit of having all internal, operating components unitized and removable with the cover is self-evident.
SUMMARY OF THE INVENTION
It is an object of this invention to set forth a ball valve subassembly which obviates any need for particular manual dexterity in servicing ball valves, and means for unitizing ball valve subassembly components into an integrated assembly.
Particularly, it is an object of this invention to disclose a ball valve subassembly comprising a valve cover; seat rings; an apertured ball interposed between said rings; and means, removably coupled to said cover, unitizing said rings, ball and cover into an integrated assembly.
It is also an object of this invention to set forth, for use with a ball valve subassembly which has a valve cover, seat rings, and an apertured ball interposed between said rings, means for unitizing said rings, ball and cover into an integrated assembly, comprising a U-shaped band; wherein terminal ends of said band have means for fastening thereof to the valve cover; and said band comprises means for constraining said rings, sealingly, against said ball, while holding said rings captive.
Further objects of this invention, as well as the novel features thereof, will become apparent by reference to the following description taken in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a ball valve in which an embodiment of the invention is incorporated, the valve housing being shown in cross-section, and the ball valve subassembly being shown in full line illustration;
FIG. 2 is a perspective, exploded view of the novel ball valve subassembly, according to the FIG. 1 embodiment thereof; and
FIG. 3 is a perspective illustration of the inventive ball valve subassembly of FIG. 2 in assembled, operative disposition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a ball valve 10, of the top entry type, comprises a valve housing 12 with a cover 14 which is secured to the housing (by fasteners, not shown). The cover 14 has (a) a gasket 15, which is held in a circumferential groove provided therefore in the cover 14, and (b) has a throughgoing stem 16 which is keyingly received in a hole in a ball 18, in order that the ball can be rotated due to a rotation of the stem 16. The ball 18 has a throughgoing aperture 20, along an axis 22 thereof, and is nested between a pair of seat rings 24. The seat rings 24 are received, snugly, in seating recesses 26 formed therefor in the housing 12.
FIGS. 2 and 3 show a novel band 28 which is used to unitize the rings 24 and the ball 18 into an integrated assembly with the cover 14 so that, when the cover 14 is unfastened from the housing 12, it has the band 28, rings 24 and ball 18 assembled thereto, along with a ball-biasing compression spring 30.
The band 28, of U-shape, has right-angular, footed ends 32 for fastening thereof to an inner surface 34 of the cover 14, ends 32 having fastener holes formed therein for receiving the fasteners 36. Surface 34 is drilled and tapped for reception of the fasteners 36. The band 28 has a pair of parallel straps 38 and 40. Each of the straps 38 and 40 has a pair of inturned, mutually confronting tabs 42, the same formed in the outermost ends of the band 28. The rings 24 have pairs of slots 44 formed in outer surfaces thereof, for slidable engagement with the tabs 42, whereby the rings 24 are held captive in the straps 38 and 40.
The novel ball valve subassembly 46 is assembled with the ball 18 in the valve open position (as shown in FIGS. 2 and 3). The seat rings 24 are set tightly against the opposite ends of the ball axis 22, and pushed down into the band 28 so that the slots 44 in the opposite sides of the rings 24 come into slidable engagement with the tabs 42. The spring 30 is set about the stem 16, and the footed ends 32 are secured to the cover inner surface 34 with the fasteners 36. With the subassembly 46 set into the housing 12, in the valve open position, there obtains a clearance between the seat rings 24 and the recesses 26. However, when the valve stem 16 is rotated ninety degrees of arc, to close the valve 10, the ball effects a camming action on the seat rings 24. This camming action proceeds from the provisioning of chamfers 21 about the outer surfaces or rims of the aperture 20 in the ball 18. In the open position, the seat rings 24 are held fast against the chamfers 21. As the ball 18 is rotated ninety degrees of arc, to closure, the spherical ball surfaces compress the seat rings. In this, the ball 18 pushes the rings 24 outwardly, along the axis 22, compressing the rings 24 between the ball 18 and the recesses 26, resulting in an efficient sealing off of the valve 10.
The band, in this embodiment of the invention, is formed of flexible, stainless steel. Consequently it can respond to compression of the seat rings, flexing therewith as necessary, with the valve in the closed and sealed off position. Yet, when the valve 10 is returned to a valve open position, the flexed band 28 returns to its quiescent attitude, i.e., with the aforesaid clearance between the seat rings 24 and the recesses 26. Removal of the entire, integrated subassembly 46, then, from the housing 12 is easily done.
It should be noted that, due to the slots 44 in the rings 24, and the tabs 42 on the straps 38 and 40, the rings 24 are free to move up and down, relative to the axis 22, albeit held captive by the tab 42-to-slot-44 arrangement. Thus, the rings are able to self-locate, in an optimum and correct seating thereof in the recesses 26, by sliding along the tabs 42.
While we have described the invention in connection with a specific embodiment thereof, it is to be clearly understood that this is done only by way of example, and not as a limitation to the scope of the invention, as set forth in the objects thereof and in the appended claims. | The subassembly is an integrated unit in which the operating internals of the ball valve are coupled to, and removable with, the ball valve cover. A flexible, U-shaped band, removably fastened to the cover, holds seat rings captive therein, and positions the rings at opposite, axial sides of the valve ball. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a filing under 35 U.S.C. § 371 and claims priority to international patent application number PCT/GB2005/002884 filed Jul. 22, 2005, published on Jan. 26, 2006, as WO 2006/008542, which claims priority to U.S. provisional patent application Nos. 60/590,814 filed Jul. 23, 2004, 60/645,915 filed Jan. 21, 2005 and 60/645,968 filed Jan. 21, 2005; the disclosures of which are incorporated herein by reference in their entireties.
GOVERNMENT SUPPORT
This invention was made with government support under GM052948 awarded by the NIH. The government has certain rights in the invention.
TECHNICAL FIELD
The present invention relates to cell cycle phase-specific markers and methods for determining the transition between different phases of the cell cycle in mammalian cells.
BACKGROUND OF THE INVENTION
Eukaryotic cell division proceeds through a highly regulated cell cycle comprising consecutive phases termed G1, S, G2 and M. Disruption of the cell cycle or cell cycle control can result in cellular abnormalities or disease states such as cancer which arise from multiple genetic changes that transform growth-limited cells into highly invasive cells that are unresponsive to normal control of growth. Transition of normal cells into cancer cells can arise though loss of correct function in DNA replication and DNA repair mechanisms. All dividing cells are subject to a number of control mechanisms, known as cell-cycle checkpoints, which maintain genomic integrity by arresting or inducing destruction of aberrant cells. Investigation of cell cycle progression and control is consequently of significant interest in designing anticancer drugs (Flatt, P. M. and Pietenpol, J. A. Drug Metab. Rev., (2000), 32(3-4), 283-305; Buolamwini, J. K. Current Pharmaceutical Design, (2000), 6, 379-392).
Cell cycle progression is tightly regulated by defined temporal and spatial expression, localisation and destruction of a number of cell cycle regulators which exhibit highly dynamic behaviour during the cell cycle (Pines, J., Nature Cell Biology, (1999), 1, E73-E79). For example, at specific cell cycle stages some proteins translocate from the nucleus to the cytoplasm, or vice versa, and some are rapidly degraded. For details of known cell cycle control components and interactions, see Kohn, Molecular Biology of the Cell (1999), 10, 2703-2734.
Accurate determination of cell cycle status is a key requirement for investigating cellular processes that affect the cell cycle or are dependent on cell cycle position. Such measurements are particularly vital in drug screening applications where:
i) substances which directly or indirectly modify cell cycle progression are desired, for example, for investigation as potential anti-cancer treatments; ii) drug candidates are to be checked for unwanted effects on cell cycle progression; and/or iii) it is suspected that an agent is active or inactive towards cells in a particular phase of the cell cycle.
Traditionally, cell cycle status for cell populations has been determined by flow cytometry using fluorescent dyes which stain the DNA content of cell nuclei (Barlogie, B. et al, Cancer Res., (1983), 43(9), 3982-97). Flow cytometry yields quantitative information on the DNA content of cells and hence allows determination of the relative numbers of cells in the G1, S and G2+M phases of the cell cycle. However, this analysis is a destructive non-dynamic process and requires serial sampling of a population to determine cell cycle status with time. A further disadvantage of flow cytometry techniques relates to the indirect and inferred assignment of cell cycle position of cells based on DNA content. Since the DNA content of cell nuclei varies through the cell cycle in a reasonably predictable fashion, ie. cells in G2 or M have twice the DNA content of cells in G1, and cells undergoing DNA synthesis in S phase have an intermediate amount of DNA, it is possible to monitor the relative distribution of cells between different phases of the cell cycle. However, the technique does not allow precision in determining the cell cycle position of any individual cell due to ambiguity in assigning cells to G2 or M phases and to further imprecision arising from inherent variation in DNA content from cell to cell within a population which can preclude precise discrimination between cells which are close to the boundary between adjacent phases of the cell cycle. Additionally, variations in DNA content and DNA staining between different cell types from different tissues or organisms require that the technique is optimised for each cell type, and can complicate direct comparisons of data between cell types or between experiments (Herman, Cancer (1992), 69(6), 1553-1556). Flow cytometry is therefore suitable for examining the overall cell cycle distribution of cells within a population, but cannot be used to monitor the precise cell cycle status of an individual cell over time.
EP 798386 describes a method for the analysis of the cell cycle of cell sub-populations present in heterogeneous cell samples. This method uses sequential incubation of the sample with fluorescently labelled monoclonal antibodies to identify specific cell types and a fluorochrome that specifically binds to nucleic acids. This permits determination of the cell cycle distribution of sub-populations of cells present in the sample. However, as this method utilises flow cytometry, it yields only non-dynamic data and requires serial measurements to be performed on separate samples of cells to determine variations in the cell cycle status of a cell population with time following exposure to an agent under investigation for effects on cell cycle progression.
A number of researchers have studied the cell cycle using traditional reporter enzymes that require the cells to be fixed or lysed. For example Hauser & Bauer (Plant and Soil, (2000), 226, 1-10) used β-glucuronidase (GUS) to study cell division in a plant meristem and Brandeis & Hunt (EMBO J., (1996), 15, 5280-5289) used chloramphenical acetyl transferase (CAT) fusion proteins to study variations in cyclin levels. U.S. Pat. No. 6,048,693 describes a method for screening for compounds affecting cell cycle regulatory proteins, wherein expression of a reporter gene is linked to control elements which are acted on by cyclins or other cell cycle control proteins. In this method, temporal expression of a reporter gene product is driven in a cell cycle specific fashion and compounds acting on one or more cell cycle control components may increase or decrease expression levels.
U.S. Pat. No. 6,159,691 describes nuclear localisation signals (NLS) derived from the cell cycle phase-specific transcription factors DP-3 and E2F-1 and claims a method for assaying for putative regulators of cell cycle progression. In this method, nuclear localisation signals (NLS) derived from the cell cycle phase specific transcription factors DP-3 and E2F-1 may be used to assay the activity of compounds which act to increase or decrease nuclear localisation of specific NLS sequences from DP-3 and E2F-1 fused to a detectable marker.
Jones et al (Nat. Biotech., (2004), 23, 306-312) describe a fluorescent biosensor of mitosis based on a plasma membrane targeting signal and an SV40 large T antigen NLS fused to EYFP. Throughout the cell cycle the reporter resides in the nucleus but translocates to the plasma membrane during mitosis, between nuclear envelope breakdown and re-formation.
WO 03/031612 describes DNA reporter constructs and methods for determining the cell cycle position of living mammalian cells by means of cell cycle phase-specific expression control elements and destruction control elements.
Gu et al. (Mol Biol Cell., 2004, 15, 3320-3332) have recently investigated the function of human DNA helicase B (HDHB) and shown that it is primarily nuclear in G1 and cytoplasmic in S and G2 phases, that it resides in nuclear foci induced by DNA damage, that the focal pattern requires HDHB activity, and that HDHB localization is regulated by CDK phosphorylation.
None of the preceding methods specifically describe sensors which can be stably integrated into the genome and used to indicate G1, S and G2 phases of the cell cycle. Consequently, methods are required that enable these phases of the cell cycle to be determined non-destructively in a single living mammalian cell, allowing the same cell to be repeatedly interrogated over time, and which enable the study of the effects of agents having potentially desired or undesired effects on the cell cycle. Methods are also required that permit the parallel assessment of these effects for a plurality of agents.
SUMMARY OF THE INVENTION
The present invention describes a method which utilises key components of the cell cycle regulatory machinery in defined combinations to provide novel means of determining cell cycle status for individual living cells in a non-destructive process providing dynamic read out.
The present invention further provides proteins, DNA constructs, vectors, and stable cell lines expressing such proteins, that exhibit translocation of a detectable reporter molecule in a cell cycle phase specific manner, by direct linkage of the reporter signal to a G1/S cell cycle phase dependent location control sequence. This greatly improves the precision of determination of cell cycle phase status and allows continuous monitoring of cell cycle progression in individual cells. Furthermore, it has been found that key control elements can be isolated and abstracted from functional elements of the cell cycle control mechanism to permit design of cell cycle phase reporters which are dynamically regulated and operate in concert with, but independently of, endogenous cell cycle control components, and hence provide means for monitoring cell cycle position without influencing or interfering with the natural progression of the cell cycle.
According to a first aspect of the present invention, there is provided a polypeptide construct comprising a detectable live-cell reporter molecule linked via a group having a molecular mass of less than 112,000 Daltons to at least one cell cycle phase-dependent location control element, the location of which said element changes during G1 and S phase, wherein the translocation of said construct within a mammalian cell is indicative of the cell cycle position.
It will be understood that translocation is defined as the detectable movement of the reporter from one sub-cellular location to another, typically from the nucleus to the cytoplasm or vice versa. It will be further understood that the term ‘live cell’, as it relates to a reporter molecule, defines a reporter molecule which produces a detectable signal in living cells, or a reporter, such as an antigenic tag, that is expressed in living cells and can be detected after fixation through immunological methods, and is thus suitable for use in imaging systems, such as the IN Cell Analyzer (GE Healthcare).
Suitably, said group has a molecular mass of less than 100,000 Daltons.
Suitably, the group has a molecular mass of less than 50,000 Daltons.
Suitably, the group has a molecular mass of less than 25,000 Daltons.
Suitably, the group has a molecular mass of less than 10,000 Daltons.
Suitably, the group has a molecular mass of less than 1,000 Daltons.
Suitably, the group has a molecular mass of less than 700 Daltons.
Suitably, the group has a molecular mass of less than 500 Daltons.
Preferably, the group is a polypeptide. The polypeptide group should be relatively small and comprise amino acids that allow flexibility and/or rotation of the reporter molecule relative to the cell cycle phase-dependent location control element. More preferably, the polypeptide group is a heptapeptide. Most preferably, said heptapeptide group is Gycine-Asparagine-Glycine-Glycine-Asparagine-Alanine-Serine (GNGGNAS; SEQ ID NO: 18). As stated above, any amino acids which allow flexibility and/or rotation of the reporter molecule relative to the location control element may be used in the polypeptide.
Suitably, the cell cycle phase-specific dependent location control element is selected from the group of peptides consisting of Rag2, Chaf1B, Fen1, PPP1R2, helicase B, sgk, CDC6 or motifs therein such as the phosphorylation-dependent subcellular localization domain of the C-terminal special control region of helicase B (PSLD). Helicase B is known to cause uncontrolled DNA licensing and may be detrimental to cell survival when over-expressed. Therefore, preferably, the cell cycle phase-dependent location control element is the phosphorylation-dependent subcellular localization domain of the C-terminal spacial control region of helicase B (PSLD).
A human helicase B homolog has been reported and characterised ((Taneja et al J. Biol. Chem., (2002), 277, 40853-40861); the nucleic acid sequence (NM 033647) and the corresponding protein sequence are given in SEQ ID No. 1 and SEQ ID No. 2, respectively. The report demonstrates that helicase activity is needed during G1 to promote the G1/S transition. Gu et al (Mol. Biol. Cell., (2004), 15, 3320-3332) have shown that a small C-terminal region of the helicase B gene termed the phosphorylation-dependent subcellular localization domain (PSLD) is phosphorylated by Cdk2/cyclin E and contains NLS and NES sequences. Gu et al (Mol. Biol. Cell., (2004), 15, 3320-3332) carried out studies on cells that had been transiently transfected with plasmid encoding an EGFP-βGal-PSLD fusion (beta-galactosidase (βgal) was included in the construct as an inert group to make the whole fusion protein similar in size to the complete helicase B) expressed from a CMV promoter. Cells in G1 exhibited EGFP signal predominantly in the nucleus, whilst cells in other phases of the cell cycle exhibited predominantly cytoplasmic EGFP signal. These researchers concluded that the PSLD was directing translocation of the reporter from the nucleus to the cytoplasm around the G1/S phase transition of the cell cycle.
Suitably, the live-cell reporter molecule is selected from the group consisting of fluorescent protein, enzyme and antigenic tag. Preferably, the fluorescent protein is derived from Aequoria Victoria, Renilla reniformis or other members of the classes Hydrozoa and Anthozoa (Labas et al., Proc. Natl. Acad. Sci, (2002), 99, 4256-4261). More preferably, the fluorescent protein is EGFP (BD Clontech), Emerald (Tsien, Annu. Revs. Biochem., (1998), 67, 509-544) or J-Red (Evrogen). Most preferably, the fluorescent protein is selected from the group consisting of Green Fluorescent Protein (GFP), Enhanced Green Fluorescent Protein (EGFP), Emerald and J-Red.
Suitably, the reporter is an enzyme reporter such as halo-tag (Promega).
Suitably, the reporter molecule is EGFP or J-Red and the cell cycle phase-dependent location control element is PSLD.
Suitably, the reporter molecule is tandemized (i.e. present as a tandem repeat).
A polypeptide construct comprising the amino acid sequence of SEQ ID No. 5.
According to a second aspect of the present invention, there is provided a nucleic acid construct encoding any of the polypeptide constructs as hereinbefore described.
Suitably, said nucleic acid construct additionally comprises and is operably linked to and under the control of at least one cell cycle independent expression control element.
The term, ‘operably linked’ indicates that the elements are arranged so that they function in concert for their intended purposes, e.g. transcription initiates in a promoter and proceeds through the DNA sequence coding for the reporter molecule of the invention.
Suitably, the expression control element controls transcription over an extended time period with limited variability in levels of transcription throughout the cell cycle. Preferably, the expression control element is the ubiquitin C or CMV I/E promoter which provide transcription over an extended period which is required for the production of stable cell lines.
Preferably, the nucleic acid construct comprises a Ubiquitin C promoter, and sequences encoding PSLD and EGFP or J-Red.
Optionally, the nucleic acid construct comprises a CMV promoter, and sequences encoding PSLD and EGFP or J-Red.
In a third aspect of the present invention, there is provided a vector comprising any of the nucleic acid constructs as hereinbefore described. Suitably, said vector is either a viral vector or a plasmid. Suitably, said viral vector is an adenoviral vector or a lentiviral vector.
Optionally, the vector additionally contains a drug resistance gene that is functional in eukaryotic cells, preferably a drug resistance gene that is functional in mammalian cells.
Expression vectors may also contain other nucleic acid sequences, such as polyadenylation signals, splice donor/splice acceptor signals, intervening sequences, transcriptional enhancer sequences, translational enhancer sequences and the like. Optionally, the drug resistance gene and reporter gene may be operably linked by an internal ribosome entry site (IRES), (Jang et al., J. Virology, (1988), 62, 2636-2643) rather than the two genes being driven by separate promoters. The pIRES-neo and pIRES vectors commercially available from Clontech may be used.
In a fourth aspect of the present invention, there is provided a host cell transfected with a nucleic acid construct as hereinbefore described. The host cell into which the construct or the expression vector containing such a construct is introduced may be any mammalian cell which is capable of expressing the construct.
The prepared DNA reporter construct may be transfected into a host cell using techniques well known to the skilled person. These techniques may include: electroporation (Tur-Kaspa et al, Mol. Cell. Biol. (1986), 6, 716-718), calcium phosphate based methods (eg. Graham and Van der Eb, Virology, (1973), 52, 456-467), direct microinjection, cationic lipid based methods (eg. the use of Superfect (Qiagen) or Fugene6 (Roche) and the use of bombardment mediated gene transfer (Jiao et al, Biotechnology, (1993), 11, 497-502). A further alternative method for transfecting the DNA construct into cells, utilises the natural ability of viruses to enter cells. Such methods include vectors and transfection protocols based on, for example, Herpes simplex virus (U.S. Pat. No. 5,288,641), cytomegalovirus (Miller, Curr. Top. Microbiol. Immunol., (1992), 158, 1), vaccinia virus (Baichwal and Sugden, 1986, in Gene Transfer, ed. R. Kucherlapati, New York, Plenum Press, p 117-148), and adenovirus and adeno-associated virus (Muzyczka, Curr. Top. Microbiol. Immunol., (1992), 158, 97-129).
Examples of suitable recombinant host cells include HeLa cells, Vero cells, Chinese Hamster ovary (CHO), U2OS, COS, BHK, HepG2, NIH 3T3 MDCK, RIN, HEK293 and other mammalian cell lines that are grown in vitro. Preferably the host cell is a human cell. Such cell lines are available from the American Tissue Culture Collection (ATCC), Bethesda, Md., U.S.A. Cells from primary cell lines that have been established after removing cells from a mammal followed by culturing the cells for a limited period of time are also intended to be included in the present invention.
In a preferred embodiment, the cell line is a stable cell line comprising a plurality of host cells according to the fourth aspect.
Cell lines which exhibit stable expression of a cell cycle position reporter may also be used in establishing xenografts of engineered cells in host animals using standard methods. (Krasagakis, K. J et al, Cell Physiol., (2001), 187(3), 386-91; Paris, S. et al, Clin. Exp. Metastasis, (1999), 17(10), 817-22). Xenografts of tumour cell lines engineered to express cell cycle position reporters will enable establishment of model systems to study tumour cell division, stasis and metastasis and to screen new anticancer drugs.
In a fifth aspect of the present invention, there is provided the use of a polypeptide as hereinbefore described for determining the cell cycle position of a mammalian cell.
Use of engineered cell lines or transgenic tissues expressing a cell cycle position reporter as allografts in a host animal will permit study of mechanisms affecting tolerance or rejection of tissue transplants (Pye & Watt, J. Anat., (2001), 198 (Pt 2), 163-73; Brod, S. A. et al, Transplantation (2000), 69(10), 2162-6).
According to a sixth aspect of the present invention, there is provided a method for determining the cell cycle position of a mammalian cell, said method comprising:
a) expressing in a cell a nucleic acid construct as hereinbefore described; and b) determining the cell cycle position by monitoring signals emitted by the reporter molecule.
To perform the method for determining the cell cycle position of a cell according to the sixth aspect, cells transfected with the DNA reporter construct may be cultured under conditions and for a period of time sufficient to allow expression of the reporter molecule at a specific stage of the cell cycle. Typically, expression of the reporter molecule will occur between 16 and 72 hours post transfection, but may vary depending on the culture conditions. If the reporter molecule is based on a green fluorescent protein sequence the reporter may take a defined time to fold into a conformation that is fluorescent. This time is dependent upon the primary sequence of the green fluorescent protein derivative being used. The fluorescent reporter protein may also change colour with time (see for example, Terskikh, Science, (2000), 290, 1585-8) in which case imaging is required at specified time intervals following transfection.
If the reporter molecule produces a fluorescent signal in the method of the sixth aspect, either a conventional fluorescence microscope, or a confocal based fluorescence microscope may be used to monitor the emitted signal. Using these techniques, the proportion of cells expressing the reporter molecule, and the location of the reporter can be determined. In the method according to the present invention, the fluorescence of cells transformed or transfected with the DNA construct may suitably be measured by optical means in for example; a spectrophotometer, a fluorimeter, a fluorescence microscope, a cooled charge-coupled device (CCD) imager (such as a scanning imager or an area imager), a fluorescence activated cell sorter, a confocal microscope or a scanning confocal device, where the spectral properties of the cells in culture may be determined as scans of light excitation and emission.
In the embodiment of the invention wherein the nucleic acid reporter construct comprises a drug resistance gene, following transfection and expression of the drug resistance gene (usually 1-2 days), cells expressing the modified reporter gene may be selected by growing the cells in the presence of an antibiotic for which transfected cells are resistant due to the presence of a selectable marker gene. The purpose of adding the antibiotic is to select for cells that express the reporter gene and that have, in some cases, integrated the reporter gene, with its associated promoter, into the genome of the cell line. Following selection, a clonal cell line expressing the construct can be isolated using standard techniques. The clonal cell line may then be grown under standard conditions and will express reporter molecule and produce a detectable signal at a specific point in the cell cycle.
Cells transfected with the nucleic acid reporter construct according to the present invention may be grown in the absence and/or the presence of a test agent to be studied and whose effect on the cell cycle of a cell is to be determined. By determining the proportion of cells expressing the reporter molecule and the localisation of the signal within the cell, it is possible to determine the effect of a test agent on the cell cycle of the cells, for example, whether the test system arrests the cells in a particular stage of the cell cycle, or whether the effect is to speed up or slow down cell division.
Thus, according to a seventh aspect of the present invention, there is provided a method of determining the effect of a test agent on the cell cycle position of a mammalian cell, the method comprising:
a) expressing in the cell in the absence and in the presence of the test agent a nucleic acid reporter construct as hereinbefore described; and b) determining the cell cycle position by monitoring signals emitted by the reporter molecule wherein a difference between the emitted signals measured in the absence and in the presence of the test agent is indicative of the effect of the test agent on the cell cycle position of the cell.
The term ‘test agent’ should be construed as a form of electromagnetic radiation or as a chemical entity. Preferably, the test agent is a chemical entity selected from the group consisting of drug, nucleic acid, hormone, protein and peptide. The test agent may be applied exogenously to the cell or may be a peptide or protein that is expressed in the cell under study.
In an eighth aspect of the present invention, there is provided a method of determining the effect of a test agent on the cell cycle position of a mammalian cell, the method comprising:
a) expressing in said cell in the presence of said test agent a nucleic acid reporter construct as hereinbefore described; b) determining the cell cycle position by monitoring signals emitted by the reporter molecule, and c) comparing the emitted signal in the presence of the test agent with a known value for the emitted signal in the absence of the test agent;
wherein a difference between the emitted signal measured in the presence of the test agent and the known value in the absence of the test agent is indicative of the effect of the test agent on the cell cycle position of the cell.
In a ninth aspect of the present invention, there is provided a method of determining the effect of a test agent on the cell cycle position of a mammalian cell, the method comprising:
a) providing cells containing a nucleic acid reporter construct as hereinbefore described; b) culturing first and second populations of the cells respectively in the presence and absence of a test agent and under conditions permitting expression of the nucleic acid reporter construct; and c) measuring the signals emitted by the reporter molecule in the first and second cell populations;
wherein a difference between the emitted signals measured in the first and second cell populations is indicative of the effect of the test agent on the cell cycle position of the cell.
According to a tenth aspect of the present invention, there is provided a method of determining the effect of the mammalian cell cycle on a cellular process measurable by a first detectable reporter which is known to vary in response to a test agent, the method comprising:
a) expressing in the cell in the presence of the test agent a second nucleic acid reporter construct as hereinbefore described; b) determining the cell cycle position by monitoring signals emitted by the second reporter molecule; and c) monitoring the signals emitted by the first detectable reporter,
wherein the relationship between cell cycle position determined by step b) and the signal emitted by the first detectable reporter is indicative of whether or not said cellular process is cell cycle dependent.
In an eleventh aspect of the present invention, there is provided the use of a polypeptide as hereinbefore described for measuring CDK2 activity in a cell.
According to a twelfth aspect of the present invention, there is provided a method for measuring CDK2 activity in a cell, said method comprising the steps of
a) expressing a nucleic acid construct in a cell as hereinbefore described’ and b) determining CDK2 activity by monitoring signals emitted by the reporter molecule.
According to a thirteenth aspect of the present invention, there is provided a method for determining the effect of a test agent on CDK2 activity of a mammalian cell, said method comprising:
a) expressing in said cell in the absence and in the presence of said test agent a nucleic acid construct as hereinbefore described; and b) determining CDK2 activity by monitoring signals emitted by the reporter molecule wherein a difference between the emitted signals measured in the absence and in the presence of said test agent is indicative of the effect of the test agent on the activity of CDK2.
In a fourteenth aspect of the present invention, there is provided a method of determining the effect of a test agent on CDK2 activity of a mammalian cell, said method comprising:
a) expressing in said cell in the presence of said test agent a nucleic acid construct as hereinbefore described; and b) determining the cell cycle position by monitoring signals emitted by the reporter molecule, c) comparing the emitted signal in the presence of the test agent with a known value for the emitted signal in the absence of the test agent;
wherein a difference between the emitted signal measured in the presence of the test agent and said known value in the absence of the test agent is indicative of the effect of the test agent on the CDK2 activity of the cell.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the localisation of HDHB in the nucleus or cytoplasm.
(A) Cytoplasmic and nuclear extracts of U2OS cells were analyzed by denaturing gel electrophoresis and western blotting with antibody against recombinant HDHB, α-tubulin, and PCNA. Immunoreactive proteins were detected by chemiluminescence.
(B) GFP-tagged HDHB microinjected and transiently expressed in U2OS cells were visualized by fluorescence microscopy. Nuclei were stained with Hoechst dye. Bar, 10 μm.
(C) FLAG-tagged HDHB microinjected and transiently expressed in U2OS cells were visualized by fluorescence microscopy.
FIG. 2 is the subcellular localization of GFP-HDHB is cell cycle-dependent.
(A) Subcellular localization of transiently expressed GFP-tagged HDHB in asynchronous, G1, and S phase U2OS cells was quantified. The number of GFP-positive cells with a given distribution pattern was expressed as a percentage of the total number of GFP-positive cells (>100 cells).
(B) Cytoplasmic and nuclear extracts of synchronized U2OS cells (G1 and S phase) were analyzed by denaturing gel electrophoresis and western blotting with antibody against recombinant HDHB, α-tubulin, and PCNA. Immunoreactive proteins were detected by chemiluminescence.
FIG. 3 is the identification of a domain required for nuclear localization of HDHB.
(A) Schematic representation of the HDHB protein showing seven potential phosphorylation sites for CDK (SP or TP), the putative subcellular localization domain (SLD) and phosphorylated SLD (PSLD), the Walker A and Walker B helicase motifs. Amino acid residue numbers are indicated below protein.
(B) GFP- and FLAG-tagged HDHB and C-terminal truncation mutants generated in study. The C terminus of HDHB SLD (residues 1040-1087) and PSLD (residues 957-1087) was fused to a GFP-βGal reporter to create GFP-β Gal-SLD and GFP-β Gal-PSLD respectively.
(C) The subcellular localization of transiently expressed GFP-HDHB-•SLD in asynchronous, G1, and S phase U2OS cells was quantified and expressed as a percentage of the total number of GFP-positive cells.
FIG. 4 is the GFP-β Gal-PSLD subcellular localization pattern varies with the cell cycle.
(A) The subcellular localization of transiently expressed GFP-β Gal, GFP-β Gal-SLD, and GFP-β Gal-PSLD in asynchronous, G1, and S phase U2OS cells was quantified and expressed as a percentage of the total number of GFP-positive cells.
FIG. 5 is the identification of a functional rev-type nuclear export signal (NES) in SLD of HDHB.
(A) Alignment of the putative NES in HDHB with those identified in other cell cycle-related proteins (Henderson and Eleftheriou, 2000; Fabbro and Henderson, 2003). Superscripts above the amino acid sequence indicate residue numbers. Thick arrows point to the conserved aliphatic residues in the NES. Two pairs of residues in the putative NES in HDHB were mutated to alanine as indicated by the thin arrows to create Mut1 and Mut2. HIV Rev: SEQ ID NO: 7; hBRCA1: SEQ ID NO: 8; IkBα: SEQ ID NO: 9; MAPKK: SEQ ID NO: 10; PKI: SEQ ID NO: 11; RanBP1: SEQ ID NO: 12; p 53 cNES: SEQ ID NO: 13; 14-3-3: SEQ ID NO: 14; hdm2: SEQ ID NO: 15; MDHB: SEQ ID NO: 16; HDHB: SEQ ID NO: 17.
(B) GFP- and FLAG-tagged HDHB were transiently expressed in asynchronously growing U2OS cells with (+) or without (−) LMB to inhibit CRM1-mediated nuclear export. The subcellular localization of GFP-HDHB and FLAG-HDHB in asynchronous, G1, and S phase cells was quantified and expressed as a percentage of the total number of GFP-positive cells in that sample.
(C) The subcellular localization of wild type and mutant GFP-HDHB and GFP-β Gal-PSLD in asynchronous U2OS cells was quantified and expressed as a percentage of the total number of GFP-positive cells in that sample.
FIG. 6 is the cell cycle-dependent phosphorylation of FLAG-HDHB in vivo.
(A) U2OS cells transiently expressing FLAG-HDHB (lane 1) and its truncation mutants 1-1039 (lane 2) and 1-874 (lane 3) were labeled with [ 32 P] ortho-phosphate. Cell extracts were immunoprecipitated with anti-FLAG resin. The precipitated proteins were separated by 7.5% SDS-PAGE, transferred to a PVDF membrane, and detected by autoradiography (top) or western blotting (bottom). The positions of marker proteins of known molecular mass are indicated at the left.
(B) FLAG-HDHB expressed in U2OS cells was immunoprecipitated with anti-FLAG resin, incubated with (+) or without (−)-phosphatase (-PPase) in the presence (+) or absence (−) of phosphatase inhibitors, as indicated, and analyzed by SDS-PAGE and immunoblotting with anti-HDHB antibody.
(C) U2OS cells expressing FLAG-HDHB were arrested at G1/S (top) or at G2/M(bottom), and then released from the block. FLAG-HDHB was harvested at the indicated time points, immunoprecipitated with anti-FLAG resin, treated with (+) or without (−) -PPase, and analyzed as in (B).
FIG. 7 is the identification of S967 as a major in vivo phosphorylation site in HDHB.
(A) Phosphoamino acid markers (left) and phosphoamino acids from in vivo 32P-labeled FLAG-HDHB (right) were separated in two dimensions and visualized by autoradiography. Some incompletely hydrolyzed phosphopeptides remained near the origin (+).
(B) Wild type and mutant FLAG-HDHB proteins were radiolabeled with orthophosphate in vivo, immunoprecipitated, separated by SDS-PAGE, and analyzed by autoradiography (top) and immunoblotting with anti-HDHB (bottom).
(C) Tryptic phosphopeptides of 32P-labeled wild type and S967A mutant FLAG-HDHB were separated in two dimensions and visualized by autoradiography.
FIG. 8 is the identification of cyclin E/CDK2 as the potential G1/S kinase of HDHB S967.
(A) Tryptic phosphopeptides from FLAG-HDHB phosphorylated in vivo as in FIG. 7C , or recombinant HDHB phosphorylated in vitro by purified cyclin E/CDK2 or cyclin A/CDK2, were separated in two dimensions, either individually or as a mixture, and visualized by autoradiography.
(B) Proteins that co-immunoprecipitated with FLAG vector (lanes 1, 4) or FLAG-HDHB (lanes 2, 5) expressed in U2OS cells were analyzed by immunoblotting with antibodies against HDHB (lanes 1-6), cyclin E (lanes 1-3), or cyclin A (lanes 4-6). One tenth of the cell lysate used for immunoprecipitation was analyzed in parallel as a positive control (lanes 3, 6).
FIG. 9 is the subcellular localization of HDHB is regulated by phosphorylation of S967.
(A) Subcellular localization of GFP-HDHB S967A and S967D expressed in asynchronous, G1, and S phase U2OS cells was quantified.
FIG. 10 is the localisation of EGFP-PSLD in asynchronous U2OS cells exhibiting stable expression of the pCORON1002-EGFP-C1-PSLD vector is cell cycle dependent. Fluorescence microscopy of the same partial field of cells in which (A) nuclei were stained with Hoechst dye, (B) EGFP-PSLD was visualised, (C) nuclei were exposed to BrdU for 1 hour exposure prior to fixation and detection with Cy-5 labelled antibody to indicate cells in S-phase. (D) A graph of nuclear fluorescent intensity in both the red (Cy-5 immunofluorescent detection of BrdU) and green (EGFP-PSLD) for individual cells present in a full field of view.
FIG. 11 is the vector map of pCORON1002-EGFP-C1-PSLD.
FIG. 12 is the vector map of pCORON1002-EGFP-C1-βGal-PSLD
FIG. 13 is the flow cytometry data comparing brightness and homogeneity of signal for representative stable cell lines developed with pCORON1002-EGFP-C1-PSLD, pCORON1002-EGFP-C1-Gal-PSLD and the parental U2OS cell line.
DETAILED DESCRIPTION OF THE INVENTION
Methods
Plasmids
pGFP-HDHB and mutant derivatives (see FIGS. 4 and 6 ) were created by inserting full-length HDHB cDNA as a BglII/NotI fragment (Taneja et al., J. Biol. Chem., (2002) 277, 40853-40861) into the NotI site of the pEGFP-C1 vector (Clontech, Palo Alto, Calif.). pFLAG-HDHB was constructed by inserting a HindIII/NotI fragment containing full-length HDHB cDNA into the NotI site of pFlag-CMV2 vector (Eastman Kodak Co., Rochester, N.Y.). Tagged HDHB-SLD (1-1039) was constructed by cleaving the tagged HDHB plasmid with NruI following the coding sequence for residue 1034 and with NotI in the polylinker and replacing the small fragment by a duplex adaptor oligonucleotide with a blunt end encoding residues 1035 to 1039, a stop codon, and an overhanging NotI-compatible 5′ end. To create pFLAG-HDHB (1-874), StuI-digested pFLAG-HDHB DNA was treated with Klenow polymerase to generate blunt ends and ligated into the pFLAG-CMV2 vector. To generate pEGFP-βGal, a DNA fragment encoding E. coli β-galactosidase (βGal) was amplified by PCR from pβGal-control (Clontech) and inserted at the 3′ end of the GFP coding sequence in pEGFP-C1, using the HindIII site. The HDHB sequence for amino acid residues 1040-1087(SLD) and 957-1087(PSLD) were PCR amplified and inserted at the 3′ end of the βGal cDNA in pEGFP-βGal to create pGFP-βGal-SLD and pGFP-βGal-PSLD respectively. The NES mutants and phosphorylation site mutants were created in the HDHB cDNA by site-directed mutagenesis (QuikChange, Stratagene, La Jolla, Calif.).
pCORON1002-EGFP-C1-PSLD was constructed by PCR amplification of the 390 bp PSLD region from the DNA construct pGFP-CI-Gal-PSLD. Introduction of 5′ NheI and 3′ SalI restriction enzyme sites to the PSLD fragment allowed sub-cloning into the vector pCORON1002-EGFP-C1 (GE Healthcare, Amersham, UK). The resulting 6704 bp DNA construct pCORON1002-EGFP-C1-PSLD, contains an ubiquitin C promoter, a bacterial ampicillin resistance gene and a mammalian neomycin resistance gene ( FIG. 11 ). The nucleic acid sequence of the vector is shown in SEQ ID No. 3. Three further versions of this vector were created using standard cloning techniques (Sambrook, J. et al (1989)); the EGFP gene was first replaced with J-Red (Evrogen), the neomycin resistance gene was replaced with hygromycin resistance gene and the ubiquitin C promoter was replaced with the CMV I/E promoter. pCORON1002-EGFP-C1-Gal-PSLD was constructed by NheI and XmaI restriction enzyme digest of pEGFP-CI-Gal-PSLD and insertion of the 4242 bp EGFP-Gal-PSLD fragment into pCORON1002 vector (GE Healthcare). The resulting 9937 bp DNA construct pCORON1002-EGFP-C1-Gal-PSLD ( FIG. 12 ) contains an ubiquitin C promoter, a bacterial ampicillin resistance gene and a mammalian neomycin resistance gene. The nucleic acid sequence of the vector is shown in SEQ ID No. 4.
The protein and nucleic acid sequence for the EGFP-PSLD fusion protein are shown in SEQ ID No. 5 and 6, respectively.
The correct DNA sequence of all constructs and substitution mutations was confirmed by DNA sequencing.
Antibodies
Anti-HDHB antibody was generated against purified recombinant HDHB (Bethyl Laboratories, Montgomery, Tex.) and affinity-purified on immobilized HDHB (Harlow & Lane, Antibodies; A laboratory manual. Cold Spring Harbor Laboratory).
Cell Culture, Synchronization, Microinjection, Electroporation, Transfection and Stable Cell Line Generation
U2OS cells were cultured as exponentially growing monolayers in Dulbecco-modified Eagle medium (DMEM) (Gibco BRL Lifetechnologies, Carlsbad, Calif.) supplemented with 10% fetal bovine serum (FBS) (Atlanta Biologicals, Norcross, Ga.) at 37° C. Exponentially growing U2OS cells were arrested at G1/S by incubation in DMEM containing 5 mM thymidine (Sigma-Aldrich, St. Louis, Mo.), for 24 h. To release the cells into S phase, the medium was aspirated and the cells washed three times with warm DMEM plus 10% FBS, and incubated in fresh DMEM plus 10% FBS. Exponentially growing U2OS cells were arrested in G2/M for 16 h in DMEM containing 30 ng/ml nocodazole (Sigma-Aldrich). To release cells into G1, mitotic cells were collected by gently shaking them off, washed three times with DMEM plus 10% FBS, and then plated on glass coverslips for microinjection, or in culture dishes for further manipulation.
Cell cycle synchronization was verified by flow cytometry as described previously (Taneja et al., J. Biol. Chem., (2002) 277, 40853-40861). In experiments to block nuclear protein export, cells were cultured for 3 h in DMEM containing 10 ng/ml of leptomycin B (LMB) and 10 μM cycloheximide (Calbiochem, San Diego, Calif.) to prevent new protein synthesis. Cells plated on glass coverslips were microinjected as described (Herbig et al., 1999) except that plasmid DNA rather than protein was injected.
For electroporation, asynchronously growing U2OS cells (5×106) were trypsinized, collected by centrifugation, and resuspended in 800 μl of 20 mM HEPES (pH 7.4), 0.7 mM Na2HPO4/NaH2PO4, 137 mM NaCl, 5 mM KCl, 6 mM glucose at a final pH of 7.4. Ten μg of DNA was added, transferred to a 0.4 cm electroporation cuvette (BioRad, Hercules, Calif.) and electroporation performed using Gene Pulser II apparatus (BioRad). Cells were plated in tissue culture dishes for 1 h, washed with fresh medium and cultured for another 23 h.
Working with transiently transfected cells proved difficult in multiwell plate format due to low transfection efficiency, heterogeneity of expression and problems arising from the high throughput analysis of such data. Screening for the effects of large numbers of siRNA or agents upon the cell cycle therefore required production of a homogenous stable cell line. Due to the toxic effects of HDHB when overexpressed for long periods a stable cell line was generated with the PSLD region linked to a reporter. U-2OS cells were transiently transfected with pCORON1002-EGFP-C1-PSLD ( FIG. 11 ), pCORON1002-EGFP-C1-Gal-PSLD ( FIG. 12 ) or J-Red derivatives of the above vectors. Stable clones expressing the recombinant fusion proteins were selected using 1 mg/ml G418 (Sigma) or hygromycin, where appropriate. Isolated primary clones (˜60 per construct) were analysed by flow cytometry to confirm the level and homogeneity of expression of the sensor and where appropriate secondary clones were developed using methods above.
Fluorescence Microscopy
For indirect immunofluorescence staining, cells were washed three times with phosphate buffered saline (PBS), fixed with 3.7% formaldehyde in PBS for 20 min, permeabilized for 5 min in 0.2% Triton X-100, and incubated with 10% FBS in PBS for 45 min. FLAG-HDHB was detected with mouse monoclonal anti-FLAG antibody (Sigma-Aldrich), 1:100 in PBS plus 10% FBS for 2 h at room temperature. After washing, cells were incubated with Texas Red-conjugated goat anti-mouse secondary antibody (Jackson ImmunoResearch Laboratories, West Grove, Pa.) at 1:100 in PBS plus 10% FBS for 1 h at room temperature. After three washes, cells were incubated for 10 min with Hoechst 33258 (2 μM in PBS). Coverslips were mounted in ProLong Antifade (Molecular Probes, Eugene, Oreg.). Images were obtained with a Hamamatsu digital camera using the Openlab 3.0 software (Improvision, Lexington, Mass.) on the Zeiss Axioplan 2 Imaging system (Carl Zeiss Inc.). The number of cells that exhibited each pattern of subcellular localization was counted and expressed as a percentage of the total number of cells scored (100 to 150 cells in each experiment). The subcellular distribution of each protein was quantitatively evaluated in at least two independent experiments.
For GFP fluorescence, cells were washed three times with phosphate-buffered saline (PBS), fixed with 3.7% formaldehyde containing 2 μM Hoechst 33258 for 20 min and imaged and evaluated as above.
For Triton X-100 extraction, cells were washed twice with cold cytoskeleton buffer (CSK, 10 mM HEPES [pH 7.4], 300 mM sucrose, 100 mM NaCl, 3 mM MgCl2), and extracted for 5 min on ice with 0.5% Triton X-100 in CSK buffer (supplemented with 1X protease inhibitors) and then fixed as described above.
Where appropriate, for high throughput imaging, kinetic imaging (24 hr) and analysis in multiwell plate format of stable cell lines flourescence microscopy was conducted using a high throughput confocal imaging system (IN Cell Analyzer 1000 or IN Cell Analyzer 3000, GE Healthcare, Amersham, UK) on cells transfected with pCORON1002-EGFP-C1-PSLD, pCORON1002-EGFP-C1-Gal-PSLD or redFP derivatives of these vectors. Images were analysed using the cell cycle phase marker algorithm (GE Health Care).
Metabolic Phosphate Labeling
U2OS cells (2.5×106) were transiently transfected with wild type or mutant FLAGHDHB. After 24 h, cells were incubated in phosphate-depleted DMEM (Gibco BRL Lifetechnologies) for 15 min and radiolabeled with 32P-H3PO4 (0.35 mCi/ml of medium; ICN Pharmaceuticals Inc., Costa Mesa, Calif.) for 4 h. Phosphate-labeled FLAG-HDHB was immunoprecipitated from extracts, separated by 7.5% SDS/PAGE, and transferred to a polyvinylidene difluoride (PVDF) membrane as described below.
Cell Extracts, Immunoprecipitation, and Western Blotting
At 24 h after transfection, FLAG-HDHB-transfected cultures to be analyzed by immunoprecipitation and immunoblotting were lysed in lysis buffer (50 mM Tris-HCl pH 7.5, 10% glycerol, 0.1% NP-40, 1 mM DTT, 25 mM NaF, 100 μg/ml PMSF, 1 μg/ml aprotinin, 1 μg/ml leupeptin) (0.5 ml per 35 mm or 1 ml per 60 mm dish or 75 cm flask). The extract was scraped off the dish, incubated for 5 min on ice, and centrifuged for 10 min at 14 000 g. Samples of the supernatant (0.5 to 1 mg of protein) were incubated with 10 μl anti-FLAG agarose (Sigma) on a rotator for 2 h at 4° C. The agarose beads were washed three times with lysis buffer. Immunoprecipitated proteins were transferred to a PVDF membrane and analyzed by western blotting with anti-HDHB-peptide serum (1:5000), anti-cyclin E antibody (1:1000), and anticyclin A antibody (1:1000) (Santa Cruz Biotechnology Inc., Santa Cruz, Calif.), and chemiluminescence (SuperSignal, Pierce Biotechnology Inc., Rockford, Ill.).
For selective nuclear and cytoplasmic protein extraction, 80-90% confluent U2OS cells were harvested by trypsinization and washed with PBS. They were resuspended and lysed in 10 mM Tris-HCl [pH 7.5], 10 mM KCl, 1.5 mM MgCl2, 0.25 M sucrose, 10% glycerol, 75 μg/ml digitonin, 1 mM DTT, 10 mM NaF, 1 mM Na3VO4, 100 μg/ml PMSF, 1 μg/ml aprotinin, and 1 μg/ml leupeptin for 10 min on ice, and centrifuged at 1000×g for 5 min. The supernatant fraction was collected as the cytosolic extract. The pellet was washed, resuspended in high salt buffer (10 mM Tris-HCl [pH 7.5], 400 mM NaCl 1 mM EDTA, 1 mM EGTA, 1 mM DTT, 1% NP-40, 100 μg/ml PMSF, 1 μg/ml aprotinin, and 1 μg/ml leupeptin), and rocked for 10 min at 4° C. After sonication, the suspended material, containing both soluble and chromatin-bound protein, was analyzed as nuclear extract. Proteins in the nuclear and cytoplasmic extracts were analyzed by 8.5% SDS-PAGE, followed by western blotting with antibodies against α-tubulin, PCNA (both Santa Cruz Biotechnology), and recombinant HDHB.
Protein Phosphatase Reactions
FLAG-HDHB bound to anti-FLAG beads was incubated with 100 U of λ-phosphatase (New England Biolabs, Beverly, Mass.) in phosphatase buffer (50 mM Tris-HCl [pH 7.5], 0.1 mM EDTA, 0.01% NP-40) for 1 h at 30° C. The reaction was carried out in the presence or absence of phosphatase inhibitors (5 mM Na3VO4, 50 mM NaF). The proteins were separated by 7.5% SDSPAGE (acrylamide-bisacrylamide ratio, 30:0.36) and HDHB was detected by western blotting with anti-HDHB-peptide serum and chemiluminescence.
Tryptic Peptide Mapping and Phosphoamino Acid Analysis
At 24 h after transfection, radiolabeled FLAG-HDHB-transfected cultures to be used for immunoprecipitation and phosphoamino acid or phosphopeptide mapping were processed as above, except that lysis buffer was substituted by RIPA buffer (50 mM Tris-HCl [pH7.5], 150 mM NaCl, 1% NP-40, 0.5% deoxycholic acid, 1% SDS, 50 mM NaF, 1 mM EDTA, 5 mM Na3VO4, 100 μg/ml PMSF, 1 μg/ml aprotinin, and 1 μg/ml leupeptin). Immunoprecipitated proteins were separated by 7.5% SDS-PAGE and transferred to PVDF membranes. The membranes containing radiolabeled HDHB were rinsed well with deionized H 2 O twice before visualization of phosphoproteins by autoradiography. The phosphoproteins were then excised, and the membrane pieces were re-wet with methanol followed by water. The membranes were blocked with 50 mM NH4HCO3 containing 0.1% Tween 20 (Sigma-Aldrich) for 30 min at room temperature and washed three times with 50 mM NH4HCO3 before enzymatic cleavage of phosphoproteins from the PVDF with L-(tosylamido-2-phenyl)ethyl chloromethyl ketonetreated bovine pancreatic trypsin (Worthington, Lakewood, N.J.). The peptides were then subjected to two-dimensional phosphopeptide mapping or phosphoamino acid analysis as described in detail elsewhere (Boyle et al., Meth. Enzymology, (1991), 201, 110-149).
Cyclin-Dependent Kinase Reactions In Vitro
Kinase reactions using purified cyclin/CDK (200 pmol/h) (provided by R. Ott and C. Voitenleitner) and purified recombinant HDHB (Taneja et al., J. Biol. Chem., (2002) 277, 40853-40861) as the substrate were performed as described previously (Voitenleitner et al., Mol. Cell. Biol., (1999), 19, 646-56).
BrdU Labelling, Identification of Chemical Cell Cycle Blocks and RNAi Experiments on Stable Cell Lines
Stable cells expressing the pCORON1002-EGFP-C1-PSLD construct, were seeded at 0.3×105/ml in 96-well Greiner plates using antibiotic-free medium (100 μl/well) and incubate for 16 hours.
To demonstrate the distribution of EGFP-PSLD in S-phase, stable cells were marked with BrdU for 1 hr using the cell proliferation kit (Amersham Biosciences, GE Health Care). Cells were fixed in 2% formalin and incorporated BrdU was detected by immunofluorescence with a Cy-5 labelled secondary antibody system (Cell proliferation kit; GE Health Care). Nulcei were stained with hoechst (2 μM).
For chemical block studies (Table 1), stable cells were exposed to olomoucine, roscovitine, nocodazole, mimosine, colcemid or colchicine (Sigma). Cells were fixed in 2% formalin and nulcei stained with hoechst (2 μM).
For siRNA studies, siRNA pools (Dharmacon) against certain cyclins, MCM proteins, CDKs, polo-like kinase (PLK), and a random control duplex (Table 2) were diluted in lipofectamine/optimem I (Invitrogen) to 25 nM and added to stable cells for 4 hrs. The medium was replaced and plates incubated for 48 hr. Cells were fixed in 2% formalin and nulcei stained with hoechst (2 μM).
After highthroughput imaging and analysis on the IN Cell Analyzer system (GEHC), data for average nuclear intensity and N:C ratio (EGFP signal), nuclear size (hoescht signal) and, where appropriate, nuclear signal intensity (BrdU) were obtained for the total number of individual cells in a field of view using hoescht as a nuclear mask and the IN Cell Analyzer 3000 cell cycle phase marker algorithm (GEHC). For each well, the total number of cells per field of view were catagorised into G1-phase (predominantly nuclear EGFP distribution; high EGFP-PSLD nuclear intensity and N:C ratio), S-phase (nuclear BrdU signal >3SDs above background; EGFP-PSLD N:C ratio around 1) and G2-phase (large nuclear size; low EGFP-PSLD N:C ratio). Although it was possible to differentiate M-phase cells (based on small nuclear size and very intense EGFP signal) very few such cells were seen in wells fixed with formalin since they were removed during the washing and fixation process.
Results
HDHB Resides in Nuclear Foci or in the Cytoplasm
To determine the subcellular localization of endogenous HDHB, nuclear and cytoplasmic proteins were selectively extracted from human U2OS cells, separated by denaturing gel electrophoresis, and analyzed by western blotting ( FIG. 1 ). The presence of PCNA and α-tubulin in each extract was first monitored to assess the extraction procedure. PCNA was enriched in the nuclear extract and not in the cytoplasmic fraction, while α-tubulin was found primarily in the cytoplasmic fraction, validating the fractionation. HDHB was detected in both the nuclear and cytoplasmic fractions ( FIG. 1 ). The cytoplasmic HDHB migrated more slowly than the nuclear fraction ( FIG. 1 ), suggesting the possibility of post-translational modification.
These results could indicate either that HDHB was distributed throughout the cell, or that a mixed population of cells contained HDHB in either the nucleus or the cytoplasm. To distinguish between these alternatives, HDHB was localized in situ in single cells; GFP- and FLAG-tagged HDHB were expressed in human U2OS cells by transient transfection. Since prolonged over-expression of tagged or untagged HDHB was cytotoxic, all experiments were conducted in the shortest time period possible (usually 24 h). Tagged HDHB localization was analyzed in individual cells by fluorescence microscopy. Both GFP-HDHB and FLAG-HDHB displayed two major patterns of localization, either in the nucleus in discrete foci or in the cytoplasm ( FIG. 1 ). GFP-HDHB transiently expressed in primary human fibroblasts was also observed in either the nucleus or the cytoplasm.
Identification of a Cell Cycle-Dependent Subcellular Localization Domain in HDHB
U2OS cells were arrested in G2/M with nocodazole, released into G1 for three hours, and then microinjected with pGFP-HDHB DNA into their nuclei. GFP-HDHB expression was easily detectable six hours later, when approximately 70% of G1 phase cells had accumulated the fusion protein primarily in the nuclei ( FIG. 2 ). In contrast, when cells were synchronized at G1/S with thymidine, released into S phase, and then microinjected with pGFP-HDHB DNA, more than 70% of S phase cells had accumulated the fusion protein predominantly in the cytoplasm ( FIG. 2 ). Selective extraction of U2OS cells in G1 and S phase revealed that endogenous HDHB was mostly nuclear in G1 and cytoplasmic in S phase ( FIG. 2 b ). However, endogenous HDHB was clearly detectable in both subcellular fractions. The mobility of the S phase HDHB was slightly retarded compared to the G1 phase protein. These results indicate that the subcellular localization of HDHB is regulated in the cell cycle and that GFP-tagged HDHB reflects the localization of the endogenous untagged helicase.
Prompted by the identification of C-terminal nuclear location signals in Bloom's syndrome helicase and other RecQ-family helicases (Hickson, Nature Rev. Cancer, (2003) 3, 169-178), a possible subcellular localization domain (SLD) was identified at the extreme C-terminus of HDHB ( FIG. 3 ). To determine whether this putative SLD was important for HDHB localization, a truncation mutant of HDHB (GFP-HDHB-.SLD) was generated that lacks the C-terminal 48 residues containing the SLD ( FIG. 3 ). The expression vector was microinjected into U2OS cells in G1 or S phase and the subcellular localization of the fusion protein was examined by fluorescence microscopy six hours later. Over 95% of the cells accumulated the fusion protein in the cytoplasm, regardless of the cell cycle timing of HDHB expression ( FIG. 3 c ). This result suggests that HDHB may carry a NLS that is impaired or abolished by the C-terminal deletion in GFP-HDHB-ASLD.
To determine whether the C-terminal domain of HDHB was sufficient for nuclear localization, a bacterial β-galactosidase (βgal) was used as a reporter protein because it has a molecular mass (112 kDa) close to that of HDHB and does not contain subcellular localization signals (Kalderon et al., Cell, (1984), 39, 499-509). As a control, a GFP-βGal expression vector ( FIG. 3 ) was created and the subcellular localization of the fusion protein monitored after microinjection of the expression vector into U2OS cells. As expected, GFP-βGal protein accumulated primarily in the cytoplasm ( FIG. 4 ). In contrast, GFP-βGal-SLD was found in both the nucleus and cytoplasm in asynchronous or synchronized U2OS cells ( FIG. 4 ), suggesting that SLD contains a NLS, but was not sufficient for nuclear localization of the reporter protein. Reasoning that perhaps the neighboring potential CDK phosphorylation sites might affect subcellular localization in the cell cycle ( FIG. 3 ), a GFP-βGal-PSLD was constructed, in which the C-terminal 131 residues of HDHB, containing the putative SLD and the cluster of potential CDK phosphorylation sites, were appended to the C-terminus of GFP-βGal ( FIG. 3 ). When the GFP-βGal-PSLD plasmid DNA was transiently expressed in asynchronous and synchronized U2OS cells, GFP-βGal-PSLD was found in the nucleus in over 90% of G1 phase cells, and in the cytoplasm in more than 70% of S phase cells ( FIG. 4 ). In contrast with the focal pattern observed for nuclear GFP-HDHB in G1, GFP-βGal-PSLD and EGFP-PSLD proteins were distributed evenly throughout the nucleus in G1, sparing only the nucleoli. Analysis of stable cell lines expressing pCORON1002-EGFP-C1-PSLD that have been marked with BrdU emphasized that cells in S-phase (equal to approx 60% of the asychronous population) exhibit equidistribution or predominantly cytoplasmic distribution of the EGFP-PSLD signal ( FIG. 10 ). S-phase cells do not show a predominantly nuclear distribution of EGFP-PSLD associated with G1 cells. Some cells were seen to exhibit absolute nuclear exclusion of the EGFP-PSLD reporter ( FIG. 10 ) however these cells did not incorporate BrdU. We hypothesised that cells demonstrating absolute clearance of EGFP-PSLD from the nucleus were in G2. Kinetic imaging of the EGFP-PSLD stable cell lines over 24 hours showed that EGFP-PSLD is predominantly nuclear in G1 after mitosis, exhibits a rapid nuclear to cytoplasmic movement around the G1/S transition (˜3.5 hours after cytokinesis) and further progressive translocation from the nucleus to the cytoplasm from G1/S through to the end of G2 (approx 19 hours); at this point cell rounding occurred prior to re-division. These observations seem to confirm the possibility that G2 cells exhibit an absolute cytoplasmic distribution of the EGFP-PSLD reporter. Stable expression of the EGFP-PSLD fusion was not found to affect the total length of the cell cycle (approx 24 hours) when compared to U2OS cells or the G2M cell cycle phase marker cell line (GEHC). Taken together, these data suggest that the subcellular localization of HDHB is dependent on the cell cycle, that the C-terminal PSLD domain of HDHB plays a major role in regulating the subcellular localization of the protein in a cell cycle dependent manner and that HDHB is nuclear in G1 but progressively translocates to the cytoplasm during S-phase and possibly G2.
Identification of a Functional Rev-Type NES in HDHB
A number of proteins that shuttle between the nucleus and cytoplasm have been demonstrated to contain a NES similar to the prototype NES of HIV rev protein ( FIG. 5 ). Proteins containing a rev-type NES require the export factor CRM1 (also called exportin 1) to bind and transport proteins from the nucleus to the cytoplasm (reviewed by Weis, Cell, (2003), 112, 441-451). Leptomycin B (LMB), specifically inhibits CRM1 activity in nuclear protein export (Wolff et al., Chem. Biol., (1997), 4, 139-147; Kudo et al., Exp. Cell. Res., (1998), 242, 540-547). Inspection of the PSLD sequence in HDHB revealed a putative rev-type NES (LxxxLxxLxL; FIG. 5 ). To determine whether the cytoplasmic localization of HDHB requires a functional NES, expression plasmids for GFP-HDHB or FLAG-HDHB DNA were microinjected into asynchronous, G1, and S phase cells in the presence and absence of LMB. The localization of the fusion proteins was examined by fluorescence microscopy and quantified. In the presence of LMB, both fusion proteins accumulated in the nucleus independently of the cell cycle ( FIG. 5 ), consistent with the possibility that HDHB contains a rev-type NES that functions through CRM1. However it is also possible that HDHB may not be a direct cargo of CRM1 and that its export may be indirectly mediated through some other protein(s). To assess whether the putative NES in HDHB was functional, we mutated Val/Leu and Leu/Leu of the NES motif to alanine to create NES mutants 1 and 2 ( FIG. 5 ). GFP-HDHB and GFP-βGal-PSLD harboring these NES mutations were transiently expressed in either asynchronous or synchronized U2OS cells. Both NES mutant fusion proteins accumulated in the nucleus in more than 80% of cells, no matter when they were expressed in asynchronous or synchronized cells ( FIG. 5 ). The results indicate that the NES mutations specifically impaired the export of both GFP-HDHB and GFP-βGal-PSLD, arguing that the PSLD region of HDHB contains a functional NES.
FLAG-HDHB is Phosphorylated in a Cell Cycle-Dependent Manner In Vivo.
The cluster of potential CDK phosphorylation sites in the PSLD domain of HDHB ( FIG. 3 ) suggested that phosphorylation of HDHB might regulate its subcellular localization in the cell cycle. If so, one would expect the PSLD region of HDHB to be phosphorylated in a cell cycle-dependent manner. To test whether HDHB undergoes phosphorylation in PSLD, U2OS cells were transiently transfected with expression plasmids for wild type and C-terminally truncated forms of FLAG-HDHB, radiolabeled with phosphate, and then FLAG-HDHB was immunoprecipitated from cell extracts. Immunoprecipitated proteins were analyzed by denaturing gel electrophoresis, immunoblotting, and autoradiography ( FIG. 6 ). A radiolabeled band of FLAG-HDHB was detected at the same position as the immunoreactive HDHB band ( FIG. 6A , lanes 1). Truncated FLAG-HDHB lacking SLD was also robustly phosphorylated in vivo (lanes 2), while truncated FLAG-HDHB (1-874) lacking PSLD was not significantly phosphorylated (lanes 3). These results demonstrate that SLD is not required for HDHB phosphorylation, while PSLD is required, and suggest that the phosphorylation sites probably reside in PSLD.
To examine the timing of HDHB phosphorylation in the cell cycle, it would be convenient to detect phosphorylation without the use of radiolabeling. Since phosphorylation often reduces the electrophoretic mobility of a protein in denaturing gels, transiently expressed FLAG-HDHB was immunoprecipitated and its mobility examined before and after treatment with λ-phosphatase (λ-PPase) ( FIG. 6B ). Without λ-PPase treatment, FLAG-HDHB was detected in western blots in two very closely migrating bands (lane 1), while dephosphorylated FLAG-HDHB migrated as a single band at the mobility of the faster band of the doublet (lane 2). When λ-PPase inhibitors were present in the reaction, FLAG-HDHB migrated as a doublet identical to the mock-treated protein (lane 3). These data suggest that the electrophoretic mobility of FLAG-HDHB was reduced by phosphorylation and that this assay may be suitable to track HDHB phosphorylation in the cell cycle.
To determine whether HDHB is phosphorylated in a cell cycle-dependent manner, U2OS cells transiently expressing FLAG-HDHB were arrested in G1/S by adding thymidine to the medium or in G2/M by adding nocodazole to the medium. The cells were released from the blocks for different time periods, and FLAG-HDHB was immunoprecipitated from cell extracts.
The immunoprecipitated material was incubated with or without λ-PPase and then analyzed by denaturing gel electrophoresis and western blotting ( FIG. 6C ). The mobility of FLAG-HDHB from cells arrested at G1/S was increased by λ-PPase treatment, suggesting that the protein was phosphorylated at G1/S ( FIG. 6C , upper panel). A similar mobility shift was detected after phosphatase treatment of FLAG-HDHB for at least nine hours after release from the G1/S block (upper panel), as well as in cells arrested at G2/M ( FIG. 6C , lower panel). However, after the cells were released into G1 for four and eight hours, FLAG-HDHB migrated as a single band that was much less affected by phosphatase treatment ( FIG. 6C , lower panel). By twelve hours after release from the G2/M block, when most of the cells were entering S phase (data not shown), the mobility of FLAG-HDHB was again increased by phosphatase treatment, restoring the pattern observed in nocodazole-arrested cells (lower panel). These results strongly suggest that phosphorylation of FLAG-HDHB is cell cycle-dependent, with maximal phosphorylation from G1/S through G2/M and minimal phosphorylation during G1.
Serine 967 is the Major Phosphorylation Site of Ectopically Expressed HDHB.
To map the phosphorylation sites in FLAG-HDHB, we first wished to determine what amino acid residues were modified. Phosphoamino acid analysis of in vivo radiolabeled FLAG-HDHB revealed that phosphoserine(s) was the major phosphoamino acid of FLAG-HDHB in vivo ( FIG. 7A ). Assuming that the cell cycle-dependent phosphorylation sites of HDHB are located in PSLD between residues 874 and 1039 ( FIG. 3A ), that these sites are modified by CDKs, and that phosphoserine is the major amino acid modified ( FIG. 7A ), only four of the seven potential CDK sites would remain as candidate sites. To test each of these sites individually, FLAG-HDHB expression plasmids with the corresponding serine to alanine mutations were constructed. Cells transiently transfected with these plasmids were radiolabeled with orthophosphate in vivo and FLAG-HDHB was immunoprecipitated and analyzed by autoradiography and western blotting ( FIG. 7B ). The results showed that FLAG-HDHB and three of the mutant proteins were phosphorylated approximately equally, while the S967A mutant protein was only weakly phosphorylated ( FIG. 7B ). This result suggested that S967 might be the primary site of HDHB phosphorylation in vivo. Consistent with this interpretation, an electrophoretic mobility shift after phosphatase treatment of immunoprecipitated FLAG-HDHB was detected with three of the mutant proteins, but not with S967A protein.
To confirm that S967 was the major phosphorylation site in HDHB in vivo, tryptic phosphopeptide mapping was carried out with wild type and S967A mutant FLAG-HDHB that had been metabolically radiolabeled with orthophosphate ( FIG. 7C ). One predominant radiolabeled peptide and a weakly labeled peptide were observed with the wild type protein (left panel). The predominant phosphopeptide was absent in the S967A protein, but the weakly labeled peptide remained detectable ( FIG. 7C , right panel). The results provide additional evidence that serine 967 is a prominent phosphorylation site in HDHB in vivo.
Identification of Cyclin E/CDK2 as a Kinase that Potentially Modifies HDHB in G1/S
To test whether CDKs can actually modify HDHB, as suggested by the timing of HDHB phosphorylation in the cell cycle and the identification of S967 as a primary site of modification, purified cyclin E/CDK2 or cyclin A/CDK2 were incubated with purified recombinant HDHB and radiolabeled ATP in vitro. After the kinase reactions, the proteins were separated by denaturing gel electrophoresis, transferred to a PVDF membrane, and detected by autoradiography. The results revealed that recombinant HDHB could be phosphorylated strongly by both cyclin E/CDK2 and cyclin A/CDK2. The radiolabeled HDHB bands were then further processed for tryptic phosphopeptide mapping. Peptides from each digestion were separated in two dimensions, either individually or after mixing with tryptic peptides from in vivo phosphorylated FLAG-HDHB, and visualized by autoradiography ( FIG. 8A ). HDHB peptides phosphorylated by cyclin E/CDK2 and cyclin A/CDK2 yielded patterns essentially identical to those observed in the in vivo labeled peptide map, with one major spot and one minor spot ( FIG. 8A ). When the in vitro and in vivo labeled peptides were mixed and separated on one chromatogram, they co-migrated ( FIG. 8A , right). These data argue that the major phosphopeptides modified in vitro by cyclin E/CDK2 and cyclin A/CDK2 in purified recombinant HDHB were the same ones modified in vivo in FLAG-HDHB.
Since cyclin E activity in human cells rises in late G1, while cyclin A activity rises later coincident with the onset of S phase (Pines, 1999; Erlandsson et al., 2000), it was important to try to distinguish whether one of these kinases might preferentially modify HDHB. Cyclin subunits frequently form a complex with the substrate proteins that they target for phosphorylation (Endicott et al., 1999; Takeda et al., 2001). To test whether cyclin E or cyclin A could associate with HDHB, FLAG-HDHB and associated proteins were immunoprecipitated from extracts of cells transfected with either FLAG-HDHB expression vector or empty FLAG vector as a control. The cell extracts and the immunoprecipitated material were analyzed by western blotting ( FIG. 8B ). Cyclin E clearly co-precipitated with FLAG-HDHB, but cyclin A did not ( FIG. 8B , lanes 2 and 5), suggesting that FLAG-HDHB may interact preferentially with cyclin E in vivo. It is conceivable that this interaction may be required for phosphorylation of HDHB by cyclin E/CDK2 in vivo, and if so, mutations in HDHB that prevent its association with cyclin E would abrogate phosphorylation by cyclin E/CDK2. To test the possibility that the FLAG-HDHB mutant S967A was not phosphorylated in vivo ( FIGS. 7B , C) due to an inability to bind to cyclin E, FLAG-HDHB-S967A and associated proteins were immunoprecipitated from extracts of transfected cells and analyzed by western blotting. Co-precipitation of cyclin E with the mutant protein was as robust as with wild type FLAG-HDHB.
Phosphorylation of Serine 967 is Critical for Regulation of HDHB Localization.
The data above indicate that subcellular localization and phosphorylation of ectopically expressed HDHB were regulated in a cell cycle-dependent manner with maximal phosphorylation from G1/S to G2/M, coinciding with the period when HDHB accumulated in the cytoplasm. These results, together with the identification of S967 as the major in vivo phosphorylation site in HDHB, suggest that phosphorylation of S967 may regulate the subcellular localization of HDHB. To test this idea, expression plasmids for wild type GFP-HDHB and the mutants S967A, S984A, S1005A, and S1021A were microinjected into synchronized U2OS cells. Wild type GFP-HDHB accumulated in nuclear foci of cells in G1, but in the cytoplasm of cells in S phase as expected. However, regardless of cell cycle timing, GFP-HDHB-S967A localized in nuclear foci in about 70% of the fluorescent cells ( FIG. 9 ). The other three substitution mutants localized in either the nucleus or the cytoplasm like wild type GFP-HDHB. In an attempt to mimic the phosphorylation of S967, serine 967 was mutated to aspartic acid, GFP-HDHB-S967D was expressed in asynchronous and synchronized U2OS cells, and the subcellular distribution of the mutant fusion protein was examined.
About 60% of the cells expressing GFP-HDHB-S967D displayed cytoplasmic fluorescence in asynchronous, G1 phase, and S phase cells ( FIG. 9A ), demonstrating that the S967D mutation mimicked phosphorylated S967. The data strongly suggest that phosphorylation of serine 967 is critical in regulating the subcellular localization of HDHB.
A C-terminal Domain of HDHB Confers Cell Cycle-Dependent Localization
A 131-residue domain, PSLD, is sufficient to target HDHB, EGFP or a βGal reporter to either the nucleus or the cytoplasm in a cell cycle-dependent manner ( FIGS. 4 and 10 ). A rev-type NES resides in this domain ( FIG. 5 ), but its activity or accessibility to the nuclear export machinery depends on phosphorylation of PSLD, primarily on serine 967, at the G1/S transition ( FIGS. 6-9 ). S967 is a perfect match to the consensus CDK substrate recognition motif (S/T)PX(K/R). Both cyclin E/CDK2 and cyclin A/CDK2 can modify HDHB in vitro, but the ability of cyclin E/CDK2 to complex with HDHB in cell extracts suggests that it may be the initial kinase that modifies HDHB at the G1/S transition ( FIG. 8 ). Addition of olomoucine and roscovitin, known Cdk2 inhibitors (Table 1), or siRNA toward cyclin E (Table 2) resulted in predominantly nuclear distribution of EGFP-PSLD and arrest in G1 for EGFP-PSLD stable cell lines, further supporting the possibility that Cdk2/cyclin E is responsible for control of the observed cell-cycle based phosphorylation-dependent subcellular localisation. Phosphorylation of PSLD appears to persist through the latter part of the cell cycle, correlating well with the predominantly cytoplasmic localization of HDHB in S and G2. Kinetic imaging of stable cell lines treated with olomoucine over 24 hours showed that, for cells arrested in G2 the EGFP-PSLD signal redistributes from the cytoplasm to the nucleus over ˜4-8 hours (without the cell passing through mitosis) suggesting that in the absence of cdk2 activity the EGFP-PSLD either becomes dephosphorylated and re-enters the nucleus, or is destroyed and newly synthesised protein is not phosphorylated due to cdk2 inhibition and therefore locates in the nucleus.
TABLE 1
%
Total
Compound
S
G1
G2
cells
Colcemid (0.3 μM)
41
16
43
490
Colcemid (1.2 μM)
32
8
59
450
Colchicine (4 μM)
36
9
55
467
Colchicine (100 μM)
32
12
57
439
L-mimosine (2 mM)
68
6
26
1710
Olomoucine (500 μM)
33
63
4
600
Roscovitin (100 μM)
36
52
13
693
Nocodazole (3 μM)
33
6
61
606
Control
61
17
22
2137
TABLE 2
%
Total
siRNA
S
G1
G2
cells
PLK
53
9
38
66
MCM7
58
13
29
231
MCM6
64
14
22
166
MCM5
63
17
20
260
MCM4
56
20
24
223
MCM3
59
23
19
188
MCM2
50
24
26
266
Cyclin B1
49
36
15
280
V2
Cyclin B1
60
24
17
203
V1
CDK8
50
23
27
299
CDK7
56
18
26
354
CDK6
58
22
20
328
Cyclin A2
61
13
26
319
Cyclin A1
66
10
24
298
Cyclin T2b
57
12
31
267
Cyclin T2b
55
22
23
355
cyclinT1
60
20
20
260
cyclinE1
49
27
24
272
Control
69
10
20
262
It was not possible to distinguish whether HDHB undergoes dephosphorylation at the M/G1 transition ( FIG. 6C ) or is perhaps targeted for proteolysis and rapidly re-synthesized in early G1, when it would enter the nucleus. However, kinetic imaging of stable cell lines over 24 hours showed that the EGFP-PSLD signal is not greatly reduced during M phase or at the M/G1 boundary, but becomes predominantly nuclear approximately 30 minutes after cytokinesis (this state then persists for ˜3 hours during G1), coincident with nuclear membrane formation. This indicates that the EGFP-PSLD construct is dephosphorylated rather than undergoing significant destruction around the M/G1 boundary.
These data provide strong evidence that the PSLD contains active targeting signals that are independent of protein context ( FIG. 2-5 , 10 ). Since mutant HDHB with an inactivated NES is nuclear even when it is expressed during S phase and thus presumably phosphorylated ( FIG. 5 ), it is probable that the NLS is not inactivated by phosphorylation and that the primary target of CDK regulation is the NES. Extending this reasoning, the NES may be masked during G1 when the CDK motifs in PSLD are unmodified, and that the NES is liberated when S967 becomes phosphorylated, leading to NES recognition by nuclear export factors ( FIGS. 3-5 ). Structural studies of a rev-type NES have shown that it forms an amphipathic α-helix, with the leucines aligned on one side of the helix and charged residues on the other side (Rittinger et al., Mol. Cell. Biol. (1999), 4, 153-166). Since the SLD of HDHB contains both the rev-type NES and an NLS, and the basic residues likely to serve as the NLS are interspersed through the NES, the NES and NLS may reside on opposite faces of an amphipathic helix. Additional sequences in PSLD would mask the NES intramolecularly, allowing only the NLS to be recognized. Phosphorylation of S967 would alter the conformation of the mask in PSLD to expose the NES, without affecting exposure of the NLS.
High Throughput Screening for Inhibitors of the Cell Cycle with EGFP-PSLD Stable Cell Lines
As stated above, working with transiently transfected cells proved difficult in multiwell plate format due to low transfection efficiency, heterogeneity of expression and problems arising from the high throughput analysis of such data. Screening for the effects of large numbers of siRNA or agents upon the cell cycle therefore required production of a homogenous stable cell line. A stable cell line was generated with the PSLD region linked to a reporter (EGFP) via a flexible seven amino acid linker (using pCORON1002-EGFP-C1-PSLD). As can be seen from FIG. 13 , the fluorescent signal generated by the stable cell lines developed with pCORON1002-EGFP-C1-βGal-PSLD was significantly smaller (approximately ten-fold) than that produced by cells lines having the flexible seven amino acid linker. This is probably due to the size of the βGal protein placing large demands upon the transcriptional and translational machinery of the cell.
A stable cell line developed with pCORON1002-EGFP-C1-PSLD (see FIG. 13 ) was homogeneous (average total cell RFU 435, SD 58; n=271; see FIG. 10 ) in nature and provided sensitive, stable and uniform assays for investigating the cell cycle and for rapidly screening the effect of agents upon the cell cycle in mutliwell plate format (Tables 1 and 2; and FIG. 10 ).
Certain aspects of the invention disclosed hereinabove has been published in Molecular Biology of the Cell (15: 3320-3332, July 2004) and electronically published as MBC in press, 10.1091/mbc.E04-03-0227 on May 14, 2004, under the title of “Cell Cycle-dependent Regulation of a Human DNA Helicase That Localizes in DNA Damage Foci”, the disclosure of which is incorporated herein by reference in its entireties.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will 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 claims. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein. | The present invention relates to polypeptide and nucleic acids constructs which are useful for determining the cell cycle status of a mammalian cell. Host cells transfected with these nucleic acid constructs can be used to determine the effects that test agents have upon the mammalian cell cycle. | 2 |
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